Development of Severe Accident Analysis Code SAMPSON in IMPACT Project

IMPACT is the name of a program and of specific simulation software, which will perform full-scope and detailed calculations of various phenomena in a nuclear power plant for a wide range of event scenarios. The four years of the IMPACT project Phase 1 have been completed, and each analysis module of the prototype version of the severe accident analysis code SAMPSON has been developed and verified by comparison with separate-effect test data. Verification of the integrated code with combinations of up to 11 analysis modules has been conducted, with the Analysis Control Module, to demonstrate the code capability and integrity. A 10-inch cold leg failure Loss of Coolant Accident in the Surry Plant was the assumed initiating event. The system analysis was divided into two cases; one was an in-vessel retention analysis when gap cooling was effective, the other was an analysis of phenomena when the event was extended to ex-vessel due to the reactor pressure vessel failure when gap cooling was not sufficient. U...