Tokunaga, Sho; Horiguchi, Hironori; Nakamura, Takemi
JAEA-Technology 2023-001, 37 Pages, 2023/05
The cold neutron source (CNS) of the research reactor JRR-3 converts thermal neutrons generated in the reactor into low-energy cold neutrons by moderating them with liquid hydrogen stored in the moderator cell. Cold neutrons generated by the CNS are transported to experimental instruments using neutron conduits, and are used for many studies of physical properties, mainly in life science, polymer science, environmental science, etc. Improvement of cold neutron intensity is essential to maintain competitiveness with the world's research reactors in neutron science, and we are developing a new CNS that incorporates new knowledge. The current moderator cell for the CNS of JRR-3 is a stainless-steel container which is a canteen bottle type, and the cold neutron intensity can be improved by changing the material and shape. Therefore, the basic specifications of the new moderator cell were changed to aluminum alloy which has a smaller neutron absorption cross section, and the shape was optimized using a Monte Carlo code MCNP. Since these changes in specifications will result in changes in heat generation and heat transfer conditions, the CNS of JRR-3 was re-evaluated in terms of self-regulating characteristic, heat transport limits, heat resistance and pressure resistance, etc., to confirm its feasibility in thermal-hydraulic design. This report summarizes the results of the thermal-hydraulic design evaluation of the new moderator cell.
Yonomoto, Taisuke; Nakashima, Hiroshi*; Sono, Hiroki; Kishimoto, Katsumi; Izawa, Kazuhiko; Kinase, Masami; Osa, Akihiko; Ogawa, Kazuhiko; Horiguchi, Hironori; Inoi, Hiroyuki; et al.
JAEA-Review 2020-056, 51 Pages, 2021/03
A group named as "The group for investigation of reasonable safety assurance based on graded approach", which consists of about 10 staffs from Sector of Nuclear Science Research, Safety and Nuclear Security Administration Department, departments for management of nuclear facility, Sector of Nuclear Safety Research and Emergency Preparedness, aims to realize effective graded approach (GA) about management of facilities and regulatory compliance of JAEA. The group started its activities in September, 2019 and has had discussions through 10 meetings and email communications. In the meetings, basic ideas of GA, status of compliance with new regulatory standards at each facility, new inspection system, etc were discussed, while individual investigation at each facility were shared among the members. This report is compiled with expectation that it will help promote rational and effective safety management based on GA by sharing contents of the activity widely inside and outside JAEA.
Horiguchi, Hironori*; Sato, Tatsuhiko; Kumada, Hiroaki*; Yamamoto, Tetsuya*; Sakae, Takeji*
Journal of Radiation Research, 56(2), p.382 - 390, 2015/03
For evaluating the irradiation effect in tumors and surrounding normal tissues in BNCT, it is of great importance to estimate the relative biological effectiveness (RBE) for each dose component in the same framework. We have therefore established a new method for estimating the RBE of all BNCT dose components on the basis of the microdosimetric kinetic model. This method employs the probability densities of lineal energy, y, in a subcellular structure as the index for expressing RBE, which can be calculated using the microdosimetric function implemented in the particle transport simulation code PHITS. The accuracy of this method was tested by comparing the calculated RBE values with corresponding measured data in a water phantom irradiated with an epithermal neutron beam. The calculation technique developed in this study will be useful for biological dose estimation in the treatment planning of BNCT.
Nakamura, Takemi; Horiguchi, Hironori; Yanagie, Hironobu*; Arai, Masaji
JAEA-Technology 2014-016, 61 Pages, 2014/06
In the department of research reactor and tandem accelerator, developments of irradiation technique with application enlargement for breast cancer on BNCT have been performed in the second medium term plans. We compiled this report about the technological development to solve several problems with the irradiation of breast cancer in the medical irradiation facility of JRR-4. In the present study, design fabrication of a collimator for breast cancer, dose evaluation analysis by clinical model, investigation of dose enhancement at deeper region and investigation of fixing method for breast cancer irradiation were studied. By these evaluation results, we verified that the developed breast cancer irradiation technique can be applied to BNCT medical irradiation of JRR-4. These results are expected to be able to contribute to breast cancer irradiation techniques of other reactor-based BNCT and future accelerator-based BNCT.
Horiguchi, Hironori; Nakamura, Takemi; Motohashi, Jun; Kashimura, Takanori; Ichimura, Shigeju; Sasajima, Fumio
JAEA-Technology 2012-003, 38 Pages, 2012/03
Clinical trials of boron neutron capture therapy (BNCT) for malignant brain tumors and head and neck cancers have been performed at the research reactor JRR-4. BNCT is a kind of radiation therapy using a nuclear reaction with thermal neutrons and boron (B) elements administered to a patient. The design specifications of all types of reflector elements were changed due to a trouble of a reflector element in JRR-4. In the production of the new reflector elements, they were designed with the influence for the neutron beam facility by the analytical calculation. After the installation of the new reflector elements, the performance of the neutron beam facility was verified by measurement such as a free air experiment and a water phantom experiment. The calculation error used in the treatment planning for BNCT can be estimated by comparing the results of our calculation with the corresponding experimental data.
