Energy Exam 2 Nuclear Power

According to Einstein, if somehow we could transform mass into energy...

it would be possible to "liberate" huge amounts of energy

August 6 1945

oBomb drop of Hiroshima (little boy bomb) followed by the bomb drop of nagasaki (fat man bomb)

Bill Chadwick

oDetermined that the weight of an electron or a proton is 1/1300 of the proton's mass oThere must be something else that carries all the weight oHe found the existence of the neutron

Leo Sziland

oHungarian oJewish oHe ran away from hungary, tented up in London, and ended up in US oHe was worried about development in Germany that they might be using the radioactive fission reaction to generate an atomic bomb. He contacted Einstein about it. He said he got a letter from lise mitner saying she knows that otto and fritz know about the development of the bomb. FDR was president and he responded by giving them money and telling them to figure it out HIS OPINIION DIFFERS FROM ENRICO'S ABOUT THIS*

Sequence of Events Leading to the Accident

-25 April 1986: Test was to check whether, in the event of a shutdown enough electrical power to operate the emergency equipment and core cooling pumps until the diesel power supply came online. -As the reactor shutdown proceeded, the reactor operated at approximately half power when the electric load dispatcher refused to allow further shutdown. As part of the test the emergency core cooling system was switched off and the reactor carried on at half power. At about 23:00hrs on 25th April the grid controller agreed to a further reduction in power. -For the test the reactor was to be stabilized at 1,000MW prior to shutdown, however, due to operational error the power fell to about 30MW where the positive void coefficient became a problem. The operators tried to raise the power by freeing all the control rods manually and at 01:00hr on 26 April the reactor stabilized at 200MW. -Shortly afterwards an increase in coolant flow and a drop in steam pressure occurred requiring the operators to withdraw nearly all the rods. The reactor then became very unstable and the operators had to make adjustments every few seconds to maintain a constant power.

Fission Products

-Adding a neutron to 235U makes in unstable. -It breaks apart giving 2-3 neutrons, lots of energy and gama rays. -Gamma-rays have the smallest wavelengths and the most energy of any other waves in the electromagnetic spectrum.

Fusion Reactions

-bringing things together instead of breaking things apart -creates a lot of heat -how do we fuse them together? that's the problem

Common Exposures

-one coast to coast flight: 3 mrem -chest radiograph, anterior/posterior view: 15-25 mrem/view -chest radiograph, lateral view: 50-65 mrem/view -screening mammography (film/screen combination): 60-135 mrem/view -computerized tomography of body (20 slices): 3000-6000 mrem

Total number of nuclear reactors in the world

430 out of which US has almost 1/4

1905

Einstein--> e=mc^2

Problems and Issues with Nuclear Technology

Nuclear Proliferation, Waste Disposal, Spent Nuclear Fuel

Nuclear Batteries

Nuclear batteries based on thermoelectric conversion and containing radioactive isotopes are used as micro-watt power sources for pacemakers. A larger version has been proposed for use in an artificial heart.

Direct internal and external radiation

Radiotherapy has the advantage over chemotherapy of being specific to the cancer or tumor involved. It is applied directly to the site of the cancer and, therefore, does less damage to healthy tissue.

World War 2

blamed everything on germany 1930s-->nazi

Half lives of some radioactive isotopes

uranium-238: 4.47 billion years thorium-234: 24.1 days protactinium-234m: 1.17 minutes uranium-234: 245000 years thorium-230: 8000 years radium-226: 1600 years radon-222: 3823 days polonium-218: 3.05 minutes lead-214: 26.8 minutes bismuth-214: 19.7 minutes polonium-214: 0.000164 seconds -lead 210: 22.3 years -bismuth 210: 5.01 days -polonium 210: 138.4 days -lead 206: stable

Typical pellet of uranium

weighs about 7 grams (0.24 ounces). It can generate as much energy as 3.5 barrels of oil, 17,000 cubic feet of natural gas, or 1,780 pounds of coal.

The way its arranged on the abbreviation of the element

•Bottom left: Number of electrons or protoms, top left: number or neutrons or protons, bottom right: numbers of atoms in the molecule, top right: number of charge

Ivadium

•Pierre Curie and Madam Curie and Henri Becquerel went to Sweden to get the nobel award •They only allowed the boys to go on stage •Madam Curie and her niece then discovered Polonium, they both got the award and it was the first time a woman ever spoke at a nobel prize award

Protons, neutrons, electrons

•Protons and neutrons are in the nucleus, electrons rotate around the nucleus •Electrons were found first because people were using high voltage •Electrons have a charge and therefore can be attracted to or repelled

Einstein's Letter to Roosevelt

**look on powerpoint -August 2, 1939, albert einstein wrote a letter to the american president, franklin d. roosevelt "In the course of the last four months it has been made probable--through the work of Joliot in France as well as Fermi and Szilard in America--that it may become possible to set up nuclear chain reactions in a large mass of uranium... This new phenomenon would also lead to the construction of bombs... A single bomb of this type, carried by boat or exploded in a port, might very well destroy the whole port together with some of the surrounding territory." -he urged roosevelt to begin a nuclear program without delay -In later years Einstein deplored the role he had played in the development of such a destructive weapon: "I made one great mistake in my life," he told Linus Pauling, another prominent scientist, "when I signed the letter to President Roosevelt recommending that atom bombs be made."

