54°38N 3°30W. Nuclear power plant in Cumbria, NW England; on the Irish Sea coast, W of Gosforth; processes nuclear waste; process of decomissioning begun, 2005; nearby Calder Hall gas-cooled, moderated nuclear reactors, operational 19562003.
Sellafield is the name of a nuclear site, close to the village and railway station of Seascale, operated by the British Nuclear Group, but owned since 1 April 2005 by the Nuclear Decommissioning Authority. It houses the Thorp nuclear fuel reprocessing plant, the Magnox nuclear fuel reprocessing plant, the inactive Calder Hall Magnox nuclear power station — the world's first commercial nuclear power station, and other older nuclear facilities.
History
The Sellafield site is built on land that was formerly part of the Windscale nuclear site, which is named after a nearby village. Two air-cooled, graphite-moderated Windscale reactors constituted the first British weapons grade plutonium 239 production facility, built for the British nuclear weapons program in the late 40s and the 50s.
Windscale was also the site of the prototype British Advanced gas-cooled reactor.
Since its inception Sellafield has also been host to a number of reprocessing facilities, which separate the uranium, plutonium and other fission products from spent nuclear fuel. The uranium can then be used in the manufacture of new nuclear fuel, or in applications where its density is an asset. The plutonium can be used in the manufacture of mixed oxide (MOX) fuel for thermal reactors, or as fuel for fast breeder reactors, such as the Prototype Fast Reactor at Dounreay.
Major plants
The Windscale Piles
Following the decision taken in January 1947 for the UK to have an independent nuclear deterent, Sellafield was chosen as the location of the plutonium production plant , with the initial fuel load into the Windscale Piles commencing July 1950. By July of 1952 the separation plant was being used to separate plutonium and uranium from spent fuel.
Unlike the early US reactors at Hanford, which consisted of a graphite core cooled by water, the Windscale Piles consisted of a graphite core cooled by air. Fuel for the reactor consisted of rods of uranium metal, approximately 1 foot long by one inch in diameter, and clad in Aluminium
The Windscale fire
The piles were shut down following a fire in Pile 1 on 10 October, 1957 which destroyed the core and released an estimated 750 terabecquerels (TBq) (20,000 curies) of radioactive material into the surrounding environment, including Iodine-131, which is taken up in the body by the thyroid.
In the 1990s, the UKAEA started to implement plans to decommission, disassemble and clean up, both piles;
The first generation reprocessing plant
This reprocessing plant was built to extract the plutonium from spent fuel as part of the effort to build the UK's atomic weapons. Following the commissioning of the Magnox reprocessing plant, it was itself recycled to become a pre-handling plant to allow oxide fuel to be reprocessed in the new plant, and was closed in 1973.
Calder Hall nuclear power station
Calder Hall was the world's first commercial nuclear power station.
Calder Hall had 4 Magnox reactors capable of generating 50 MWe of power each.
However, in its early life, it was primarily used to produce weapons-grade plutonium, with two fuel loads per year, and electricity production as a secondary purpose.
Windscale Advanced Gas Cooled Reactor (WAGR)
The Windscale Advanced Gas Cooled Reactor (WAGR) was a prototype for the UK's second generation of reactors, the Advanced gas-cooled reactor or AGR, which followed on from the Magnox stations. This reactor was shut down in 1981, and is now part of a pilot project to demonstrate techniques for safely decommissioning a nuclear reactor.
Magnox reprocessing plant
In 1964 the Magnox reprocessing plant came on stream to reprocess spent nuclear fuel from the Magnox reactors. The plant uses the "plutonium uranium extraction" Purex method for reprocessing spent fuel, with tributyl phosphate as an extraction agent.
HALES
Highly Active Liquor Evaporation and Storage (HALES) is a department at Sellafield. It conditions nuclear waste streams prior to transfer to the Thermal Oxide Reprocessing Plant plant.
Thermal Oxide Reprocessing Plant
Between 1977 and 1978 an inquiry was held into an application by BNFL for outline planning permission to build a new plant to reprocess irradiated oxide nuclear fuel from both UK and foreign reactors. If yes, should the reprocessing plant be about double the estimated site required to handle United Kingdom oxide fuels and be used as to the spare capacity, for reprocessing foreign fuels?". The result of the inquiry was that the new plant, the Thermal Oxide Reprocessing Plant (Thorp) was given the go ahead in 1978, although it did not go into operation until 1994.
2005 Thorp plant leak
Wikinews has news related to: Nuclear waste leaks at Sellafield facility on Cumbrian coast, EnglandOn April 19, 2005 83,000 litres of radioactive waste was discovered to have leaked in the Thorp reprocessing plant from a cracked pipe into a huge stainless steel-lined concrete sump chamber built to contain leaks.
A discrepancy between the amount of material entering and exiting the Thorp processing system had first been noted in August 2004.
Other indicators of a problem included a rise in temperature in the sump chamber and findings of radioactive fluid there, but these were ignored.
Responsible administrators have been disciplined.
The Vitrification Plant
In 1991 the Windscale Vitrification Plant, which converts high-level radioctive waste into glass, was opened.
The plant has three process lines and is based on the French AVM procedure.
