NRRPT Prep Applied Radiation Protection

Question Number: 890 Applied Radiation Protection The DOE beta-gamma removable contamination limit is: 2 A) 16.7 Bq/100 cm B) 8.3 Bq/100 cm2 C) 0.83 Bq/100 cm2 D) 33.4 Bq/100 cm2 E) 83.5 Bq/100 cm2

The correct answer is: A 1000 dpm/100 cm2 = 16.7 Bq/100 cm2

Question Number: 881 Applied Radiation Protection An individual has received an intake of 2 ALIs in the last 24 hours. You must notify the NRC within: A) 24 hours. B) an hour. C) one week. D) ten working days. E) a month.

The correct answer is: A 24 hour notification is required for acute doses greater than one time the annual occupational limit, but less than five times the limit - at which time immediate notification is required. 10 CFR Part 20.2202

Question Number: 989 Applied Radiation Protection A source contains 3.7 mCi of Cs-137. This is the same as: A) 136.9 MBq B) 10 pBq C) 136.9 kBq D) 3.7 MBq E) 1000 mBq

The correct answer is: A 3.7 mCi = 0.0037 Ci. 0.0037 Ci * 3.7×1010 Bq/Ci = 136.9 × 106 Bq

Question Number: 928 Applied Radiation Protection 10 CFR 20 exposure limits for minors are based on what percentage of the adult occupational limits? A) 5% B) 10% C) 15% D) 20% E) 25%

The correct answer is: B These limits are for occupational radiation exposure of minors. 10 CFR Part 20.1207

Question Number: 825 Applied Radiation Protection ICRP recommends a weighting factor of 0.01 for assessing stochastic risk to skin. This means: A) radiogenic skin cancer is a low risk. B) radiogenic skin cancer is a high risk. C) spontaneous skin cancer is a low risk. D) radiogenic skin cancer exceeds spontaneous skin cancer as a risk. E) dose equivalent to the whole body is 100 times dose to the skin.

The correct answer is: A A weighting factor of .01 indicates that the proportion of risk of cancer to the skin to the risk of all cancers at a given dose equivalent is 1 in 100. This indicates that radiation-induced skin cancer is a low risk compared to other radiation-induced cancers.

Question Number: 934 Applied Radiation Protection All of the following, with one exception, have been reported to be useful in monitoring the performance of the radiation protection program at a nuclear power plant. That exception is: A) the number of Certified Health Physicists on the staff. B) collective exposure. C) incidence of skin/clothing contamination. D) solid radwaste volume. E) radiological incident reports.

The correct answer is: A All other choices are quantifiable indicators of the effectiveness of a facility RP program.

Question Number: 817 Applied Radiation Protection When is a neutron radiation survey usually performed? A) After reactor startup B) Upon receipt of a radioactive materials shipment C) When there are suspected fuel cladding failures within the active fuel inside the reactor D) Before an object is released from a controlled area E) None of the above

The correct answer is: A As the reactor goes through its power ascension, neutron dose rates in surrounding areas will increase. If control rods are in a different configuration than during the previous reactor run, the location of the neutron fields will most likely be different.

Question Number: 861 Applied Radiation Protection The most sensitive technique for analyzing intakes of C-14 are: A) exhalation. B) blood sample. C) urinalysis. D) fecal analysis. E) whole body count.

The correct answer is: A Breath analysis is the most sensitive technique via excretion of CO 2. Urinalysis is the next most sensitive and probably more practical. Bevelacqua, Contemporary Health Physics: Problems and Solutions. 1995.

Question Number: 821 Applied Radiation Protection World population exposures due to fallout Cs-137 from nuclear detonations can best be estimated by collecting samples of: A) cereals. B) milk. C) fish. D) meat. E) water.

The correct answer is: A Cereals have the greatest affinity for cesium of the materials listed. Illite clay in pond and river beds is also a useful indicator for cesium dispersion into the environment.

Question Number: 978 Applied Radiation Protection A wipe is taken where chlorine bleach was just used for cleaning. The wipe is then counted in a liquid scintillation counter which will most likely result in which of the following? A) Chemiluminescence and excess counts B) No problems since it will be "dark adapted" C) No counts, since chlorine bleach "neutralizes" scintillation fluid D) No effect, the sample will be valid E) A few extra counts that can be corrected

The correct answer is: A Chlorine bleach and certain other chemicals will react with Liquid Scintillation Counting Fluids and cause scintillations even when no radioactivity is present. Generally, very high count rates are encountered when chlorine bleach contamination of LSC scintillation liquids occurs.

Question Number: 852 Applied Radiation Protection Actions taken during a spill of highly enriched fissile material: A) should ensure that the spilled material does not reach a critical condition because of geometry and/or reflection. B) should require the immediate evacuation of all personnel from the area affected. C) should require securing the area and turning off the ventilation system. D) should require the collection and confinement of the material through whatever means are immediately available. E) should include immediate notification of the NRC.

The correct answer is: A Choices A through D are all valid responses, but Answer A is the most important since the release of energy from a criticality accident can be fatal. Contamination is a secondary concern.

Question Number: 802 Applied Radiation Protection In performing a preoperational radiological assessment for a nuclear facility, consideration is given to all of the following EXCEPT: A) Cosmic radiation levels B) Intake pathways to the public C) Baseline gamma radiation levels D) Presence of predominant radionuclides E) Gamma radiation anomalies

The correct answer is: A Cosmic radiation levels are fairly constant throughout the environment, and contribute only slightly to the total background radiation. All of the other distractors represent valid considerations.

Question Number: 870 Applied Radiation Protection Sample lines for plant vents must be designed to minimize sample line losses. As a general rule, the sample line should be designed to: A) maximize velocity and diameter, while minimizing distance. B) maximize velocity and distance, while minimizing diameter. C) maximizing velocity and distance, while minimizing tortuous paths. D) maximizing distance while minimizing diameter and tortuous paths. E) maximizing velocity while minimizing diameter and tortuous paths.

The correct answer is: A Depending on the line configuration, these factors may result in line losses ranging from 0 to 100% (ANSI N13.1). Maletskos, C.J.,Radiation Protection at Nuclear Power Plants.

Question Number: 833 Applied Radiation Protection State the purpose of the main steam line radiation monitors at a BWR. A) Detection of gross fuel failure B) Quantify steam release rates C) Indicate reactor power during accidents D) Serve area monitors near steam lines E) Quantify off-gas

The correct answer is: A During reactor fuel failure, a large amount of gamma-emitting fission products are released to the reactor coolant and exit the reactor through the main steam lines. An increase in the gamma readings at this location serves as an indication of fuel failure.

Question Number: 877 Applied Radiation Protection The effective dose equivalent allowed by EPA Protective Action Guides for life saving or protection of large populations where the individual is a volunteer and is fully aware of the risks involved is which of the following? A) > 250 mSv B) < 500 mSv C) < 250 mSv D) 250 mSv E) < 25 mSv

The correct answer is: A EPA 400 prescribes "no upper limit". Therefore, Answer A is best.

Question Number: 886 Applied Radiation Protection For those radionuclides for which submersion dose is limiting, the occupational DAC in Appendix B of 10 CFR 20 was divided by a factor of 219. The factor of 219 is composed of a factor of 50 to relate the 5-rem annual occupational dose limit to the 0.1 rem limit for members of the public, and a factor of 4.38 that relates: A) occupational exposure for 2000 hrs/yr to full time exposure. B) age considerations of individuals in submersion gas. C) clearance rates of workers for various work activities. D) daily exposure to yearly exposure. E) internal exposure to external exposure.

The correct answer is: A Factor 4.38 relates occupational exposure of 2,000 hours to full time exposure of 8,760 hours per year.

Question Number: 857 Applied Radiation Protection The target and filter material used in most x-ray mammography machines is, respectively: A) molybdenum, molybdenum. B) tungsten, molybdenum. C) tungsten, rhodium. D) rhodium, rhodium. E) molybdenum, rhodium.

The correct answer is: A Hendee, Health Physics Journal, 1995, Vol 69, No5: "Multiple studies of x-ray spectrum influence on radiation dose to patient and quality of the mammographic image has lead to widespread acceptance of dedicated mammographic x-ray units employing molybdenum-target x-ray tubes and molybdenum filters 90.03 mm thick) for the x-ray beam."

Question Number: 836 Applied Radiation Protection Comparative assessment of United States and foreign nuclear power plant occupational dose experience has indicated that reductions in out-of-core radiation fields can result in substantial reductions in occupational doses. Of the following actions, the one that is the LEAST effective in reducing out-of-core radiation fields is: A) hydrogen water chemistry. B) control of impurities in reactor coolant. C) preconditioning of out-of-core surfaces (polishing, prefilming). D) reduction or elimination of cobalt in reactor system components. E) chemical decontamination.

The correct answer is: A Hydrogen water chemistry is used to regulate reactor performance, rather than to reduce radiation fields. The other distractors are all ALARA engineering methods.

Question Number: 832 Applied Radiation Protection Lead and polyethylene are available to shield a source emitting 6.1 MeV gammas and neutrons of an average energy of 2.5 MeV. Which shielding arrangement listed below would be expected to yield the lowest overall dose rate? A) Polyethylene followed by lead B) Lead only C) Polyethylene only D) Lead followed by polyethylene E) No shielding is necessary since the 12" air gap will sufficiently scatter/attenuate the neutrons.

The correct answer is: A In this scenario, the fast neutrons should be shielded first by the hydrogenous polyethylene, then the lead to shield both the capture gammas and the 6.1 MeV gammas.

Question Number: 990 Applied Radiation Protection Radio-iodines are important in emergency management of radiation accidents because they: A) are a high yield fission product and concentrate in milk. B) have easily understood decay schemes. C) do not decay until several decades have passed. D) emit only gamma rays. E) cannot be shielded if outside the body.

The correct answer is: A Iodine will concentrate in cow's milk, and since children consume significant quantities of milk and have a small thyroid, large doses to children can occur in accidents. Additionally, iodines are volatile, and are among the first nuclides released in a reactor accident. See NCRP Report 138, or Gollnick.

Question Number: 866 Applied Radiation Protection The occupational limit for radon exposure in the United States is: A) 4 WLM/year. B) 1.3 x 105 MeV alpha/1 liter of air. C) 210 pci/liter per year. D) 0.02 WLM/year. E) 2 R/yr.

The correct answer is: A One working level-month produces about one rem CEDE. This limit, primarily for workers in the mining industry, appears in Title 30 of the Code of Federal Regulations (MSHA). See 30 CFR 57.5038

Question Number: 925 Applied Radiation Protection Radiobiological evidence suggests that, when compared to more uniform irradiation by the same quantity of radioactive material, highly localized beta irradiation of the skin, such as from a hot particle on the skin: A) is less likely to cause skin cancer. B) is more likely to cause skin cancer. C) is about equally likely to cause skin cancer. D) is likely to cause erythema within a few hours. E) is likely to cause a small necrotic lesion on the skin of an individual after only a few hours of exposure.

The correct answer is: A Localized activity produces high doses to a relatively small number of nearby cells, resulting in cell death. Uniform irradiation is likely to damage a larger number of cells without killing them, thus increasing the probability of the occurrence of cancer.

Question Number: 924 Applied Radiation Protection The most plausible explanation for the increasing frequency of detection of "hot particles" at nuclear power plants is: A) the increased use of more sensitive instrumentation for detecting and measuring contamination by these particles. B) an increase in the rate of production of these particles at nuclear power plants. C) the changes in plant chemistry that have enhanced fuel reliability but have increased the corrosion rate of other components. D) a decrease in the average corrosion particle size as plants have age. E) the trend toward increasing the time between refueling outages with a subsequent decrease in preventive maintenance.

The correct answer is: A More sophisticated portal, hand and foot, and laundry monitors with high sensitivity have had a significant effect on hot particle detection.

Question Number: 937 Applied Radiation Protection At a nuclear power reactor facility, which is the MOST important aspect of a respiratory protection program for limiting internal radiation dose? A) An adequate testing, fitting, and training program B) An adequate whole body counting program to ascertain that equipment is providing its reported degree of protection C) An adequate urinalysis program D) Requiring nose wipes of all individuals to ascertain that equipment is actually working E) Requiring, as a minimum, the use of particulate filter type respirators for all individuals entering the containment

The correct answer is: A NRC's NUREG 0041 addresses the elements of an effective respiratory protection program. It is important to verify that all devices used are capable of providing the rated protection factor for each individual wearing the device. It is also important that all individuals are trained in the proper use of each device, since the use of respiratory protection in itself presents a significant risk to the wearer. Respiratory protection should only be used after removal of the source and other engineering controls have been considered.

Question Number: 1000 Applied Radiation Protection Fission product noble gasses such as Kr-85: A) are mostly exhaled. B) deliver large doses to the lungs due to adsorption in the bloodstream. C) are a major concern at uranium mines. D) are a major concern at enrichment facilities. E) cannot be detected unless bonner spheres are used.

The correct answer is: A Nobel gasses are inert, and are not taken up in the body.

Question Number: 830 Applied Radiation Protection The FDA standard for microwave oven leakage at 5 cm or more from the external surface of the oven, prior to sale is: A) 1 mW/cm2 B) 5 mW/cm2 C) 10 mW/cm2 D) 20 mW/cm2 E) 100 mW/cm2

The correct answer is: A Once placed in operation, the limit is raised to 10 mW/cm 2, which is the TLV for microwaves.

Question Number: 834 Applied Radiation Protection Optimization techniques can be used to assure that: A) a radiation protection practice keeps radiation exposures as low as reasonably achievable (ALARA). B) the dose and resultant radiation detriment are minimized. C) the gross monetary benefit of a practice involving ionizing radiation is maximized. D) a cost of achieving a selected level of radiation protection is minimized. E) the basic production cost is minimized.

The correct answer is: A Optimization is a technique recommended by the ICRP in Publication 26 (1977). Cost-Benefit analysis in radiation protection is discussed in detail in Publication 37.

Question Number: 810 Applied Radiation Protection Which of the following radionuclides would present the least hazard as fallout from a nuclear weapon detonation? A) Pu-235 B) Cs-137 C) Zr-95 D) Sr-89/Sr-90 E) I-131

The correct answer is: A Pu-235 is the only non-fission product which appears as a response. Furthermore, it is the isotope 239, not 235, which is present in a nuclear weapon.

Question Number: 814 Applied Radiation Protection Which of the following is one function of the ALARA program? A) Train workers in methods to reduce exposure. B) Increase the number of qualified workers to reduce individual worker dose. C) Enable radiation workers to design shielding systems. D) Minimize a company's legal liability in accidents. E) Place total responsibility for ALARA upon the worker.

The correct answer is: A Regarding choice B, the risk should never be spread to a larger population to minimize individual dose. Regarding choice E, a management commitment to ALARA is the most important element of the ALARA program, and although it places some responsibility on the worker, most of the responsibility is on management.

Question Number: 840 Applied Radiation Protection Radiobiological evidence suggests that, when compared to more uniform irradiation by the same quantity of radioactive material, highly localized beta irradiation of skin, such as from a particle on the skin: A) is less likely to cause skin cancer. B) is more likely to cause skin cancer. C) is about equally likely to cause skin cancer. D) is likely to cause erythema within a few hours. E) is likely to cause a small necrotic lesion on the skin of an individual after only a few hours exposure.

The correct answer is: A Research has shown that irradiation from hot particles, discrete beta-emitting activation or fission product particles, are much more likely to create minor cosmetic changes to the skin than to cause skin cancer.

Question Number: 904 Applied Radiation Protection Which one of the following shapes represents the greatest hazard for a criticality accident? A) A sphere B) A disk C) A rectangular block D) A long thin cylinder E) A pyramid

The correct answer is: A Safe geometries include shapes that favor high neutron leakage out of the critical mass such as a flat disk or a long thin cylinder.

Question Number: 956 Applied Radiation Protection Knowledge of the characteristics of an ion source in an accelerator is important because: A) RF is commonly used to ionize the gas in the ion source and it may interfere with radiation detection instruments. B) if the output of the ion source is greater than several mega electron volts, radiological protection concerns are generally few, and limited to occupancy during accelerator operation. C) most low energy accelerators use a high energy accelerator as a source for the beam. D) most injectors are very high energy and present the majority of the hazard associated with accelerators. E) electron sources do not need to be checked for x-rays, since they are high power triode vacuum tubes.

The correct answer is: A See NCRP Report 144, pg. 19. All other statements are exactly opposite of a true situation.

Question Number: 851 Applied Radiation Protection The maximum protection factor that can be used against tritium oxide when wearing a supplied air hood is: A) 2 B) 10 C) 50 D) 100 E) 1000

The correct answer is: A Since absorption through the skin constitutes about one-half of the dose from exposure to tritium oxide, the maximum PF for inhalation protection is 2. Respiratory protection factors are found in 10 CFR Part 20 Appendix A.

Question Number: 849 Applied Radiation Protection If the most restrictive airborne radionuclide at a facility has a DAC of 7 x 10 -12 µCi /ml, a continuos air monitor at the facility should have an alarm set point at a count rate which indicates an airborne concentration of: A) 7.00 x 10-13 µCi /ml B) 1.75 x 10-12 µCi /ml C) 2.25 x 10-12 µCi /ml D) 5.25 x 10-12 µCi /ml E) 7.00 x 10-12 µCi /ml

The correct answer is: A Since personnel monitoring is required if an individual could exceed 10% of the annual limits, it makes sense to have in place a detection mechanism to identify when that threshold is reached. 7.00 x 10 -13 is 10% of the stated DAC in the question. DOE currently requires posting of airborne radioactivity areas at 0.1 DAC.

Question Number: 844 Applied Radiation Protection At a point outside a thick photon radiation shield the exposure due to primary photons is 0.25 of the exposure from secondary photons. What is the buildup factor at that point? A) 5 B) 4 C) 3 D) 2 E) 1

The correct answer is: A Since the buildup factor is the ratio of all photons at a point outside the shield to primary, unscattered photons at that point, B = all/primary B = (1 + 0.25)/0.25 B = 5

Question Number: 985 Applied Radiation Protection When using an ion chamber near a radio repeater: A) the RF from the repeater may cause the ion chamber to malfunction. B) it may cause radio transmissions to stop. C) interference with radio communications is expected, and alternative communications should be arranged for work in the area. D) the batteries in the ion chamber will recharge, sometimes very rapidly. E) the "clicks" from the ion chamber can be transmitted to all nearby radios.

The correct answer is: A Strong RF fields can cause false readings on ion chambers that are not RF shielded.

Question Number: 853 Applied Radiation Protection For regulatory compliance purposes, the "total organ dose equivalent" is BEST represented by the sum of: A) the deep dose equivalent and the committed dose equivalent. B) the deep dose equivalent and the committed effective dose equivalent. C) the effective dose equivalent and the deep dose equivalent. D) the shallow dose equivalent, the deep dose equivalent, and the effective dose equivalent. E) the shallow dose equivalent, the deep dose equivalent, and the committed effective dose equivalent.

The correct answer is: A The annual limit for the total organ dose equivalent (TODE) is 50 rem. It is the sum of the committed dose equivalent (from internal sources) and the deep dose equivalent (from external sources).

Question Number: 910 Applied Radiation Protection Protective actions for nuclear accidents are grouped into which of the following three time phases? A) Early, Intermediate, and Recovery B) Initial, Intermediate, and Recovery C) Initial, Interdiction, and Recovery D) Beginning, Middle, and End E) Early, Interdiction, and Recovery

The correct answer is: A The early phase lasts from hours to days after the accident. The intermediate phase lasts from weeks to months after the accident. The recovery phase lasts from months to years after the accident. (EPA-400) Johnson and Birky, Health Physics and Radiological Health .

Question Number: 829 Applied Radiation Protection To limit possible exposure to radiation from television receivers, the NCRP recommends that children sit no closer than: A) 6 feet. B) 5 feet. C) 4 feet. D) 3 feet. E) 2 feet.

