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Yamagishi, Isao; Hato, Shinji*; Nishihara, Kenji; Tsubata, Yasuhiro; Sagawa, Yusuke*
JAEA-Data/Code 2024-002, 63 Pages, 2024/07
Adsorption columns filled with zeolite are used to treat contaminated water containing radioactive cesium generated by the Fukushima Daiichi Nuclear Power Station accident. As the contaminated water treatment progresses, the radioactive cesium in the adsorption column becomes highly concentrated, and the adsorption column becomes a high radiation source. To evaluate the radiation effects such as decay heat and radiolytic hydrogen production in the adsorption column, the concentration of radioactive cesium in the adsorption column is necessary, but since it is difficult to evaluate the concentration by measurement, it is estimated by simulation. In this research, a zeolite column adsorption dynamics simulation (Zeolite Adsorption Column: ZAC) code was developed to calculate the concentration of radioactive materials such as radioactive cesium in a zeolite filled adsorption column when they are injected into the column. The code was validated through comparison of calculation results with existing codes and experimental results of small column tests. This report presents the details of the model, the handling of the code, and the validity of the results for the developed code.
Kimura, Masanori; Munakata, Masahiro; Hato, Shinji*; Kanno, Mitsuhiro*
JAEA-Data/Code 2020-002, 38 Pages, 2020/03
To consider the method of implementing urgent protective actions in a nuclear accident appropriately, the authors have been assessing the effects of reducing doses by taking urgent protective actions using a Level 3 Probabilistic Risk Assessment (PRA) code, the OSCAAR, developed by the JAEA. Iodine thyroid blocking is an effective urgent protective action to reduce equivalent doses to the thyroid due to inhalation of radioactive iodine. However, the timing of the administration of stable iodine (SI) is important to maximize the effectiveness for thyroidal blocking. Therefore, the careful consideration should be given to the most effective way of iodine thyroid blocking when preparing off-site emergency plans. In the present study, the authors developed a new metabolic model for thyroid by combining the respiratory tract model (Publ.66) and gastrointestinal tract model (Publ.30) of the ICRP with a metabolic model for thyroid (Johnson's model) in order to calculate the behavior of radioiodine and stable iodine in the body more realistically. The model is useful to evaluate the effect of the administration of SI for reducing equivalent doses to the thyroid depending on the its timing. We also calculated the reduction factor for equivalent doses to the thyroid in order to the thyroid by using the model, and then developed the its database for the OSCAAR. Consequently, the OSCAAR can evaluate the effectiveness for thyroidal blocking realistically and promptly.
Kimura, Masanori; Hato, Shinji*; Matsubara, Takeshi*; Kanno, Mitsuhiro*; Munakata, Masahiro
Proceedings of Asian Symposium on Risk Assessment and Management 2017 (ASRAM 2017) (USB Flash Drive), 9 Pages, 2017/11
The authors developed a new metabolic model for iodine by combining the respiratory tract model (Publ.66), the gastrointestinal tract model (Publ.30) of the ICRP and the metabolic model for iodine (Johnson's model) in order to evaluate the behavior of radioiodine and stable iodine in the body more realistically. The developed metabolic model indicated that a reduction factor (RF) depends on dosage of stable iodine, timing of the administration of stable iodine, different iodine isotopes (I - I), and age groups. Therefore, the RF was calculated by changing these parameters and then a database of the RF was constructed for the application to the OSCAAR code.
Pratama, M. A.; Takahara, Shogo; Hato, Shinji*
Hoken Butsuri, 52(3), p.200 - 209, 2017/09
The purpose of this study is to identify the significance of the change in the intestinal absorption rate values the ( value) to the change of dose coefficient as well as to provide a list of dose coefficients which each of the value corresponds to a specific intestinal absorption rate and age groups. In the range of 0-1, 10 different values of for 1 year, 5 years old, and adult group were chosen and used in a separate calculation by using, a biokinetic compartment model, DCAL. It was found that the lower values of intestinal absorption rate lead to a significant decrease of the committed effective coefficient for adult. Oppositely for children, the decrease of committed effective coefficient was not as significant. This study also suggests that the significance of dose coefficient change due to the variation of substantially depends on the biological half-life of the radionuclide and the mass of organs and tissues in human body.
