Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Asahi, Yoshimitsu; Fukuda, Shigeki; Shiramizu, Daiki; Miyata, Koshi; Tone, Masaya; Katsuoka, Nanako; Maeda, Yuta; Aoyama, Yusuke; Niitsuma, Koichi; Kobayashi, Hidekazu; et al.
JAEA-Technology 2024-024, 271 Pages, 2025/03
JAEA-Technology-2024-024.pdf:33.98MB
JAEA-Technology-2024-024-hyperlink.zip:31.96MB
A glass melter for the vitrification process of highly active liquid waste in the Tokai Reprocessing Plant, TVF's 3rd melter, was built, and the glass of 18 vitrified waste canisters in weight was melted and poured through a cold test operation. The molten glass surface was covered by a cold cap from feeding fiberglass cartridges saturated with non-radioactive simulant liquid waste as raw material, whose components are equivalent to actual waste. Differences in inherent characteristics of the thermal behavior between the 2nd and the 3rd melter due to the difference in design were considered to establish the procedure to control the new melter. The melter's condition was stabilized at a higher glass temperature and the cooling of 1 kW less in each of the two main electrodes, compared to the 2nd one. Under 39 kW joule heating of the main electrodes with 26 Nm3/h coolant flow rate, it showed the capability to finish heating the bottom furnace in 5 hours before pouring, 2 hours shorter than the 2nd melter. Measurements of the temperature distributions in molten glass and casing surface yielded data that is efficient for developing a simulation model. After Platinum Group Elements (PGE) concentration saturates in the molten glass, feeding raw material and discharging glass were suspended to examine a holding state, indicating PGE settling could retard. During the holding test, observation of the melting process of the cold cap declared that the surface was covered by a thin layer with almost non-fluidity. It will be a reason for choosing the no-slip condition of a fluid calculation, even in the hot-top condition. The investigation of PGE discharging behavior by analyzing the elemental composition of poured glass showed the accumulated PGE amount in the 3rd melter is small compared to the 2nd melter. Inspection of the melter inside after draining out concluded that there were neither significant residual glass nor refractory fragments.
-P adsorbent for MA(III) recoveryKofuji, Hirohide; Watanabe, So; Takeuchi, Masayuki; Suzuki, Hideya; Matsumura, Tatsuro; Shiwaku, Hideaki; Yaita, Tsuyoshi
Progress in Nuclear Science and Technology (Internet), 5, p.61 - 65, 2018/11
Fukui, Toshiki*; Maki, Takashi*; Miura, Nobuyuki; Tsukada, Takeshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.169 - 173, 2016/12
The basic research programs for the next generation vitrification technology, which are commissioned project from Ministry of Economy, Trade and Industry of Japan, have been implemented from 2014 until 2018 for developing the advanced vitrification technology of low level wastes and high level liquid wastes.
Kofuji, Hirohide; Watanabe, So; Goto, Ichiro; Oriuchi, Akio; Takeuchi, Masayuki; Kobayashi, Hidekazu; Sasage, Kenichi
no journal, ,
Vitrification procedure for the extraction chromatography using porous silica covered with extractant were examined. In this method, it was expected that minor actinide (MA) were separated from high level radioactive liquid waste using extractant CMPO and/or HDEHP. In this study, vitrified adsorbent with simulated high level liquid waste were prepared and evaluated from some viewpoints of high level waste form properties. As the results, selected adsorbent were generally well vitrified and had enough chemical durability.
Kofuji, Hirohide; Watanabe, So; Goto, Ichiro; Oriuchi, Akio; Takeuchi, Masayuki; Kobayashi, Hidekazu; Sasage, Kenichi
no journal, ,
Vitrification procedure for extraction chromatography using porous silica particles covered with extractant was investigated. In this method, minor actinides (MAs) were separated from high-level radioactive liquid waste by extractant CMPO and/or HDEHP. In this study, thermal degradation behavior and vitrification properties were evaluated from the viewpoints of high-level wasteform properties using porous silica adsorbent impregnated with extractant CMPO and HDEHP. As the results of various experiments, suitable vitrification procedure for MA/RE adsorbents was clarified and selected adsorbent was generally well-vitrified and had enough chemical durability.