Fission and Chain Reaction

**picture in powerpoint, can't draw it here it's pretty impossible -neutron-->lighter element (energy)-->235U -each 235U emits two neutrons, two lighter elements, and energy

Atomic Number (Z)

-# of protons or # of electrons (assuming they're the same number because we're assuming a neutral). Written as Z. -e.g. Hydrogen has 1 proton and 1 electron, therefore atomic number is 1. -Equal number of electrons and protons guarantee charge neutrality. -If the electron leaves the hydrogen atom, the atom will become positively charged. H+. This is called an "ion". -Other examples: Atomic number 8 means 8 electrons and 8 protons. This is Oxygen. -Atomic number is written as subscript: 8O, 1H, 6C....

Enrico Fermi

-1934, the italian physicist enrico fermi disintegrated heavy atoms by spraying them with neutrons -unfortunately, he didn't realize that he had achieved nuclear fission -december 1938, however, otto hahn and fritz strassman in berlin did a similar experiment with uranium and were able to verify a world-shaking achievement -nuclear fission!!!! oWorked with uranium 235 (U235), means that it has 235 neutrons o*Interest was energy production, he wanted to see how to utilize energy. He wants to make a nuclear reactor oU235 broke up o100 total mass of uranium: you get 80 of something and 10 of something else, there is still 10 missing. What happened to it? No one could figure it out

Exposure at Chernobyl

-Approximately 134 plant workers and firefighters battling the fire at the Chernobyl power plant received high radiation doses--80,000 to 1,600,000 mrem-- and suffered from acute radiation sickness. Of these, 28 died within the first three months from their radiation injuries. Two more patients died during the first days as a result of combined injuries from the fire and radiation.

events continued...positive void coefficient

-At this time the operators reduced the flow of feedwater to maintain the steam pressure. Also pumps that were powered by the slowing turbine provided less and less cooling to the reactor. This created additional steam in the cooling channels (positive void coefficient) and the operators could not control a power surge estimated to 100 time the nominal power. -The sudden increase in temperature caused part of the fuel to rupture, fuel particles then reacted with the water creating a steam explosion which destroyed the reactor core. A second explosion added to the destruction two minutes later. (Cause unknown) -Air rushed into the core and ignited the graphite moderator blocks which burned for several days spewing radioactive dust in the atmosphere.

Nuclear Proliferation

-Civilian nuclear technology could be used to create fissile materials for use in nuclear weapons. -This concern is known as nuclear proliferation, and is a major reactor design criterion. -While the enriched uranium used in most nuclear reactors is not concentrated enough to build a bomb, the technology used to enrich uranium could be used to make the highly enriched uranium needed to build a bomb. -In addition, breeder reactor designs such as CANDU can be used to generate plutonium for bomb making materials. -It is believed that the nuclear programs of India and Pakistan used CANDU-like reactors to produce the fissionables for their weapons.

Details on three ile island

-Cost: 1.5 Billion Dollars -Controversial reports on increased lung cancer. -TMI II is permanently closed.

Technology become suspicious

-Currently, there are 109 nuclear power plants in operation. -No new plant had been ordered since 1978. -Nuclear Power contributes 22% to total USA need. -France generates 79% of its power from Nuclear technology. (Highest in the world)

Nuclear Energy: the first test of the world's first man-made nuclear reactor

-Enrico Fermi's famous "pile," CP-1, took place on December 2, 1942, in a squash court under the stands of the University of Chicago's Stagg Field. -The pile was a black, greasy, flattened mass. It was odd looking, combining the size of an average garage with the shape of a doorknob. Inside, it was stacked with 771,000 pounds of 16-inch graphite bricks, 80,590 pounds of uranium oxide pucks, and 12,400 pounds of uranium-metal slugs. -The uranium pucks fitted into holes bored into the graphite bricks in a roughly spherical pattern. CP-1 cost about $1 million to build. It had no shielding or emergency cooling devices.

Diagnostic Uses

-Examples of radioactive tracer medical procedures. -Myocardial perfusion imaging maps the blood flow to the heart. -Bone scans can detect the spread of cancer six to 18 months sooner than X-rays. -Kidney scans are much more sensitive than X-rays or ultrasound in fully evaluating kidney function. -Imaging with radioactive technetium-99m can help diagnose bone infections in young children at the earliest possible stage. -Laboratory techniques using radioactivity can detect underactive thyroids in newborn babies, making prompt treatment possible and saving many children from mental retardation.

