Effect of rod consolidation on spent fuel disposal costs

The US Dept. of Energy (DOE) plans for the management of spent power reactor fuel are based on the assumption that individual fuel rods may be removed from the fuel assemblies and consolidated in close-packed arrays, thus reducing the number of waste containers to be disposed of. The reasoning is that it may cost less to develop, build, and operate the facilities and equipment required for consolidation than it would to buy, load, and emplace the extra containers required for the disposal of intact fuel assemblies. In its role supporting the DOE's Nevada Nuclear Waste Storage Investigations (NNWSI) project, Sandia National Laboratories has assessed the cost effectiveness of consolidation at a repository being considered for location in the tuff deposits at Yucca Mountain in Nye County, Nevada. For this study, it was assumed that all spent fuel is shipped to the repository as intact fuel assemblies. Costs were compared for two basic disposal options, one based on at-repository consolidation, the other based on disposal of intact fuel assemblies. For both options, mining, drilling, and emplacement costs were estimated for two emplacement configurations - single containers in vertical boreholes, and multiple containers in long, horizontal boreholes.