COMPREHENSIVE SAFETY ANALYSIS CODE SYSTEM FOR NUCLEAR-FUSION REACTORS.2. THERMAL ANALYSES DURING PLASMA DISRUPTIONS FOR INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR

Thermal characteristics of a fusion reactor [International Thermonucle ar Experimental Reactor (ITER) Conceptual Design Activity] during plas ma disruptions have been analyzed by using a comprehensive safety anal ysis code for nuclear fusion reactors. The erosion depth due to disrup tions for the armor of the first wall depends on the current quench ti me of disruptions occurring in normal operation. If it is possible to extend the time up to approximately 50 ms, the erosion depth is consid erably reduced. On the other hand, the erosion depth of the divertor i s approximately 570 mum for only one disruption, which is determined o nly by the thermal flux during the thermal quench. This means that the divertor plate should be exchanged after about nine disruptions. Coun termeasures are necessary for the divertor to relieve disruption influ ences. As other scenarios of disruptions, beta-limit disruptions and v ertical displacement events were also investigated quantitatively.