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JAEA Reports

Effective dose coefficients for internal exposure dose assessment in accordance with ICRP 2007 recommendations (Contract research)

Takahashi, Fumiaki; Manabe, Kentaro; Sato, Kaoru

JAEA-Review 2020-068, 114 Pages, 2021/03

JAEA-Review-2020-068.pdf:2.61MB

Radiation safety regulations have been currently established based on the 1990Recommendation by the International Commission on Radiological Protection (ICRP) in Japan. Meanwhile, ICRP released the 2007 Recommendation that replaces the 1990 Recommendation. Thus, the Radiation Council, which is established under the Nuclear Regulation Authority (NRA), has made discussions to incorporate the purpose of the 2007 Recommendation into Japanese regulations for radiation safety. As ICRP also has published effective dose coefficients for internal exposure assessment in accordance with the 2007recommendation, the technical standards are to be revised for the internal exposure assessment method in Japan. Currently, not all of the effective doses have been published to revise concentration limits for internal exposure protections of workers and public. The published effective dose coefficients are applied to radionuclides which are important in radiation protection for internal exposure of a worker. Thus, we review new effective dose coefficients as well as basic dosimetry models and data based upon Occupational Intakes of Radionuclides (OIR) parts 2, 3 and 4 that have been published from 2016 to 2019 by ICRP. In addition, issues are sorted out to provide information for revision of the technical standards for internal exposure assessment based on the 2007 Recommendations in future.

Journal Articles

A Unique high natural background radiation area; Dose assessment and perspectives

Hosoda, Masahiro*; Nugraha, E. D.*; Akata, Naofumi*; Yamada, Ryohei; Tamakuma, Yuki*; Sasaki, Michiya*; Kelleher, K.*; Yoshinaga, Shinji*; Suzuki, Takahito*; Rattanapongs, C. P.*; et al.

Science of the Total Environment, 750, p.142346_1 - 142346_11, 2021/01

 Times Cited Count:5 Percentile:96.3(Environmental Sciences)

The biological effects of low dose-rate radiation exposures on humans remains unknown. In fact, the Japanese nation still struggles with this issue after the Fukushima Dai-ichi Nuclear Power Plant accident. Recently, we have found a unique area in Indonesia where naturally high radiation levels are present, resulting in chronic low dose-rate radiation exposures. We aimed to estimate the comprehensive dose due to internal and external exposures at the particularly high natural radiation area, and to discuss the enhancement mechanism of radon. A car-borne survey was conducted to estimate the external doses from terrestrial radiation. Indoor radon measurements were made in 47 dwellings over three to five months, covering the two typical seasons, to estimate the internal doses. Atmospheric radon gases were simultaneously collected at several heights to evaluate the vertical distribution. The absorbed dose rates in air in the study area vary widely between 50 nGy h$$^{-1}$$ and 1109 nGy h$$^{-1}$$. Indoor radon concentrations ranged from 124 Bq m$$^{-3}$$ to 1015 Bq m$$^{-3}$$. That is, the indoor radon concentrations measured exceed the reference levels of 100 Bq m$$^{-3}$$ recommended by the World Health Organization. Furthermore, the outdoor radon concentrations measured were comparable to the high indoor radon concentrations. The annual effective dose due to external and internal exposures in the study area was estimated to be 27 mSv using the median values. It was found that many residents are receiving radiation exposure from natural radionuclides over the dose limit for occupational exposure to radiation workers. This enhanced outdoor radon concentration might be as a result of the stable atmospheric conditions generated at an exceptionally low altitude. Our findings suggest that this area provides a unique opportunity to conduct an epidemiological study related to health effects due to chronic low dose-rate radiation exposure.

Journal Articles

Development of dose estimation system integrating sediment model for recycling radiocesium-contaminated soil to coastal reclamation

Miwa, Kazuji; Takeda, Seiji; Iimoto, Takeshi*

Radiation Protection Dosimetry, 184(3-4), p.372 - 375, 2019/10

 Times Cited Count:0 Percentile:0.01(Environmental Sciences)

The Ministry of the Environment has indicated the policy of recycling the contaminated soil generated by decontamination activity after the Fukushima accident. By recycling to coastal reclamation which is one of effective recycling application, dissolved radiocesium and absorbed radiocesium on soil particles will flow out to the ocean by construction, therefore evaluating radiocesium transition in ocean considering the both types of radiocesium is important for safety assessment. In this study, the radiocesium outflow during constructing and after constructing is modeled, and radiocesium transition in ocean is evaluated by Sediment model suggested in OECD/NEA. The adaptability of sediment model is confirmed by reproducing evaluation of the coastal area of Fukushima. We incorporate the sediment model to PASCLR2 code system to evaluate the doses from radiocesium in ocean.