Hato, Shinji*; Kinase, Sakae
Nihon Genshiryoku Gakkai Wabun Rombunshi, 15(3), p.146 - 150, 2016/09
Hato, Shinji*; Kinase, Sakae; Kimura, Masanori
Progress in Nuclear Science and Technology (Internet), 4, p.36 - 38, 2014/04
Kinase, Sakae; Kimura, Masanori; Hato, Shinji*
Progress in Nuclear Science and Technology (Internet), 4, p.5 - 8, 2014/04
Kimura, Masanori; Kinase, Sakae; Hato, Shinji*
Progress in Nuclear Science and Technology (Internet), 4, p.60 - 63, 2014/04
Kimura, Masanori; Kinase, Sakae; Hato, Shinji*
JAEA-Data/Code 2012-027, 27 Pages, 2013/02
The Fukushima Daiichi Nuclear Power Plant accident resulted in a wide range of radioactive contamination. As a result, the public concerns the internal doses for chronic exposure due to intake in daily life. To reduce some concerns, it is important to develop the evaluation method of chronic internal dose. The JAEA developed the DSYS code that calculates internal dose to the public with dose coefficients and treats dose assessment of internal exposure due to acute intake based on the ICRP's Publications (Publ.30, 56, 66, 67, 69, 71, 72). Therefore, it cannot apply to the evaluation of whole-body retention values or committed effective/equivalent dose for chronic exposure. In the present study, the authors considered the evaluation method of chronic internal dose and developed the DSYS-Chronic to evaluate chronic internal dose by incorporating into the DSYS code. This report shows the outline of the DSYS-Chronic code and the example of evaluation results.
Kinase, Sakae; Kimura, Masanori; Hato, Shinji*
Proceedings of International Symposium on Environmental monitoring and dose estimation of residents after accident of TEPCO's Fukushima Daiichi Nuclear Power Station, 4 Pages, 2012/12
Tamura, Junji*; Kido, Hiroko*; Hato, Shinji; Homma, Toshimitsu
JAEA-Research 2008-103, 94 Pages, 2009/03
The plume models are used in probabilistic accident consequence assessment (PCA) codes due to cost and time savings. The PCA code, OSCAAR developed by JAERI (Present; JAEA) uses the puff model to calculate atmospheric transport and dispersion. In order to investigate uncertainties involved with the structure of the atmospheric dispersion/deposition model in OSCAAR, we have introduced the more sophisticated computer codes that included regional meteorological model RAMS and atmospheric transport model HYPACT, and comparative analyses between OSCAAR and RAMS/HYPACT have been performed. In this study, model verification of OSCAAR and RAMS/HYPACT was conducted using data of long term atmospheric diffusion experiments, which were carried out in Tokai-mura, Ibaraki-ken. The predictions by models and the results of the atmospheric diffusion experiments indicated relatively good agreements. And it was shown that model performance of OSCAAR was the same degree as it of RAMS/HYPACT.
Hato, Shinji; Terakado, Masato*; Tomita, Kenichi*; Homma, Toshimitsu
JAEA-Data/Code 2008-031, 75 Pages, 2009/03
This is the user's manual of DSYS-GUI, which calculates the internal dose coefficients by the models of International Commission on Radiological Protection (ICRP). The DSYS-GUI consists of two programs. One is a program for setting calculation conditions and executing. The other is a program for displaying results to figures and tables. The displaying them are used the Microsoft Excel. Anyone can easily calculate the internal dose coefficients and quickly display results as figures and tables with DSYS-GUI.
