SEPARATION OF CESIUM FROM NUCLEAR WASTE SOLUTIONS WITH HEXACYANOFERRATE(II)S AND AMMONIUM PHOSPHOMOLYBDATE

Abstract

The separation of 134, 137 Cs from nuclear power plant low-level waste solutions by ion exchange with potassium cobalt hexacyano-ferrate(II), potassium copper cobalt hexacyanoferrate(II) and ammonium phosphomolybdate was studied. The pH of the waste solutions was 6-13 and the concentrations of sodium and potassium ions were 8 - 2700 and 0.5 - 240 mmol/1, respectively. The distribution coefficient of cesium was determined as a function of pH, sodium and potassium ion concentrations and of the ratio of solution volume to exchanger weight (batch factor). The ion exchange rate of cesium was determined for three exchanger grain sizes and at temperatures of 20, 40 and 60° C. A potassium copper cobalt hexacyanoferrate(II) column was tested for cesium separation from a highly alkaline (pH 13) waste solution containing high concentrations of sodium (2.7 M) and potassium (0.24 M) ions; the 1% breakthrough capacity was very high, 12800 bed volumes.