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Fukaya, Yuji; Goto, Minoru; Shibata, Taiju
IAEA-TECDOC-2040, p.133 - 136, 2023/12
Japan has developed back-end technologies to establish a multi-recycling fuel cycle with fast breeder reactors (FBRs) to ensure energy resources. Even though the development of FBR has been retreated to one of fundamental research, the reprocessing technologies for uranium fuel and disposal technologies had been completed for Light Water Reactor (LWR) fuel cycle on the process. These technologies were inherited to utilities and are about to be practical. Now, Japan had been completed High Temperature Engineering Test Reactor (HTTR) a prototype and research reactor, a commercial High Temperature Gas-cooled Reactor (HTGR) design Gas Turbine High Temperature Reactor 300 (GTHTR300) with related reprocessing technologies, and is planning domestic demonstration reactor project. In this context, a representative fuel cycle policy is reprocessing in Japan. However, Japan has investigated various fuel cycle scenarios to expand the usage of the commercial HTGR. Then, we would like to introduce the scenarios and development status of related technologies in the present study.
Shibata, Hiroshi; Takeuchi, Tomoaki; Seki, Misaki; Shibata, Akira; Nakamura, Jinichi; Ide, Hiroshi
JAEA-Data/Code 2021-018, 42 Pages, 2022/03
JAEA-Data-Code-2021-018.pdf:2.78MB
JAEA-Data-Code-2021-018-appendix(CD-ROM).zip:0.15MB
Japan Materials Testing Reactor (JMTR) in Oarai Research and Development Institute of the Japan Atomic Energy Agency has been developing various reactor materials, irradiation techniques and instruments for more than 30 years. Among them, the development of self-powered neutron detectors (SPNDs) and gamma detectors (SPGDs) has been carried out, and several research results have been reported. However, most of the results are based on the design study of the detector development and the results of in-core irradiation tests and gamma irradiation tests using Cobalt-60. In this report, a numerical code is developed based on the paper "Neutron and Gamma-Ray Effects on Self-Powered In-Core Radiation Detectors" written by H.D. Warren and N.H. Shah in 1974, in order to theoretically evaluate the self-powered radiation detectors.
Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950
C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Hirota, Noriaki; Shibata, Hiroshi; Takeuchi, Tomoaki; Otsuka, Noriaki; Tsuchiya, Kunihiko
Journal of Nuclear Science and Technology, 57(12), p.1276 - 1286, 2020/12
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)The influence of materials of mineral-insulated (MI) cables on their electrical characteristics upon exposure to high-temperature conditions was examined via a transmission test, in the objective of achieving the stability of the potential distribution along the cable length. Occurrence of a voltage drop along the cable was confirmed for aluminum oxide (Al
O
) and magnesium oxide (MgO), as insulating materials of the MI cable. A finite-element method (FEM)-based analysis was performed to evaluate the leakage in the potentials, which was found at the terminal end. Voltage drop yields by the transmission test and the analysis were in good agreement for the MI cable of AlO and MgO materials, which suggests the reproducibility of the magnitude relationship of the experimental results via the FEM analysis. To suppress the voltage drop, the same FEM analysis was conducted, the diameter of the core wires (
) and the distance between them (
) were varied. Considering the variation of , the potential distribution in the MI cable produced a minimum voltage drop corresponding to a ratio 
of 0.35, obtained by dividing with that of the insulating material (
). In case of varying , a minimum voltage drop was l/ of 0.5.
Fukaya, Yuji; Kasahara, Seiji; Mizuta, Naoki; Inaba, Yoshitomo; Shibata, Taiju; Nishihara, Tetsuo
JAEA-Research 2018-004, 38 Pages, 2018/06
JAEA-Research-2018-004.pdf:1.81MB
The demand of HTGR to investigate its introduction scenario and heat balance of HTGR have been researched. First, previous studies of HTGR demand were researched. Next, heat balance of GTHTR300, a commercial scale HTGR design, and its characteristics were researched. By using this information, installation number of HTGR to suit for demand in Japan are evaluated. In addition, heat balance evaluation code was developed in this study.
