Development of solidification techniques with minimized water content for safe storage and disposal of secondary radioactive aqueous wastes in Fukushima

Meguro, Yoshihiro  

From contaminated water treatment systems at Fukushima Daiichi Nuclear Power Station, various radioactive wastes have been generated and stored. Especially, concentrated waste liquid, iron hydroxide slurry and carbonate slurry contain high concentration of strontium-90 and a large amount of water and sea water components. Therefore, when these wastes are stored for a long period, the risk of leakage of radioactive waste due to corrosion of storage containers and burning of hydrogen gas generated by radiolysis increases. In this research, we are developing technology to solidify these wastes using phosphate solidification materials. We are trying suppressing the generation of hydrogen gas by performing heat dehydration at the time of curing of the solidified material and to fix Sr and seawater component by making poorly water-soluble stable compounds.