Method for treating radioactive waste solution and device for treating same

Abstract

Disclosed is a method for treating a radioactive waste solution containing a sodium salt which comprises: a waste solution-reducing step for partially reducing sodium nitrate contained in the radioactive waste solution to thereby convert the radioactive waste solution into a reduced solution containing at least one compound selected from sodium hydroxide, sodium hydrogen carbonate and sodium carbonate; and an electrodialysis step for supplying the reduced solution to an anode chamber in an electrolytic tank, in which an anode and a cathode are provided on either side of a permeable membrane that selectively allows the passage of sodium ion, and electrodialyzing the reduced solution. The method for treating a radioactive waste solution is characterized in that: in the electrodialysis step, sodium ion having passed through the permeable membrane is separated and recovered as sodium hydroxide in the cathode chamber; a radioactive substance remaining in the anode chamber is separated as a concentrated radioactive substance solution; the thus separated sodium hydroxide and concentrated radioactive substance solution are each recovered; and the formation speed of at least one compound selected from sodium hydroxide, sodium hydrogen carbonate and sodium carbonate in the waste solution-reducing step is equalized to the recovery speed of sodium ion in the electrodialysis step. Also disclosed is a device for treating a radioactive waste solution.

Description

technical field [0001] The present invention relates to a treatment method and device for radioactive waste liquid. More specifically, it relates to a method for electrodialysis of radioactive waste liquid mainly composed of sodium nitrate discharged from nuclear facilities, especially reprocessing facilities. A treatment method and a treatment device for radioactive waste liquid that selectively removes sodium to separate and recover radioactive substances. [0002] This application is based on and claims the priority of Japanese Patent Application No. 2009-093878 for which it applied to Japan on April 8, 2009, and uses the content here. Background technique [0003] From nuclear facilities, especially reprocessing facilities for spent nuclear fuel, produce mainly large quantities of sodium nitrate (NaNO 3 ) as radioactive waste liquid of inorganic salts. The development of a separation and removal technology for separating sodium from sodium nitrate in this waste liquid ...

AI Technical Summary

Problems solved by technology

Due to the addition of a large amount of reagents, this method not only increases the amount of waste liquid, but also has a limit of about 100 for the decontamination factor (DF), which indicates the extent to which radioactive nuclei are removed, for specific nuclei. The removal efficiency of radioactive nuclei in the liquid is low

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