Design of High Performance Spent Fuel Shipping Cask

The construction plan for the Rokkasho reprocessing plant has been realized , and the preparation for the transportation of spent fuel to the plant is also being carried out aiming at the commencement of the plant operation. On the other hand, a high burn-up plan for long cycle operation of power plants has been greatly progressed. The majority of the spent fuels transported to the Rokkasho plant are expected to be the high burn-up fuel. To reduce the transport frequency by improving transport efficiency, the High Performance Spent Fuel Shipping Cask (HP-Cask) has been developed for optimum use of the caskhandling capacities of all power plants in Japan. High burn-up of fuel will accompany higher enrichment, greater radiation intensity and greater decay heat , and therefore radiation shielding will necessarily become thicker and external fins higher than the existing casks, and the contents (number of fuel assemblies) tend to be fewer.