Development of a multi-physics coupling system based on ICoCo interface and its validation on NEA-OECD core transient benchmark

•The ICoCo-based multi-physics coupling system for nuclear core analysis was developed.•A 3rd-party library is adopted to handle the mesh interpolation and field mapping.•Validation against the benchmark proves the capability of the coupling system. This paper describes the development of a multi-physics coupling system of Thermal-Hydraulics (T-H) code CORTH and reactor dynamics diffusion code CORCA-K for nuclear core analysis. The coupling system is based on a typical server-client coupling system ICoCo (Interface for Code Coupling), where each code is first wrapped by the ICoCo interface and then compiled into a shared library. And a 3rd-party library named MEDCoupling is adopted to handle the mesh interpolation and field mapping between CORTH and CORCA-K. The prediction capabilities of CORCA-K/CORTH are proved by the analysis of the NEA-OECD rod ejection transient benchmark, which proves that the developed coupling system CORCA-K/CORTH has good accuracy in nuclear reactor core transient calculation.