Thermal fluid-structure interaction analysis of shield plug, 1; Preliminary analysis by FINAS and AQUA

Doi, Yoshihiro; Ohira, Hiroaki

A thermal fluid-structure interaction analysis is being conducted to develop numerical simulation method for the temperature distribution in the shield plug of LMFBRs. As for the preliminary analyses, the structural temperature distribution in the shield plug and the thermohydraulic characteristics in the cover gas region were calculated separately FINAS and AQUA, respectively. The calculated temperature of FINAS at the bottom of the shield plug by the thermal conduction model was 150C to 200C lower compared to the data measured in MONJU during start-up tests. This large temperature discrepancy was improved to the order of 60C by the implementation of the thermal radiation model. In addition, the thermohydraulic analysis in the cover gas region by AQUA showed that the azimuthal temperature differences induced by natural convection were about 40C in the cover gas region and about 20C in the inner annulus. However, the maximum temperature difference of about 100C was observed in the inner annulus along the azimuthal direction. These facts indicate that the thermal fluid-structure interaction analysis is strongly expected to simulate the complex heat transfer phenomena in the shield plug induced by the mixture of conduction, radiation and natural convection.