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Description
TEVA resin was found to be inefficient for Zr separation in Ca rich matrices. Two alternative resins TBP and UTEVA resin were evaluated as replacements. For both resins it's possible to load sample
in 8-10 M HCl and retain Zr, meanwhile Ca is not retained.
TBP resin does not only retain Zr in given conditions, but it also retains Nb and Fe, which are also eluted Zr with 4 M HCl. Hence anion-exchange pretreatment of sample is required. Combination of anion-exchange pretreatment + TBP separation provided 70+ % yields for sludge, ashes and concrete, although its capacity decreased with increasing sample load.
UTEVA does not retain Fe in given conditions. Nb is retained, but it is not eluted with 4 M HCl. As a result, the anion exchange pretreatment was not strictly required, though it was applied in some cases to further stabilise the separation. The combined anion exchange + UTEVA approach produced yields above 80 % across all tested matrices. When assessing resin capacity leachate with high dissolved concrete content was used. TBP achieved only a 21 % Zr yield for 10 ml of leachate, whereas UTEVA reached an 89 % yield for 15 ml of leachate, demonstrating superior performance.
These results show that UTEVA resin is the optimal choice for Zr separation in complex, Ca rich matrix commonly encountered in nuclear decommissioning samples.