Horiguchi, Hironori; Nakamura, Takemi; Kumada, Hiroaki*; Yanagie, Hironobu*; Suzuki, Minoru*; Sagawa, Hisashi
Proceedings of 14th International Congress on Neutron Capture Therapy (ICNCT-14) (CD-ROM), p.234 - 237, 2010/10
Recurrent breast cancer has been considered the application for boron neutron capture therapy using the JRR-4. The investigation of irradiation conditions for the recurrent breast cancer was performed by simulation with the JCDS. We performed the preliminary dosimetry of the model to verify the efficient irradiation conditions such as the neutron energy modes and multiple field technique. From the result, when the 30 Gy-Eq dose as minimum dose was delivered to the cancers, comparable dose distribution was delivered at the healthy tissues by both a one-port irradiation from anterior direction and a two-port irradiation from tangential direction. We revealed that the two-port irradiation was not valid to reduce the healthy tissues dose due to the isotopic scattering of neutrons in the body. We concluded that the optimal irradiation condition was the one-port irradiation with thermal neutron beam mode in terms of less healthy tissues dose and shorter irradiation time.
Nakamura, Takemi; Horiguchi, Hironori; Kishi, Toshiaki; Motohashi, Jun; Sasajima, Fumio; Kumada, Hiroaki*
Proceedings of 14th International Congress on Neutron Capture Therapy (ICNCT-14) (CD-ROM), p.379 - 382, 2010/10
The clinical trials of BNCT have been conducted using JRR-4. The JRR-4 stopped in January 2008, because the graphite reflector was considerably damaged. For this reason, the specifications of graphite reflectors were renewal. All existing graphite reflectors of JRR-4 were changed by new graphite reflectors. The resumption of JRR-4 was carried out with new graphite reflectors in February 2010. We measured the characteristics of neutron beam at the JRR-4 Neutron Beam Facility. A cylindrical water phantom was put the gap for 1cm from the beam port. TLD and gold wire were inserted within the phantom when the phantom was irradiated. The results of the measured thermal neutron flux and the dose in water were compared with MCNP calculations. The calculated results showed the same tendency with the experimental results. These results are proceeding well and will be reported in full paper at July 2010.
Kumada, Hiroaki*; Nakamura, Takemi; Horiguchi, Hironori; Matsumura, Akira*
Proceedings of 14th International Congress on Neutron Capture Therapy (ICNCT-14) (CD-ROM), p.414 - 417, 2010/10
Sakata, Mami; Yagi, Masahiro; Horiguchi, Hironori; Hirane, Nobuhiko
Nihon Hozen Gakkai Dai-6-Kai Gakujutsu Koenkai Yoshishu, p.275 - 278, 2009/08
A crack was found on a weld area of one reflector element in JRR-4 on December 28, 2007. The following examinations were carried out, visual examination, dimensional examination, fractography examination and so on. It was concluded that the main cause of the crack is the neutron-induced swelling of graphite in the reflector element. We tested radiographycally the other reflector elements. As the result, we determined that many of them were not in a suitable state to be used because of swelling of graphite. Based on the relation between the irradiation dose and swelling rate, the design of the new reflector elements has been carried out. We decided to test radiographycally all the new reflector elements as the future maintenance.
Horiguchi, Hironori; Yamamoto, Kazuyoshi; Kishi, Toshiaki; Otake, Shinichi*; Kumada, Hiroaki*
JAEA-Research 2009-015, 38 Pages, 2009/07
The boron neutron capture therapy (BNCT) has been conducted at JRR-4. There is an increased number of cases due to the expansion of application against head and neck cancer and skin cancer. Therefore, the BNCT requires the establishment of procedure to perform more cases in a day. The determination of boron concentration in blood is important to determine the prescribed dose given to a patient. Currently, prompt ray analysis (PGA) is applied to the determination of boron concentration. But the PGA is not applied to more than three times BNCT a day. Therefore, swiftness and precision method by inductively coupled plasma atomic emission spectrometry (ICP-AES) is studied. Using BSH for Boron standard of the ICP-AES, we enabled to analyze accurately without an intricate sample preparation. The measurement precision of the ICP-AES was within 5% by the correction factor based on the PGA. We established the method of swiftness determination of boron concentration in blood for BNCT.
Yagi, Masahiro; Horiguchi, Hironori; Yokoo, Kenji; Oyama, Koji; Kusunoki, Tsuyoshi
JAEA-Technology 2008-072, 79 Pages, 2008/09
A crack had been found on the weld of one reflector element in JRR-4. A survey revealed that the cause for the crack was the expansion of graphite reflector in the reflector element. It appeared that the expansion of graphite reflector was caused by fast neutron irradiation at low temperature. The survey confirmed radiographically that graphite reflectors in the other reflector elements without the crack expanded similarly by the irradiation growth. Irradiated graphite reflectors were carefully observed and were precisely measured the three dimensions after dismantling the irradiated reflector elements in order to understand quantitatively the irradiation growth behavior of IG-110 graphite under the JRR-4 operation condition. As the results, it was confirmed that growth of graphite reflectors increased with increasing of fast neutron fluence. The maximum irradiation growth per fast neutron fluence was 7.1310%m/n, the minimum was 4.2110%m/n, the average was 5.7110%m/n in the range of fast neutron fluence below 2.510n/m.
