Study on solubility of transuranium elements, II

Moriyama, Hirotake*

JNC TJ8400 2000-050, 47 Pages, 2000/03

JNC-TJ8400-2000-050.pdf:1.49MB

In support of the safety assessment of geologic disposal of high levcl radioactive wastes, the solubility of transuranium elements was studied. The solubility of PuOxHO was measured undcr a reducing condition, and the solubility product K and the stability constant of Pu(OH) were obtained. The obtained K value was found to be much smaller than that predicted by Rai et al. from its dependence on ionic radius. Also, the solubility of PuO3 xHO was measured under an oxidizing condition and the solubility product K was obtained. In the analysis of hydrolysis constants of actinide ions, it was found that the systematic trend of the hydrolysis constants was well explained by the hard sphere model considering the effective charges of actinide ions.

Development of fluid-rigid strongly coupled particle method for the estimation of the relocation behavior of damaged in-core structures

Fukuda, Takanari; Yoshida, Hiroyuki

no journal, , 

The presenters have developed a new fluid-rigid coupled particle method for the estimation of the relocation of in-core structures mechanically interacting with fluid phases existing in a reactor. Amid a severe accident, there might exist relatively large in-core structure, the scale of which is comparable to that of the maximum spatial scale of the fluid (e.g. scale of containment vessel). Such a calculation configuration can result in numerical instability with the conventional fluid-rigid weakly coupled methods. Hence, we have derived fluid-rigid strongly coupled time-development equations on the basis of Hamilton's least action principle and developed a new particle method for solving those equations numerically.