Parametric model for analysis of melt progression in U-A1 assemblies.

摘要

A computational model has been developed that calculates the thermal degradation of the reactor core of the production reactors at the Savannah River Site (SRS) under postulated severe accident conditions. This model addresses heatup and degradation of the U-Al fuel and Li-Al or U-metal target assemblies and neighboring structures. Models included are those for assembly heatup due to decay heat generation, material melting and relocation, volume expansion of fuel due to foaming and melt/debris accumulation in assembly bottom end-fittings. Sample results are presented that illustrate the effect of alternative assumptions regarding the temperature at which U-Al alloy melts and relocates and the extent to which fuel foaming thermally couples adjacent fuel and target tubes. 5 refs., 6 figs., 1 tab.