A Phoswich alpha/beta detector for monitoring in the site of Fukushima Daiichi Nuclear Power Station

Morishita, Yuki; Takasaki, Koji; Kitayama, Yoshiharu; Tagawa, Akihiro; Shibata, Takuya; Hoshi, Katsuya; Kaneko, Junichi*; Higuchi, Mikio*; Oura, Masatoshi*

Radiation Measurements, 160, p.106896_1 - 106896_10, 2023/01

https://doi.org/10.1016/j.radmeas.2022.106896

This study proposes a newly developed phoswich alpha/beta detector that can discriminate alpha and beta particles emitted from the alpha and beta contaminations in the FDNPS site. The phoswich alpha/beta detector is made up of two layers of scintillators that detect alpha and beta particles. The pulse shape discrimination (PSD) method was used to detect alpha particles in high beta particle and high gamma-ray (comparable to gamma-ray dose rate near the FDNPS reactor building) environments. Due to a 23.3% full width at half maximum (FWHM) energy resolution for alpha particles, the detector can be used to distinguish between nuclear fuel materials such as plutonium and its radon progeny (Po-214). Moreover, the detector could distinguish alpha particles from Cs gamma rays with a dose rate background up to 9.0 mSv/h. It is the first to demonstrate that the developed phoswich detector can be used to discriminate and measure alpha and beta particles of the actual contaminated FDNPS samples.

Ten years of Fukushima Dai-ichi post-accident research on the degradation phenomenology of the BWR core components

Pshenichnikov, A.; Shibata, Hiroki; Yamashita, Takuya; Nagae, Yuji; Kurata, Masaki

Journal of Nuclear Science and Technology, 59(3), p.267 - 291, 2022/03

https://doi.org/10.1080/00223131.2021.1985647

Non-invasive imaging of radiocesium dynamics in a living animal using a positron-emitting Cs tracer

Suzui, Nobuo*; Shibata, Takuya; Yin, Y.-G.*; Funaki, Yoshihito*; Kurita, Keisuke; Hoshina, Hiroyuki*; Yamaguchi, Mitsutaka*; Fujimaki, Shu*; Seko, Noriaki*; Watabe, Hiroshi*; et al.

Scientific Reports (Internet), 10, p.16155_1 - 16155_9, 2020/10

https://doi.org/10.1038/s41598-020-73351-2

Thermal behavior, structure, dynamic properties of aqueous glycine solutions confined in mesoporous silica MCM-41 investigated by X-ray diffraction and quasi-elastic neutron scattering

Yoshida, Koji*; Inoue, Takuya*; Torigoe, Motokatsu*; Yamada, Takeshi*; Shibata, Kaoru; Yamaguchi, Toshio*

Journal of Chemical Physics, 149(12), p.124502_1 - 124502_10, 2018/09

https://doi.org/10.1063/1.5039892

Differential scanning calorimetry, X-ray diffraction, and quasi-elastic neutron scattering (QENS) measurements of aqueous glycine solutions confined in mesoporous silica (MCM-41) were performed at different glycine concentrations, pH, and loading ratio (= mass of glycine solution / mass of dry MCM-41) in the temperature range from 305 to 180 K to discuss the confinement effect on the thermal behavior, the structure, and the dynamic properties of the solutions.

Neutron irradiation effect of high-density MoO pellets for Mo-99 production, 3

Ishida, Takuya; Suzuki, Yoshitaka; Nishikata, Kaori; Yonekawa, Minoru; Kato, Yoshiaki; Shibata, Akira; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; et al.

