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Yoshida, Hidekazu*; Yamamoto, Koshi*; Asahara, Yoshihiro*; Maruyama, Ippei*; Karukaya, Koichi*; Saito, Akane*; Matsui, Hiroya; Mochizuki, Akihito; Jo, Mayumi*; Katsuta, Nagayoshi*; et al.
Communications Engineering (Internet), 3, p.67_1 - 67_10, 2024/05
A capability to permanently seal fluid flow-paths through bedrock, like boreholes or underground tunnels, is needed to ensure the long-term safety and effectiveness of many underground activities e.g. CO
storage, hydrocarbon field abandonment, and nuclear waste disposal. Commonly used cementitious seals may not be sufficiently durable due to chemical and physical degradation. Learning from natural calcite (CaCO
) concretion formation, a more durable sealing method was developed using a "concretion-forming solvent". The method was tested by sealing flow-paths next to a tunnel in an underground research laboratory at 350 meters depth. The flow-paths initially sealed rapidly, then resealed after disturbance by earthquakes (M5.4). The treated rock recovered its very low natural permeability, demonstrating permanent sealing that is robust.
Yamamoto, Kazami; Moriya, Katsuhiro; Okita, Hidefumi; Yamada, Ippei; Chimura, Motoki; Saha, P. K.; Shobuda, Yoshihiro; Tamura, Fumihiko; Yamamoto, Masanobu; Morishita, Takatoshi; et al.
Journal of Neutron Research, 26(2-3), p.59 - 67, 2024/01
The linac and 3 GeV rapid cycling synchrotron at the Japan Proton Accelerator Research Complex was designed to provide 1-MW proton beams to the following facilities. Thanks to the improvement works of the accelerator system, we successfully accelerate 1-MW beam with quite small beam loss. Currently, the beam power of RCS is limited by the lack of anode current in the RF cavity system rather than the beam loss. Recently we developed a new acceleration cavity that can accelerate a beam with less anode current. This new cavity enables us not only to reduce requirement of the anode power supply but also to accelerate more than 1-MW beam. We have started to consider the way to achieve beyond 1-MW beam acceleration. So far, it is expected that up to 1.5-MW beam can be accelerated after replacement of the RF cavity. We have also been continuing study to achieve up to 2 MW beam in J-PARC RCS.
evaluation tests in an Underground Research Laboratory, Horonobe, JapanYoshida, Hidekazu*; Yamamoto, Koshi*; Asahara, Yoshihiro*; Maruyama, Ippei*; Karukaya, Koichi*; Saito, Akane*; Matsui, Hiroya; Mochizuki, Akihito; Katsuta, Nagayoshi*; Metcalfe, R.*
Powering the Energy Transition through Subsurface Collaboration; Proceedings of the 1st Energy Geoscience Conference (Energy Geoscience Conference Series, 1), 20 Pages, 2024/00
A capability to permanently seal fluid flow-paths in bedrock, such as natural faults/fractures, and damaged zones around boreholes/excavations, is needed to ensure the long-term safety and effectiveness of many underground activities. Cementitious materials are commonly used as seals, however these materials unavoidably undergo physical and chemical degradation, therefore potentially decreasing seal durability. In order to solve these problems, a more durable sealing method using concretion-forming resin has been developed by learning from natural calcite (CaCO) concretion formation. The sealing capability of resin was tested by experiments on bedrock flow-paths in an underground research laboratory (URL), Hokkaido, Japan. The results showed a decrease the permeability rapidly down to 1/1,000 of the initial permeability due to calcite precipitation over a period of one year. During the experiment inland earthquakes occurred with foci below the URL (depths 2-7 km and maximum magnitude 5.4). Due to the earthquakes the hydraulic conductivities of the flow-paths sealed initially by concretion-forming resin increased. However, these flow-paths subsequently resealed rapidly, and within a few months recovered the same hydraulic conductivities as before the earthquakes. This new technique for rapidly producing long-lasting seals against fluid flow through rocks will be applicable to many kinds of underground activities.
Nagayama, Shota; Harada, Hiroyuki; Shimogawa, Tetsushi*; Sato, Atsushi*; Yamada, Ippei; Chimura, Motoki; Kojima, Kunihiro; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.526 - 530, 2023/11
We have been developing "Non-destructive electrostatic septum" for a slow extraction. This septum has multiple electrodes placed around the region without the beam hitting and separate the beam by its electric field. To evaluate its electric field, we have built a prototype septum and a test machine, which consists of an electron gun and monitors. This test machine can measure the electric field indirectly by using a narrow electron beam. The experiment results of prototype septum is good agreement with the calculation one. However, this electric field distribution is not enough to separate the beam. A step function-like electric field distribution is ideal for the beam separation with minimal negative effect on the beam. We have studied to improve the electrode configuration to match the beam shape. In this paper, we present the result of the electric field measurements and the septum improvement. Additionally, we describe the future plan of this development.