Fermi's Pile

-Fermi intended to keep the reactor at less than half a watt of power, but no one doubted that its mechanism, if it worked, could someday be applied to the production of power. -Fermi's young physicist colleague Walter Zinn, were already thinking about power for civilian electricity. -When enough initial fissions in the U-235 nuclei took place, Fermi reasoned, a chain reaction would occur, each fission causing two more fissions, two causing four, four causing eight, eight causing sixteen. The geometric progression could ultimately have generated enough heat and radiation to cause an uncontrolled runaway chain reaction in the pile, if Fermi didn't limit the reactions with control rods.

Health and Economic Effects

-Figures from the Ukraine Radiological Institute suggest that over 2,500 deaths were caused by the Chernobyl accident. 116,000 people evacuated and another 200,000 people resettled. -$12.8 Billon of disruption occurred to the Soviet Economy. -immeasurable psychological problems

Types of bombs

-Fission bombs (in general) -Gun-triggered fission bomb (Little Boy), which was detonated over Hiroshima, Japan, in 1945 -Implosion-triggered fission bomb (Fat Man), which was detonated over Nagasaki, Japan, in 1945

Detonation

-Free neutrons must be introduced into the supercritical mass to start the fission. -To bring the subcritical masses together into a supercritical mass, two techniques are used: -Gun-triggered -Neutrons are introduced by making a neutron generator which is activated when the two subcritical masses come together.

A sense of scale for the Nuclear World

-If we set the height of an average adult human being at about 170cm (5'7") then: -a human red blood cell would be about 70,000 times smaller than we are -an atom would be about 10,000,000,000 times smaller than we are -an atom's nucleus would be about 100,000,000,000,000 times smaller than we are -a proton (positively charged unit inside an atom's nucleus) would be about 1,000,000,000,000,000 times smaller than we are

Chain Reaction and Moderator

-If you get those two neutrons to enter other uranium nuclei, you can start a chain reaction and release an enormous amount of energy. -The neutrons released by the fission of uranium move very fast. To get the released neutrons into other uranium nuclei, they have to be slowed down. The substance that slows the neutrons is called a moderator. Enrico Fermi, was the first to make this adjustment. He used graphite, a form of carbon, as the neutron-slowing moderator.

Supercritical Mass

-In a fission bomb, the fuel must be kept in separate subcritical masses, which will not support fission, to prevent premature detonation. -Critical mass is the minimum mass of fissionable material required to sustain a nuclear fission reaction. -The two or more subcritical masses must be brought together to form a supercritical mass, which will provide more than enough neutrons to sustain a fission reaction, at the time of detonation

Pressurized water reactors (PWRs)

-In a typical commercial pressurized light-water reactor, the reactor core creates heat -Pressurized-water in the primary coolant loop carries the heat to the steam generator -The steam generator vaporizes the water in a secondary loop to drive the turbine, which produces electricity. -PWRs keep water under pressure so that it heats, but does not boil. Water from the reactor and the water in the steam generator that is turned into steam never mix. In this way, most of the radioactivity stays in the reactor area. •When the pressure is increased the boiling point •If the pressure becomes too high the pressure comes down, the pressurizer never closed at first and when the water came in again all the water was gone *picture slide 48

Plutonium 239

-In examining the results of his experiment Fermi also found an important serendipitous side effect. Some of the neutrons freed by the fission of Uranium 235 entered the nuclei of the plentiful Uranium 238 atoms and transformed them into Plutonium 239. -The significance of this side effect being that Plutonium 239, it just so happens, is also an easy atom to fission. -Ironically, the immediate application of Fermi's work became the creation of breeder reactors to make the Plutonium 239 necessary for future nuclear bombs. -Plutonium 239 was used in the bomb dropped over Nagasaki, while Uranium 235 was used on Hiroshima. -Later on, however, Fermi's reactor became the model upon which the nuclear power industry was created.

Breeder Reactors: extending the availability

-It is possible to extend the availability of nuclear fuel by 10,000 years by using Breeder reactors -Most French reactors are breeder reactors. -No US reactor is a breeder reactor although we invented the technology. -In 1977 Jimmy Carter, due to the fear that the Plutonium might be stolen from the reactors, banned the Breeder Reactor technology in USA. -All weapons now are made from Pu-239.

Waste Disposal

-Low level radiation garbage: Gloves, tailings, equipment, etc. -Spent nuclear fuel: The safe storage and disposal of nuclear waste is a difficult problem. Because of potential harm from radiation, the spent nuclear fuel must be stored in shielded basins of water, or in dry storage vaults or containers until its radioactivity decreases naturally ("decays") to safe levels. -This can take days or thousands of years, depending on the type of fuel. Most waste is currently stored in temporary storage sites, requiring constant maintenance, while suitable permanent disposal methods are discussed.