The correct answer is: A The flyback transformer in a television set produces x-rays and are no longer used in television sets. This recommendation still exits, although the x-ray producing components of a television no longer exist today.

Question Number: 954 Applied Radiation Protection An evaluation is being made of various shielding materials for use in an experiment. The experiments are using photon emitters. Tracer amounts of the photon emitter are being used. The attenuation coefficient, µ, is one of the important considerations for shielding in the shielding equation I = I 0e-µt, since if µ is large, it means that the shielding: A) is an effective shield at that energy. B) is an ineffective shield at that energy. C) should not be used for shielding at that energy. D) has a buildup factor attenuation function. E) can shield less effectively at other energies.

The correct answer is: A The larger µ is, the better the shield for the given parameters.

Question Number: 953 Applied Radiation Protection A nuclear reactor plant has been having difficulty in meeting contamination control requirements. The beta dose rate at the surface of a bench top contaminated with Sr-90 (in equilibrium with Y-90) is 1 millirad per hour. The dose equivalent rate is: A) 1 millirem per hour B) 2 millirem per hour C) 5 millirem per hour D) 10 millirem per hour E) 20 millirem per hour

The correct answer is: A The quality factor is 1 for bets particles. US Nuclear Regulatory Commission: 10 CFR Part 20 Standards for Protection Against Radiation. Washington, DC: U.S. Government Printing Office.

Question Number: 945 Applied Radiation Protection The Radioactive Yellow II and III labels for packages of radioactive materials must contain the "transport index". The transport index is a measure of the: A) dose equivalent rate at one meter from the package surface. B) dose equivalent rate at one foot from the package surface. C) dose equivalent rate on contact with the package surface. D) number of curies in the package. E) total mass of radioactive material in the package.

The correct answer is: A The transport index is written in the "TI" box on the Radioactive Yellow II and III labels. In addition to the package surface radiation level, the TI determines the type of label to be applied to the package.

Question Number: 964 Applied Radiation Protection The most critical information required for selecting laser safety eye-wear is: A) wavelength, optical density. B) an ANSI Z87 rating. C) wavelength, proper density thickness. D) color, density thickness. E) ANSI Z87 rating and proper density thickness.

The correct answer is: A These are the only parameters that are required on safety glasses.

Question Number: 939 Applied Radiation Protection Doses to the thyroid and whole body used for the purpose of calculation of distance factors for power and test reactors are respectively: A) 300 rem and 25 rem B) 200 rem and 15 rem C) 100 rem and 10 rem D) 50 rem and 5 rem E) 10 rem and 1 rem

The correct answer is: A These limits are specified in 10 CFR Part 100, "Reactor Site Criteria." The Exclusion Radius is the radius from the release point where these limits would be exceeded in 2 hours following the onset of a postulated worst-case release. The Low Population Zone is defined for the entire duration of the release.

Question Number: 921 Applied Radiation Protection A safe geometry to prevent criticality accidents would be one that includes which of the following conditions? A) A geometry that maximizes the surface area to volume ratio B) A geometry that minimizes surface area to volume ratio C) A geometry that maximizes the presence of a moderator D) A geometry that maximizes the volume to surface ratio E) A geometry that maximizes the presence of a reflector

The correct answer is: A This configuration allows maximum neutron escape from the fissile mass, thereby reducing the possibility of criticality.

Question Number: 837 Applied Radiation Protection If personnel with doses less than 100 mrem/year are excluded, the average annual exposure for nuclear reactor workers is typically: A) 400-800 mrem. B) 750-1500 mrem. C) 1200-2400 mrem. D) 2000-3000 mrem. E) 2700-4000 mrem.

The correct answer is: A This estimate is reported in NCRP Report No. 101 (1989) based on 98,100 individuals exposed in nuclear power plants in 1984. More recent figures may indicate lower average doses.

Question Number: 917 Applied Radiation Protection According to 10 CFR 20, how often does the radiation protection program have to be reviewed? A) Annually B) Every 2 years C) Every 3 years D) Continuously E) Only once after implementation or after significant change to the program

The correct answer is: A This is a requirement of 10 CFR Part 20 Subpart B.

Question Number: 873 Applied Radiation Protection During the early phase of an accident, EPA recommends limiting workers performing emergency services to an effective dose equivalent for all activities at: A) 50 mSv. B) 100 mSv. C) 20 mSv. D) 250 mSv. E) 500 mSv.

The correct answer is: A This limit, equivalent to the annual occupational limit of 5 rem, can be found in EPA 400.

Question Number: 828 Applied Radiation Protection For students under the age of 18, the NCRP recommends that the whole body radiation dose from educational activities be limited to: A) 0.1 rems/yr B) 0.17 rems/yr C) 0.3 rems/yr D) 0.5 rems/yr E) 5.0 rems/yr

The correct answer is: A This recommendation is adopted in both NRC and DOE radiation protection regulations. It appears in NCRP Report No. 116 (1993), "Limitation of Exposure to Ionizing Radiation", which superseded Report No. 91 (1987).

Question Number: 995 Applied Radiation Protection After uranium conversion to UF 6, but prior to enrichment, the major immediate health hazard is: A) formation of HF acid in the lungs. B) criticality. C) neutrons. D) radon. E) Ar-41.

The correct answer is: A When UF6 comes in contact with water in the air and the lungs, it forms hydrofluoric acid, which will cause immediate injury to humans. At this point in the fuel cycle it is not enriched, so it is not a criticality hazard. Radium is separated at the mill, so no radon should be present.

Question Number: 703 Applied Radiation Protection An x-ray machine is operated in a closed room for several minutes. After the machine is turned off, how long should the operator wait before entering the room? A) He may enter immediately. B) 10 seconds C) 30 seconds D) 1 minute E) 1 hour

The correct answer is: A When the current to the x-ray tube is turned off, the production of electrons stops. The principle behind x-ray production in the tube is bremsstrahlung of these electrons with the target material. When the electron production stops, so does the x-ray production. There is, of course, no radioactive material in an x-ray machine.

Question Number: 883 Applied Radiation Protection The class "D" in Appendix B to 10 CFR 20 applies to a range of clearance half lives: A) < 10 days in the pulmonary region of lung. B) < 10 days in the lower intestine. C) < 1 day in the pulmonary region of lung. D) < 1 day in the trachea. E) < 1 day in the upper intestine.

The correct answer is: A Class "W" is for 10 to 100 days and class "Y" is for greater than 100 days.

Question Number: 926 Applied Radiation Protection Which of the following statements is NOT correct with regard to the administration of KI to off-site radiological survey team members? A) Some people can have an allergic reaction to KI. B) KI must be given before the intake starts to have a beneficial effect. C) KI has a definite shelf life. D) People who eat seafood regularly may already have their thyroid saturated with iodine. E) The risks of administering KI must be carefully balanced with the benefits of its use.

The correct answer is: B According to the FDA, to have the greatest effect in decreasing the accumulation of radioiodine in the thyroid gland, potassium iodide (KI) should be administered immediately before or after exposure. Johnson and Birky, Health Physics and Radiological Health .

Question Number: 818 Applied Radiation Protection Respiratory Protection Factors are found in: A) 10 CFR 20.101 B) 10 CFR 20 Appendix A C) 10 CFR 20 Appendix B D) 10 CFR 20 Appendix C E) 10 CFR 19.13

The correct answer is: B Appendix B lists Derived Air Concentrations (DACs) and Annual Limits on Intake (ALIs). Appendix C lists Quantities of Licensed Materials Requiring Labeling. 10 CFR 19 contains required Notices to Workers.

Question Number: 940 Applied Radiation Protection Respiratory Protection Factors for airborne radioactive material are found in: A) 10 CFR 20.101 B) 10 CFR 20 Appendix A C) 10 CFR 20 Appendix B D) 10 CFR 20 Appendix C E) 10 CFR 19.13

The correct answer is: B Appendix B lists derived air concentrations (DACs) and annual limits on intake (ALIs). Appendix C lists quantities of licensed materials requiring labeling. 10 CFR 19 contains required notices to workers.

Question Number: 884 Applied Radiation Protection The non-stochastic ALIs listed in Appendix B to 10 CFR 20 are designated: A) by an asterisk. B) with the name of the organ limited by the dose. C) by the letters "NS" after the value. D) by parentheses. E) by footnote number 3.

The correct answer is: B Appendix B to 10 CFR 20 Table 1 notes: "When an ALI is determined by the non-stochastic dose limit to an organ, the organ or tissue to which the limit applies is shown, and the ALI for the stochastic limit is shown in parentheses"

Question Number: 972 Applied Radiation Protection The line source and point source equations are useful for estimating dose rates. Approximately how far from a line source would you need to be before it can be considered a point source? A) At least two feet B) More than twice the major dimension of the line source C) Four times the major dimension (inverse square) D) Line sources are better estimates of point souces. E) Cannot be determined without additional information.

The correct answer is: B At more than twice the major dimension of the line source, it will easily approximate a point source. A thumb-rule from the Health Physics and Radiological Health Handbook in Chapter 3 uses the major dimension divided by 2.

Question Number: 859 Applied Radiation Protection Therapeutic radionuclides are used to deliver large doses of radiation in the treatment of cancer. Brachytherapy includes: A) placement of radioactive material in the brachial artery. B) placement of radioactive material in direct contact with tumors. C) inhalation of radionuclide to treat cancer of the bronchi. D) irradiation of cancer tumors with external sources of radiation. E) irradiation of bronchi by external radiation sources to treat lung cancer.

The correct answer is: B Brachytherapy is the treatment of cancer by the insertion of radioactive sources into tissues or cavities. NCRP Report 160, page 307.

Question Number: 922 Applied Radiation Protection Which of the following is NOT true concerning uranium fires? A) Machine turning and filings of uranium tend to be pyrophoric. B) C02 has been shown to be most effective in fighting a uranium fire. C) Halon may be explosive if directed at burning uranium. D) Immersing burning uranium in water may dissociate hydrogen and oxygen, supplying fuel for the fire. E) Uranium fires can be smothered by a mixture of sodium chloride and potassium carbonate.

The correct answer is: B C02 is not effective in fighting a uranium fire. All of the others are true. A uranium fire immersed in water may eventually extinguish the fire, provided enough water is present to account for water being boiled away.

Question Number: 819 Applied Radiation Protection Why should swipes in a loose-surface contamination survey be kept separate from one another? A) To avoid mislabeling the swipes B) To avoid cross-contamination C) To avoid contaminating the plastic bag D) To avoid criticality E) To reduce radwaste volume

The correct answer is: B Cross-contamination of these surface contamination samples will yield inaccurate results when counted and documented on the survey report.

Question Number: 907 Applied Radiation Protection According to the EPA, a home should be remediated if the average long term Radon concentration exceeds: A) 1 pCi/liter B) 4 pCi/liter C) 10 pCi/liter D) 50 pCi/liter E) 50% of the DAC assuming an occupancy factor of 1/5

The correct answer is: B EPA report OPA-86-004 (1986) recommends 4 pCi/liter.

Question Number: 938 Applied Radiation Protection Reference Man's air inhalation under conditions of light activity for an eight-hour period is approximately: A) 1 x 106 cc B) 1 x 107 cc C) 3 x 107 cc D) 5 x 107 cc E) 1 x 108 cc

The correct answer is: B ICRP 23 specifies Reference Man's breathing rate as about 2 x 10 4 ml/min. Therefore: (2 x 104 ml/min)(60 min/hr)(8 hr)(1 cc/ml) = 9.6 x 106 cc = approximately 1 x 10 7 cc

Question Number: 880 Applied Radiation Protection The NRC must receive immediate notification if an event involving byproduct, source, or special nuclear material possessed by the licensee may have caused or threatens to cause: A) eye dose equivalent of 0.15 Sv or more. B) total effective dose equivalent of 0.25 Sv or more. C) shallow dose equivalent of 0.25 Sv or more. D) an intake of 3 times the annual limit. E) extremity dose equivalent of 0.5 Sv or more.

The correct answer is: B Immediate notification is required for acute doses in excess of five times the annual occupational limits. 0.25 Sv = 25 rem. See 10 CFR Part 20.2202

Question Number: 868 Applied Radiation Protection Monitoring of nuclear power plant effluents during normal operations includes airborne and liquid pathways. Monitoring of liquid effluent is accomplished by which three methods? A) Base-time, grab sample, filtration processing B) Real-time, grab sample, composite sampling C) Lag-time, in-line sampling, separation sampling D) Post-time, random sampling, distillation sampling E) Lead-time, continuous sampling, vitrification sampling

The correct answer is: B In some cases, liquid effluents are monitored using all three methods. Maletskos, C.J.,Radiation Protection at Nuclear Power Plants.

Question Number: 898 Applied Radiation Protection Exemptions to leak testing sealed sources according to 10 CFR 31.5 are: 1. < 10 µCi BG 2. Kr only 3. < 1 x 10 µCi alpha 4. Tritium only 5. Not in use for > 6 months A) 1,2,3 B) 2,4 C) 2,3,4,5 D) 2,4,5 E) 1,2,5

The correct answer is: B Krypton is a gas and Tritium is a low beta emitter and is hard to measure on a smear survey. 10 CFR Part 31.5

Question Number: 986 Applied Radiation Protection Based on 10 CFR 20, a whole body dose of greater than 25 rems will require: A) notification of the NRC (or Agreement state) within 24 hours. B) notification of the NRC (or Agreement state) immediately. C) notification of the NRC (or Agreement state) within 1 business day. D) notification of the NRC (or Agreement state) and EPA prior to the worker leaving the site. E) notification of the NRC (or Agreement state) prior to the worker leaving the site.

The correct answer is: B Notwithstanding any other requirements for notification, each licensee shall immediately report any event involving byproduct, source, or special nuclear material possessed by the licensee that may have caused or threatens to cause any of the following conditions: An individual to receive: 1. A total effective dose equivalent of 25 rems (0.25 Sv) or more; or 2. A lens dose equivalent of 75 rems (0.75 Sv) or more; or 3. A shallow-dose equivalent to the skin or extremities of 250 rads (2.5 Gy) or more. These are the dosimetry conditions requiring immediate notification of the NRC per 10 CFR Part 20.2202.

Question Number: 805 Applied Radiation Protection The protection factor for an atmosphere-supplied hood which is operated at the maximum recommended flow rate with a calibrated flow gauge is which of the following? A) 10,000 B) 2,000 C) 1,000 D) 50 E) 10

The correct answer is: B Protection factors appear in 10 CFR Part 20 Appendix A .

Question Number: 903 Applied Radiation Protection Which of the following Regulatory Guides might be of use to a female employee considering declaring pregnancy? A) 1.145 B) 8.13 C) 8.25 D) 8.34 E) 8.35

The correct answer is: B Regulatory Guide 8.13 is "Instructions Concerning Prenatal Radiation Exposure".

Question Number: 864 Applied Radiation Protection Power reactors do not routinely count smears for alpha activity during general area surveys. This practice is based on: A) the amount of alpha activity in the reactor coolant system. B) the results of the alpha to beta-gamma isotopic makeup identified in the 10 CFR 61 analysis. C) the history of the plants nuclear fuel performance. D) the results of alpha-beta-gamma surveys of radioactive sources in accordance with 10 CFR 35. E) the lack of sensitive instruments to measure alpha activity.

The correct answer is: B Routine survey smears are not counted for alpha if the 10 CFR Part 61 Low level Waste Classification analysis of waste streams indicates a plant specified ratio (typical is 500:1) of beta-gamma to alpha on all waste streams.

Question Number: 822 Applied Radiation Protection Suppose a worker, over the course of a year, orally ingests 30% of the ALI and inhales 1,000 DAC-hours of 226-Ra. What is the maximum whole body external exposure this worker can receive without exceeding the ICRP 26 recommended limit? A) 0.005 Sv B) 0.01 Sv C) 0.1 Sv D) 0.05 Sv E) 0.5

The correct answer is: B Since a one ALI intake will produce .05 Sv CEDE and 2000 DAC-hours will produce .05 Sv CEDE: (.30)(.05 Sv) + [(1000/2000)(.05 Sv) = 0.04 Sv and the ICRP 26 limit is 0.05 Sv Therefore: 0.05 Sv - 0.04 Sv = 0.01 Sv

Question Number: 813 Applied Radiation Protection One DAC-hour is approximately equal to a committed effective dose equivalent of: A) 0.025 rem. B) 0.0025 rem. C) 0.25 rad. D) 0.25 rem. E) 2.5 rad.

The correct answer is: B Since the sALI is the amount of radioactive material that will produce 5000 mrem CEDE if taken into the body, and 2000 DAC hours = 1 sALI Then: (1 DAC-hour)(1 sALI/2000 DAC hours)(5000 mrem/sALI) = 2.5 mrem = .0025 rem

Question Number: 981 Applied Radiation Protection When a neutron is absorbed by an atom in shielding: A) the atom can emit a gamma ray and become radioactive. B) the atom can emit a gamma ray and may or may not become radioactive. C) the atom will undergo elastic scattering. D) the albedo energy will cause spallation in the shield. E) the albedo energy will cause fission in the shield.

The correct answer is: B Some atoms, such as hafnium, can absorb multiple neutrons without becoming radioactive. If an atom absorbs a neutron, it can emit energy (gamma ray) equal to the binding energy of the neutron, or it may also eject a particle in some cases.

Question Number: 906 Applied Radiation Protection According to ICRP publication 60, the "equivalent dose" to a tissue is the product of the absorbed dose averaged over the tissue and: A) an appropriate quality factor. B) an appropriate radiation weighting factor. C) an appropriate tissue weighting factor. D) an appropriate nonstochastic risk coefficient. E) an appropriate stochastic risk coefficient.

The correct answer is: B The 1990 recommendations have replaced the 1977 concept of quality factor with radiation weighting factor. The radiation weighting factors from ICRP 60 are as follows: RADIATION RADIATION WEIGHTING FACTOR X, gamma, beta 1 Alpha, multiple-charged particles, fission fragments, heavy particles of unknown charge 20 Neutrons of unknown energy 10 High energy protons 10

Question Number: 826 Applied Radiation Protection ICRP 26 recommends the use of a weighting factor to express the proportion of stochastic risk from an irradiated tissue, T, to the total risk when a body is uniformly irradiated. For the lung, this factor has a value of: A) 0.03 B) 0.12 C) 0.25 D) 0.30 E) 0.50

The correct answer is: B The ICRP 26 (1977) tissue weighting factors are as follows: Gonads 0.25 Breast 0.15 Red Bone Marrow 0.12 Lung 0.12 Thyroid 0.03 Bone Surfaces 0.03 Remainder 0.06 Whole body 1.00 It is important to note that the weighting factors have been revised in the 1990 recommendations of the ICRP (ICRP 60). The 1977 values are used in the 1991 revision to 10 CFR Part 20 .

Question Number: 966 Applied Radiation Protection At what point in the fuel cycle does criticality become an important consideration? A) Mining B) Milling C) Conversion D) Enrichment E) Distillation

The correct answer is: D Prior to enrichment, the U-235 content is 0.7%, and is insufficient to achieve a criticality under normal conditions.

Question Number: 824 Applied Radiation Protection ICRP 30 replaces the ICRP 2 concept of critical organ with the concept of: A) genetic region. B) target tissue. C) source region. D) organ equivalent. E) tissue region.

The correct answer is: B The committed dose equivalent limit in a year for any individual target tissue under these 1977 recommendations is 50 rem. Each target tissue is assigned a tissue weighting factor to draw a proportion of the risk of stochastic effects from irradiation of that tissue to the total risk of stochastic effects when the body is irradiated uniformly. It is important to note that tissue weighting factors have been revised in the 1990 recommendations of the ICRP (ICRP 60).

Question Number: 701 Applied Radiation Protection The major radiological health concern associated with burial of low level solid radioactive waste is: A) external radiation at the surface of the burial site. B) contamination of potable water supplies. C) airborne radioactivity resulting from contaminated soil. D) release of volatile radioactive daughter products. E) contamination of vegetables grown in soil at the site.

