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Sanada, Yukihisa; Yoshimura, Kazuya; Sato, Rina; Nakayama, Mariko*; Tsubokura, Masaharu*
Journal of Radiation Research (Internet), 64(1), p.2 - 10, 2023/01
Times Cited Count：0 Percentile：0.06(Biology)The evacuation orderareas established due to the accident at the Tokyo Electric Power Company Holdings' (TEPCO) Fukushima Daiichi Nuclear Power Plant (FDNPP) have been reorganized according to the decrease in ambient dose rates and the decontamination progress. The Japanese government decided to decontaminate the difficult-to-return areas and lift the evacuation order by 2030. This radiation protection strategy can be optimized by examining emergency exposure situations to date and the existing exposure after the accident. This article reviews the methods that can determine the individual radiation doses of residents who should return to their homes when the evacuation order is lifted in the specific reconstruction reproduction base area and the difficult-to-return areas outside this base area and summarizes the points to be considered when implementing these methods. In Part 1 of this article, we review the efforts made by the Japanese government and research institutes to assess radiation doses to residents after the FDNPP accident.
Takahashi, Tomoyuki*; Uchida, Shigeo*; Takeda, Seiji; Nakai, Kunihiro*
KURNS-EKR-11, p.97 - 102, 2021/03
This paper outlines the status of IAEA database compilation for migration parameters depending elements in a biosphere such as soil-to-plant transfer factor and bioconcentration factor of marine products, and the status of utilization of the database in dose evaluation of radioactive waste disposal in Japan. Additionally, in the case of applying a new database to the dose evaluation for future radioactive waste disposal in a specific area. We summarized the opinions of specialists and result of general discussion about future strategies to make a new database for their parameters, perspectives to be considered in it, issues, etc.
Uezu, Yasuhiro
Iwaki-Shi, Higashi Nihon Daishinsai Fukko Kiokushu, P. 37, 2021/00
This report describes the response to the Great East Japan Earthquake that occurred on March 11, 2011 from the perspectives of environmental monitoring, internal exposure evaluation, radiation education, and human resource development.
Sr in urine sample; Rapid separation of Sr by phosphate co-precipitation and extraction chromatography, followed by determination by triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS)Tomita, Jumpei; Takeuchi, Erina
Applied Radiation and Isotopes, 150, p.103 - 109, 2019/08
Times Cited Count：14 Percentile：82.61(Chemistry, Inorganic & Nuclear)A rapid analytical method for determining Sr in urine samples (1-2 L) was developed to assess the internal exposure of workers in a radiological emergency. Strontium in a urine sample was rapidly separated by phosphate co-precipitation, followed by extraction chromatography with a tandem column of Pre-filter, TRU and Sr resin, and the Sr activity was determined by ICP-MS/MS. Measurement in the MS/MS mode with an O
reaction gas flow rate 1 mL min
showed no tailing of 
Sr at m/z = 90 up to 50 mg-Sr L. The interferences of Ge, Se and Zr at m/z = 90 were successfully removed by chemical separation. This analytical method was validated by the results of the analyses of synthetic urine samples (1.2-1.6 L) containing a known amount of Sr along with 1 mg of each of Ge, Se, Sr and Zr. The turnaround time for analysis was about 10 h, and the detection limit of Sr was approximately 1 Bq per urine sample.
C accumulated in vegetation around a nuclear facility; Application of a sophisticated land surface C model to the Rokkasho reprocessing plant, JapanOta, Masakazu; Katata, Genki; Nagai, Haruyasu; Terada, Hiroaki
Journal of Environmental Radioactivity, 162-163, p.189 - 204, 2016/10
Times Cited Count：7 Percentile：22.36(Environmental Sciences)Impacts of plant C uptake on (C) distributions around a nuclear facility were investigated by a land surface C model (SOLVEG-II). The simulation combined the SOLVEG-II with a mesoscale model and an dispersion model was applied to CO transfer at test operations of the Rokkasho reprocessing plant (RRP) in 2007. The calculated C-specific activities in rice grains agreed with the observations. Numerical experiment of chronic CO release from the RRP showed that C-specific activities of rice plants at harvest differed from the annual mean ones in the air, which was attributed to seasonal variations in atmospheric CO and plant growth. C accumulation in plant significantly increased when CO releases were limited during daytime, compared with the results observed during nighttime, due to extensive CO uptake by daytime photosynthesis. These results indicated that plant growth and photosynthesis should be considered in predictions of ingestion dose of C for long-term chronic and short-term diurnal releases of CO, respectively.
