Calendar of Events
Development of a Neutronics/Thermal-Hydraulics/Fuel thermo-mechanics Multi-physics System Tool for Best Estimate PWR Core Simulations
2. OG, Raum 302
Neutronics/thermal-hydraulics coupled simulations have become a standard in the last decade; however, the impact of the detailed description of the fuel behaviour on coupled calculations has only recently started to be considered.
A wide range of variation of the fuel gap conductance and fuel conductivity during the life of the fuel rod, and the important feedback of these properties on the fuel and coolant temperature, suggest that a detailed modelling of the fuel behaviour must be considered in a best estimate simulation. To this purpose, a multiphysics tool coupling the neutronics code PARCS, the subchannel TH code SUBCHANFLOW and the thermos-mechanics code TRANSURANUS was developed.
Taking advantage of the neutronics and subchannel TH coupling, a methodology was created for the extraction of local safety parameters. The methodology solution was compared against a higher order solver showing good accuracy in the predictions in a much lower computational time.
With the fully coupled tool and having a detailed model of the fuel which considers also pre-irradiation effects, a UO2/MOX PWR reactivity initiated accident (RIA) transient was analysed. The fuel temperature and RIA transient power peak showed a significant deviation when compared to simpler models. The studies performed shed light on the complex physical behaviour occurring in the transient scenario, stressing the importance of the detailed modelling of the fuel behaviour on a safety related simulation such as RIA.
The new developed multiphysics coupled tool, PARCS-SCF-TU, paves the way for the best estimate analysis of nuclear reactor cores.
Joaquin Rubén Basualdo Perelló
Karlsruher Institut für Technologie