Analysis work report on removal of spent fuel sheared powder for decommissioning of main plant

Aoya, Juri; Mori, Amami ; Sato, Hinata; Kono, Soma  ; Morokado, Shiori; Horigome, Kazushi ; Goto, Yuichi ; Yamamoto, Masahiko   ; Taguchi, Shigeo 

Flush-out, by which nuclear materials in the Tokai Reprocessing Plant process are recovered, has been started in June 2022 as the first step of decommissioning. Flush-out consists of removal of spent fuel sheared powder, plutonium solution, uranium solution, and the other nuclear materials. Removal of spent fuel sheared powder has been completed in September 2022. During removal of spent fuel sheared powder, uranium concentration, plutonium concentration, acid concentration, radioactivity concentration, and solution density have been analyzed for process control. For nuclear material accountancy, uranium concentration, plutonium concentration, isotope ratio, and solution density have been analyzed. Analysis work including sample pretreatment before transportation to IAEA analytical facility for safeguards, and the other operations related to Flush-out such as calibration of analytical instruments, education, and training of operators are reported.