Modeling of fission product release from HTR fuel for risk analysis

The United States (U.S.) and Federal Republic of Germany (FRG) have developed methodologies to determine the performance of and fission product release from TRISO-coated fuel particles under postulated accident conditions. The paper presents a qualitative and quantitative comparison of U.S. and FRG models. The models are those used by General Atomics (GA) and by the German Nuclear Research Center at Juelich (KFA/ISF). A benchmark calculation was performed for fuel temperatures predicted for the U.S. Department of Energy (DOE) sponsored Modular High-Temperature Gas-Cooled Reactor (MHTGR). Good agreement in the benchmark calculations supports the on-going efforts to verify and validate the independently developed codes of GA and KFA/ISF. This work was performed under the US/FRG Umbrella Agreement for cooperation on gas-cooled reactor (GCR) development.