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Kataoka, Takahiro*; Naoe, Shota*; Murakami, Kaito*; Yukimine, Ryohei*; Fujimoto, Yuki*; Kanzaki, Norie; Sakoda, Akihiro; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*
Journal of Clinical Biochemistry and Nutrition, 70(2), p.154 - 159, 2022/03
Times Cited Count：3 Percentile：57.52(Nutrition & Dietetics)Collaborative Laboratories for Advanced Decommissioning Science; Okayama University*
JAEA-Review 2021-028, 57 Pages, 2021/11
JAEA-Review-2021-028.pdf:1.94MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Interdisciplinary evaluation of biological effect of internal exposure by inhaling alpha-ray emitting nuclides represented by radon" conducted from FY2018 to FY2020. Since the final year of this proposal was FY2020, the results for three fiscal years were summarized. The present study aims to evaluate the influence of radiation exposure to alpha-ray emitting dusts generated in decommissioning of the nuclear reactors. Radon is used here as a surrogate nuclide because it is an alpha-ray emitter and there have been extensive studies on it so far.
Kataoka, Takahiro*; Shuto, Hina*; Naoe, Shota*; Yano, Junki*; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Hanamoto, Katsumi*; Mitsunobu, Fumihiro*; Terato, Hiroaki*; et al.
Journal of Radiation Research (Internet), 62(5), p.861 - 867, 2021/09
Times Cited Count：5 Percentile：55.27(Biology)Aoki, Katsunori; Yamanaka, Hiroki*; Watanabe, Kazuhiko*; Sugihara, Kozo
JAEA-Data/Code 2020-018, 45 Pages, 2021/02
JAEA-Data-Code-2020-018.pdf:4.54MB
JAEA-Data-Code-2020-018-appendix(DVD-ROM).zip:6.8MB
Mizunami Underground Research Laboratory (MIU) Project is pursued by Japan Atomic Energy Agency (JAEA) in the crystalline host rock (granite) as a part of geoscientific study of JAEA, and underground facilities of MIU are constructed down to 500m blow the ground surface. As small amount of Uranium is normally contained in granite, high concentration of radon is sometimes detected in the air of the underground facilities constructed in granitic rocks depending on their ventilation conditions. Radon concentrations in underground facilities of MIU have been measured according to the excavation progress of underground facilities or the change of ventilation system. It is recognized that the data obtained by the actual measurement of radon concentration in such underground facilities are rare and valuable. This repot summarizes the measured data from fiscal 2010 to fiscal 2020, together with the information of ventilation conditions and air temperature which affect radon concentrations in underground facilities. The variation of the equilibrium factors of radon is also examined with the actually measured data. As a result, it has been found that radon concentration in the drift is high in summer and low in winter according to the natural ventilation caused by the seasonal temperature difference between in and out of the underground facilities. Furthermore, the temporary increase in the equilibrium factor of radon in the drift at the start of ventilation is supposed to be due to the aerosol increase by the ventilation flow, such as the dust blown up.
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：23 Percentile：86.19(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
and 1109 nGy h. Indoor radon concentrations ranged from 124 Bq m
to 1015 Bq m. That is, the indoor radon concentrations measured exceed the reference levels of 100 Bq m 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.
Collaborative Laboratories for Advanced Decommissioning Science; Okayama University*
JAEA-Review 2020-029, 55 Pages, 2020/12
JAEA-Review-2020-029.pdf:2.08MB
JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2018, this report summarizes the research results of the "Interdisciplinary Evaluation of Biological Effect of Internal Exposure by Inhaling Alpha-ray Emitting Nuclides Represented by Radon" conducted in FY2019.
Saito, Tatsuo; Kobayashi, Shinichi*; Zaitsu, Tomohisa*; Shimo, Michikuni*; Fumoto, Hiromichi*
Hoken Butsuri (Internet), 55(2), p.86 - 91, 2020/06
Safety cases for disposal of uranium bearing waste and NORM with uranium has not yet been fully developed in Japan, because of safety assessment of extraordinary long timespan and uncertainty in unexpected incidents with uncompleted radon impact evaluation measures arising from uranium waste disposal facility in far future. Our task group of radiation protection for wastes with natural radioactive nuclides studied some safety cases with disposal of uranium bearing waste and NORM in terms of nuclides, U-235, U-238 and their progenies, and comprehensively discussed the current state of their disposal in comparison to the ideas of international organizations such as ICRP and IAEA. We developed our ideas for long term uncertainty and radon with the knowledge of experts in each related area of direction, repeating discussions, focusing out the orientation of each directions, and outlined the recommendations with our suggestions of solving important issues in the future to be addressed.
