Investigation of Yucca Mountain repository capacity for the US spent nuclear fuel inventory

An analytical decay heat model was developed to evaluate the US inventory of commercial spent nuclear fuel (SNF). The model was benchmarked against the results from ORIGEN-ARP 5.01. The new analytical SNF decay heat model was applied to actual (thru 2002) and projected SNF data. The total decay heat from the 63,000 MT commercial SNF at year 2012 was estimated at 182 MW. According to the thermal loading analysis using a mountain-scale heat transfer model, a 4.9 km2 (1165 acre) site designated for SNF disposal was found to have the capacity to store more SNF than the statutory limit of 70,000 MTIHM. The maximum capacity available for SNF disposal at the Yucca Mountain site is dependent upon the thermal loading strategy chosen and SNF cooling time before emplacement. It was also shown that using high burnup SNF and adjusting the drift spacing, the capacity of the repository could be maximized on a per energy production basis, although some additional cooling may be necessary. Future work needs to consider extending the ‘footprint’ of the repository, applying non-uniform SNF loading into the drifts, and the impact of spent fuel reprocessing and other decay heat management strategies.