Measures against containment overpressurization and their thermodynamic efficiency: Chapter 3

Overpressurization of a containment has to be expected not before about three to five days after start of the accident. According to the results of the German Risk Study, the failure mode ''overpressurization'' is expected to be the most probable one with a relative probability of more than 90% in case of a meltdown accident. Because of the high contribution of overpressurization to the total likelihood of containment failure, several measures like ''Filtered Vented Containment'' have been proposed in the past, to avoid or delay containment overpressurization. In this paper the thermodynamic efficiency of such additional measures are discussed. Results are given for accident sequences with low or high system pressure scenarios during the in-vessel-melt