Natural Reactor

-More than 1.5 billion years ago, a nuclear fission reaction took place in an underground uranium deposit in Oklo, Gabon, Africa. -The fission reaction continued - off and on - for hundreds of thousands of years. -Eventually, the reactor shut down. -While it was active, the natural reactor generated fission products (wastes) very similar to those produced when fission occurs in modern nuclear reactors at power plants. Oklo Mine Site in Oklo, Gabon

Nuclear Technology: other uses

-Nuclear Weapons -Materials Research -Medicine -Agriculture: Sterilization

Yucca Mountain Project

-On July 23, 2002, President Bush signed House Joint Resolution 87, allowing the DOE to take the next step in establishing a safe repository in which to store our nation's nuclear waste. -The Department of Energy is currently in the process of preparing an application to obtain the Nuclear Regulatory Commission license to proceed with construction of the repository. 77,000-ton capacity

Violation of Procedures

-Only 6 - 8 control rods were used during the test despite there being a standard operating order stating that a minimum of 30 rods were required to retain control. -The reactor's emergency cooling system was disabled.

Breeder Reactors

-Plutonium-239 produces significantly more energy than Uranium-235 -Plutonium-239 can be produced in reactors in which Uranium-238 covers the main fission material Uranium- 235. -These are called breeder reactors. -These are the most protected reactors. •They are the most dangerous in that they reproduce their fuel •Uranium 235 is the radioactive material •Coat the whole core with uranium 238, goes through a radioactive decay process, and you end up with plutonium

Design Fault in the RBMK reactor

-Reactor is unstable at low power -Steam pockets form that cause power surges (positive void coefficients)

When a bomb explodes, 3 things happen:

-Supercritcality: Each ejected neutron collides with a U-235. -The split happen very fast (in 10-12 seconds) -Tremendous amount of energy is liberated in the form of heat and gamma rays.

Nuclear Accidents (three mile island)

-The accident at the Three Mile Island Unit 2 (TMI-2) nuclear power plant near Middletown, Pennsylvania, on March 28, 1979, was the most serious in U.S. commercial nuclear power plant operating history. -No deaths or injuries to plant workers or members of the nearby community. -But it brought about sweeping changes involving emergency response planning, reactor operator training, etc. -It also caused the U.S. Nuclear Regulatory Commission to tighten and heighten its regulatory oversight.

Three mile island accident ********see slide 73

-The accident began about 4:00 a.m. on March 28, 1979, when the plant experienced a failure in the secondary, non-nuclear section of the plant. -The main feedwater pumps stopped running, caused by either a mechanical or electrical failure, which prevented the steam generators from removing heat. -First the turbine, then the reactor automatically shut down. -Immediately, the pressure in the primary system (the nuclear portion of the plant) began to increase. -In order to prevent that pressure from becoming excessive, the pilot-operated relief valve (a valve located at the top of the pressurizer) opened. -The valve should have closed when the pressure decreased by a certain amount, but it did not. -Signals available to the operator failed to show that the valve was still open.

The Second World War

-The development of the bomb continued. And on August 6, 1945, the Enola Gay, an American airplane, dropped the first atomic bomb ever used in warfare on Hiroshima, Japan, eventually killing over 140,000 people. -On August 9, 1945, the United States dropped a second atomic bomb, this time on the Japanese city of Nagasaki. The drop was one mile off-target, but it killed 75,000 people. -little boy and the fat man -enola gay and little boy -bockscar and fatman -right after the end of WW2 in the western sector we were fighting with the soviets and war started

Detonation: implosion-triggered

-The implosion device consisted of a sphere of uranium-235 (tamper) and a plutonium-239 core surrounded by high explosives. -When the bomb was detonated, this is what happened: -The explosives fired, creating a shock wave. -The shock wave compressed the core. -The fission reaction began. -The bomb exploded.

Chernobyl Accident

-The only known Nuclear Power Plant accident where there was a loss of life.* (Japanese Takaimura accident) -On April 25th -26th, 1986 the World's worst nuclear power accident occurred at Chernobyl in the former USSR (now Ukraine). -The Chernobyl nuclear power plant located 80 miles north of Kiev had 4 reactors and whilst testing reactor number 4 numerous safety procedures were disregarded. -At 1:23 am the chain reaction in the reactor became out of control creating explosions and a fireball which blew off the reactor's heavy steel and concrete lid. -The Chernobyl accident killed more than 30 people immediately, and as a result of the high radiation levels in the surrounding 20-mile radius, 135,000 people had to be evacuated. Where is chernobyl? Upper Ukraine

The pile

-The pile contained 771,000 pounds of graphite, 80,590 pounds of uranium oxide and -12,400 pounds of uranium metal when it went "critical". It cost about $1 million to produce and build

Boiling Water Reactor (BWR)

