Influence of daughter radionuclides on Purex-process parameters

Experimental and calculated data are presented which concern the limiting influence of 239Np, 237U, 233Pa, 234Th, 228Th (with daughter radionuclides) on the final decontamination of uranium, plutonium and neptunium from γ-emitters in Purex-process for NPP fuel reprocessing. It was found that in the investigated flowsheet 228Th follows neptunium(IV) and 233Pa accompanies plutonium. The influence of accumulated daughter γ-emitters on ionization characteristics of end products in storage up to 100 years was studied. It is shown that stored regenerated uranium and plutonium may require repeated reprocessing just before refabrication. (author) 2 refs.; 4 figs.; 2 tabs