METHOD FOR LIQUID RADIOACTIVE WASTES PROCESS

摘要

This method finds application in reprocessing of liquid (radioactive waste) from boron-moderated pressurized-water nuclear power plants. This process results in usable non-radioactive boric acid, and reduces the amount of non-radioactive material required for pH correction relative to that required in existing processes. According to this method, acidic and basic liquid radioactive materials are collected separately, and liquid radwaste with pH higher than 4.5 and pH higher than 8.5 (having sodium metaborate concentrations less than or equal to 200 g/L) are concentrated separately, in such a way as to maintain the pH of the mixture at 8.2-9.7. Borax crystallization is then performed in a heat exchanger that is in contact with the radioactive concentrate. This is followed by washing and dilution with desalinated water, heating of the resulting solution, filtration, recrystallization, a second rinsing, and ion-exchange filtration.