The Laboratory Operation Based on ISO/IEC 17025; Radioactivity analysis of environmental samples by germanium semiconductor detectors

Urushidate, Tadayuki*; Yoda, Tomoyuki; Otani, Shuichi*; Yamaguchi, Toshio*; Kunii, Nobuaki*; Kuriki, Kazuki*; Fujiwara, Kenso; Niizato, Tadafumi; Kitamura, Akihiro; Iijima, Kazuki

JAEA-Review 2022-023, 8 Pages, 2022/09

JAEA-Review-2022-023.pdf:1.19MB

After the accident of the Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency has newly set up a laboratory in Fukushima and started measuring radioactivity concentrations of environmental samples. In October 2015, Fukushima Radiation Measurement Group has been accredited the ISO/IEC 17025 standard by the Japan Accreditation Board (JAB) as a testing laboratory for radioactivity analysis (Cs, Cs) based on Gamma-ray spectrometry with germanium semiconductor detectors. The laboratory has measured approximately 60,000 of various environmental samples at the end of March 2022. The laboratory quality control and measurement techniques have been accredited by regular surveillance of JAB. In September 2019, the laboratory renewed accreditation as a testing laboratory for radioactivity analysis.

Japanese FR deployment scenario study after the Fukushima accident

Ono, Kiyoshi; Shiotani, Hiroki; Ohtaki, Akira; Mukaida, Kyoko; Abe, Tomoyuki

Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Safe Technologies and Sustainable Scenarios (FR-13) (USB Flash Drive), 10 Pages, 2013/03

http://www.iaea.org/nuclearenergy/nuclearpower/Downloadable/Meetings/2013/2013-03-04-03-07-CF-NPTD/T8.1/T8.1.ono.pdf

In parallel to the mid-term analyses by the AEC after the Fukushima-accident, JAEA implemented the long-term scenario analyses for the nuclear fuel cycle options including FR cycle deployment. As a result, it was revealed that FR cycle deployment brings great benefits to reduction of uranium demand, spent fuel storage, radioactive waste generation, and Pu stockpiles in addition to potential hazard of HLW in "20 GWe constant after 2030" case. Meanwhile, it was also revealed the benefits of reduction of radioactive waste generation and Pu stockpiles in "Gradual decrease from 20 GWe after 2030" case.

Experimental Study of Effect of Geometry on Density-Head-Driven Instability in Boiling Channels

Kotani, Koichi*; Nakao, Toshitsugu*; Sumida, Isao*; Yokomizo, Osamu*; Matsumoto, Tomoyuki*

Journal of Nuclear Science and Technology, 17(10), p.791 - 793, 1980/10

https://doi.org/10.1080/18811248.1980.9732655

Studies on krypton immobilization technology using ion-implantation and sputtering process, 19; Retention characteristic of radioactive Kr immobilized alloy

Samoto, Hirotaka; Kimura, Norimichi; Otani, Takehisa; Sugai, Eiji; Takahashi, Makoto; Hayashi, Shinichiro; Akutsu, Tomoyuki*

no journal, , 

Krypton is immobilized to metal alloy by ion-implantation and sputtering process. The retention characteristic of immobilized radioactive Kr with different storage temperature of the metal alloy is reported.

An Attempt of fault activity assessment using element transfer in fault zones of basement rocks

Otani, Tomoyuki*; Kutsuna, Ryosuke*; Kojima, Satoru*; Ohashi, Kiyokazu*; Kakamu, Kazuhiko

no journal, , 

Development of technique in order to judge the activities of fault using chemical characteristics of active faults is useful for the assessment of faults at geological disposal sites. In this study, element transfer at fault gauge was examined. MnO contents were enriched at fault gauge of the Adera and Neodani faults. Most of Mn-bearing minerals are amorphous, it is suggested that Mn-bearing minerals were precipitated from reduced groundwater at oxidized condition when fault gauge were formed.

Manganese concentration in the latset slip plane of the Neodani fault

Kutsuna, Ryosuke*; Otani, Tomoyuki*; Kojima, Satoru*; Enami, Masaki*; Kakamu, Kazuhiko; Wakai, Shoji

no journal, , 

no abstracts in English

Studies on krypton immobilization technology using ion-implantation and sputtering process; Parametric study of electrode geometry of enlarged krypton gas immobilizing chamber

Otani, Takehisa; Takahashi, Makoto; Akutsu, Tomoyuki*; Kimura, Norimichi; Tanaka, Yukiyoshi

no journal, , 

Optimum geometry of electrodes, which were equipped at the top and bottom of the krypton gas immobilizing chamber, was investigated for improvement of the immobilizing capability with enlarged krypton gas immobilizing chamber.

Relationship of the fault gouge ruptured by the earthquake in eastern Fukushima on April 11, 2011 and element mobility in the fault zone

Otani, Tomoyuki*; Yamashita, Mitsumasa*; Kojima, Satoru*; Wakai, Shoji*; Kakamu, Kazuhiko

no journal, , 

no abstracts in English

Fault exploration based on the microcrack distribution pattern; The Example of the Tsukiyoshi fault, central Japan

Otani, Tomoyuki*; Okazaki, Kazunari*; Nishimura, Yuki*; Kojima, Satoru*; Kuboshima, Koji; Sasao, Eiji; Tsuruta, Tadahiko

no journal, , 

no abstracts in English

Relation of the Tsukiyoshi fault and orientation distribution of microcracks in the borehole MIU-3 core in Mizunami City, Gifu Prefecture

Otani, Tomoyuki*; Yokoi, Kosuke*; Okazaki, Kazunari*; Nishimura, Yuki*; Kojima, Satoru*; Kuboshima, Koji*; Sasao, Eiji

no journal, , 

The orientation of microcracks was measured using the MIU-3 core penetrating the Tsukiyoshi fault to clarify the relation of the microcrack distribution near the fault. Attitude of microcracks in quartz grains in granite are measured under the optical microscope with the universal stage using three perpendicular thin sections. The healed microcracks was probably formed prior to the sealed microcracks. Both healed and sealed microcracks with moderate dip appears near the fault. The distribution of microcracks with moderate dip shows that the preferred orientation of microcracks near the fault is different from that far from the fault. The distribution of the sealed microcracks with moderate dip is narrower than that of the healed microcracks. This shows that the healed microcracks with moderate dip was developed in the intact granite at the earlier stage of the faulting history, and the sealed microcracks was in the weak fault zone which has repeated rupturing and healing at the later.

Relationship between cooling temperature and energy shift of a mechanically-cooled Ge detector

Maeda, Satoshi; Yoda, Tomoyuki; Okazaki, Tsutomu; Otani, Shuichi; Saegusa, Jun

no journal, , 

no abstracts in English