Core damage frequency

Core damage frequency

Core damage frequency (CDF) is a term used in probabilistic risk assessment (PRA) that indicates the likelihood of an accident that would cause damage to a nuclear reactor core.[1][2][3] Core damage accidents are considered serious because damage to the core may prevent control of the nuclear reaction, which can lead to a nuclear meltdown.[3] Some sources on CDF consider core damage and core meltdown to be the same thing, and different methods of measurement are used between industries and nations, so the primary value of the CDF number is in managing the risk of core accidents within a system and not necessarily to provide large-scale statistics.[3][4]

An assessment of permanent or temporary changes in a nuclear power plant is performed to evaluate if such changes are within risk criteria. For example, the probability of core damage may increase while replacing a component, but the probability would be even higher if that component were to fail because it wasn't replaced.[4] Risk measures, such as core damage frequency and large early release frequency (LERF), determine the risk criteria for such changes.

This risk analysis allows decision making of any changes within a nuclear power plant in accordance with legislation, safety margins and performance strategies.

A 2003 study commissioned by the European Commission remarked that "core damage frequencies of 5 × 10−5 [per reactor-year] are a common result" or in other words, one core damage incident in 20,000 reactor years.[3] A 2008 study performed by the Electric Power Research Institute, the estimated core damage frequency for the United States nuclear industry is estimated at once in 50,000 reactor years, or 2 × 10−5.[5]

Assuming there are 500 reactors in use in the world, the above numbers mean that, statistically, one core damage incident would be expected to occur somewhere in the world every 40 or 100 years, respectively.

Historically first nuclear power was achieved about 60 year ago. The 582 operational reactors that were built since account for about 14,400 reactor years. The numbers above would imply that this should have accounted for less than one accident. However, of these 582 reactors 11 reactors have suffered from serious core damage[6], resulting in a historical accident rate of 1 in every 1,309 reactor years, about 15 times more frequently than the EU estimate (1/20,000 reactor yrs) and about 35 more frequently compared to the US estimate (1/50,000 reactor yrs).

During the 2011 earthquake and resultant 15+ meter tsunami on the east coast of Japan, the Fukushima I nuclear power plant suffered core damages at three of its six reactors after the emergency core cooling systems failed due to the extreme beyond design basis conditions. The reactors were General Electric BWR-3 and BWR-4 types inside Mark I containments. These had been estimated to have a core damage frequency between 10−4 and 10−7[7]

See also


External links

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • core damage frequency — branduolinio reaktoriaus šerdies pažeidimo dažnis statusas Aprobuotas sritis branduolinė sauga apibrėžtis Įvykių sekų, kurios gali lemti branduolinio reaktoriaus šerdies pažeidimą, suminis dažnis. atitikmenys: angl. core damage frequency šaltinis …   Lithuanian dictionary (lietuvių žodynas)

  • 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, and the use and storage of… …   Wikipedia

  • Nuclear safety in the United States — Nuclear safety in the U.S. is governed by federal regulations and continues to be studied by the Nuclear Regulatory Commission (NRC). The safety of nuclear plants and materials controlled by the U.S. government for research and weapons production …   Wikipedia

  • International Nuclear Event Scale — The International Nuclear and Radiological Event Scale (INES) was introduced in 1990[1] by the International Atomic Energy Agency (IAEA) in order to enable prompt communication of safety significance information in case of nuclear accidents. The… …   Wikipedia

  • List of mathematics articles (C) — NOTOC C C closed subgroup C minimal theory C normal subgroup C number C semiring C space C symmetry C* algebra C0 semigroup CA group Cabal (set theory) Cabibbo Kobayashi Maskawa matrix Cabinet projection Cable knot Cabri Geometry Cabtaxi number… …   Wikipedia

  • Areva EPR — Fotomontage des im Bau befindlichen EPR (links im Bild) im Kernkraftwerk Olkiluoto Der EPR ist der größte Kernkraftwerkstyp des französischen Nuklearkonzerns Areva. Früher als European Pressurized Water Reactor vermarktet, ist die Abkürzung EPR… …   Deutsch Wikipedia

  • Economic Simplified Boiling Water Reactor — The reactor formally known as Economic Simplified Boiling Water Reactor (ESBWR) is a passively safe generation III+ reactor which builds on the success of the ABWR. Both are designs by General Electric, and are based on their BWR design.The ESBWR …   Wikipedia

  • Nuclear power in the United States — For a comprehensive list of U.S. plants, see List of nuclear reactors. NRC regions and locations of nuclear reactors, 2008 Main article: Nuclear power As of 2008, nuclear power in the United States is provided by 104 commercial reactors (69 …   Wikipedia

  • International Reactor Innovative and Secure — (IRIS) is a Generation IV reactor reactor design made by an international team of companies, laboratories, and universities and coordinated by Westinghouse. IRIS is hoped to open up new markets for nuclear power and make a bridge from Generation… …   Wikipedia

  • AP1000 — Westinghouse Electric Company s AP1000 reactor design is the first Generation III+ reactor to receive final design approval from the NRC.cite web | title =AP 1000 Public Safety and Licensing | work = | publisher =Westinghouse | date =2004 09 13 | …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”