Comprehensive Safety Analysis Code System for Nuclear Fusion Reactors IV: 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 thermal characteristics of fusion reactor structures simultaneously. We selected two fusion reactor designs in the International Thermonuclear Experimental Reactor (ITER), i.e., the Engineering Design Activity (EDA) and the Conceptual Design Activity (CDA). The ITER/EDA will adopt beryllium for the plasma-facing component (PFC), and the ITER/CDA adopted graphite for PFC. The beryllium dust production in the ITER/EDA reactor 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 reactor will range from 1.9 to 2.4 kg/disruption. However, the carbon dust will increase by as much as a factor of 2 to 5 because the effective 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 the current quench time can be extended, the beryllium dust from the first wall will be minimized, and the carbon dust from there will be negligible.