-The reactor core creates heat and a single loop both delivers steam to the turbine and returns water to the reactor core to cool it. -The cooling water is force-circulated by electrically powered pumps. -Emergency cooling water is supplied by other pumps, which can be powered by onsite diesel generators. -Other safety systems, such as the containment building air coolers, also need electric power janoval power plant **picture slide 50

Units of Exposure to Radiation

-The unit of radiation dose is called a rad (the SI term is gray or Gy). A rad is equal to 0.01 Joules of energy absorbed per kilogram of tissue. -In order to convert this unit into a unit of biological dose (rem), we have to understand the characteristics of the ionizing radiation. Different types of radiation can produce more or less biological damage, per unit of absorbed dose, depending upon the characteristics of the ionizing radiation. -The unit of rem (the SI term is Sievert or Sv) is determined by multiplying the dose in rads to a quality factor (QF) assigned that particular radiation. The QF for most gammas, betas and x-rays is 1. For neutrons, the QF is 2 - 11 (depending on neutron energy) and 20 for alpha particles.

The Government Steps In

-Through many acts and organizations including the Atomic Energy Act of 1946 and the Congressional Joint Committee on Atomic Energy, the government made atomic energy in all its manifestations an absolute government controlled monopoly and sought to monitor and control nuclear development, building test reactors and even test weapons. -Between 1964 and 1970, U.S. utility companies placed orders for some 100 reactors. Most of those reactors are still in operation today.

Mass Number (A)

-Total number of protons and neutrons is Mass number A, e.g., Hydrogen has one proton. Therefore, Mass number of hydrogen is 1. It is written as 11H. (AZX) -Another example: Helium has a mass number 2. Two proton, two neutron, two electron. 24He -This is all about nucleus. (Nucleons) -This does not explicitly tell you how many neutrons are there in the nucleus. -Since there is no charge consideration, there could be more neutrons than protons. -For example, Carbon can have 12, 13 or 14 neutrons. These are called isotopes.126C, 136C, 146C -Notice, you can not change number of proton. (Why?) If we add a proton, it becomes Nitrogen.

Fission bomb

-U-235 is one of the few materials that can undergo induced fission. -If a free neutron runs into a U-235 nucleus, the nucleus will absorb the neutron, become unstable and split immediately.

235Uranium

-Uranium 235 (Mass Number 235, the sum the protons and neutrons in its nucleus) is a very rare element. In nature, uranium is usually found as uranium 238. -Uranium 235 is special because within its nucleus, the repelling electromagnetic forces of the protons and neutrons are very close to overcoming the nuclear force binding them together. In fact, it only takes adding one more neutron to make it break open and split. -This splitting was called fission, after a similar process that happens during cell division (Mitosis).

Decommissioning of Nuclear Power Plant

-What happens after the plant exceeds its projected life? -To date, 100 mines, 90 commercial power reactors, over 250 research reactors and a number of fuel cycle facilities, have been retired from operation. Some of these have been fully dismantled. -All construction materials, pipes, pumps, etc. have to be removed and recycled or stored. -We pay for the decommissioning.

Fission

-When the uranium atom splits the combined mass of the two fission fragments is less than the mass of the uranium nucleus. Some matter is converted into energy and on average 2 or 3 neutrons are released.

WHAT RESULTED FROM THIS?

-cooling water poured out of the stuck-open valve and caused the core of the reactor to overheat. -Because adequate cooling was not available, the nuclear fuel overheated to the point at which the zirconium cladding (the long metal tubes which hold the nuclear fuel pellets) ruptured and the fuel pellets began to melt. -It was later found that about one-half of the core melted during the early stages of the accident. -Although the TMI-2 plant suffered a severe core meltdown, the most dangerous kind of nuclear power accident, it did not produce the worst-case consequences that reactor experts had long feared. In a worst-case accident, the melting of nuclear fuel would lead to a breach of the walls of the containment building and release massive quantities of radiation to the environment. But this did not occur as a result of the Three Mile Island accident.

Thallium-208

-decays into lead-208 with a half-life of 3.05 minutes -20 atoms of thallium-208, 0 atoms of lead-208-->3.05 minutes elapse, 10 atoms of thallium-208, 10 atoms of lead-208-->3.05 minutes elapse, 5 atoms of thallium-208, 15 atoms of lead-208

Aftermath of Chernobyl

-deserted city of pripyat, chernobyl nuclear power plant in the background. ukraine -the dead plant -the ghost town -deserted secondary school -abandoned school inside exclusion zone -ghost cafe -fukushima power plant

Therapeutic Uses of Radioactive Materials in Medicine

-direct internal and external radiation -the example of thyroid disease and cancer -nuclear batteries

Example of one of the many reactions in the U-235 fission process

-enrico fermi's model did not calculate the energy expended in the process

July 17 1945

-first test of a nuclear bomb -alma gurda

WHAT DO YOU NEED FOR A NUCLEAR REACTOR?