The correct answer is: B The critical exposure pathway for near-surface disposal of radioactive materials is through drinking water. Most of the regulations surrounding the burial of radioactive materials, such as waste classification and stabilization requirements, are designed to prevent contamination of potable (drinkable) water.

Question Number: 845 Applied Radiation Protection The ordering of the following shielding materials to provide maximum protection from a fast neutron source starting at a point closest to the source should be: A) lead, boron, plastic. B) plastic, boron, lead. C) boron, plastic, lead. D) boron, lead, plastic. E) plastic, lead, boron.

The correct answer is: B The hydrogenous plastic is used to thermalize the neutron spectrum, then the boron captures the neutrons. The lead is present to shield gammas from activation products (capture gammas).

Question Number: 842 Applied Radiation Protection A regional low-level waste compact's burial site requires all High Integrity Containers to be filled to at least 85% volume. What is the primary technical basis for this requirement? A) Self-shielding/ALARA B) Post burial water intrusion C) Reduce annual shipping costs D) Conservation of site burial costs E) Limit thermal wattage

The correct answer is: B The critical exposure pathway from a low-level radioactive waste burial site is through the water supply. The stability of the wasteform in the disposal atmosphere is an important factor in preventing release of the contents. Without a significant volume of the HIC filled, the container could collapse from overburden and release its contents.

Question Number: 968 Applied Radiation Protection The primary scatterer in an x-ray room is the: A) Buckey B) Patient C) Secondary shield D) Collimators E) Table

The correct answer is: B The patient is the primary scatter as the primary beam will "hit" (interact) first with the patient.

Question Number: 916 Applied Radiation Protection According to the revised 10 CFR 20, the quality factor for thermal neutrons is: A) 1 B) 2 C) 2.5 D) 3 E) 5

The correct answer is: B The quality factor relates absorbed dose to dose equivalent. See 10 CFR Part 20.1004

Question Number: 887 Applied Radiation Protection The Department of Energy's yearly administrative control level for Total Effective Dose Equivalent for all DOE activities as addressed in the DOE'S Radiological Control manual is: A) 1 rem. B) 2 rem. C) 0.5 rem. D) 5 rem. E) 0.1 rem.

The correct answer is: B The regulatory limit is 5 rem. (10 CFR 835.202) The administrative control level is in place to ensure ALARA and to follow the 1990 recommendations of the ICRP (ICRP Publication 60). DOE Radiological Control Manual Article 211.

Question Number: 912 Applied Radiation Protection In 10 CFR 20 the weighting factor of .3 for remainder organ includes how many organs? A) 3 B) 5 C) 6 D) 10 E) 15

The correct answer is: B There are a total of 11 organs identified. FIve are included in the "remainder". See 10 CFR Part 20 definitions section 20.1003.

Question Number: 908 Applied Radiation Protection The goal of the ICRP is setting radiation protection standards is to: A) prevent stochastic and non-stochastic effects. B) prevent non-stochastic effects and limit stochastic effects to an acceptable level of risk. C) prevent stochastic effects and limit non-stochastic effects to an acceptable level of risk. D) provide a basis to prevent litigation. E) limit genetic effects to less than 1 birth defect in 100,000 live births.

The correct answer is: B There is no way to prevent stochastic effects. Radiation doses are limited to minimize the probability of stochastic effects, such as cancer.

Question Number: 933 Applied Radiation Protection A Type A quantity of radioactive materials in a package labeled "Yellow-II" is exempt from the 10 CFR 20 radiation and contamination receipt survey requirements if it contains: A) only nuclides with half-lives < 30 days. B) only gases or special form materials. C) < 10 mCi of H-3, C-14, S-35, or I-125. D) < 10 µCi of radioactive material. E) There are no exemptions from the receipt survey requirements for labeled packages of radioactive materials.

The correct answer is: B This is an NRC regulation that applies to radioactive materials packages. 10 CFR Part 20.1906(b)

Question Number: 874 Applied Radiation Protection According to 10 CFR 19, all individuals who are employed by a company must receive instruction in the health protection problems associated with excessive exposure to radiation if they are likely to receive: A) 10 mSv. B) 1 mSv. C) 5 mSv. D) 10% of annual dose limit. E) 0.5 mSv.

The correct answer is: B This is equivalent to 100 millirem, the upper bound of allowable dose to the general public. 40 CFR Part 19.12(a)

Question Number: 850 Applied Radiation Protection Which one of the following radiological operations is MOST likely to require the use of a remote handling device? A) Oral administration of a 100 millicurie I-131 solution to a medical patient. B) Handling a PuBe source during calibration of a neutron dose equivalent rate meter. C) Eluting a dose of Tc E99m from a radioisotope generator. D) Source checking a beta-gamma contamination monitoring instrument. E) Injection of a 5 millicurie P-32 solution as sodium phosphate to a medical patient.

The correct answer is: B This operation typically involves the highest radiation dose equivalent rates of those listed. None of the distractors routinely employs remote handling devices.

Question Number: 895 Applied Radiation Protection After exposure rates from radioactive fallout (from nuclear weapons) have begun to decrease, a rough idea of future rates can be gained by using the: A) curie meter rem rule. B) 7:10 rule. C) submersion dose calculation. D) EPA PAG recommendations. E) quick sort survey.

The correct answer is: B This rule states that for every seven-fold increase in time after detonation, there is a ten-fold decrease in exposure rates. Johnson and Birky, Health Physics and Radiological Health .

Question Number: 804 Applied Radiation Protection The target material in an x-ray generating device is typically constructed of: A) aluminum. B) tungsten. C) zinc alloy. D) lead. E) uranium.

The correct answer is: B Tungsten has a high melting point to withstand the heat generated in the device, and has a high-Z to promote bremsstrahlung.

Question Number: 957 Applied Radiation Protection Neutron activation is generally NOT a problem in electron accelerators used in industry and medicine when the energy of the electrons is kept to less than: A) 5 MeV B) 8 MeV C) 10 MeV D) 30 MeV E) 50 MeV

The correct answer is: B Below this threshold, there will be very little neutron production and subsequent activation products. NCRP Report 144, pg. 23.

Question Number: 787 Applied Radiation Protection What is the appropriate method of using high-Z and low-Z shielding materials for a mixed beta-gamma source? A) High-Z followed by low-Z B) Low-Z followed by high-Z C) High-Z surrounded by low-Z D) Low-Z surrounded by high-Z E) High-Z material only

The correct answer is: B The low-Z material would be placed closest to the source to shield the beta particles, while preventing bremsstrahlung, and the high-Z material would follow to shield the gamma photons.

Question Number: 875 Applied Radiation Protection A radioactive shipment is properly prepared for transport in accordance with DPT requirements, in the truck bay of your facility. You do not need to control the area as a high radiation area as defined in 10 CFR 20 if which of the following are met? A) Package does not remain in area more than 1 hour and dose rate at 1 meter does not exceed 0.5 mSv/hr. B) Package does not remain in area more than 3 hours and dose rates at 30 cm does not exceed 10 mSv/hr. C) Package does not remain in area more than 3 days and dose rate at 1 meter does not exceed 0.1 mSv/hr. D) Package does not remain in area more than 7 days and dose rates at 30 cm does not exceed 0.5 mSv/hr. E) Package does not remain in area more than 5 working days and the dose rate at 1 meter does not exceed 1 mSv/hr.

The correct answer is: C 0.1 millisievert/hr represents the upper limit of the transport index for a package shipped non-exclusive use. Since the shipment is controlled for release to the public highway, it is determined to be adequately controlled while in storage, but only up to 3 days. 10 CFR Part 20.1601(e)

Question Number: 848 Applied Radiation Protection A locking access control system is installed at the entrance to a food irradiation cell which uses a 10,000 curie Co-60 source. In accordance with 10 CFR 20, which posting should be placed at the entrance of the cell? A) Caution - Radiation Area B) Caution - High Radiation Area C) Grave Danger - Very High Radiation Area D) Danger - Very High Radiation Area E) Danger - High Radiation Area

The correct answer is: C 10 CFR Part 20 requires this posting when the absorbed dose rate could exceed 500 rad/hr at one meter from the source or the surface that the radiation penetrates. This source unshielded would produce over 15,000 rad/hr at one meter.

Question Number: 897 Applied Radiation Protection The leakage radiation from a diagnostic x-ray assembly measured at a distance of 1 meter in any direction from the source shall not exceed: A) 1000 millirem per hour. B) 2 millirem per hour. C) 100 millirem per hour. D) 20 millirem per hour. E) 10 millirem per hour.

The correct answer is: C 100 millirem in 1 hour when the x-ray tube is operated at the leakage technique factors. This is an FDA regulation. 21 CFR Part 1020.30

Question Number: 865 Applied Radiation Protection A worker has been contaminated by a hot particle; the skin dose assigned to the worker is determined using the guidelines established by the NCRP and NRC. The area and depth the dose is calculated to is: A) 1 cm2 and 300 mg/cm2 B) 100 cm2 and 1000 mg/cm2 C) 10 cm2 and 7 mg/cm2 D) 1 mm2 and 7 mg/cm2 E) 1 mm2 and 1000 mg/cm2

The correct answer is: C 7 mg/cm2 is the density thickness value for the shallow dose equivalent. See NCRP Report No. 106, 130 and NRC IN 90-48.

Question Number: 946 Applied Radiation Protection The dose equivalent rate at the surface of a package is 180 mrem/hr. The label required for shipment is: A) Radioactive White I B) Radioactive Yellow II C) Radioactive Yellow III D) Radiation Area E) High Radiation Area

The correct answer is: C A Radioactive Yellow III label must be applied to any package of radioactive material not excepted from labeling that has a surface radiation level greater than 50 mrem/hr or a transport index greater than 1.0.

Question Number: 854 Applied Radiation Protection The "institutional monitoring period" for a low-level radioactive waste disposal site which utilizes near-surface disposal is: A) five years. B) fifty years. C) one-hundred years. D) three-hundred years. E) five-hundred years.

The correct answer is: C After closure, the site is monitored for a period of five years by the operator of the site. It is then turned over to the state for the institutional monitoring period of 100 years. After 100 years, the state may lift access restrictions on the site. These requirements are set forth in the Low Level Waste Policy Act as amended (1985) and 10 CFR Part 61 .

Question Number: 955 Applied Radiation Protection Methods for estimating radiation dose in an accident when none of the victims are wearing dosimetry include all of the following EXCEPT: A) Lymphocyte count B) Electron spin resonance of a watch crystal C) Paracyte count D) Measurements and estimation of stay times E) Activation of materials

The correct answer is: C Answer E would only be valid in a neutron flux.

Question Number: 970 Applied Radiation Protection Ar-41 is produced in a reactor: A) as a fission fragment of U-235. B) as a fission product of U-235. C) as an activation product of air. D) as a fission product of "tramp" uranium. E) as a fission product or fission fragment of U-238.

The correct answer is: C Ar-41 is activated by Ar-40 in air (naturally occurring) absorbing a neutron.

Question Number: 871 Applied Radiation Protection Liquid effluents are NOT considered: A) a significant contribution to the amount of activity released during normal operations. B) an environmental sample method. C) an accident-release pathway. D) for in-line monitoring applications. E) when calculating radioactive release to the environment.

The correct answer is: C Because of this, additional instrumentation for accident monitoring is not used. Releases of liquid effluents are normally under manual control because they involve the discharge from holdup tanks. Maletskos, C.J.,Radiation Protection at Nuclear Power Plants.

Question Number: 959 Applied Radiation Protection When using water as a beam stop, the dominant radionuclides that could possibly pose a radiological hazard are all of the following EXCEPT: A) Tritium B) Be-7 C) C-14 D) N-13 E) O-15

The correct answer is: C C-11 and not C-14 is of most concern. NCRP Report 144, pg. 25.

Question Number: 717 Applied Radiation Protection Which dosimetry should be worn in mixed neutron/beta/gamma field? A) Self-reading quartz fiber dosimeter and beta-gamma responsive TLD B) Self-reading quartz fiber dosimeter and criticality dosimeter C) Albedo TLD, self-reading quartz fiber dosimeter and beta-gamma responsive TLD D) Neutron film badge and criticality dosimeter E) Beta-gamma responsive TLD and criticality dosimeter

The correct answer is: C Choice C provides typical occupational personnel monitoring devices for the radiations listed. Criticality dosimetry is only useful in accident-magnitude situations.

Question Number: 882 Applied Radiation Protection The class designation (D, W, and Y) given in the "Class column" of Appendix B to part 20 applies only to: A) stochastic ALIs and DACs. B) airborne and effluent release to the general environment. C) inhalation ALIs and DACs. D) oral ingestion ALIs. E) releases to sewers.

The correct answer is: C Classes based on retention of an aerosol of 1 µm AMAD particles in the pulmonary region of the lung.

Question Number: 971 Applied Radiation Protection A Silver Zerolite filter is typically used to: A) purify water in the primary system. B) remove impurities from the fuel pool water, to help reduce radiation levels. C) collect iodine when performing air samples. D) increase HEPA filter service life. E) collect noble gas samples.

The correct answer is: C Collect iodine air samples, frequently in emergency scenarios, as it does not collect noble gasses.

Question Number: 801 Applied Radiation Protection In shielding sources which produce gamma rays, the exposure rate outside a shield exceeds that calculated from pure exponential attenuation (e-µx) PRIMARILY because of: A) x-rays resulting from the photoelectric interaction of primary photons in the shield. B) annihilation photons being produced by the interaction of primary photons in the shield. C) the contribution from Compton scattered gamma rays. D) bremsstrahlung. E) photoelectric absorption in the shield.

The correct answer is: C Compton scattering is the greatest contributor to the buildup factor at a point outside the shield. Buildup factor is used to correct the pure exponential attenuation equation when performing shielding calculations.

Question Number: 950 Applied Radiation Protection According to Department of Transportation regulations, Depleted Uranium is uranium that is: A) 0.7% U-235, 99.3% U-238 B) 0.7% U-238, 99.3% U-235 C) 0.45% U-235, 99.55% U-238 D) 0.4% U-238, 99.6% U-235 E) 100% U-238

The correct answer is: C Depleted Uranium has had most of the 234U and 235U removed. It is used for ordnance and shielding. See 49 CFR Part 173.435 for definition.

Question Number: 891 Applied Radiation Protection The best way to reduce the volume of waste HEPA filters is to prolong the life of those in use. One of the recommended actions is to: A) air blow filters to reduce DP across HEPA. B) reverse filter when DP is high. C) use pre-filters and replace when DP is high. D) backflow air to reduce DP. E) decrease air flow through unit.

The correct answer is: C EPRI Radwaste Desk Reference Question 1116: Prefilters, which collect debris and large particles of dust, prevent clogging of the filters. They extend the life of a HEPA by an order of magnitude.

Question Number: 799 Applied Radiation Protection An air sample is run at 2 cubic feet per minute for 70 minutes. The sample yields 3,500 net counts per minute on a counting system with a 14% efficiency. The sample activity is: A) 1.13 x 10-8 µCi/cc B) 1.99 x 10-7 µCi/cc C) 2.84 x 10-9 µCi/cc D) 4.05 x 10-8 µCi/cc E) 8.04 x 10-5 µCi/cc

The correct answer is: C For this problem, the conversion from cubic feet to cubic centimeters must be known. 1 ft3 = 2.832 x 104 cc Use the air activity calculation: C = net cpm/(vol) (efficiency) (dpm/µCi) = 3500/(2cfm * 70m * 2.832 x 10 4 cc/cf) (0.14) (2.22 x 106 dpm/µCi) = 2.84 x 10-9 µCi/cc

Question Number: 975 Applied Radiation Protection The dose limit for workers in an underground uranium mine is: A) five rems per year whole body. B) five rems per year, not to exceed 5 rems in any one year, and no more than 10 rems in 5 years. C) 4 WLM per year. D) 4 pCi/L. E) 2 rems per year.

The correct answer is: C Four Working Level Months per year is the annual limit. A working level (WL) is any combination of short-lived radon daughters (for radon-222: polonium-218, lead-214, bismuth-214, and polonium-214; and for radon-220: polonium-216, lead-212, bismuth-212, and polonium-212) in 1 liter of air that will result in the ultimate emission of 1.3 x105 MeV of potential alpha particle energy. A working level month (WLM) means an exposure to 1 working level for 170 hours (2,000 working hours per year/12 months per year=approximately 170 hours per month). Four WLM is approximately equivalent to 4 rems. See 30 CFR 57.5038

Question Number: 931 Applied Radiation Protection The iodine isotope that would deliver the largest dose to the thyroid of an individual exposed to an accidental release from a nuclear power reactor is: A) I-129 B) I-130 C) I-131 D) I-132 E) I-133

The correct answer is: C I-131 has a much longer half-life (8.05 d) than all of the isotopes listed, with the exception of I-129 (1.57E7 yr). However, I-129's fission yield (0.75% from U-235) is much lower than I-131's (2.89%). Additionally, I-131 emits a much more energetic beta (0.606 MeV) than I-129 (0.15 MeV).

Question Number: 831 Applied Radiation Protection In emergency planning, a "protective action guide" is defined as: A) the radiation level corresponding to the "Radiation Protection Guide". B) the radiation dose which should not be exceeded without careful consideration of the reasons for doing so. C) the projected dose which warrants protective action to be taken. D) the maximum radiation dose which can be received without a significant deleterious somatic effects. E) the projected levels at which every effort should be make to reduce the dose as far as possible.

The correct answer is: C If it is anticipated that the protective action guides (PAGs) will be exceeded, a protective action recommendation (PAR) such as sheltering or evacuation within certain sectors and radii will be made. PAGs are expressed in units of dose equivalent, and can be found in EPA 400 (1993).

Question Number: 791 Applied Radiation Protection After shutdown of a particle accelerator, the most induced radiation can be observed at: A) the magnet assemblies. B) the beam pipe. C) the target and beam stop. D) the RF generator. E) the ion generator.

The correct answer is: C Induced radiation in an accelerator is due to neutron activation. The most neutron production is at the target and beam stop area, from the spallation of target atoms and photoneutron production by high energy photons.

Question Number: 992 Applied Radiation Protection A naturally occurring nuclide that can typically be detected by portal monitors is: A) Pu-238 B) Tc-99m C) K-40 D) Ar-41 E) Cs-137

The correct answer is: C K-40 is the only naturally occurring nuclide listed, and it emits a gamma ray that can be detected by most portal monitors.

Question Number: 706 Applied Radiation Protection Below about 0.2 MeV, the most predominant photon interaction in lead of significance in health physics is which of the following? A) Pair production B) Compton screening C) Photoelectric effect D) Rayleigh scattering E) Thompson scattering

The correct answer is: C Photoelectric effect predominates below 200 keV, Compton effect between 200 keV and 5 MeV, and Pair production above 5 MeV.

Question Number: 869 Applied Radiation Protection The government document that specifies the noble gas concentration range for monitoring several configurations for PWRs and BWRs is: A) Regulatory Guide 8.30. B) 10 CFR 100. C) Regulatory Guide 1.97. D) 10 CFR 50. E) Regulatory Guide 1.85.

The correct answer is: C Regulatory Guide 1.97 is the document that specifies the noble gas concentration range for monitoring several configurations for PWRs and BWRs.

Question Number: 977 Applied Radiation Protection An empty Type A container used to ship some contaminated re-fueling tools is being sent back to the manufacturer. The type A container was decontaminated and is now ready to ship back. The box: A) must be sent via an exclusive use vehicle only. B) can be sent as a Yellow III shipment. C) is labeled externally as "Empty" prior to shipment. D) cannot be shipped back unless certified by the DOT as still meeting Type A criteria. E) can be shipped via common carrier with no labels.

