Publications

Nuclear Fuel Cycle (NFC) Technology and Policy Program

Advanced Fuel for High Burnup and Proliferation Resistance in Light Water Reactors: Annual Report, Rev. 1

M.S. Kazimi et al.

MIT-NFC-TR-024 (July 2000)

Abstract

A preliminary investigation into the behavior of Th based fuels in a repository environment was started. The solubility of ThO2, particularly the production of the hydroxide species, was investigated from pH 2 through 6. Th-U-Zr oxide ceramics, intended to be both fuel and waste form, were fabricated. Zr was included in the ceramics for chemical stability.

Solubility results show that Th is rather insoluble. Samples in the higher pH range (3.5 through 6) were below the detection limit of ICP-AES. Solubility trends followed an initial estimation based on literature data and estimates. Solubility data at higher pH and under different conditions will be collected in the future.

Inclusion of Zr in ceramics decreased density while addition of Mg binder increased density. EXAFS data show that the ceramics are a heterogeneous mixture of ThO2, ZrO2, and UO2+x. Further studies are planned, and future ceramics will be sintered in a reducing environment.