MODELLING OF ZIRCALOY CLADDING HYDRIDING IN HIGH BURNUP FUEL TESTS (PREPRINT IBRAE-1999-08)

Preprint IBRAE-99-08

Veshchunov M.S. 

Modelling of the complicated behaviour of hydrogen in the oxidising Zry cladding observed in the high burnup fuel tests, is attempted. The developed model is based on the previous approach to the description of the hydrogen penetration mechanism through the growing oxide scale of the Zr cladding, self-consistently combined with modelling of the multicomponent (hydrogen-oxygen) diffusion in the two-phase zone (hydrides in the metal matrix). As a result, this allows natural explanation of the observed steep spatial gradients in the hydride distribution over the Zr cladding, leading to the brittle mechanical behaviour of the cladding and PCMI failure of the high burnup fuel rods. 

Bibliographical reference

Veshchunov M.S. MODELLING OF ZIRCALOY CLADDING HYDRIDING IN HIGH BURNUP FUEL TESTS. Preprint IBRAE-99-08. Moscow: Nuclear Safety Institute. November 1999. 14 p. — Refs.: 19 items.