An assessment of UO2 and ATF concept fuel performance modeling demands against current experimental capabilities under LOCA conditions

Abstract

This paper compiles and digitizes the publicly reported data for integral loss of coolant accident (LOCA) testing so it can be used by both multiphysics modeling and simulation groups and experimental groups. Specifically, this paper compiles the reported rodlet geometries, burst conditions, reactor operating conditions, and instrumented measurements from several test campaigns, including the KfK’s FR2, PBF’s LOC, PHEBUS, ANL, Studsvik, Halden IFA-650, and ORNL SATS LOCA series. Openly accessible data for LOCA experiments, especially those using high burnup UO2 or ATF concepts, are limited and inconsistent in instrumentation, resulting in highly empirical models that lack the necessary accuracy when predicting fuel performance under LOCA conditions. Available fuel performance codes that integrate models for high burnup UO2 and ATF concepts under LOCA conditions include BISON, FAST, and FALCON. This paper assesses the inputs, boundary conditions, and experimental demands informing the thermomechanical model options for each fuel performance code. Following comparisons between experimental LOCA capabilities and current modeling demands, informed recommendations to bridge the gaps between experimentation and modeling capabilities include detailed reporting of fuel rod geometries, reactor conditions, and axially dependent power and temperature profiles in addition to continued LOCA testing with expanded instrumentation in advanced testing facilities.