Sellafield plant

A major reassessment of historical discharges and doses has been carried out, prompted in large part by civil litigation instigated by a number of local families against British Nuclear Fuels pic, the operators of the Sellafield plant. The reassessment involved the development of the Sellafield Environmental Assessment Model (SEAM), which was used both to calculate doses and to build confidence in the discharge chronology from recorded measurements of environmental concentrations and current assessments of environmental inventories. 

Major source terms from the Sellafield plant (Reprocessing activity, 1991)... 

Carlinford, Ireland (port city), impact from Sellafield Reprocessing Plant, 1991-1997 Ryanetal. 1999... 

Environmental Fate. The environmental fate of americium has been extensively studied in relation to its introduction into the Irish Sea from the BNFL nuclear fuel reprocessing plant at Sellafield, United Kingdom (Belot et al. 1982 Bennett 1976 Bunzl et al. 1994, 1995 Malcolm et al. 1990 McCartney et al. 1994 McKay et al. 1994a Murray et al. 1978, 1979 Pattenden and McKay 1994 Walker et al. 1986). 

In 1942, the Mallinckrodt Chemical Company adapted a diethylether extraction process to purify tons of uranium for the U.S. Manhattan Project [2] later, after an explosion, the process was switched to less volatile extractants. For simultaneous large-scale recovery of the plutonium in the spent fuel elements from the production reactors at Hanford, United States, methyl isobutyl ketone (MIBK) was originally chosen as extractant/solvent in the so-called Redox solvent extraction process. In the British Windscale plant, now Sellafield, another extractant/solvent, dibutylcarbitol (DBC or Butex), was preferred for reprocessing spent nuclear reactor fuels. These early extractants have now been replaced by tributylphosphate [TBP], diluted in an aliphatic hydrocarbon or mixture of such hydrocarbons, following the discovery of Warf [9] in 1945 that TBP separates tetravalent cerium from... 

Johnes, S. R., Fulkner, M. J., McKeever, J. Stewert, T. H. 1991. Aspects on population exposure consequent on discharges of radionuclides to the environment from the nuclear reprocessing plant at Sellafield at Cumbria. Radiation Protection Dosimetry, 36, 199-204. 

Gardner MJ, Snee MP, Hall AJ, Powell CA, Downes S, Terrell JD (1990) Results of case-control study of leukemia and lymphoma among young people near Sellafield nuclear plant in West Cumbria. Br Med J, 300(6722) 423-429. 

Although this has been shown to occur in experimental animals after exposure of males to foreign compounds such as cyclophosphamide, there is only inconclusive evidence that this occurs in humans. Thus, studies of exposure of human males to vinyl chloride, dibromo-chloropropane, and anesthetic gases, for example, have revealed only equivocal evidence of developmental toxicity in the offspring. There now seems to be some evidence that the leukemia occurring in children, which appears to be clustered around nuclear fuel-reprocessing plants such as Sellafield in the United Kingdom, may be due to paternal exposure to radiation. 

Phillips, C. 1999. The thermal oxide reprocessing plant at Sellafield Four years of active operation of the solvent extraction plant. ISEC 99 Conference on Solvent Extraction for the 21st Century, July, Barcelona, Spain. 

A cluster of cases of childhood leukemia has been found in West Cumbria (Forman et al., 1987). As a result, an exhaustive reexamination has been made of the emissions from the Windscale piles and the adjacent Sellafield reprocessing plant, including those before,... 

AVH [Atelier de Vitrification de la Hague] A process for immobilizing nuclear waste, operated at La Hague, France, based on the earlier AVM process. Used also in the THORP nuclear reprocessing plant at Sellafield, UK. 

Purex [Plutonium and uranium recovery by extraction] A process for the solvent extraction of plutonium from solutions of uranium and fission products, obtained by dissolving spent nuclear fuel elements in nitric acid. The solvent is tri- -butyl phosphate (TBP) in kerosene. First operated by the U.S. Atomic Energy Commission at its Savannah River plant, SC, in 1954 and at Hanford, WA, in 1956. Now in operation, with modifications, in several countries. Sites include Savannah River (SC), Cap de la Hague (France), Marcoule (France), Sellafield (England), Karlsruhe (Germany), and Trombay (India). See also Recuplex. 

The seas are a source of aerosol (i.e. small particles), which transfer to the atmosphere. These will subsequently deposit, possibly after chemical modification, either back in the sea (the major part) or on land (the minor part). Marine aerosol comprises largely unfractionated seawater, but may also contain some abnormally enriched components. One example of abnormal enrichment occurs on the eastern coast of the Irish Sea. Liquid effluents from the Sellafield nuclear fuel reprocessing plant in west Cumbria are discharged into the Irish Sea by pipeline. At one time, permitted discharges were appreciable and as a result radioisotopes such as Cs and several isotopes of plutonium have accumulated in the waters and sediments of the Irish Sea. A small fraction of these radioisotopes were carried back inland in marine aerosol and deposited predominantly in the coastal zone. While the abundance of Cs in marine aerosol was refiective only of its abundance in seawater (an enrichment factor - see Chapter 4 - of close to unity), plutonium was abnormally enriched due to selective incorporation of small suspended sediment particles in the aerosol. This has manifested itself in enrichment of plutonium in soils on the west Cumbrian coast,shown as contours of 239+240p deposition (pCi cm ) to soil in Figure 3. 

Irradiated Magnox and AGR fuel is stored at the power stations in open topped skips and transported to Sellafield in shielded flasks. At Sellafield, in the Fuel Handling Plant (FHP), the fuel is placed into ullaged containers which can be stacked. Based upon an extensive research programme an optimiun water chemistry of pH 13 was identified for the containers. Under these conditions storage times of at least five years without cladding penetration are achievable. 

Radioisotope Scavenging. Clinoptilolite has a relatively high Si/Al ratio and has the ability to scavenge cesium radioisotopes from aqueous nuclear wastes. An example of its industrial-scale use is in the development of the site ion-exchange effluent plant (SIXEP) by British Nuclear Fuels at their Sellafield site. This uses a clinoptilohte, from Mud Hills, California, and meets the stringent performance requirements. The Cs selectivity of clinoptilolite has led to its possible use to reduce Cs radioisotope body burdens in sheep, and mordenite has been studied for the same use in reindeer. Mordenite also has been used to treat aqueous nuclear waste, as has an acid washed chabazite (AW500). 

Jones, S.R., Williams, S.M., Smith, A.D. and Gray, J., Review of discharge history and population doses from the Sellafield reprocessing plant in Cumbria, UK The Sellafield environmental assessment model (SEAM), Reported at International Symposium on Environmental Impact of Radioactive Releases, Vienna, 8-12.05.1995, IAEA-SM-339/II. 

In order to be able to estimate the releases resulting from undeclared activities one should consider releases from the declared sites. As an example we consider here Sellafield reprocessing plant in the UK. 

British Nuclear Fuels Sellafield reprocessing plant publishes annual figures of measured discharges and local environmental measurements, in order to conform with environmental legislation (British Nuclear Fuels, 1992). The local environmental burden of anthropogenic radionuclides will be due to discharges from nuclear activities... 

There now seems to be some evidence that the leukaemia occurring in children, which appears to be clustered around nuclear fuel reprocessing plants such as Sellafield in the United Kingdom, may be due to paternal exposure to radiation. 

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