A Perspective on an R&D Program for Spent Fuel Interim Storage Cask System

Cask systems for spent fuel interim storage should have sufficient capability to comply with both transport and storage requirements. In recent years, spent nuclear fuels (SNFs) discharged from commercial nuclear power plants have a higher burnup rate and are stored after a shorter cooling time in the pools. On the market side, the economy of interim storage is regarded as just as important as keeping its safety. Mitsubishi Heavy Industries, Ltd. (MHI) has been developing a new “MSF” cask fleet for transport and storage of the SNFs, focusing on a large payload of high-burnup and short-cooled SNFs. For the development of the MSF casks, the research and development (R&D) program has targeted on improving their safety and reducing their manufacturing cost. This paper presents the approach and the results of the R&D program for the MSF cask fleet.