PARCS-Subchanflow-Transuranus multiphysics coupling for improved PWR's simulations

Increasing the prediction accuracy of the simulators' solvers is a constant effort in the nuclear academic and industry communities. In an evolutionary approach, the NRC's neutronics core simulator PARCS is being integrated with KIT's subchannel code Subchanflow (SCF) and JRC Karlsruhe's fuel behavior code Transuranus (TU) into a single code, PARCS-SCF-TU. A loose, nodal level coupling using the Operator-Splitting (OS) technique was implemented. So far, the 2-way steady state solution has been implemented and the transient coupling is under development. Having Transuranus in the coupling allows a better modeling and feedback of the fuel and clad temperature taking into account the local thermal hydraulics and burnup conditions. One of the objectives of this coupling is the future modeling of the RIA accident for high burnup conditions, where the fuel behavior properties and fuel temperature modeling are of relevant importance. In this paper, results obtained with PARCS-SCF, PARCS-SCF-TU and PARCS standalone for the PWR MOX/UO2 core transient benchmark as part of the testing and verification of the multiphysics codes under development will be presented and discussed. Also, preliminary PARCS-SCF-TU results showing the impact of modeling the fuel temperature with a fuel behavior code will be given. (author)