JH - NEBOSH - IOG - Questions - Master Set
Identify the hazardous properties of Liquid Petroleum Gas (LPG).
hazardous properties of Liquid Petroleum Gas - LPG Heavier than air Vaporisation - Cold Storage - Leaks Fire / Explosion
Outline the meaning of `as low as reasonably practicable' - ALARP
"ALARP" is short for "as low as reasonably practicable". ALARP involves weighing risk against the trouble, time and money needed to control it. Thus, ALARP describes the level to which we expect to see workplace risks controlled. ALARP allows us to set goals for duty-holders It is a key part of the general duties of the Health and Safety at Work Act 1974 ALARP is about weighing the risk against the sacrifice needed to further reduce it To spend £1m to prevent five staff suffering bruised knees is obviously grossly disproportionate But To spend £1m to prevent a major explosion capable of killing 150 people is obviously proportionate
Outline how a Boiling Liquid Expanding Vapour Explosion (BLEVE) occurs
"BLEVE" is an acronym for "Boiling Liquid Evaporating Vapor Explosion" and involves a situation where. a liquid in a container - often a compressed liquid such are propane suddenly fails, resulting in a rapid expansion of the liquid into a vapor, releasing energy that is capable of hurtling parts of the tank or other nearby objects for considerable distances. If an ignition source is present and the vapor is flammable, a sudden deflagration (fire) or explosion may occur, further increasing the energy of the sudden vapor release, and causing the creation of a fireball that releases a sudden burst of radiant (heat) energy. The largest documented BLEVE explosions (usually involving propane or similar substances) have resulted in numerous deaths, some at great distances from the initial explosion (hundreds of feet or more) from either propulsion of debris, exposure to radiant heat, or a combination of both.
In relation to Hydrocarbon Vapour Clouds Define what is meant by: BLEVE's
"BLEVE" is an acronym for "Boiling Liquid Evaporating Vapour Explosion" It is an explosion caused by the rupture of a vessel containing a pressurized liquid above its boiling point.
Identify the information that might be included on a checklist for an investigation following an accident
1. Obtain basic facts: Names of injured Witnesses Place Date and time Persons in area Ascertain substances / chemicals involved Injuries Damage to equipment 2. Establish circumstances: What happened? Causes Events leading to incident Competence Supervision Behavior 3. Preventive Measures - Review the risk assessment for the activity: What precautions should have been in force? What training should those carrying out the activity have received? What precautions were actually taken? Compare them with those which should have been taken. What training was actually given? Compare it with training which should have been given. 4. Was the initial response adequate?: Firefighting First aid Containment and spillage 5. Identify underlying causes: Management or supervision failure? Lack of competence? Inadequate training? Shortcomings in original design of Equipment Facilities Absence of a system for maintenance. 6. Determine action needed to prevent a recurrence Improve physical safeguards Introduce better test and maintenance arrangements Improve work methods, Provide and use personal protective equipment Make changes to supervision and training arrangements, Review procedures involving outside contractors Improve inspection systems
Outline the term Major Accident
A Major Accident Is: An unplanned event with potential for multiple fatalities and or serious damage, possibly beyond the asset itself. Typically these are hazardous releases, but also include major structural failure or loss of stability that could put the whole asset at risk. ----------------------------------------------------------------------------- 1. A fire, explosion or other release of a dangerous substance involving death or serious personal injury to persons on the installation or engaged in an activity on or in connection with it 2. Any event involving major damage to the structure of the installation or plant affixed thereto or any loss in the stability of the installation; 3. The failure of life support systems for diving operations in connection with the installation, the detachment of a diving bell used for such operations or the trapping of a diver in a diving bell or other subsea chamber used for such operations 4. Any event arising from a work activity involving death or serious personal injury to five or more persons on the installation or engaged in an activity in connection with it
A distillation column requires protection from fire exposure through active or passive fire protection. Outline how a fixed water deluge system could provide fire
A fixed water deluge system could provide protection for a distillation column by extinguishing the fire, controlling the fire or by providing protection for the adjacent distillation columns with the cooling effect the fixed water deluge system provides
A distillation column requires protection from fire through passive and active fire protection. (a) Outline how a fixed water deluge system could provide fire protection (2) (b) Identify two additional examples of active fire protection. (2)
A fixed water deluge system could provide protection for a distillation column by extinguishing the fire, controlling the fire or by providing protection for the adjacent distillation columns with the cooling effect the fixed water deluge system provides. Water mist systems and a Firewater monitor and hose-reels
Identify the categories of staff who might be considered useful members of an internal accident investigation team
A simple investigation might be carried out by the line manager of the area; a more detailed investigation often involves a team of investigators that might include. A safety specialist Senior managers A technical specialist A worker representative Offshore investigating teams may also include installation specialists from services such as drilling, well services, maintenance, process, and deck crews.
