Melting Temperature of Irradiated Fast Reactor Mixed Oxide Fuels
The melting (solidus) temperatures of irradiated mixed oxide fuels were measured and the compositions of the fuels on the temperature measurement date were calculated. The fuels contained about 29wt% Pu initially and were irradiated up to 124GWd/t in the experimental fast reactor JOYO. A melting temperature correlation was obtained by an experimental regression analysis using 21 measurements:<BR>Τ<SUB>m</SUB>=3, 133.8-460Χ<SUB>1</SUB>-980Χ<SUB>2</SUB>-0.66Χ<SUB>3</SUB>+0.0013(Χ<SUB>3</SUB>)<SUP>2</SUP>, <BR>where Τ<SUB>m</SUB>, is the expected melting temperature (K), Χ<SUB>1</SUB> the plutonium fraction (Pu/(Pu+U)) and Χ<SUB>2</SUB> the americium fraction (Am/(Pu+U+Am)) at the measurement, and Χ<SUB>3</SUB> the burnup (GWd/t). The equation shows that the melting temperature decreases by 5, 4, and 3K per 10GWd/t at 50, 100 and 150GWd/t, respectively. The effects of actinides, such as Pu and Am, on melting temperature could be explained by an ideal solution model. However, the decreases caused by soluble fission products could not be well explained in terms of the ideal solution model.
- Journal of nuclear science and technology
Journal of nuclear science and technology 35(7), 494-501, 1998-07-25
Atomic Energy Society of Japan