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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.
Takei, Hayanori; Furukawa, Kazuro*; Yano, Yoshiharu*; Ogawa, Yujiro*
Journal of Nuclear Science and Technology, 55(9), p.996 - 1008, 2018/09
Times Cited Count：2 Percentile：20.74(Nuclear Science & Technology)Experiences with existing high-power proton accelerators indicate that frequent beam trips are inevitable. One of the reasons for such frequent beam trips is the accidental interruption to protect accelerators against fatal failures. Generally, the failure frequency for the general machinery can be evaluated based on a reliability database for its components. On the other hand, the beam-trip frequency for the accidental interruption was not evaluated based on the reliability database because it has not yet been established. A principal reason for the lack of this reliability database is the inconsistency of data collection and analysis methods among laboratories. For example, there are at least three methods to estimate Mean Time Between accidental Interruptions (MTBI) for klystron systems. In the present study, the MTBI of the klystron systems of an electron/positron injector linac at the High Energy Accelerator Research Organization (KEK) was evaluated based on the reliability engineering method, in order to build the reliability database using the unified data collection and analysis method. As the result, the mean values of the MTBI by the traditional three methods were evaluated as 30.9, 32.0, and 50.4 hours. On the other hand, that by the reliability engineering method was evaluated as 57.3 hours, i.e., more than 1.14 times of the traditional results. Although these results are obviously different from traditional results, it appears that the present estimation based on the reliability engineering method is suitable for the MTBI of accelerator components as typified by the klystron system.
Ouchi, Nobuo; Akaoka, Nobuo*; Asano, Hiroyuki*; Chishiro, Etsuji; Namekawa, Yuya*; Suzuki, Hiroyuki*; Ueno, Tomoaki*; Noguchi, Shuichi*; Kako, Eiji*; Ouchi, Norihito*; et al.
Proceedings of 4th International Workshop on the Utilisation and Reliability of High Power Proton Accelerators, p.175 - 183, 2005/11
no abstracts in English
Takei, Hayanori
no journal, ,
Frequent beam trips as experienced in existing high-power proton accelerators may cause thermal fatigue in Accelerator-Driven System (ADS) components, which may lead to degradation of their structural integrity and reduction of their lifetime. In the previous study, the thermal transient analyses were performed to investigate the effects of beam trips on the reactor components. In order to consider methods to reduce beam-trip frequency, we compared the acceptable beam-trip frequency with the performance of the ADS accelerator, which was estimated based on the operational data on existing accelerators, the Los Alamos Neutron Science Center (LANSCE) and the High Energy Accelerator Research Organization (KEK). The comparison showed that for beam trips with durations exceeding 10 s, beam-trip frequencies were about 6 to 35 times larger than acceptable values. In the present study, the operational data on J-PARC Linac were newly analyzed and probability density functions (pdf) of beam trips for the ion source and the accelerator tube of the J-PARC Linac was obtained. Using the Monte Carlo method based on the beam-trip pdf, the beam-trip frequencies of the ADS accelerator were estimated. As the result of the estimation, the beam-trip frequencies with durations exceeding 10 s were less than the previous values, but about 3 to 10 times larger than acceptable values. In the presentation, the reliability of the accelerator tube to satisfy the acceptable beam-trip frequency will be mentioned.
Morita, Yasuji
no journal, ,
Status of research and development of partitioning and transmutation technologies by double strata concept conducted in Nuclear Science and Engineering Center are presented, including technologies for accelerator driven system, minor actinide (MA) separation from high-level liquid waste, MA fuel fabrication and irradiated MA fuel reprocessing.
