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JAEA Reports

Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal year 2020

Ishimaru, Tsuneari; Ogata, Nobuhisa; Kokubu, Yoko; Shimada, Koji; Niwa, Masakazu; Shimada, Akiomi; Watanabe, Takahiro; Sueoka, Shigeru; Yokoyama, Tatsunori; Fujita, Natsuko; et al.

JAEA-Research 2021-007, 65 Pages, 2021/10

JAEA-Research-2021-007.pdf:4.21MB

This annual report documents the progress of research and development (R&D) in the 6th fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. The current status of R&D activities with previous scientific and technological progress is summarized.

JAEA Reports

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific program for fiscal year 2021)

Ishimaru, Tsuneari; Kokubu, Yoko; Shimada, Koji; Shimada, Akiomi; Niwa, Masakazu; Watanabe, Takahiro; Sueoka, Shigeru; Yokoyama, Tatsunori; Fujita, Natsuko; Ogita, Yasuhiro; et al.

JAEA-Review 2021-012, 48 Pages, 2021/08

JAEA-Review-2021-012.pdf:1.64MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2021. The objectives and contents in fiscal year 2021 are described in detail based on the JAEA 3rd Medium- and Long-term Plan (fiscal years 2015-2021). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

JAEA Reports

Interim activity status report of "the group for investigation of reasonable safety assurance based on graded approach" (from September, 2019 to September, 2020)

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

JAEA-Review-2020-056.pdf:3.26MB

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.

Journal Articles

Neutron reflectometry tomography for imaging and depth structure analysis of thin films with in-plane inhomogeneity

Aoki, Hiroyuki; Ogawa, Hiroki*; Takenaka, Mikihito*

Langmuir, 37(1), p.196 - 203, 2021/01

 Times Cited Count:0 Percentile:0(Chemistry, Multidisciplinary)

JAEA Reports

Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal year 2018

Ishimaru, Tsuneari; Ogata, Nobuhisa; Hanamuro, Takahiro; Shimada, Akiomi; Kokubu, Yoko; Asamori, Koichi; Niwa, Masakazu; Shimada, Koji; Watanabe, Takahiro; Saiga, Atsushi; et al.

JAEA-Research 2019-006, 66 Pages, 2019/11

JAEA-Research-2019-006.pdf:4.39MB

This annual report documents the progress of research and development (R&D) in the 4th fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. In this report, the current status of R&D activities with previous scientific and technological progress is summarized.

JAEA Reports

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific program for fiscal year 2019)

Ishimaru, Tsuneari; Ogata, Nobuhisa; Hanamuro, Takahiro; Shimada, Akiomi; Kokubu, Yoko; Asamori, Koichi; Niwa, Masakazu; Shimada, Koji; Watanabe, Takahiro; Sueoka, Shigeru; et al.

JAEA-Review 2019-010, 46 Pages, 2019/09

JAEA-Review-2019-010.pdf:2.45MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency, in fiscal year 2019. The objectives and contents in fiscal year 2019 are described in detail based on the outline of 7 years plan (fiscal years 2015-2021). Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

Journal Articles

The Surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.

Science, 364(6437), p.272 - 275, 2019/04

 Times Cited Count:140 Percentile:99.81(Multidisciplinary Sciences)

The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.

JAEA Reports

Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal year 2017

Ishimaru, Tsuneari; Ogata, Nobuhisa; Shimada, Akiomi; Asamori, Koichi; Kokubu, Yoko; Niwa, Masakazu; Watanabe, Takahiro; Saiga, Atsushi; Sueoka, Shigeru; Komatsu, Tetsuya; et al.

JAEA-Research 2018-015, 89 Pages, 2019/03

JAEA-Research-2018-015.pdf:14.43MB

This annual report documents the progress of research and development (R&D) in the 3rd fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. In this report, the current status of R&D activities with previous scientific and technological progress is summarized.

JAEA Reports

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific Program for fiscal year 2018)

Ishimaru, Tsuneari; Ogata, Nobuhisa; Shimada, Akiomi; Asamori, Koichi; Kokubu, Yoko; Niwa, Masakazu; Watanabe, Takahiro; Saiga, Atsushi; Sueoka, Shigeru; Komatsu, Tetsuya; et al.

JAEA-Review 2018-020, 46 Pages, 2019/01

JAEA-Review-2018-020.pdf:1.25MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency, in fiscal year 2018. The objectives and contents in fiscal year 2018 are described in detail based on the outline of 7 years plan (fiscal years 2015-2021). Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

JAEA Reports

Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal year 2016

Ishimaru, Tsuneari; Yasue, Kenichi*; Asamori, Koichi; Kokubu, Yoko; Niwa, Masakazu; Watanabe, Takahiro; Yokoyama, Tatsunori; Fujita, Natsuko; Saiga, Atsushi; Shimizu, Mayuko; et al.

