COMPREHENSIVE SAFETY ANALYSIS CODE SYSTEM FOR NUCLEAR-FUSION REACTORS.4. PRELIMINARY ESTIMATION OF DUST PRODUCTION DUE TO PLASMA DISRUPTIONS

Dust production due to plasma disruptions has been investigated using a safety analysis code, which can calculate the plasma dynamics and th ermal characteristics effusion reactor structures simultaneously. We s elected two fusion reactor designs in the International Thermonuclear Experimental Reactor (ITER), i,e., the Engineering Design Activity (ED A) and the Conceptual Design Activity (CDA), The ITER/EDA will adopt b eryllium for the plasma-facing component (PFC), and the ITER/CDA adopt ed graphite for PFC. The beryllium dust production in the ITER/EDA rea ctor will range from 7.0 to 10.3 kg/disruption, which strongly depends on vapor shield effects. The carbon dust production in the ITER/CDA r eactor will range from 1.9 to 2.4 kg/disruption. However the carbon du st will increase by as much as a factor of 2 to 5 because the effectiv e latent heat of graphite has a large uncertainty under the extremely high heat flux during disruptions. For both, dust production from the first wall depends on the current quench time during disruptions. If t he current quench time can be extended, the beryllium dust from the fi rst wall will be minimized, and the carbon dust from there will be neg ligible.