Thermohydraulic Calculation of the Design of an Irradiation Device for In-Reactor Tests of VVER-SCP Fuel Rod Models with Cores Based on Nuclear Fuel Swelling Simulators

One of the promising projects of the generation IV reactors is water-cooled power reactors with supercritical coolant pressure (VVER-SCP), which is capable of increasing the efficiency of VVER power units by increasing the pressure to 23.5–25 MPa and increasing the coolant temperature to 380–540°C. One of the main problems that will have to be faced when developing the VVER-SCP project is the selection of cladding materials for a fuel element capable of operating at supercritical coolant parameters. To solve this problem, it is necessary to conduct in-reactor tests and post-reactor studies of candidate structural materials for fuel element cladding. For this purpose, it is necessary to develop an irradiation device that could ensure in-reactor tests of candidate structural materials for fuel element cladding under SCP coolant conditions. In the study, thermal hydraulic calculations of the irradiation device design have been carried out using the SolidWorks software package. The results of calculations have shown that this design of the irradiation device will allow for in-reactor testing of VVER-SCP fuel rod layouts at supercritical coolant parameters in the SM-3 research reactor facility.