Status of CATHARE code for sodium cooled fast reactors

Sodium cooled fast reactors (SFRs) have been developed in France for nearly 50 years with successively Rapsodie, Phenix and Superphenix plants. Nowadays, the so-called Astrid prototype is developed in France in the frame of Generation IV deployment. The Astrid project requires thermal hydraulic inputs to support the design and the safety analysis. One important issue is the plant dynamic analysis which is based on the CATHARE code. The CATHARE code was initially developed in the 1980s for Pressurized Water Reactors in collaboration between CEA, EDF, AREVA and IRSN. The code has been successively adapted to other reactors and recently to SFR. CATHARE code is now the French reference code for SFR applications. The paper presents successively the main characteristics of the CATHARE code and the various elements modified or implemented to adapt the code to SFR characteristics. Coupling of CATHARE code with TRIO_U computational fluid dynamics code is also briefly mentioned for applications where 3D effects can modify the system behavior. The validation process is described, including a review of requirements, the planned program of validation and the present status. Some examples of global validation based on reactor data are depicted, especially the calculation of a natural convection test in Phenix reactor. Other exercises of validation are briefly described as calculations of Superphenix tests.

► The adaptation of CATHARE system code for SFR applications is described. ► CATHARE calculation of Phenix natural convection test is reported. ► CATHARE calculation of a Superphenix trip is briefly reported. ► Coupling of CATHARE with TRIO_U CFD code is presented with a first application.