Simulation of large clad creep strains with the TRANSURANUS fuel performance code for LOCA

We analyse the simulation of large clad creep strains by means of the TRANSURANUS fuel performance code. While the first order theory gives very good results for small strains below approx. 5%, large strains - typical in simulations of loss-of-coolant (LOCA) accidents - imply numerical instabilities due to the violation of the volume balances. We carry out creep calculations applying a Norton law that defines creep strains for cladding material under varying stress conditions. Applying different solution methods (analytic solution, fuel performance calculations by TRANSURANUS, and finite element calculations by COMSOL) a sensitivity study is made that draws the attention to the effect of geometry change for large strains. We propose an extension of the algorithm used in TRANSURANUS. The verification against the numerical solution given by COMSOL and the analytic solution shows an excellent agreement of the radial profiles of stresses and strains.

DI MARCELLO Valentino;  SCHUBERT Arndt;  VAN DE LAAR Jacques;  VAN UFFELEN Paul; 

2014-01-13

OECD Halden Reactor Project

JRC79038

http://www.ife.no/en/ife/halden/hrp/meeting-enlarged-halden-programme-group-meeting-2013,    https://publications.jrc.ec.europa.eu/repository/handle/JRC79038,