Outline the actions that should be taken by a person upon discovering a fire
Actions that should be taken by a person upon discovering a fire: Call Alarm Call emergency services Isolate any gas/ hydrocarbon supplies if possible Evacuate area
A pump containing flammable corrosive slurry has been stopped for maintenance. An operator will prepare the pump for maintenance using a nitrogen supply, drain header and collection vessel. Using this information; Outline EIGHT risks to the operator when preparing the pump for maintenance.
Asphyxiation due to displacement of 02 Fire Explosion Irritant/Corrosive substance Incorrect isolation of valves Incorrect Lock Out/Tag Out system Lack of gas monitoring Burst pressure lines causing injury
Identify four parties, other than the employer, who may want to investigate these types of incident
Authorities Insurance Companies Manufactures Suppliers
Brittle fracture.
Brittle fracture: Rapid run of cracks through a stressed material with plastic deformation before failure caused by such things as repetition of inappropriate heating or pressurising rates
Buncefield Incident: Causes:
Buncefield Incident Causes: A fill level gauge and high fill level alarm failed Fuel storage tank overfilled Fuel leaked out of the vents at the top of the storage tank into the bund This resulted in a Vapour Cloud The vapour cloud flowed offsite Ignition leading to the vapour cloud explosion took place at a pump house
Buncefield Lessons learned
Buncefield Lessons learned: Need for back-up systems/processes for safety critical devices Bunds/containment walls to be designed to withstand heat/explosion Importance of coordinated response & emergency planning Business/Disaster interruption and or recovery plan Dealing with media after the incident.
In relation to Hydrocarbon Vapour Clouds Define what is meant by: CVCE's
CVCE - Confined Vapour Cloud Explosion Explosion of a liquefied hydrocarbon or other flammable gas cloud in a confined Space, such as vessels, pipelines, buildings
Give the meaning of the classification "Carcinogenic"
Carcinogenic - Can induce the growth of malignant tumours
Following an annual shutdown of a process plant Outline the operational control measures that could minimise the risk of an incident before filling equipment in preparation for start-up
Control system - process controls intelligent alarms Suitable procedures and methods Trained and competent employees Suitable supervision of the operation Detection systems- flow/ no flow/ overflow Zone controls Use of flares / over flow / over pressure devices Maintenance and integrity of systems Management of overrides
Identify the controls available to maintain Safety Critical Equipment
Controls available to maintain Safety Critical Equipment Process Control Systems Process and Emergency Shutdown systems Fire and Gas Systems Drilling Control systems
Outline the following failure modes that may lead to loss of hydrocarbon containment from storage tanks/vessels or pipelines Creep
Creep: Is slow movement under stress, made more severe with heat for long periods, especially with increases in temperature approaching melting points.
Outline the contents of a typical permit-to-work
Date & Time Description of the task to be carried out Work location Duration of permit Potential Hazards Isolations that have been made Precautions that are needed (ppe rpe etc) Details of the person authorising the work Signature of the worker carrying out the work Risk Assessment / JSA number Details of when the permit is revoked or finished
An employee was seriously injured in an accident at work within an oil and gas installation. Identify the documented information that might be used by the investigating team to determine the causes of this acciden
Documented information that might be used by the investigating team to determine the causes of an accident; PTW Photographs CCTV Footage Witness Statements Previous Health and Safety Meeting Minutes Risk Assessments / JSA's Method Statements Control Room Data Internal incident report forms Maintenance records Disciplinary records Safe systems of work Audit / inspection reports SOP's D & A Test results
Many major oil / gas incidents have occurred in recent years, eg Piper Alpha, Texas City, Mumbai High. Outline reasons why such incidents should be investigated by employers.
