Ion Chromatographic Decontamination of ¹³⁷Cs-enriched Fly Ash Using Poly(vinyl alcohol)-bound Copper Ferrocyanide as Cs Adsorbent

¹³⁷Cs decontamination

環境放射能除染学会

環境放射能除染学会誌

Poly(vinyl alcohol)-bound granulated copper ferrocyanide was found to be a Cs adsorbent suitable for ion chromatographic elimination of Cs from the water extract of ¹³⁷Cs-enriched fly ash that was generated by pyroprocessing decontamination of ¹³⁷Cs-contaminated solid wastes. The troublesome leakage of cyanide compounds during the chromatographic process was suppressed by the use of the organic binder. The adsorbent adsorbed 67 g/kg of Cs from the extract of the fly ash containing 10⁵ times of Na⁺ ions and 3×10⁴ times of K⁺ ions with respect to Cs⁺ ions. Since ¹³⁷Cs-enriched fly ash containing 11 mg/kg of Cs and most of Cs was water-soluble, the ion chromatographic elimination reduced the weight of the radioactive waste by a factor of more than 5,000. ¹³⁷Cs-contaminated solid wastes before pyroprocessing decontamination generally contains a few ppm of Cs, so that the total weight reduction factor of more than 10,000 can be easily attained by pyroprocessing decontamination and subsequent ion choromatographic decontamination using poly(vinyl alcohol)-bound copper ferrocyanide as a Cs adsorbent.