科学挑战处置库中的废物.ppt

* * * * Heat Production The handling of the nuclear wastes is significantly complicated by the heat generated in the decay of the radionuclides The heat generation per unit activity depends on the energy carried by the emitted particles. 1 megacurie → 5.93 kW (at 1 MeV per disintegration). Decay of spent fuel from 1 GWyr of PWR operation, for burnup of 40 GWd/t (28.5 MTHM): activity and thermal output as a function of time since discharge. 1.3 Hazard Measures for Nuclear Wastes Total System Performance Assessments (TSPAs) The maximum permissible concentration is established as the maximum level acceptable for drinking water is closely related to the annual limit on intake (ALI). 20 mSv/yr The water dilution volume (in cubic meters) is the amount of water required to dilute the radionuclide to the maximum permissible concentration. Illustration of use of water dilution volume: WDV of radionuclides in PWR spent fuel, as a function of time Chapter 7. Nuclear Waste Nuclear Waste Disposal: Amounts of Waste Categories of Nuclear Waste Wastes from Commercial Reactors Hazard Measures for Nuclear Wastes 2. Storage and Disposal of Nuclear Wastes Stages in Waste Handling Deep Geologic Disposal Alternatives to Deep Geologic Disposal Worldwide Status of Nuclear Waste Disposal Plans Waste Storage Alternatives Leave It Where It Is Deep Geologic Disposal Yucca Mountain, Nevada Salt Cave Disposal WIPP near Carlsbad, New Mexico Very Deep Holes (6 miles) Ice-Sheet Disposal Space Disposal Sub-Seabed Disposal Island Geologic Disposal Deep-Well Injection Disposal Vitrification (Glass Waste) Reprocessing It is better to have used nuclear fuel in one location NIMBY: Not In My Back Yard Fear of radiation because they don’t understand it Concern that the waste facility willrelease long-term contamination Worry that property values will be reducedwith construction of a waste facility Belief that power companies are the ones responsible for storing their own waste People don’