ITER divertor ex-vessel pipe break

Abstract

This is a study of a divertor (DV) ex-vessel Loss Of Coolant Accident (LOCA), performed for the ITER reactor. One base case and two parameter studies are performed. The calculations are performed with the fusion MELCOR code. The initiating event, for all three analyses, is a double-ended pipe break in the DV cooling loop, which is postulated to occur in a large diameter pipe at the inlet of the main pump. The break flow is discharged into the Tokamak Cooling Water System (TCWS) vault. This is followed by plasma disruption and a break of the DV heat structure cooling pipes, discharging coolant into the Vacuum Vessel (VV). The results show, that the pressures and temperatures are kept below design limits. The results also show that activated corrosion products (ACP) and tritium are released into the TCWS vault from the coolant water, and that VV dust does not enter into the DV coolant loop, and thus does not reach the TCWS vault.