Tsujimoto, Kazufumi; Tazawa, Yujiro; Oigawa, Hiroyuki; Sasa, Toshinobu; Takano, Hideki
JAERI-Tech 2003-085, 158 Pages, 2003/11
JAERI-Tech-2003-085.pdf:7.79MB
A safety analysis was performed for the Transmutation Physics Experiment Facility which was to research and develop the reactor physics aspects of the nuclear transmutation technology using the accelerator driven subcritical system. Design policies were evaluated for design of each equipment and system which had important role from view point of safety. Classification of safety class for reactor building, system, and equipment was also reconsidered. Based on the results of safety design policy, acceptance criteria for safety evaluation were reestablished and preliminary analysis were performed. Public exposure by the accident for site appropriateness assessment was evaluated based on revised guidelines in safety evaluation contained in the 1990 Recommendations of ICRP. A recritical event was analyzed by utilizing the newest knowledge for core disruptive accident and calculation code as the beyond design basis accident. The analytical results showed that the isolation capability of the container buildings was ensured against the recritical accident.
Homma, Toshimitsu; Takahashi, Tomoyuki*; Togawa, Orihiko
Hoken Butsuri, 36(4), p.308 - 313, 2001/12
no abstracts in English
Endo, Akira
Nihon Genshiryoku Gakkai-Shi, 43(12), p.1191 - 1194, 2001/12
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Nuclear decay data, a set of data on half-life and energies and intensities of radiations emitted by nuclear transformation, are required in calculating external and internal doses by emissions from radionuclides. A nuclear decay database, which has been the most widely used for dose calculation in radiation protection, is Publication 38 (ICRP38) of the International Commission on Radiological Protection. The paper describes overview of ICRP38 and a future plan of its revision.
Okoshi, Minoru
KURRI-KR-56, p.39 - 57, 2001/03
no abstracts in English
Harada, Yasunori; Sasamoto, Nobuo; Sakamoto, Yukio; Kurosawa, Naohiro*; *
JAERI-Data/Code 97-013, 196 Pages, 1997/03
JAERI-Data-Code-97-013.pdf:4.59MB
no abstracts in English
Furuta, Sadaaki; Ikeda, Koki; Mikake, Shinichiro; Imaeda, Yasuhiro; Nagasaki, Yasushi; Suzuki, Hajime; Nomura, Yukihiro
no journal, ,
no abstracts in English
Nakamura, Makoto; Tobita, Kenji; Tanigawa, Hisashi; Someya, Yoji; Masui, Akihiro; Watanabe, Kazuhito; Konishi, Satoshi*; Torikai, Yuji*
no journal, ,
Tritium is major radioactive material in a fusion reactor. Evaluation of the dose due to the tritium is essential to understand environmental consequences of incidental or accidental conditions postulated in the fusion reactor. A purpose of this study is to identify issues to apply UFOTRI, a code of tritium dose analysis being used for the ITER safety assessment, the Japanese environmental conditions. Extensive scans of UFOTRI calculation runs were performed in various meteorological and release conditions. The scans show that the contribution of the secondary tritium release is more significant in the cases of lower release height, lesser stable atmosphere or more distant conditions. The analysis, thus, suggests that it is important to take into account the contribution of the secondarily released tritium in evaluating the early dose to the public due to the tritium release.