Collaborative Laboratories for Advanced Decommissioning Science; Okayama University*
JAEA-Review 2019-024, 61 Pages, 2020/01
JAEA-Review-2019-024.pdf:2.22MB
CLADS, JAEA, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Interdisciplinary Evaluation of Biological Effect of Internal Exposure by Inhaling Alpha-ray Emitting Nuclides Represented by Radon". In the present study, the effect of alpha-ray emission in human body on the surrounding cells is estimated, and biological response to alpha-ray exposure is investigated at the whole organism level, by the evaluation method for radiation effects using radon that is an alpha-ray emitting nuclide, because there have been extensive studies on radon so far. From the obtained results, a model to evaluate the effect of internal exposure by alpha-ray emitting nuclides on health is constructed. Through these studies, we aim to form a research base by the interdisciplinary organic collaboration among research organizations.
Etani, Reo*; Kataoka, Takahiro*; Kanzaki, Norie*; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro*; Taguchi, Takehito*; Yamaoka, Kiyonori*
Journal of Radiation Research, 58(5), p.614 - 625, 2017/05
Times Cited Count：13 Percentile：53.9(Biology)Radon therapy using radon (
Rn) gas is classified into two types of treatment: inhalation of radon gas and drinking water containing radon. Although short- or long-term intake of spa water is effective in increasing gastric mucosal blood flow, and spa water therapy is useful for treating chronic gastritis and gastric ulcer, the underlying mechanisms for and precise effects of radon protection against mucosal injury are unclear. In the present study, we examined the protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice. Mice inhaled radon at a concentration of 2000 Be/m
for 24 h or were provided with hot spring water for 2 weeks. The activity density of Rn ranged from 663 Bq/l (start point of supplying) to 100 Bq/l (end point of supplying).Mice were then orally administered ethanol at three concentrations. The ulcer index (UI), an indicator of mucosal injury, increased in response to the administration of ethanol; however, treatment with either radon inhalation or hot spring water inhibited the elevation in the UI due to ethanol. Although no significant differences in antioxidative enzymes were observed between the radon-treated groups and the non-treated control groups, lipid peroxide levels were significantly lower in the stomachs of mice pre-treated with radon or hot spring water. These results suggest that hot spring water drinking and radon inhalation inhibit ethanol-induced gastric mucosal injury.
Tanaka, Hiroshi; Sakoda, Akihiro; Ando, Masaki; Ishimori, Yuu
Hoken Butsuri, 51(2), p.107 - 114, 2016/06
Ambient dose rates are continuously monitored in Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency. The present study discussed the variations in ambient dose rates, observed from April 2014 to March 2015, due to snowfall as well as rainfall. It is much snowy as one of climatic features in this area. Rain or snow was sampled for a certain period in the day of interest (17 cases in total), and then the concentration of radon progeny was measured. With the measured data, the variation in ambient dose rate was calculated considering the accumulation of the radon progeny on the ground. As a whole, this calculation was found to reasonably reproduce the time trends of observed dose rates, except for four cases. Based on the backward trajectory analysis, it was explained that the discrepancy in two cases out of the four was induced by changes of radon progeny concentration in precipitation around sampling period. It was suggested that the other two cases were caused by the run-off of rain from the ground surface.
