Safety Design Concepts for ITER-Tritium Facility: - Toward construction in Japan -

In Japan, Fundamental approach for ensuring safety of the ITER plant was established by the Technical Advisory Committee for the Reactor Regulation Division of Science and Technology Agency of Japan in 2000. The approach settled the basic safety principles and approaches as the technical requirements on safety design and assessment derived from the safety characteristics of the ITER plant It was concluded that prevention of accidents can be achieved sufficiently by means of ensuring and maintaining the structural integrity of the enclosures containing radioactive materials against anticipated loads during operation, and low hazard potential of radioactive materials contained can be maintained within prescribed limits sufficiently by the vented detritiation/filtering clean-up system (confinement system) even if large release is postulated. For embodiment of the safety design concepts to the ITER tritium facility, some practical considerations should be taken for the tritium containment barriers, e.g., limitation of tritium permeation and leak, provision of an appropriate ventilation/detritiation system for maintenance, those to ensure the mechanical integrity etc.