Takei, Hayanori
no journal, ,
Frequent beam trips as experienced in existing high-power proton accelerators may cause thermal fatigue in Accelerator-Driven System (ADS) components, which may lead to degradation of their structural integrity and reduction of their lifetime. In the previous study, the thermal transient analyses were performed to investigate the effects of beam trips on the reactor components. In order to consider methods to reduce beam-trip frequency, we compared the acceptable beam-trip frequency with the performance of the ADS accelerator, which was estimated based on the operational data on existing accelerators, the Los Alamos Neutron Science Center (LANSCE) and the High Energy Accelerator Research Organization (KEK). The comparison showed that for beam trips with a duration of 10 s or less, the beam-trip frequency was acceptable. On the other hand, for beam trips with durations exceeding 10 s, beam-trip frequencies were about 6 to 35 times larger than acceptable values. In the present study, the operational data on J-PARC Linac were newly analyzed and probability density functions (pdf) of beam trips for the ion source and the accelerator tube of the J-PARC Linac was obtained. Using the Monte Carlo method based on the beam-trip pdf, the beam-trip frequencies of the ADS accelerator were estimated. As the result of the estimation, it was found that the type of the beam-trip pdf was the initial failure type, i.e., the beam-trip frequency for the ion source and the accelerator tube was larger at the beginning and decreased monotonously with the operation time. And the beam-trip frequency of the ADS accelerator with a duration of 10 s or less was acceptable, as same as the previous value. On the other hand, beam-trip frequencies with durations exceeding 10 s were less than the previous values, but about 3 to 10 times larger than acceptable values.
Iwamoto, Hiroki; Nishihara, Kenji; Katano, Ryota*; Fujimoto, Atsushi*
no journal, ,
no abstracts in English
Iwamoto, Hiroki; Nishihara, Kenji; Iwamoto, Yosuke; Hashimoto, Shintaro; Sato, Tatsuhiko
no journal, ,
no abstracts in English
Sato, Takumi; Nishi, Tsuyoshi*; Shirasu, Noriko; Kurata, Masaki; Yamashita, Yuichiro*
no journal, ,
no abstracts in English
Okubo, Nariaki; Saito, Shigeru; Obayashi, Hironari; Sasa, Toshinobu
no journal, ,
In the ADS plant, the target window material will be heavily irradiated under the severe condition. Degradation of the mechanical properties, size change of the components and erosion/corrosion of the material surface after irradiation in the LBE flow should be suppressed within a range permissible for the ADS system design. Material irradiation experiments in the transmutation experimental facility (TEF-T), which is planned in JAEA, will realize the first ADS plant in near future. Overview of the material irradiation and PIE plan by using TEF-T including R&D of LBE corrosion test loop and elemental key technology toward TEF-T and ADS will be shown in this presentation. In order to select candidate materials prior to TEF-T irradiation, triple ion irradiations of Fe, He and H ions were conducted for ferritic/martensitic steels, T91 in TIARA. The swelling behavior of T91 irradiated at temperature from 350 to 550
C will be also discussed.
Tsubata, Yasuhiro
no journal, ,
Recent research and development activities in the JAEA-NUCEF are introduced. After explanation of several research equipments in the NUCEF, research activities for partitioning and transmutation of the radioactive waste (group partitioning of liquid waste, ADS, and transmutation fuel cycle for ADS), non-destructive assay and chemical analysis technology are introduced.
Okubo, Nariaki; Kondo, Keietsu; Kitamura, Akane; Okuno, Yasuki
no journal, ,
Research and development of ADS and TEF-T have been done by JAEA. ADS and TEF-T adopt liquid lead bismuth eutectic (LBE) for both spallation target and coolant for the non-critical core. Irradiation and corrosion behaviors of steel materials in LBE are one of the important issues. High energy proton beam and spallation neutron irradiation will cause high dose of displacement damage and high concentration of transmutation gas, helium and hydrogen, simultaneously, in the target window material. At once, the materials will be influenced by the corrosion and erosion, which depends on the irradiation temperature and oxygen concentration in LBE, under LBE flow. Then, the irradiation data for material properties of corrosion/erosion and mechanical changes in flowing LBE is necessary to design and evaluate lifetime of ADS components. It is possible that the TEF-T facility will achieve the irradiation, which covers the ADS conditions of temperature from 450 to 550 and the displacement damage up to 20 dpa as designed for ADS target window. Material issues for the target window, irradiation plan of TEF-T, and the present activities for material test proceeded in static LBE pot and LBE loop systems will be presented.