Establish the Chain of Events Establish Causes of incident Establish Route Cause Establish process failures Establish Lessons learnt to prevent similar occurrences
Outline FOUR control measures to reduce the risk to workers exposed to the sludge.
FOUR control measures to reduce the risk to workers exposed to LSA sludge; Wearing of correct PPE - Respirator Monitoring devices and personal sensors Explosion proof certified equipment Safety procedures Training
An operator is draining a flammable liquid from process pipework to a metal container. The supervisor is concerned about the possibility of an electrostatic charge forming and stops this operation until a risk assessment is undertaken. During this work activity: Identify factors that influences the generation of the electrostatic charge;
Factors that influences the generation of the electrostatic charge: Hot Dry Weather Flow rate, Overfilling Lack of earthing / bonding Liquid instability Splash Filling None Conductivity of materials Agitation Filters Pressure Velocity
An oil and gas industry employer is reviewing tendering contracts for an offshore platform modification. Identify the factors that should be considered when assessing the health and safety competence of a contractor.
Factors that should be considered when assessing the health and safety competence of a contractor: HSE Policy's Certifications - Accreditations Commitment to HSE from senior management and how this is demonstrated - Safety Management system and implementation - Safety tools used Project records - track record of similar projects Safety Statistics - KPI's records and achieved Risk Management system and procedure Previous incident investigations reports Competency of employees and project staff Safety Initiatives used with in the business and project
What are the four main areas detailed and explained in a Permit to Work
Permits to work detail and explain: The work involved The isolations required Hazards in the work to be carried out Precautions to avoid injury
During an inspection an external fuel storage tank is found without a bund. Outline the features which should be included in the design of a tank bund
Features which should be included in the design of a tank bund: Ensure the maximum quantity of product can be contained within the bund at least 110% Make allowance for the space occupied by other tanks Located away from traffic routes Impermeable base No drain valve- rain water should be pumped out Lightening protection
A distillation column requires protection from fire exposure through active or passive fire protection. Identify TWO examples of passive fire protection.
Fire Walls Fire doors Fire resistant coatings Thermal insulation
A distillation column requires protection from fire exposure through active or passive fire protection. Outline why the metal legs of the column should be protected.
Fires can cause thermal weakening of steelwork and result in the collapse of structures, failure of equipment, and subsequent escalation of the initial event.
Identify the three classifications within flammability
Flammability falls into three distinct classifications: Extremely Flammable - Flash point below 0 Celsius. Highly Flammable - Flash point between 0 and 21 Celsius. Flammable - Flash point between 22 and 55 Celsius.
Give the meaning of the following term Flashpoint
Flashpoint is the lowest temperature at which sufficient vapour is given off to "Flash" - that is, ignite momentarily, and not carry on burning, when a source of ignition is applied to the vapour.
Outline the term Flash Point
Flashpoint is the lowest temperature at which sufficient vapour is given off to "Flash" - that is, ignite momentarily, and not carry on burning, when a source of ignition is applied to the vapour. At the flash point the application of a naked flame gives a momentary flash rather than sustained combustion, for which the temperature is too low
Identify THREE suitable types of portable extinguisher
Foam Dry Powder C02 Carbon Dioxide
Other than a fixed water deluge system Identify TWO additional examples of active fire protection
Foam Systems Water Mist Systems
Outline the fire protection that would be used on a floating roof tank
For floating roof tanks the main means of fire protection is to use fixed foam installations which spread foam around the rim seal. Monitors and water deluge cooling sprays may also be used
On an oil processing plant outline how activation of an H2S detection system, linked to a control room, could prevent a fire.
