VALIDATION OF A COMPUTATIONAL MODEL FOR THE EVALUATION OF FUEL-COOLANT INTERACTION UNDER SEVERE ACCIDENTAL CONDITION IN FAST BREEDER-REACTORS

A computational model for fuel-coolant interaction has been validated through calculations for a series of THINA experiments. By the experim ents, it was intended to simulate a comparatively massive injection of molten core materials into sodium pool under a core disruptive accide ntal condition assumed for fast breeder reactors. The calculations by the SIMMER-II code showed that the current models for the fuel-coolant interaction (FCI) had the capability to well reproduce the experiment al results. This means that the SIMMER-II FCI model based on the liqui d particles size and the heat transfer among liquid components is vali d with proper accuracy for the estimation of a FCI even without more d etailed mechanistic model for FCI. In particular, the thermal-to-mecha nical energy conversion rates were well predicted. (C) 1998 Elsevier S cience Ltd. All rights reserved.