Purification of nuclear power plant decontamination solutions by preparative scale reactive adsorption

During alkaline, oxidative decontamination of nuclear power plant equipment a radioactive solution is produced. Owing to the storing difficulties of radioactive solutions it is necessary to develop a method for the in situ treatment of radioactive, alkaline, oxidative decontamination solutions, and for the concentration of radioactive components. Reactive adsorption seems to be promising for this purpose. In reactive adsorption the radioactive nuclides are sorbed at 95oC by an activated carbon. Under the circumstances the reduction of Mn(VII) to Mn(VI) becomes significant on the surface of the activated carbon, and MnO2 precipitation occurs in the pores of the adsorbent. Due to the adsorption- ion exchange properties of MnO2 it can uptake the radioactive isotopes. Simultaneously the new precipitating MnO2 layers cover the surface saturated with radioactive isotopes hereby preventing their desorption, and provide fresh adsorption, ion exchange layer. Under inactive conditions the kinetics of MnO2 precipitation was studied in a stirred batch reactor and the sorption of silver was investigated in a chromatographic column. The purification of nuclear power plant decontamination solutions was also carried out. (Author)