MYRRHA is a pool-type research reactor under design at the Belgian nuclear research center SCK·CEN. The multi-purpose fast-spectrum MYRRHA reactor is cooled with lead–bismuth eutectic (LBE). ESCAPE is a thermal hydraulic 1/6th-scale model of the MYRRHA reactor developed within the European framework programs THINS and MYRTE. The experiments from ESCAPE are crucial for the design and licensing of MYRRHA. First of all, these experiments can provide information on the flow patterns and heat transport in the different compartments of the reactor. Secondly, the data from the ESCAPE experiments can be used for qualification of thermal hydraulic computer codes that will be applied for analyzing the flow and heat transport in the MYRRHA reactor. Considering the rare and typical conditions in heavy liquid cooled nuclear reactors, thorough validation of these codes against relevant experimental data is a prerequisite before application. This paper presents the approach followed by NRG to model the flow and heat transport in ESCAPE using the Computational Fluid Dynamics (CFD) code STAR-CCM+. CFD analyses for different forced flow conditions are presented and compared with experimental results. The predicted temperature distribution in the pool, core and plena agrees well with the temperature measurements from ESCAPE.
