Application of the MELCOR for Fusion Code to the Transient Accident Analysis of the IFMIF-DONES Test Cell

According to the European Fusion Roadmap, to demonstrate the feasibility of fusion energy, it is necessary to build a comprehensive database of materials properties to be used in future fusion power plants. This is the objective of the IFMIF-DONES facility, which will drive a deuteron beam on a liquid lithium target to produce high energy neutron fluxes for irradiating candidate fusion materials. Among the several ongoing activities in the frame of the EUROfusion Early Neutron Source Work Package (WPENS) project, deterministic accident analyses play an important role, since they help identifying a set of reference accident scenarios and related safety class components. Some of these scenarios are being studied with the MELCOR-fusion code, an integrated engineering code which is able to perform thermal-hydraulic transient calculations. In this work, the MELCOR-fusion code has been applied to two potential accident scenarios involving the degradation of the primary lithium loop of IFMIF-DONES. A rupture in the Quench Tank and a break in the inlet nozzle to the Target Vacuum Chamber were postulated as the two initiating events followed by a lithium spill into the Test Cell room. The purpose of this study was to obtain different key metrics, such as the maximum pressure and temperature loads reached in the TC room, the amount of the leaked lithium mass, and the time for lithium solidification. The computed results will help identify the safety requirements to be applied to the final design of the TC room.