Ask for a reprint
email :
* Give your email
2012
ACLN
|
G.Martin, P.Desgardin, G.Carlot, M.Vayer, C.Ramboz, T.Sauvage, P.Moretto, H.Khodja, P.Garcia, 'Surface blistering and flaking of sintered uranium dioxide samples under high dose gas implantation and annealing', Defects and Diffusion Forum (2012)
High helium contents will be generated within minor actinides doped uranium dioxide blankets which could be used in fourth generation reactors. In this framework, it is essential to better know from which He content the pellets degradation should begin to occur. First elements regarding this problematic have therefore been gathered in this paper. Sintered uranium dioxide disks have been implanted with helium ions then annealed at various temperatures. Above a concentration of ~ 0.5 at.% and for annealing above 1000°C, optical images of the sample surface revealed swelled grains and exfoliated areas. Nuclear reaction microanalyses and atomic force microscopy observations were performed to demonstrate that helium over-precipitated within the swelled grains. The massive precipitation of the gas leads in these conditions to the blistering of the sample surface and acts as a prelude of its flaking. Irradiations of deuterium ions have also been performed at ambient and a direct flaking of the sample surface was observed, but extremely high doses were needed, showing that the temperature is an essential ingredient to induce the gas migration, its massive precipitation and therefore the fuel degradation.
|
|
|