Analysis of the radioactivity concentrations in radioactive waste generated from JRR-3, JRR-4 and JRTF facilities

Tobita, Minoru*; Konda, Miki; Omori, Takeshi*; Nabatame, Tsutomu*; Onizawa, Takashi*; Kurosawa, Katsuaki*; Haraga, Tomoko; Aono, Ryuji; Mitsukai, Akina; Tsuchida, Daiki; et al.

JAEA-Data/Code 2022-007, 40 Pages, 2022/11

JAEA-Data-Code-2022-007.pdf:1.99MB

Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete, ash, ceramic and brick samples generated from JRR-3, JRR4 and JRTF facilities. In this report, we summarized the radioactivity concentrations of 24 radionuclides (H, C, Cl, Ca, Co, Ni, Sr, Nb, Tc, Ag, I, Cs, Ba, Eu, Eu, Ho, U, U, Pu, Pu, Pu, Am, Am, Cm) which were obtained from radiochemical analysis of the samples in fiscal years 2020-2021.

In-plane orientation control of 2,7-diphenyl[1]benzothieno[3,2-][1]benzothiophene monolayer on bismuth-terminated Si(111) vicinal surfaces with wettability optimization

Otomo, Manabu; Tsuchida, Yuya*; Muraya, Naoki*; Yanase, Takashi*; Sakai, Seiji; Yonezawa, Tetsu*; Nagahama, Taro*; Hasegawa, Tetsuya*; Shimada, Toshihiro*

Journal of Physical Chemistry C, 117(22), p.11555 - 11561, 2013/06

https://doi.org/10.1021/jp3117837

We report in-plane orientation control of newly developed high-mobility organic semiconductor: 2,7-diphenyl[1]benzothieno[3,2-][1]benzothiophene (DPh-BTBT). As previously reported on monolayer pentacene, it was revealed that bunched steps on vicinal Si(111) with bismuth termination break the surface symmetry and reduce three-fold symmetry of DPh-BTBT grains into quasi-single orientation. Interestingly, the critical step height necessary for the orientation control was different from that of pentacene. We examined several mechanisms of orientation control and concluded that the facet nano structure fabricated by step bunching is working as an anisotropic template. We will also show the wettability control of bismuth terminated silicon surface and show that the growth mode of DPh-BTBT is dependent on the surface nanostructure of Bi-Si.

Voltage holding study of 1 MeV accelerator for ITER neutral beam injector

Taniguchi, Masaki; Kashiwagi, Mieko; Umeda, Naotaka; Dairaku, Masayuki; Takemoto, Jumpei; Tobari, Hiroyuki; Tsuchida, Kazuki; Yamanaka, Haruhiko; Watanabe, Kazuhiro; Kojima, Atsushi; et al.

Review of Scientific Instruments, 83(2), p.02B121_1 - 02B121_3, 2012/02

https://doi.org/10.1063/1.3675389

JAEA has developed the MeV accelerator to demonstrate 1 MeV, 200 A/m H ion beam acceleration required for ITER NBI. A key to realize such a high power accelerator is improvement of voltage holding capability. Based on detailed investigation of the voltage holding characteristics, MeV accelerator was modified to reduce electric field concentration by extending gaps between the grid supports and increasing curvature radiuses at the support corners. After the modifications, accelerator succeeded in sustaining -1 MV in vacuum without beam acceleration. Moreover, beam deflection due to the magnetic field for electron suppression and space charge repulsion was compensated by aperture displacement technique. As the result, beam deflection was compensated and voltage holding during the beam acceleration was improved. Beam parameter of the MeV accelerator was increased to 980 keV, 185 A/m, which is close to the requirement of ITER accelerator.

A Possible overestimation of the effect of acetylation on lysin residues in KQ mutant analysis

Fujimoto, Hirofumi*; Higuchi, Mariko; Koike, Manabu*; Ode, Hirotaka*; Pinak, M.; Kotulic Bunta, J.*; Nemoto, Toshiyuki*; Sakudo, Takashi*; Honda, Naoko*; Maekawa, Hideaki*; et al.

Journal of Computational Chemistry, 33(3), p.239 - 246, 2012/01

https://doi.org/10.1002/jcc.21956

Lysine acetylation is one of the most common protein post transcriptional modifications. The acetylation effects of lysine residues on Ku protein were examined herein applying several computer simulation techniques. Acetylation of the lysine residues did not reduce the affinity between Ku and its substrate, DNA, in spite of the fact that the substitution of lysine with glutamine (KQ mutant) reduced the affinity of Ku for DNA, or the substitution of lysine with arginine (KR mutant) did not reduce it, as previously reported in experimental studies. These results suggest that the effects of in vivo acetylation may be overestimated when the KQ mutant is employed in mimicry of the acetylated protein.