The Sellafield MOX Plant
Construction of the Sellafield MOX Plant was completed in 1997. Mixed oxide, or MOX fuel, is a blend of plutonium and natural uranium or depleted uranium which behaves similarly (though not identically) to the enriched uranium feed for which most nuclear reactors were designed. MOX fuel is an alternative to Low enriched uranium (LEU) fuel used in the light water reactors which predominate in nuclear power generation.
Sellafield and the local community
Sellafield directly employs around 10,000 people and is one of the two largest, non-governmental, employers in West Cumbria (along with BAE Systems at Barrow-in-Furness), with approximately 90% of the employees coming from West Cumbria.
Sellafield Visitors' Centre
Close to the Sellafield site is the Sellafield Visitors' Centre, which has a number of interactive exhibits, science workshops, and Europe's first immersion cinema.
Controversy
The site has been the subject of much controversy because of discharges of radioactive material, mainly accidental but some alleged to have been deliberate.
Between 1950 and 2000 there have been 21 serious incidents or accidents involving some off-site radiological releases that merited a rating on the International Nuclear Event Scale, one at level 5, 5 at level 4 and 15 at level 3.
In the hasty effort to build the 'British Bomb' in the 1940s and 1950s, radioactive waste was diluted and discharged by pipeline into the Irish Sea. Most of the area's long-lived radioactive technetium comes from the reprocessing of spent nuclear fuel at the Sellafield facility .
Technetium-99 is a radioactive element which is produced by nuclear fuel reprocessing, and also as a byproduct of medical facilities (for example Ireland discharges approximately 6.78GBq of Technetium-99 each year despite not having a nuclear industry ). Because it is almost uniquely produced by nuclear fuel reprocessing, Technetium-99 is an important element as part of the Oslo Convention for the North-East Atlantic (OSPAR) since it provides a good tracer for discharges into the sea.
In itself, the technetium discharges do not represent a significant radiological hazard, and recent studies have noted "...that in the most recently reported dose estimates for the most exposed Sellafield group of seafood consumers (FSA/SEPA 2000), the contributions from 99Tc and actinide nuclides from Sellafield (<100 µSv) was less than that from 210Po attributable to discharges from the Whitehaven phosphate processing plant and probably less than the dose from naturally occurring background levels of 210Po." Because of the need to comply with OSPAR, British Nuclear Group (the licencing company for Sellafield) have recently commissioned a new process in which Technetium-99 is removed from the waste stream and vitrified in glass blocks.
There has been concern that the Sellafield area will become a major dumping ground for unwanted nuclear material, since there are currently no long-term facilities for storing High-Level Waste (HLW), although the UK has current contracts to reprocess spent fuel from all over the world.
MOX fuel quality data falsification
The MOX Demonstration Facility was a small-scale plant to produce commercial quality MOX fuel for light water reactorss.
In 1999 it was discovered that the plant's staff had been falsifying some quality assurance data since 1996.
BNFL had to pay compensation to the Japanese customer, Kansai Electric, and take back a flawed shipment of MOX fuel from Japan.
The "Beach Incident"
1983 was the year of the "Beach Discharge Incident" in which high radioactive discharges resulted in the closure of a beach. 1983 was also the year in which Yorkshire Television produced a documentary "Windscale: The Nuclear Laundry", which claimed that the low levels of radioactivity that are associated with waste streams from nuclear plants such as Sellafield did pose a non-negligible risk.
In its early days, Sellafield discharged low-level radioactive waste into the sea, using a flocculation process to remove radioactivity from liquid effluent before discharged.
Leukemia risks
In the early 1990s, concern was raised in the UK about apparent clusters of leukemia near nuclear facilities. Detailed studies carried out by the Committee on Medical Aspects of Radiation in the Environment (COMARE) in 2003 found no evidence of raised childhood cancer around nuclear power plants, but did find an excess of leukaemia and non-Hodgkin's lymphoma (NHL) near other nuclear installations including Sellafield, AWE Burghfield and UKAEA Dounreay.
Irish objections
Sellafield has been a matter of some consternation in Ireland, with the Irish Government and some members of the population concerned at the risk that such a facility may pose to the country.
Norwegian objections
Similar sentiments are shared by the Norwegian government and population, because the prevailing sea currents transport radioactive materials leaked into the sea along the entire coast of Norway.
Plutonium records discrepancy
On February 17, 2005, the UK Atomic Energy Authority reported that 29.6 kg (65.3 lb) of plutonium, enough to make seven nuclear bombs, was unaccounted for in auditing records at the Sellafield nuclear fuel reprocessing plant.
Sellafield in music and television
German band Kraftwerk opened the song Radioactivity on their June 2005 live album Minimum-Maximum with an audio clip criticizing the Sellafield-2 reactor for radiation released into the atmosphere during typical operation and the dangers of reprocessing plutonium in regard to nuclear proliferation. Sellafield-2 was the name given by environmental groups including Greenpeace to a proposed second plant to reprocess oxide fuel (it is not obvious how seriously proposed, a public enquiry was never opened).
Fallout, a programme shown on the Irish national TV station RTÉ was a documentary-style drama showing the possible effects of a serious accident at Sellafield.
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