An improved thermal-hydraulic modeling of the Jules Horowitz Reactor using the CATHARE2 system code

•An improved thermal-hydraulic modeling of the JHR reactor is described.•Thermal-hydraulics of the JHR is analyzed during loss of flow accident.•The heat exchanger approach gives more realistic and less conservative results.

The newest European high performance material testing reactor, the Jules Horowitz Reactor, will support current and future nuclear reactor designs. The reactor is under construction at the CEA Cadarache research center in southern France and is expected to achieve first criticality at the end of this decade. This paper presents an improved thermal-hydraulic modeling of the reactor using solely CATHARE2 system code. Up to now, the CATHARE2 code was simulating the full reactor with a simplified approach for the core and the boundary conditions were transferred into the three-dimensional FLICA4 core simulation. A new more realistic methodology is utilized to analyze the thermal-hydraulic simulation of the reactor during a loss of flow accident.