-fuel, moderator, and control rods

Commercial Reactors in the US

-have been operating somewhat long in california and arizona, not many though with a high average capacity -no commercial reactors in alaska or hawaii -none in the midwest -moving towards the east, have been operating a lot longer and a lot more, lower average capacity

Leo Szilard

-hungarian jew, educated in berlin, escaped in 1933 to london and came to USA in 1936 (columbia university) -has patent on fission process (in UK) and on nuclear reactors (with Fermi) -he convinced einstein that the germans are developing the atomic bomb and therefore USA should start a program -wrote the einstein-szilard letter to franklin D roosevelt

An example of one of the many reactions in the U-235 fission process (look in powerpoint slide 33)

-impact by slow neutron with energy on order of an eV -U236 compound nucleus is unstable, oscillates -neutrons can initiate a chain reaction -fission yields fragments of intermediate mass, an average of 2.4 neutrons, and average energy about 214 MeV

Ernest Rutherford and Niels Bohr

-in the second decade of the century, a major step was taken in that direction when they described the structure of an atom more precisely -it was made up, they said, of a positively charged core, the nucleus, and of negatively charged electrons that revolved around the nucleus -it was the nucleus, scientists concluded, that had to be broken, disingtegrated, "split," if atomic energy was to be liberated

The simplest way to bring the subcritical masses together is to...

-make a gun that fires one mass into the other -A sphere of U-235 is made around the neutron generator and a small bullet of U-235 is removed. The bullet is placed at the one end of a long tube with explosives behind it, while the sphere is placed at the other end. A barometric-pressure sensor determines the appropriate altitude for detonation and triggers the following sequence of events: -The explosives fire and propel the bullet down the barrel. -The bullet strikes the sphere and generator, initiating the fission reaction. -The fission reaction begins. -The bomb explodes.

Secret KGB memo about Chernobyl Nuclear Power Plant

-not for publication -USSR COMMITTEE OF STATE SECURITY [KGB] February 21, 1979 No. 346-A -Moscow -Construction Flaws at the Chernobyl Nuclear Power Plant [AES] -According to data in the possession of the KGB of the USSR, design deviations and violations of construction and assembly technology are occurring at various places in the construction of the second generating unit of the Chernobyl AES, and these could lead to mishaps and accidents. -The structural pillars of the generator room were erected with a deviation of up to 100 mm from the reference axes, and horizontal connections between the pillars are absent in places. Wall panels have been installed with a deviation of up to 150 mm from the axes. The placement of roof plates does not conform to the designer's specifications. Crane tracks and stopways have vertical drops of up to 100 mm and in places .........

Enrico Fermi: radio dating

-you can tell how old something is -half life: within what time will its concentration go to half of its original value

isotope

12C, 13C, 14C

Hiroshima

140,000 people died in this, almost 70,000 instantly

Antoine Becquerel

1852-1908 -1/2 noble prize 1903

Piere Curie

1859-1906 -1/4 nobel prize 1903

Marie Curie

1867-1922 -1/4 nobel prize 1903 obsessive genius

Rutherford

1871-1937

Bohr

1885-1962

Ernest Rutherford

1900 -english guy -in the western sense of things most of the art was centered in france and paris -said the elements are like swiss cheese: the holes are like the nucleus and the stuff around it is the electrons

Avagadro's number

6.02 x 10^23

Nagasaki

75,000 people died in this, almost 30,000 instantly

The Manhattan Project

A MASSIVE ENTERPRISE TO PRODUCE AN ATOMIC BOMB -At the time Roosevelt received the letter, U.S. scientists believed that Nazi Germany was ahead of them in building this type of bomb. Roosevelt gave the note to an aide saying: "This requires action." -For the next six years scientists, engineers, generals and government officials joined hands in the Manhattan Project--a massive enterprise to produce an atomic bomb. -The government spent more than $2 billion (130,000 people) constructing a number of special research laboratories, hiring scientists and engineers, and building thirty-seven installations in nineteen states and Canada. -Oddly enough, despite the scope of the effort, the secret was so well kept that practically no one outside a small select circle knew what was going on. oOppenheimer→he was a womanizer and he couldn't do it on his own so he did it with the help of... oLeslie Groves, they created the Los Alamos Lab

History of Nuclear Technology: 1896

Antoine Henri Becquerel discovered radioactivity in uranium. Becquerel did not envision the atom bomb when he made his discovery

Rebirth of Nuclear Technology: 2006

As of 2006, Watts Bar 1 (Spring City Tennessee), which came on-line in 1997, was the last U.S. commercial nuclear reactor to go on-line.

How do we go from here and make something useful?

Chain Reaction •The neutrons that are coming out are too fast, if they are too fast they just leave without causing further fission •If not they cause further fission, so they must be slowed down •They need a moderator! •Ugh f this class idk •Moderator slows down the neutrons→ graphite

General Omar N. Bradley

Chief of Staff, United States Army, who said in 1948, "We have too many men of science, too few men of God. We have grasped the mystery of the atom and rejected the Sermon of the Mount . . . The world has achieved brilliance without wisdom, power without conscience. Ours is a world of nuclear giants and ethical infants. We know more about war than we know about peace, more about killing than we know about living."

