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JAEA Reports

Laboratory testing of rock core samples from pre-excavation grouting area at Mizunami Underground Research Laboratory

Uyama, Masao*; Hitomi, Takashi*; Nakashima, Satoru*; Sato, Toshinori; Sanada, Hiroyuki; Aoyagi, Yoshiaki

JAEA-Research 2015-010, 67 Pages, 2015/10

JAEA-Research-2015-010.pdf:32.34MB
JAEA-Research-2015-010-appendix(CD-ROM).zip:528.25MB

Japan Atomic Energy Agency has been conducting a research project on (Grouting Technology Development for the Radioactive Waste Repository) funded by Ministry of Economy, Trade and Industry (METI), Japan. As a part of the project, various investigations were carried out in the -200m Refuge Niche where pre-excavation grouting was performed and the distribution of the injected grouting material, also the effectiveness of grouting penetration for reduction of groundwater inflow were confirmed As the continuation of these investigations, chemical influences of grouting material on the rock mass were determined through (Laboratory testing of rock core samples from pre-excavation grouting area at Mizunami Underground Research Laboratory). Specifically, core samples were obtained by check boring at where infiltration solidification of the grouting material was expected, and X-ray florescent analysis and Transmission Electron Microscope observation were performed focused on the contact parts of the grouting material and rock mass in fractures. As a result, the chemical influences of grouting material on the rock mass were identified.

Journal Articles

Characteristics of beta reference radiation fields at the Facility of Radiation Standards (FRS), JAEA for their practical applications in beta dosimetry

Yoshitomi, Hiroshi; Kowatari, Munehiko; Suzuki, Takashi

Proceedings of 4th Asian and Oceanic Congress on Radiation Protection (AOCRP-4) (CD-ROM), 4 Pages, 2015/07

The Facility of Radiation Standards (FRS) in the Japan Atomic Energy Agency (JAEA) provides beta-ray calibration fields for the customers to calibrate dosemeters. Two different types of beta-ray irradiation systems, so called BSS2 and JBS, have been installed and operated in the FRS. They have quite different types of the beta-ray radiation sources, which might be attributed to variations in dosimetric quantities. Variations in these quantities would affect the calibration factor of a dosemeter. A comparison of dosimetric quantities for beta reference radiation fields of both beta-ray irradiation systems was made, in order to investigate how these quantities differ between them and how much differences affect calibration results. With regard to the depth dose curve which is one of the key dosimetric quantities, it was found that they showed different profiles between both systems reflecting their characteristics. This implies that the difference between two systems might affect the calibration of dosemeters, especially one with more than 400 mg/cm$$^2$$ thickness or one made of high-Z materials for $$^{90}$$Sr/$$^{90}$$Y field.

Journal Articles

Investigation methodology for influence of cement material from grouting origin to granite

Uyama, Masao*; Hitomi, Takashi*; Sato, Toshinori

Doboku Gakkai Heisei-25-Nendo Zenkoku Taikai Dai-68-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), 2 Pages, 2013/09

no abstracts in English

Journal Articles

Observation of granite influenced by cement material from grouting origin

Hitomi, Takashi*; Uyama, Masao*; Sato, Toshinori

Doboku Gakkai Heisei-25-Nendo Zenkoku Taikai Dai-68-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), 2 Pages, 2013/09

no abstracts in English

Journal Articles

Study on long-term leaching behavior of low alkaline cement

Hitomi, Takashi*; Iriya, Keishiro*; Nakayama, Masashi; Sato, Haruo

Proceedings of 3rd International Conference on Sustainable Construction Materials & Technologies (SCMT-3) (Internet), p.e0179_1 - e0179_9, 2013/08

Leaching procedure is studied on Low alkaline cement in which pozzolanic reaction is used for decreasing pH of pore water of cement hydrate to avoid influence on rock and other materials. Leached depth of Low alkaline cement (HFSC) by the immersion examination with Horonobe simulated ground was smaller than depth of ion-exchanged water. Water exchanging is smaller than that of Ordinary Poltland Cement (OPC) with the same water binder ratio, since soluble Portlandite was not produced and dissoluble Calcium Silicate components were mainly produced. Although simulated groundwater in Horonobe URL was used for immersion examination, the low alkaline cement hydrates is more durable for leaching degradation than OPC. For all cements, groundwater showed tendency of accelerate leaching compared to ion exchanged water. This study shows that HFSC has higher durability for leaching degradation to groundwater than OPC.