Journal Articles

Investigation on the influence of additional protective measures on sheltering effectiveness for internal exposure

Hirouchi, Jun; Takahara, Shogo; Komagamine, Hiroshi*; Munakata, Masahiro

Proceedings of Asian Symposium on Risk Assessment and Management 2019 (ASRAM 2019) (USB Flash Drive), 7 Pages, 2019/09

no abstracts in English

Journal Articles

Investigation of reduction factor of internal exposure for sheltering in Japan

Hirouchi, Jun; Takahara, Shogo; Komagamine, Hiroshi*; Munakata, Masahiro

Proceedings of Asian Symposium on Risk Assessment and Management 2018 (ASRAM 2018) (USB Flash Drive), 8 Pages, 2018/10

no abstracts in English

Journal Articles

Challenges for enhancing Fukushima environmental resilience, 10; Dose evaluation and risk communication

Saito, Kimiaki; Takahara, Shogo; Uezu, Yasuhiro

Nihon Genshiryoku Gakkai-Shi ATOMO$$Sigma$$, 60(2), p.111 - 115, 2018/02

no abstracts in English

Journal Articles

Factors affecting the effectiveness of sheltering in reducing internal exposure

Hirouchi, Jun; Takahara, Shogo; Komagamine, Hiroshi*; Watanabe, Masatoshi*; Munakata, Masahiro

Proceedings of Asian Symposium on Risk Assessment and Management 2017 (ASRAM 2017) (USB Flash Drive), 11 Pages, 2017/11

no abstracts in English

JAEA Reports

Nuclear Decay Data for Dosimetry Calculation; Revised data of ICRP Publication 38

Endo, Akira; Yamaguchi, Yasuhiro; Eckerman, K. F.*

JAERI 1347, 114 Pages, 2005/02

JAERI-1347.pdf:6.57MB

no abstracts in English

Journal Articles

Development and assessment of new radioactive decay database used for dosimetry calculation

Endo, Akira; Yamaguchi, Yasuhiro; Eckerman, K. F.*

Radiation Protection Dosimetry, 105(1-4), p.565 - 569, 2003/09

 Times Cited Count:11 Percentile:61.24(Environmental Sciences)

The present paper discusses a strategy for the development of a new radioactive decay database, which will succeed ICRP Publ.38 used for dosimetry calculations. The development of the database requires 1) Consistency checking of the ENSDF used for compilation of the decay data, 2) Improvement of the computer code EDISTR for processing the ENSDF, and 3) Comparison with other decay data prepared from the different computer codes and libraries for the verification of the compiled data. This paper identifies several technical issues that need to be addressed for the development of the new radioactive decay database.

Journal Articles

Study of particle size distribution and formation mechanism of radioactive aerosols generated in high-energy neutron fields

Endo, Akira; Sato, Kaoru; Noguchi, Hiroshi; Tanaka, Susumu; Iida, Takao*; Furuichi, Shinya*; Kanda, Yukio*; Oki, Yuichi*

Journal of Radioanalytical and Nuclear Chemistry, 256(2), p.231 - 237, 2003/05

 Times Cited Count:6 Percentile:43.28(Chemistry, Analytical)

Size distributions of $$^{38}$$Cl, $$^{39}$$Cl, $$^{82}$$Br and $$^{84}$$Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45MeV and 65MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive particles in high energy radiation fields. Effects of the size distribution of the radioactive aerosols on the size of added DOP aerosols, the energy of irradiation neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols.