Hato, Shinji; Homma, Toshimitsu
JAEA-Research 2008-094, 95 Pages, 2009/02
The atmospheric diffusion experiments were implemented by Japan Atomic Energy Research Institute (JAERI) around Mount Tsukuba in 1989 and 1990, and the tracer gas concentration were monitored. In this study, the Gauss Plume Model and RAMS/HYPACT that are meteorological forecast code and atmospheric diffusion code with detailed physical law are made a comparison between monitored concentration. In conclusion, the Gauss Plume Model is better than RAM/HYPACT even complex topography if the release is around release point and short estimation. This reason is difference of wind between RAMS and observation.
Kimura, Masanori; Hato, Shinji
Nihon Hoken Butsuri Gakkai Senmon Kenkyukai Hokokusho Shirizu (Internet), 6(2), p.36 - 42, 2008/04
no abstracts in English
Kurihara, Osamu; Hato, Shinji; Kanai, Katsuta; Takada, Chie; Takasaki, Koji; Ito, Kimio; Ikeda, Hiroshi*; Oeda, Mikihiro*; Kurosawa, Naohiro*; Fukutsu, Kumiko*; et al.
Journal of Nuclear Science and Technology, 44(10), p.1337 - 1346, 2007/10
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)In the case of internal contamination of radionuclides, it is necessary to perform internal dose assessment for radiation protection. For this purpose, the ICRP has given the dose coefficients and the retention and excretion rates for various radionuclides. However, these dosimetric quantities are calculated only in typical conditions, therefore, are not necessarily covered enough in the case of dose assessment in which specific information on the incident or/and individual biokinetic characteristics should be taken into account retrospectively. This paper describes a developed PC-based package of software REIDAC to meet the needs in retrospective dose assessment. REIDAC was verified by comparisons with dosimetric quantities given on the ICRP publications and several examples of practical use were also shown.
Hato, Shinji; Homma, Toshimitsu
RIST News, (41), p.33 - 41, 2006/05
no abstracts in English
Hato, Shinji*; Homma, Toshimitsu
JAERI-Data/Code 2005-006, 549 Pages, 2005/09
The OSCAAR computer code for use in probabilistic accident consequence assessment (Level3PSA) developed at JAERI has calculated dose to the public with internal dose conversion factors based on dosimetric models and biokinetic data provided in ICRP Publication 30. Since ICRP issued age-dependent biokinetic models for a limited set of radioisotopes as ICRP Publication 56, a new Human Respiratory Tract model, age-dependent biokinetic model for other radioisotopes and urinary and faecal excretion models were issued. ICRP has published age-dependent internal dose coefficients for a large set of radionuclides in its publications, but they provided only committed effective dose coefficients for inhalation and ingestion. Since OSCAAR estimated acute and late health effects for public, it needs internal dose coefficients for specific tissues and organs in arbitrary integration times.This report describes a code DSYS developed for calculating dose coefficients based on these new ICRP models. It also provides the internal dose coefficients for 54 radionuclides used in OSCAAR calculations.
Homma, Toshimitsu; Tomita, Kenichi*; Hato, Shinji*
Nuclear Engineering and Technology, 37(3), p.245 - 258, 2005/06
This paper addresses two types of uncertainty: stochastic uncertainty and subjective uncertainty in probabilistic accident consequence assessments. The off-site consequence assessment code OSCAAR has been applied to uncertainty and sensitivity analyses on the individual risks of early fatality and latent cancer fatality in the population due to a severe accident. A new stratified meteorological sampling scheme was successfully implemented into the trajectory model for atmospheric dispersion and the statistical variability of the probability distributions of the consequence was examined. A total of 65 uncertain input parameters was considered and 128 runs of OSCAAR were performed in the parameter uncertainty analysis. The study provided the range of uncertainty for the expected values of individual risks of early and latent cancer fatality close to the site. In the sensitivity analyses, the correlation/regression measures were useful for identifying those input parameters whose uncertainty makes an important contribution to the overall uncertainty for the consequence.
Hato, Shinji*; Homma, Toshimitsu
no journal, ,
Kimura, Masanori; Kinase, Sakae; Hato, Shinji*
no journal, ,
no abstracts in English