Impact of partitioning and transmutation on LWR high-level waste disposal

Partitioning and/or transmutation (PT) technology affects the disposal concept of high-level radioactive waste (HLW). We studied how cooling in the predisposal storage period may affect the design of the emplacement area in a repository for radioactive wastes produced by a light-water-reactor nuclear system that uses PT technology. Three different fuel cycle scenarios involving PT technology were analyzed: 1) partitioning process only (separation of some fission products), 2) transmutation process only (separation and transmutation of minor actinides), and 3) both partitioning and transmutation. The necessary predisposal storage periods for some predefined emplacement configurations were determined through transient thermal analysis, and the relation between the storage period and the emplacement area was obtained. For each scenario, we also estimated the storage capacity required for the dry storage of the heat-generating waste forms. The contributions of PT technology on the storage and disposal were discussed holistically, and we noted that the coupled introduction of partitioning and transmutation processes can bring an appreciable reduction in waste management size. (author)