The correct answer is: C See 49 CFR Part 173.728: A packaging which previously contained Class 7 (radioactive) materials and has been emptied of contents as far as practical, is excepted from the shipping paper and marking (except for the UN identification number marking requirement described in § 173.422(a)) requirements of the subchapter, provided that: (a) The packaging meets the requirements of § 173.421(a) (2), (3), and (5) (b) The packaging is in unimpaired condition and is securely closed so that there will be no leakage of Class 7 (radioactive) material under conditions normally incident to transportation; (c) The outer surface of any uranium or thorium in its structure is covered with an inactive sheath made of metal or some other substantial material; (d) Internal contamination does not exceed 100 times the limits in § 173.443(a); (e) Any labels previously applied in conformance with subpart E of part 172 of this subchapter are removed, obliterated, or covered and the "Empty" label prescribed in § 172.450 of this subchapter is affixed to the packaging; and (f) The packaging is prepared for shipment as specified in § 173.422.

Question Number: 812 Applied Radiation Protection A radiation user authorized under a university broad scope NRC license to use a 1 Ci PuBe source tells the RSO that the source has been removed from its storage facility and cannot be found. The RSO should: A) call the state health department for assistance. B) call the governor to give warning to residents of the state. C) call the NRC and advise user to follow emergency procedures for a lost source. D) call the nearest RAP team for assistance. E) convene the Radiation Safety Committee to decide appropriate action.

The correct answer is: C Since Pu-Be contains special nuclear material, 24-hour notification to the NRC is required under 10 CFR Part 70 .

Question Number: 841 Applied Radiation Protection In general, the most important source of occupational radiation exposure at nuclear power plants is: A) gamma radiation from the core. B) long-lived fission product activity. C) neutron activation product activity. D) short-lived fission product activity. E) neutron radiation from the core.

The correct answer is: C Since activation products (most notably Co-60) are present for the life of the plant, rather than just during operation, they contribute the most to occupational radiation exposure. Work on plant components during shutdown often involves exposure to these activation products.

Question Number: 711 Applied Radiation Protection Which of the following is the MOST desirable method to provide radiological protection during maintenance on a highly contaminated component? A) Ensure workers wear protective clothing and respirators. B) Always use auxiliary ventilation. C) Attempt to remove contamination prior to maintenance. D) Ensure workers are properly trained in maintenance. E) Cover any exposed skin surfaces on workers.

The correct answer is: C Source removal or reduction should always be the first consideration when work around hazardous materials is required.

Question Number: 948 Applied Radiation Protection Based on the following DOT/NRC "A" values for the normal form of each isotope, which isotope is considered to exhibit the highest radiotoxicity? A) Co-60, 10.8 Ci B) Cs-137, 13.5 Ci C) Cf-252, 0.027 Ci D) C-14, 54.1 Ci E) Cm-242, 0.27 Ci

The correct answer is: C The "A" value represents the maximum quantity of a particular radionuclide that may be shipped in a Type A container. Quantities exceeding this value must generally be shipped in a Type B container. The lower the "A" value, the higher the radiotoxicity.

Question Number: 984 Applied Radiation Protection The percent resolution of an NaI detector with a 662 keV photopeak that is 33 keV wide at half the maximum height is: A) 0.05% B) 0.5% C) 5% D) 20.06% E) 0.2006%

The correct answer is: C The FWHM is 33 keV, and 33/662 keV then multiplied by 100 yields percent resolution.

Question Number: 999 Applied Radiation Protection A worker wearing an air purifying half face mask is in an atmosphere of 4 DAC of I-131 for 30 minutes. The estimated dose to the individual would be: A) 0.5 mrem B) 2.5 mrem C) 5 mrem D) 0.05 mrem E) 0.25 mrem

The correct answer is: C The air purifying half mask has a protection factor of 10 for particulates, but I-131 is not a particulate, so it provides no protection and does not reduce the dose. A DAC = 2.5 mrem/hr, so 4 DAC for 0.5 hours, yields 5 mrem. 4 DAC * 2.5 mrem/hr/DAC * 0.5 hr = 5 mrem

Question Number: 941 Applied Radiation Protection The term "Reference Man" in health physics is: A) the mathematically correct human being with organs which are defined by spheroids and ellipsoids to make a technically correct body for dosimetry evaluations. B) the phantom which is used to reference a body counter to a standard. C) a set of agreed upon values for the many characteristics of the human body which are needed for internal dose evaluations. D) a man of large stature to ensure conservative interpretation of dose to any individual. E) a set of agreed upon values for exposure times and rates that the normal human could tolerate.

The correct answer is: C The anatomical characteristics of Reference Man are listed in ICRP Publication 23 and in ICRP 89.

Question Number: 785 Applied Radiation Protection The dose buildup factor is 5 at the particular shielded location. What percentage of the exposure rate is due to primary (unscattered) photons? A) 5% B) 10% C) 20% D) 80% E) 95%

The correct answer is: C The buildup factor is the ratio of all photons at a point outside a shield to primary photons at that point. If the ratio is 5:1, then the primary photons comprise 1/5, or 20%, of the exposure rate.

Question Number: 846 Applied Radiation Protection What is the cadmium absorption edge? A) The energy level at which the neutron capture cross-section of cadmium shows a steep increase. B) The energy level at which the electron capture cross-section of cadmium shows a steep increase. C) The energy level at which the neutron capture cross-section of cadmium shows a steep decrease. D) The energy level at which the electron capture cross-section of cadmium shows a steep decrease. E) The energy level at which the photon absorption cross-section of cadmium shows a steep decrease.

The correct answer is: C The cadmium absorption edge occurs at about 0.2 MeV.

Question Number: 960 Applied Radiation Protection Klystron tubes used to generate RF accelerating fields for accelerators: A) are not a major radiological concern, but a magnatron would be a concern. B) are strictly an RF hazard, and as such, should always be checked to verify that the SAR limits are not exceeded. C) should be checked for x-ray production and leakage, especially in the region around the RF output waveguides and beam collimator cooling connections. D) produce x-rays in predictable, reliable patterns, such that an initial installation survey is necessary, and subsequent surveys are only required when the unit is either moved or upgraded. E) generate x-rays when a vacuum is present, and the number of x-rays will gradually go down as vacuum is lost.

The correct answer is: C The converse of answers A and E are true. NCRP Report 144, pg. 25-26.

Question Number: 860 Applied Radiation Protection Radiation leakage from an x-ray tube is higher in energy than that of the primary radiation beam. This difference in energy level is due to: A) the proximity of the leakage location to the origin of the x-rays. B) acceleration of the leakage x-rays by the tube voltage. C) the filtering of the primary beam as it passes through the tube housing. D) the interaction of the x-rays with the tube housing. E) the interaction of the x-rays with the magnetic fields generated in the tube.

The correct answer is: C The leakage radiation is filtered and "hardened" in traversing the tube housing - typically high-Z shielding material. The primary beam is filtered only with a thin low-Z filter, allowing more lower energy photons to escape without interaction. NCRP Report 147.

Question Number: 757 Applied Radiation Protection The maximum allowable radiation level at one meter from the surface of a package shipped in other than an exclusive use vehicle is which of the following? A) 1 mrem/hr B) 2.5 mrem/hr C) 10 mrem/hr D) 100 mrem/hr E) 200 mrem/hr

The correct answer is: C The maximum allowable Transport Index for a package shipped non-exclusive use is 10.0, which represents 10 mrem/hr at one meter.

Question Number: 809 Applied Radiation Protection Reactor chemistry samples are often treated with nitric acid to: A) remove interference from volatiles. B) preserve the sample for future analysis. C) destroy organics. D) prevent cross-contamination. E) aid isotopic separation.

The correct answer is: C The nitric acid helps metals in the sample to remain in solution for analysis at a later date.

Question Number: 944 Applied Radiation Protection In the transportation of radioactive materials, the PRIMARY means of achieving safety is: A) effective use of time, distance, and shielding by everyone involved. B) restricting transport to times of low traffic density. C) proper approved packaging for the contents. D) use of placards and labels that contain warnings. E) proper procedures to prevent damage from rough handling.

The correct answer is: C The package is the primary engineering barrier between the hazardous material and personnel. Packaging is designed to withstand various degrees of transportation conditions. Type A packaging is designed to withstand normal conditions of transport. Type B packaging is designed to withstand hypothetical accident conditions.

Question Number: 993 Applied Radiation Protection ) A uranium mill must monitor workers dose: A) in case of a criticality. B) from Co-60, Cs-137 and other fission products. C) for radon. D) for Ar-41. E) for both A and B

The correct answer is: C The uranium mill only has natural uranium present within the ore, so there is no criticality hazard, and no fission products are present. Ar-41 requires a neutron flux, which is not present. The radon originates from the radium found (typically) in equilibrium with the uranium.

Question Number: 811 Applied Radiation Protection When sampling for radioactive fallout, the nuclides of concern in cow feed, milk, grazing vegetation, and manure are: A) Pu-230 and Cs-137 B) Sr-90 and Pu-239 C) Sr-90 and Cs-137 D) Cs-137 and Am-241 E) Sr-90 and Am-241

The correct answer is: C These long-lived fission products are good indicators of the extent of fission releases to the atmosphere. Each of these decay by beta, and have an affinity for cereals and grains. The shorter-lived fission products are less useful in the assessment of population dose, although their contribution to the dose is important.

Question Number: 755 Applied Radiation Protection A respirator containing a high efficiency particulate filter offers adequate protection for all of the following EXCEPT: A) Radon and thoron daughters B) Xenon and krypton daughters C) Radon and iodine D) Uranium dust E) Nuisance dusts

The correct answer is: C These are the only gases that appear as choices. Daughters of Rn, thoron, Xe, and Kr are particulates.

Question Number: 800 Applied Radiation Protection In a medical hospital using radioisotopes for diagnostic and therapeutic purposes, what limits are placed on the discharge of patient excreta into the sanitary sewer system? A) No limit if the patient doses are less than 1 mCi each B) Activity totaling 1 curie per year may be discharged C) No limitation D) Limited only by the amount of dilution water in the sewer to 1 x 10 -5 µCi/cc gross activity E) Total activity which may be discharged per quarter is 1.25 curies

The correct answer is: C These limits are set forth in 10 CFR Part 20. As excreta, there is no limitation. There may be 1 curie total per year disposed in the sewer per facility (non-excreta), with an additional allowable 5 Ci H-3 and 1 Ci C-14.

Question Number: 902 Applied Radiation Protection An accessible area as defined by the NRC for the purpose of posting radiological areas is any area: A) where any part of the body can be exposed to radiation. B) where any part of the whole body can be exposed. C) that can be reasonably occupied by a major portion of the whole body. D) where personnel can have access through deliberate or inadvertent action which may lead to radiation exposure. E) capable of human habitation.

The correct answer is: C This comes from Reg. Guide 8.38, Page 2.

Question Number: 856 Applied Radiation Protection After a criticality accident, an individual's exposure to neutrons can be measured by placing a gamma detecting survey instrument probe over the abdomen and doubling the individual over the probe. A reading of 0.1 millirem per hour on a GM probe indicates an absorbed neutron dose of: A) 5 rem. B) 10 rads. C) 15 rads. D) 25 rem. E) 30 rads.

The correct answer is: C This technique should be followed by more accurate measurements on blood and urine samples for Na-24 or hair samples for P-32. Metal objects on an individual should also be measured for induced radioactivity if neutron exposure has occurred. (NCRP 65, page 29)

Question Number: 918 Applied Radiation Protection For every short lived radionuclides (< 2 hours) suspended in air, the external dose may exceed the internal dose by a factor of: A) 1 - 1,000 B) 1 - 100 C) 1 - 10 D) 1 E) > 1

The correct answer is: C This value comes from Appendix B footnotes of 10 CFR Part 20.

Question Number: 855 Applied Radiation Protection The radionuclide used to improve optical instrument performance through improved light processing by the lens is which of the following? A) Neptunium B) Uranium C) Thorium D) Tritium E) Cesium

The correct answer is: C Thorium is added to optical instrument glass in concentrations up to 30% by weight to provide certain optical properties.

Question Number: 920 Applied Radiation Protection The internal hazard from uranium at an enrichment facility is in general: A) constant regardless of enrichment. B) based only on chemical toxicity. C) based on chemical toxicity at low enrichments and radiation effects at higher enrichments. D) based only on radiation effects at low enrichments and criticality at higher enrichments. E) based on radiation effects at low enrichments and chemical toxicity at higher enrichments.

The correct answer is: C Uranium is primarily a chemical toxicity hazard until concentration produces a criticality hazard.

Question Number: 979 Applied Radiation Protection According to 10 CFR 20 extremity dosimetry is needed when: A) a large dose is expected to the hands, feet or upper arms. B) a large dose is expected to the hands, feet, upper arms or head. C) the dose to the extremities is anticipated to exceed 10% of the extremity limits. D) the dose to the head, feet, hands, or upper arms will exceed 10% of the extremity limits. E) doses are greater than the head, neck, upper arms, hands and feet require to exceed stochastic limits established by the NRC in appendix B of 10 CFR 20.

The correct answer is: C When 10% of the extremity limits of 50 rems is expected, then extremity dosimetry is required.

Question Number: 982 Applied Radiation Protection Pregnant radiation worker doses are limited to: A) less than 500 mrem per year. B) less than 100 mrem per month. C) less than 500 mrem per 9 months D) less than 50 mrem per 9 months. E) less than 10% of the public dose to the fetus, since the child is not a trained worker.

The correct answer is: C The licensee shall ensure that the dose equivalent to the embryo/fetus during the entire pregnancy, due to the occupational exposure of a declared pregnant woman, does not exceed 0.5 rem (5 mSv). See 10 CFR Part 20.1208

Question Number: 929 Applied Radiation Protection A female radiation worker declares to her supervisor that she is pregnant. It is determined that the embryo/fetus has already received 700 mrem at the time the worker declares her pregnancy. According to 10 CFR 20, how much additional dose equivalent may the embryo/fetus receive during the remainder of the pregnancy? A) No additional dose equivalent is allowed. B) 300 mrem C) 4.3 rem D) 50 mrem E) 550 mrem

The correct answer is: D 10 CFR Part 20 limits the dose to an embryo/fetus to 500 mrem for the entire gestation period. 10 CFR Part 20.1208 allows an additional 50 mrem dose equivalent to the embryo/fetus for the remainder of the pregnancy if the embryo/fetus has received more than 450 mrem at the time of the declaration of pregnancy. Keep in mind that the female worker must still not exceed her annual dose equivalent limits.

Question Number: 947 Applied Radiation Protection For an exclusive use, closed transport shipment of a radioactive materials package, at what level does external package removable beta/gamma contamination become unacceptable upon arrival at the consignee's facility? A) 10-6 µCi /cm2 B) 10-5 µCi /cm2 C) 10-4 µCi /cm2 D) 10-3 µCi /cm2 E) 10-2 µCi /cm2

The correct answer is: D 49 CFR Part 173 allows package removable surface contamination levels of up to 100 times the normal limits upon arrival at the consignee's location if the package is transported exclusive use, closed transport.

Question Number: 913 Applied Radiation Protection According to NUREG-0713, which of the following occupations has the highest average annual individual dose? A) Commercial nuclear power B) Manufacturing and distribution of radioactive materials C) Low-level waste disposal D) Industrial Radiography E) Nuclear fuel fabrication

The correct answer is: D According to NUREG-0713, the average dose per worker is 540 mrem for industrial radiography.

Question Number: 942 Applied Radiation Protection A full-face respirator with HEPA filters is always recommended for typical reactor noble gas atmospheres because: A) the radioactive noble gas progeny must be filtered out. B) the beta dose to the lens of the eye will be greatly reduced. C) the probability of a skin contamination will be minimized. D) this type of full face respirator is not recommended for noble gas atmospheres. E) this type of respirator offers the highest protection factor in noble gas atmospheres.

The correct answer is: D An air-purifying respirator will not provide protection against noble gases, only their particulate progeny. Radioactive noble gases tend to be most limiting from an external exposure standpoint.

Question Number: 919 Applied Radiation Protection You work at a nuclear power plant, it is the evening shift and you are approached by an NRC inspector who wants to know the density thickness of paper protective clothing he observed on a worker. He would like the information by the end of the shift. Choose the best response. A) Politely tell the inspector that he will have to wait until you call the manufacturer tomorrow. B) Call site Security and tell them you think you smelled alcohol on the inspector's breath. C) Call the company ombudsman at home and ask what you should do. D) Cut out a square piece of material, send it to the chemistry lab to be weighed and divide the weight by the area of the material. Obtain a beta source of known activity and energy, count the source without shielding, then insert pieces of E) protective clothing material between the source and the detector until the counts fall off to background. Divide the maximum range, in mg/cm , of the beta source by the number of layers of protective clothing needed to totally shield the source.

The correct answer is: D Answer B is more fun and answer E is more work. The answer in D will yield units of g/cm density thickness. 2 or mg/cm2 which is

Question Number: 973 Applied Radiation Protection A university researcher is considering using liquid P-32 in her studies, with a possibility of some spills. What would be the best shielding to protect the researcher from the P-32 emissions? A) A thin layer of lead (~ 1/8 inch) B) A thin layer of plastic (~ 1/8 inch) C) A thin layer of borated plastic (~ 1/8 inch) D) A thick layer of plastic (2 cm) E) A thick layer of borated plastic (2 cm)

The correct answer is: D Answer D is the best answer: A thick layer (2 cm) of plastic, as it is easy to clean and will completely block the 1.71 MeV maximum energy beta. Borated is unnecessary, since no neutrons are expected.

Question Number: 743 Applied Radiation Protection The units used to express µ/ ρ (mu over rho) are: A) 1/cm B) g/cm2 C) g/cm3 D) cm2/g E) cm3/g

The correct answer is: D Attenuation coefficient is represented by µ in units of cm -1. Density is represented by ρ in units of (g)(cm -3). So: µ/ρ = cm-1/(g)(cm-3) = cm2/g

Question Number: 951 Applied Radiation Protection The National Academy of Sciences report that details the most recent recommendations on exposure to radon, and includes the latest models is which of the following? A) BEIR III B) BEIR IV C) BEIR V D) BEIR VI E) BEIR VII

The correct answer is: D BEIR VI is entitled, "The Health Effects of Exposure to Indoor Radon," 1999, whereas, BEIR IV is entitled, "Health Risks of Radon and other Internally Deposited Alpha Emitters," 1988.

Question Number: 770 Applied Radiation Protection A 500 millicurie Phosphorous-32 solution has spilled in a hospital room. A quick method of shielding the spill and preventing the spread of contamination would be to: A) open the window to completely ventilate the room. B) increase the building ventilation flow to dilute the solution throughout the building. C) use a broom to consolidate the spill and cover with towels. D) cover the spill with a plastic bedsheet. E) hose down the room and direct the spill to the floor drain system.

The correct answer is: D Choices C and D are the only choices which include a shielding consideration. Since P-32 is a 1.7 MeV Emax "pure beta-emitter", plastic is an appropriate shield. A broom should never be used to perform surface decontamination due to the potential for airborne radioactivity.

Question Number: 969 Applied Radiation Protection A laser used to align piping in a facility is typically a: A) Class A laser. B) Class B laser. C) Class 4 laser. D) Class 3R or lower. E) Class R laser.

The correct answer is: D Class 3R lasers are designed so that "aversion response" (moving your eye when you see the laser) should be sufficient to protect your eyes. Class 1 and 2 are also typical lasers that do not usually require eye protection when used.

Question Number: 835 Applied Radiation Protection The radionuclide that is the main cause of shutdown radiation fields at nuclear power plants is: A) N-16 B) Cs-137 C) Co-58 D) Co-60 E) Xe-135

The correct answer is: D Co-60 is an activation product from the activation of Co-59 and the activation of iron. Co-59 is present in nuclear power plants in valve seats and control rod blade roller pins. Iron, of course, is an important component of stainless steel. Co-60 decays by beta, with a 1.17 and a 1.33 MeV gamma. It has a 5.27 year half-life.

Question Number: 816 Applied Radiation Protection The protection factor provided by a self-contained breathing apparatus in the pressure-demand mode is which of the following? A) 10 B) 50 C) 1,000 D) 10,000 E) 20,000

The correct answer is: D In the demand mode, the PF for SCBA is only 100. Respiratory protection factors appear in 10 CFR Part 20 Appendix A .

