- High level waste
High level waste (HLW) is a type of
nuclear wastethat arises from the use of uranium fuel in a nuclear reactorand nuclear weapons processing. It contains the fission productsand transuranicelements generated in the reactor core. HLW accounts for over 95% of the total radioactivity produced in the process of nuclear electricity generation.
High level waste is very radioactive and, therefore, requires special shielding during handling and transport. It also needs cooling, because it generates a great deal of heat.
It is generally accepted that the final waste will be disposed of in a
deep geological repository, and many countries have developed plans for such a site, including France, Japan, and the United States.
High level waste is defined as:
"Spent (used) reactor fuel".
Spent nuclear fuelis used fuel from a reactor that is no longer efficient in creating electricity, because its fission process has slowed due to a build-up of reaction poisons. However, it is still thermally hot, highly radioactive, and potentially harmful.
"Waste materials from reprocessing".
nuclear weapons are acquired by reprocessing spent nuclear fuel from breeder reactors. Reprocessing is a method of chemically treating spent fuel to separate out uranium and plutonium. The byproduct of reprocessing is a highly radioactive sludgeresidue.
Disposing of high-level wastes
High-level radioactive waste is stored temporarily in
spent fuel pools and in dry cask storagefacilities.
In 1997, in the 20 countries which account for most of the world's nuclear power generation, spent fuel storage capacity at the reactors was 148,000 tonnes, with 59% of this utilized. Away-from-reactor storage capacity was 78,000 tonnes, with 44% utilised. With annual additions of about 12,000 tonnes, issues for final disposal are not urgent.
* [http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/radwaste.html NRC Backgrounder on Radioactive Waste]
low level waste
spent nuclear fuel
Fentiman, Audeen W. and James H. Saling. "Radioactive Waste Management". New York: Taylor & Francis, 2002. Second ed.
Large, John H. "Risks and Hazards arising the Transportation of Irradiated Fuel and Nuclear Materials in the United Kingdom" R3144-A1, March 2006 [http://www.largeassociates.com/3144%20Spent%20Fuel/R3144-A2%20FINAL.pdf]
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Look at other dictionaries:
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