![]() Ten years after use, the surface of a spent fuel assembly releases 10,000 rem/hr of radiation (in comparison, a dose of 500 rem is lethal to humans if received all at once).In 2011, 27% of spent fuel was held in dry casks, after sufficient cooling in storage pools. Dry casks, large concrete and stainless steel containers, are designed to passively cool radioactive waste and withstand natural disasters or large impacts. spent fuel pools are reaching capacity, necessitating the use of dry cask storage. The process reduces waste and extracts 25-30% more energy than non-reprocessed fuel. Many countries, though not the U.S., reprocess used nuclear fuel.Spent fuel is placed in a storage pool of circulating cooled water to absorb heat and block the high radioactivity of fission products.Spent fuel is 95% non-fissile U-238, 3% fission products, 1% fissile U-235, and 1% plutonium. During reactor operation, fission products and transuranics that absorb neutrons accumulate, requiring a third of the fuel to be replaced every 12-18 months.annually accumulates about 2,000 mt of spent fuel. For PWRs and BWRs most environmental impacts are caused by the extraction and production of fuel elements.Uranium is mostly extracted by open pit mining (16.1%), underground mining (20%) and in-situ leaching (ISL) (57.4%).Nuclear power plants consume 270-670 gallons of water/MWh, depending on operating efficiency and site conditions.The life cycle GHG intensity of nuclear power is estimated to be 34-60 gCO 2e/kWh-far below baseload sources such as coal (1,001 gCO 2e/kWh). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |