Davide Pizzocri, Alessio Magni, Lelio Luzzi
Politecnico di Milano, Italy.
Predicting the evolution of stable and radioactive fission gases accumulated in the fuel rod free volume is of primary interest for the fuel rod analysis and the assessment of the gap activity, when evaluating the radiological consequences of postulated accidental scenarios (e.g., LOCA, SGTR). We select a set of integral experimental tests on LWR fuel rods, i.e., the CONTACT and the HATAC experiments, focused on the behaviour of stable and radioactive fission gases during stationary irradiation and power cycling conditions, respectively. We provide the simulated performance of the irradiated fuel rods with the thermo-mechanical code TRANSURANUS coupled with the SCIANTIX module for fission gas behaviour. The latter is an open-source multi-scale code for the mechanistic modelling of stable and radioactive fission gases. The results of the simulations point out the advantages brought about by the multi-scale code suite TRANSURANUS/SCIANTIX. The predictions of stable and radioactive fission gas release show a satisfactory agreement with the measurements available from both CONTACT and HATAC irradiations (within the accepted uncertainty range for fission gas release in fuel performance codes, i.e., a factor of 2), in terms of amount, kinetic and release rate of fission gases.
Event Timeslots (1)
Wednesday – 15th September 2021