Question Number: 838 Applied Radiation Protection In general, for a hot particle on the skin, the principal contributor to the dose to the skin in the vicinity of the particle is the: A) neutron radiation emitted from the particle. B) gamma radiation emitted from the particle. C) alpha radiation emitted from the particle. D) beta radiation emitted from the particle. E) conversion electron emitted from the particle.

The correct answer is: D Hot particles are typically small pieces of activated metal or, in some cases, fuel fragments. In power reactors they are more often than not composed of Co-60. It is the beta particles which produce the most skin dose, since the probability of interaction is much higher than for gammas.

Question Number: 839 Applied Radiation Protection Prior to 1988, explicit recommendations on limits for radiation exposure of skin by hot particles were provided by: A) the ICRP, but not the NCRP. B) both the NCRP and the ICRP. C) the NCRP but not the ICRP. D) neither the NCRP nor the ICRP. E) the ICRU, NCRP, and ICRP.

The correct answer is: D Hot particles did not receive much attention until the mid-1980's, most likely because of improvements in detection methods. Exposures were common enough that the NCRP issued Report No. 106 on hot particle exposures in 1989 and another report in NCRP 130..

Question Number: 823 Applied Radiation Protection Strict adherence to ICRP Publication 26 would allow: A) plutonium internal doses to be regulated using annual dose equivalent rather than committed dose equivalent. B) deletion of record keeping for internal doses less than 50% of the allowable dose limit. C) consideration of internal and external dose limits separately. D) use of air samples and stay-time calculations instead of respirator usage, if it is deemed to be ALARA. E) the worker to choose the type of respiratory protection device if use is required.

The correct answer is: D ICRP 26 (1977) introduced the total dose concept, rather than treating internal and external exposures differently. Keeping the total dose ALARA, be it from external or internal sources, is consistent with these recommendations.

Question Number: 736 Applied Radiation Protection In a linear accelerator, the most induced radiation will be observed: A) along the beam pipe. B) in the magnets. C) at the beam dump. D) at the target. E) in the air surrounding the target.

The correct answer is: D Induced radiation in an accelerator refers to neutron activation products. The most neutron production in a linear accelerator is at the target, where spallation of target atoms results in the release of neutrons. When thermal energies are reached by these neutrons, they are captured, creating activation products.

Question Number: 936 Applied Radiation Protection N-13, Ar-41, Kr-87, Kr-89, Xe-135, and Xe-137 are gaseous radioactive wastes resulting from which one of the following phases of the nuclear fuel cycle? A) Mining and milling B) Refining C) Fuel fabrication D) Reactor operation E) Chemical processing

The correct answer is: D N-13 and Ar-41 are air activation products. The kryptons and xenons are fission products. Of all choices, only reactor operation includes these short-lived fission products.

Question Number: 932 Applied Radiation Protection 10 CFR 20 requires a Radiation Area to be posted if: A) the dose rate at 1 meter from the source of radiation exceeds 5 mrem/hr. B) an individual could exceed a dose equivalent in excess of 5 mrem in 1 hour or 100 mrem in 5 days. C) an individual could exceed a dose equivalent in excess of 5 mrem in 1 hour at 1 meter from the source of radiation. D) an individual could exceed a dose equivalent in excess of 5 mrem in 1 hour at 30 cm from the source of radiation. E) the dose rate at 30 cm from the source of radiation exceeds 5 mrem/hour.

The correct answer is: D Note that 5 mrem in one hour may not be equivalent to a rate of 5 mrem/hour if the source is only briefly exposed. 10 CFR Part 20.1003

Question Number: 827 Applied Radiation Protection ICRP Publication 26 states, "No practice shall be adopted unless its introduction produces a net benefit." This concept is called which of the following? A) Optimization B) Maximization C) Minimization D) Justification E) Realization

The correct answer is: D Once a practice involving radiation exposure has been justified as described, the process of optimization is implemented to determine an appropriate level of radiation protection. Cost-Benefit Analysis in radiation protection is addressed in ICRP Publication 37.

Question Number: 963 Applied Radiation Protection Lasers consist of which of the following three main components? A) Mirrors, power supply, crystal B) Two mirrors and crystal C) Mirror, crystal, flashlamp D) Optical cavity, lasing medium, energy pump E) Optical cavity, energy absorbing medium, energy supply

The correct answer is: D Optical cavity consists of mirrors, or mirror like surfaces, the lasing medium can be almost any material (glass, crystal, gas, liquid), and an energy pump to provide an inversion.

Question Number: 807 Applied Radiation Protection A shield has to be constructed in front of a hot spot to reduce the exposure rate by 80%. The half value layer for the shielding is one-quarter inch. What is the minimum number of shielding thicknesses required? A) 0.5 B) 1 C) 2 D) 3 E) 4

The correct answer is: D Since HVLs are given, use I = Io (1/2)n And let Io = 1 1 - 0.8 = 1 (1/2) n 0.2 = (1/2)n log(0.2)= n * log(1/2) 2.32 = n

Question Number: 998 Applied Radiation Protection A pipe 20 feet long is producing a dose rate of 100 mrem/hr at a distance of 8 feet away. Workers must be 4 feet away for a period of 2 hours. What is the expected dose from this job? A) 100 mrem B) 200 mrem C) 300 mrem D) 400 mrem E) 500 mrem

The correct answer is: D Since the measurement and the workers are closer than L/2 (20'/2=10') the dose rate decreases linearly with distance, rather than following the inverse square law, since this is considered a line source. The dose rate at 4 feet away would be double that at 8 feet (not 4 times as with a point source), so it is 200 mrem/hr. Multiply this by 2, to get 400 mrem.

Question Number: 988 Applied Radiation Protection Special form materials typically: A) are only shipped in locked containers. B) must be shipped in Type A containers that are locked. C) produce lethal doses at 1 meter. D) are sealed sources. E) are only shipped in "special" type B containers with impact limiters.

The correct answer is: D Special form is defined in 49 CFR Part 173.403. Special form Class 7 (radioactive) material means either an indispersible solid radioactive material or a sealed capsule containing radioactive material which satisfies the following conditions: 1. It is either a single solid piece or a sealed capsule containing radioactive material that can be opened only by destroying the capsule; 2. The piece or capsule has at least one dimension not less than 5 mm (0.2 in); and 3. It satisfies the test requirements of § 173.469.

Question Number: 935 Applied Radiation Protection When working with liquid solutions containing radioactivity, all of the following are appropriate for contamination control EXCEPT: A) In order to assure ease of cleanup, surfaces in the area should be made of materials that are easily cleaned. B) Sinks and drains for radioactive liquid should be provided. C) Holding and sampling tanks should be used to prevent the release of liquids with high concentrations of radioactivity. D) Spills should be cleaned up using absorbent material and cleaning from the center of the spill to its periphery. E) Processing or other removal systems should be used to the maximum extent practical.

The correct answer is: D Spills should be cleaned starting at the outer edges and moving toward the center. All other choices are valid contamination control practices.

Question Number: 806 Applied Radiation Protection In a medical facility which uses Technecium-99m for diagnostic evaluation, the largest amount of dose is received by the technician while: A) administering the desired quantity to the patient. B) calibrating the amount of material. C) disposing of radioactive byproduct waste. D) eluting the generator. E) exposed to Technecium-99m daughter products.

The correct answer is: D Tc-99m is produced by the decay of Mo-99. When a quantity of Tc-99m is desired, the technician elutes the generator which contains the Mo-99 and the Tc-99m. The Tc-99m is soluble and is removed in saline solution. This process is also termed "milking the cow".

Question Number: 729 Applied Radiation Protection Which of the following contributes MOST to exposure rates on the turbine floor of an operating BWR plant? A) Cobalt-60 B) Cesium-137 C) Krypton-88 D) Nitrogen-16 E) Iodine-131

The correct answer is: D The BWR has primary steam in the turbine, whereas the PWR design does not. N-16 is produced from the (n,p) reaction on O-16, which is plentiful in the reactor coolant (H 2O). N-16 has a 7.1 second half-life and emits 6.1 and 7.1 MeV gamma photons.

Question Number: 889 Applied Radiation Protection A DOE radiation worker has a lifetime exposure that exceeds her age. In accordance with the DOE Radiological Control Manual, the workers exposure for the year shall be limited to: A) 2 mSv B) 1 mSv C) 5 mSv D) 20 mSv E) 10 mSv

The correct answer is: E 1 Rem is the limit convert to mSv. 1 Sv = 100 Rem

Question Number: 909 Applied Radiation Protection A shipment of radioactive materials over public highways containing a Type B package would be regulated by: A) the NRC. B) the DOT. C) the EPA. D) both the NRC and DOT. E) both the NRC and EPA.

The correct answer is: D The NRC regulates the package under 10 CFR Part 71 and the DOT regulates the shipment under 49 CFR Part 171-179.

Question Number: 771 Applied Radiation Protection The transport index is determined at: A) contact. B) one foot. C) three feet. D) one meter. E) two meter.

The correct answer is: D The Transport Index is the dimensionless number which represents the number of mrem at one meter from the surface of a radioactive materials package to be transported. It is always expressed as one place to the right of the decimal point, e.g. 1.0.

Question Number: 965 Applied Radiation Protection A Class 4 laser: A) is not a hazard under normal operating conditions. B) assumes that a laser is visible and that a person will avert their eyes in 0.25 seconds. C) is an eye hazard. D) is an eye, skin and fire hazard. E) is only a fiber optic hazard.

The correct answer is: D The actual class descriptions correspond to the numbers, with the exception of E, which does not exist. See ANSI Z136.1 section 3.

Question Number: 914 Applied Radiation Protection When is summation of external and internal doses required by 10 CFR 20? A) If external monitoring is required B) If internal monitoring is required C) If 10% of both the internal and external dose limits have been exceeded by the end of the year based on whole body counts and TLD readings D) If it is likely that individuals will exceed 10% of both the applicable internal and external limits E) If the internal hazards are present in excess of 10 times the ALI and external hazards are present and capable of exceeding 10 times the annual limit in one hour

The correct answer is: D The assessment of summation should be done prior to exposure, not after the fact based on whole body counts and TLD readings.

Question Number: 943 Applied Radiation Protection According to 10 CFR 20 Appendix A, a positive pressure, full face, air-purifying respirator has a maximum protection factor for particulates of: A) 10 B) 50 C) 100 D) 1,000 E) 2,000

The correct answer is: D The full-face, positive pressure, air-purifying respirator is assigned a protection factor of 1,000 for particulate radionuclides. See 10 CFR Part 20 Appendix A.

Question Number: 885 Applied Radiation Protection The concentration values given in Table 2 Effluent Concentrations in Appendix B of 10 CFR 20 are equivalent to the radionuclide concentrations which, if inhaled or ingested continuously over the course of a year, would produce a total effective dose equivalent of: A) 0.1 mSv. B) 5 mSv. C) 1 mSv. D) 0.5 mSv. E) 2 mSv.

The correct answer is: D The limits for air and liquid effluents when added together, would result in 1.0 mSv (100 mrem), which is the NRC'S annual limit for the general public. 10 CFR Part 20 Appendix B

Question Number: 847 Applied Radiation Protection Which of the following statements about fume hoods is INCORRECT? A) The inside of the hood and the ducts should be as easy to clean as practicable. B) The air flow should be sufficient to prevent the escape of hood air to the workplace. C) The design should provide for smooth air flow, without significant eddies. D) The gas, water, and electrical appliances should be operated from inside the fume hood. E) The exhaust fan should be placed downstream of the filters.

The correct answer is: D The operator should not have to adjust these hood functions from the inside of the hood, due to the presence of a hazardous atmosphere in the hood. This would be particularly true during an unanticipated release inside of the hood or if the hood failed. All other distractors are valid.

Question Number: 815 Applied Radiation Protection Which of the following materials will yield the greatest amount of bremsstrahlung radiation when irradiated with electrons of the same energy and intensity? A) Beryllium B) Aluminum C) Tungsten D) Uranium E) Lead

The correct answer is: D The probability of bremsstrahlung increases with the atomic number of the material. Of the materials listed, uranium has the highest atomic number.

Question Number: 843 Applied Radiation Protection When communicating information regarding a radiation accident to the general public, which of the following approaches is MOST effective? A) Avoid embarrassment by reducing the actual impact of the event. B) Let the media interpret and disseminate the pertinent information. C) Emphasis should be placed on influencing the public's actions, rather than informing the public. D) Dissemination of public information must reflect openness, correctness, and candor. E) Circumvent criticism by revealing only the most innocuous factors related to the event.

The correct answer is: D The public information officer must establish the trust of the public. Communication should be frequent, in addition to the other factors listed.

Question Number: 896 Applied Radiation Protection Radiation exposure rates produced by a television receiver from any external surface shall not exceed: A) 0.5 millirem per hour at 30 cm. B) 1 millirem per hour at 1 m. C) 2 millirem per hour at 30 cm. D) 0.5 millirem per hour at 5 cm. E) 0.1 millirem per hour at 5 cm.

The correct answer is: D The radiation is from bremmstrahlung in the flyback transformer in the cathode ray tube. 21 CFR Part 1020.10

Question Number: 952 Applied Radiation Protection In the United States there is a plant in Metropolis Illinois that is involved in the conversion to UF 6. This is a chemical process. What step follows conversion to UF 6 in the fuel cycle? A) Fuel Fabrication B) Milling C) Re-Conversion to UF6 solid (yellowcake) D) Enrichment E) Re-constitution

The correct answer is: D The steps are mining, milling, conversion, enrichment, fuel fabrication. Gollnick, Basic Radiation Protection Technology.

Question Number: 905 Applied Radiation Protection Which of the following is NOT true concerning the handling of radioiodine? A) Work in a well ventilated room. B) Wear two pairs of rubber gloves because radioiodine can diffuse through rubber and plastic. C) Keep vials containing radioiodine closed when not in use to reduce airborne radioactivity. D) Decontaminate spills with a low PH solution. E) Airborne iodine exists as elemental iodine, organic iodine, and iodine absorbed on aerosols.

The correct answer is: D The volatility of I -125 is enhanced at low a PH. Decontamination of spills should use a .1 M NaI, .1 M NaOH, and .1 M Na2S203 to stabilize the material.

Question Number: 820 Applied Radiation Protection The maximum allowable exposure rate at contact of any external surface of an exclusive use vehicle transporting radioactive materials is: A) 1 mR/hr B) 5 mR/hr C) 100 mR/hr D) 200 mR/hr E) 1000 mR/hr

The correct answer is: D These apply to exclusive use shipments only. The external contact dose rates apply to the four sides, top, and underside of the vehicle. The limit in normally occupied spaces of the vehicle is 2 mR/hr. The limit at 2 meters from the sides of the vehicle is 10 mR/hr.

Question Number: 803 Applied Radiation Protection Radioactive liquids may be transported via public highway, provided that: A) radioactive liquids may NOT be transported over public highway. B) the liquid is contained within Type B packaging. C) the liquid is labeled "Yellow III" and is contained in a DOT Spec 7A Type A packaging. D) the package is marked, "This End Up" and twice the amount of absorbent material required to absorb the liquid is in the package. E) the package includes a sealed glass liner and is marked, "Fragile".

The correct answer is: D These requirements appear in 49 CFR Part 173. Do not confuse free-standing water restrictions on radioactive wasteforms with transportation requirements for radioactive liquids.

Question Number: 878 Applied Radiation Protection You have received a package containing radioactive material. The highest smearable beta-gamma contamination on the external surface of the package is 3,000 dpm/100 cm2. You should notify: A) all individuals who handled the package and the NRC Alert team. B) the shipper and the NRC Washington office of Radioactive Material Shipping. C) the originating activity and the NRC Regional office. D) the final carrier and the NRC Regional office. E) the addressee of the package and the originating activity.

The correct answer is: D This exceeds the limit of 22 dpm/cm2. 10 CFR Part 20.1900

Question Number: 872 Applied Radiation Protection The Code of Federal Regulations, 40 CFR 190, requires that nuclear power plants maintain the dose to the maximally exposed member of the public to less than: A) 1 mSv/yr. B) 0.5 mSv/yr. C) 0.1 mSv/yr. D) 0.25 mSv/yr. E) 5 mSv/yr.

The correct answer is: D This limit, promulgated by the EPA, applies to allowable dose to the public from decommissioned facilities. 40 CFR Part 190

Question Number: 808 Applied Radiation Protection The FDA has recommended potassium iodide as a thyroid-blocking agent when doses to the thyroid are anticipated to be in excess of: A) 0.5 rem. B) 1 rem. C) 5 rem. D) 25 rem. E) 75 rem.

The correct answer is: D This recommendation comes from the FDA publication, "Potassium Iodide as a Thyroid-Blocking Agent in a Radiation Emergency: Final Recommendations on Use", June, 1982.

Question Number: 930 Applied Radiation Protection Which of the following is the 10 CFR 20 definition of a Very High Radiation Area (VHRA)? An area, accessible to individuals, in which the radiation levels could result in an individual receiving an absorbed A) dose in excess of 50 rads (0.5 grays) in 1 hour at 1 meter from a radiation source or any surface that the radiation penetrates An area, accessible to individuals, in which the radiation levels could result in an individual receiving an absorbed B) dose in excess of 5,000 rads (50 grays) in 1 hour at 1 meter from the radiation source or any surface that the radiation penetrates An area, accessible to individuals, in which the radiation levels could result in an individual receiving an absorbed C) dose in excess of 5,000 rads (50 grays) in 1 hour at 30 centimeters from the radiation source or any surface that the radiation penetrates An area, accessible to individuals, in which the radiation levels could result in an individual receiving an absorbed D) dose in excess of 500 rads (5 grays) in 1 hour at 1 meter from the radiation source or any surface the radiation penetrates An area, accessible to individuals, in which the radiation levels could cause an individual to receive an absorbed E) dose in excess of 500 rads (5 grays) in 1 hour at 30 centimeters from the radiation source or any surface the radiation penetrates

The correct answer is: D VHRA is defined in 10 CFR Part 20.1003

Question Number: 958 Applied Radiation Protection Accelerators frequently use collimators as an important part of the beam delivery system. Since the primary beam strikes these collimators, one must consider all of the following EXCEPT: A) Heat generation and/or liquid cooling B) Induced radioactivity C) Energy dissipation D) Electromagnetic dielectric spatial TWT and RF interference from the ion source E) Using copper, brass or tungsten

The correct answer is: D When a particle beam strikes an object, we expect ionization of atoms, the generation of bremsstrahlung, activation of the materials (if the energy is sufficiently high), and the generation of heat. NCRP Report 144, pg. 24.

Question Number: 949 Applied Radiation Protection Accelerators frequently use collimators as an important part of the beam delivery system. Since the primary beam strikes these collimators, one must consider all of the following EXCEPT: A) Heat generation and/or liquid cooling B) Induced radioactivity C) Energy dissipation D) Electromagnetic dielectric spatial TWT and RF interference from the ion source E) Using copper, brass or tungsten

The correct answer is: D When a particle beam strikes an object, we expect ionization of atoms, the generation of bremsstrahlung, activation of the materials (if the energy is sufficiently high), and the generation of heat. NCRP Report No. 144.24.

Question Number: 888 Applied Radiation Protection A whole body counting report identifies a CDE to the lung of 45 Rem. If the deep dose exposure to the individual was 0.75 Rem the individual's Total Effective Dose Equivalent is: A) 5.25 rem B) 45.75 rem C) 11.26 rem D) 6.15 rem E) 2.1 rem

The correct answer is: D Wt for lung is 0.12 (10 CFR 20) CDE = 45 rem CEDE = CDE * Wt = 45 rem * 0.12 = 5.4 rem TEDE = DDE + CEDE = 0.75 rem + 5.4 rem = 6.15 rem

Question Number: 863 Applied Radiation Protection You have been assigned to cover a fuel re-rack job at a PWR. The types of radiation you should be concerned with during the job are: A) gamma and beta. B) gamma, beta and neutron. C) gamma, beta and alpha. D) gamma, beta, neutron, and alpha. E) beta and alpha.

