Estimated Substantiation of the Design of an Irradiation Device for Testing Microspherical Fuel in the SM-3 Reactor to Determine the Yield of Fission Products

One of the innovative projects for Generation IV reactors is the high-temperature gas-cooled reactor, which is capable of producing heat with a coolant temperature of up to 950–1000°C. This allows the generation of hydrogen and other useful products without CO2 emissions. A distinctive feature of such reactors is the use of micro fuel rods dispersed in a graphite matrix: fuel compact. For the industrial implementation of high-temperature gas-cooled reactors, it is necessary to conduct research on the reliability and performance of their components. Therefore, one task is to study fuel compacts (FCs) with microspherical fuel. To address this task, reactor tests and postreactor studies of fuel compacts with micro fuel rods need to be conducted. To carry out reactor tests of FCs in a helium environment, it is essential to develop a capsule irradiation device that will allow sampling the gas medium from the cavities containing the FCs for analyzing the dynamics of fission product release from the micro fuel rods. This work presents the justification for the design of the irradiation device for conducting reactor tests of fuel compacts with microspherical fuel, with the capability for operational analysis of the radioisotopic composition of the gas medium in which the fuel compacts are placed, using semiconductor gamma spectrometers.