H2s is a flammable gas, detectors can be used to trigger alarms, control room operators can implement process control measures, emergency procedures, shutdowns or evacuations, activate fire protection systems, and shut down any sources of ignition remotely. This can provide an early warning of a problem and help to ensure people's safety
HAZOPS HAZAN's HAZID
HAZOPS = Hazardous Operations Study HAZAN's = Hazard Analysis HAZID = Hazard Identification
List the Hazards associated with LNG
Hazards associated with LNG; Fire and explosion Pool Fires Bleve's & Vapour Cloud Explosions Explosion in confined space Cold Burns Asphyxiation in a confined space Terrorism
List the Hazards associated with LPG - Liquid Petroleum Gas (Propane/Butane)
Hazards associated with LPG - Liquid Petroleum Gas (Propane/Butane) Highly Flammable Fire & explosion Cold Burns, Frostbite - In its Liquid form Bleve's Pool Fires
Following preparation of a vessel for maintenance within an oil and gas installation a low specific activity - LSA - radioactive sludge was encountered Identify hazards associated with the sludge
Hazards associated with LSA, radioactive sludge; Risk of fire, explosion. Toxicity to Divers
Give the meaning of the following term Highly flammable liquids
Highly flammable liquids Liquids with a flash point below 32°C. Substances which, when hot, catch fire in contact with air at ambient temperature without any energy input
Outline FOUR types of work activity associated with an oil platform that might require permit to-work AND give a reason in EACH case for the requirement.
Hot Work Hot Work Permits are generally applied to any type of work, which involves actual or potential sources of ignition, and work for which there may be a risk of a fire and/or explosion, or which involves the emission of toxic fumes from the application of heat. Cold work Cold work shall include but not be limited to the following: scaffolding, cleaning, over side working, painting Confined space entry A confined space is any vessel, enclosure or compartment large enough to take a person where the atmosphere may be dangerous or incompatible to a person entering because of flammable/toxic gases and other substances or oxygen deficiency. Isolation An Isolation Certificate is required before any work can be started on process, mechanical or electrical plant or equipment. An Isolation Certificate is also required where access to the site of work is restricted or its safety is jeopardized by any adjacent plant or equipment. An activity cannot commence until all the necessary isolation requirements are in place Diving Diving certificate can be used to control the diving activity itself and to ensure that there are no other activities taking place nearby which create unnecessary additional risks e.g. over-side work, live firewater intake pumps.
Outline how the contents of a hot work permit are different to a typical permit-to-work
Hot Work permits would vary as hot works may ignite flammable materials. These would need to be eliminated or removed (preferable) or protected Control of ignition sources through damping down or fire blankets Firefighting equipment has been checked and placed on location together with trained personnel. Gas test details must be included. Additional PPE appropriate to task to be used in addition to the daily mandatory PPE as part of the special precautions to be indicated on the hot work permit.
Identify the key stages of a workplace risk assessment
Identify the hazards Decide who might be harmed and how Evaluate the risks and decide on precaution Record your findings and implement them Review your assessment and update if necessary
Identify four ignition sources that could arise from maintenance or operations on an installation.
Ignition sources are (select four) Electrical equipment: Routinely inspect and test to prevent faults developing that could cause sparks and overheating. Hot work: Welding, burning, etc. - control with a permit-to-work when done in sensitive areas. Smoking: Control and limit to restricted areas on site (welfare areas). Cooking and heating appliances: Locate safely, confine to a galley offshore and use carefully. Mechanical heat (overheating): Control by good maintenance programmes. Deliberate ignition: Prevent by good security, perimeter fences (onshore), CCTV and security lighting.
What are the two categories of immediate cause of accidents/incidents
Immediate causes are the unsafe acts and unsafe conditions that gave rise to the event itself. These will be the things that occurred at the time and place of the accident. For example a worker slips on a patch of oil spilt on the floor Immediate causes: The slip hazard = unsafe condition The worker walking through it = unsafe act
Give the meaning of the following term Lower flammable limit LFL
LFL - The minimum concentration of fuel in air that is sufficient to allow combustion to occur. Bellow the LFL, the mixture is too lean to burn.