The correct answer is: D You should be concerned with all four. Spent fuel pools can contain corrosion products (beta-gamma), fuel elements and pellets (beta-gamma-alpha), fail fuel (alpha-beat) and neutron sources (alpha-neutron). It is likely you will not be aware of everything in the pool so you should anticipate problems from any of the four.

Question Number: 991 Applied Radiation Protection One of the easiest methods to measure radon in a home is: A) HPGe detector with a flow through silver zeolite filter. B) take a direct reading with an ion chamber. C) take a direct reading with a GM detector. D) a charcoal filter. E) a silver zeolite filter.

The correct answer is: D Charcoal filters for radon sampling consist of charcoal, a diffusion barrier, desiccant and a container. Over the course of several days, radon gas diffuses into the charcoal and is adsorbed. The container is then sealed and counted later. See Gollnick "Measurement Of Radon Gas In Buildings," unit 10.

Question Number: 892 Applied Radiation Protection To remain in compliance with 10 CFR 61, you need to resample your waste streams in all of the situations below EXCEPT: A) Water chemistry parameters have changed B) After a fuel leak C) After a crud burst D) Semi-annually for confirmation E) When chemical decontamination may have removed some radionuclides selectively

The correct answer is: D Resample quarterly and yearly for confirmation. EPRI Radwaste Desk Reference: Question 1626.

Question Number: 879 Applied Radiation Protection The amount of tritium allowed by 10 CFR 20 that can be disposed of in sanitary sewage is: A) 74 GBq in a quarter. B) 37 GBq in a month. C) 1000 GBq in a year. D) 370 GBq in a quarter. E) 185 GBq in a year.

The correct answer is: E (5 Ci/yr)(3.7 x 10 10 Bq/Ci) = 1.85 x 1011 Bq or 185 GBq

Question Number: 962 Applied Radiation Protection Which of the following standards apply to laser safety? A) 49 CFR 173 B) ANSI C95 C) ICRP 66 D) NCRP 138 E) ANSI Z136

The correct answer is: E ANSI Z136 "Safe Use of Lasers" is the standard that applies to laser safety.

Question Number: 987 Applied Radiation Protection Agreement States may regulate the use of all the following EXCEPT: A) Naturally occurring radioactive materials B) Technologically enhanced radioactive materials C) Accelerator produced radioactive materials D) Reactor produced radioactive materials E) Reactors

The correct answer is: E Agreement States do not regulate reactors; this is reserved for the NRC.

Question Number: 900 Applied Radiation Protection The effectiveness of radiation therapy can be increased by: A) heat. B) chemicals. C) type of radiation. D) dose rate or dose fractionation. E) All of the above

The correct answer is: E All the listed factors affect the way target cells react to ionizing radiation.

Question Number: 862 Applied Radiation Protection The dominant external radiation hazard in fuel cycle facilities requiring work with unshielded forms of uranium is: A) alpha. B) photoelectric gammas. C) thermal neutrons. D) fast neutrons. E) beta.

The correct answer is: E Although uranium and its progeny are mostly an internal hazard, their beta decays produce a significant external hazard. Bevelacqua, Contemporary Health Physics: Problems and Solutions. 1995. See Table A.2

Question Number: 994 Applied Radiation Protection The majority of inhalation dose to underground uranium minors is from: A) Ar-41 B) Tritium C) Co-60 D) Uranium E) Radon

The correct answer is: E Although uranium is present, typically methods are utilized to control particulate generation, and uranium is a "heavy metal" toxin, more than a radiological hazard (see the Center For Disease Control's ATSDR on Uranium, executive summary). The other nuclides are associated with a reactor. The radon originates with the radon daughter of uranium.

Question Number: 867 Applied Radiation Protection In non-power reactors the radionuclide that is the principal environmental emission is: A) Fe-59 B) Mn-56 C) Co-60 D) Sb-124 E) Ar-41

The correct answer is: E Ar-41 generated from neutron interaction with Ar-40 in air is found predominantly in facilities specifically designed for neutron beam experiments. Maletskos, C.J.,Radiation Protection at Nuclear Power Plants.

Question Number: 980 Applied Radiation Protection When shielding a multi-Curie Sr-90 source, you must: A) ensure that the shield thickness will completely stop the Sr-90 alpha. B) use as much lead as possible to stop the high energy gamma ray emitted. C) consider the neutrons emitted if it comes in contact with beryllium. D) use only borated polyethylene to stop the albedo neutrons. E) consider bremsstrahlung production.

The correct answer is: E Bremsstrahlung can be produced in significant quantities from beta emitters. Also, do not forget that typically Sr-90 is in secular equilibrium with Y-90.

Question Number: 996 Applied Radiation Protection When transporting radioactive material, a placard: A) must list the radionuclide and quantity of radioactive materials in units of Bq. B) is required for all vehicles with White I, Yellow II and Yellow III labels. C) is only needed for the front and back of the vehicle. D) must be on all sides of a package. E) does not provide the transportation index.

The correct answer is: E Placards do not contain any information other than "Radioactive" and the hazard class (7). They are not on packages, only vehicles, and are only required for shipments containing Yellow III, LSA, SCO and exclusive use shipments.

Question Number: 927 Applied Radiation Protection The "planned special exposure" provision in 10 CFR 20 is to be used under what circumstances? A) For personnel overexposures after they occur B) Whenever the licensee wants to keep an individual's routine exposure low C) Whenever the licensee requires additional allowable exposure for a worker D) Only in emergency situations E) Only in exceptional situations where alternatives are unavailable or impractical

The correct answer is: E Planned special exposures (PSEs) are not to be used for routine dose extensions or on-the-spot dose extensions under emergency conditions. Specific requirements can be found in 10 CFR Part 20.1206. Regulatory Guide 8.35 further clarifies the use of PSEs.

Question Number: 876 Applied Radiation Protection The effective dose equivalent allowed by EPA Protective Action Guides for life saving or protection of large populations is: A) < 50 mSv B) < 750 mSv C) < 250 mSv D) 250 mSv E) > 250 mSv

The correct answer is: E Provided lower dose is not practical. Life saving or protection of large populations on a voluntary basis to persons fully aware of risks involved is > 250 mSv (> 25 rem) EPA-400-R-92-001

Question Number: 858 Applied Radiation Protection Most newer mammographic units contain a moving grid to reduce scattered radiation, which if not used would result in a reduction of in contrast of the image produced. A) 5 - 10% B) 60 - 75% C) 10 - 20% D) 70 - 80% E) 30 - 45%

The correct answer is: E Reduction in image contrast caused scattering radiation which is 40 - 80% of the radiation exiting the tissue. Hendee, Health Physics Journal, 1995, Vol 69, No5.

Question Number: 915 Applied Radiation Protection According to 10 CFR 20 the definition of special nuclear material includes: A) Plutonium. B) Uranium 233. C) Uranium enriched in U233. D) Uranium enriched in U235. E) All of the above

The correct answer is: E Special Nuclear Material (SNM) is fissile and requires special controls as specified in 10 CFR Part 70. See 10 CFR Part 20 and Part 70 ( Definitions section 20.1003)

Question Number: 899 Applied Radiation Protection What neutron quality factor did the BEIR V report use to calculate dose equivalent? A) 3 B) 5 C) 10 D) 17 E) 20

The correct answer is: E The BEIR V report assumed a relative biological effectiveness value of 20 for bomb neutrons to gamma rays in analyzing radiocarcinogenesis. (1990). BEIR V. Washington, DC .

Question Number: 974 Applied Radiation Protection After a release of I-131, milk may contain I-131. The best way to rapidly detect I-131 in milk in containers would be which of the following? A) BF3 detector B) Fixed (laboratory based shielded) GM Detector C) ZnS based detector D) Liquid Scintillation Detector (LSC) E) NaI detector

The correct answer is: E The NaI detector would be effective in detecting the 0.364 MeV photons from I-131.

Question Number: 967 Applied Radiation Protection Within a room where x-rays are used, the walls where an x-ray beam is NEVER directed are required to have: A) no shielding. B) shielding sufficient for the primary beam. C) shielding sufficient for the leakage radiation. D) shielding sufficient for the scattered radiation. E) shielding for both leakage and scattered radiation.

The correct answer is: E The leakage and scatter radiation are stopped by the secondary shielding. See NCRP 147.

Question Number: 997 Applied Radiation Protection If isokinetic sampling is not used, the resulting samples: A) should be immediately refrigerated. B) will not be representative of the Ar-41 concentration. C) will not be representative of the H-3 concentration. D) will normally be representative of the particulate present. E) may over or under sample for smaller particles.

The correct answer is: E The purpose of isokinetic sampling is to match the flow rate of the air in a stack or duct so that the particle sizes collected are representative of those in the air. When the air sample flow rate is too fast or slow, smaller particles may be over represented (faster flow, draw in nearby small particles that should have just passed by) or under represented (slower sample rate).

Question Number: 911 Applied Radiation Protection The tissue weighting factor for the bone surfaces according to 10 CFR 20 is: A) .25 B) .12 C) .10 D) .06 E) .03

The correct answer is: E The radiation weighting factor weighs the dose equivalent to the individual organ to the probability of stochastic effects (cancer and genetic effects) to the whole body. 10 CFR Part 20 definitions section 20.1003.

Question Number: 983 Applied Radiation Protection Background is counted for 1 minute and 25 counts are measured. The standard deviation is: A) 1 B) 1.732 C) 2.5 D) 5 E) Not measurable in this situation.

The correct answer is: E The square root of the number of counts is the standard deviation since the poisson distribution is assumed. You may also take the square root of the count rate divided by the count time to obtain the standard deviation.

Question Number: 1001 Applied Radiation Protection The Fukushima reactor accident: A) resulted in over 19,000 people dying due to acute radiation effects. B) caused an explosion that initiated an earthquake, followed by flooding. C) caused at least 10 workers to die from acute effects of radiation. D) killed more workers and members of the public from acute radiation sickness than all of the deaths at Chernobyl combined. E) released mostly volatile fission products and noble gasses.

The correct answer is: E There were no deaths due to acute radiation effects.

Question Number: 961 Applied Radiation Protection Which of the following is NOT a major concern for low and intermediate energy accelerators? A) Bremsstrahlung x-rays due to charged particles B) Characteristic x-ray radiation C) Prompt gamma radiation D) Neutron charged particles emitted E) Delta ray induction of radioactivity in klystrons and magnetrons

The correct answer is: E These only occur in higher energy accelerators. NCRP Report 144, pg. 34.

Question Number: 893 Applied Radiation Protection A Notice of Violation will not be issued when an individual receives a hot particle exposure that is equal to or less than the beta emission criteria of: A) 25 µCi -hours B) 50 rad at 7 mg/cm2 over 1 cm2 C) 10 rad at 1 mg/cm2 over 1 cm2 D) 100 µCi -hours E) 75 µCi -hours

The correct answer is: E This corresponds to 1.0 x 10 10 beta particles. NRC Information Notice IN90-48

Question Number: 901 Applied Radiation Protection According to 10 CFR 20 radiological surveys should be performed to evaluate the: A) extent of the radiation levels. B) concentrations of radioactive materials. C) quantities of radioactive materials. D) potential radiological hazards that could be present. E) All of the above

The correct answer is: E This is similar to any industrial hazard - it must be properly characterized in the workplace. 10 CFR Part 20.1501

Question Number: 894 Applied Radiation Protection A criticality accident has occurred at a facility. You have been assigned to determine which individuals have received a large dose. Using a GM probe you obtain 0.5 mr/hr above background on an individual. Thei estimated dose is: A) background. B) 0.5 mrad. C) 5 rad. D) 25 rad. E) 75 rad.

The correct answer is: E Thumbrule: 0.1 mr/hr using GM probe on individuals exposed during criticality accident is 15 Rad. (0.5 mr/hr) * (15 rad) / (0.1 mr/hr) = 75 rad Johnson and Birky, Health Physics and Radiological Health , Chapter 3.

Question Number: 976 Applied Radiation Protection When a radioactive package labeled Yellow II, according to DOT regulations, the external surfaces must be checked for contamination by: A) performing a direct "frisk" of all surfaces using a GM probe. B) wiping 100 cm2 and checking the wipe for contamination. C) using an ion chamber in "integrate" mode on contact with all surfaces. D) performing a direct "frisk using a GM probe and a ZnS probe over all surfaces of the package. E) wiping 300 cm2 of the external surfaces and checking the wipe for contamination.

The correct answer is: E Wiping an area of 300 square cm of the external surface concerned with an absorbent material, using moderate pressure, and measuring the activity on the wiping material is required for all radioactive labeled packages, excepted packages, empty containers, LSA and SCO packages. Sufficient measurements must be taken in the most appropriate locations to yield a representative assessment of the non-fixed contamination levels. See 49 CFR Part 173 for required package contamination controls.

Question Number: 923 Applied Radiation Protection Which of the following bioassay methods may be found in a uranium facility? A) In-vivo monitoring using sodium iodide detectors B) In-vivo monitoring using hyperpure germanium detectors C) In-vivo monitoring using phoswich detectors D) In-vitro monitoring using urinanalysis and fecal analysis E) All of the above

The correct answer is: E X-rays and gamma emissions from U-235 and U-238 daughters can be detected as low as 1 nCi with state of the art systems.

Question Number: 796 Applied Radiation Protection The specific activity which represents the DOT-regulated radioactive material lower limit is: A) 0.005 µCi . B) 0.005 µCi /gm. C) 0.002 µCi. D) 0.002 µCi /gm E) nuclide-specific.

The correct answer is: E DOT lists exempt radionuclide values in 49 CFR Part 173.436

Question Number: 709 Applied Radiation Protection In the shielding equation I = Ioe-µx, if µ is larger it means that the shielding material for the photon energy of interest is: A) a more effective shield. B) a less effective shield. C) a material with undetermined shielding properties. D) no more effective than if µ was smaller. E) None of the above

The correct answer is: A In the equation, µ represents the linear attenuation coefficient, which is the portion of the radiation interacting with the shielding material per unit thickness of the material. As this interacting portion grows larger, the shielding material is becoming more effective.

Question Number: 724 Applied Radiation Protection A "restricted area" is an area where an individual, if he were continuously present in the area, could receive a radiation dose: A) in excess of two mrems in any one hour or in excess of 100 mrems in one year. B) in excess of two mrems in any one hour or in excess of 100 mrems in five consecutive days. C) in excess of five mrems in any one hour or in excess of 100 mrems in one week. D) in excess of two mrems in any one hour or in excess of 100 mrems in any one week. E) in excess of five mrems in any one hour or in excess of 100 mrems in five consecutive days.

The correct answer is: A 10 CFR Part 20 (1991) defines a restricted area as any area controlled by the licensee for the purpose of protection of personnel against radiation or radioactive materials. The quantitative criteria stated in the question are the upper bounds of an "unrestricted area".

Question Number: 795 Applied Radiation Protection Personnel monitoring equipment is required if an individual working in the area is likely to receive: A) 10% of the annual dose limit in any one year. B) 25% of the annual dose limit in any one year. C) 500 mrem in one year. D) 5 mrem in any one hour. E) 100 mrem in any consecutive days.

The correct answer is: A 10 CFR Part 20 requires personnel monitoring devices when an individual is likely to exceed 10% of the annual total effective dose equivalent limit.

Question Number: 704 Applied Radiation Protection The exposure rate of the turbine floor of a boiling water reactor plant could be expected to be decreased to less than 1% at least after shutdown? A) five minutes B) one hour C) twenty-four hours D) thirty-six hours E) forty-eight hours

The correct answer is: A A good thumb rule for decay is that after seven half-lives, activity is less than 1% of original activity (it is actually 1/(2)7, or 1/128). Since the nuclide of concern on the turbine floor of a BWR is N-16 (T 1/2 = 7.1 sec; 6.1,7.1 MeV gamma's), it would take only 49.7 seconds to decay to less than 1%. N-16 is produced from the (n,p) reaction on O-16 in the reactor coolant.

Question Number: 710 Applied Radiation Protection The buildup factor for a gamma source and shield geometry at a point outside the shield is 20. The fraction of the dose contributed by unscattered photons is: A) 0.05 B) 0.1 C) 0.5 D) 0.8 E) 0.9

The correct answer is: A Buildup factor is defined as the ratio of all photon radiation at a point outside a shield to primary, unscattered photons at that point. It is a correction factor which is used with the linear attenuation coefficient when calculating for broad beam ,"poor" geometries. If the buildup factor is 20, the ratio is 20:1, and the fraction of unscattered photons is 1/20, or 0.05.

Question Number: 778 Applied Radiation Protection When leak testing an industrial radiography source, the contamination sample should be obtained: A) on the inside of the source tube. B) inside the source housing. C) on the surface of the sealed source. D) on the handle of the camera housing. E) on the source locking mechanism.

The correct answer is: A Choice A is the best answer, since if the source is leaking contamination, the contamination will be distributed on the inside of the source tube when the source is moved from the shielded to the unshielded position. It is not ALARA, and even dangerous, to directly swipe a sealed source of the activity required for industrial radiography sources.

Question Number: 713 Applied Radiation Protection How are tools or equipment transferred from a contaminated area? A) Sealed in clean plastic bags B) Decontaminated thoroughly before being transferred to another contaminated area C) Painted D) Sealed in aluminum boxes E) Immersed in heavy water

The correct answer is: A Contaminated equipment is usually bagged until it can be decontaminated or used again in a contaminated area. If the equipment will be contaminated again after cleaning, it may be ALARA to simply store the contaminated equipment for future use.

Question Number: 765 Applied Radiation Protection The four emergency classifications of an accident at a nuclear power plant, in ascending order of severity, are: A) Unusual Event, Alert, Site Area Emergency, General Emergency B) General Emergency, Site Area Emergency, Alert, Unusual Event C) General Emergency, Alert, Site Area Emergency, Unusual Event D) General Emergency, Unusual Event, Site Area Emergency, Alert E) Alert, Site Area Emergency, General Emergency, Unusual Event

The correct answer is: A Each level of emergency classification is declared based upon the fraction of the EPA Protective Action Guides (PAGs) reached at the site boundary, or whether the PAGs will be exceeded offsite.

Question Number: 725 Applied Radiation Protection Leak test of sealed radioactive sources should be sensitive enough to detect: A) 0.005 µCi. B) 0.1 µCi. C) 0.5 µCi. D) 100 dpm/100 cm2. E) 1000 dpm/100 cm2.

The correct answer is: A For sealed sources of licensable quantity, the NRC requires semiannual leak tests with a minimum detectable activity no greater than .005 µCi.

Question Number: 733 Applied Radiation Protection In planning shielding for walls of an x-ray room that are not subjected to the direct beam, consideration is given to provide shielding for: A) scattered radiation from all sources and leakage from the x-ray tube. B) scattered radiation from natural background. C) scattered radiation from the patient only. D) leakage radiation from the x-ray tube. E) secondary scattered radiation from the walls.

The correct answer is: A NCRP Report No. 147 addresses structural shielding for medical x-ray facilities. Primary protective barriers protect against the primary beam only, while secondary protective barriers protect against scatter and leakage. The most scatter occurs at the patient.

Question Number: 750 Applied Radiation Protection In what way can we establish whether or not an individual could exceed some percent of the DAC? A) Obtain an air sample B) Carry out a general area survey C) Carry out a loose surface contamination survey D) Carry out a bioassay procedure E) Check area radiation monitors

The correct answer is: A Since the DAC is the Derived Air Concentration, comparison of exposures to any limits with DAC as the unit requires air sampling.

Question Number: 748 Applied Radiation Protection For removing radioactive contamination from the skin, your best choice would be: A) a mild soap. B) a dilute KMnO4 solution. C) a dilute H2SO4 solution. D) an acetone-alcohol solution. E) a strong caustic solution.

