Estimation of external dose for wild Japanese macaques captured in Fukushima prefecture; Decomposition of electron spin resonance spectrum

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.

Radiation Protection Dosimetry, 199(14), p.1620 - 1625, 2023/09

https://doi.org/10.1093/rpd/ncad146

We have been conducting dose assessments for Japanese macaques captured in Fukushima to reveal radiobiological effects on the low-dose expose animals. To accurately determine the external exposure dose, it is desirable to examine the analysis of the CO radical intensity. We examined ESR spectra of teeth of 10 macaques captured in Fukushima by two spectrum-decomposition algorithms.

Development of dose estimation method using wild animal teeth for low dose exposure

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.

KEK Proceedings 2021-2, p.91 - 96, 2021/12

We examined whether the ESR dose estimation method could be applied to wild Japanese macaque. In this work, we investigated the enamel preparation protocol and the analytical method of the ESR spectra.

Development of cesium trap material for coated fuel particles in high temperature gas-cooled reactors

Sasaki, Koei; Miura, Shuichiro*; Fukumoto, Kenichi*; Goto, Minoru; Ohashi, Hirofumi

Proceedings of 28th International Conference on Nuclear Engineering (ICONE 28) (Internet), 6 Pages, 2021/08

https://doi.org/10.1115/ICONE28-61765

Cs-Bi and Cs-Sb absorbed graphite samples (Cs-Bi/graphite and Cs-Sb/graphite) were synthesized and their high temperature chemical stabilities were tested up to 1500C by TG and analyzed by TEM-EDS for the development of Cs trap material in high temperature gas-cooled reactor (HTGR) fuel particles. It was observed that Cs was stabilized by Sb but not by Bi in the specimens after the TG test. A rapid weight loss from 800 to 1000C may be caused by evaporation of Cs (boiling point: 671C) was seen in the TG result of both specimens. Precipitated Cs-Sb substance in the graphite matrix were not resolved even after the 1500C heating. The chemical composition of the Cs-Sb was specified as CsSb. The experimental results suggest that Sb have potential to be a Cs getter material in graphite matrix. Long term heating test should be performed to confirm adaptability of Sb for Cs trap material in HTGR fuel particles.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

https://doi.org/10.1051/epjconf/201919800003

Cs-Te corrosion depth dependence on distribution of chromium carbide precipitation in high chromium steel

Sasaki, Koei; Fujimura, Ryota*; Tanigaki, Takanori; Matsubara, Masanori*; Fukumoto, Kenichi*; Uno, Masayoshi*

Journal of Nuclear Science and Technology, 54(2), p.139 - 146, 2017/02

AA2016-0211.pdf:2.83MB

https://doi.org/10.1080/00223131.2016.1214628

In an attempt to investigate Cs-Te corrosion depth dependence on distribution of chromium carbide precipitation in high chromium steel, Cs-Te corrosion out-pile tests of two 9Cr steels with different distributions of chromium carbide were carried out at 975K for 100h and their corrosion depths were compared. The corrosion is obviously more advanced in a specimen which has grain boundary carbide than in the one that does not. A considerable reason of the result is that the carbide distributed at grain boundaries promoted the corrosion reaction and the corrosion extended along the grain boundary. This is the first case in which the Cs-Te corrosion depth dependence on distribution of chromium carbide precipitation in Fe-Cr steel is clarified experimentally.

Study on radionuclide analysis of rubble and plants for decommissioning of Fukushima Daiichi Nuclear Power Station

Seki, Kotaro; Sasaki, Takayuki*; Akimoto, Yuji*; Tokunaga, Takahito; Tanaka, Kiwamu; Haraga, Tomoko; Ueno, Takashi; Ishimori, Kenichiro; Hoshi, Akiko; Kameo, Yutaka

JAEA-Technology 2016-013, 37 Pages, 2016/07

JAEA-Technology-2016-013.pdf:2.09MB

In this study, based on the simple and rapid analytical method established from the wastes from research facilities, we created analytical schemes which is applicable to rubble and plants collected at Fukushima Daiichi, then transported to Nuclear Science Research Institute of JAEA. We examined the applicability, and confirmed quantifiability of radioactivity concentration with high recovery rate without being affected by fission products such as Sr and Cs.

Measurement of the spin-flip value in hypernuclei

Sasaki, Yuki*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; et al.

JPS Conference Proceedings (Internet), 8, p.022013_1 - 022013_4, 2015/09

https://doi.org/10.7566/JPSCP.8.022013

Interface-dependent magnetotransport properties for thin Pt films on ferrimagnetic YFeO

Shiomi, Yuki*; Otani, Takashi*; Iguchi, Satoshi*; Sasaki, Takahiko*; Qiu, Z.*; Nakayama, Hiroyasu*; Uchida, Kenichi*; Saito, Eiji

Applied Physics Letters, 104(24), p.242406_1 - 242406_5, 2014/06

https://doi.org/10.1063/1.4883898

Observation of in-plane asymmetric strain relaxation during crystal growth and growth interruption in InGaAs/GaAs(001)

Sasaki, Takuo*; Shimomura, Kenichi*; Suzuki, Hidetoshi*; Takahashi, Masamitsu; Kamiya, Itaru*; Oshita, Yoshio*; Yamaguchi, Masafumi*

Japanese Journal of Applied Physics, 51(2), p.02BP01_1 - 02BP01_3, 2012/02

https://doi.org/10.1143/JJAP.51.02BP01

Development of advanced tritium breeding material with added lithium for ITER-TBM

Hoshino, Tsuyoshi; Kato, Kenichi*; Natori, Yuri*; Oikawa, Fumiaki; Nakano, Natsuko*; Nakamura, Mutsumi*; Sasaki, Kazuya*; Suzuki, Akihiro*; Terai, Takayuki*; Tatenuma, Katsuyoshi*

Journal of Nuclear Materials, 417(1-3), p.684 - 687, 2011/10

https://doi.org/10.1016/j.jnucmat.2010.12.128

Lithium titanate (LiTiO) is one of the most promising candidates among tritium breeding materials because of its good tritium release. Addition of H to inert sweep gas has been proposed for enhancing the tritium release from tritium breeding materials. However, the mass of LiTiO was decreased with time in the hydrogen atmosphere. It is assumed that the mass decrease indicates the loss of the oxygen contained in the sample caused by the change from Ti to Ti , and that the partial pressures of Li-containing species were increased in the hydrogen atmosphere. In order to decrease the mass-change at high temperature, advanced tritium breeding material with added Li should be developed to improve the physical and chemical stability in hydrogen atmosphere. In the case of the LiTiO samples used by the present study, LiOHHO and HTiO were proportionally mixed with the molar ratio Li/Ti of either 2.0 and 2.2. These samples are designated as L20 (Li/Ti = 2.0) and L22 (Li/Ti = 2.2), respectively. The results of XRD measurement showed that the phases in advanced tritium breeding material were as follows. L22 existed as non-stoichiometric compound LiTiO.