DESIGN-BASIS JUSTIFICATION OF AN IRRADIATION RIG DESIGN TO TEST MICRO-SPHERICAL FUEL IN THE SM-3 REACTOR TO DETERMINE THE FISSION GAS RELEASE

One of the innovative projects of Gen- IV reactors is a high-temperature gas-cooled reactor able to generate heat with a coolant temperature of up to 950–1000 °C, which makes it possible to produce 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, a fuel compact (FC). The commercialization of high-temperature gas-cooled reactors requires the reliability and performance of their components to be confirmed. Therefore, one of the tasks is to study fuel compacts with micro-spherical fuel (MF). To address this task, reactor tests and post-irradiation examinations of fuel compacts with micro fuel rods shall be performed. To test fuel compacts in a helium environment, a capsule-type irradiation rig shall be designed that allows sampling of the gas environment from cavities with fuel compacts to analyze the FGR dynamics. The paper presents a rationale for the irradiation rig (IR) design to conduct reactor tests of fuel compacts with micro-spherical fuel with the possibility of real-time analysis of the radioisotope composition of the gas environment where the fuel compacts are located using semiconductor gamma spectrometers.

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