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Saito, Shigeru; Meigo, Shinichiro; Makimura, Shunsuke*; Hirano, Yukinori*; Tsutsumi, Kazuyoshi*; Maekawa, Fujio
JAEA-Technology 2023-025, 48 Pages, 2024/03
JAEA-Technology-2023-025.pdf:3.11MB
JAEA has been developing Accelerator-Driven Systems (ADS) for research and development of nuclear transmutation using accelerators in order to reduce the volume and hazardousness of high-level radioactive waste generated by nuclear power plants. In order to prepare the material irradiation database necessary for the design of ADS and to study the irradiation effects in Lead-Bismuth Eutectic (LBE) alloys, a proton irradiation facility is under consideration at J-PARC. In this proton irradiation facility, 250 kW proton beams will be injected into the LBE spallation target, and irradiation tests under LBE flow will be performed for candidate structural materials for ADS. Furthermore, semiconductor soft-error tests, medical RI production, and proton beam applications will be performed. Among these, Post Irradiation Examination (PIE) of irradiated samples and RI separation and purification will be carried out in the PIE facility to be constructed near the proton irradiation facility. In this PIE facility, PIE of the equipment and samples irradiated in other facilities in J-PARC will also be performed. This report describes the conceptual study of the PIE facility, including the items to be tested, the test flow, the facilities, the test equipment, etc., and the proposed layout of the facility.
Saito, Shigeru; Yamaguchi, Kazushi*; Yoshimoto, Hidemitsu*; Obayashi, Hironari; Sasa, Toshinobu
JAEA-Technology 2022-032, 51 Pages, 2023/03
JAEA-Technology-2022-032.pdf:4.51MB
In the Accelerator Driven System (ADS) being studied by the Japan Atomic Energy Agency (JAEA) for transmutation of long-lived radioactive waste, lead-bismuth eutectic alloy (LBE) is used as a spallation target and subcritical core coolant. A proton irradiation facility in J-PARC is considered to prepare a material irradiation database for ADS development. The proton irradiation facility is equipped with an LBE loop, which enables material irradiation tests in spallation environment under flowing LBE condition. The slow leakage of LBE is one of critical issue to use LBE safety. The slow leakage is caused by the biting slag and/or other materials at valve seal of drain valve. To solve this problem, JAEA examined the application of freeze-seal valve (FSV), which seal the piping by freezing LBE in specific position. Water-cooled and air-cooled freeze-seal valve test modules were fabricated, installed in the test section of the existing test stand for LBE technology development, and tested to confirm their operation and performance. As a result of the tests, it was confirmed that the water-cooled FSV test module worked well along to the design values. This report describes the outline and details of the test stand for LBE technology and each FSV test module, as well as the results of operation and performance verification tests.
Saito, Shigeru; Suzuki, Kazuhiro; Obata, Hiroki; Dai, Y.*
Nuclear Materials and Energy (Internet), 34, p.101338_1 - 101338_9, 2023/03
Times Cited Count：2 Percentile：53.91(Nuclear Science & Technology)In this study, a post-irradiation examination of pure tungsten (W) and tantalum (Ta) specimens irradiated at the Swiss Spallation-Neutron Source is conducted. W is used as a potential candidate for a solid spallation-target material owing to its favorable properties. However, W also suffers from several disadvantages such as poor corrosion resistance to water coolant and irradiation embrittlement. To improve these properties, cladding technologies using Ta for W alloys have been developed. In the present study, we investigated the irradiation effects on two tungsten materials, poly-crystal W (W-Poly) and single-crystal W (W-Sin), along with pure polycrystalline Ta. The tensile-test results revealed that W-Poly exhibited almost no ductility after irradiation of 10.2-35.0 dpa. W-Sin was irradiated up to 10.2 dpa and demonstrated 6% of total elongation (TE). With regard to Ta, TE decreased based on the increase in irradiation, reaching almost zero at doses of more than 10.3 dpa.
Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Saito, Shigeru; Wan, T.*; Okubo, Nariaki; Kita, Satoshi*; Obayashi, Hironari; Sasa, Toshinobu
JAEA-Technology 2021-034, 94 Pages, 2022/03
JAEA-Technology-2021-034.pdf:5.91MB
Lead-bismuth eutectic alloy (LBE) is a major candidate for a spallation target material and core coolant of an accelerator driven system (ADS) which has been developed in the Japan Atomic Energy Agency (JAEA) to transmute high-level radioactive wastes. A proton irradiation facility to build a material irradiation database for future ADS development is under considering in the J-PARC. To realize both the ADS and the above-mentioned facility, there are many issues on operational safety of LBE to be solved. Especially, corrosion data for the major materials such as T91 (Modified 9Cr-1Mo steel) and SS316L at the temperature range between 400 and 550 
C under the conditions of flowing LBE with a controlled oxygen are not sufficient to design the ADS and the facility. JAEA developed a new large-scale corrosion test loop named "OLLOCHI (Oxygen-controlled LBE LOop for Corrosion tests in HIgh-temperature)" aiming to perform the compatibility tests between the LBE and the steels, as well as to develop the LBE operation technology. OLLOCHI has a function to automatically control the oxygen concentration in LBE. The maximum temperature at the regions of high-temperature and low-temperature of the OLLOCHI are 550 C and 450 C respectively to cover the ADS designed condition. As a result of 2,000 hours operation, it was demonstrated that the OLLOCHI showed the designed performance. In this report, outline of the OLLOCHI, details of the components, results of characteristic tests, and the future experimental plan are described.
Ariyoshi, Gen; Obayashi, Hironari; Saito, Shigeru; Sasa, Toshinobu
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 10 Pages, 2022/03
To clarify the flow characteristics of heavy liquid-metal (HLM) is important to achieve the construction of nuclear transmutation facility that utilizes HLM as a spallation target and coolant. At present, lead-bismuth eutectic (LBE) spallation target plans to be installed in Japan proton accelerator research complex (J-PARC). LBE is also selected as one of the candidate media of a spallation target and a coolant for innovative nuclear systems such as accelerator-driven system (ADS) and LBE-cooled fast reactor, due to its adequate physical/chemical properties. The characteristics of LBE flowing inside the target are usually clarified with computational fluid dynamics analysis since the measurement techniques for the HLM flow are not well established, especially for high temperature region over 450C that is delivered from ADS's criteria. Therefore, the objective of this study is to develop measurement method for flow characteristics in the high temperature LBE. A miniature electro-magnet is introduced to electro-magnetic probe to overcome the limitation caused by a curie temperature of permanent magnet. To evaluate performance of the new probe, experimental apparatus equipping annular rotating vessel were also manufactured. The new probe was applied to high temperature LBE up to 480C. As a result, proportional induced voltage to the rotation speed of LBE were clearly observed, where excitation currents of the miniature electro-magnet were 0.2 A or 1 A. In this paper, configuration and performance of the newly developed electro-magnet probe to the high temperature LBE will be presented.
Suzuki, Masaaki*; Ito, Mari*; Hashidate, Ryuta; Takahashi, Keita; Yada, Hiroki; Takaya, Shigeru
2020 9th International Congress on Advanced Applied Informatics (IIAI-AAI 2020), p.797 - 801, 2021/07
Saito, Shigeru; Wan, T.*; Okubo, Nariaki; Obayashi, Hironari; Watanabe, Nao; Ohdaira, Naoya*; Kinoshita, Hidetaka; Yamaki, Kenichi*; Kita, Satoshi*; Yoshimoto, Hidemitsu*; et al.
JPS Conference Proceedings (Internet), 33, p.011041_1 - 011041_6, 2021/03
An Accelerator Driven System (ADS) for waste transmutation investigated in JAEA employs lead-bismuth eutectic (LBE) as a neutron production target material and coolant. The neutrons are to be produced via the spallation with 1.5 GeV proton beam injection. As materials irradiation data are important for ADS development, JAEA plans to construct an irradiation facility with LBE neutron production target in J-PARC. There are many technical issues on LBE for practical use. In JAEA, various R&Ds are being carried out. Concerning corrosion study, conditioning operation and functional tests of OLLOCHI started. Oxygen concentration control technology has also developing. In the large scale LBE loop experiment, the operation for steady state and transient experiments was performed by using IMMORTAL. In the area of instrument, development of ultrasonic flow meter and freeze seal valve are progressing as a key technology for the LBE loop system. Investigation of behavior of impurities in LBE, which is important for design of the irradiation facility, started. In this paper, the status of the LBE studies and experimental plan will be presented.
Obayashi, Hironari; Yoshimoto, Hidemitsu*; Kita, Satoshi*; Yamaki, Kenichi*; Wan, T.*; Saito, Shigeru; Sasa, Toshinobu
JPS Conference Proceedings (Internet), 33, p.011048_1 - 011048_6, 2021/03
Sasa, Toshinobu; Saito, Shigeru; Obayashi, Hironari; Ariyoshi, Gen
JPS Conference Proceedings (Internet), 33, p.011051_1 - 011051_6, 2021/03
To realize Accelerator-driven system (ADS) for minor actinide transmutation, JAEA proposes to construct the Proton Irradiation Facility in J-PARC. The facility is planned to solve technical issues for safe application of Lead-bismuth Eutectic Alloy (LBE). The 250 kW LBE spallation target will be located in the facility to prepare material irradiation database by both proton and neutron irradiation in the temperature range for typical LBE-cooled ADS. Various studies for important technologies required to build the facilities are investigated such as oxygen concentration control, instruments development, remote handling techniques for target maintenance, and spallation target design. The large scale LBE loops for mock up the 250 kW LBE spallation target and material corrosion studies are also manufactured and applied to various experiments. The latest status of 250 kW LBE spallation target design works will be summarized.
