Abstract
The separation of fission products from irradiated UO2 in fused nitrate systems was studied by the following procedure:
Dissolution of UO2 in fused NH4NO3; adsorption of fission products on glass powder; fused salt chromatography with γ-Al2O3; evaporation from fused nitrates; and precipitation of U-compound (probably alkali uranate, M2U2O7) in a fused LiNO3-KNO3 mixture. Radiochemically pure Zr-Nb was selectively separated from the fused NH4NO3 melt by adsorption. Ru and I were completely evaporated from fused LiNO3-KNO3 mixture at above 280°C and from fused NH4NO3 at above 240°C, respectively. By means of chromatography with a γ-Al2O3 column, Zr-Nb and rare earths were completely separated from U in fused NH4NO3 or fused NH4NO3-LiNO3 medium at 150°to 180°C, and further, Cs, Ba and Ru were also expected to be separable from U under suitable condition. When the U-compound was precipitated in fused LiNO3-KNO3 at 350°C, Cs, Sr, Ba and Ru were fairly well separated from U.