JAEA-Research 2018-008, 83 Pages, 2018/12

JAEA-Research-2018-008.pdf:11.43MB

This annual report documents the progress of research and development (R&D) in the 2nd fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. In this paper, the current status of R&D activities with previous scientific and technological progress is summarized.

Journal Articles

TEF beam window design and evaluation of structural integrity

Obayashi, Hironari; Takei, Hayanori; Wan, T.; Kogawa, Hiroyuki; Iwamoto, Hiroki; Sasa, Toshinobu

JPS Conference Proceedings (Internet), 8, p.041002_1 - 041002_7, 2015/09

Journal Articles

Mesoscopic structures of vermiculite and weathered biotite clays in suspension with and without cesium ions

Motokawa, Ryuhei; Endo, Hitoshi*; Yokoyama, Shingo*; Ogawa, Hiroki*; Kobayashi, Toru; Suzuki, Shinichi; Yaita, Tsuyoshi

Langmuir, 30(50), p.15127 - 15134, 2014/12

 Times Cited Count:21 Percentile:62.52(Chemistry, Multidisciplinary)

Journal Articles

Monopole-driven shell evolution below the doubly magic nucleus $$^{132}$$Sn explored with the long-lived isomer in $$^{126}$$Pd

Watanabe, H.*; Lorusso, G.*; Nishimura, Shunji*; Otsuka, T.*; Ogawa, K.*; Xu, Z. Y.*; Sumikama, Toshiyuki*; S$"o$derstr$"o$m, P.-A.*; Doornenbal, P.*; Li, Z.*; et al.

Physical Review Letters, 113(4), p.042502_1 - 042502_6, 2014/07

 Times Cited Count:21 Percentile:78.3(Physics, Multidisciplinary)

Journal Articles

Study on the structural integrity of beam window for TEF target

Takei, Hayanori; Obayashi, Hironari; Iwamoto, Hiroki; Kogawa, Hiroyuki; Sasa, Toshinobu

Proceedings of 11th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '13), p.311 - 316, 2014/05

The objective of this study is to evaluate the feasibility of a designed beam window of TEF target by the numerical analysis with a 3D model. The analysis was performed by considering (1) the peak current density and shape of the incident beam, (2) the thermal-fluid behaviour of LBE around the beam window as a function of the flow rate and inlet temperature, (3) the material and the thickness of the beam window, (4) the structural strength of the beam window. In the reference case, the peak current density and the profile of the proton beam were 20 $$mu$$A/cm$$^{2}$$ and a Gaussian shape, respectively. The flow rate of LBE and temperature at the inlet were 1 $$ell/sec$$ and 350 $$^{circ}$$C. The material of a beam window was type SUS316 stainless steel with the 2 mm thick. In this reference case, the maximum velocity of LBE and the maximum temperature located at the top of the beam window were about 1.2 m/sec and 477 $$^{circ}$$C. By increasing the flow rate of LBE up to 4 $$ell/sec$$, the maximum temperature of a beam window was reduced around 420 $$^{circ}$$C. The maximum tresca stress was 190 MPa, which was observed at the center on the outside surface of a beam window. The analyzed stress in the reference case was lower than the tolerance level of the stress strength of the material, and hence the feasibility of a designed beam window was confirmed.

Journal Articles

Green hydrogen production by using nuclear energy for hydrogen steelmaking

Ogawa, Masuro; Kasahara, Seiji; Inagaki, Yoshiyuki; Noguchi, Hiroki

"Gurin Enerugi Seitetsu Kenkyukai" Seika Hokokusho, p.4 - 44, 2012/03

Green hydrogen production by using nuclear energy for hydrogen steelmaking is one of the candidates of CO$$_{2}$$ emission reduction. Very high temperature reactor (VHTR) is the most appropriate reactor type among generation IV nuclear reactors. In Japan, a large-scale national R&D project for nuclear steelmaking had been carried out during 1973-1980. The process was: reforming of bottom residue of oil distillation using nuclear heat to produce reducing gas: direct reduction of ore to produce iron by the reforming gas. R&D of 6 themes had been conducted: total systems, high temperature heat exchangers, very high temperature resistant alloy, high temperature thermal insulation materials, reforming gas generators, and shaft furnaces to produce direct reduced iron. A new type nuclear steelmaking is proposed now by the requirement of technology and a new problem of CO$$_{2}$$ reduction. The largest change is the shift of reducing gas to hydrogen. R&D of VHTR continues since the national project and thermochemical water splitting IS (iodine-sulfur) process has been studied for hydrogen production in Japan Atomic Energy Agency. Conceptual design of a hydrogen steelmaking process applying VHTR-IS process and direct reduction steelmaking with hydrogen had been carried out in Green Energy Steelmaking Research Group in Iron and Steel Institute of Japan during 2008-2012.