Improvement of voltage holding and high current beam acceleration by MeV accelerator for ITER NB

Taniguchi, Masaki; Kashiwagi, Mieko; Inoue, Takashi; Umeda, Naotaka; Watanabe, Kazuhiro; Tobari, Hiroyuki; Dairaku, Masayuki; Yamanaka, Haruhiko; Tsuchida, Kazuki; Kojima, Atsushi; et al.

AIP Conference Proceedings 1390, p.449 - 456, 2011/09

https://doi.org/10.1063/1.3637416

At JAEA, MeV accelerator has been developed as a proof-of-principle accelerator for ITER NBI. To achieve the acceleration of 1 MeV, 200 A/m beam required for ITER, improvement of the voltage holding capability is essential. Review of voltage holding results ever obtained with various geometries of the accelerators showed that voltage holding capability was about a half of that for ideal small electrode. This is due to local electric field concentration in the accelerators, such as edge and corner between grids and its support structures. Based on these results, accelerator was modified to reduce the electric field concentration by reshaping the support structures and expanding the gap length. After the modifications, voltage holding capability in vacuum was increased from 835 kV to 1 MV. Voltage holding progressed the energy and current to 879 keV, 0.36 A (157 A/m).

Development of high voltage power supply system for ITER neutral beam injector

Tsuchida, Kazuki; Watanabe, Kazuhiro; Tobari, Hiroyuki; Takemoto, Jumpei; Yamanaka, Haruhiko; Inoue, Takashi

Denki Gakkai Kenkyukai Shiryo, Genshiryoku Kenkyukai (NE-11-001004 006010), p.17 - 22, 2011/09

A 1 MeV high-energy neutral beam injector is under developing for heating and current drive of ITER plasma in collaboration with EUDA. JADA will provide ultra-high voltage DC power supply components. Design of the 1 MV power supply, R&Ds on a HV bushing and a water choke will be presented. These results satisfy the requirements for the NBI system.

Development of radiation-resistant lighting

Tsuchida, Takashi*; Yamagata, Ryohei; Seito, Hajime; Haruyama, Yasuyuki; Kaneko, Hirohisa; Kashimura, Shinji*

JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 22, 2011/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2010-065.pdf

There are a lot of restrictions of electric installations in a high radiation environment. For example longevity of electric devices would be shortened remarkably in a high radiation environment. It becomes impossible also for lighting equipments to keep an original function under a high radiological environment due to deterioration of insulation resistance of ballasts and luminous flux decrease of lamps, etc. The authors developed radiation-resistant lighting. This research aims to verify those functionality and safety under -ray irradiation conditions.

Development and procurement of the ITER NB power supplies

Watanabe, Kazuhiro; Takemoto, Jumpei; Yamanaka, Haruhiko; Tsuchida, Kazuki; Dairaku, Masayuki; Kashiwagi, Mieko; Taniguchi, Masaki; Tobari, Hiroyuki; Umeda, Naotaka; Inoue, Takashi; et al.

no journal, , 

no abstracts in English

Development of negative ion based neutral beam injector for ITER

Watanabe, Kazuhiro; Umeda, Naotaka; Kashiwagi, Mieko; Dairaku, Masayuki; Takemoto, Jumpei; Taniguchi, Masaki; Tsuchida, Kazuki; Tobari, Hiroyuki; Yamanaka, Haruhiko; Inoue, Takashi; et al.

no journal, , 

In the ITER project, negative-ion-based neutral beam injectors (NBI) which can inject deuterium neutral beams of 1 MeV, 16.5 MW per one injector are planned. The authors will report the subjects of the system and present status of the development for the major components of Japanese procurements for the ITER NBI and the ITER NBI test facility.

Development of 1 MeV accelerator for ITER; Achievement of 0.98 MeV, 185 A/m negative ion beam acceleration

Kashiwagi, Mieko; Taniguchi, Masaki; Umeda, Naotaka; Dairaku, Masayuki; Takemoto, Jumpei; Tsuchida, Kazuki; Tobari, Hiroyuki; Yamanaka, Haruhiko; Watanabe, Kazuhiro; Sakamoto, Keishi; et al.

no journal, , 

In a MeV accelerator test for the ITER neutral beam injector (NBI), beam acceleration tests are progressed toward 1 MeV, 200 A/m H ion beams. As results of suppression of breakdowns due to local electric field concentrations and suppression of direct interception of deflected beamlets due to magnetic field and space charge repulsion, the beam parameters increased from 0.8 MeV to 0.98 MeV, 185 A/m. This is achieving the target value. After this achievement, the results of the MeV accelerator are applied to the ITER accelerator design.