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Three Mile Island
Prepared by: Group 2 (4BENC)
Prepared for: Engr. Siva Kumar A/L Subramaniam
Subject: BENU4583 - Engineering Ethic
The nuclear accident case study
Content
Members• Latifah (Leader)• Marhaizan• Sin Ni• Sabta Ali• Basha Abas• Muhamad Syakir• Safiy Hafifi
1. Introduction
2. Violation Code of Ethics
3. Guidance to Prevent The Event From Happening
4. Ethical Theories
5. Analysis of Issues
6. Flowchart
7. What Should People Involved Do Differently?
8. Conclusion
Introduction
• Name of power plant: Three Mile Island Power Plant (TMI)• Location: Susquehanna River in Pennsylvania, USA , 16 km from the state capital, Harrisburg, a city of 90000
• Type of source energy: Nuclear
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• Power capacity: 1, 700 Megawatts or enough to supply 300,000 homes
• Others: TMI consist of two nuclear plants TMI-1 and TMI-2
Nuclear power plants generate electricity by using steam turbines. The function of the nuclear fuel is to heat water and convert it to steam.
Both plants is 900 MW(e) unit with pressurised water reactors designed by Babcock and Wilcox. The second unit of the site started commercial operation on December 30, 1978.
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What happened to TMI-2?
• Accident began about 4.00am on March 28, 1979 when failure in secondary building.
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End of chapter
TMI-2
TMI-1
What happened to TMI-2?
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End of chapter
• Main feedwater pump stop running caused by electrical and mechanical failure
• Pressure in primary system increased• PORV is opened to reduce the pressure by supply the coolant water
from pressurized relief tank• Once the pressure is stabilized, the PORV should closed to stop the
supplied coolant. But it did not
• There for the coolant was suck back to pressurized relief tank and coolant was overflow caused the reactor to overheated• There are no indicator to show the coolant level in reactor core
• Operator just judge the coolant level by level in pressurizer, since was high they assumed the coolant is fully covered
• Instead the core is experiencing a lost of coolant accident• Nuclear fuel overheated, zirconium cladding ruptured fuel pallet
making ½ of core melted• Failure in secondary building
STOP FUNCTIONING
PRESSUREINCREASED
PORVOPENED
PORVFAILED TO CLOSE
PRESSURESTABILIZED
CORE AREEXTREMELY OVERHEATED
Violation Code of Ethics (NSPE)
Engineers shall undertake assignments only when qualified by education or experience in the specific technical fields involved. (2a)• In the case, the operators are not trained to understand the
nature of the PORV indicator and to look for alternative confirmation that the main relief valve was closed. There was a temperature indicator between the PORV and the pressurizer that could have told them the valve was stuck open, but this temperature indicator was not part of the "safety grade" suite of indicators, and the operators had not been trained to use it. It is located at the back of the desk also meant that it was effectively out of the operators’ sight.
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Violation Code of Ethics (NSPE)
If engineers’ judgment is overruled under circumstances that endanger life or property, they shall notify their employer or client and such other authority as may be appropriate. (1a)• In this case, critical human factors problems were revealed in the
investigation about the industrial design of the reactor control system's user interface. A lamp in the control room, designed to illuminate when electric power was applied to the solenoid that operated the pilot valve of the PORV, went out, as intended, when the power was removed. This was incorrectly interpreted by the operators as meaning that the main relief valve was closed, when in reality it only indicated that power had been removed from the solenoid, not the actual position of the pilot valve or the main relief valve. Because this indicator was not designed to indicate the actual position of the main relief valve, the operators did not correctly diagnose the problem for several hours.
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Violation Code of Ethics (NSPE)
Engineers may express publicly technical opinions that are founded upon knowledge of the facts and competence in the subject matter. (3b)• The NRC officials believed (without concrete
analysis) that the hydrogen bubble could explode, through such an explosion was never possible since there was not enough oxygen in the system. They had ordered evacuation and that a meltdown was conceivable.
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End of chapter
Guidance to Prevent The Event From HappeningSection III (9)(e)
Engineers shall continue their professional development throughout their careers and should keep current in their specialty fields by engaging in professional practice, participating in continuing education courses, reading in the technical literature and attending meeting and seminars.
• The TMI management system
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Guidance to Prevent The Event From HappeningSetion III (1)(a)
Engineers shall acknowledge their errors and shall not distort or alter the facts.
