Interlaboratory comparison of electron paramagnetic resonance tooth enamel dosimetry with investigations of the dose responses of the standard samples

Toyoda, Shin*; Inoue, Kazuhiko*; Yamaguchi, Ichiro*; Hoshi, Masaharu*; Hirota, Seiko*; Oka, Toshitaka; Shimazaki, Tatsuya*; Mizuno, Hideyuki*; Tani, Atsushi*; Yasuda, Hiroshi*; et al.

Radiation Protection Dosimetry, 199(14), p.1557 - 1564, 2023/09

https://doi.org/10.1093/rpd/ncad150

Interlaboratory comparison studies are important for radiation dosimetry in order to demonstrate how the technique is universally available. The set of standard samples are examined in each participating laboratory in the present study. After a set of standard samples together with the samples with unknown doses, which were prepared in the same laboratory as the standard samples, are measured at a participating laboratory, those samples are sent to another participating laboratory for next measurement. There is some small difference observed in the sensitivity (the slope of the dose response line) of the standard samples while the differences in the obtained doses for the samples with unknown doses are rather systematic, implying that the difference is mostly due to the samples but not to measurements.

Development plan for coupling technology between high temperature gas-cooled reactor HTTR and hydrogen production facility, 1; Overview of the HTTR heat application test plan to establish high safety coupling technology

Nomoto, Yasunobu; Mizuta, Naoki; Morita, Keisuke; Aoki, Takeshi; Okita, Shoichiro; Ishii, Katsunori; Kurahayashi, Kaoru; Yasuda, Takanori; Tanaka, Masato; Isaka, Kazuyoshi; et al.

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 7 Pages, 2023/05

Atmospheric resuspension of insoluble radioactive cesium bearing particles found in the difficult-to-return area in Fukushima

Tang, P.*; Kita, Kazuyuki*; Igarashi, Yasuhito*; Satou, Yukihiko; Hatanaka, Kotaro*; Adachi, Koji*; Kinase, Takeshi*; Ninomiya, Kazuhiko*; Shinohara, Atsushi*

Progress in Earth and Planetary Science (Internet), 9(1), p.17_1 - 17_15, 2022/03

https://doi.org/10.1186/s40645-022-00475-6

High spatial resolution neutron transmission imaging using a superconducting two-dimensional detector

Shishido, Hiroaki*; Nishimura, Kazuma*; Vu, TheDang*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; et al.

IEEE Transactions on Applied Superconductivity, 31(9), p.2400505_1 - 2400505_5, 2021/12

https://doi.org/10.1109/TASC.2021.3111396

In this study, we employed a superconducting detector, current-biased kinetic-inductance detector (CB-KID) for neutron imaging using a pulsed neutron source. We employed the delay-line method, and high spatial resolution imaging with only four reading channels was achieved. We also performed wavelength-resolved neutron imaging by the time-of-flight method. We obtained the neutron transmission images of a Gd-Al alloy sample, inside which single crystals of GdAl were grown, using the delay-line CB-KID. Single crystals were well imaged, in both shapes and distributions, throughout the Al-Gd alloy. We identified Gd nuclei via neutron transmissions that exhibited characteristic suppression above the neutron wavelength of 0.03 nm. In addition, the Gd resonance dip, a dip structure of the transmission caused by the nuclear reaction between an isotope and neutrons, was observed even when the number of events was summed over a limited area of 15 m 12 m. Gd selective imaging was performed using the resonance dip of Gd, and it showed clear Gd distribution even with a limited neutron wavelength range of 1 pm.

High temperature gas-cooled reactors

Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.

High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02

https://doi.org/10.1016/C2018-0-05383-9

As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.

