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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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ANS joins others in seeking to discuss SNF/HLW impasse
The American Nuclear Society joined seven other organizations to send a letter to Energy Secretary Christopher Wright on July 8, asking to meet with him to discuss “the restoration of a highly functioning program to meet DOE’s legal responsibility to manage and dispose of the nation’s commercial and legacy defense spent nuclear fuel (SNF) and high-level radioactive waste (HLW).”
Thomas A. Buscheck, John J. Nitao
Nuclear Technology | Volume 104 | Number 3 | December 1993 | Pages 418-448
Technical Paper | Special Issue on Waste Management / Radioactive Waste Management | doi.org/10.13182/NT93-A34901
Articles are hosted by Taylor and Francis Online.
To safely and permanently store high-level nuclear waste, the potential Yucca Mountain repository site must mitigate the release and transport of radionuclides for tens of thousands of years. In the failure scenario of greatest concern, water would contact a waste package, accelerate its failure rate, and eventually transport radionuclides to the water table. Analyses have demonstrated that (a) the ambient hydrological system will be dominated by repository-heat-driven hydrothermal flow for tens of thousands of years and (b) the only significant source of liquid water is from nonequilibrium fracture flow, driven either by meteoric sources or by the condensation of repository-heat-driven flow of water vapor. For sub-boiling conditions, the infiltration of meteoric water and condensate drainage are controlled by the highly heterogeneous distribution of hydrological properties, while for above-boiling conditions, they are largely determined thermodynamically. In a concept called the “extended-dry repository,” the heat of radioactive decay generates a region of above-boiling temperatures around the repository, thereby extending the time before liquid water can contact a waste package. It is also found that the magnitude of repository-heat-driven, buoyant, liquid-phase convection in the saturated zone is more dependent on the total mass of emplaced spent nuclear fuel (SNF) than on the details of SNF emplacement, such as the areal power density (expressed in kilowatts per acre) or SNF age.