Global Nuclear Arsenal: old numbers

China suspected strategic nuclear weapons: 250 suspected non-strategic nuclear weapons: 120 suspected total: 400 France 350,0,350 India 60,?,60? Israel 100-200,?,200? Pakistan 24-48,?,24-48? Russia -6,000,-4,000,-10,000 UK 180,5,185 US 8,646, 2,010, 10,656

Core of a Nuclear Reactor

Control rod stuck in Kashiwazaki Kariwa unit 19 October 2007 Tokyo Electric Power Company (Tepco) reported that a control rod cannot be removed from the reactor of unit 7 of its Kashiwazaki Kariwa nuclear power plant. The unit shut down automatically when an earthquake struck the plant on 16 July. Silkwood

Medical Uses of Nuclear Technology

Diagnostic Uses of Radioactive Materials: Tracers: bone scans, kidney scans, and others. Radioactive isotopes are used as tracers to identify abnormal bodily processes. This is possible because some natural elements tend to concentrate in certain parts of the body: iodine in the thyroid, phosphorus in the bones, potassium in the muscles. When a patient is injected with a radioactive element, a special camera can take pictures of the internal workings of the organ.

Einstein's formula

E=mc^2, shows that energy and mass are related. you can convert mass into energy -small amount of mass gives a lot of energy -1 gram of mass is equal to 30 tons of TNT -hiroshima or nagasaki bombs were small but still had 20,000 tons of TNT power -eisenhower: "more bang for the buck"

The example of thyroid disease and cancer

Graves' disease, a thyroid condition, can be cured by drinking a form of radioactive iodine that concentrates naturally in the thyroid and destroys the diseased portion. This treatment is so successful that it has virtually replaced thyroid surgery.

Nuclear Reactors

Heat is produced in a nuclear reactor when neutrons strike Uranium atoms causing them to fission in a continuous chain reaction.

Suicide Squad

In CP-1 the handmade wooden rods were wrapped with sheets of cadmium, a metal that hungrily absorbs neutrons. By moving one or more control rods in or out of holes in the pile, allowing the cadmium to absorb greater or lesser numbers of neutrons, Fermi could accelerate, slow, or stop the chain reaction. If something happened to the control rods, he had a suicide squad in reserve: three young scientists with jugs of cadmium-sulfate solution waited near the ceiling of the squash court, ready to flood the pile with cadmium and quench any runaway reaction at the risk of their lives.

The Eastern Front

Japan

Who discovered these 10 missing????

Lise Mitner, Otto Hann, Fritz Stroudsman in 1935 •Lise Mitner escaped to Copenhagen and met up with Neils Bohr •It was ENERGY •Fission -RADIOACTIVITY -First indication that you can generate energy from radioactive fission

Robert Openheimer

Los Alamos, The test bomb, the test

History of Nuclear Technology: 1902

Marie and Pierre Curie isolated a radioactive metal called radium

Students of Rutherford's

Neils Bohr- from sweden, very famous for quantum theories and quantum mechanics William Chadwick -rutherford wanted his student to measure the height of the tower using a barometer (detects pressure)

Worlds Nuclear Reactors

North America: lots Western Europe: west Russia: not too many Asia: eastern South America: not too many 434 in 33 countries

Two nations ended their nuclear programs. What are those nations???

North Korea?

Nuclear Weapons (bombs)

Nuclear bombs have: -A source of fissionable fuel U-235 or Pu-239 -A triggering device -A way to allow the majority of fuel to fission before the explosion occurs (otherwise the bomb will fizzle out)

Structure of an Atom

Nucleus contains two types of particle, protons and neutrons. The properties of the subatomic particles are summarized in the table below. Proton: Particle Mass 1 Charge 1 Neutron: Particle Mass 1 Charge 0 Electron: Particle Mass 1/1840 Charge -1 Protons and Neutrons are in the Nucleus

Rebirth of Nuclear Technology: 2005

On September 22, 2005 NuStart Energy selected Port Gibson (the Grand Gulf site, Mississippi) and Scottsboro (the Bellefonte site, Alabama) for 2 new nuclear units.

Types of Reactors

Pressurized water reactor (PWR) -when pressure increases boiling point increases Boiling water reactors (BWR) *links on slide 46

Nuclear Weapons Stockpiles: Current

Russia: 8500 US: 7,700 France: 300 China: 240 UK: 225 Pakistan: 90-110 India: 80-100 Israel: 60-80 North Korea: <10 Total Nuclear Weapons: 17,300

Spent Nuclear Fuel

Spent Fuel Pools- Currently, most spent nuclear fuel is safely stored in specially designed pools at individual reactor sites around the country. Dry Cask Storage - If pool capacity is reached, licensees may move toward use of above-ground dry storage casks.

