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.

Detection limit of electron spin resonance for Japanese deciduous tooth enamel and density separation method for enamel-dentine separation

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; Sasaki, Keiichi*; et al.

Journal of Radiation Research (Internet), 63(4), p.609 - 614, 2022/07

https://doi.org/10.1093/jrr/rrac033

Electron spin resonance (ESR) dosimetry is one of the most powerful tools for radiation dose reconstruction. The detection limit of this technique using human teeth is reported to be 56 mGy or 67 mGy; however, the absorbed dose of Fukushima residents after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident was estimated to be lower than this detection limit. Our aim is to assess the absorbed radiation dose of children in Fukushima Prefecture after the accident; therefore, it is important to estimate the detection limit for their teeth. The detection limit for enamel of deciduous teeth of Japanese children separated by the mechanical method is estimated to be 115.0 mGy. The density separation method can effectively separate enamel from third molars of Japanese people. As we have collected thousands of teeth from children in Fukushima, the present technique may be useful to examine their external absorbed dose after the FNPP accident.

Rapid analysis of Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometry

Koarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.

Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08

https://doi.org/10.1039/D1JA00086A

Rapid analysis of Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of Sr in small bone and tooth samples derived from terrestrial animals.

External exposure dose estimation by electron spin resonance technique for wild Japanese macaque captured in Fukushima Prefecture

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.

Radiation Measurements, 134, p.106315_1 - 106315_4, 2020/06

https://doi.org/10.1016/j.radmeas.2020.106315

The relationship between the CO radical intensity and the absorbed dose (dose response curve) of tooth enamel of Japanese macaque was observed by electron spin resonance and the detection limit of our system was estimated to be 33.5 mGy, which is comparable to the detection limit for human molar teeth. Using the dose response curve, external exposure dose for seven wild Japanese macaques captured in Fukushima prefecture were examined. The results suggest that the external exposure dose for the wild Japanese macaques were ranged between 45 mGy to 300 mGy.

Development of pellet injector using screw type pellet extruder; Improvement of pellet extruder for high frequency and long duration, and its test results

Ichige, Hisashi; Honda, Masao; Sasaki, Shunichi; Takenaga, Hidenobu; Matsuzawa, Yukihiro; Haga, Saburo; Ishige, Yoichi

JAEA-Technology 2007-037, 16 Pages, 2007/07

JAEA-Technology-2007-037.pdf:2.91MB

In JT-60U, pellet injector has been developed for improvement of density controllability and long operation duration consistent with a long pulse discharge (65 s) started from FY2003. The injection frequency and operation duration were limited by extrusion speed and volume of the piston type pellet extruder, respectively, in the previous system. The screw type pellet extruder made in Russian company was newly installed in the system, which can continuously extrude the pellet at high speed and has been used in other fusion devices. After parts of the pellet injector system moved from JT-60 torus hall for efficient work, the previous piston type pellet extruder was changed to the new screw type pellet extruder and the tests for continuous pellet extrusion were performed. In the extrusion test using deuterium gas as a working gas, continuous pellet extrusion up to 330s was achieved, which is sufficient performance for applying it to JT-60U experiments.

Study on the Monitoring Methods for Engineered Barriers Performance Confirmation

Chijimatsu, Masakazu*; Imai, Hisashi*; Sasaki, Hajime*; Moro, Yoshiji*

JNC TJ8400 2003-090, 116 Pages, 2004/02

JNC-TJ8400-2003-090.pdf:3.43MB

This study investigates the methodology for the engineered barriers performance confirmation. First of all the investigation about the monitoring concept in foreign countries were performed and the monitoring aiming was fixed at the performance confirmation of the engineered barriers. The monitoring item and the element of engineered barriers were set as followings, namely temperature, hydraulic pressure, water contents, pH, Eh and the chemistry of solutions. The indirect measuring method of items both providing the engineered barriers performance and varying with exhibition of performance from the rock around the engineered barriers is proposed for the engineered barriers performance confirmation monitoring. Finally the problems to be solved for the future monitoring program are clarified, and the plan of R&D for sensing methods in the performance assessment, and the in-situ experimental plan in the Horonobe deep underground research center are proposed.

Study on Groundwater Flow Characteristics in Horonobe Underground Research Laboratory Project

Imai, Hisashi*; Fukudome, Kazuto*; Kayukawa, Koji*; Sasaki, Hajime*; Chijimatsu, Masakazu*; Moro, Yoshiji*

JNC TJ5400 2003-009, 223 Pages, 2004/02

JNC-TJ5400-2003-009.pdf:59.94MB
JNC-TJ5400-2003-009(errata).pdf:0.08MB

In order to search for an appropriate methodology of the regional groundwater flowanalysis for sedimentary rock mass area, the following four studies were carried out: 1) Two simulation region setting and data set arrangement of the two region for numerical simulation of groundwater flow 2) Evaluation of regional groundwater flow characteristics in the Horonobe Project site using the results of the numerical simulation and obtained field data 3) Estimation of the shaft excavation effect on the groundwater flow such as the inflow rate of groundwater into the shafts, the chroline contents of groundwater flowing into the shafts and the hydraulic head evolution around the shafts 4) Proposal of desirable investigations for the next stage : the methodology of evaluating groundwater flow characteristics

A Repetitive pellet injection system for JT-60U

Kizu, Kaname; Hosogane, Nobuyuki; Hiratsuka, Hajime; Ichige, Hisashi; Sasajima, Tadayuki; Masaki, Kei; Miya, Naoyuki; Honda, Masao; Iwahashi, Takaaki*; Sasaki, Noboru*; et al.

Fusion Engineering and Design, 58-59, p.331 - 335, 2001/11

https://doi.org/10.1016/S0920-3796(01)00310-6

no abstracts in English

Development of the centrifugal pellet injector in JT-60U

Hiratsuka, Hajime; Kizu, Kaname; Ichige, Hisashi; Honda, Masao; Iwahashi, Takaaki*; Sasaki, Noboru*; Miya, Naoyuki; Hosogane, Nobuyuki; Oda, Yasushi*; Yoshida, Kazuto*

Purazuma, Kaku Yugo Gakkai-Shi, 76(11), p.1189 - 1197, 2000/11

http://ci.nii.ac.jp/naid/110003825480

no abstracts in English

Guide to development of a scalar massive parallel programming on Paragon

Ueshima, Yutaka*; Arakawa, Takuya*; Sasaki, Akira; Yokota, Hisashi*

JAERI-Data/Code 98-030, 69 Pages, 1998/10

JAERI-Data-Code-98-030.pdf:2.07MB

no abstracts in English