Simulation of a CANDU 6 Containment Leakage Rate Test Using Melcor

Abstract

In general, it is difficult to validate a code input model for a nuclear power plant due to limitation of available test data. As an effort to overcome this weakness, it was tried to simulate a containment leak rate test at a CANDU 6 plant. For this purpose, a MELCOR model of the containment consisting of 51 control volumes was developed. Leakages were assumed to occur at the volumes surrounding the containment wall. The initial conditions were set to the test data at a time when the atmospheric stabilization was achieved. Then simulation was carried out until the end of the main test period. The results show under-estimation of pressure and temperature following rapid decrease at the early stage. Sensitivity study is further needed for the effect of the heat structure model. Even though this simulation gives several insights on modeling and the test method, the applicability seems to be limited.