Sato, Tetsuro*; Ando, Masaki; Saito, Kimiaki
no journal, ,
The life behavior patterns and the path expected when the residents returned to the evacuation order release preparation area were investigated through interviews, and the air dose rates over the path measured with KURAMA-II. The results of expectation of exposure dose received in daily life when the residents returned to the areas showed that the minimum value of the additional exposure dose of a year was 0.31[mSv] and the maximum one was 2.62[mSv], and that the additional exposure dose of a year for 47 people which is 72% of the subject 65 people was less than 1.0[mSv].
Terada, Hiroaki; Nagai, Haruyasu
no journal, ,
no abstracts in English
Terada, Hiroaki; Nagai, Haruyasu
no journal, ,
For the assessment of the radiological doses to the public due to the atmospheric discharge of radioactive materials during the Fukushima Daiichi Nuclear Power Station accident, the spatiotemporal distribution of radioactive materials in the environment are reconstructed by atmospheric dispersion simulation with the improved WSPEEDI. In this study, the influence of chemical form of 
I (particle, inorganic and organic gas) in source term on the simulated results was analyzed to assess the uncertainty of the simulation. From the sensitivity test with the chemical form composition, surface deposition distribution of I was influenced according to the property of the chemical forms to deposition processes, whereas time-integrated air concentration was less influenced. From the comparison with the measurement, the surface deposition simulated with the source term in Katata et al. (2015) had a good reproducibility compared with those with extreme gas to particle ratios.
Miwa, Kazuji; Shimada, Taro; Takeda, Seiji
no journal, ,
In this study, in order to validate the restricted use of recycling material at the reference radiocesium concentration (determined in series report (1)), we evaluated worker annual doses, air dose rate at the site boundary and impact of migrated radiocesium into groundwater. Firstly, we evaluated the additional annual dose for workers, on the assumption that typical workers coming in contact with the source after construction (Road: 1.3 mSv/y, Building: 1.3 mSv/y). Secondly, we evaluated the air dose rates by distance from road and building including recycling material, and investigated the distance for not exceeding 1mSv/y (including additional dose rate by recycling and background dose rate of 0.6 mSv/y) at the site boundary (Road: 25 m, Building: 1 m). Thirdly, we evaluated the Cs and Sr migration in groundwater, and investigated the distance required for satisfying the operation target value (Cs-134: 1 Bq/L, Cs-137: 1 Bq/L, Sr-90: 5 Bq/L) at the boundary (coastal line) (Road: 10 m, Building: 10 m).
Terada, Hiroaki; Nagai, Haruyasu
no journal, ,
no abstracts in English
Matsushima, Akira; Hayashi, Hirokazu
no journal, ,
no abstracts in English
Miwa, Kazuji; Namekawa, Masakazu*; Shimada, Taro; Takeda, Seiji
no journal, ,
For development of technical foundation to confirm the completion of the decommissioning of nuclear facilities, JAEA is developing the methodology to evaluate the dose in considering radionuclides migration by not only groundwater migration but also surface water migration and surface soil migration. We studied estimating methods for radionuclide migration between the surface water and surface contaminated soil, changes of radionuclide distribution, and direct outflow of radionuclides to the sea. In addition, preliminary analysis of the surface water migration and soil migration based on the topography and rainfall conditions is performed by using a general-purpose water and soil runoff evaluation code. The methodology will be applied to evaluate the dose by using the out put of the surface water migration and soil migration.
Sanada, Yukihisa
no journal, ,
Since immediately after the accident, JAEA has been conducting environmental monitoring and research on the dynamics of microscopic radioactive materials in the environment. based on the radiation protection policy at the specific reconstruction and revitalization sites decided by the government since 2016, JAEA has been developing detailed environmental monitoring techniques, exposure assessment based on monitoring results, and monitoring results and We have contributed to the lifting of the Specific Reconstruction and Revitalization Bases by applying technologies that package the information disclosure of exposure assessment tools. In this presentation, we will report on the details of the technology package applied to such Specific Reconstruction and Revitalization Sites.
