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Aoya, Juri; Mori, Amami; Sato, Hinata; Kono, Soma; Morokado, Shiori; Horigome, Kazushi; Goto, Yuichi; Yamamoto, Masahiko; Taguchi, Shigeo
JAEA-Technology 2023-008, 34 Pages, 2023/06
JAEA-Technology-2023-008.pdf:1.92MB
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.
Ishibashi, Atsushi; Saegusa, Yu; Aoya, Juri; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko
Nihon Hozen Gakkai Dai-18-Kai Gakujutsu Koenkai Yoshishu, p.241 - 244, 2022/07
no abstracts in English
Aoya, Juri; Miyata, Katsuhiko*; Terakado, Akihito*; Otsuzumi, Yoji*; Kurosawa, Daiki*; Sunaba, Takanobu*; Oyama, Yuto*; Inada, Satoshi
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.507 - 512, 2021/07
The high level radioactive liquid waste is analyzed for the vitrification process control and the vitrified waste quality in the hot cell of Tokai Vitrification Facility, Tokai Reprocessing Plant. There are 8 Master-slave manipulators, 7 lighting equipment, an electronic balance, and an inductively coupled plasma-optical emission spectrometer used for remote operation, securing visibility, total oxide analysis, and elemental analysis in the analytical hot cell. These equipment and analytical apparatus must be secured with the integrity all the time because the vitrification process cannot be proceeded without analysis of the high level radioactive liquid waste. We constructed the self-remote-maintenance technologies of these equipment and analytical apparatus which reduce the risks of radioactive contamination, radiation exposure, and injury of an operator and also were optimized with respect to a labor, time, and cost, based on the operation of approximately 20 years.
Aoya, Juri; Kono, Soma; Yamamoto, Masahiko; Inada, Satoshi; Kuno, Takehiko
no journal, ,
Vitrification of high active liquid waste (HALW) is a top priority toward the decommissioning of Tokai Reprocessing Plant. Concentration of Sodium (Na) in HALW is required to be analyzed accurately and quickly for the vitrification process control, because it affects viscosity of molten glass and element leaching rate from the vitrified waste. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is modified for remote operation by manipulator in the hot cell, is used for determination of Na in HALW. However, the trouble of the ICP-OES generally requires long recovery time and causes possibility of the vitrification process delay. Therefore, for alternative determination method to prevent the vitrification process delay, Na determination method in HALW using Na-ion selective electrode, which measures electromotive force generated in accordance with ion concentration in solution sample is developed. In this study, influences by hydrogen ion (H
) and the other coexistent elements on analytical performance, and measurement results of Na in HALW by the ion selective electrode are reported.
Sugaya, Atsushi; Meguro, Yoshihiro; Kitagawa, Osamu; Aoya, Juri
no journal, ,
I will offer a presentation about update on decommissioning and radioactive waste management in Monju, Fugen and TRP at the JAEA and situation of co-operation with NDA in UK. I also give
Aoya, Juri; McCombs, H.*; Sugaya, Atsushi; Taguchi, Shigeo; Kitagawa, Osamu; Meguro, Yoshihiro; Crowther, M.*
no journal, ,
NDA and JAEA have a collaboration agreement to promote information sharing and best practice in radioactive waste management and decommissioning since 2008. NDA and JAEA have different challenges and approaches to ongoing projects. Both organizations have mutual interest in their respective technologies and experiences since cooperation would be mutual benefit to complete decommissioning and radioactive waste management safely and effectively. Within the collaboration agreement, the presenters visited NDA and JAEA sites to obtain a greater understanding and opportunities to discussion on decommissioning projects. This project aims to identify the potential collaboration areas and challenges, which could be supported by the technologies from another organization. The recommendations for future collaboration opportunities are reported with the current progress towards decommissioning across the NDA and JAEA estates.