European validation of the integral code ASTEC (EVITA)

Abstract

The main objective of the European Validation of the Integral Code ASTEC (EVITA) project is to distribute the severe accident integral code Accident Source Term Evaluation Code (ASTEC) to European partners in order to apply the validation strategy issued from the VASA project (4th EC FWP). Partners evaluate the code capability through validation on reference experiments and plant applications accounting for severe accident management (SAM) measures, and compare results with reference codes. The basis version V0 of ASTEC—commonly developed and basically validated by GRS and IRSN—was made available in late 2000 for the EVITA partners on their individual platforms. Users’ training was performed by IRSN and GRS. The code portability on different computers was checked to be correct. A “hot line” assistance was installed continuously available for EVITA code users. The actual version V1 has been released to the EVITA partners end of June 2002. It allows to simulate the front-end phase by two new modules: • for reactor coolant system two-phase simplified thermal hydraulics (five-equation approach) during both front-end and core degradation phases; • for core degradation, based on structure and main models of ICARE2 (IRSN) reference mechanistic code for core degradation and on other simplified models. Other main achievements of the project are up to now: • the EVITA validation matrix focused on main risk issues; • first validation results on PACTEL, STORM and EREC tests; • first plant applications on German 1300 PWR and VVER-440/V230.