Radiation Exposure Limits

Target tissue Regulatory Limit MPD: 1,250 mrem/quarter REHS (NJ) Guidelines: 125 mrem/quarter Extremities 18,750, 1,875 Skin/Other Organs 7,500, 750 Fetus 500, 50

Half Life

The half-life describes the amount of time needed for half of a sample of unstable atoms or particles to undergo decay. Thallium-208, for example, decays into lead-208 with a half-life of 3.05 minutes. This means that half of a sample of thallium-208 will decay into lead-208 over the course of 3.05 minutes.

Communications Breakdown

The test was carried out without a proper exchange of information between the team in charge of the test and personnel responsible for the operation of the nuclear reactor.

Doubling time

The time required for a breeder reactor to produce enough material to fuel a second reactor is called its doubling time, and present design plans target about ten years as a doubling time. A reactor could use the heat of the reaction to produce energy for 10 years, and at the end of that time have enough fuel to fuel another reactor for 10 years.

The pile has gone critical

Through the morning and early afternoon the historic experiment proceeded. By midafternoon, an eyewitness remembers, "suddenly Fermi raised his hand. 'The pile has gone critical,' he announced. No one present had any doubt about it." The reaction had become self-sustaining. The pile's neutron intensity at that point was doubling every two minutes as the chain reaction proceeded. Left uncontrolled for an hour and a half, that rate of increase would have carried CP-1 to a million kilowatts. Nothing very spectacular had happened. Nothing had moved and the pile itself had given no sound. For some time they had known that they were about to unlock a giant; still, they could not escape an eerie feeling when they knew they had actually done it.

Relative Abundance of Uranium Isotopes

U-238 Natural Abundance- 99.27% Half-Life- 4.47 billion years U-235 Natural Abundance- 0.72% Half-life- 700 million years U-234 Natural Abundance- 0.0055% Half-life- 246,000 years

Moderators

Used to slow down the neutrons so that they can interact with the U235 atoms. Heavy water, carbon, etc.

Control rods

When the control elements, or control rods as they are often called, are pulled out of the core, more neutrons are available and the chain reaction speeds up, producing more heat. -when they are inserted into the core, more neutrons are absorbed, and the chain reaction slows or stops, reducing the heat oWhy things don't go bizurk oThey suck up neutrons, take them out of the picture so they aren't available anymore oMade up of cadmium

The EBR-I facility

a National Historic Landmark today (In Idaho). Visitors can see four early nuclear reactors inside. Visible in this photo are two prototype nuclear aircraft engines, built and tested at INEEL but never used in flight.

Control elements

are made of materials that absorb neutrons, are placed among the fuel assemblies. (Cadmium)

DIAGRAM SLIDE 84 upper biological shield

core region (empty), pile of materials thrown from helicopters and possible location of part of the core

Enrico Fermi and Leo Szilard

got a patent in England to utilize the fission process to make energy -use a piece of carbon (graphite)

What comes out of U (fuel) when we do radio dating

heat and neutrons are coming out

Chernobyl Reactor #4 Design

high-power channel reactor- reactor bolshoy moschnosty kanalny **slide 80!!!!!! you have to actually look at these fuel bundles, pressure tubes, control rods, steam separator, steam, turbine, condenser, biological shield, graphite moderation

The problem

how do we tell people who can have nuclear energy and who cant

Causes

lack of a safety culture, design fault in the RBMK reactor, violation of procedures, communications breakdown

Theory of special relativity

matter (mass) and energy were two forms of the same thing E=mc^2

First new nuclear power plant to be built in the US since the 70s

may be installed in the remote town of Galena, Alaska. The town's City Council approved the idea, and Toshiba proposed to install its model 4S "nuclear battery" in Galena free of charge as a test.

1960-1979

opresident wanted to be done with nuclear energy ofrom that point, 1979, there had not been a single reactor in the US o now throughout the world 10% of the energy are provided by nuclear energy AT THIS TIME, france had the highest nuclear energy, 75% of all their energy had come from nuclear sources Baltic states (states around the baltic sea)- lithuania, estonia, latvia- nuclear sources are a big impact as well

Typical Exposure in USA

radon- 54% x-rays- 11% internal- 11% terrestrial- 8% cosmic- 8% nuclear medicine- 4% consumer products- 3% other- 1%

First commercial reactor

shippensburg PA

Atomic Mass

skip

c

the speed of light, 300,000 kilometers per second c^2=90,000,000,000 km^2/s^2

Three years later...

there was another electrifying breakthrough, when Albert Einstein published his theory of special relativity

nuclear fission

they had split an atom into two new atoms -in creating two nuclei from one uranium nucleus, they had transformed part of the original mass into energy--33 years after einstein had said it could be done