Nakano, Hiroko; Hirota, Noriaki; Shibata, Hiroshi; Takeuchi, Tomoaki; Tsuchiya, Kunihiko
Mechanical Engineering Journal (Internet), 5(2), p.17-00594_1 - 17-00594_12, 2018/04
no abstracts in English
Takeuchi, Tomoaki; Shibata, Hiroshi; Hanakawa, Hiroki; Uehara, Toshiaki*; Ueno, Shunji*; Tsuchiya, Kunihiko; Kumahara, Hajime*; Shibagaki, Taro*; Komanome, Hirohisa*
JAEA-Technology 2017-026, 26 Pages, 2018/02
JAEA-Technology-2017-026.pdf:4.0MB
Under severe accidents, high-integrity transmission techniques are necessary so as to monitor the situation of the nuclear power plant. In this study, effects of gamma irradiation up to 10
Gy on properties of optical devices were evaluated toward the development of a radiation-resistant in-water wireless transmission system using visible light. After the irradiation, for the LEDs, the total luminous flux decreased and the browning of resin lenses occurred. Meanwhile, the current-voltage characteristics hardly changed. For the PDs, the light sensitivity decreased and the browning of resin window occurred. The dark currents of PDs did not become large enough to adversely affect transmission. These results indicated that both the decreases of the total luminous flux of the LEDs and the light sensitivity of the PDs were mainly caused by not the degradation of the semiconductor parts but the browning of the resin parts by the irradiation. In addition, basic decrease behaviors of light transmission of several different types of glasses by gamma irradiation were also obtained so as to select the suitable optical windows and filters for the developing radiation-resistant in-water wireless transmission system.
Eguchi, Shohei; Shibata, Hiroshi; Imaizumi, Tomomi; Nagata, Hiroshi; Tanimoto, Masataka; Kusunoki, Tsuyoshi
JAEA-Review 2017-032, 26 Pages, 2018/02
JAEA-Review-2017-032.pdf:2.44MB
A practical training course using the JMTR and other research infrastructures was held from July 24th to August 4th in 2017 for Asian young researchers and engineers. This course was adopted as Japan-Asia Youth Exchange Program in Science (SAKURA Exchange Program in Science) which is the project of the Japan Science and Technology Agency, and this course aims to enlarge the number of high-level nuclear researchers/engineers in Asian countries which are planning to introduce a nuclear power plant, and to promote the use of facilities in future. In this year, 10 young researchers and engineers joined the course from 6 countries. This course consists of lectures, which are related to irradiation test research, safety management of nuclear reactors, nuclear characteristics of the nuclear reactors, etc., practical training such as practice of research reactor operation using simulator and technical tour of nuclear facilities on nuclear energy. The content of this course in FY 2017 is reported in this paper.
Shibata, Hiroshi; Nakano, Hiroko; Suzuki, Yoshitaka; Otsuka, Noriaki; Nishikata, Kaori; Takeuchi, Tomoaki; Hirota, Noriaki; Tsuchiya, Kunihiko
JAEA-Testing 2017-002, 138 Pages, 2017/12
JAEA-Testing-2017-002.pdf:9.3MB
From the viewpoints of utilization improvement of the Japan Materials Testing Reactor (JMTR), the experimental devices have been established for the out-pile tests in the irradiation technology development building. The devices for the irradiation capsule assembly, material tests and inspections were established at first and experimental data were accumulated before the neutron irradiation tests. On the other hand, after the Great East Japan Earthquake, the repairs and earthquake-resistant measures of the existing devices were carried out. New devices and equipments were also established for the R&D program for power plant safety enhancement of the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry (METI) and 
Mo/
Tc production development under the Tsukuba International Strategic Zone. This report describes the outline and basic operation manuals of the devices established from 2011 to 2016 and the management points for the safety works in the irradiation technology development building.
Eguchi, Shohei; Takemoto, Noriyuki; Shibata, Hiroshi; Tanimoto, Masataka; Kusunoki, Tsuyoshi
JAEA-Review 2017-007, 32 Pages, 2017/03
JAEA-Review-2017-007.pdf:3.19MB
A practical training course using the JMTR and other research infrastructures was held from July 25th to August 5th in 2016 for domestic and foreign young researchers and engineers. This course aims to enlarge the number of high-level nuclear researchers/engineers in Japan and foreign countries which are planning to introduce a nuclear power plant, and to promote the use of facilities in future. In this year, 13 young researchers and engineers joined the course from 7 countries. This course consists of lectures, which are related to irradiation test research, safety management of nuclear reactors, nuclear characteristics of the nuclear reactors, etc., practical training and technical tour of nuclear facilities on nuclear energy. At the end of the course, the trainees discussed the energy policy and prospect of each country, each country's research reactor, and trainee's current research. The content of this course in FY 2016 is reported in this paper.
