Transient Behavior of Low Enriched Uranium Silicide and Aluminide Miniplate Fuel for Research Reactors

Abstract

This paper describes the results of transient experiments using a low enriched uranium silicide (density, 4.0 g U/cm3) and aluminide (density, 2.2 g U/cm3) miniplate fuels prepared for the Japan Research Reactor-3 (JRR-3). The transient irradiation was performed in the Nuclear Safety Research Reactor (NSRR) at the Japan Atomic Energy Research Institute (JAERI). The results obtained are summarized below. 1. The tested silicide miniplate fuel, which will be a candidate for a future low enriched fuel in the JRR-3 core, did not fail with an energy deposition of 106 cal/g·fuel at a peak cladding surface temperature (PCST) of 508°C. This condition simulated a transient causing blister failure, which was assumed to occur above the PCST of 400°C. Accordingly, the tested silicide miniplate fuel had a strong resistance against blistering up to 508°C.2. The tested aluminide miniplate fuel did not fail with an energy deposition of 55cal/g· fuel at a PCST of 230°C. This condition simulated an accidental water channel closure, which was assumed in the safety analysis of JRR-3. The predicted PCST by using the EUREKA-2 code was about 150°C. Accordingly the conventional aluminide fuel used in JRR-3 was found to be intact under a simulated water channel closure accident.