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Kamikawa, Yutaka; Suzuki, Makoto; Agake, Toshiki; Murakami, Takahiko; Morita, Yusuke; Shiina, Hidenori; Fukushima, Manabu; Hirane, Nobuhiko; Ouchi, Yasuhiro
JAEA-Technology 2023-030, 57 Pages, 2024/03
JAEA-Technology-2023-030.pdf:1.93MB
Owing to the publication of the latest data about aircraft crashes by Nuclear Regulation Authority (NRA), it was necessary to re-evaluate the probabilities of aircraft crashes for Nuclear Science Research Institute (NSRI). By using of the assessment method provided in "Regulatory Guide of the Assessment Standard for Probability of Airplane Crash on a Nuclear Power Reactor Facility", we re-evaluated the probabilities of aircraft crashes against the nuclear facilities in NSRI. As a result of the evaluations, the sum of the probabilities of aircraft crashes against Waste Treatment Facilities (maximum probability among all nuclear facilities in NSRI) is 5.68
10
(times/(reactor 
year)) which is lower than 10
(times/(reactor year)) that is the assessment criterion whether aircraft crashes is considered to be "anticipated external human induced events" in design basis or not.
Tokunaga, Sho; Iguchi, Shintaro; Kawamura, Sho; Hirane, Nobuhiko
JAEA-Technology 2022-004, 74 Pages, 2023/02
JAEA-Technology-2022-004.pdf:2.46MB
In JRR-3, in response to the new regulatory standard for research reactors that is enforced December 2013, we submitted the application document of reactor installation license for the JRR-3 on September 2014, and acquired the permission on November 2018. Thereafter, we carried out impact assessment for internal overflow based on the design principles as described in the application document of reactor installation license for the JRR-3. There are two legal requirements for internal overflow. The first is to ensure that the necessary safety functions are not lost due to internal overflow that occur in the facility. The second is to prevent leakage of liquid containing radioactive materials outside the radiation controlled area in the event of an internal overflow. For these requirements, assuming each overflow source, it was confirmed that the necessary safety functions would not be lost and that liquid containing radioactive materials would not leak outside the controlled area. Regarding these assessments, design and construction plans were submitted in installments, and the approvals were obtained sequentially. This report shows the result that is impact assessment for internal overflow in JRR-3.
Ishikuro, Yasuhiro; Hirane, Nobuhiko; Kato, Tomoaki
Proceedings of European Research Reactor Conference 2018 (RRFM 2018) (Internet), 7 Pages, 2018/03
Japan Research Reactor No.4 (JRR-4) is a swimming pool type reactor moderated and cooled with light-water. The maximum thermal power of JRR-4 is 3,500kW. Since its initial criticality in January 1965, JRR-4 had been operated about 45 years until in December 2010.Subsequently, the Great East Japan Earthquake occurred on March 11, 2011. Although JRR-4 was no severe damage, we have determined to decommission JRR-4 in consideration of various things. After that, we have submitted the decommissioning plan of JRR-4 to the nuclear regulatory body and have received the approval of it on June 7, 2017. Consequently, JRR-4 has shifted to the phase1 of the decommissioning plan since December.15, 2017 after the approval of its the safety regulation.
Ishikuro, Yasuhiro; Hirane, Nobuhiko; Kato, Tomoaki
Proceedings of 8th International Symposium on Materials Testing Reactors (ISMTR-8) (Internet), 5 Pages, 2015/10
Japan Research Reactor No.4 (JRR-4) is a swimming pool type reactor moderated and cooled with light-water. The maximum thermal power of JRR-4 is 3,500 kW. Since its initial criticality in January 1965, JRR-4 had been operated about 45 years until in December 2010. Subsequently, the Great East Japan Earthquake occurred on March 11, 2011. Although JRR-4 was no severe damage, we have determined to decommission JRR-4 in consideration of various things, and will submit the decommissioning plan of JRR-4 to the nuclear regulatory body in the near future.
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.
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
JAEA-Technology-2007-018.pdf:5.92MB
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
JAEA-Technology-2006-028.pdf:7.96MB
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
JAERI-Tech-2005-001.pdf:2.79MB
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.
Nio, Daisuke; Yagi, Masahiro; Hirane, Nobuhiko; Horiguchi, Hironori; Terakado, Yoshibumi
no journal, ,
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Sasaki, Tsutomu; Yagi, Masahiro; Hirane, Nobuhiko; Oyama, Koji
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Yonomoto, Taisuke; Nakatsuka, Toru; Hirane, Nobuhiko; Tsumura, Takashi
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Tsumura, Takashi; Hirane, Nobuhiko; Nakatsuka, Toru; Yonomoto, Taisuke
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Tsumura, Takashi; Hirane, Nobuhiko; Nakatsuka, Toru; Yonomoto, Taisuke
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no abstracts in English
