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The Nuclear Fuel Cycle. NUCLEAR FUEL. Nuclear fuel is the energy source of nuclear reactors and an essential element of the reactor core. The heat energy it supplies is produced by successive fissions of the nuclei of uranium 235
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NUCLEAR FUEL • Nuclear fuel is the energy source of nuclear reactors and an essential element of the reactor core. • The heat energy it supplies is produced by successive fissions of the nuclei of uranium 235 • The fuel pellets have been enriched to about 4 % instead of the 0.7 % existing in natural uranium.
U.S. Electricity Production • The main types of electricity generation in the U.S. are coal, natural gas, nuclear and Hydro. • Renewables include: Wood, Waste, Landfill Gas, Geothermal, Solar and Wind • Information from: http://www.eia.doe.gov/cneaf/electricity/epm/table1_1.html
US Commercial Reactors (103) produce approx. 20% of the electricity generated in the U.S. today.
Radioactive Waste • Two levels of radioactive waste exist: • Low Level Waste: • Medical applications • Industrial scanners • Research labs • Nuclear plant resins& hardware • High-Level Waste • Spent Nuclear Fuel • Defense Wastes
Low Level Radioactive Waste At a site in Hanford, Washington… • Placed in 150 ft wide, 45 ft deep, and 850 ft long trenches • Covered with at least 8 ft of soil • Marked with important information: contents, boundaries, date, etc. • Filled 17 trenches in 30 years
High Level Radioactive Waste • Yucca Mountain is a proposed site for long term storage • Licensing put on hold in 2010
WIPPWaste Isolation Pilot Plant near Carlsbad, N.M. Certified to store Defense related nuclear waste Located ½ mile underground in a salt mine Operational since 1999 for long term storage Not permitted to store waste from commercial reactors Storage of waste is a known technology There is no difference between defense waste and commercial waste
High Level Radioactive Waste • Dry Storage is currently used for long term storage of commercial waste • One cask typically holds 24 fuel assemblies • 2-3 casks per plant are needed for one year’s worth of electricity generation • The above picture shows the entire dry cask storage for about 30 years of generation at Connecticut Yankee (currently decommissioned)