Journal Articles

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

JAEA Reports

Study on applicability of low alkaline cement in Horonobe Underground Research Laboratory Project, 3 (Contract research)

Nakayama, Masashi; Kobayashi, Yasushi; Noguchi, Akira; Miura, Norihiko*; Noda, Masaru*; Iriya, Keishiro*; Hitomi, Takashi*

JAEA-Research 2009-036, 49 Pages, 2009/11

JAEA-Research-2009-036.pdf:20.34MB

In Horonobe Underground Research Laboratory (Horonobe URL) Project, construction practicality test with HFSC (Highly Fly-ash contained Silica-fume Cement) is planned in a part of the gallery. It is necessary to validate that HFSC has performance under the actual construction, before HFSC is placed in the gallery. The main tasks in 2008 are follows; (1) suggestion of mix design for liner concrete of shaft in Horonobe URL, (2) investigation of long term pH changes in order to use for modeling, and (3) an experiment for interaction between HFSC and ground water around Horonobe URL. (1) 4 types of mix proportion are designed for ordinary concrete and high strength concrete which contains polypropylene fiber or not. As early age strength, 5N/mm$$^{2}$$ is required because of concrete formwork. HFSC424 with low water binder ratio can fulfill this requirement in combination with super plasticizer. (2) pH and components of solid and liquid phase which were made in 2003, and stored in water were analyzed. And cement paste of shotcrete which are made in 2006 were also analyzed. In this pH of shotcrete is lower than other in situ concrete since accelerating agent may act as decreasing factor of pH. (3) An experiment which investigates dissolution of HFSC cement hydrates to ground water around Horonobe URL. According to the experiment, dissolving depth of HFSC is 4 times small comparing to Ordinary Portland Cement hydrates after 30th water exchange.

Journal Articles

Progress in R&D efforts on the energy recovery linac in Japan

Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06

Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.

Journal Articles

Prediction of crack due to corrosion of reinforcing bar in low alkali concrete

Takeda, Nobufumi*; Iriya, Keishiro*; Hitomi, Takashi*; Konishi, Kazuhiro*; Kurihara, Yuji*

Obayashigumi Gijutsu Kenkyushoho (CD-ROM), (72), 8 Pages, 2008/00

To evaluate applicability as the steel reinforced concrete of the concrete with the low alkalinity cement which contains pozzolan that has been examined to apply for high level radioactive waste disposals, concrete of 30% water-cement ratio was performed 6-year marine exposure examination, aging of their compressive strength, the intrusion width of the chloride ion and the corrosion of reinforcing bar were investigated. And based on these results, progress of corrosion of reinforcing bar and the outbreak time of reinforcing corrosion crack were predicted. As a result, the following result became clear. (1) There is no fall of the compressive strength of test pieces in 6-year marine exposure examination. (2) There is little penetration of the chloride ion in comparison with the concrete consists of ordinary Portland cement. (3) The corrosion of reinforcing bar starts for the early stage with a little quantity of chloride ion intrusion, the progress until six years is extremely small. (4) the corrosion speed of the reinforcing bar of concrete with low alkali cement in underground water including sea water were estimated as 0.30$$sim$$0.55 mg/(cm$$^{2}$$ year). In case of using this concrete to structure with 100 mm cover thickness and 22 mm reinforcing bar diameter, the outbreak time of reinforcing corrosion crack were predicted as 50$$sim$$100 years after construction.

Journal Articles

Diagnostics system of JT-60U

Sugie, Tatsuo; Hatae, Takaki; Koide, Yoshihiko; Fujita, Takaaki; Kusama, Yoshinori; Nishitani, Takeo; Isayama, Akihiko; Sato, Masayasu; Shinohara, Koji; Asakura, Nobuyuki; et al.

Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.482 - 511, 2002/09

 Times Cited Count:6 Percentile:96.97(Nuclear Science & Technology)

The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so that the internal structure of plasmas has been explored. The understanding of plasma confinement has been enhanced by density and temperature fluctuation measurements using a mm-wave reflectometer and electron cyclotron emission measurements respectively. In addition, the real-time control experiments of electron density, neutron yield, radiated power and electron temperature gradient have been carried out successfully by corresponding diagnostic devices. These measurements and the real time control contribute to improving plasma performance. Diagnostic devices for next generation fusion devices such as a CO2 laser interferometer/polarimeter and a CO2 laser collective Thomson scattering system have been developed.

JAEA Reports

The First loading fuel elements and power-up for JRR-2

JRR-2 Control Office; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Morozumi, Minoru; Kambayashi, Yuichiro; Shitomi, Hajimu; Kokanezawa, Takashi; et al.