Development on laser cutting technique to suppress spatter particles aiming at disposal of radio-active waste

Naoe, Takashi; Teshigawara, Makoto; Futakawa, Masatoshi; Mizutani, Haruki; Muramatsu, Toshiharu; Yamada, Tomonori; Ushitsuka, Yuji*; Tanaka, Nobuatsu*; Yamasaki, Kazuhiko*

Proceedings of 8th International Congress on Laser Advanced Materials Processing (LAMP 2019) (Internet), 5 Pages, 2019/05

Laser cutting is one of the options in the disposal of radio-active waste, such as spallation neutron target vessel in J-PARC, etc. Due to unique characteristic of laser, such as non-contact system, it is more easily to provide remote-controlled system in comparison with conventional one, such as mechanical cutting machine, etc. However, a demerit of laser cutting is the sputter and fume caused by laser cutting, resulting in contamination with radio-active materials its surroundings. Recently it was developed that the spatter suppression technique by controlling laser beam profile in laser welding process. In order to apply this suppression technique to laser cutting, first of all, we attempted to observe the phenomenon at melting area during laser cutting using a high-speed video camera in order to make the physical model. The result showed that the appearance of fume and sputter were independently confirmed in the time evolution.

Retreat from stress; Rattling in a planar coordination

Suekuni, Koichiro*; Lee, C. H.*; Tanaka, Hiromi*; Nishibori, Eiji*; Nakamura, Atsushi*; Kasai, Hidetaka*; Mori, Hitoshi*; Usui, Hidetomo*; Ochi, Masayuki*; Hasegawa, Takumi*; et al.

Advanced Materials, 30(13), p.1706230_1 - 1706230_6, 2018/03

https://doi.org/10.1002/adma.201706230

Thermoelectric materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. In this paper, we studied the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)(Sb,As)S. The results revealed that the Cu atoms in a planar coordination are rattling, which effectively scatter phonons. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination.

Recent progress in the chopper spectrometer 4SEASONS at J-PARC

Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Nakajima, Kenji; Kawamura, Seiko; Nakatani, Takeshi; et al.

JAEA-Conf 2015-002, p.319 - 329, 2016/02

https://doi.org/10.11484/jaea-conf-2015-002

Study of receptivity of wastes in natural environment (Joint research)

Tanaka, Masaru*; Gofuku, Akio*; Ishizaka, Kaoru*; Sato, Kazuhiko; Nagahama, Yoji

JAEA-Research 2014-019, 103 Pages, 2014/12

JAEA-Research-2014-019.pdf:12.1MB

We had been conducting a research on risk perception and confidence-building among stakeholders regarding environmental remediation of Uranium mine site and disposal of industrial waste from FY 2007. FY 2011, we study how the Great East Japan Earthquake and Fukushima nuclear accident affects public risk perception. Therefore, a questionnaire survey on public risk perception of environmental remediation of Uranium mine site and disposal of the industrial waste in Okayama prefecture had been carried out. Another questionnaire survey on public risk perception of the disposal of disaster waste for residents in Okayama prefecture has been carried out. Following are some of the results: (1) For risk perception regarding environmental remediation of Uranium mine site, "knowledge of radiation" and "Concern about radioactive material" and "Information literacy" did not change significantly. Conversely trust in "Public administration" and "facility owner" and "Science and technology" was decreased significantly. (2) For risk perception regarding disaster waste, many people recognize the need for wide area disposal of disaster waste. Conversely, many residents are concerned about radioactive materials.

A Sampling method of oriented small sample from fault cores for SEM observation

Shimada, Koji; Kametaka, Masao*; Nakayama, Kazuhiko; Seshimo, Kazuyoshi; Tanaka, Yoshihiro; Hayashi, Toshio*; Tanaka, Yukumo; Shimogama, Kota*; Okazaki, Kazuhiko*

Chishitsugaku Zasshi, 119(11), p.727 - 731, 2013/11

https://doi.org/10.5575/geosoc.2013.0050

Staples for a stapler can be used as a frame of a small oriented sample taken from fragile and scarce fault gouge. The fault gouge was slotted for staples of an insert. Staples are a group of about ten or less ones holding right-angled three small surfaces. Pre-oriented staples set the slot would remove then presented for the SEM observation. Only a knife, some glues and simple equipment are needed for the method in the field or laboratories.