Many serious accidents or incidents, including the Piper Alpha disaster in 1988, involve root causes associated with shift handover. An outgoing operator is handing over to an incoming operator at the end of a shift. Outline the main operational issues communicated at shift handover
Main operational issues communicated at shift handover include: Operational status of the installation or process Maintenance completed Maintenance still ongoing Maintenance planned during on-coming shift Routine operation for next shift Updating PTW's - Closed out or still open Any events that happened during the out-going shift, Emergencies, incidents, accidents, breakdowns, plant overrides. Situations where safety systems have been overridden e.g. fire deluge system switched to manual operation Planned events during oncoming shift, shutdowns, drills exercises Operational issues that will occur during the on-coming shift Changes in plant parameters
Identify three marine hazards associated with all types of Floating Platform Storage Offloading Units -FPSO's
Marine hazards associated with all types of Floating Platform Storage Offloading Units -FPSO's Flaring near production area Crew transfer Weather Environmental impact Transferring oil to tanker vessels Risk of collision from sea going vessels Supply/logistics difficulty Pirates Terrorists Spillage damage to marine life
Distinguish between primary, secondary and tertiary offshore evacuation methods
Offshore evacuation methods are: Primary Method: The usual none-emergency method, e.g. ship. Secondary method: Used when the primary method is unavailable, e.g. lifeboat launched from the rig. Tertiary Method: Heavily reliant on the individuals own effort and used as a last resort when all other methods are unavailable, e.g. putting on lifejackets and survival suits and jumping into the sea.
Describe the difference between active and passive fire protection measures
Passive Fire Protection: Is predominantly thermally insulating design elements that are put and left in place, like fire barriers, fire resistant coatings and cladding. They help stop escalation of the fire and protect routes. Active Fire Protection: Means measures that are brought into play when a fire is detected, in order to actively tackle/extinguish the fire, e.g. fixed sprinkler installations, hoses and monitors
Identify the physical consequences of vapour cloud explosions
Physical consequences of vapour cloud explosions; Overpressure Fire & explosion Resulting debris as airborne missiles
A large oil company is proposing to build a new oil and gas installation in the North Sea. The Process Safety Management Team is analysing past incidents and database records from the Oil and Gas Industry. Excluding active and passive fire protection systems, outline physical design features of the platform that would minimise risk to operating personnel in the event of a major incident
Physical design features of an offshore platform that would minimise risk to operating personnel in the event of a major incident: Plant separation Compartmentalisation Protection of personnel / equipment Means of escape Blow out panels Temporary refuges with communications & control
Outline physical design features of an oil and gas installation that would minimize risk to operating personnel in the event of a major incident
Physical design features of an oil and gas installation that would minimize risk to operating personnel in the event of a major incident: Temporary Refuge Routes to and from the TR Means of evacuation from these points Facilities within the TR for monitoring and control of the incident and organizing evacuation
Piper Alpha accident; How it happened and what course of actions were taken to prevent recurrence, Lessons learned.
Piper Alpha Facts: Fire Explosion knocked out fire proof - not Blast proof - walls Control room damaged in 1st blast Initial fire could have been extinguished Fire pumps were set to manual Lifeboats all in one location and could not be reached from accommodation block Other platforms did not shutdown instead continued pumping hydrocarbons to Piper Alpha, increasing the fire
Piper Alpha Failures
Piper Alpha Failures: Permit to Work System -two permits issued for same task Platform layout Delayed decision making Lack of training Active fire system set from Auto to Manual Passive fire protection Lifeboats Communications/Shift Handover
An operator is draining a flammable liquid from process pipework to a metal container. The supervisor is concerned about the possibility of an electrostatic charge forming and stops this operation until a risk assessment is undertaken. During this work activity: Outline practical ways of minimising the formation of an electrostatic charge.
