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-ray visualization survey meter in high gamma and neutron background environmentTsubota, Yoichi; Kobayashi, Kenji; Ishii, Tatsuya; Hirato, Misaki; Shioya, Satoshi; Nakagawa, Takahiro
Radiation Protection Dosimetry, 200(16-18), p.1676 - 1680, 2024/11
Times Cited Count：0 Percentile：0.00(Environmental Sciences)In the decommissioning of the Fukushima Daiichi Nuclear Power Station (FDNPS, 1F), workers are removing structures from inside the buildings, monitoring radioactive contamination, and decontaminating inside the buildings. For the measurement of contamination of suit surfaces of workers, we have developed a hand-held survey meter that can measure and visualize surface radioactive contamination of -nuclides in a high 
/ 
-ray background environment. In order to selectively measure -nuclides, we designed and built a prototype hand-held survey meter for -rays, which consists of a thin-film ZnS:Ag scintillator, a multi-anode photomultiplier tube (MA-PMT), individual amplification and counting circuits for each channel of the MA-PMT. Based on the result of -ray counting, the developed device is capable of counting the -radiation beyond 2.1
10
cpm. In the -ray response test, there was no -ray response even when the detector was in close proximity to a high intensity source; The dose rate was estimated to be more than 1 Sv/h. In the future, we plan to reduce the weight and size of the device, as well as improve the usability of the device through actual testing in contaminated environments.
Yamaki, Tetsuya; Kobayashi, Misaki*; Asano, Masaharu; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari; Yoshida, Masaru*
Proceedings of Sadoway 60 Symposium, p.114 - 120, 2010/06
My presentation deals with the application of high-energy heavy ion beams from the cyclotron accelerator of Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with hundreds of MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. Interestingly, the resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. According to microscopic observations, this is probably because the columnar electrolyte phase extended, with a width of tens-to-hundreds nanometers, through the membrane.
Nishi, Masataka; Hayashi, Takumi; Shu, Wataru; Nakamura, Hirofumi; Kawamura, Yoshinori; Yamada, Masayuki; Suzuki, Takumi; Iwai, Yasunori; Kobayashi, Kazuhiro; Isobe, Kanetsugu; et al.
Materialovedenie (Russian Science of Materials) No.2, p.42 - 45, 2002/00
no abstracts in English
Yamaki, Tetsuya; Kobayashi, Misaki*; Asano, Masaharu; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari; Yoshida, Masaru*
no journal, ,
This study deals with the application of high-energy heavy ion beams from the cyclotron accelerator of Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with hundreds of MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. The resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. The through-plane proton conductivity, which is a more direct measurement of the membrane's conductivity and is of interest in an operating fuel cell, was comparable to that of a Nafion112 membrane at the same ion exchange capacity level.
Nishino, Saki; Nemoto, Ryo*; Hayashi, Hiroyuki*; Kobayashi, Daisuke; Isomae, Hidemi; Sakuma, Shuhei; Takimoto, Misaki; Okuyama, Shun; Unno, Motoyoshi; Kitao, Takahiko
no journal, ,
At the JAEA Tokai Reprocessing facility, especially workers engaged in Plutonium Conversion Development Facility (PCDF) are required strict radiation control due to working environment handling various nuclear material including plutonium (Pu) at short range. Because the equivalent dose limit of the lens of the eye stipulated by Japanese regulations has been revised downwards, we reassessed personal dose equivalent focusing on the lens of the worker's eye. The reassessment results indicate that wearing the appropriate radiation protection glasses is necessary for some workers who handle Pu including waste material in PCDF. Radiation management using protective glasses has started under revised radiation control plan.
