Technology development for nuclear fuel cycles

The technology for nuclear fuel cycles has been playing more and more important roles in the field of nuclear energy development. Hitachi, Ltd. has participated in technological development and construction of facilities in the fields such as uranium enrichment, fuel fabrication/reprocessing, radioactive waste processing/disposal, etc. Aiming to establish a total solution system for complete nuclear fuel cycle, a high-performance cement solidification method was developed to effectively immobilize radioactive wastes from a nuclear power plant. Furthermore, development of continuous melting techniques is under way to substantially improve the volume reducing capacity for miscellaneous solid wastes. As smooth operation of nuclear power plants, nuclear waste fuels are increasing, now. Since it is thus required to increase their storage capacities, a new type 'boron rack' which allows to improve the storage density by raising the capacity of neutron absorption was developed and its practical application was succeeded. In addition, development of practical dry-storage technology for spent fuels including metallic cask and vault storage systems are progressing now. (M.N.)