KURRI Progress Report 2015, P. 64, 2016/08

http://www.rri.kyoto-u.ac.jp/PUB/report/PR/ProgRep2015/PR2015.pdf#page=73

no abstracts in English

Performance tests of radiation detectors for inspection of Mo/Tc solution, 1

Suzuki, Yumi*; Nakano, Hiroko; Suzuki, Yoshitaka; Ishida, Takuya; Shibata, Akira; Kato, Yoshiaki; Kawamata, Kazuo; Tsuchiya, Kunihiko

JAEA-Technology 2015-031, 58 Pages, 2015/11

JAEA-Technology-2015-031.pdf:14.57MB

Technetium-99m (Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. In the Japan Atomic Energy Agency (JAEA), the research and development (R&D) have been carried out for production of molybdenum-99 (Mo) by (n, ) method, a parent nuclide of Tc, with the Japan Material Testing Reactor (JMTR). On the other hand, the new project as "Domestic Production of Medical Radioisotope (Technetium preparation) in Japan" was adopted in the Tsukuba International Strategic Zone on October, 2013 and the demonstration tests will be planned for the domestic production of Mo/Tc with the JMTR. Thus, new facilities and analysis devices were equipped in the JMTR Hot Laboratory in 2014 as the part of this project. As the part of the analytical device equipment, the -TLC analyzer and the radiation detector connected with the High Performance Liquid Chromatography (HPLC) were installed for quality inspection of the Mo/Tc solution and the extracted Tc solution in the JMTR Hot Laboratory. The performance tests of these devices such as detection sensitivity, resolution, linearity and selectivity of energy range were carried out with Cs and Eu as alternative radionuclides of Mo and Tc, respectively. In the results, bright prospects were obtained concerning the quality inspection of the Mo/Tc and Tc solutions using these devices. This report describes the results of those performance tests.

Development of grafted adsorbents for Cs removal from natural water source

Seko, Noriaki; Shibata, Takuya; Kasai, Noboru; Ueki, Yuji; Saiki, Seiichi; Hoshina, Hiroyuki

Hoshasen To Sangyo, (138), p.9 - 12, 2015/06

no abstracts in English

Development of an adsorbent for Cs removal synthesized by radiation-induced graft polymerization

Shibata, Takuya; Seko, Noriaki; Amada, Haruyo; Kasai, Noboru; Saiki, Seiichi; Hoshina, Hiroyuki; Ueki, Yuji

Nihon Ion Kokan Gakkai-Shi, 26(1), p.9 - 14, 2015/01

https://doi.org/10.5182/jaie.26.9

Optimization of grafted fibrous polymer as a solid basic catalyst for biodiesel fuel production

Ueki, Yuji; Saiki, Seiichi; Shibata, Takuya; Hoshina, Hiroyuki; Kasai, Noboru; Seko, Noriaki

International Journal of Organic Chemistry, 4(2), p.91 - 105, 2014/06

https://doi.org/10.4236/ijoc.2014.42011

Grafted fibrous polymer with quaternary amine groups could function as a highly-efficient catalyst for biodiesel fuel (BDF) production. In this study, the optimization of grafted fibrous polymer (catalyst) and transesterification conditions for the effective BDF production was attempted through a batch-wise transesterification of triglyceride (TG) with ethanol (EtOH) in the presence of a cosolvent. Trimethylamine was the optimal quaternary amine group for the grafted fibrous catalyst. The optimal degree of grafting of the grafted fibrous catalyst was 170%. The optimal transesterification conditions were as follows: The molar quantity of quaternary amine groups, transesterification temperature, molar ratio of TG and EtOH, and primary alkyl alcohol were 0.8 mmol, 80C, 1:200, and 1-pentanol, respectively. The grafted fibrous catalyst could be applied to BDF production using natural oils. Furthermore, the grafted fibrous catalyst could be used repeatedly after regeneration involving three sequential processes, i.e., organic acid, alkali, and alcohol treatments, without any significant loss of catalytic activity.

Development of a water purifier by EB-grafted fiber

Mikami, Takashi*; Nakano, Masanori*; Shibata, Takuya; Seko, Noriaki

Setsubi To Kanri, 47(4), p.95 - 99, 2013/04

no abstracts in English