Journal Articles

Microscopic structures of tri-$$n$$-butyl phosphate/$$n$$-octane mixtures by X-ray and neutron scattering in a wide $$q$$ range

Motokawa, Ryuhei; Suzuki, Shinichi; Ogawa, Hiroki*; Antonio, M. R.*; Yaita, Tsuyoshi

Journal of Physical Chemistry B, 116(4), p.1319 - 1327, 2012/02

 Times Cited Count:30 Percentile:64.57(Chemistry, Physical)

Journal Articles

Evaluation of nuclear characteristics of light-water-moderated heterogeneous cores in modified STACY

Izawa, Kazuhiko; Aoyama, Yasuo; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi; Miyoshi, Yoshinori

Proceedings of 9th International Conference on Nuclear Criticality (ICNC 2011) (CD-ROM), 11 Pages, 2012/02

For reactor physics and criticality safety researches, the Static Experiment Critical Facility (STACY) will be modified. In the modification, the present STACY, solution-fuel-type homogeneous cores, will be converted to fuel-pin-type heterogeneous cores moderated by light water. For nuclear safety design of the modified STACY, computational analyses have been carried out by using a Monte Carlo code MVP and a transport code system DANTSYS with cross-section data based on the JENDL-3.3. In the analyses, basic nuclear characteristics have been evaluated, such as criticality, water-level worth and reactor shutdown margin. By the results of these analyses, the feasibility of reactivity control mechanism and the sufficiency of reactor shutdown margin of the modified STACY were confirmed. In addition, temperature and void coefficients of reactivity and kinetic parameters were obtained to comprehend nuclear characteristics of the modified STACY.

Journal Articles

Application of thermochemical hydrogen production iodine-sulfur process to shaft furnace direct reduction ironmaking process

Kasahara, Seiji; Kubo, Shinji; Noguchi, Hiroki; Ohashi, Hirofumi; Ogawa, Masuro

Proceedings of International Symposium on Ironmaking for Sustainable Development 2010, p.84 - 87, 2010/01

Iodine-sulfur process (IS process) is a hydrogen production process from water by using heat around 900 $$^{circ}$$C without CO$$_{2}$$ production. An ironmaking plant combining IS process and hydrogen direct reduction shaft furnace is proposed. Heat/mass balance analysis of the plant was carried out by flowsheet calculation. Comparison of the process with a conventional blast furnace plant and a direct reduction process using reformed natural gas was carried out. Though total heat input to the process was greatest in these plants, CO$$_{2}$$ production of the hydrogen plant was 8 % of the blast furnace plant.

Journal Articles

A Preliminary comprehensive dynamic analysis of the typical FaCT scenarios with JSFR and related fuel cycle facilities

Shiotani, Hiroki; Ono, Kiyoshi; Ogawa, Takashi; Koma, Yoshikazu; Kawaguchi, Koichi

Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9419_1 - 9419_10, 2009/05

Dynamic analyses of the typical FR deployment scenarios with JSFR and related fuel cycle facilities developed in FaCT project was conducted. The total cash out-flows and the average electricity generation costs to 22nd century were calculated to seize the long-term economics as well as the material compositions in the nuclear facilities, the quantities of radioactive wastes generations. Several cash out-flow peaks and radioactive waste generation peaks were found because of the decommissioning and construction of the nuclear power plants and reprocessing plants for LWR spent fuel. Then, different breeding ratio, single/dual-purpose reprocessing plant, and with/without Am-Cm recycling were compared. For example, the exploration of the optimal breeding ratio between B.R. =1.1 and 1.2 for the start up stage FR was considered to be reasonable from the analysis.

Journal Articles

Temperature-dependent nano-scale dynamics of PVA physical gel

Takahashi, Nobuaki; Nishida, Koji*; Inoue, Rintaro*; Ogawa, Hiroki*; Kanaya, Toshiji*; Nagao, Michihiro*

NSL News Letter, 2007-4, p.155 - 157, 2007/04

We have studied dynamics of poly(vinyl alcohol) (PVA) gel in a mixture of deuterated dimethyl sulfoxide (DMSO-d$$_{6}$$) and D$$_{2}$$O (60/40 by volume) during heating process from 25$$^{circ}$$C to 80$$^{circ}$$C using neutron spin-echo (NSE) techniques.

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