A generation II reactor is a design classification for a

nuclear reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ...

, and refers to the class of commercial reactors built until the end of the 1990s. Prototypical and older versions of PWR,

CANDU The CANDU (Canada Deuterium Uranium) is a Canadian pressurized heavy-water reactor design used to generate electric power. The acronym refers to its deuterium oxide ( heavy water) moderator and its use of (originally, natural) uranium fuel. C ...

BWR A boiling water reactor (BWR) is a type of light water nuclear reactor used for the generation of electrical power. It is a design different from a Soviet graphite-moderated RBMK. It is the second most common type of electricity-generating nuc ...

, AGR, RBMK and

VVER The water-water energetic reactor (WWER), or VVER (from russian: водо-водяной энергетический реактор; transliterates as ; ''water-water power reactor'') is a series of pressurized water reactor designs originally de ...

are among them. These are contrasted to reactors, which refer to the early prototype of power reactors, such as Shippingport,

Magnox Magnox is a type of nuclear power/production reactor that was designed to run on natural uranium with graphite as the moderator and carbon dioxide gas as the heat exchange coolant. It belongs to the wider class of gas-cooled reactors. The n ...

/ UNGG,

AMB AMB may refer to: * Active magnetic bearing * Advanced Memory Buffer, used in Fully Buffered DIMM memory * Al-Aqsa Martyrs Brigades, one of the armed sections of the Palestinian Fatah movement * Ambergate railway station, abbreviation used in th ...

, Fermi 1, and Dresden 1. The last commercial Gen I power reactor was located at the

Wylfa Nuclear Power Station Wylfa nuclear power station ( cy, Atomfa'r Wylfa) is a Magnox nuclear power station undergoing decommissioning. Wylfa is situated west of Cemaes Bay on the island of Anglesey, off the northwestern coast of Wales. Construction of the two 490MW ...

and ceased operation at the end of 2015. The

nomenclature Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal conventions of everyday speech to the internationally ag ...

for reactor designs, describing four 'generations', was proposed by the US Department of Energy when it introduced the concept of

generation IV reactor Generation IV reactors (Gen IV) are six nuclear reactor designs recognized by the Generation IV International Forum. The designs target improved safety, sustainability, efficiency, and cost. The most developed Gen IV reactor design is the sodium ...

s. The designation ''generation II+ reactor'' is sometimes used for modernized generation II designs built post-2000, such as the Chinese CPR-1000, in competition with more expensive

generation III reactor Generation III reactors, or Gen III reactors, are a class of nuclear reactors designed to succeed Generation II reactors, incorporating evolutionary improvements in design. These include improved fuel technology, higher thermal efficiency, sign ...

designs. Typically, the modernization includes improved safety systems and a 60-year design life. Generation II reactor designs generally had an original design life of 30 or 40 years. This date was set as the period over which loans taken out for the plant would be paid off. However, many generation II reactors are being life-extended to 50 or 60 years, and a second life-extension to 80 years may also be economic in many cases. By 2013 about 75% of still operating U.S. reactors had been granted life extension licenses to 60 years.

Chernobyl Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about n ...

's No.4 reactor that exploded was a generation II reactor, specifically RBMK-1000. Fukushima Daiichi's three destroyed reactors were generation II reactors; specifically Mark I Boiling water reactors (BWR) designed by

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable ene ...

. In 2016, unit 2 at the Watts Bar Nuclear Generating Station came online and is likely to be the last generation II reactor to become operational in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

References

External links

Nuclear Reactors Knowledge Base at IAEA

Nuclear power reactor types {{nuclear-energy-stub

See also

References

External links