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Journal Articles

Development of the treatment method for difficult wastes aimed at decommissioning of JMTR; Structural materials of reactor and used ion-exchange resins

Seki, Misaki; Nakano, Hiroko; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Takeuchi, Tomoaki; Ide, Hiroshi; Tsuchiya, Kunihiko

Dekomisshoningu Giho, (62), p.9 - 19, 2020/09

Japan Materials Testing Reactor (JMTR) has been contributing to various research and development activities such as the fundamental research of nuclear materials/fuels, safety research and development of power reactors, and radioisotope production since the beginning of the operation in 1968. JMTR, however, was decided as a one of decommission facilities in April 2017 and it is taken an inspection of a plan concerning decommissioning because the performance of JMTR does not confirm with the stipulated earthquake resistance. As aluminum and beryllium are used for the core structural materials in JMTR, it is necessary to establish treatment methods of these materials for the fabrication of stable wastes. In addition, a treatment method for the accumulated spent ion-exchange resins needs to be examined. This report describes the overview of these examination situations.

JAEA Reports

On-site training using JMTR and related facilities in FY2018

Eguchi, Shohei; Nakano, Hiroko; Otsuka, Noriaki; Nishikata, Kaori; Nagata, Hiroshi; Ide, Hiroshi; Kusunoki, Tsuyoshi

JAEA-Review 2019-012, 22 Pages, 2019/10

JAEA-Review-2019-012.pdf:3.37MB

A practical training course using the JMTR and other research infrastructures was held from July 31st to August 7th in 2018 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, 11 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 2018 is reported in this paper.

Journal Articles

Development of radiation resistant monitoring system in light water reactor

Takeuchi, Tomoaki; Otsuka, Noriaki; Nakano, Hiroko; Iida, Tatsuya*; Ozawa, Osamu*; Shibagaki, Taro*; Komanome, Hirohisa*; Tsuchiya, Kunihiko

QST-M-16; QST Takasaki Annual Report 2017, P. 67, 2019/03

no abstracts in English

Journal Articles

High-temperature oxidation of sheath materials using mineral-insulated cables for a simulated severe accident

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

JAEA Reports

Establishment of experimental equipments in irradiation technology development building, 2

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 $$^{99}$$Mo/$$^{99m}$$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.

Journal Articles

Effect of dissolved gas on mechanical property of sheath material of mineral insulated cables under high temperature and pressure water

Takeuchi, Tomoaki; Nakano, Hiroko; Uehara, Toshiaki; Tsuchiya, Kunihiko

Nuclear Materials and Energy (Internet), 9, p.451 - 454, 2016/12

 Times Cited Count:1 Percentile:14.27(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Corrosion property of sheath materials using MI cables at conditions simulated severe accident

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

Journal Articles

Effect of dissolved gases on mechanical property of AISI 304 and 316 stainless steels under high temperature and pressure water

Takeuchi, Tomoaki; Nakano, Hiroko; Uehara, Toshiaki; Tsuchiya, Kunihiko

Proceedings of International Conference on Asia-Pacific Conference on Fracture and Strength 2016 (APCFS 2016) (USB Flash Drive), p.95 - 96, 2016/09

Monitoring system of the nuclear power plants during a severe accident has increased in importance after the accident at the Fukushima Dai-ichi Nuclear Power Plant. As part of the system, the development of mineral insulated (MI) cables available under the normal and severe environments was started. In this study, in order to investigate mechanical integrity of MI cables in reactor coolant condition, effects of dissolved oxygen on fracture properties of the sheath materials of the MI cables in high temperature and pressure pure water were evaluated. As the sheath materials, AISI 304 and 316 stainless steels were selected and slow strain rate testing was performed at 5$$times$$10$$^{-3}$$ mm/min in strain rate in pure water at 325$$^{circ}$$C and 15 MPa. In both the cases of the 304 and 316 steel, from 8500 to 50 ppb dissolved oxygen (DO), fully ductile fracture surfaces were observed and tensile strength and breaking elongation were almost the same values. However, at 10 and 1 ppb DO, brittle fracture surfaces were observed around the outer edge of the samples, and the tensile strength and breaking elongation decreased. The results indicated the existence of a threshold level of DO for brittle fracture of both the steels at lower than 100 ppb.