Takeuchi, Tomoaki; Shibata, Hiroshi; Otsuka, Noriaki; Uehara, Toshiaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
IEEE Transactions on Nuclear Science, 63(5), p.2698 - 2702, 2016/10
Times Cited Count：3 Percentile：28.09(Engineering, Electrical & Electronic)In response to the lesson of the accident at the Fukushima Dai-ichi Nuclear Power Plant, we started a development of a radiation-resistant in-water wireless transmission system. In this study, capability of light emitting diodes (LED) and photo diodes (PD) as light emitting and receiving devices was researched. Results of irradiation tests of LEDs and PDs up to 1 MGy indicated a main cause of the degradation of the optical performances of the diodes was not the radiation damage at the semiconductor parts but the coloring of the resin parts. Assuming that the use of the candidate LED and PD, the PD's output current generated by the emission light of the LED at five meters away in water was estimated to be detectable intensity even considering the effects of the absorption of the light by water and the increased dark current by 1 MGy irradiation. Therefore, a radiation resistant in-water transmission system can be constructed using LEDs and PDs in principle.
Nakano, Hiroko; Shibata, Hiroshi; Takeuchi, Tomoaki; Matsui, Yoshinori; Tsuchiya, Kunihiko
Proceedings of International Conference on Asia-Pacific Conference on Fracture and Strength 2016 (APCFS 2016) (USB Flash Drive), p.283 - 284, 2016/09
no abstracts in English
Miura, Kuniaki*; Shibata, Hiroshi; Onizawa, Tatsuya*; Nakano, Hiroko; Takeno, Naofumi*; Takeuchi, Tomoaki; Tsuchiya, Kunihiko
Nihon Hozen Gakkai Dai-13-Kai Gakujutsu Koenkai Yoshishu, p.387 - 390, 2016/07
no abstracts in English
Eguchi, Shohei; Takemoto, Noriyuki; Shibata, Hiroshi; Naka, Michihiro; Nakamura, Jinichi; Tanimoto, Masataka; Ito, Haruhiko*
JAEA-Review 2016-001, 31 Pages, 2016/05
JAEA-Review-2016-001.pdf:9.05MB
Since fiscal 2011, a practical training course using the JMTR and other research infrastructures has been provided by Neutron Irradiation Testing Reactor Center for foreign young researchers and engineers in Asian and other countries which are planning to introduce power reactors. The aim of this course is to contribute to the human resource development in nuclear research field and to increase the future use the JMTR. On the other hand, a training course for Japanese young researchers and engineers has been conducted since fiscal 2010. These two separate courses were integrated. In fiscal 2015, this training course was conducted for 2 weeks and 17 young researchers and engineers from 7 countries were participated. They studied about the general outline of nuclear research, current status and R&D about nuclear energy, safety management of nuclear reactor, irradiation behavior of materials and fuels, facilities and technologies for irradiation and post irradiation, and nuclear characteristics of the reactor through lectures and practical trainings. At the end of the course, we had a discussion about the current status and future of energy mix and renewable energies of each country was discussed. The content of this training course in fiscal 2015 is reported in this paper.
Nakano, Hiroko; Uehara, Toshiaki; Takeuchi, Tomoaki; Shibata, Hiroshi; Nakamura, Jinichi; Matsui, Yoshinori; Tsuchiya, Kunihiko
JAEA-Technology 2015-049, 61 Pages, 2016/03
JAEA-Technology-2015-049.pdf:14.7MB
In Japan Atomic Energy Agency, we started a research and development so as to monitor the Nuclear Plant Facilities situations during a severe accident, such as a radiation-resistant monitoring camera under a severe accident, a radiation resistant in-water transmission system for conveying the information in-core and a heat-resistant signal cable. As part of advance in a heat-resistant signal cable, we maintained to ex-core high-temperature and pressure water loop test equipment which can be simulated conditions of BWRs and PWRs for evaluation reliability and property of construction sheath materials. This equipment consists of Autoclave, water conditioning tank, water pump, high-pressure metering pump, preheater, heat exchanger and pure water purification equipment. This report describes the basic design and the results of performance tests of construction machinery and tools of ex-core high-temperature and pressure water loop test equipment.