Practical ways of minimising the formation of an electrostatic charge: Humidification of the atmosphere Antistatic additives Reduce flow velocity Intrinsically safe equipment Bonding & Grounding of equipment & containers Avoid splash filling by submerging the fill pipe bellow the liquid level in the container Increasing the conductance of floors, footwear
Large quantities of hydrocarbons are contained in a process plant, with the risk of gas release and explosions. Identify process safety control measures that would minimise the risk of an explosion
Process safety control measures that would minimise the risk of an explosion: Gas detectors Zoning Passive Fire Protection systems Structural Fire Protection systems Fire Detection Systems — Heat detectors; Flame detectors; Smoke detectors; Duct Sampling; Acoustic detectors Process safety systems and controls; flares and vents
A worker has requested a permit-to-work in order to replace damaged thermal insulation in an overhead pipe rack that runs between two plants Outline control measures that should be implemented to reduce the risks to the worker
Risk assessment/JSA for job PTW communicated to and posted in adjacent plant Close communication between adjacent plants Individual Fall Protection
Outline the risks associated with Liquid Petroleum gas LPG.
Risks associated with Liquid Petroleum gas LPG. Asphyxiation Burns (Hot and Cold) Fire / Explosion
Explain the meaning of the term safe isolation
Safe Isolation The interruption, disconnection and separation of all the equipment's motive power sources in such a way that this disconnection and separation is secure by lockable means.
Identify four areas other than electricity where a safe isolation procedure might be used
Safe isolation systems are concerned with the safe isolation of (only four required) Hydraulic (oil) power Pneumatic power and stored energy Residual energy Combustion engines Natural gravitational forces/weight Steam or high-pressure water systems Any combinations of or additions to the above
How is safe isolation, stoppage, draining down and blanking of systems assured during a shut-down
Safe isolation, stoppage, draining down and blanking of systems during a shut-down is assured by: It is vital for the safety of maintenance personnel that services are stopped, isolated, drained down, blanked etc. and remain in a safe condition for the duration of the work. This is ensured by the work being carried out under the controls of a permit-to work. The permit will have a completion section to ensure that all systems are put back into operable condition before start-up, to protect maintenance and operations personnel
Identify suitable controls that minimize risk when operating Floating Platform Storage Offloading Units - FPSO's
Security & surveillance
Outline operational control measures that could minimize the risk of plant damage or injury during start-up or shutdown of a process
Shutdown: Ensure work carried out under the controls of a PTW All services are; Stopped Isolated Drained down Blanked Empty & drain hydrocarbon facilities, with all liquids, gases and residues removed leaving the plant safe to work on Eliminate or control ignition sources Suitable supervision of the operation Certification of items that have been maintained or replaced Start-up: Establish all isolations reconnected, all blanks removed Ensure all safety systems are operational Ensure all systems are tested before start-up Complete PTW Emergency plan - in place
What are the four steps in the investigation process
Step 1: Gather factual information about the event. Step 2: Analyse that information and draw conclusions about the immediate and root causes. Step 3: Identify suitable corrective measures. Step 4: Plan the remedial actions.
Stress corrosion cracking;
Stress corrosion: Occurs under tensile stress and is worse in a corrosive environment at elevated temperatures.
Identify TWO ways in which vapour clouds can be generated
Sudden depressurization Rupture of vessel Loss of containment Uncontrolled buildup of pressure
Identify suitable control measures to minimise the risk to employees using mechanical land transport
Suitable working hours - rest periods Suitable maintenance of vehicles Basic vehicle checks such as lights, tyre pressures Maintain speed limits Wear Seat belts Correct loads and security of loads Chemical and Hazardous material controls Training of drivers Traffic routes and plans GPS tracking systems
Identify THREE properties of Hydrogen Sulphide - H2S
THREE properties of Hydrogen Sulphide - H2S Highly toxic Flammable gas Heavier than air and hence tends to accumulate in low-lying areas Pungent, smells like rotten eggs but rapidly destroys the sense of smell
Large quantities of hydrocarbons are contained in a process plant, with the risk of gas release and explosions Identify THREE types of fire or explosion that could occur
THREE types of fire or explosion that could occur; "BLEVE" Boiling Liquid Evaporating Vapor Explosion" CVCE's Explosion of a liquefied hydrocarbon in a confined space UVCE's Unconfined Vapour Cloud Explosion
Process modules in an oil and gas installation often contain computer rooms that require fire protection Identify TWO examples of fire extinguishing media that could be used in a computer room.
