Thermal-hydraulic pre-test analysis of ICE test section with WA-DHR

This report, carried out at the DIMNP of the University of Pisa in collaboration with ENEA Brasirnone Research Centre, illustrates the thermal fluid-dynamics results of the WA-DHR pre-test analysis. In fact, a WA-DHR heat exchanger bayonet tube will be installed into the ICE test section of CIRCE facility to study decay heat removal from the core of a LFR in case of an accidental event with total loss of the secondary circuit and consequent reactor scram. The thermal-hydraulic behavior of the WA-DHR heat exchanger inside the CIRCE facility was studied by the CFD Ansys FLUENT code, adopting an axial-symmetric domain. Pre-test calculations were performed to investigate the natural circulation heat transfer in heavy liquid metal pool and the cooling capacity of air circulating in the secondary side of the DHR. In steady state conditions the DHR inside ICE is able to remove 40 kW heat power, which represents 5% of the nominal power, thanks to thermal stratification phenomena that in this condition is foreseen inside the downcomer region of the ICE test-section.