Lead coolant modeling in system thermal-hydraulic code HYDRA-IBRAE/LM and some validation results

Abstract The paper overviews the challenges associated with the development of a system thermal-hydraulic code applied for lead coolant by the example of a Russian system thermal-hydraulic code HYDRA-IBRAE/LM. It presents the PIRT describing relevant thermal-hydraulic phenomena that are to be simulated to model operational transients and accidents of Russian lead-cooled reactor BREST-OD-300. The paper also mentions the points in favor of using three-fluid model as a basic one. The results of evaluation and selection of lead coolant closure relations, that could be used in system thermal-hydraulic code, are presented. The paper demonstrates that heat transfer in the lead coolant may be calculated using closure relations obtained for the other liquid metal coolants introducing correction factors depending on the value of contact thermal resistance caused, for example, by oxide films present at the surface. The paper presents recommended properties of the lead coolant and summarizes experimental research findings of the Russian project PRORYV that can be used to validate system thermal-hydraulic codes. The paper discusses validation results for HYDRA-IBRAE/LM code based on experiments carried out using a BREST-OD-300 steam generator model and those with lead coolant cooldown due to argon injection.