Characterization of carbonate slurry waste from multi-radionuclide removal system in Fukushima Daiichi Nuclear Power Station

Hinai, Hiroshi; Shibata, Atsuhiro  ; Nomura, Kazunori  

Multi-Radionuclide Removal System (MRRS) has been operating to decontaminate the contaminated water in Fukushima Daiichi Nuclear Power Station. Although this system removes most of the radioactive materials, significant amount of secondary radioactive wastes (slurry, spent adsorbent) were generated subsequently to the treatment. In particularly, because of the high radioactivity and the abundance of generation amount, the carbonate slurry waste is required to characterize preferentially. It is necessary to various properties investigation for selecting suitable treatment and disposal methods. Therefore, the carbonate slurry samples taken from the MRRS were transferred from Fukushima Daiichi Nuclear Power Station to the Chemical Processing Facility (CPF) in Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA), and was analyzed for radioactivity, amount of element composition and particle size distribution. The radioactive analysis showed that the main nuclides of carbonate slurry were Sr-90/Y-90. In addition, small amount of alpha-ray emitting nuclides was determined. As the result of elemental analysis, it is estimated that most of slurry are composed by CaCO and Mg(OH). The median particle diameter of carbonate slurry samples was found to be several micrometre.