Simple physics-based modelling of fission gas swelling and release in UO2 applied to integral fuel rod analysis

An integrated model is developed for analysing the coupled and stress-dependent phenomena of fission gas swelling and release in UO2 fuel during irradiation. The model practically combines a physics-based treatment and a level of simplicity consistent with the uncertainties and the computational efficiency requirements pertaining to integral fuel rod thermal-mechanical analysis. The emphasis is on the modelling of the grain-face gas bubble development and its dependence on the local hydrostatic stress, which is of special importance for the analysis of the fuel behaviour during power ramps and pellet-cladding mechanical interaction conditions. The applicability of the new model to integral fuel rod analysis is verified through implementation and testing in the TRANSURANUS fuel rod analysis code. In the frame of the IAEA co-ordinated research project on Fuel Modelling at Extended Burn-up FUMEX-III, the model is employed for the simulation of irradiation experiments from the OECD/NEA International Fuel Performance Experiments database, showing a physically sound representation of the relevant phenomena. The comparison of the results with the available experimental data of fission gas swelling and release at moderate burn-up is presented as a first step of validation, pointing out an encouraging predictive accuracy for different irradiation conditions, without applying any fitting to the model parameters.

PASTORE Giovanni;  LUZZI Lelio;  DI MARCELLO Valentino;  VAN UFFELEN Paul; 

2013-01-14

ELSEVIER SCIENCE SA

JRC70836

0029-5493,   

http://www.sciencedirect.com/science/article/pii/S0029549312005754,    https://publications.jrc.ec.europa.eu/repository/handle/JRC70836,   

10.1016/j.nucengdes.2012.12.002,