Within the frame of ASTRID (Sodium cooled Fast Reactor) prototype development, update of calculation methodologies using new generation of codes benefiting from High Performance Computing (HPC) and advanced coupling capabilities is underway. These methods are expected to be integrated in ASTRID safety demonstration. In particular, development of coupled neutronics/thermal-hydraulics/fuel mechanics methodologies during accidental transients is underway.
Coupling Neutronics and thermal-hydraulics in double phase flow conditions (either sodium + vapor sodium or sodium + other gaz) can be used for:
• Loss of Flow transients (LOF, sodium + vapor sodium)
• Gas insertion transients.
This coupling is of special interest with cores strongly relying on axial leakage for safety consideration (like CFV cores [ICAPP11]).
The work proposed is to further develop the implementation of 3D coupling with state of the art CEA codes (APOLLO3, FLICA, CATHARE, TRIO etc.) to analyze the two type of transients stated above.