The correct answer is: A Soap and lukewarm water is always the first choice for removal of radioactive contamination from the skin.

Question Number: 761 Applied Radiation Protection According to the BEIR V Report, the number of additional cancer mortalities in a population of 100,000 people exposed to 10 rad of low-LET radiation would be: A) 800. B) 100. C) 50. D) 30. E) 10.

The correct answer is: A The 1990 BEIR V Report increased the estimates of cancer mortalities for low-LET radiation by a factor of about 8:3 over its 1980 BEIR III estimates. The increase was largely due to more complete data regarding neutron and gamma dose contribution to the atomic bomb blast survivors.

Question Number: 777 Applied Radiation Protection Radioactive material may be transported through the U.S. Postal Service provided that: A) the surface radiation level on the package does not exceed 0.5 mrem/hr. B) the surface radiation level on the package does not exceed 50 mrem/hr. C) the surface radiation level on the package does not exceed 200 mrem/hr. D) the transport index on the package does not exceed 1.0. E) the transport index on the package does not exceed 10.

The correct answer is: A The USPS limits packages to "Limited Quantities" of radioactive material. The 0.5 mrem/hr surface limit is one of the criteria for a Limited Quantity.

Question Number: 716 Applied Radiation Protection A "working level" is that amount of Rn-222 daughter products which would result in: A) 1.3 E+05 MeV per liter of air. B) 1 ALI in six months. C) 1 ALI in twelve months. D) one third of the DAC. E) one third of the MPC.

The correct answer is: A The definition of working level includes the daughter products only, and not the radon itself. One working level is also approximately equal to 100 pCi/L or three times the occupational DAC for Rn-222. The occupational limit for uranium miners is 4 working level-months per year, which is equal to 170 working level-hours * four months.

Question Number: 762 Applied Radiation Protection The NRC's annual limit for the sum of the deep dose equivalent and the committed dose equivalent is: A) 50 rem. B) 15 rem. C) 10 rem. D) 5 rem. E) 2 rem.

The correct answer is: A The limit described is referred to as the Total Organ Dose Equivalent (TODE). Based upon 1977 ICRP recommendations, the annual TODE limit for all organs and tissues except the lens of the eye is 50 rem. The annual limit for the lens under NRC regulations is 15 rem.

Question Number: 702 Applied Radiation Protection An adequate Radiation Safety Program is the ultimate responsibility of: A) the owner of the licensed facility. B) the operator of the source of radiation. C) the Radiation Safety Officer. D) the line supervisor. E) the radiation worker.

The correct answer is: A The radioactive materials license is issued to the owner of the facility. It is the licensee who is responsible for all aspects of compliance with the license, including the implementation of a radiation safety program. It is the duty of the RSO to administer the program.

Question Number: 731 Applied Radiation Protection Which of the following are distinguishing colors and symbol for radiation warning signs? A) Yellow and magenta with a trifoil B) A yellow and magenta atom C) A black and yellow atom D) A solid yellow trifoil on black background E) A red and white molecule

The correct answer is: A Under 10 CFR Part 20 , yellow and black may also be used.

Question Number: 744 Applied Radiation Protection A photon beam is reduced to 0.1 of its initial intensity by lead with a linear attenuation coefficient of 0.567/cm. What is the shielding thickness? A) 4.06 cm B) 2.30 cm C) 1.0 cm D) 0.567 cm E) 0.05 cm

The correct answer is: A Use the shielding equation: I = Io e-(µx) and let Io = 1 Therefore: 0.1 = 1 e- (0.567cm)(x) 0.1 = e- (0.567cm)(x) ln(0.1) = - (0.567cm)(x) 4.06 cm = x

Question Number: 742 Applied Radiation Protection If the TVL of concrete for Co-60 photons is 20 cm, and the total photon yield is 2.5 MeV/d, the thickness of concrete required to reduce the exposure rate from a 1000 Ci point source to 250 mR/hr at 6 meters is which of the following? A) 45 cm B) 75 cm C) 100 cm D) 137 cm E) 250 cm

The correct answer is: A Use the shielding formula, D = 6CEN, and the inverse square law. Since D = 6CEN is used, meters will need to be converted to feet: 6 meters * 3.28 meters/ft = 19.685 ft Then: I = Io e - (ln10/TVL) (x) And: Io = 6 CEN/(19.685) 2 = (6 * 1000 * 2.5)/387.5 = 38.71 R/hr Therefore: .250 R/hr = 38.71 R/hr [e - (ln10/20cm) (x)] .250/38.71 = e- (ln10/20cm)(x) ln(.250/38.71) = - (ln10/20cm)(x) 43.8 cm = x

Question Number: 798 Applied Radiation Protection You enter a room and are directing cleanup of a liquid spill. What precautions do you prescribe to prevent the spread of contamination? A) Clean the edges of the spill first. B) Install shielding around the spill. C) Work rapidly to minimize the dose. D) Install ventilation to assist in the cleanup of the spill. E) Dilute with large volumes of water.

The correct answer is: A When cleaning up a radioactive spill, the spill should be cleaned from the outside in, from low contamination to high.

Question Number: 758 Applied Radiation Protection When transporting a Highway Route Controlled Quantity of radioactive material outside of the licensee's state, notification must be made to: A) affected state governors and EPA. B) affected state governors or their designated deputies and the regional DOT offices. C) regional NRC and DOT offices. D) regional NRC offices, DOT offices, and the EPA. E) affected state governors and the NRC.

The correct answer is: B A Highway Route Controlled Quantity is a Type B quantity of radioactive material which is 3000 times the applicable "A" value or 27,000 curies, whichever is less. The advance notification requirements are specified in 10 CFR Part 71 and 49 CFR Part 173 .

Question Number: 783 Applied Radiation Protection A toluene and P-32 spill occurs in a lab. The BEST selection for protective clothing and cleanup is: A) acid suit, rubber gloves, and absorbent. B) plastic boots, gloves, and apron with faceshield and absorbent material. C) lab coat, rubber gloves, and room ventilation. D) airline suit, rubber boats, and room ventilation. E) lab coat, rubber gloves, and dilution with demineralizer water.

The correct answer is: B Answer B appears to be the best choice since it provides face, trunk, hand, and foot protection and specifies a cleanup medium. Answer A provides no face protection (and toluene is a solvent, not an acid), and Answer D is respiratory protection overkill, with no cleanup method specified.

Question Number: 740 Applied Radiation Protection Four shields are available for shielding a point source of gamma radiation. There is a 0.5 inch thick sheet of aluminum, a 1 inch thick sheet of aluminum, a 0.5 inch thick sheet of lead, and a one inch thick sheet of lead. Which of these shields will result in the highest build-up factor at a point outside the shielded source? A) The 0.5 inch thick sheet of lead B) The 1 inch thick sheet of lead C) The 0.5 inch thick sheet of aluminum D) The 1 inch thick sheet of aluminum E) The buildup will be greatest when the source is unshielded.

The correct answer is: B Buildup factor typically increases with both the atomic number of the shielding material and the thickness of the shield. Without any other specific data, such as the energy of the photon(s) and the linear attenuation coefficients of the shielding materials, B is the best answer.

Question Number: 715 Applied Radiation Protection Which of the following surveys should be performed on a daily routine basis? A) Occupied/unoccupied work areas B) Occupied work areas C) Fixed contamination in unrestricted areas D) Hot spots E) Neutron radiation in unoccupied work areas

The correct answer is: B From a general standpoint in radiation protection, only areas which are occupied need to be surveyed daily to update radiological status. Routine surveys are performed in unoccupied areas in some instances, when it is difficult to determine in advance if the area may need to be occupied.

Question Number: 705 Applied Radiation Protection The goal and future requirement regarding high level liquid waste is: A) transformation by irradiation to shorter lived, less toxic materials. B) vitrification and deep ground burial. C) use as a heat source. D) disposal into geological formations. E) disposal into salt formations.

The correct answer is: B High level waste, which includes spent reactor fuel and liquid wastes from the solvent extraction process, requires stabilization and disposal in deep ground geologic repositories. Although vitrification technology and deep ground burial are practiced in other industrialized nations, the U.S. lags behind in implementing these methods.

Question Number: 784 Applied Radiation Protection In the formula I = BIo e-(µx), the attenuation coefficient for the shielding material is represented by: A) x B) µ C) e D) I E) B

The correct answer is: B In this classical shielding equation: I = shielded radiation intensity Io = unshielded radiation intensity B = buildup factor µ = attenuation coefficient of the shield x = shield thickness

Question Number: 781 Applied Radiation Protection The MAIN purpose of isokinetic sampling in a stack is to: A) increase turbulent flow from insertion of the sampling head into the gas stream. B) obtain the same representative fraction of small and large particles as in the stack gas. C) prevent deposition of the particles in bends of the sample tubing. D) collect a relatively large proportion of the smaller particles from the gas stream so as to approximate the ideal aerosol median aerodynamic diameter (AMAD) of 1 µm. E) maintain a constant gas temperature during sampling.

The correct answer is: B Isokinetic sampling is established when the mass flow rate (linear flow rate) is equal in the process line and the sample line. This is established by regulating volumetric sample flow in the sample line based upon the ratio of process and sample line diameters.

Question Number: 707 Applied Radiation Protection A Pu-Be source should be stored: A) in a secured area and surrounded with sufficient lead shielding to reduce the exposure rate to permissible levels. B) in a properly posted and secured area and surrounded with sufficient hydrogenous shielding to reduce the dose equivalent rate to permissible levels. C) in a safe. D) in a locked room posted with "Caution: High Radiation Area" signs. E) in a locked room posted with "Caution: Neutron Radiation Hazard".

The correct answer is: B Pu-Be is a neutron producing source, so it must be shielded with hydrogenous material. Since Pu is special nuclear material as defined by the NRC, it must also be secured under 10 CFR Part 70.

Question Number: 708 Applied Radiation Protection How many centimeters of lead were required for a shield if seven half-value layers were used to shield a beam of gamma photons? (attenuation coefficient for lead = 0.4559 per centimeter) A) 1.52 cm B) 10.6 cm C) 13.2 cm D) 15.2 cm E) 30.4 cm

The correct answer is: B Since the attenuation coefficient (µ) would be equal to .693/HVL Then: 1 HVL = .693/µ = .693/(.4559/cm) = 1.52 cm And: 7 HVL = 7 * 1.52 cm = 10.64 cm

Question Number: 786 Applied Radiation Protection Who is ultimately responsible for NRC license compliance at a university? A) RSO B) Administration C) State D) County E) NRC

The correct answer is: B Since the license is issued to the owner of the licensed facility, the administration of the university would probably be the entity responsible for compliance. The next closest answer is the state, but only if it were a state university. The RSO is only responsible for implementing the radiation safety aspects of the license.

Question Number: 719 Applied Radiation Protection When using a charcoal cartridge with a full-face air-purifying respirator, the protection factor afforded for I-125 is: A) 0 B) 1 C) 50 D) 2,000 E) 10,000

The correct answer is: B Under NRC licenses, unless special studies and documentation are performed to demonstrate an actual protection factor greater than 1 for charcoal cartridges against radioiodine, 1 must be used.

Question Number: 793 Applied Radiation Protection In a linear accelerator radiation survey, the radiation protection technologist should be aware of interference which may give erroneous readings from: A) skyshine. B) magnetic fields. C) neutrons. D) x-rays. E) microwaves.

The correct answer is: B Strong magnetic pulsed fields are present around an operating accelerator. These fields can affect electron flow in instrument circuitry, causing erroneous response. Skyshine, neutrons, and x-rays could all be real concerns in an accelerator, as could microwaves. Microwaves, however, would not produce a response in an ionizing radiation detector.

Question Number: 764 Applied Radiation Protection An accidental criticality incident subjects a number of people to suspected high neutron exposures. If none of the people were wearing personnel dosimetry, how would you rapidly screen them to determine which individuals received high exposures? A) Send them to the medical department for a blood count. B) Place a GM detector on the abdomen and look for meter deflection. C) Send each person for a complete physical examination. D) Send the people to the hospital for bedrest and observe them for radiation sickness. E) Collect samples for urinalysis.

The correct answer is: B The abdomen or armpit represent large blood pools that can be effective indicators of accident-scale neutron exposures. The Na-23(n,gamma)Na-24 reaction produces a response in a G-M detector, with a reading of 1 mrad/hr on the instrument representing an acute neutron dose equivalent of 500 rem.

Question Number: 712 Applied Radiation Protection What immediate action should be taken if skin is accidentally broken while working with radioactive substances? A) Immerse the wound in tepid water. B) Wash the wound under running water. C) Apply a liberal portion of titanium dioxide paste. D) Scrub with a brush using heavy lather and tepid water. E) Wash the wound vigorously with a damp cloth.

The correct answer is: B The danger in this scenario is absorption of radioactive materials into the bloodstream. When deconning an open wound, a flushing action is required.

Question Number: 772 Applied Radiation Protection The basic physical controls applied to protection against internal radiation hazards are: A) film badges, dosimeters, ion chambers, survey meters. B) ventilation, air cleaning equipment, respirators. C) time, distance, shielding. D) standards, regulations, procedures. E) bioassay, whole body counting, nose wipes.

The correct answer is: B The engineering controls (ventilation, filtration) should always be considered prior to the use of respiratory protection equipment.

Question Number: 768 Applied Radiation Protection The major off-site dose during the Three Mile Island accident was due to which of the following? A) Cobalt-60 B) Xenon-133 C) Iodine-131 D) Iodine-125 E) Cesium-137

The correct answer is: B The highest dose equivalent to a member of the public as an immediate result of the accident was about 2 mrem. The radioiodines, which were originally projected to create significant dose off-site, reacted with NaOH in the containment spray and were essentially "rinsed" from containment. Krypton-85 was another significant contributor to the dose off-site.

Question Number: 782 Applied Radiation Protection Workers will cut into a pipe where fission and activation products are present six months after facility shutdown. Assuming respiratory protection is required, the proper device to select is: A) air-purifying half-mask with charcoal cartridge. B) air-purifying full-face respirator. C) air-purifying full-face respirator with charcoal cartridge. D) self-contained breathing apparatus. E) atmosphere-supplied full-face respirator.

The correct answer is: B The intent of this question centers on the recognition that the short-lived fission gases will not be present after a period of six months.

Question Number: 739 Applied Radiation Protection The linear attenuation coefficient of a shielding material for gamma photons varies depending on the density of the shielding material and the: A) mass of the shielding material. B) energy of the photon. C) photon yield. D) half-life of the isotope. E) half-life of the isotope.

The correct answer is: B The linear attenuation coefficient varies inversely with the incident photon energy over the typical range of photon energies found in applied radiation protection.

Question Number: 760 Applied Radiation Protection NCRP recommendations relative to radiation exposure of pregnant women include which of the following? A) Dose to the fetus during the first trimester should be less than 0.5 rem. B) Dose to the fetus during the entire term of gestation should be less than 0.5 rem. C) Pregnant women should be granted a three month leave of absence during the first trimester. D) Quarterly doses for pregnant women should not exceed 25% of the federal quarterly dose limit. E) All women of childbearing age should be considered pregnant and have their dose limits appropriately lowered.

The correct answer is: B These recommendations appear in NCRP Report No. 116 (1993). The fetus is most susceptible to radiation during the first trimester of gestation. Current regulations leave the decision of exposure limitation to the pregnant radiation worker.

Question Number: 732 Applied Radiation Protection A preoperational environmental monitoring program would gather data for all of the following purposes EXCEPT: A) determining the significant pathways of exposure to the critical population. B) measuring the radioactivity accidentally released. C) locating areas of high background radioactivity. D) determining the crops which form critical exposure pathways. E) establishing mean meteorological condition.

The correct answer is: B This is not such a tricky question. Since the facility is in a preoperational state, no radioactivity has been released.

Question Number: 751 Applied Radiation Protection A fixed air filter at a nuclear power reactor monitored by a GM detector shows a SUDDEN increase in activity, then levels off at the higher activity. This is probably due to: A) an increase in radon/thoron concentrations. B) the release of a short half-life beta emitter at a constant rate. C) the release of Kr-88 or Xe-138 from the reactor for a short period. D) a puff release of a short-lived beta-gamma emitter. E) None of the above

The correct answer is: B This question describes a continuous air monitor. Radon/thoron increases would not be sudden. Brief releases of short-lived beta emitters, as described in C and D would rise for a period and then recede. A constant release of a short-lived nuclide would reach equilibrium on the filter, causing the reading to level off at the equilibrium value.

Question Number: 779 Applied Radiation Protection What is the attenuation coefficient for a material if it takes 10.6 centimeters of the material to reduce a 128 R/hr gamma source to 1 R/hr? (Assume no buildup) A) 12.07/cm B) 0.4577/cm C) 0.083/cm D) 0.1356/cm E) 1.356/cm

The correct answer is: B Use I = Io e-(µx) Therefore: 1 = 128 e -(µ)(10.6 cm) ln(1/128) = -(µ)(10.6 cm) 0.4577/cm = µ

Question Number: 734 Applied Radiation Protection The major engineering problem associated with the storage of high level wastes is: A) accidental criticality. B) heat production. C) theft of 239-Pu contained in the waste. D) the high content of transuranic elements. E) chemical corrosiveness.

The correct answer is: B High level waste, which includes spent reactor fuel, liquid waste from the solvent extraction process, and solids into which such liquids have been converted, emits significant decay heat. This heat can have an adverse effect on engineered and geologic materials.

Question Number: 767 Applied Radiation Protection A technician responds with emergency medical personnel to a contaminated injured man. What is his first priority? A) Assisting with the decontamination of the wound B) Informing medical personnel of radiological conditions C) Medical treatment of the patient D) Evacuation of the patient E) Movement of the patient to a low background area

The correct answer is: B Since medical personnel are already present, the duty of the technician is to provide radiological coverage for the response operation. If medical personnel were not present, the condition of the patient would be the technician's first priority.

Question Number: 745 Applied Radiation Protection Air sample results from an unoccupied area show a constant concentration of radioactive material of 0.8 DAC. To comply with the requirements of 10 CFR 20, the radiation protection technologist must: A) post the area "Caution: Airborne Radioactivity Area". B) require any individual who may enter the area to wear a respiratory protection device. C) take no action since the area is unoccupied. D) post the area "Caution: Airborne Radioactivity Area" and "Respiratory Protection Required". E) post the area "Caution: Airborne Radioactivity Area" and require any individual who may enter the area to wear a respiratory protection device.

The correct answer is: C 10 CFR Part 20 requires posting of an airborne radioactivity area at 1 DAC or when an individual could receive 12 DAC-hours during the hours present in one week (this would be 0.3 DAC for a forty hour week in the area). Since the area is unoccupied and 1 DAC is not exceeded, no posting is required under Part 20.

Question Number: 721 Applied Radiation Protection The use of a Radioactive Yellow III label on a package containing radioactive material, shipped non-exclusive use, implies: A) that the radiation exposure rate from any point on the surface of the package does not exceed 0.5 mR/hr. B) that the package contains Fissile Class II radioactive material and the transport index does not exceed 0.5. C) that the radiation exposure rate from any point on the surface of the package does not exceed 200 mR/hr and the transport index does not exceed 10. D) that the radiation exposure rate from any point on the surface of the package does not exceed 10 mR/hr and that the transport index does not exceed 0.5. E) that the package contains Fissile Class II radioactive material for which the transport index exceeds 10.

The correct answer is: C A Yellow III label is required under 49 CFR Part 173 if the surface radiation level exceeds 50 mR/hr or the level at one meter (the transport index) exceeds 1.0.

Question Number: 780 Applied Radiation Protection To use elevated release dispersion modeling during a design-basis accident, the release stack must be: A) at least five times its height from the reactor building. B) at least two times its height from the nearest adjacent building. C) at least two and one-half times the height of the nearest adjacent building. D) at least two times the height of the reactor building. E) at least two and one-half times its height from the nearest adjacent building.

The correct answer is: C According to NRC guidelines, the stack must also be at least one times its height away from the nearest adjacent building. If these criteria are not met, mixed-mode or ground release modeling must be used.

