著者

永岡 美佳 藤田 博喜 中野 政尚 渡辺 均 住谷 秀一

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.48, no.2, pp.104-113, 2013 (Released:2014-03-06)

参考文献数

25

被引用文献数

1 4

---

Monthly deposition samples were collected at the Nuclear Fuel Cycle Engineering Laboratories located about 115 km south of the Fukushima Daiichi Nuclear Power Plant (NPP), and the radioactive nuclides were analyzed. Although radionuclides such as 131I, 129mTe-129Te and 132Te-132I with 134Cs and 137Cs were observed by gamma spectrometry at the early time of the Fukushima Daiichi NPP accident, only 134Cs and 137Cs were detected as of September 2011. The annual depositions of 134Cs and 137Cs were about 19,000 and 17,000 Bq m-2, respectively in March 2011-February 2012 after the accident. Moreover, 90Sr was detected in some samples. Monthly 90Sr deposition in March 2011 was 5.1 Bq m-2 month-1 and then decreased after that. On the other hand, 239, 240Pu concentration was the same level with the concentration before the accident.

著者

安東 量子

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.47, no.2, pp.102-107, 2012 (Released:2012-12-07)

参考文献数

1

被引用文献数

1 2

著者

浜田 信行 ロイ E. ショア ローレンス T. ダウアー

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.53, no.2, pp.47-64, 2018 (Released:2018-09-13)

参考文献数

60

被引用文献数

2 4

---

For over four decades, a linear nonthreshold (LNT) model has been used for radiation protection purposes. In the United States of America, the National Council on Radiation Protection and Measurements (NCRP) established Scientific Committee 1-25 in 2015 to prepare a commentary to review recent epidemiologic data from studies with low doses or low dose rates and from the Life Span Study of atomic-bomb survivors to determine whether these epidemiologic studies broadly support the LNT model. In May 2018, NCRP published Commentary No. 27 “Implications of recent epidemiologic studies for the linear nonthreshold model and radiation protection”, noting that the ongoing development of science requires a constant reassessment of prior and emerging evidence to assure that the approach to radiation protection is optimal, even if not necessarily perfect. Based on the current epidemiological data, NCRP concluded that the LNT model (perhaps with excess risk estimates reduced by a dose and dose rate effectiveness factor) should continue to be utilized for radiation protection purposes. The Commentary will be used to support the work of NCRP Council Committee 1 who are charged to develop current radiation protection guidance for the United States, ultimately updating and expanding the basic radiation protection recommendations of NCRP Report No. 116 published in 1993. This review provides an outline and summary of the key points of NCRP Commentary No. 27.

著者

藤原 慶子 高橋 知之 高橋 千太郎

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.51, no.1, pp.19-26, 2016 (Released:2016-07-06)

参考文献数

11

被引用文献数

4

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The accident at the Fukushima nuclear power plant in 2011 caused the release of large amounts of tellurium (Te) isotopes, with radio-cesium (Cs) and radio-iodine (I), into the environment. The total amounts of 127mTe and 129mTe released from the nuclear power plant were estimated as 1.1 × 1015 and 3.3 × 1015 Bq, respectively. At the location where the deposition of 129mTe was relatively large, the ratio of the radioactivity of 129mTe to that of 137Cs reportedly reached 1.49 on June 14, 2011. Since 127mTe has a relatively long half-life, it possibly contributed to the internal radiation dose at the early stage after the accident. In this paper, the ratio of the committed effective dose of 127mTe to that of 137Cs after the oral ingestion of rice was estimated by using various reported parameters. The relevant parameters are: 1) the deposition ratios of 127mTe, 129mTe, and 134Cs to 137Cs; 2) the deposition ratio of 127mTe to 129mTe; 3) the transfer factors of Te and Cs; and 4) the effective dose coefficients for 127mTe, 129mTe, 134Cs, and 137Cs. The ratios of the committed effective dose of 127mTe to that of 137Cs were calculated for adults after a single ingestion at the time of the rice harvest. The ratio was 0.45 where the 129mTe/137Cs in the soil was higher and 0.05 where the level of 129mTe/137Cs was average. The ratio of the committed effective dose from 129mTe and 127mTe to that from 137Cs for one year reached 0.55 and 9.03 at the location where the level of 129mTe/137Cs in the soil was higher. These data could indicate that radioactive Te should not be disregarded in reconstructing the internal radiation dose from food for one year after the accident.

著者

飽本 一裕

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.49, no.1, pp.17-28, 2014 (Released:2015-02-26)

参考文献数

49

被引用文献数

1 4

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In this report, several works on mainly resuspension and eolian transfer of radioactive cesium due to wind, which is one of the most effective transfer processes of previously deposited radioactive particulate materials, are introduced. First, the mechanisms of the resuspension of particulate matter by wind as well as resultant dust storms and wind erosion are surveyed. Next, the papers related to resuspension and eolian transfer of radioactive aerosols originally emitted by the Chernobyl nuclear accident are reviewed. The measured fallouts and radioactivity concentrations show annual cycles, and their peak periods depend on the measured regions. Finally, the works that analyze the related effects of the accident at the Fukushima Daiich Nuclear Power Plant are reviewed, and some issues to be focused and resolved are summarized.

