Enhancing cladding mechanical modelling during DBA/LOCA accidents with FRAPTRAN: The TUmech one-dimensional model

The analysis of the cladding mechanical performance is essential for predicting rod failure during the heat-upphase of a loss-of-coolant accident (LOCA). Previous modelling and simulation exercises have shown thatthere is room for improvement in the accuracy of fuel performance simulations under such conditions. In thiswork, TUmech, a simplified standalone version of the mechanical model in TRANSURANUS, has been developedand coupled with FRAPTRAN-2.0. After highlighting the most significant differences between both approaches,particularly in their mechanical treatment and material property correlations, simulations have been performedfor IFA-650.2 (fresh fuel) and IFA-650.10 (high burnup fuel) of the Halden LOCA test series. The results obtainedfrom both FRAPTRAN versions have been compared with experimental data and benchmarked against TRANSURANUS estimates, focusing on rod inner gas pressure, post-test cladding outer diameter, and burst time.In both scenarios, FRAPTRAN-TUmech has proven to enhance the accuracy in predicting these three variablescompared to the FRAPTRAN default version. However, further validation is required before drawing definitiveconclusions based on the encouraging results.

ARAGÓN GRABIEL Pau;  FERIA Francisco;  HERRANZ PUELA Luis Enrique;  SCHUBERT Arndt;  VAN UFFELEN Paul; 

2024-03-26

PERGAMON-ELSEVIER SCIENCE LTD

JRC135195

0149-1970 (online),   

https://www.sciencedirect.com/science/article/pii/S0149197024001392?via%3Dihub,    https://publications.jrc.ec.europa.eu/repository/handle/JRC135195,   

10.1016/j.pnucene.2024.105189 (online),