In vessel corium propagation sensitivity study of reactor pressure vessel rupture time with PROCOR platform

The problem of corium propagation for PWRs in the Reactor Pressure Vessel (RPV) and the timing of RPV failure is one of the main issues of study in the area of severe accidents. The PROCOR numerical platform created by the CEA severe accident laboratory is modelling corium propagation for LWRs, its relocation to the Lower Plenum and RPV failure. The idea behind the platform was to provide a tool that is fast enough to be able to perform numerous calculations within a reasonable time frame in order to deliver a statistical study. Work on the development of models that describe in-vessel issues is being pursued through simplified phenomena modelling, their verification and sensitivity studies. Recent activities related to PROCOR development involved cooperation between French CEA experts and Polish PhD students, who were engaged in the topics of core support plate modelling and analysis of the phenomena occurring in a thin metallic layer on top of the corium pool. Those issues were identified as strongly influencing the course of severe accidents and the timing of RPV failure. In some sensitivity studies performed on a given generic high power Light Water Reactor with heavy reflector, two groups of RPV ruptures were distinguished related to the two issues, which provided motivation for further work on these topics. The paper will present a sensitivity study of corium propagation in order to identify the relevance of those two issues for the timing of RPV rupture.

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Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017).