Yamamoto, Kazami; Moriya, Katsuhiro; Okita, Hidefumi; Yamada, Ippei; Chimura, Motoki; Saha, P. K.; Shobuda, Yoshihiro; Tamura, Fumihiko; Yamamoto, Masanobu; Morishita, Takatoshi; et al.
Proceedings of 68th ICFA Advanced Beam Dynamics Workshop on High Intensity and High Brightness Hadron Beams (HB2023) (Internet), p.270 - 273, 2023/10
The 3-GeV rapid-cycling synchrotron at the Japan Pro-ton Accelerator Research Complex was designed to provide 1-MW proton beams to the following facilities. Thanks to the improvement works of the accelerator system, we successfully accelerate 1-MW beam with quite small beam loss. Currently, the beam power of RCS is limited by the lack of anode current in the RF cavity system rather than the beam loss. Recently we developed a new acceleration cavity that can accelerate a beam with less anode current. This new cavity enables us not only to reduce requirement of the anode power supply but also to accelerate more than 1-MW beam. We have started to consider the way to achieve beyond 1-MW beam acceleration. So far, it is expected that up to 1.5-MW beam can be accelerated after replacement of the RF cavity. We have also continued study to achieve more than 2 MW beam in J-PARC RCS.
Yamamoto, Kazami; Yamada, Ippei
Proceedings of 14th International Particle Accelerator Conference (IPAC 23) (Internet), p.2339 - 2341, 2023/05
The 3 GeV rapid cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) provides more than 800 kW beams to the Material and Life Science Facility (MLF) and Main Ring (MR). We have been continuing a beam study to achieve 1-MW, design power operation. In addition, we have also improved and maintained the accelerator components to establish a stable operation. This paper reports the status of the J-PARC RCS in recent years. In summary, the RCS can be operated quite stable, but we were not able to keep 1-MW beam in the summer condition.
Nagayama, Shota; Harada, Hiroyuki; Shimogawa, Tetsushi*; Yamada, Ippei; Chimura, Motoki; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.503 - 507, 2023/01
Synchrotron accelerators realize physics experiments and radiation cancer treatment using the slow extraction technique, in which beams are stored in the ring and gradually delivered. We have devised and are currently developing a "non-destructive electrostatic septum" based on a new method, which in principle cannot be solved by conventional methods and is a cause of equipment failure and output limitation. It is ideal to generate a force distribution similar to a staircase function with discontinuous gaps at the boundary. In this presentation, we will show the calculation method for optimizing the electrode and wire configuration to generate a Lorentz force with a distribution similar to a staircase function in vacuum, and the calculation results of the beam breakup due to the generated Lorentz force. The compact proof-of-principle machine developed for the ongoing demonstration of this method will also be introduced.
addition on water durability of FeO-FeO-PO
glassesKitamura, Naoto*; Nomura, Akira*; Saito, Akira*; Kobayashi, Hidekazu; Amamoto, Ippei; Takebe, Hiromichi*
Journal of the Ceramic Society of Japan, 126(11), p.948 - 951, 2018/11
Times Cited Count：6 Percentile：15.65(Materials Science, Ceramics)We studied compositional dependence of water durability of Zr(IV) containing FeO-FeO-PO glasses systems, which can apply to immobilize nuclear waste of Zr isotope. Stabilized film with interference fringe on the surface improves better water durability after immersion tests for BaO and ZrO coexisting glasses without fracture. On the other hand, microcrystalline ZrPO
was detected in the glass matrix when more than 1 mol% of ZrO incorporated. The effect of impregnated ZrPO crystal on the structure was discussed based on the phosphate structure analyzed by Raman spectra. Formation of Q
and Q
units, which contribute to water durability in the glass, are due to preferential precipitation of ZrPO crystal.
Amamoto, Ippei
Journal of the Society of Inorganic Materials, Japan, 24(391), p.393 - 401, 2017/11
Glass is a non-crystalline solid, as such, it is relatively easy to change its composition to control its characteristics. The borosilicate glass, which is produced by the addition of boron oxide into sodium-lime glass, possesses excellent heat-resistant properties and mechanical strength. It has a wide variety of uses. The borosilicate glass is applied as the vitrified medium for radioactive wastes to immobilize and stabilize them for long term. The glass form which is loaded with high-level radioactive waste is called the vitrified waste. This paper classified the radioactive waste and describes treatment and production methods of vitrified waste, its characteristics, disposal method and also introduces alternative vitrified medium.
Amamoto, Ippei; Kobayashi, Hidekazu; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Fukayama, Daigen*; Nagano, Yuichi*; Jantzen, T.*; Hack, K.*
Journal of Nuclear Science and Technology, 53(10), p.1467 - 1475, 2016/10
Times Cited Count：5 Percentile：40.14(Nuclear Science & Technology)The iron phosphate glass (IPG) medium is known to be a high-efficiency glass medium, therefore we try to evaluate its applicability to immobilize sludge bearing radioactive nuclides arising from treatment of contaminated water at the stricken Fukushima Daiichi Nuclear Power Plant. For this study, many physical and chemical properties of target materials are necessary to evaluate the behaviours of IPG medium and its waste forms. Inevitably, it will entail the need for many and varied types of experiments to be carried out under high temperature. It is therefore rational to apply appropriate theoretical analysis first so as to reduce the number of experimental run. For this reason, some necessary thermodynamic values for theoretical analysis were estimated by CALPHAD approach followed by making up the calculated phase diagrams. By comparison with experimental results, they were found to be reliable for evaluating the behaviours of IPG medium and its waste forms.
