Rapid determination of 113mCd contamination in ALPS-treated water using HCl-free cation-exchange chromatography

A rapid, HCl-free radiochemical procedure was developed in this study to assess 113mCd contamination in ALPS-treated water samples obtained from the decontamination of contaminated water at Fukushima Daiichi Nuclear Power Station (FDNPS). The chemical purification scheme comprises pretreatment with an EmporeTM chelating disk followed by cation-exchange chromatography, where selectivity was enhanced with elution using thiosulfate. Preliminary experiments using simulated samples demonstrated high recovery of 113mCd (90 ± 2.6%, n = 6). The recoveries of Cd obtained from real ALPS-treated water samples (90 ± 7.8%; n = 18 samples) were consistent with the preliminary results. In addition, the separation procedure was highly effective in removing 60Co, 137Cs, 90Sr, 59Ni, 63Ni, 65Zn, 90Y, 129I, 106Ru, and 125Sb, indicating that the developed method is well suited for selective analysis of 113mCd in ALPS-treated water. The minimum detectable activity of this method is typically below 0.2 Bq L−1 when using a standard liquid scintillation counter, indicating that this method can reliably detect 113mCd contamination when its activity exceeds the regulatory clearance limit (40 Bq L−1). The developed method has been utilized to verify the contamination of 113mCd in ALPS-treated water samples. This rapid and HCl-free analytical technique has been successfully applied to real ALPS-treated water samples, proving its suitability not only for radioanalytical laboratories but also for broader environmental water analysis and monitoring.