MODELLING OF GRAIN FACE DIFFUSION TRANSPORT AND SWELLING IN UO2 FUEL (PREPRINT IBRAE-2002-14)

Preprint IBRAE-2002-14

Berdyshev A.V., Veshchunov M.S.

An advanced model for the grain face transport based on the self-consistent consideration of gas atoms diffusion, sinking to and resolution from bubbles on grain faces, is developed. An important role of grain boundary diffusion of gas atoms to edges before interlinking of inter-granular bubbles, is outlined. The coalescence of face bubbles due to their random migration is considered as the main mechanism of grain face bubbles relaxation. Implementation in the MFPR code of the new model and numerical treatment of  various available data on gas release from irradiated fuel, fuel swelling and grain face microstructure, show a satisfactory agreement of the code predictions with measurements.

Bibliographical reference 

Berdyshev A.V., Veshchunov M.S. Modelling of grain face diffusion transport and swelling in UO₂ fuel. Preprint IBRAE-2002-14. Moscow: Nuclear Safety Institute RAS, June 2002. 19 p. — Refs.: 29 items.