TWO examples of fire extinguishing media that could be used in a computer room: Carbon Dioxide (C02) Dry Chemica
Identify TWO examples of fire protection systems used on floating roof tanks
TWO examples of fire protection systems used on floating roof tanks: Fixed foam systems Portable foam firefighting systems Hose lines
Identify TWO other pieces of workplace equipment where the sludge may be found.
TWO other pieces of workplace equipment where the sludge may be found; Shale Shakers Mud Pits
During an inspection an external fuel storage tank is found without a bund. Identify TWO reasons for providing a tank bund.
TWO reasons for providing a tank bund: Prevent a potential leak causing environmental damage Control any leak within a known area Ensure the maximum quantity of product can be contained within the bund
What is the Dow Fire and Explosion Index
The Dow Fire & Explosion Index is a rapid hazard assessment method for use on chemical plant during process and plant development, and in the design of plant layout
Describe the Key Principles of Safe Shift Handover
The Key Principles of Safe Shift Handover are: A formal procedure High priority conducted Face to Face Two way communication, with both parties taking joint responsibility Both verbal & written communication Based on the analysis of the needs of incoming staff Given as much time as necessary Provide as much, information as necessary
What are the conditions necessary for stress corrosion cracking to occur
The criteria necessary for stress corrosion cracking to occur are: A susceptible material A corrosive environment Enough tensile stress to induce the condition
What are the main dangers associated with LPG
The dangers of LPG lie with its flammability and explosive properties, and the fact that it is stored under great pressure, and hence very low temperature, to retain its liquid state. On release, LPG reverts to its gaseous state, with rapid and considerable increase in volume.
Give a brief summary of the emergency command structure for offshore installations
The emergency command structure for offshore installations. In such circumstances the Offshore Installations Manager OIM is in overall charge. They will be assisted by two on-scene commanders, one from drilling and one from process, a permit controller, a radio operator and an Offshore Installation Supervisor OIS.
During an inspection an external fuel storage tank is found without a bund wall: Identify the environmental effects if a tank failure occurred;
The environmental effects if a fuel storage tank failure are: Oil contamination of ground would be highly toxic to plant and animal life and could enter rivers and waterways depriving life of oxygen
Petroleum storage tank fires have been reduced substantially by using floating roofs, but a fire risk may still exist. Outline how a fire risk may exist with floating tanks
The following fire risk may exist with floating tanks: Lightning strikes Leaks due to corrosion, damaged pipe work Product overfill or high internal pressures Rainwater or snow load sinks the roof and exposes fuel vapours
What main areas does a safety case/safety report cover
The main areas a safety case/safety report cover Identification of major accident hazards. Evaluation of major accident risks and measures taken (or to be taken) to control those risks. Arrangements for audit and audit reports. Confirmation that an adequate safety management system is in place. Major accident prevention policies. Identification of the safety critical elements in place to manage major accident hazards. Details of the emergency plan.
Outline the tiered, three-level approach to emergency medical treatment
The tiered three-level approach to emergency medical treatment is: Level 1 - Basic first-aid Intended as first line treatment to preserve life and stabilise the injured: Requiring the provision of an adequate number of trained first-aiders (depending on the level of risk, number of workers, installation remoteness, etc.) and first-aid equipment (first-aid kits etc.). Level 2 - Advanced first-aid Requiring first-aiders with more advanced skills (such as the use of specialised equipment or methods). Level 3 - Utilising medics or paramedics With remote support from other medical professionals, who will have specific medical training and be capable of administering drugs, advanced wound treatment, etc
Identify the factors to be considered when assessing the health and safety competence of a contractor.
