ANALYSIS OF TOTAL INSTANTANEOUS BLOCKAGE ACCIDENT FOR CHINA EXPERIMENTAL FAST REACTOR

摘要

Chinese Experimental Fast Reactor (CEFR) is under construction in China. It is essential to investigate core disruptive accidents (CDAs) for the evaluation of CEFR's safety characteristic and acquiring licenses. Accident of total instantaneous blockage, one of design basis accidents for CEFR, was modeled and analyzed. The degradation scenario was calculated by a fluid-dynamics analysis code for liquid-metal fast reactors (LMFRs). The subassembly scale was simulated and calculated for detail investigation of accident process. Total instantaneous blockage was assumed to occur in one assembly under normal operating conditions and consequences to neighboring assemblies were studied. The result shows that the key events such as sodium boiling, clad melting, fuel particles relocation, hexcan failure and melt propagation into inter-assembly gap were adequately simulated. It can help to give a better understanding also prediction and mitigation capability of hypothetical accident scenario in subassembly blockages.