• The nuclear power plant’s management should acknowledged their fault on the arisen of misunderstanding problem.
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Guidance to Prevent The Event From HappeningSection II(1)
Engineer shall hold paramount the safety, health, and welfare of the public.
• The NRC has primary responsibility and regulatory authority for health and safety measures as they relate to the operation of commercial nuclear plants.
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End of chapter
Ethical Theories
Utilitarianism Ethics (design deficiency)
• No procedure to identify and manage the meltdown event and the operating staff is not trained for it.
• Global control board weakness in indications of order instead of position without specific warning.
• Existing emergency operating procedure is difficult to use and not suitable.
• The improper maintenance of the pressurizer increased the probability of the malfunction of open valve.
• The closed connecting valves of the steam generators auxiliary feedwater system leads to the complete loss of emergency core cooling system.
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Ethical TheoriesDuty Ethics• NRC officials failed to fulfill their duty – stirred public
fear by making false statement .• The plant operators’ failed to carry out their duty in
handling and mitigating the accident .• The management’s duty is not fulfilled by not providing
proper training to the plant operators (unsystematic management system).
• The local and state authorities’ duty have been carried out by preparing the residents’ evacuation process and cooperate with the NRC authority.
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Ethical Theories
Right Ethics• People that live near the power plant - the right to live in
safe environment.
• The operators’ in the plant - the right to have a safe
working environment and to live.
• The local and state authorities’ right – defend population
safety by questioning nuclear power plant’s safety
procedure.
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Ethical TheoriesVirtue Ethics• The plant operators’ incompetency in accident handling
and not able to make wise decision.
• The power plant’s management does not carry out their
responsibility by ignoring operators’ training which is the
main element in preventing accident.
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End of chapter
Analysis of IssuesFactual issue:
1. TMI-2 reactor's fuel core.2. Gas in containment building was move to waste
gas decay tanks.3. Hydrogen gas is created because chemical
reaction between water and the zircaloy metal. 4. No injuries or obvious health impacts.5. Major of health studies has been conducted since
the accident happened.6. Communications problems.
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Analysis of IssuesConceptual issue:
1. No "China Syndrome" 2. Nuclear Regulatory Commission (NRC)
statement.
Moral issue:
3. Better understanding on the safety nuclear energy.
4. Public awareness increase. 5. Operators disability in making wise decision.
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End of chapter
Flowchart
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Continue
Flowchart
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End of chapter
From previous
What Should People Involved Do Differently?All the people involved in the accident should have done differently in avoiding the accident from happen in the plant, as described below:• Engineers – Participate with continuing education
course and seminars• Management - Identify workers performance, staffing
requirements, revamping operator training, improved instrumentation and controls
• Government – Strengthen and reorganize the safety enforcement.
• Local authority – Enhance emergency respond team.
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End of chapter
ConclusionC
ontent
End of chapter
Accident was caused by EQUIPMENT failure and HUMAN ERROR
to handling the situation
Accident was caused by EQUIPMENT failure and HUMAN ERROR to handling
the situation1 LOSS of coolant to the reactor led to producing heat and melting the fuel
rod. Small amount radioactive RELEASED to
environment
LOSS of coolant to the reactor led to producing heat and melting the fuel rod. Small amount
radioactive RELEASED to environment2But, NO injuries or deaths involved in this accident
and the experts concluded the amount of radioactive
released is NOT hazardous to living thing
But, NO injuries or deaths involved in this accident and the experts concluded the amount of radioactive released is NOT hazardous to living
thing3
To cleanup cost around a BILLION dollars to
company and took almost 10 YEARS to complete
To cleanup cost around a BILLION dollars to company and took almost 10 YEARS to
complete4
After incident, NO new reactors to be built and
leads to a very large evolution to the SAFETY IMPROVEMENT of a
majority of nuclear plants.
After incident, NO new reactors to be built and leads to a very large evolution to the SAFETY
IMPROVEMENT of a majority of nuclear plants.
5
Today, nuclear reactors are still important for our
source of energy, but they are SLOWLY becoming
decommissioned until find a secure way to handling
nuclear energy
Today, nuclear reactors are still important for our source of energy, but they are SLOWLY
becoming decommissioned until find a secure way to handling nuclear energy
6
Thank You
The Three Mile Island AccidentBy Group 2 (4BENC) 2010/2011 UTeM