An efficient model for the analysis of fission gas release

• Published in: Journal of nuclear materials 2002-04, Vol.302 (2), p.125-134
• Main Authors: Bernard, L.C., Jacoud, J.L., Vesco, P.
• Format: Article
• Language: English
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; F0500; F0700; Fission nuclear power plants; Installations for energy generation and conversion: thermal and electrical energy; T0100; U0200
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/S0022-3115(02)00793-6

This paper presents the fission gas release (FGR) model that has been developed at Framatome ANP and incorporated into its fuel rod performance code COPERNIC in order to accurately predict FGR into pressurized water reactor fuel rods under normal and off-normal operating conditions including UO 2, gadolinia and MOX fuels. The model is analytical, thus enabling fast and robust fuel rod calculations, a must within an industrial framework where safety evaluations may require the analyses of a full core and of a very large number of transients. Although the model is simple, it includes the most important FGR features: athermal, thermal, steady-state, and transient regimes, burst effect, rim formation, and MOX-type microstructure. The validation of the model covers 400 irradiated rods that include high burnups, high powers, short to long transients, and shows the quality of the prediction of the model in all types of conditions. As temperature is a key parameter that affects FGR, the COPERNIC thermal model is briefly described and its impact on fission gas released uncertainty is discussed.