Characteristics of fault fracture zones of the activated Shionohira Fault and the non-activated Kuruma Fault of the 2011 Fukushima-ken Hamadori Earthquake, Northeast Japan

Aoki, Kazuhiro; Tanaka, Yukumo; Yoshida, Takumi; Shimada, Koji; Sakai, Toru*; Kametaka, Masao*; Seshimo, Kazuyoshi

Oyo Chishitsu, 62(2), p.64 - 81, 2021/06

Co-seismic surface ruptures in the Fukushima-ken Hamadori Earthquake of Mw 6.7 on April 11, 2011 exposed approximately 14 km trending NNW-SSE from Nameishi to northwest of Ishizumi Tsunaki of Tabito Town, Iwaki City and were newly named the Shionohira Fault. However, no surface ruptures appeared along an N-S trending active Kuruma fault extending 5 km south of the Shionohira Fault. Because of the proximity and similar strike, two locations in Shionohira Fault and one location in Kuruma fault were selected as the study area for the fault activity evaluation. The present study reports the results of a series of geological and drilling surveys, core observation, XRD, isotope, and fluid inclusion analyses, and water permeability test. The results obtained from the three locations offer a fundamental data base that can be utilized for fault activity evaluation by summarizing the geological, mineralogical, and fluid property characteristics of fault fracture zone.

Ion hydration and association in an aqueous calcium chloride solution in the GPa range

Yamaguchi, Toshio*; Nishino, Masaaki*; Yoshida, Koji*; Takumi, Masaharu*; Nagata, Kiyofumi*; Hattori, Takanori

European Journal of Inorganic Chemistry, 2019(8), p.1170 - 1177, 2019/02

https://doi.org/10.1002/ejic.201900016

Neutron diffraction measurements of an aqueous 2 mol dm CaCl solutions in DO have been made at 1 GPa, 298 K as well as 0.1 MPa, 298 K. The experimental structure factors are subjected to Empirical Potential Structure Refinement (EPSR) modeling to reveal the ion hydration and association and solvent water at the atomic level. About seven water molecules surround Ca at the Ca-O and Ca-D distances of 2.44 and 3.70 , respectively, at both pressures, suggesting no significant pressure effect on the cation hydration. On the other hand, the Cl ion shows a drastic change in water oxygen coordination from 7 at 0.1 MPa to 14 at 1 GPa, accompanied by shortening of Cl-O distance from 3.18 to 3.15 . However, the number of water hydrogen atoms around Cl does not change significantly as 6.0 6.7 with shortening Cl-D distance from 2.22 to 2.18 on compression. The pressure effect on the solvent water structure is also drastic as an increase in water oxygen atoms of 4.7 at the O-O distance of 2.79 at 0.1 MPa to 10.3 at 2.85 at 1 GPa. The number of water hydrogen atoms, however, does not change as 1.2 at the O-D distance of 1.74 for both pressures, demonstrating the presence of the OD hydrogen bonds which are significantly bent at 1 GPa at 298 K. This change of hydrogen bonds in water with pressure probably causes the drastic increase in water oxygen atoms around Cl.

Effect of neutron energy and fluence on deuterium retention behaviour in neutron irradiated tungsten

Fujita, Hiroe*; Yuyama, Kenta*; Li, X.*; Hatano, Yuji*; Toyama, Takeshi*; Ota, Masayuki; Ochiai, Kentaro; Yoshida, Naoaki*; Chikada, Takumi*; Oya, Yasuhisa*

Physica Scripta, 2016(T167), p.014068_1 - 014068_5, 2016/02

https://doi.org/10.1088/0031-8949/T167/1/014068

The irradiation defects were introduced by Fe irradiation, fission neutron irradiation and D-T neutron irradiation. After the irradiation, the deuterium ions (D) implantation was performed and the D retention behavior was evaluated by thermal desorption spectroscopy. The experimental results indicated that dense vacancies and voids within the shallow region near the surface were introduced by Fe irradiation. The trapping state of D by vacancies and void were clearly controlled by the damage concentration and the voids would become the most stable D trapping site. For fission neutron irradiated W, most of the D was adsorbed on the surface and/or trapped by dislocation loops and no vacancies and voids for D trapping due to its lower damage concentration. D trapping by vacancies were found in the bulk of D-T neutron irradiated W, indicating that the neutron energy distribution could make a large impact on irradiation defect formation and the D retention behavior.

