ASTEC V2. Overview of code development and application at GRS

The integral code ASTEC (Accident Source Term Evaluation Code) commonly developed since 1996 by the French IRSN and the German GRS is a fast running programme, which allows the calculation of entire sequences of severe accidents (SA) in light water reactors from the initiating event up to the release of fission products into the environment, thereby covering all important in-vessel and containment phenomena. Thus, the main ASTEC application fields are intended to be accident sequence studies, uncertainty and sensitivity studies, probabilistic safety analysis level 2 as well as support to experiments. The modular structure of ASTEC allows running each module independently and separately, e.g. for separate effects analyses as well as a combination of multiple modules for coupled effects testing and integral analyses. Subject of this paper is an overview of the new V2 series of the ASTEC code system and presentation of exemplary results for the application to severe accidents sequences at PWRs. (orig.)