Kobayashi, Hidekazu; Kodaka, Akira; Iwabuchi, Hiroki
no journal, ,
In JAEA's Tokai Vitrification Facility (TVF) at Tokai Reprocessing Plant (TRP) site, high level liquid waste (HLLW) generated from reprocessing of spent fuels is vitrified with a liquid-fed joule-heated ceramic melter (LFCM). As noble metals (NMs) in HLLW aren't soluble to the glass, and have low resistivity and higher density, they deposit on bottom of melter and form electrical path and thus disturb melter operation. The first and second TVF melter have square pyramidal shaped bottom and issue that NMs on the bottom are difficult to drain out and have to be removed periodically. To solve this issue, we are developing the third melter with conical shaped bottom. The effect of changing the bottom structure was confirmed by thermo-fluid analysis code. Structural optimization of strainer in the upper part of drain nozzle was carried out by visualization experiment. In this meeting, activity of third melter development including past melter structure will be introduced.
Ayame, Yasuo; Iwabuchi, Hiroki; Omori, Eiichi; Miura, Nobuyuki
no journal, ,
Tokai Reprocessing Plant (TRP) is preparing for decommissioning and dismantling, and it takes decades for completion. As about 360 m
of HLLW in TRP has risk of evaporation and hydrogen explosion, it must be controlled safely by keeping forced cooling and hydrogen exhausting. So, it was decided to vitrify in Tokai Vitrification Facility (TVF) by 2028 to reduce the risk. TVF was constructed in 1992 and vitrified 306 canisters until now. Full remote maintenance system is adopted for vitrification melter and HLLW tank in the cell. As noble metals in HLLW accumulate at bottom of melter, the melter must be emptied periodically and the noble metals must be removed with mechanical device. For the success of the vitrification, it is necessary to maintain the equipment by organized maintenance plan considering its aging, to expand the capacity to store canisters and to replace the melter within its design life. In this meeting, vitrification plan at Tokai site will be introduced.
Yoshioka, Masahiro*; Fukui, Toshiki*; Miura, Nobuyuki; Tsukada, Takeshi*
no journal, ,
The basic research programs for the next generation vitrification technology, which are commissioned project from Ministry of Economy, Trade and Industry of Japan to IHI Corporation (IHI), Japan Nuclear Fuel Limited (JNFL), Japan Atomic Energy Agency (JAEA) and Central Research Institute of Electric Power Industry (CRIEPI), have been implemented from 2014 for developing the advanced vitrification technology of low level wastes and high level liquid wastes (HLLW). In these programs, the developmental works such as the high waste loading glass, the alternate glasses of current borosilicate glasses including glass-ceramics and the minor actinide adsorbent glasses have been entrusted with the above organizations.
Yamauchi, Sho; Tokoro, Takeshi; Kuboki, Michikatsu; 9 of others*
no journal, ,
no abstracts in English
Ishio, Takahiro*; Kanehira, Norio*; Hoshino, Takeshi*; Fukui, Toshiki*; Iwabuchi, Hiroki; Tsukada, Takeshi*
no journal, ,
In Japan, the High Level radioactive Liquid Waste (HLLW) generated along with the nuclear fuel cycle is to be vitrified, and its vitrification technology has been made practicable. And, various kinds of Low Level radioactive Liquid Waste (LLW) generated from reprocessing plant and nuclear power plants in Japan have been primarily treated by various methods such as incineration, compaction, cement solidification, however, vitrification method have not been introduced. On the other hand, there is a potential generation of LLW which has relatively high radioactivity level in case of conducting the decommissioning of reprocessing plant and nuclear power plants. Therefore, various kinds of the solidification and the volume reduction technologies have been developed in order to ensure the stable forms with smaller volumes for the LLW disposal. Furthermore, if the foundation for LLW vitrification technology is developed, it can be reflected in the advancement of vitrification technology of HLLW. Therefore, the Ministry of Economy, Trade and Industry launched the project "Basic Research Programs of Vitrification Technology for Waste Volume Reduction" during FY 2014 - 2018. IHI Corporation (IHI), Japan Nuclear Fuel Limited (JNFL), Japan Atomic Energy Agency (JAEA) and Central Research Institute of Electric Power Industry (CRIEPI) have commissioned this project. The development goals for this project are as follows. (1) To develop LLW generated at nuclear power plants and reprocessing plant, etc., to reinforce the foundation of vitrification technology for high volume reduction and more stable waste. (2) To study also advanced improvement of vitrification of HLLW that is practically used in Japan, by reflecting the findings obtained from LLW infrastructures. In this presentation we will report on our past achievements and future plans in this project.
