Selective Use of Thorium and Heterogeneity in Uranium-Efficient Pressurized Water Reactors

摘要

Systematic procedures have been developed and applied to assess the uranium utilization potential of a broad range of options involving the selective use of thorium in Pressurized Water Reactors (PWRs) operating on the once-through cycle. The methods used rely on state-of-the-art physics methods coupled with batch-wise core depletion models based on the group-and-one-half theory. The possible roles for thorium that were investigated are: as internal and radial blanket material, as thorium pins dispersed within uranium fuel assemblies, its use in PWRs operating on spectral shift control, and its reconstitution and reinsertion as radial blanket assemblies. The use of smaller assemblies in PWRs (for cores with and without thorium) was also investigated, as well as options which can be regarded as reasonable substitutes for employing thorium. The analyses were performed for both current (3-batch, discharge burnup approx. 30 GWD/MT) and high-burnup (5-batch, discharge burnup approx. 50 GWD/MT) PWR cores in their steady-state. (ERA citation 08:009840)