Development of a purification technology for treatment of medium- and low-activity radioactive waste of radiochemical production from Co-60 and Cs-137

Gleb Apalkov,Andrey Zhabin,Sergey Smirnov,Alexander Dyachenko

doi:10.1051/matecconf/20168501021

Abstract

The technological flowchart of purification of medium- and low-activity waste from Co-60 and Cs-137 is developed and introduced. The developed purification scheme has been successfully tested using genuine medium- and low-level liquid radioactive waste of radiochemical production containing complexing and colloid forming components complexons, surfactants. The optimal conditions of the presented method of purification ensure reduction of the residual specific activity of 60Co and 137Cs radionuclides in the solution to less than 0,9 Bq per litre.

Highlights

A critical task for providing radiation safety at radiochemical plants is solution to the problem of treatment and reprocessing of liquid radioactive waste (LRW), generated from the operation of power installations, various technological procedures with solutions containing radionuclides, during decontamination of equipment, etc
The developed method has significant advantages over the known methods of purification of LRW generated at radiochemical plants and nuclear power stations due to a more complete oxidation of organic components of LRW in the dynamic mode of the column operation during considerably less time available for contact (50÷130 sec) combined with high efficiency of the column (3÷15 column volume/per hour), at lower temperature of the process (47,5÷80°ɋ)
Process variables do not depend on turbidity and salt composition of the solution and allow a wide range of the flow rate and temperature setting without sacrificing oxidation efficiency of organic components of LRW, which enables treatment of ɫloudy solutions without preliminary clarification

Summary

Introduction

A critical task for providing radiation safety at radiochemical plants is solution to the problem of treatment and reprocessing of liquid radioactive waste (LRW), generated from the operation of power installations, various technological procedures with solutions containing radionuclides, during decontamination of equipment, etc. In case of considerable volumes of LRW decontamination factor (index), and residue levels of radionuclides in solutions after their treatment are critical, that enables reuse of water resources without boiling and utilization of stillage residue. The main radionuclides which LRW are purified from are 137Cs, 60Co. Ion-selective methods of purification from 60Co used in the technology suggests preliminary acid treatment of solutions aimed at destroying complexing agents and subsequent stages of radionuclide release, e.g., use of inorganic sorbent agents and cation exchange resins used for desalinization. The decontamination factor for 60Co is usually less than 102, which does not allow reducing general activity of solutions after treatment of less than10÷50 Bq/L

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Conclusion