There are many factors that have to be considered when assessing the health and safety competence of a contractor. One important factor is the contractor's experience and training, both in the type of oil and gas process that they will be working on and offshore safety requirements. Whether the contractor has a health and safety policy in place, supported by the necessary organisation and arrangements, and the quality and extent of risk assessments carried out are also significant points to look for. The contractor's recent health and safety performance (including any accident history) should be reviewed, as well as establishing whether any enforcement action has been taken against the contractor. Evidence should be requested of the availability of suitable, up-to-date method statements; arrangements to monitor health and safety and carry out site inspections; qualifications; training records and skills cards carried by workers; and membership of professional bodies or trade associations. Proof of the contractor having employer's liability and public liability insurance is an important factor, and references should be available from previous clients. Finally, it is important to take into consideration arrangements for the selection and appraisal of any subcontractors and how liaison with the contractor is going to take place.
Outline why it might be important to plan the route of a road tanker carrying dangerous goods.
There are two basic reasons why it might be important to plan the route of a road tanker carrying dangerous goods. Not all roads are suitable for tankers - narrow roads, weak bridges. The security threat (terrorism, theft) to the valuable load being carried and its possible use as a terrorist weapon.
Thermal shock;
Thermal shock: Cracking associated with rapid temperature change with different parts of an object expanding by different amounts where the stress overcomes the strength of the materials.
Why are accident investigations carried out
To identify the immediate root causes of the incident - incidents are usually caused by unsafe acts and unsafe conditions in the workplace, but these often arise from underlying root causes. To identify corrective actions that will prevent a recurrence - The main reason for investigating
Outline the types of failure mode of storage tanks that may lead to loss of containment from hydrocarbon
Types of failure mode of storage tanks that may lead to loss of containment from hydrocarbon： Overfilling Corrosion Construction fault Design Fault Bund Failure Operator / Instrument Error Tank not tested Foundations Overload Vacuum effect during emptying of tank
Give the meaning of the following term Upper flammable limit - UFL
UFL - The maximum concentration of fuel in air that is sufficient to allow combustion to occur. Above the UFL the mixture is too rich to burn
In relation to Hydrocarbon Vapour Clouds Define what is meant by: UVCE's
Unconfined Vapour Cloud Explosion Explosion of a liquefied hydrocarbon in a unconfined space. Such as a fuel leaking from a Storage facility, e.g. Buncefield incident
Outline how a vapour cloud explosion can be generated
Vapour cloud explosion can be generated by; Confined / unconfined generation Vapour cloud explosions may arise from vaporization of a release of liquefied gas from a ruptured vessel or pipeline
In relation to fire protection, outline the principle of operation of a voting system and when it might be used.
Voting systems are used in order to minimise false alarms, in cases where activation has consequences such as shutting down production (you don't want that unless it is absolutely necessary as it will cost significant time and money). The principle of operation is that more than one detector in a set must be triggered and it is in this sense that it is called a "voting" system. They can be set to different sensitivities depending on the risk - typically two out of three
Identify different ways in which an alarm may be raised in the event of a fire in a building
Ways in which an alarm may be raised in the event of a fire in a building: Manually Automatically Visually Verbally
Oil and gas installations use water for cooling and heating although it can be a hazard in some situations. Identify risks with water AND give a practical example in EACH case
When stored under pressure as in Fire lines and steam water lines May contain bacteria if not circulated e.g. dead end pipe legs May cause an unstable reaction when mixed with some hydrocarbons
A worker has requested a permit-to-work in order to replace damaged thermal insulation in an overhead pipe rack that runs between two plants. Identify THREE hazards associated with this activity
Working at height SIMOPS
Large quantities of hydrocarbons are contained in a process plant, with the risk of gas release and explosions. Identify the zone classifications relating to flammable atmospheres
Zone 0 - Area where an explosive gas atmosphere is present continuously or for long periods Zone 1 - Area where an explosive atmosphere is likely to occur in normal operations Zone 2 - Area where an explosive atmosphere is not likely to occur in normal operations — if it occurs will only exist for a short time
List the three hazard zones and the categories of electrical equipment to be used in each zone
Zone 0 or Zone 20 = Category 1 equipment Zone 1 or zone 21 = Category 1 0r 2 equipment Zone 2 or Zone 22 = Category 1, 2 or 3 equipment