Yamaki, Kenichi*; Kita, Satoshi*; Obayashi, Hironari; Ariyoshi, Gen; Saito, Shigeru; Sasa, Toshinobu
JAEA-Technology 2020-021, 26 Pages, 2021/02
JAEA-Technology-2020-021.pdf:2.34MB
As digitalization of measuring instruments, Programmable Logic Controller is mainly used for controlling large-scale devices, and many test devices are controlled in digital. Together with increase of the data storage capacity, it has become possible to record the measured values over the entire experimental period. By collecting the entire experimental data, it became easy to appropriately record the test environment during the corrosion test of materials and to analyze the changes and transients during continuous operation from various viewpoints. On the other hand, in a long-term test, the large number of measurement data were recorded, which requires long time for data processing and data extraction for analyses. In addition, it is necessary to pay attention to organize the data collected by different data formats. To solve these problems, a processing tool were produced to extract and process the data efficiently from the sequencer installed in the lead-bismuth test device.
Saito, Shigeru; Suzuki, Kazuhiro; Hatakeyama, Yuichi; Suzuki, Miho; Dai, Y.*
Journal of Nuclear Materials, 534, p.152146_1 - 152146_16, 2020/06
Times Cited Count：1 Percentile：12.16(Materials Science, Multidisciplinary)A post-irradiation examination (PIE) was performed on the tensile specimens prepared from the MEGAPIE (MEGAwatt Pilot Experiment) target which were irradiated in flowing lead-bismuth eutectic (LBE). Thicknesses of the specimens were over two times larger than that of the standard specimen. The PIE revealed that the T91 specimens showed a 1.5-2.0 times larger total elongation (TE) compared to the literature values for a specimen with standard t/w (ratio of thickness to width). It could be suggested that the t/w and TE were strongly correlated. Then, we tried to investigate the effects of the t/w on the TE by comparing unirradiated specimens. We found that there was no t/w dependence on the strength and uniform elongation. On the other hand, the TE increases with increasing t/w. Based on the experimental data, we correlated the TE with various specimens t/w to estimate appropriate TE values, including that for the standard specimen.
Ohdaira, Naoya*; Saito, Shigeru
Heliyon (Internet), 6(2), p.e03429_1 - e03429_8, 2020/02
Times Cited Count：4 Percentile：39.81(Multidisciplinary Sciences)Lead-bismuth eutectic (LBE) is a candidate liquid metal coolant for a fast reactor, especially accelerator driven system (ADS). Freeze sealed valve is a candidate design to be possible to add passive safety to the reactor. On the other hand, since LBE is known that it causes expansion after its solidification, quantitative evaluation of the stress to the pipe produced by the LBE expansion should be considered. Many researchers produced related data for the expansion, however, evaluations of the strain by LBE expansion was barely reported. Therefore, the strain measurement using a stainless steel cup and the stress evaluation was performed together with visual observation using an optical microscopy. The results indicated keeping above room temperature (RT) was a significantly effective way to reduce the strain to the pipe.
Saito, Shigeru; Okubo, Nariaki; Obayashi, Hironari; Wan, T.; Sugawara, Takanori; Sasa, Toshinobu; Maekawa, Fujio
JPS Conference Proceedings (Internet), 28, p.071003_1 - 071003_6, 2020/02
Japan Atomic Energy Agency (JAEA) proposes transmutation of minor actinides (MA) by accelerator-driven systems (ADS). The ADS designed by JAEA is a system composed by LBE (Lead-Bismuth Eutectic) spallation target and a subcritical core. In the ADS, a beam window (BW) is exposed in complex field of heavy irradiation by proton/neutron and corrosion by flowing LBE. To develop ADS structural materials, it is of critical importance to investigate materials used in such environment. Thus, JAEA plans to construct a proton irradiation facility at the J-PARC to prepare an irradiation database for candidate ADS structural materials and to investigate irradiation effects in flowing LBE environment. In this paper, giving a whole scope of the JAEA ADS development, some results of experimental measurements and the specific program for planed R&D will be presented.
