Abstract: Since the fast reactor core is not in the maximum reactivity configuration, a hypothetical core disrup-tive accident could lead to the prompt criticality due to a change in the core material configuration, and the resulting energy generation has been one of the issues in fast reactor safety, and therefore appro-priate measures are needed to mitigate and contain the effects of the energy generated in the acci-dent. In order to assess the effectiveness of these mitigation measures, a set of computer codes for the analysis of event progression and energy generation behavior in the ATWS of fast reactors has been developed, maintained, and improved under international collaboration at JAEA. Since the important physical phenomena governing the event progression vary as the accident pro-gresses, the entire accident process in accident analysis is divided into several phases in the analysis of accident, and dedicated analysis methods are provided for each phase to analyze the event pro-gression in each phase. The organization and overview of these analysis methods will be presented in this seminar. As a representative example of the validation approaches in the application of these analysis methods to the reactor safety assessment in the licensing procedure in Japan, the validation studies to confirm the applicability to reactor analysis of the SIMMER code for the analysis of core material movement and reactor power, which is important for the analysis of energy generation in the accident, will be presented. The validation studies of the SIMMER code have confirmed the applicability of SIMMER to the reactor analysis, while at the same time identifying the critical phenomena whose effect of their uncertainty in the reactor analysis should be checked.

Referent/in
Herr Yoshiharu Tobita

Karlsruher Institut für Technologie
Campus Nord, INR

Veranstalter
Institut für Neutronenphysik und Reaktortechnik, INR
Karlsruher Institut für Technologie
Hermann-von-Helmholtz-Platz 1
76344 Eggenstein-Leopoldshafen
E-Mail: ingeborg schwartz ∂does-not-exist.kit edu

Zielgruppe
Alle, Schüler*innen, Forscher*innen