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.

Development of the multi-cubic -ray spectrometer and its performance under intense Cs and Co radiation fields

Kaburagi, Masaaki; Shimazoe, Kenji*; Kato, Masahiro*; Kurosawa, Tadahiro*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*

Nuclear Instruments and Methods in Physics Research A, 1010, p.165544_1 - 165544_9, 2021/09

https://doi.org/10.1016/j.nima.2021.165544

The number of nuclear facilities being decommissioned has been increasing worldwide, in particular following the accident of the Tokyo Electric Power Company Holdings' Fukushima Daiichi Nuclear Power Station in 2011. In these nuclear facilities, proper management of radioactive materials is required. Then, A -ray spectrometer with four segmentations using small volume CeBr scintillators with a dimension of was developed. The four scintillators were coupled to a multi-anode photomultiplier tube specific to intense radiation fields. We performed the -ray exposure study under Cs and Co radiation fields. Under the Cs radiation field, the relative energy resolution at 1375 mSv/h was the relative energy resolution at 1375 mSv/h was 9.20.05%, 8.00.08%, 8.00.03%, and 9.00.04% for the four channels, respectively.

Current situations and discussions in Japan in relation to the new occupational equivalent dose limit for the lens of the eye

Yokoyama, Sumi*; Hamada, Nobuyuki*; Hayashida, Toshiyuki*; Tsujimura, Norio; Tatsuzaki, Hideo*; Kurosawa, Tadahiro*; Nabatame, Kuniaki*; Oguchi, Hiroyuki*; Ono, Kazuko*; Kawaura, Chiyo*; et al.

Journal of Radiological Protection, 37(3), p.659 - 683, 2017/09

https://doi.org/10.1088/1361-6498/aa73e8

Since the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye in 2011, there have been extensive discussions in various countries. This paper reviews the current situations in radiation protection of the ocular lens and the discussions on the potential impact of the new lens dose limit in Japan. Topics include historical changes to the lens dose limit, the current situations in occupational lens exposures (e.g., in medical workers, nuclear workers, and Fukushima nuclear power plant workers) and measurements, and the current status of biological studies and epidemiological studies on radiation cataracts. Our focus is on the situations in Japan, but we believe such information sharing will be useful in many other countries.

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 3; Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.

JAEA-Research 2014-030, 457 Pages, 2015/03

JAEA-Research-2014-030.pdf:199.23MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.

Acquisition of the data and their conversion to the data bases for the radionuclides migration under deep underground environment

Yoshikawa, Hideki; Shibata, Masahiro; Sasamoto, Hiroshi; Iijima, Kazuki; Sato, Haruo; Kitamura, Akira; Ishidera, Takamitsu; Fujiwara, Kenso; Kurosawa, Susumu; Xia, X.; et al.

Hoshasei Haikibutsu Anzen Kenkyu Nenji Keikaku (Heisei-13-NendoHeisei-17-Nendo) Kenkyu Seika Hokokushu, p.153 - 170, 2006/03

no abstracts in English

Analyses of neutron and ray measurements in a target room of several tens MeV Proton Facility

Nakashima, Hiroshi; Masumura, Tomomi*; Tanaka, Susumu; Sakamoto, Yukio; Takada, Hiroshi; Tanaka, Shunichi; Nakane, Yoshihiro; Meigo, Shinichiro; Nakamura, Takashi*; Kurosawa, Tadahiro*; et al.

Journal of Nuclear Science and Technology, 37(Suppl.1), p.192 - 196, 2000/03

https://doi.org/10.1080/00223131.2000.10874873

no abstracts in English

Study on the neutron dosimetric characteristics of tissue equivalent proportional counter

Nunomiya, Tomoya*; Kim, E.*; Kurosawa, Tadahiro*; Taniguchi, Shingo*; Nakamura, Takashi*; Tsujimura, Norio; Momose, Takumaro; Shinohara, Kunihiko

JNC TY8400 99-007, 29 Pages, 1999/03

JNC-TY8400-99-007.pdf:1.31MB

None

Source neutron spectra of radiation streaming measurement in a labyrinth

Sakamoto, Yukio; Tanaka, Susumu; ; Nakane, Yoshihiro; Meigo, Shinichiro; Takada, Hiroshi; Tanaka, Shunichi; Takada, M.*; Kurosawa, Tadahiro*; Nakamura, Takashi*; et al.

Genshikaku Kenkyu, 41(3), p.95 - 99, 1996/06

no abstracts in English

Reevaluation of secondary neutron spectra from thick targets upon heavy-ion bombardment

Satoh, Daiki; Kurosawa, Tadahiro*; Sato, Tatsuhiko; Endo, Akira; Takada, Masashi*; Iwase, Hiroshi*; Nakamura, Takashi; Niita, Koji*

no journal, , 

Previously-published data of secondary neutron spectra from thick targets of C, Al, Cu and Pb bombarded with heavy ions from He to Xe are revised by using a new set of neutron-detection efficiency values for a liquid organic scintillator calculated with SCINFUL-QMD. Additional data have been measured for bombardment of C target by 400-MeV/nucleon C ions and 800 MeV/nucleon Si-ions. The set of spectra are compared with the calculation results using a Monte-Carlo heavy-ion transport code, PHITS. It was found that PHITS is able to reproduce the secondary neutron spectra in a wide neutron-energy regime.

Development of -ray spectrometry system suited in high dose-rate radiation fields for use in non-destructive assay of nuclear fuel debris

Kaburagi, Masaaki; Shimazoe, Kenji*; Kurosawa, Tadahiro*; Kato, Masahiro*; Takahashi, Hiroyuki*

no journal, , 

no abstracts in English