Kobayashi, Misaki*; Yamaki, Tetsuya; Nomura, Kumiko*; Takagi, Shigeharu*; Asano, Masaharu; Yoshida, Masaru; Maekawa, Yasunari
no journal, ,
To realize mass commercialization of fuel cell, many kinds of properties, such as high proton conductivity, low water swelling and high mechanical strength, are required for a polymer electrolyte membrane. Utilizing nano-scale controllability of an ion beam is our strategic way for the preparation of fuel-cell electrolyte membranes. The preparation of membranes involve (1) the irradiation of heavy ions with different masses and energies; (2) the grafting of styrene into electronically-excited region along the ion trajectory called the latent track; (3) sulfonation of the graft chains. According to the FE-SEM and TEM observations, the proton conductive electrolyte part appeared to extend through the membrane thickness with dimensions of tens-to-hundreds nanometers, which agreed with the calculated latent track diameter. Correlations between membrane properties, such as proton conductivity and nanostructure were investigated.
Yamaki, Tetsuya; Kobayashi, Misaki*; Asano, Masaharu; Yoshida, Masaru; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari
no journal, ,
Fluoropolymer films were bombarded with swift heavy ions to produce an activated zone along the incident axis. The chemically active species generated in this so-called ion track were used to initiate the grafting of styrene, and the subsequent sulfonation of the graft chains provided the electrolyte membranes with anisotropic proton conductivity in the thickness direction. These membranes were found to have sufficient mechanical strength as well as highly conductive pathways with a cylindroidal shape of tens-to-hundreds nanometer size.
Yamaki, Tetsuya; Kobayashi, Misaki*; Asano, Masaharu; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari; Yoshida, Masaru*
no journal, ,
Our presentation deals with the application of high-energy heavy ion beams to the preparation of nano-structure controlled electrolyte membranes. The membrane preparation involves (1) irradiation of commercially-available base polymer films with 100 MeV 
O, 400 MeV 
Fe, or 450 MeV 
Xe, (2) graft polymerization of vinyl monomers into latent tracks, and (3) sulfonation of the graft polymers. The resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the through-plane direction. According to microscopic observations, this is probably because the nearly columnar electrolyte phase with a width of tens-to-hundreds nanometers extended through the membrane. Interestingly, our ion irradiation technique would be able to control the nano-structure of proton-conducting pathways in the membranes. Other excellent membrane properties should also be due to such a controlled structure.
Yamaki, Tetsuya; Asano, Masaharu; Kobayashi, Misaki*; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari; Yoshida, Masaru
no journal, ,
In order to develop proton-conductive membranes for PEFCs, we have been using high-energy heavy ion beams from the cyclotron accelerator of TIARA. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. Interestingly, the resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. According to microscopic observations, this is probably because the columnar electrolyte phase extended, with a width of tens-to-hundreds nanometers, through the membrane. Other excellent membrane properties, e.g., sufficient mechanical strength, high dimensional stability, and low gas permeability should be due to such a controlled structure.
Yamaki, Tetsuya; Asano, Masaharu; Kobayashi, Misaki*; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari; Yoshida, Masaru
no journal, ,
We have been using high-energy heavy ion beams from the cyclotron accelerator of Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA to develop proton-conductive membranes for PEFCs. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. Interestingly, the resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. According to microscopic observations, this is probably because the columnar electrolyte phase extended, with a width of tens-to-hundreds nanometers, through the membrane. Other excellent membrane properties, e.g., sufficient mechanical strength, high dimensional stability, and low gas permeability should be due to such a controlled structure.
Mo/
Tc production processNishikata, Kaori; Seki, Misaki; Fujita, Yoshitaka; Takeuchi, Tomoaki; Ide, Hiroshi; Tsuchiya, Kunihiko; Nasu, Takuya*; Takahashi, Shizuka*; Kobayashi, Kazuta*; Takaki, Naoyuki*
no journal, ,
Mo is the parent nuclide of Tc used for medical diagnostic. The Mo is produced by the fission method using the fission of uranium. However, the fission method requires a large investment in terms of nuclear regulation and nuclear non-proliferation. Therefore, in Japan, domestic production by the activation method using the neutron capture reaction of 
Mo is desired. In this study, R&D of Mo/Tc production by the activation method using PWRs was conducted. In this presentation, we report on the conceptual design of a dissolution treatment system for irradiation targets and a MoO
recycling system using spent Mo solution was conducted. In addition, the cost of Tc production was evaluated and further study issues for realization are reported.