JAEA Reports

Dose coefficients for radionuclides produced in high energy proton accelerator facilities; Coefficients for radionuclides not listed in ICRP publications

Kawai, Katsuo; Endo, Akira; Noguchi, Hiroshi

JAERI-Data/Code 2002-013, 66 Pages, 2002/05

JAERI-Data-Code-2002-013.pdf:2.75MB
JAERI-Data-Code-2002-013-DoseCD.pdf:81.85MB

Effective dose coefficients by inhalation and ingestion have been calculated for 334 nuclides, including (1) nuclides with half-lives $$ge$$ 10min and their daughters that are not listed in ICRP Publications and (2) nuclides with half-lives $$<$$ 10min that are produced in a spallation target. Dose calculation was carried out using a nuclear decay database DECDC and a decay data library newly compiled from the ENSDF. The dose coefficients were calculated with the computer code DOCAP based on the respiratory tract model and biokinetic model of ICRP. The calculated results are presented as tables, which are the same forms as those in ICRP Publs.68 and 72. The complete listings of the dose coefficients are arranged on a CD-ROM, DoseCD, as indexed tables for inhalation of ten particle sizes, ingestion and injection into blood for workers and members of the public. The dose coefficients calculated in the present study are useful to calculate internal doses for a variety of radionuclides produced in high energy proton accelerator facilities.

JAEA Reports

Compilation of nuclear decay data used for dose calculation; Revised data for radionuclides listed in ICRP publication 38

Endo, Akira; Yamaguchi, Yasuhiro

JAERI-Data/Code 2001-004, 157 Pages, 2001/03

JAERI-Data-Code-2001-004.pdf:11.27MB

New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ.38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are important for calculating energies and intensities of emissions were updated by referring to NUBASE. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of $$alpha$$ particles, $$beta$$ particles, $$gamma$$ rays, internal conversion electrons, X rays, and Auger electrons. The compiled data were prepared in two different types of format: Publ.38 and NUCDECAY formats. The decay data will be widely used for dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ.38.

Journal Articles

Airborne gaseous $$^{13}$$N species and noxious gases produced at the 12GeV proton synchrotron

Kanda, Yukio*; Oki, Yuichi*; Endo, Akira; Numajiri, Masaharu*; Kondo, Kenjiro*

Journal of Radioanalytical and Nuclear Chemistry, 247(1), p.25 - 31, 2001/01

 Times Cited Count:9 Percentile:57.68(Chemistry, Analytical)

no abstracts in English

Journal Articles

Evaluation of internal and external doses from $$^{11}$$C produced in the air in high energy proton accelerator tunnels

Endo, Akira; Oki, Yuichi*; Kanda, Yukio*; Oishi, Tetsuya; Kondo, Kenjiro*

Radiation Protection Dosimetry, 93(3), p.223 - 230, 2001/00

 Times Cited Count:6 Percentile:45.58(Environmental Sciences)

no abstracts in English

Journal Articles

Reassessment and reinforcement of nuclear decay database used for dose calculations

Endo, Akira; Yamaguchi, Yasuhiro

Proceedings of 10th International Congress of the International Radiation Protection Association (IRPA-10) (CD-ROM), 8 Pages, 2000/05

no abstracts in English

Journal Articles

Characterization of $$^{11}$$C, $$^{13}$$N and $$^{15}$$O produced in air through nuclear spallation reactions by high energy protons

Endo, Akira; Oki, Yuichi*; Kanda, Yukio*; Kondo, Kenjiro*

Proceedings of 10th International Congress of the International Radiation Protection Association (IRPA-10) (CD-ROM), 8 Pages, 2000/05

no abstracts in English

JAEA Reports

Health Physics in JAERI, No.41; April 1, 1998 - March 31, 1999

Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Utilities and Safety Division, Kansai; Operation Safety Administration Division, Mutsu

JAERI-Review 2000-001, p.225 - 0, 2000/03

JAERI-Review-2000-001.pdf:9.42MB

no abstracts in English

JAEA Reports

Dose coefficients for intakes of radionuclides by workers; Coefficients for radionuclides not listed in ICRP Publication 68

Endo, Akira; Yamaguchi, Yasuhiro

JAERI-Data/Code 99-047, p.24 - 0, 1999/12

JAERI-Data-Code-99-047.pdf:0.88MB

no abstracts in English

JAEA Reports

Compilation of nuclear decay data used for dose calculations; Data for radionuclides not listed in ICRP Publication 38

Endo, Akira; *; Yamaguchi, Yasuhiro

JAERI-Data/Code 99-035, 355 Pages, 1999/07

JAERI-Data-Code-99-035.pdf:14.77MB

no abstracts in English

Journal Articles

Comparison of nuclear decay data derived from recent nuclear structure data files with those of ICRP publication 38

Endo, Akira; Yamaguchi, Yasuhiro

Radiation Protection Dosimetry, 82(1), p.59 - 64, 1999/00

 Times Cited Count:2 Percentile:21.95(Environmental Sciences)

no abstracts in English

34 (Records 1-20 displayed on this page)