Journal Articles

R&D of high-temperature resistance type mineral insulated cable for sever accident

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

JAEA Reports

Performance test of ex-core high temperature and high pressure water loop test equipment (Contract research)

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.

JAEA Reports

Performance tests of radiation detectors for inspection of $$^{99}$$Mo/$$^{99m}$$Tc solution, 1

Suzuki, Yumi*; Nakano, Hiroko; Suzuki, Yoshitaka; Ishida, Takuya; Shibata, Akira; Kato, Yoshiaki; Kawamata, Kazuo; Tsuchiya, Kunihiko

JAEA-Technology 2015-031, 58 Pages, 2015/11

JAEA-Technology-2015-031.pdf:14.57MB

Technetium-99m ($$^{99m}$$Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. In the Japan Atomic Energy Agency (JAEA), the research and development (R&D) have been carried out for production of molybdenum-99 ($$^{99}$$Mo) by (n, $$gamma$$) method, a parent nuclide of $$^{99m}$$Tc, with the Japan Material Testing Reactor (JMTR). On the other hand, the new project as "Domestic Production of Medical Radioisotope (Technetium preparation) in Japan" was adopted in the Tsukuba International Strategic Zone on October, 2013 and the demonstration tests will be planned for the domestic production of $$^{99}$$Mo/$$^{99m}$$Tc with the JMTR. Thus, new facilities and analysis devices were equipped in the JMTR hot laboratory in 2014 as the part of this project. As the part of the analytical device equipment, the $$gamma$$-TLC analyzer and the radiation detector connected with the High Performance Liquid Chromatography (HPLC) were installed for quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc solution and the extracted $$^{99m}$$Tc solution in the JMTR hot laboratory. The performance tests of these devices such as detection sensitivity, resolution, linearity and selectivity of energy range were carried out with $$^{137}$$Cs and $$^{152}$$Eu as alternative radionuclides of $$^{99}$$Mo and $$^{99m}$$Tc, respectively. In the results, bright prospects were obtained concerning the quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc and $$^{99m}$$Tc solutions using these devices. This report describes the results of those performance tests.

Oral presentation

Analysis of dose-response in bystander effects between human lung normal and cancer cells

Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kanai, Tatsuaki*; Nakano, Takashi*; Kobayashi, Yasuhiko

no journal, , 

Human lung normal fibroblasts WI-38 and human lung cancer cells H1299/wt${it p53}$ were used. Cells were irradiated with carbon-ion broad beams (LET=108 keV/ $$mu$$m), then survival rates of bystander cells after co-culture with irradiated cells were measured using colony formation assay. The survival rates of non-irradiated H1299/wt${it p53}$ cells co-cultured with 0.13 Gy irradiated WI-38 increased after 6 and 24 h of co-culture. On the other hand, the bystander cells co-cultured with 0.5 Gy irradiated WI-38 showed decreased survival rates. The survival rates of bystander H1299/wt${it p53}$ cells showed a tendency to increase by the addition of Carboxy-PTIO to the co-culture medium, when co-cultured with 0.5 Gy irradiated WI-38. From these results, reduction of survival rates is likely to be caused by NO radical as a mediator in bystander effects between lung normal and cancer cells. However, it is suggested that there might be other signals participated in an increase of survival rates.

Oral presentation

Research and development of high-performance monitoring systems for safety measures of LWRs, 5; Mechanical properties of metal sheath materials for high temperature-typed mineral insulated cables

Nakano, Hiroko; Uehara, Toshiaki; Takeuchi, Tomoaki; Shibata, Hiroshi; Nakamura, Jinichi; Matsui, Yoshinori; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English

Oral presentation

Analysis of medium-mediated bystander effects induced by carbon-ion irradiation between human lung normal and cancer cells

Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kanai, Tatsuaki*; Nakano, Takashi*; Kobayashi, Yasuhiko

no journal, , 

In this study, human lung normal fibroblasts WI-38 and human lung cancer cells H1299/wt${it p53}$ were used. Cells were irradiated with carbon-ion broad beams, then survival rates of bystander cells after co-culture with irradiated cells were measured using colony assay. The survival rates of non-irradiated bystander cancer cells co-cultured with 0.13 Gy irradiated normal cells increased after 6-hours co-culture. On the other hand, the bystander cells co-cultured with 0.5 Gy irradiated normal cells showed decreased survival rates. These results indicated that the bystander responses of the cancer cells changes according to the irradiation dose on the normal cells. In addition, the survival rates of bystander cancer cells showed a tendency to increase by the addition of Carboxy-PTIO to the co-culture medium, when co-cultured with 0.5 Gy irradiated normal cells. From these results, reduction of survival rates is likely to be caused by NO radical as a mediator in bystander effects.