Question Number: 718 Applied Radiation Protection The basic physical methods applied to protection against external radiation hazards are: A) film badges and dosimeters. B) protective clothing. C) time, distance, and shielding. D) whole body counting and bioassay. E) G-M survey meters.

The correct answer is: C Decreasing time and increasing distance and shielding are fundamental principles of applied radiation protection.

Question Number: 720 Applied Radiation Protection The maximum allowable radiation level at contact of a package shipped in other than an exclusive use vehicle is: A) 1 mR/hr B) 2.5 mR/hr C) 200 mR/hr D) 500 mR/hr E) 1000 mR/hr

The correct answer is: C For a package shipped non-exclusive use, the maximum allowable surface radiation level under DOT's 49 CFR Part 173 is 200 mR/hr. A package with a surface reading between 50 and 200 mR/hr requires a Radioactive Yellow III label.

Question Number: 730 Applied Radiation Protection Secondary protective barriers in medical x-ray facilities are designed to protect persons from: A) the primary beam only. B) leakage radiation only. C) leakage and scattered radiation only. D) primary beam, leakage radiation and scatter. E) scattered radiation only.

The correct answer is: C In shielding design for medical x-ray suites, primary protective barriers are implemented for protection against the primary beam, while secondary protective barriers protect against the secondary sources, tube leakage and scatter. The most scattering occurs at the patient. Shielding design for medical x-ray facilities is discussed in NCRP Report No. 147 (2004).

Question Number: 797 Applied Radiation Protection A nurse drops a 30 millicurie liquid I-131 solution at the only entrance to a patient's room, causing a spill. His immediate action should be to: A) acquire absorbent material at the nurses station. B) evacuate the patient. C) notify the RSO. D) check the hall for contamination. E) ventilate the room.

The correct answer is: C Prior to potentially becoming part of the problem, it is always a good practice to notify someone of the situation, your actions, and whether assistance is needed. Then, stop the spread of contamination and restrict access to the area. Since the spill is at the only entrance, evacuation of the patient is impractical.

Question Number: 735 Applied Radiation Protection Most operating light water nuclear power reactors limit the release of radioactive noble gases through the use of: A) absolute filters. B) a series of activated charcoal beds. C) delay lines or tanks. D) freeze-out traps. E) dilution fans.

The correct answer is: C Since radioactive noble (inert) gases are not filtrable, adsorbable, or absorbable, the control of these fission products is decay, with the subsequent filtration of particulate daughter products.

Question Number: 699 Applied Radiation Protection For calculating dose to an organ from internal sources, the "specific effective energy" of a radionuclide is BEST described as: A) the energy given off by the radionuclide per unit of radionuclide activity. B) the energy absorbed per unit mass of the organ per unit of radionuclide activity. C) the energy absorbed per unit mass of the organ per disintegration of the radionuclide. D) the energy given off by the radionuclide per disintegration of the radionuclide. E) the energy transferred to the organ per unit of radionuclide activity.

The correct answer is: C The "SEE" is used in the Medical Internal Radiation Dosimetry (MIRD) dose modeling technique.

Question Number: 728 Applied Radiation Protection EPA Protective Action Guidance for members of the general public during the early phase of a nuclear accident includes: A) a whole body dose exceeding 25 rem and a thyroid dose exceeding 125 rem. B) a whole body dose exceeding 75 rem and no limit to the thyroid. C) a total effective dose equivalent exceeding 1 rem and a committed dose equivalent to the thyroid exceeding 5 rem. D) a whole body dose exceeding 25 rem and no limit to the thyroid. E) a whole body dose exceeding 1 rem and a thyroid dose exceeding 25 rem.

The correct answer is: C The EPA PAGs were revised in 1991 under EPA 400, which supersedes EPA 520. PAGs are anticipated dose levels where protective action, such as sheltering or evacuation, should be considered.

Question Number: 723 Applied Radiation Protection Remediation of areas contaminated with uranium mill tailings, under UMTRA, includes unrestricted release criteria of: A) less than 200 µR/hr inside habitable structures and radon levels less than 0.1 working level. B) less than 20 µR/hr inside habitable structures and radon levels less than 1 working level. C) less than 20 µR/hr inside habitable structures and radon levels less than 0.02 working level, not to exceed 0.03 working level. less than 200 µR/hr inside habitable structures and radon levels less than 0.02 working level, alpha contamination less than 220 dpm/cm2 . E) less than 2 µR/hr inside habitable structures and radon levels which result in less than 4 working-level months per year.

The correct answer is: C The EPA sets forth these requirements in 40 CFR Part 190 for remediation of properties contaminated with uranium mill tailings.

Question Number: 726 Applied Radiation Protection In the siting of nuclear reactors, the exclusion radius refers to: A) the distance downwind from a reactor that a person may receive a dose of 25 rem to the whole body from the entire passage of the radioactive cloud. B) the distance specifying the area which must be secured by a barbed wire fence. C) the distance downwind from the reactor that a person may receive either a dose of 25 rem to the whole body or 300 rem to the thyroid if he stands there for two hours after the onset of the postulated accident. D) the distance specifying the area that people must be excluded from. E) None of the above

The correct answer is: C The NRC defines exclusion radius and low population zone in 10 CFR Part 100 , "Reactor Site Criteria". The low population zone differs from the exclusion radius only in the exposure time, which for the low population zone is the entire duration of the passage of the radioactive cloud.

Question Number: 753 Applied Radiation Protection The agency which approves the design of respiratory protection devices is: A) EPA B) NRC C) NIOSH D) OSHA E) FEMA

The correct answer is: C The National Institute of Occupational Safety and Health approves all respiratory protection devices used under NRC and OSHA regulations.

Question Number: 754 Applied Radiation Protection The airborne concentration for a particulate radionuclide with a DAC of 2 x 10 -7µCi/ml is measured as 1 x 10 -3 µCi/ml. If a worker's stay time is four hours and he cannot exceed 8 DAC-hours, what respiratory protection device should be assigned? A) Full-face air-purifying B) SCBA in demand mode C) SCBA in pressure-demand mode D) Positive-pressure air-purifying E) Atmosphere-supplied hood

The correct answer is: C The PF (Protection Factor) must be calculated, then the device selected. Use the DAC-hour calculation to arrive at the PF: [(Concentration/DAC)/PF] * (hrs) = DAC-hours [(1 x 10 -3/2 x 10 -7)/PF] * 4 hrs = 8 DAC-hours (1 x 10 -3/2 x 10-7)/PF = 2(1 x 10-3/2 x 10-7)/2 = PF PF = 2500 The only device with a PF of 2500 or greater is the SCBA in pressure-demand mode, with a PF of 10,000. PF's appear in 10 CFR Part 20, Appendix A.

Question Number: 792 Applied Radiation Protection Regarding respiratory protection, which of the following statements is MOST true? A) Respirators are an effective method of reducing exposure to hazardous materials and should be utilized whenever possible. B) Respirators should never be considered if they may increase physical stress to the worker. C) Removal of hazardous materials should be attempted prior to considering the use of respiratory protection. D) Respiratory protection should only be used in environments which are Immediately Dangerous to Life and/or Health. E) Respirators are always more practical in hazardous environments than implementing engineering controls.

The correct answer is: C The use of respiratory protection equipment adds risk to the worker's job. To minimize risk, which is the goal of the safety and health specialist, use of engineering controls and source removal/reduction should be considered prior to the assignment of respiratory protection.

Question Number: 759 Applied Radiation Protection At what level does loose alpha contamination become unacceptable on a radioactive materials package to be shipped in a non-exclusive use conveyance? A) 10 x 10-5 µCi /cm2 B) 10 x 10-5 µCi /100 cm2 C) 10 x 10-6 µCi /cm2 D) 22 dpm/cm2 E) 220 dpm/cm2

The correct answer is: C These limits appear in 49 CFR Part 173. The limit for beta-gamma contamination is ten times the limit for alpha contamination. For a non-exclusive use shipment, that limit would be 10 x 10 -5 µCi /cm2. These limits are also frequently expressed in units of dpm/cm 2.

Question Number: 775 Applied Radiation Protection As a result of Three Mile Island accident, the USNRC requires nuclear power plants to install noble gas and containment radiation monitors in which of the following detection ranges? A) 1 x 102 µCi /cc to 1 x 10 8 µCi /cc for noble gas and 1 to 8 R/hr for radiation B) Up to 1 x 10 5 µCi /cc for noble gas and 1 to 8 R/hr for radiation C) Up to 1 x 10 5 µCi /cc for noble gas and 1 to 1 x 10 8 R/hr for radiation D) Up to 1 x 10 2 µCi /cc for noble gas and 1 to 1 x 10 8R/hr for radiation E) Up to 1 x 10 2 µCi /cc for noble gas and 1 to 1 x 10 8 R/hr for radiation

The correct answer is: C These requirements were implemented following the accident, because operators interpreted offscale readings to be instrumentation malfunction.

Question Number: 788 Applied Radiation Protection The apparent half-life of an air sample run for one-half which contains Rn-222 and its daughters is which of the following? A) 10 minutes B) 20 minutes C) 35 minutes D) 50 minutes E) 90 minutes

The correct answer is: C This fact is useful in applied health physics to distinguish between long-lived alpha-emitters and radon progeny on an air sample. If half the activity is removed in 35 minutes, radon progeny is indicated.

Question Number: 789 Applied Radiation Protection Immediate telephone notification to the USNRC operations center is required when an individual receives an acute total effective dose equivalent of at least: A) 1 rem. B) 5 rem. C) 25 rem. D) 150 rem. E) 375 rem.

The correct answer is: C Under 10 CFR Part 20, immediate notification for acute radiation exposures is required at doses equal to five times the annual limits. 24-hour notification is required if acute doses are one time the annual limits.

Question Number: 749 Applied Radiation Protection An air sampler is run for 45 minutes at a rate of 60 liters per minute. Net activity of the sample is 15,000 counts per minute using an instrument with a 10% counting efficiency. The approximate airborne concentration is: A) 2.5 x 10-5 µCi/ml B) 2.5 x 10-7 µCi/ml C) 2.5 x 10-8 µCi/ml D) 2.5 x 10-9 µCi/ml E) 2.5 x 10-10 µCi/ml

The correct answer is: C Use the air activity calculation: C = net cpm/(vol)(efficiency)(dpm/µCi) = 15000/(45m * 60 L/m * 1 x 10 3ml/L)(.1)(2.22 x 106dpm/µCi) = 2.5 x 10-8 µCi/ml

Question Number: 741 Applied Radiation Protection If a shielding material has a half-value layer of 0.5 inches and a buildup factor of 2, how much shielding will be required to reduce the exposure rate from 200 milliroentgen per hour to 50 milliroentgen per hour? A) 0.5 inches B) 1.0 inches C) 1.5 inches D) 2.0 inches E) 3.0 inches

The correct answer is: C Use the shielding equation: I = BIo e-(ux) 50 = (2) (200) e - [(.693/0.5) (x)] 50/400 = e- [(.693/0.5) (x)] ln (50/400) = - (.693/0.5) (x) 1.5 inches = x

Question Number: 776 Applied Radiation Protection Suggested sizes of the plume exposure and ingestion pathway emergency planning zones, respectively, are: A) 1 mile and 3 miles. B) 5 miles and 15 mile. C) 10 miles and 50 miles. D) 15 miles and 60 miles. E) 20 miles and 100 miles.

The correct answer is: C NRC's NUREG 0654 on emergency planning guidance for nuclear power plants sets forth these recommendations. They are based on an external critical exposure inside a ten mile radius and an internal critical exposure pathway outside of a ten mile radius.

Question Number: 722 Applied Radiation Protection An agreement state is: A) a state which agrees to disposing its own radioactive waste. B) a state which agrees to abide by federal regulations within its borders. C) a state which agrees to maintain occupational exposures ALARA. D) a state which asserts its willingness to regulate the use of radiation and radioactive materials within its borders. E) a state which allows radioactive shipments to transverse its boundaries.

The correct answer is: D A radioactive materials licensee in an agreement state is licensed by the state, in a non-agreement state is licensed by the NRC. A power reactor licensee is always licensed by the NRC under 10 CFR Part 50, regardless of agreement state status.

Question Number: 794 Applied Radiation Protection Decontamination of a hot cell is most easily accomplished if the hot cell is: A) constructed of styrofoam. B) coated with water-based paint. C) constructed of concrete. D) constructed of stainless steel. E) supplied with negative pressure ventilation.

The correct answer is: D Hot cells are generally closed containments used to work on high-contamination or high-radiation components, sometimes with remote handling devices. Smooth, non-porous materials are best for ease of decontamination.

Question Number: 774 Applied Radiation Protection Federal regulations governing licensing and radiation safety for industrial radiographic operations can be found in: A) 10 CFR 20. B) 10 CFR 25. C) 10 CFR 30. D) 10 CFR 34. E) 10 CFR 35.

The correct answer is: D Industrial radiographic operations also are subject to the requirements of 10 CFR Part 20, "Standards for Protection Against Radiation".

Question Number: 700 Applied Radiation Protection What is the BEST method of disposal of dog carcasses which have been treated with a radionuclide with a 78-hour half life? A) Wait 3.25 days and prepare for shipment to a disposal facility or incinerate. B) Wait 1.625 days and bury. C) Wait 3.25 days and bury. D) Wait 32.5 days and prepare for shipment to a disposal facility or incinerate. E) Wait 32.5 days and bury.

The correct answer is: D It is common for radioactive materials licenses to allow the disposal of radioactive materials after ten half-lives as "clean" materials. In this case, the waste is still biohazardous, so proper burial or incineration is indicated.

Question Number: 746 Applied Radiation Protection A compound which is effective to remove radioactive contamination from the skin, after soap and lukewarm water have been ineffective is which of the following? A) Acetone B) Diethylene-triamine-pentaacetate (DTPA) C) Trinitro toluene (TNT) D) Potassium permanganate (KMnO4) E) Nitrile triacetic acid

The correct answer is: D KMnO4 will remove the first few layers of skin, and should only be used under medical supervision. Titanium dioxide paste has the same application. DTPA is an internal chelating agent for plutonium and americium. A risk analysis should be performed relative to the radioactivity to be removed whenever using these types of materials.

Question Number: 727 Applied Radiation Protection The two organizations which review and approve emergency response plans for commercial nuclear power plants are: A) EPA and NRC. B) FEMA and EPA. C) NCRP and EPA. D) NRC and FEMA. E) NRC and NCRP.

The correct answer is: D NRC reviews the licensee's emergency preparedness plan, while FEMA reviews that of the state and local organizations.

Question Number: 738 Applied Radiation Protection Which of the following thicknesses of materials would be the best choice for shielding a 5 Ci preparation of P-32? A) 1/8 inch of lead B) 1/4 inch of aluminum C) One foot of air D) One inch of lucite plastic E) Any of the above

The correct answer is: D P-32 is a "pure beta emitter" with a 14.82 day half-life and a 1.7 MeV Emax. It is typically used in therapeutic medical procedures. When shielding beta particles, low atomic number materials are used to reduce the probability of bremsstrahlung photons.

Question Number: 773 Applied Radiation Protection The BEST shielding for a Phosphorus-32 source would be which of the following? A) Lead B) Copper C) Tin D) Polyethylene E) Iron

The correct answer is: D Since P-32 is a 1.7 Emax "pure beta-emitter", a low-Z material should be used as shielding so that bremsstrahlung is prevented. P-32 is typically used in therapeutic nuclear medicine, and has a half-life of 14.28 days.

Question Number: 752 Applied Radiation Protection Which of the following respiratory protection devices would provide the greatest protection factor in an Iodine-131 atmosphere? A) Full-face negative pressure with combination cartridge B) SCBA in demand mode C) Powered air-purifying respirator D) Full-face airline respirator E) Supplied-air half-mask

The correct answer is: D The atmosphere supplied device of those given with the greatest protection factor is the full-face airline, with a PF of 2000. SCBA in the demand mode only has a PF of 100. In the pressure-demand mode it is 10,000.

Question Number: 766 Applied Radiation Protection At one time, a one year old child's thyroid was used as the critical organ for off-site doses of I-131, primarily because: A) of differences in effective energy term. B) of differences in retention. C) of differences in uptake. D) of its smaller mass (by a factor of 10) compared to that of an adult. E) of the greater milk consumption of a child as compared to the consumption of an adult.

The correct answer is: D The child thyroid is no longer used as part of the Protective Action Guides from EPA 400. Under EPA 520, it had been used because, for a unit intake of radioiodine, the dose would be greater for an organ of less mass. That is, since dose is measured in ergs/gm, decreasing the number of grams for the same number of ergs means a higher dose.

Question Number: 769 Applied Radiation Protection The amount of shielding required to reduce a 2.5 roentgen per hour gamma source to 2.5 milliroentgen per hour is: A) six half-value layers. B) seven half-value layers. C) two tenth-value layers. D) three tenth-value layers. E) four tenth-value layers.

The correct answer is: D The transmission factor for the shielding in this problem is 2.5mr/2.5R, which is equal to 1/1000. It becomes clear that, since 1000 is an exponential of 10, TVLs will appear in the answer. So use: I = Io (1/10)n Then: 2.5 = 2500 (1/10)n n 2.5/2500 = (1/10) log(2.5/2500) = log(1/10)n -3 = -1n 3 = n

Question Number: 737 Applied Radiation Protection Which of the following is in the order of MOST effective to LEAST effective shielding materials for gamma radiation sources? A) Water, lead, concrete, iron B) Water, lead, iron, concrete C) Lead, water, iron, concrete D) Lead, iron, concrete, water E) Lead, iron, water, concrete

The correct answer is: D These materials are listed in decreasing order of density. The probability of gamma interaction increases with the number of electron shells, which increases with atomic number.

Question Number: 756 Applied Radiation Protection Leak testing of sealed radioactive sources used for radiography should be performed: A) prior to use of the device. B) prior to and following transportation of the device. C) prior to and following transportation of the device and prior to the use of the device. D) every six months. E) annually and prior to use of the device.

The correct answer is: D These requirements appear with other industrial radiography regulations in 10 CFR Part 34. The contamination survey required prior to and following transportation of the device is required as part of the transportation regulations, and is not a leak test of the integrity of the sealed source itself.

Question Number: 763 Applied Radiation Protection Allowable radiation and contamination levels on protective clothing are established primarily by the: A) NRC. B) NCRP. C) state licensing body. D) licensee. E) ICRP.

The correct answer is: D This is a good example of administrative levels imposed by a facility to ensure that regulatory limits are not exceeded.

Question Number: 747 Applied Radiation Protection The minimum recommended face velocity for a fume hood is: A) 75 cubic feet per minute. B) 75 linear feet per minute. C) 125 cubic feet per minute. D) 125 linear feet per minute. E) 250 cubic feet per minute.

The correct answer is: D This is a typical face velocity for a radiochemical fume hood, in accordance with industrial hygiene good practices. Face velocity is expressed as a mass, rather than volumetric, flow rate.

Question Number: 790 Applied Radiation Protection The most effective ALARA program will be based on: A) a good radiological control supervisor. B) worker awareness of hazards in the work place. C) a large radiological control staff. D) a strong management commitment to radiation protection. E) the size of the work force.

The correct answer is: D Without a management commitment to ALARA, the other elements of an effective program cannot exist. The NRC addresses the importance of this commitment in Regulatory Guide 8.10, "Operating Philosophy for Maintaining Occupational Radiation Exposures As Low As Reasonably Achievable".

Question Number: 714 Applied Radiation Protection General area dose rates should be recorded: A) as the dose rate at the chest. B) as the dose rate at the waist. C) as the dose rate at the knees. D) as the highest dose rate between the head and knees. E) as the highest dose rate between the chest and knees.

The correct answer is: D "General area dose rates" are usually taken to determine deep dose equivalent rates in a work area, and don't include shallow dose equivalent rates to extremities (arms below the elbow, legs below the knee).