Measurement performance of the NDA using Q2 system for uranium waste drum

Ohara, Yoshiyuki; Naganuma, Masaki; Nohiro, Tetsuya*; Yoshida, Kimikazu*; Makita, Akinori*; Sakate, Mitsuo*; Irisawa, Takumi*; Murashita, Tatsuya*

JAEA-Technology 2012-048, 39 Pages, 2013/03

JAEA-Technology-2012-048.pdf:5.1MB

In Japan Atomic Energy Agency Ningyo-Toge Environmental Engineering Center, exploration for uranium and technical development of uranium refining, conversion and enrichment which are the front end of a nuclear fuel cycle have been performed since 1955. By these research and development, about 15000 radioactive waste (200 liter drum) has occurred by now. The analytical and measurement technique of the amount of uranium which are included in radioactive waste drum were very an inexperienced in those days. Therefore, measurement strict till 2002 was not able to be started. Such a situation as this, we introduced "Q2 low-level-waste drum measuring system" which is a bulk measuring method of the passive ray using a NaI scintillation detector in 2002. As a result, the total amount of uranium in a waste drum was estimated as about 20 tons.

Conceptual design of the SlimCS fusion DEMO reactor

Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.

JAEA-Research 2010-019, 194 Pages, 2010/08

JAEA-Research-2010-019-01.pdf:48.47MB
JAEA-Research-2010-019-02.pdf:19.4MB

This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.

Status of JT-60SA tokamak under the EU-JA broader approach agreement

Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.

Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12

https://doi.org/10.1016/j.fusengdes.2008.06.047

no abstracts in English

Design of the ITER tritium plant, confinement and detritiation facilities

Yoshida, Hiroshi; Glugla, M.*; Hayashi, Takumi; Lsser, R.*; Murdoch, D.*; Nishi, Masataka; Haange, R.*

Fusion Engineering and Design, 61-62, p.513 - 523, 2002/11

https://doi.org/10.1016/S0920-3796(02)00105-9

ITER tritium plant is composed of tokamak fuel cycle systems, tritium confinement and detritation systems. The tokamak fuel cycle systems, composed of various tritium sumsystems such as vacuum vessel cleaning gas processing, tokamak exhaust processing, hydrogen isotope separation, fuel storage, mixing and delivery, and external tritium receiving and long-term storage, has been designed to meet not only ITER operation scenarios but safety requirements (minimization of equipment tritium inventory and reduction of environmental tritium release at different off-normal events and accident scenarios). Multiple confinement design was employed because tritium easily permeates through metals (at 150 C) and plastics (at ambient temperature) and mixed with moisture in room air. That is, tritium process equipment and piping are designed to be the primary confinement barrier, and the process equipments (tritium inventory 1 g) are surrounded by the secondary confinement barrier such as a glovebox. Tritium process rooms, which contains these facilities, form the tertiary confinement barrier, and equipped with emergency isolation valves in the heating ventillation and air conditioning ducts as well as atmosphere detritiation systems. This confinement approach has been applied to tokamak building, tritium building, and hotcell and radwaste building.

Analysis on tritium permeation in tritium storage bed with gas flowing calorimetry

Nakamura, Hirofumi; Hayashi, Takumi; Suzuki, Takumi; Yoshida, Hiroshi*; Nishi, Masataka

JAERI-Research 2000-044, 24 Pages, 2000/10

JAERI-Research-2000-044.pdf:0.97MB

no abstracts in English

Radiation dose rate mapping around a glove box at a MOX fuel facility

Morishita, Yuki; Sagawa, Naoki; Suga, Takumi; Tsujimura, Norio; Yoshida, Tadayoshi; Nagai, Hiroyuki

no journal, , 

no abstracts in English

Evaluation of dose distribution of an eye lens and a body surface using an anthropomorphic phantom at a MOX fuel facility

Suga, Takumi; Morishita, Yuki; Sagawa, Naoki; Yamazaki, Takumi; Tsujimura, Norio; Yoshida, Tadayoshi; Nagai, Hiroyuki

no journal, , 

no abstracts in English