JAERI 1027, 57 Pages, 1962/09

JAERI-1027.pdf:4.76MB

no abstracts in English

JAEA Reports

Efficiency testing of the control and cooling systems of JRR-2

Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Haginoya, Kinichi; Kohayakawa, Toru; Yamaki, Jikei; Yokota, Mitsuo; Horiki, Oichiro; Yuhara, Shunichi; et al.

JAERI 1023, 120 Pages, 1962/09

JAERI-1023.pdf:8.67MB

no abstracts in English

JAEA Reports

Treatment and analysis of the water and gas in JRR-2

JRR-2 Operations Office; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Haginoya, Kinichi; Kohayakawa, Toru; Yamaki, Jikei; Yokota, Mitsuo; Horiki, Oichiro; et al.

JAERI 1024, 79 Pages, 1962/08

JAERI-1024.pdf:5.66MB

no abstracts in English

JAEA Reports

Critical experiments and characteristic measurement for JRR-2

JRR-2 Critical Experiments Group; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Morozumi, Minoru; Kambayashi, Yuichiro; Shitomi, Hajimu; Kokanezawa, Takashi; et al.

JAERI 1025, 62 Pages, 1962/03

JAERI-1025.pdf:4.6MB

no abstracts in English

Oral presentation

Investigation of leaching behavior of low alkaline cement in Horonobe underground water environment

Hitomi, Takashi*; Iriya, Keishiro*; Nakayama, Masashi

no journal, , 

In JAEA, HFSC (Highly Fly ash contained Silica-fume Cement) in which the calcium hydroxide of cement become pozzolana is developed. Dipping test with the solution which simulated groundwater environment of Horonobe was performed, and HFSC was shown as having high leaching resistance in comparison with OPC. In addition, whereas an invasion of chloride ion was seen in the whole of the sample in the OPC, in HFSC, an invasion was seen in only the part of leached area.

Oral presentation

A Method of dead time measurement utilizing swipe sample inside hot cell

Iwasa, Atsutoshi; Nakayama, Naoto; Mikami, Satoshi; Eguchi, Kazutoshi; Takashima, Hideki; Hitomi, Junichi; Gomibuchi, Masaru*

no journal, , 

no abstracts in English

Oral presentation

Influence and countermeasure of introduction of surface contamination evaluation method based on JIS

Ishida, Keiichi; Mikami, Satoshi; Iwasa, Atsutoshi; Hamazaki, Masaaki; Usui, Toshihide; Takashima, Hideki; Hitomi, Junichi

no journal, , 

no abstracts in English

Oral presentation

Development of the server system for Personal Dose Management

Miyauchi, Hideaki; Yoshitomi, Hiroshi; Akazaki, Tomohiko; Tachibana, Haruo; Suzuki, Takashi

no journal, , 

In the Nuclear Science Research Institute in the Japan Atomic Energy Agency (JAEA), the registration management of exposure dose data for radiation workers has been carried out using the "Personal dose Management System" that is took over from the old Japan Atomic Energy Research Institute. In accordance with the result of the discussion which of unification of a radiation control system, or rationalization in JAEA, development of the server system for Personal Dose Management was gradually advanced from 2006, all functions were ready in 2010, and the server system started formal operation in 2011. By the development of the server system, work efficiency and the accuracy of data improved, and more precise management of exposure dose was enabled.

Oral presentation

Personal monitoring for assistance staff to Fukushima

Suzuki, Takehiko; Murayama, Takashi; Miyauchi, Hideaki; Sato, Yoshitaka; Oi, Yoshihiro; Tachibana, Haruo; Yoshitomi, Hiroshi

no journal, , 

Nuclear Science Research Institute is assisting activities concerning the accident of the Fukushima No.1 Nuclear Power Station including the environmental monitoring and the resident's house decontamination, etc. In these assistance, we executing the personal monitoring to assistance staff, because there was fear of the external exposure and the internal exposure. We did by the measurement and the evaluation method of the personal monitoring in consideration of the rise of the environmental background level. We introduce the method of use to evaluate the exposed dose etc.

Oral presentation

Temporal facility radiation control activities in JAEA research reactor plants under ascended radiation levels due to the accident of Fukushima Daiichi Nuclear Plants

Irokawa, Hiroyuki; Hamazaki, Masaaki; Ishida, Keiichi; Miura, Yoshiyuki; Iwasa, Atsutoshi; Kano, Yutaka; Mikami, Satoshi; Takashima, Hideki; Hitomi, Junichi

no journal, , 

no abstracts in English

32 (Records 1-20 displayed on this page)