Publications Details
Equivalent Energy Density concept: A preliminary reexamination of a technique for equating thermal loads; Yucca Mountain Site Characterization Project
Historical and projected inventories of spent fuel from commercial light-water nuclear reactors exhibit diverse decay characteristics and ages. This report summarizes a preliminary reexamination of a method for determining equivalent thermal loads for the range of spent fuel expected at a potential underground repository. The method, known at the Equivalent Energy Density (EED) concept, bases its equivalence criteria on the assumption that a given waste will produce worst-case thermomechanical effects equal to worst-case thermomechanical effects produced by a baseline waste, provided that the thermal energy deposited in the host rock over a specified deposition period is the same for both waste descriptions. To test this assumption, temperature histories at representative locations within the host rock were calculated using layouts defined by the EED concept and four deposition periods (20, 50, 100, and 300 years). It was found that the peak temperatures at near-field locations were best matched by the shorter deposition periods of 20 and 50 years. However, due to the sensitivity of the near-field environment to short-term canister-to-canister interactions, caution,should be used when choosing a near-field deposition period. At the location chosen to represent the far-field, a 300-year deposition period provided reasonable correspondence of peak temperature responses for all waste descriptions examined.