The Japan Health Physics Society Guideline on Dose Monitoring for the Lens of the Eye

Yokoyama, Sumi*; Tsujimura, Norio; Hashimoto, Makoto; Yoshitomi, Hiroshi; Kato, Masahiro*; Kurosawa, Tadahiro*; Tatsuzaki, Hideo*; Sekiguchi, Hiroshi*; Koguchi, Yasuhiro*; Ono, Koji*; et al.

Journal of Radiation Protection and Research, 47(1), p.1 - 7, 2022/03

https://doi.org/10.14407/jrpr.2021.00276

Background: In Japan, new regulations that revise the dose limit for the lens of the eye (the lens), operational quantities, and measurement positions for the lens dose were enforced in April 2021. Based on the international safety standards, national guidelines, the results of the Radiation Safety Research Promotion Fund of the Nuclear Regulatory Authority, and other studies, the Working Group of Radiation Protection Standardization Committee, the Japan Health Physics Society (JHPS) developed a guideline for radiation dose monitoring for the lens. Materials and Methods: The Working Group of the JHPS discussed the criteria of non-uniform exposure and the management criteria set to not exceed the dose limit for the lens. Results and Discussion: In July 2020, the JHPS guideline was published. The guideline consists of three parts: main text, explanations, and 26 questions. In the questions, the corresponding answers were prepared, and specific examples were provided to enable similar cases to be addressed. Conclusion: With the development of guideline on radiation dose monitoring of the lens, radiation managers and workers will be able to smoothly comply with revised regulations and optimise radiation protection.

Cabling technology of NbSn conductor for ITER central solenoid

Takahashi, Yoshikazu; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Uno, Yasuhiro; et al.

IEEE Transactions on Applied Superconductivity, 24(3), p.4802404_1 - 4802404_4, 2014/06

https://doi.org/10.1109/TASC.2013.2287311

Japan Atomic Energy Agency (JAEA) is procuring all amounts of NbSn conductors for Central Solenoid (CS) in the ITER project. Before start of mass-productions, the conductor should be tested to confirm superconducting performance in the SULTAN facility, Switzerland. The original design of cabling twist pitches is 45-85-145-250-450 mm, called normal twist pitch (NTP). The test results of the conductors with NTP was that current shearing temperature (Tcs) is decreasing due to electro-magnetic (EM) load cycles. On the other hand, the results of the conductors with short twist pitches (STP) of 25-45-80-150-450 mm show that the Tcs is stabilized during EM load cyclic tests. Because the conductors with STP have smaller void fraction, higher compaction ratio during cabling is required and possibility of damage on strands increases. The technology for the cables with STP was developed in Japanese cabling suppliers. The several key technologies will be described in this paper.

Application of digital narrow band noise to J-PARC Main Ring

Schnase, A.; Tamura, Fumihiko; Koseki, Tadashi*; Tomizawa, Masahito*; Toyama, Takeshi*; Yoshii, Masahito*; Omori, Chihiro*; Nomura, Masahiro; Yamamoto, Masanobu; Toda, Makoto*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.1446 - 1448, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupea051.pdf

ITER activities and fusion technology

Seki, Masahiro

Nuclear Fusion, 47(10), p.S489 - S500, 2007/10

https://doi.org/10.1088/0029-5515/47/10/S01

In the 21st IAEA Fusion Energy Conference, 68 and 67 papers were presented in the categories of ITER activities and the fusion technology, respectively. ITER performance prediction, results of technology R&D and the construction preparation provide good confidence of ITER realization. Superconducting tokamak EAST achieved the first plasma just before the conference. Constructions of other new experimental machines have also shown steady progress. Future reactor studies stress the importance of down sizing and steady state approach. Reactor technology in the field of blanket including the ITER TBM program and materials for demonstration power plant showed sound progress in both R&D and design activities.

Development of fusion nuclear technologies at Japan Atomic Energy Research Institute

Seki, Masahiro; Yamanishi, Toshihiko; Shu, Wataru; Nishi, Masataka; Hatano, Toshihisa; Akiba, Masato; Takeuchi, Hiroshi; Nakamura, Kazuyuki; Sugimoto, Masayoshi; Shiba, Kiyoyuki; et al.

Fusion Science and Technology, 42(1), p.50 - 61, 2002/07

https://doi.org/10.13182/FST02-A212

Latest status on development of long-term fusion nuclear technologies at JAERI is overviewed. A tritium processing system for the ITER and DEMO reactors was designed and basic technologies for each component of this system was demonstrated successfully by an operation of the integrated system for one month. An ultra-violet laser with a wave length of 193 nm was found quite effective for removing tritium from in-vessel components of D-T fusion reactors. Blanket technologies have been developed for the Test Blanket Module of the ITER and for advanced blankets for DEMO reactors. This blanket is composed of LiTiO breeder pebbles and neutron multiplier Be pebbles, contained in a box structures made of a reduced activation ferritic steel F82H. Mechanical properties of F82H under neutron irradiation up to 50 dpa were obtained in a temperature range from 200 to 500C. Design of the International Fusion Materials Irradiation Facility (IFMIF) has been developed so as to obtain engineering data for candidate materials for DEMO reactors, under neutron irradiation up to 100-200 dpa.

Fusion reactor technology; Challenge to future energy

Seki, Masahiro; Hishinuma, Akimichi; Kurihara, Kenichi; Akiba, Masato; Abe, Tetsuya; Ishitsuka, Etsuo; Imai, Tsuyoshi; Enoeda, Mikio; Ohira, Shigeru; Okumura, Yoshikazu; et al.

Kaku Yugoro Kogaku Gairon; Mirai Enerugi Eno Chosen, 246 Pages, 2001/09

no abstracts in English

Development and testing of large-scale nuclear components and remote handling system in JAERI

Seki, Masahiro; Ohara, Yoshihiro; Tada, Eisuke; Akiba, Masato

Fusion Engineering and Design, 51-52, p.941 - 948, 2000/11

https://doi.org/10.1016/S0920-3796(00)00414-2

no abstracts in English

Fusion reactor safety; Issues and perspective

Inabe, Teruo; Seki, Masahiro; Tsunematsu, Toshihide

Fusion Engineering and Design, 42, p.7 - 12, 1998/00

https://doi.org/10.1016/S0920-3796(98)00122-7

no abstracts in English

Prospect and attractiveness of fusion research and development toward an experimental reactor

Seki, Masahiro; ; Matsuda, Shinzaburo; *; *; *; Nishi, Masataka; *; Tokuda, Shinji; *; et al.

Denki Gakkai Gijutsu Hokoku, 0(613), 102 Pages, 1996/00

no abstracts in English

Compatibility test of blanket structural materials with beryllium sphere in helium gas environment

Kurasawa, Toshimasa; Takatsu, Hideyuki; Seki, Masahiro; *; *

JAERI-Tech 95-011, 24 Pages, 1995/03

JAERI-Tech-95-011.pdf:2.09MB

no abstracts in English