Evaluation of dissolution rate on high plutonium content MOX fuel

not registered; Endo, Hideo; Ogasawara, Masahiro*; Shinada, Masanori*; not registered

The dissolution rate of high Pu content MOX fuel into the nitric acid was measured as a function of Pu content. MOX fuel sample which was pressed and sintered, were dissolved in boiling 7M nitric acid, and dissolution rate was measured by analysis of the Pu and U concentration in the solution. Dissolution rate of MOX fuel had the following tendencies : it decreased with increase of the Pu content and was reduced after 6 hours dissolution. These results agreed well to previous one, but dissolution rate was 3-6 times larger than that. It is estimated that the cause of this difference was due to the underestimate of surface area of MOX fuel powder and the difference of MOX O/M ratio.