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Kogawa, Hiroyuki; Futakawa, Masatoshi; Haga, Katsuhiro; Tsuzuki, Takayuki*; Murai, Tetsuro*
JAEA-Technology 2022-023, 128 Pages, 2022/11
JAEA-Technology-2022-023.pdf:9.0MB
In a mercury target of the J-PARC (Japan Proton Accelerator Research Complex), pulsed proton beams repeatedly bombard the flowing mercury which is confined in a stainless-steel vessel (target vessel). Cavitation damage caused by the propagation of the pressure waves is a factor of the life of the target vessel. As a measure to reduce damages, we developed a bubbler to inject the gas microbubbles into the flowing mercury, which can reduce the pressure waves. To operate the mercury target vessel stably with the 1 MW high-intensity proton beams, further reduction of the damage is required. The bubbler setting position should be closer to the beam window to increase the bubble population, which could enhance the reduction effect on the pressure waves and damage. However, the space at the beam window of the target vessel is restricted. The bubbler design and setting position as well as the vane design for the mercury flowing pattern are optimized by means of a machine learning technique to get more suitable bubble distribution, increasing in bubble population and optimizing bubble size nearby the beam window of the target vessel. The results of CFD analyses performed with 1000 cases were used for machine learning. Since the flow rate of mercury affects the temperature of the target vessel, this was used for the constraint condition. As a result, we found a design of mercury target vessel that can increase the bubble population by ca. 20% higher than the current design.
as the dominant sludge constituent generated from the treatment of water used for cooling the stricken power reactorsAmamoto, Ippei; Kobayashi, Hidekazu; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
Proceedings of 15th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2013) (CD-ROM), 8 Pages, 2013/09
The great amount of water used for cooling the stricken power reactors at Fukushima Dai-ichi has resulted in accumulation of "remaining water". As the remaining water is subsequently contaminated by FPs, etc., it is necessary to decontaminate it in order to reduce the volume of liquid radioactive waste and to reuse it again for cooling the reactors. Various techniques are being applied to remove FP, etc. and to make stable waste forms. One of the methods using the iron phosphate glass as a medium is being developed to stabilize the strontium-bearing sludge whose main component is BaSO. From the results hitherto, the iron phosphate glass is regarded as a potential medium for the target sludge.
Kobayashi, Hidekazu; Amamoto, Ippei; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
Proceedings of 15th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2013) (CD-ROM), 6 Pages, 2013/09
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Tsuzuki, Tatsuya*; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*
Proceedings of 12th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM '09/DECOM '09) (CD-ROM), 9 Pages, 2009/10
This study is carried out to make the pyroprocessing hold a competitive advantage. As one of the measures is to reduce the volume of HLW, the phosphate conversion method is applied for removal of FP from the spent electrolyte in this paper. Though the removing target elements in the electrolyte are alkali metals, alkaline earth metals and lanthanoid elements, only lanthanoid elements and lithium form the insoluble phosphates by reaction with Li
PO. Therefore, as the first step, the precipitation experiment was carried out to observe the behaviours of elements which form the insoluble precipitates. Then the filtration was experimented to remove precipitates in the spent electrolyte using Fe
O-PO
glass system as a filtlation medium which is compatible material with the glassification. The result of separation of precipitates by filtration was effective and attained almost 100
.
Kobayashi, Hidekazu; Amamoto, Ippei; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kobayashi, Hidekazu; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Fukayama, Daigen*; Nagano, Yuichi*; et al.
no journal, ,
no abstracts in English
Amamoto, Ippei; Kobayashi, Hidekazu; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Suzuki, Yoshikazu*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
The great amount of water used for cooling the stricken reactors at Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 had resulted in accumulation of "remaining water" in some buildings. From public announcements, it seems likely the decontamination process of La Hague reprocessing plant would be employed as one of the treatment processes for the remaining water contaminated by FPs such as Cs, Sr, etc.. Based on literature study, Cs would precipitate with ferrocyanide compound as well as Sr with BaSO by applying the above-mentioned process. In this study, BaSO as the simulated sludge was loaded into the iron phosphate glass (IPG) medium under different melting temperature. Based on the results, the performance of IPG containing BaO (decomposed from BaSO) improved with increase loading of BaO up to 48 mol% at lower melting temperature.
Amamoto, Ippei; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Nakamura, Hirotaka*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Kobayashi, Hidekazu
no journal, ,
no abstracts in English
by the IPG mediumAmamoto, Ippei; Kobayashi, Hidekazu; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Tsuzuki, Tatsuya*; Mitamura, Naoki*; Takasaki, Yasushi*; Shibayama, Atsushi*; Yano, Tetsuji*; Terai, Takayuki*
no journal, ,
no abstracts in English
Kobayashi, Hidekazu; Nagai, Takayuki; Okamoto, Yoshihiro; Sasage, Kenichi; Amamoto, Ippei; Takebe, Hiromichi*; Nakamura, Hiroki*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kobayashi, Hidekazu; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Suzuki, Yoshikazu*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
no abstracts in English
Kobayashi, Hidekazu; Amamoto, Ippei; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*
no journal, ,
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Tsuzuki, Tatsuya*; Mitamura, Naoki*; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*
no journal, ,
no abstracts in English
