[2N04-06] Decommissioning of Reprocessing Plant, and Transport Package

10:20 AM - 10:35 AM JST(1:20 AM - 1:35 AM UTC)

[2N04] Flush-out for Tokai Reprocessing Plant decommissioning(3) Disposal of the low-concentration Pu solution

*Futoshi Yanagibashi¹, Shinichi Nagaoka¹, Hiroyasu Isobe¹, Takeshi Yasuda¹, Yuji Yada¹, Shohei Suzuki¹, Hayate Tokoro¹, Shota Kusaka¹, Keita Shoji¹, Hirotaka Samoto¹ (1. JAEA)

Keywords:

Tokai Reprocessing Plant,decommissioning,Flush-out,Pu solution

Tokai Reprocessing Plant (TRP) retained nuclear materials, such as low-concentration Pu solution due to TRP’s shift to decommissioning in anticipation of resuming reprocessing. Pu solution required disposal as Flush-out before decontamination of equipment.Considering the operational range, the processing period, and the utilization after processing, Pu solution was transferred to high-active liquid waste tanks without evaporation or MOX conversion.During transferring, there was a critical risk due to Pu polymer formation caused by increasing in liquid temperature and decreasing in acid concentration. Based on past experience, U solution was mixed before transfer, and the acid concentration of the receiving tanks was adjusted. These measures prevented Pu polymer formation, ensured critical safety, and completed the disposal of low-concentration Pu solution.