Characterization of precipitates formed in simulated high-level liquid wastes

Murao, Ayako*; Mimura, Hitoshi*; Kirishima, Akira*; Kondo, Yoshikazu*; Nomura, Kazunori  ; Washiya, Tadahiro 

The characterization of the precipitates formed in the simulated high-level liquid waste (SHLLW) has been studied in order to investigate the formation behavior of sludge in reprocessing process. Zirconium molybdate hydrate (ZMH) is known as the main component of the precipitates formed in the reprocessing process, and the precipitation of ZMH is responsible for the troubles in the vitrification process in nuclear reprocessing plants. Therefore, it is very important to clarify the formation mechanism of ZMH and to develop the effective treatment process. The SHLLW in the reaction vessel equipped reflux condenser was heated at 95 C for 4 h on the hot plate and stirred at 700 rpm. As a result, the concentration of Zr, Mo and Te decreased with increasing the heating time. The formation rate of precipitation increased with increasing the initial metal concentration, indicating the enhancement of the crystal growth.