Oral presentation

Patterning irradiation for contact co-culture of different type cells using heavy-ion microbeam

Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kanai, Tatsuaki*; Nakano, Takashi*; Kobayashi, Yasuhiko

no journal, , 

There have been some reports on bystander effects induced by proton microbeam in contact co-cultured different type cells, but there are few reports using heavy-ion microbeam. So, we have established a new contact co-culture system between human lung normal fibroblast cell line WI-38 and human lung cancer cell line H1299/wt${it p53}$ in the same dish. We have also adapted patterning irradiation systems which automatically irradiated to cancer cells (or normal cells) in a certain range by making use of the target cell irradiation technique at JAEA-Takasaki. Thereby, we were able to successively irradiate to 250 sites of confluent cancer area (lengthwise: 5 mm) so as not to overlap the irradiated range, using carbon-ion microbeam collimated by aperture of $$Phi$$20 $$mu$$m. Now, we are analyzing DNA damage and repair of patterning irradiation samples by evaluating focus numbers of immunostained 53BP1 and $$gamma$$-H2AX. The details of the method and findings will be reported in the talk.

Oral presentation

Development for high-performance irradiation tests and PIE techniques with research/testing reactors

Tsuchiya, Kunihiko; Takeuchi, Tomoaki; Otsuka, Noriaki; Shibata, Hiroshi; Nakano, Hiroko; Ishida, Takuya; Uehara, Toshiaki; Yamamoto, Keiichi; Saito, Takashi; Nakamura, Jinichi; et al.

no journal, , 

no abstracts in English

Oral presentation

Development of radiation resistant in-water transmission system using visible light with environmental robustness

Takeuchi, Tomoaki; Otsuka, Noriaki; Nakano, Hiroko; Shibagaki, Taro*; Komanome, Hirohisa*; Tsuchiya, Kunihiko

no journal, , 

Considering that reactor buildings could be filled with water under severe accidents, a development of the wireless transmission system in water is necessary. In this study, transmission method using visible light was adopted because of its relatively lower attenuation rate and higher transmission rate in water. In the designed transmission system, two-dimensional transmission devices were adopted. LEDs arranged in a two-dimensional array and a camera using a CMOS image sensor, that is like a 2D aggregation of PDs, were used as the light emission and receiving devices, respectively. Moreover, both of pattern and flicker signals can be simultaneously emitted. To confirm the environmental robustness, the in-water transmission tests using the two-dimensional transmission devices were performed with and without air bubbles. The results indicated the pattern signals were more easily influenced than the flicker signals by the air bubbles. In addition, surface mounting LEDs were more suitable than bullet-type LEDs because of their good distinctiveness of the light spots from each LED. On the other hand, $$gamma$$ irradiation tests for the LEDs were performed. The results again indicated surface mounting LEDs were advantageous because the decrease rates of the total luminous flux with absorbed $$gamma$$ dose were lower than that of the bullet-type LEDs.

Oral presentation

Corrosion property of sheath materials using MI cables at conditions simulated severe accident

Nakano, Hiroko; Shibata, Hiroshi; Takeuchi, Tomoaki; Matsui, Yoshinori; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English

Oral presentation

Corrosion estimation of sheath materials using signal cables under light water reactor severe accident environment

Nakano, Hiroko; Shibata, Hiroshi; Takeuchi, Tomoaki; Matsui, Yoshinori; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English

Oral presentation

Development of dissolved hydrogen concentration control device

Nakano, Hiroko; Tsuguchi, Akira*; Nakamura, Mutsumi*; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English

35 (Records 1-20 displayed on this page)