Yokoo, Kenji; Horiguchi, Hironori; Yagi, Masahiro; Nagadomi, Hideki; Yamamoto, Kazuyoshi; Sasajima, Fumio; Oyama, Koji; Ishikuro, Yasuhiro; Sasaki, Tsutomu; Hirane, Nobuhiko; et al.
JAEA-Technology 2007-018, 104 Pages, 2007/03
Reactor operation training using JRR-4 (Japan Research Reactor No.4) was started in FY 1969, one of the curriculums of Nuclear Technology and Education Center (NuTEC). After that, the program was updated and carried out for reactor operation training, control rod calibration, and measurement of various kind of characteristics. JRR-4 has been contributed for nuclear engineer training that is over 1,700 trainees from bother domestic and foreign countries. JRR-4 can be used for experiment from zero power to 3500kW, and the trainees can make experience to operate the reactor from start up to shut down, not only zero-power experiments (critical approach, control rod calibration, reactivity measurement, etc.) but also other experiments under high power operation (xenon effect, temperature effects, reactor power calibration, etc.). This report is based on various kinds of guidance texts using for training, and collected for operation and experiments for reactor physics.
Hirane, Nobuhiko; Ishikuro, Yasuhiro; Nagadomi, Hideki; Yokoo, Kenji; Horiguchi, Hironori; Nemoto, Takumi; Yamamoto, Kazuyoshi; Yagi, Masahiro; Arai, Nobuyoshi; Watanabe, Shukichi; et al.
JAEA-Technology 2006-028, 115 Pages, 2006/03
JRR-4, a light-water-moderated and cooled, swimming pool type research reactor using high-enriched uranium plate-type fuels had been operated from 1965 to 1996. In order to convert to low-enriched-uranium-silicied fuels, modification work had been carried out for 2 years, from 1996 to 1998. After the modification, start-up experiments were carried out to obtain characteristics of the low-enriched-uranium-silicied fuel core. The measured excess reactivity, reactor shutdown margin and the maximum reactivity addition rate satisfied the nuclear limitation of the safety report for licensing. It was confirmed that conversion to low-enriched-uranium-silicied fuels was carried out properly. Besides, the necessary data for reactor operation were obtained, such as nuclear, thermal hydraulic and reactor control characteristics. This report describes the results of start-up experiments and burnup experiments. The first criticality of low-enriched-uranium-silicied core was achieved on 14th July 1998, and the operation for joint-use has been carried out since 6th October 1998.
Horiguchi, Hironori; Oyama, Koji; Ishikuro, Yasuhiro; Hirane, Nobuhiko; Ito, Kazuhiro; Kameyama, Iwao
JAERI-Tech 2005-001, 38 Pages, 2005/02
After JRR-4 heat exchanger was renewed in made of stainless steel from carbon steel, it was examined how to manage the heat exchanger. The main subject is the cleaning technology of the heat exchanger. The recovery of old heat exchanger cooling performance has been by only chemical cleaning. Now we use chemical and dry cleaning as a new technique. It helps prevent of corrosions of secondary pipes and reduce of management costs. This report describes the performance management and cleaning technology of the JRR-4 heat exchanger and the management of the JRR-4 coolant.
Komeda, Masao; Horiguchi, Hironori; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Suzuki, Minoru*
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no abstracts in English
Horiguchi, Hironori; Shibata, Taiju; Yagi, Masahiro; Yokoo, Kenji; Oyama, Koji; Kusunoki, Tsuyoshi
no journal, ,
The Japan Research Reactor No.4 (JRR-4) are used for medical irradiation (Boron Neutron Capture Therapy), education and training for engineers, activation analysis and researches in various fields. A crack was found on the weld of aluminum cladding of a reflector element, in which graphite reflector was set. A survey on the reflector element confirmed that the crack was caused by growth of graphite. The growth of graphite was observed in the other reflector elements by the radiographic testing (RT). In order to understand the relations between irradiation fluence and irradiation growth, the dimensions of irradiated graphite reflectors were precisely measured after dismantling the reflector elements. We revealed that the growth of graphite increased with fast neutron fluence at low temperature which was estimated below 200C under JRR-4 operation condition.
Yokoo, Kenji; Yagi, Masahiro; Horiguchi, Hironori; Oyama, Koji; Kusunoki, Tsuyoshi
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Nakamura, Takemi; Komeda, Masao; Horiguchi, Hironori; Kumada, Hiroaki; Wada, Shigeru
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Horiguchi, Hironori; Yamamoto, Kazuyoshi; Kishi, Toshiaki; Wada, Shigeru
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Nio, Daisuke; Yagi, Masahiro; Hirane, Nobuhiko; Horiguchi, Hironori; Terakado, Yoshibumi
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no abstracts in English