Rn concentration model using a hydrodynamic meteorological model,1; One dimensional practical modelChino, Masamichi; Yamazawa, Hiromi; Iida, Takao*
Health Physics, 70(1), p.47 - 54, 1996/01
Times Cited Count：3 Percentile：32.72(Environmental Sciences)no abstracts in English
Ishikawa, Hirohiko; Yamazawa, Hiromi; Chino, Masamichi; *; *; *
Proc. of the Int. Conf. on Radiation Effects and Protection, p.385 - 389, 1992/00
no abstracts in English
; ; ; ;
JAERI-M 86-020, 88 Pages, 1986/02
no abstracts in English
Sekiya, Hiroyuki*; Iwata, Yoshihiro; Ito, Chikara
no journal, ,
no abstracts in English
Ishimori, Yuu; Tanaka, Hiroshi; Sakoda, Akihiro
no journal, ,
This paper illustrates environmental monitoring results in and around an old uranium mine site remediated by the Japan Atomic Energy Agency (JAEA). The site remediated is the waste rock site located on the steep slope of a hill about 1.5 km upstream from a residential area along a main ravine. Major remedial action was performed by covering the waste rock yards with weathering granite soil. Radon exhalation rate, radon concentration and 
-ray dose rate are mainly discussed. These measurements were carried out at about 30, 50 and 3300 points, respectively. These results prove that soil cover keeps its function over 5 years. In addition, environmental impact from the site has been negligible before the action.
Hirouchi, Jun; Nishizawa, Yukiyasu*; Urabe, Yoshimi*; Shimada, Kazumasa; Sanada, Yukihisa; Munakata, Masahiro
no journal, ,
After the Fukushima Dai-ichi Nuclear Power Station (NPS) accident, a series of aerial radiation monitoring (ARM) was conducted as a national project to map the ground surface distribution of radiocesium. The influence of -rays from natural nuclides, especially the radon progenies (Pb-214 and Bi-214) should be excluded from the ARM measurement data to accurately estimate deposition of artificial radionuclides. Therefore, the aim of this study is to develop a method for discriminating the influence of the radon progenies in air from the measurement data. The discrimination method was applied to the ARM data around Sendai NPS and we compared the dose rate at a height of 1 m above the ground measured by NaI survey meter with the ARM data. The coefficient of determination (R2) and normalized mean square error (NMSE) were improved by applying the method, showing that the validity of the method was confirmed.
Kataoka, Takahiro*; Kanzaki, Norie; Sakoda, Akihiro; Ishida, Tsuyoshi; Shuto, Hina*; Yano, Junki*; Tanaka, Hiroshi; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; et al.
no journal, ,
We have reported that radon inhalation activates antioxidative functions in mouse organs. These activation inhibits reactive oxygen species (ROS) induced oxidative stresses. Activation of antioxidative functions induced by radon inhalation probably due to the production of a small quantity of ROS. However, there were no reports on this mechanism. In this study, we evaluated hydrogen peroxide induced oxidative stress by radon inhalation in mouse organs. That is, mice inhaled radon at a concentration of 1 kBq/m or 10 kBq/m for 24 hours. Results showed that radon inhalation increased hydrogen peroxide in liver and lung by 20%. On the other hand, hydrogen peroxide in heart decreased by 20%. This is probably due to total glutathione reacts with hydrogen peroxide. These findings suggest that radon inhalation produces a small quantity of hydrogen peroxide, which is ROS, in mouse organs. However, antioxidative related substances, which are catalase and total glutathione, play an important role to reduce oxidative stress.
Kataoka, Takahiro*; Kanzaki, Norie; Sakoda, Akihiro; Ishida, Tsuyoshi; Tanaka, Hiroshi; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*
no journal, ,
We have reported that radon inhalation inhibits oxidative induced damages in some mouse organs due to activation of antioxidant functions. These activations are probably induced by reactive oxygen species following radon inhalation. In this study, we assayed the production of hydrogen peroxide and antioxidant associated substances in brain, lung, heart, liver, stomach, pancreas, kidney, small intestine, and colon in mouse after radon inhalation (1,000 or 10,000 Bq/m for 24 hours). Results showed that radon inhalation significantly decreased LPO levels in liver (1,000 Bq/m and 10,000 Bq/m) and heart (1,000 Bq/m), suggesting that radon inhalation inhibits oxidative stress. However, On the other hand, radon inhalation at a concentration of 10,000 Bq/m significantly increased the levels of LPO and hydrogen peroxide in lungs only. These findings suggested that radon inhalation at high concentration does not induce oxidative stress in other organs except lung.