Tsuzuki, Tatsuya*; Mitamura, Naoki*; Amamoto, Ippei
Shakai, Kankyo Hokokusho 2014 (Internet), p.6 - 7, 2014/10
no abstracts in English
Amamoto, Ippei
Nihon Gakujutsu Shinkokai Gokin Jotaizu Dai-172 Iinkai Kenkyu Hokokusho Vol.14, No.1, p.1 - 11, 2014/05
no abstracts in English
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
Tekisuto "Kakunenryo Saikuru" (Internet), 10 Pages, 2012/12
no abstracts in English
Tsuzuki, Tatsuya*; Mitamura, Naoki*; Amamoto, Ippei
Mirai Zairyo, 12(10), p.43 - 47, 2012/10
no abstracts in English
Amamoto, Ippei
Radioactive Waste; Sources, Types and Management, p.97 - 126, 2011/11
In this paper, the author has briefly introduced the development of pyroprocessing, highlighting the spent electrolyte treatment from the viewpoint of economical and environmental load reduction. The zeolite sorption method developed in USA is currently most progressive technique. There are other methods which use phosphates to treat the spent electrolyte, among them three are presented here, i.e., the phosphates precipitation method developed by RIAR, the GRSS method using SAP by KAERI, and the phosphate conversion method by JAEA. In the phosphate conversion method, the iron phosphate glass (IPG), which possesses unique properties, is employed for FP separation and FP immobilization. From preliminary experiments, it found that the IPG could separate insoluble FP in the spent electrolyte when used as a filtration medium. In addition, when used as a sorbent, it could remove the soluble FP. The IPG is regarded as a potential effective material to treat FP as well as the glass medium.
Amamoto, Ippei
Journal of MMIJ, 127(1), p.1 - 7, 2011/01
The pyroprocess as a non-aqueous reprocessing, is oriented as a complementary concept for the Fact Project. The pyroprocess possesses some inherent problems that have yet to be solved. The purification and recycling of the spent electrolyte as a regenerated medium by removing its fission products (FP) must be further investigated to reduce the volume of high-level radioactive waste (HLW). Some FP elements dissolved in the medium are apt to remain in the spent electrolyte after recovering actinoid elements. To remove such FP, the zeolite sorption is applied as it is considered the most suitable method, but its concept should be modified in order to reduce the generating waste volume. As one of the solutions, the electrolyte recycle process by phosphates is being developed. In this paper, the author has discussed the pyroprocess development, highlighting the spent electrolyte treatment from the viewpoint of economical and environmental load reduction.
Mitamura, Naoki*; Tsuzuki, Tatsuya*; Amamoto, Ippei
Nihon Genshiryoku Gakkai Wabun Rombunshi, 9(4), p.396 - 404, 2010/12
Iron phosphate glass could be used to immobilize the high-level radioactive waste (HLW) and has the possibility to function as a Cs sorpant. However, the glass must endure high temperature from about 350
C, the melting point of LiCl-KCl electrolyte, to 600C, the operational maximum temperature. In this study, we have successfully developed the iron phosphate glasses functioning as Cs sorpant, possessing heat resistance, etc.. To prevent the glass softening at temperature around 600C, alkali metal oxides, alkaline-earth metal oxides, alumina and/or titania were added into the FeO-PO glass. Through soak experiments of the glasses in molten salt(
LiCl-KCl)containing CsCl, it was found that those glasses immobilize Cs by reacting with CsCl and formed crystal phase of CsFeCl and/or CsFeCl. This Cs sorption function is peculiar to the developed iron phosphate glasses.
Amamoto, Ippei; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Takasaki, Yasushi*; Shibayama, Atsushi*; Yano, Tetsuji*; Nakada, Masami; Okamoto, Yoshihiro
Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.503 - 508, 2010/10
The main objective of this development is to recycle the purified eutectic medium of the pyroreprocessing, delaying its disposal for as long as possible. We have introduced the simple filtration method to remove the rare earth element (REE) particles which were formed due to the conversion of REE chlorides to phosphates. Here, the iron phosphate glass is used as a filtration medium for the removal of FP particles. However, some soluble FP such as compounds of alkali-metals, alkaline-earth metals, etc. still remain in the eutectic medium. This time around, on an experimental basis, the iron phosphate glass has been used as a sorbent instead, to remove the soluble FP. We have obtained some positive results and have intention to incorporate it into the spent electrolyte recycle process as a part of the FP separation and immobilization system.