irradiationTakeuchi, Tomoaki; Shibata, Hiroshi; Otsuka, Noriaki; Uehara, Toshiaki; Kumahara, Hajime*; Tsuchiya, Kunihiko
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 29, 2016/02
irradiation effects on LEDs which were fabricated by different two fabricators and had relatively large amount of light were evaluated toward the development of a radiation-resistant in-water wireless transmission system using visible light. The current-voltage characteristics and total luminous flux of the LEDs were measured before and after the irradiation. After the irradiation, the total luminous flux decreased and the resin lenses turned oxblood. Meanwhile, the current-voltage characteristics hardly changed. These results indicated that the decreases of the total luminous flux of the LEDs were mainly caused by not the degradation of the semiconductor parts but the coloring of the resin parts by the irradiation. On the other hand, the decrease rates of the total lumious fluxes with absorbed dose of the LEDs fabricated one fabricator were smaller than the others. Therefore, they are possible candidates for the light emitting devices of the developing in-water transmission system.
Takeuchi, Tomoaki; Yamamoto, Keiichi; Otsuka, Noriaki; Shibata, Hiroshi; Shibata, Akira; Takemoto, Noriyuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Unesaki, Hironobu*; Fujihara, Yasuyuki*; et al.
KURRI Progress Report 2014, P. 108, 2015/07
Investigation of a relation between output power and brightness of Cherenkov light of a specific fuel element at KUR by a CCD camera was performed due to a development of a real-time in-core measurement technique using Cherenkov light. The results indicate that the inhomogeneous distribution of output power and the shadow of the control-rod guide tubes and the other irradiation equipment have significant effects on the brightness of the Cherenkov light. These effects could be suppressed by using a number of cameras located at various positions.
irradiationTakeuchi, Tomoaki; Hanakawa, Hiroki; Shibata, Hiroshi; Uehara, Toshiaki; Ueno, Shunji; Kumahara, Hajime*; Tsuchiya, Kunihiko
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 33, 2015/03
irradiation effects on LEDs and photo diodes (PDs) were evaluated toward the development of a radiation-resistant in-water wireless transmission system using visible light. The current-voltage characteristics and total luminous flux of the LEDs and the dark current and light sensitivity of the PDs were measured before and after the irradiation. After the irradiation, for the LEDs, the total luminous flux decreased and the resin lenses turned oxblood. Meanwhile, the current-voltage characteristics hardly changed. For the PDs, the light sensitivity decreased and the resin window turned oxblood while the dark currents stayed at most 10 nA. These results indicated that both the decreases of the total luminous flux of the LEDs and the light sensitivity of the PDs were mainly caused by not the degradation of the semiconductor parts but the coloring of the resin parts by the irradiation.
Takeuchi, Tomoaki; Otsuka, Noriaki; Shibata, Hiroshi; Nagata, Hiroshi; Endo, Yasuichi; Matsui, Yoshinori; Tsuchiya, Kunihiko
KAERI/GP-418/2015, p.110 - 112, 2015/00
irradiation experiments with a 
Co source were carried out for developing Self-Powered Gamma Detectors (SPGDs) with lead (Pb) emitter and Self-Powered Neutron Detectors (SPNDs) with Pt-40%Rh emitter prior to in-core irradiation experiments. The results showed the output currents of the SPGDs were proportional to the dose rate in the range from about 200-6000 Gy/h with about 10% accuracy. In the case of SPNDs, the output currents flowed in inverse direction and were an order of magnitude lower compared with that of the SPGDs. These different behaviors of the output currents are considered to be caused by the difference in the emitter sizes and the current component originated at the MI cables.
Fukaya, Yuji; Goto, Minoru; Shibata, Taiju
JAEA-Technology 2014-030, 29 Pages, 2014/08
JAEA-Technology-2014-030.pdf:17.7MB
A study on radiation damage calculation method for in-core structural material of HTGR had been performed. Firstly, a theory and a calculation method for radiation damage were investigated. Secondly, a DPA cross-section calculation method using NJOY, which is the typical reactor constants generation code, was established. Moreover, DPA calculation method was established. To evaluate these evaluations simply, calculation method was developed including the function of NPRIM which includes NJOY code as a solver and was developed in previous study. In addition, necessary items were identified to improve the method for accuracy.
