APPLICABILITY STUDY OF Co AND Eu EXTRACTION USING SOLVENT FROM Ca RICH HCl SOLUTION

This study was conducted to treat radioactive acidic wastewater, which contained radioactive 60Co and 152Eu. The wastewater can be generated during a decommissioning project to reduce the volume of radioactive concrete waste from nuclear facilities. With a variety of methods for separating the radioactive nuclides available, we evaluated the separation applicability of the solvent extraction method. From our results, Co and Eu could be easily extracted from the Ca rich wastewater using Cyanex301 (Co extraction (%) 99.8, Eu extraction (%) 99.6) without Ca extraction. On the other hand, Eu could be selectively separated by Cyanex272 (Eu extraction (%) 99.1) without Co and Ca extraction at pH 2-3. Therefore, the extraction method can be tailored according to the target radionuclides present in the wastewater and be selectively applied to the overall treatment process. By extracting radioactive Co and Eu from acidic wastewater to below the discharge criteria, treated wastewater could be regarded as non-radioactive industrial waste, to be economically and easily handled. Moreover, it may be possible to reuse separated Co and Eu for research and industrial applications by realizing waste valorization.

Automated summary

This study aimed to treat radioactive acidic wastewater containing radioactive 60Co and 152Eu. The solvent extraction method was evaluated for its applicability in separating the radioactive nuclides. Results showed that Cyanex301 could easily extract Co and Eu from Ca-rich wastewater without extracting Ca, while Cyanex272 could selectively separate Eu without extracting Co and Ca at pH 2-3. The extracted Co and Eu from the wastewater could be considered as non-radioactive industrial waste after being treated, which can be economically and easily handled. Additionally, the separated Co and Eu may be reused for research and industrial applications through waste valorization.