The CATHARE 2 thermal hydraulics system code has been developed by the CEA, EDF, FRAMATOME-ANP and the IRSN since 1979. Three different kinds of application of CATHARE 2 are performed at the IRSN. They are illustrated in this paper.
CATHARE 2 is used at the IRSN for safety assessment, as a direct support of its expertise activity. Examples given concern French PWRs safety (inherent boron dilution in case of a Small Break LOCA, Large Break LOCA safety analysis methodology) and VVERs safety.
The IRSN performs additional validation of CATHARE 2, to improve the code capabilities and evaluate the uncertainties. The paper presents these activities in the framework of the international OECD/CSNI SETH and BEMUSE projects.
CATHARE 2 is used by the IRSN for R&D purposes, namely methodology and code developments. Its application as a reference tool in the PSA (Probabilistic Safety Assessment) level 2 project for the accident front-end thermal hydraulics is presented. Moreover, the IRSN has coupled its core degradation code, ICARE2, with the standard version of CATHARE 2, in order to obtain a best-estimate severe accident code that is also used in the PSA-2. CATHARE 2 is also the basic tool for the analysis of the behavior of high burn up fuel under LOCA conditions.
Thanks to its reliability and its high level of validation, CATHARE 2 fully contributes to the achievement of the IRSN missions: expertise, technical support, methodology and research.