Oigawa, Hiroyuki
no journal, ,
JAEA is conducting research and development on Partitioning and Transmutation technology, aiming at reduction of burden for high-level radioactive wastes. To transmute minor actinides such as neptunium and americium effectively, irradiation of them by fast neutrons is considered as a promising way, because fission reactions can directly transmute them. For this purpose, JAEA is developing an Accelerator-Driven System (ADS), which is a hybrid nuclear system coupling a subcritical reactor with a spallation neutron source driven by a high-power proton accelerator.
Watanabe, Nao; Sugawara, Takanori; Nishihara, Kenji
no journal, ,
In order to design an accelerator driven system (ADS), a beam window, which divides between areas of an accelerator and a subcritical core, is one of important structures. JAEA made a 3D model of a beam window and surrounding lead bismuth thermal flow field and developed a coupled analysis system of thermal hydraulics and structure in ANSYS Workbench. In the system a heat generation distribution from PHITS code is read, and steady thermal hydraulic of LBE coolant and stress of the beam window are calculated by Fluent code. Then its eigenvalue buckling is evaluated. In 3D analyses, non-axisymmetric evaluations are considered and radial deformations are found in low buckling modes.
Watanabe, Nao; Sugawara, Takanori; Okubo, Nariaki; Nishihara, Kenji
no journal, ,
no abstracts in English
Nakano, Keita; Meigo, Shinichiro; Takeshita, Hayato*; Matsuda, Hiroki; Iwamoto, Hiroki; Maekawa, Fujio
no journal, ,
Accelerator-driven nuclear transmutation system (ADS) is one of the promising options to solve the nuclear issue of the high-level radioactive waste disposal. Nuclide production cross sections of Pb and Bi, which play an important role as a spallation target and coolant, are necessary to evaluate the residual activity and to investigate the behavior of impurities. In this presentation, measured nuclide production cross sections of Bismuth by GeV proton irradiation will be presented together with theoretical calculations.
Nakano, Keita; Iwamoto, Hiroki; Meigo, Shinichiro; Nishio, Katsuhisa; Ishi, Yoshihiro*; Hirose, Kentaro; Iwamoto, Yosuke; Kuriyama, Yasutoshi*; Maekawa, Fujio; Makii, Hiroyuki; et al.
no journal, ,
For accurate prediction of neutronic characteristics for accelerator-driven system (ADS), an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University has been launched. As a part of this program, energy spectra of spallation neutron from 100-MeV proton-induced reactions on Fe, Pb, and Bi are plan to be measured. In this report, the results of the measurement on Fe target will be presented.
Nakano, Keita
no journal, ,
Accelerator driven transmutation system (ADS) is a promising technology for the treatment of high-level radioactive wastes. We propose a new experiment to measure the isotope production cross section in the proton incident reactions on Pb and Bi isotopes, which play an important role in the design of ADS.
Watanabe, So; Sasa, Toshinobu; Owada, Hitoshi*; Saito, Takumi*; Ishio, Takahiro*; Murakami, Tsuyoshi*; Shimada, Takashi*
no journal, ,
no abstracts in English
Nakano, Keita; Iwamoto, Hiroki; Meigo, Shinichiro; Nishio, Katsuhisa; Ishi, Yoshihiro*; Hirose, Kentaro; Iwamoto, Yosuke; Kuriyama, Yasutoshi*; Maekawa, Fujio; Makii, Hiroyuki; et al.
no journal, ,
Toward the realization of Accelerator-Driven System (ADS), we have been measuring the nuclear data for ADS using Kyoto University FFAG accelerator. In this presentation, we report the outline and the results of the energy spectrum measurement of neutrons produced by 107 MeV proton-induced reactions on lead and bismuth, which are the most important nuclides in ADS.