著者

半澤 隆宏

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.48, no.2, pp.67-72, 2013 (Released:2014-03-06)

被引用文献数

1 3

著者

中野 政尚 國分 祐司 武石 稔

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.44, no.1, pp.60-65, 2009 (Released:2010-10-08)

参考文献数

15

被引用文献数

4

---

The tritium concentrations in seawater collected around the Tokai Reprpcessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of expected diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.

著者

田中 俊一

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.53, no.3, pp.133-134, 2018 (Released:2018-11-27)

被引用文献数

1

著者

中野 政尚 國分 祐司 武石 稔

出版者

日本保健物理学会

雑誌

保健物理 : hoken buturi (ISSN:03676110)

巻号頁・発行日

vol.44, no.1, pp.60-65, 2009-03

被引用文献数

4

---

The tritium concentrations in seawater collected around the Tokai Reprpcessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of expected diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.

著者

河野 恭彦 檜山 佳典 中野 政尚 武石 稔

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.44, no.2, pp.209-217, 2009 (Released:2010-11-02)

参考文献数

15

---

We surveyed the concentration levels of Transuranium (TRU) nuclides in the effluent discharged from the Tokai Reprocessing Plant (TRP) from 1998 to 2003 for Light Water Reactor (LWR) Fuel Reprocessing. The survey was performed for upcoming the effluent monitoring in Fast Breeder Reactor (FBR) Fuel Reprocessing. It was confirmed that the TRU nuclides concentration discharged from the TRP was 1/150∼1/106 much lower than the concentration limits authorized in governmental notification. Then, we compared the normalized discharge amounts by the unit of generated energy from the TRP with those from the foreign reprocessing plants. As a result, the TRP has reduced the amounts of discharged nuclides, by the order of 1/100-1/107 compared with foreign ones. This survey provided the important and basic data in order to compare the effluent of TRU nuclides in FBR and the present nuclear fuel cycles.

著者

工藤 伸一 石田 淳一 吉本 恵子 水野 正一 大島 澄男 古田 裕繁 笠置 文善

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.51, no.1, pp.12-18, 2016 (Released:2016-07-06)

参考文献数

16

被引用文献数

7

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Radiation Effects Association has carried out radiation epidemiological study for nuclear industry workers during 1990-2010. We assembled a cohort of 204,103 workers. The average cumulative dose was 13.8 mSv (median 1.0 mSv, interquartile range (IQR) 0.0-10.7 mSv) and the average follow-up period was 14.2 year. The present report has not concluded that low-dose radiation increases cancer mortality based on the follow-up data through 2010. One reason is that analyses among 75,442 respondents― the average cumulative dose was 25.8 mSv (median 6.3 mSv, IQR 0.2-28.0 mSv) and the average follow-up period was 8.3 year―to the lifestyle surveys revealed the decrease of the ERR after adjusting for smoking habits or educational year, suggesting that confounder has a large effect on the association between radiation exposure and mortalities in the cohort. Another reason is that in analyses on all cohort members, no significant ERR was observed in all death, and leukemia excluding chronic lymphoid leukemia. Significant ERR was seen in all cancers excluding leukemia, but this significance of the ERR might be affected by confounder such as smoking, because the significance of the ERR in all cancers excluding leukemia originates in the significance of the ERR in lung cancer.

著者

加藤 秀起 古賀 佑彦 向山 隆史 戸松 弘孝 鈴木 友輔 鈴木 昇一

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.44, no.4, pp.380-386, 2009 (Released:2011-01-12)

参考文献数

7

被引用文献数

3

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In one of the accidents that might happen in the nuclear power station, there is a contamination accident caused by radioactive corrosion products during a periodic inspection. It is necessary to presume the skin absorbed dose from the adhesion area and the contamination density to forecast the level of the skin hazard by the adhesion of the radioactive substance. However, the data to forecast the local skin dose when the radioactive substance adhered handily is not maintained. In this paper, the absorbed dose in the skin surface neighborhood contaminated by radioactive corrosion products was calculated, and the relation between the adhesion area and the contamination density and the local absorption dose was derived. And, the approximate equation that forecast the integrated dose was derived from these data. As for the absorbed dose rate in depth 70 μm from the skin surface that became the index of the skin hazard, the contribution rate by 59Fe was the highest within 30 days, and the contribution of 60Co rose most after the 30th after the radioactive substance had adhered when the contamination density the adhesion area was the same. The relation between the initial contamination density and days that required it was graphed to reaching to the threshold by the integrated dose when the threshold dose in which the necrosis of the skin was caused was assumed to be 20 Gy. The absorbed dose commitment can be presumed from measurements of the contamination density by using this graph or the approximate equation.

