Impact of Partitioning and Transmutation on LWR High-Level Waste Disposal

Abstract

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.

Transmutation of Long-Lived Nuclear Wastes

“…Since the remaining elements do not contain large amount of heat generating nuclides nor long-lived α-emitting nuclides, they can be disposed of in a reasonable manner; for example, the area of the disposal site can be reduced by a factor of 100. [1] It should be, however, noted that the remaining elements still contain LLFPs such as 93 Zr and 126 Sn, and hence the deep geological disposal needs to isolate these LLFPs from biosphere. To avoid the deep geological disposal, further partitioning of LLFPs and their transmutation into short-lived or stable ones are required, which seems very tough challenge from viewpoints of energy consumption and cost.…”

Shortening transmutation time by using the molten salt reactor

“…Although the number of facilities for the P&T process has been mentioned in some studies, no particular attention has been paid to the duration (OECD, 2009). The reason for this might be that the benefit of P&T for final disposal has been of primary interest (Nishihara et al, 2008;González-Romero, 2011 The relation between the duration and the efficiency of the P&T process is analyzed in the present paper. In addition to burn-up and reprocessing losses, the refreshing time for the fuel and the deployed thermal power of the facility are considered.…”

Feasibility study of nuclear transmutation by negative muon capture reaction using the PHITS code

“…Partitioning and transmutation (P&T) have been investigated to reduce the radiotoxicity and storage time of the high-level radioactive waste (HLW) [1][2][3][4][5]. In the present reprocessing, U and Pu are recovered from spent fuel and HLW is vitrified.…”