Takahashi, Hiroshi*; Minami, Masayo*; Aramaki, Takafumi*; Handa, Hiroko*; Kokubu, Yoko; Ito, Shigeru*; Kumamoto, Yuichiro*
Radiocarbon, 61(6), p.1879 - 1887, 2019/12
Times Cited Count：2 Percentile：11.66(Geochemistry & Geophysics)Water sample for interlaboratory comparison (here after "comparison water") must have inalterable 
C concentration during the comparison campaign and inter-batches homogeneity. In this study, the procedure for preparing of comparison water was discussed. We employed that comparison waters were artificially made by mixing chemical reagents, controlling C concentration and chemical composition. We could prepare six comparison waters, having 1, 14, 37, 56, 72 and 100 pMC, respectively. The stable carbon isotopic values and chemical compositions of some batches were measured to exanimate the inter- batches homogeneity. The C discrepancies among the batches were negligible for the inter-laboratory comparison. Finally, the results of trial comparison in Japan will be presented. Most of C results of CO
extracted by six laboratories showed good agreements each other.
Obayashi, Hironari; Yamaki, Kenichi; Kita, Satoshi; Yoshimoto, Hidemitsu; Wan, T.; Saito, Shigeru; Sasa, Toshinobu
Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.262 - 274, 2019/08
Construction of an experimental facility using LBE spallation target is under planning in the framework of J-PARC project to understand the compatibility of candidate ADS structural materials under flowing high temperature LBE environment with proton / neutron irradiation. We constructed a mock-up test loop, IMMORTAL to verify the feasibility of a primary cooling system in the target system. Including the layout considering remote maintainability, the same design as the actual JAEA's LBE target is reflected in most devices of IMMORTAL such as an electromagnetic pump (EMP), a heat exchanger and instrumentations. During the integrated tests, the individually developed devices of LBE loop system worked without significant malfunction. Several experimental data to verify the safety analysis model for LBE loop system using RELAP5-3D was acquired by simulation experiment of transient events such as beam over power and decrease of forced cooling.
Sakai, Kenji; Obayashi, Hironari; Saito, Shigeru; Sasa, Toshinobu; Sugawara, Takanori; Watanabe, Akihiko*
JAEA-Technology 2019-009, 18 Pages, 2019/07
JAEA-Technology-2019-009.pdf:2.34MB
Construction of Transmutation Experimental Facility (TEF) is under planning in the Japan Proton Accelerator Research Complex (J-PARC) program to promote R&D on the transmutation technology with using accelerator driven systems (ADS). ADS Target Test Facility (TEF-T) in TEF will develop spallation target technology and study on target materials with irradiating high intensity proton beams on a lead-bismuth eutectic (LBE) target. For safe and efficient beam operation, a general control system (GCS) will be constructed in TEF-T. GCS comprises several subsystems, such as a network system (LAN), an integral control system (ICS), an interlock system (ILS), and a timing distribution system (TDS) according to their roles. Especially, the ICS plays the important role that executes integral operations in the entire facility, acquires, stores and distributes operation data. We planned to develop a prototype of the ICS, to evaluate its concrete performances such as data transmission speeds, data storage capability, control functions, long-term stability of the system, and to utilize them for design of the actual ICS. This report mentions to product the prototype of ICS and to apply it to remote operations of instruments for developing LBE target technology.
Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count：8 Percentile：56.2(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 
Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Wan, T.; Saito, Shigeru
Metals, 8(8), p.627_1 - 627_22, 2018/08
Times Cited Count：17 Percentile：66.2(Materials Science, Multidisciplinary)Saito, Shigeru; Obayashi, Hironari; Wan, T.; Okubo, Nariaki; Sugawara, Takanori; Endo, Shinya; Sasa, Toshinobu
Proceedings of 13th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '17) (Internet), p.448 - 457, 2018/05
JAEA proposes transmutation of minor actinides by accelerator-driven systems (ADS). To obtain the data for ADS design, JAEA plans to construct the ADS Target Test Facility (TEF-T) within the framework of the J-PARC project. In TEF-T, a 250 kW proton-beam-driven LBE (Lead-Bismuth Eutectic) spallation target will be installed to prepare an irradiation database for candidate ADS structural materials. Design activities of the LBE target and target trolley have been progressed. Conceptual design of hot-cells for LBE target loop maintenance and PIE (Post Irradiation Examination) of irradiated samples have been finished. Two LBE loops were manufactured. One is a loop for TEF-T target mock-up and the other is that for collection of material corrosion characteristics in flowing LBE. Oxygen potential control systems for LBE flow have been also developed. Remote handling tests for the target exchange are underway. In this paper, current activities and studies to realize TEF-T will be presented.
