Study on separation of ¹³⁷Cs from ²³⁵U fission process waste - utilization of silica gel-supported ferrocyanide complex salt for ¹³⁷Cs picking

In connection with the potential domestic demand especially in the fields of industry and nuclear medicine, the separation of ¹³⁷Cs from ²³⁵U fission process waste is to be of interest although its economic value could be a polemic. A preliminary study on the separation of ¹³⁷Cs from the ²³⁵U fission process waste generated in the production of ⁹⁹Mo in P.T. BATAN Teknologi, Serpong, was performed through experiments on ¹³⁷Cs picking from sample solution of the radioactive fission waste (RFW). The presented study is aimed to gain experimental data supporting utilization of the matrix of silica gel-supported ferrocyanide complex salt for the separation of ¹³⁷Cs from RFW. Subsequent step would be the recovery and purification of ¹³⁷Cs as part of production technology of ¹³⁷Cs. The RFW sample was batch-treated with the matrix of silica gel-supported ferrocyanide complex salt which was synthesized from silica gel, potassium hexacyanoferrate(II) and copper(II) chloride. The binding of radioisotopes in RFW on the matrix was observed by γ-spectrometry of the RFW solution before and during the treatment. The results showed that approximately 85% of ¹³⁷Cs could be picked from the RFW sample into the matrix. Less amount of ⁹⁵Zr and ⁹⁵Nb was bound into the matrix. ¹⁰³Ru was slightly bound into the matrix whereas ^141/144Ce and ^129mTe were not. It was observed that by using 0.2 and 0.4 g of matrix for 10 ml of RFW, the amount of matrix influenced the binding quantity of ⁹⁵Zr and ⁹⁵Nb but not that of ¹³⁷Cs. (author)