
This diagram demonstrates the
defense in depth strategy of design of modern
nuclear power plants. Current plants may have some or all of these defenses, the defenses vary depending on the type of plant, the nation constructing them, the use (civilian, military, naval vessels) and the age.
''1st layer'' of defense is the inert,
ceramic quality of the
uranium oxide itself.
''2nd layer'' is the air tight
zirconium alloy of the
fuel rod.
''3rd layer'' is the
reactor pressure vessel made of steel more than a dozen centimeters thick.
''4th layer'' is the pressure resistant, air tight
containment building.
''5th layer'' is the
reactor building or in newer powerplants a second outer containment building.
'Nuclear safety' covers the actions taken to prevent
nuclear and radiation accidents or to limit their consequences. This covers
nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, the use and storage of nuclear materials for medical, power, industry, and military uses. In addition, there are safety issues involved in products created with radioactive materials. Some of the products are legacy ones (such as
watch faces), others, like
smoke detectors, are still being produced.
Nuclear weapon safety, as well as the safety of military research involving nuclear materials, is generally handled by separate agencies than civilian safety, for various reasons, including secrecy.
Agencies
Many nations utilizing
nuclear power have special institutions overseeing and regulating nuclear safety.
Internationally the
International Atomic Energy Agency "works for the safe, secure and peaceful uses of nuclear science and technology."
Civilian
nuclear safety in the U.S. is regulated by the
Nuclear Regulatory Commission (NRC). The safety of nuclear plants and materials controlled by the U.S. government for research, weapons production, and those powering naval vessels, is not governed by the NRC.
[1][2]
In the UK nuclear safety is regulated by the
Nuclear Installations Inspectorate (NII) and the Defence Nuclear Safety Regulator (DNSR).
Key concepts
★
Safety culture
★
Redundancy
★
Common mode failure
★
Passive nuclear safety
★
Active safety
★
Defence in depth
★
Containment building
★
Ionising radiation protection
★
Nuclear criticality safety
★
Reactor Protective System (RPS)
★
Conflict of interest
Concerns
★
Criticality accidents
★
Loss-of-coolant accident (LOCA)
★
Nuclear fuel response to reactor accidents
★
Nuclear meltdown
★
Radioactive contamination
★
Radioactive waste
Risk assessment
★
International Nuclear Events Scale
★
Probabilistic risk assessment
★
★ ''Severe Accident Risks: An Assessment for Five U.S. Nuclear Power Plants''
NUREG-1150 1991
★
★ ''Calculation of Reactor Accident Consequences''
CRAC-II 1982
★
★ Rasmussen Report: ''Reactor Safety Study''
WASH-1400 1975
★
★ The Brookhaven Report: ''Theoretical Possibilities and Consequences of Major Accidents in Large Nuclear Power Plants''
WASH-740 1957
The
AP1000 has a maximum core damage frequency of 5.09 x 10
-7 per plant per year. The
European Pressurized Reactor (EPR) has a maximum core damage frequency of 4 x 10
-7 per plant per year.
[3] General Electric has recalculated maximum core damage frequencies per year per plant for its nuclear power plant designs:
[4]
:BWR/4 -- 1 x 10
-5
:BWR/6 -- 1 x 10
-6
:
ABWR -- 2 x 10
-7
:
ESBWR -- 3 x 10
-8
Enforcement organisations
★
International Atomic Energy Agency
★
★
International Nuclear Safety Advisory Group
★
United States Atomic Energy Commission
★
★
Nuclear Regulatory Commission (U.S.A)
★
Canadian Nuclear Safety Commission
★
Autorité de sûreté nucléaire, the French nuclear safety authority
★
Radiological Protection Institute of Ireland
★
Federal Atomic Energy Agency in
Russia
★
Radiation and Nuclear Safety Authority of
Finland
★
Nuclear Installations Inspectorate (UK)
★ Defence Nuclear Safety Regulator (UK)
Lists of nuclear accidents
★
List of civilian nuclear accidents
★
List of civilian radiation accidents
★
List of military nuclear accidents
See also
★
Nuclear safety in the U.S.
★
Yucca Mountain
★
Deep geological repository
References
1. About NRC, U.S. Nuclear Regulatory Commission, Retrieved 2007-6-1
2. Our Governing Legislation, U.S. Nuclear Regulatory Commission, Retrieved 2007-6-1
3. [1]
4. Next-generation nuclear energy: The ESBWR