著者

宮崎 真 大津留 晶

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.47, no.2, pp.108-112, 2012 (Released:2012-12-07)

被引用文献数

1

著者

荻野 晴之 大葉 隆

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.48, no.3, pp.134-138, 2013 (Released:2013-12-10)

参考文献数

2

著者

横山 直方

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.30, no.3, pp.243-250, 1995 (Released:2010-02-25)

参考文献数

18

著者

福島 靖正

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.47, no.1, pp.17-19, 2012 (Released:2012-09-06)

被引用文献数

3 6

著者

松永 武 小林 健介

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.36, no.1, pp.31-44, 2001 (Released:2010-02-25)

参考文献数

56

被引用文献数

4

---

The prophylactic use of stable iodine is one of the protective measures during a nuclear emergency. In order to know the resultant radiation dose to the thyroid gland and the effectiveness of iodine prophylaxis in the case of Japanese, a sensitivity analysis was performed for related physiological parameters for Japanese. As a result, the variances in the deposition efficiency of radioactive iodine aerosol in the respiratory tract due to changes in the respiratory parameters were found rather small between the standard Caucasian and Japanese. The changes due to the radioactive iodine aerosol size were more significant, suggesting the importance of understanding the physico-chemical status of aerobic radioiodine released in a nuclear emergency. Concerning the metabolic parameters of iodine, the result of the sensitivity analysis based on an iodine metabolic model showed that the most critical parameters are those which describe the transport of stable and radioactive iodine from the blood compartment to the thyroid gland. Accordingly, a confirmation of the transport model and the related parameters for Japanese are essential to clarify the effectiveness of iodine prophylaxis to reduce thyroid gland exposure of Japanese. (This work was performed under the auspices of the Science and Technology Agency of Japan.)

著者

須賀 新一 市川 龍資

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.35, no.4, pp.449-466, 2000 (Released:2010-02-25)

参考文献数

31

被引用文献数

8 8

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This paper describes the revised index levels of the control of food and water in the Nuclear Safety Commission guidelines, “Off-Site Emergency Planning and Preparedness for Nuclear Power Plants, etc.” Food and water are divided into five categories, and the consumption of each has been conjectured. For this purpose, a nationwide survey for nutrition in Japan by the Welfare Ministry and a survey on the food of infants and children in the coastal area of Ibaraki Prefecture by the National Institute of Radiological Sciences are considered. These categories are (1) drinking water, (2) milk and dairy products, (3) vegetables, (4) grain, and (5) meats, egg, fish, shellfish, and others. The radionuclides groups are then chosen in consideration of their potential importance in regard to food and water contamination. Those chosen were, (1) radio-iodine, (2) radioactive cesium and strontium, (3) uranium, and (4) plutonium and alpha-rayemitting transuranic radionuclides. The intervention dose levels of 5mSv of effective dose and 50mSv of committed equivalent dose to the thyroid for radio-iodine for a period of one year were adopted. The radioactivities of 131I, 132I, 133I, 134I, 135I, and 132Te are assumed to be proportional to the contents in nuclear fuel after a cooling time of 0.5 day, and the radioactivity of 131I is taken as a scale that represents the level of control on the ingestion of food and water. Based on doses to infants, whose exposure is highest, the levels of control are recommended to be 300Bq/kg or more for drinking water and milk and other dairy products, and 2, 000Bq/kg or more for vegetables, except edible roots and potatoes. It is assumed that radio-cesium released in the environment is accompanied by strontium radio-nuclides with a 90Sr/137Cs radioactivity ratio of 0.1, taking into account the past measurements of fallout. Radio-nuclides are assumed to contain 137Cs, 134Cs, 90Sr, and 89Sr with the same mixing ratio as that of the fuel in a nuclear reactor. The sum of radioactivity of 134Cs and 137Cs is used as a scale that represents the level of control, and the yearly average concentration in food and water is presumed equal to half the concentration of those in the peak term. It has then been recommended that the levels of control for radio-cesium should be 200Bq/kg or more for drinking water and milk and other dairy products, and 500Bq/kg or more for vegetables, grain, meat, eggs, and fish. Moreover, in special cases, measurements on radio-strontium are necessary if a nuclear power reactor operates for less than two years because the ratio of 89Sr radioactivity is much higher than in reactors with longer times of operation. For uranium, the index levels are presented in terms of alpha-activity concentration: 20Bq/kg or more for drinking water and milk and other dairy products, and 100Bq/kg or more for vegetables, grain, meat, eggs, and fish. The sum of the radioactivity concentration of 238Pu, 239Pu, 240Pu, 242pu, 241Am, 242Cm, 243Cm, and 244Cm is selected as a scale for representing the levels of control on food and water for plutonium and other transuranic radionuclides. The level of control has been recommended as 1Bq/kg or more for drinking water and milk and other dairy products, and 10Bq/kg or more for vegetables, grain, meat, eggs, and fish. For commercially available food for babies, the recommended level of control is 1Bq/kg or more in a cooked form and served as a meal for plutonium and other transuranic radionuclides.

著者

渡邉 正己

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.47, no.2, pp.118-123, 2012 (Released:2012-12-07)

参考文献数

15

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It has been believed that the first target of radiation carcinogenesis is DNA. However, this is not proved for radiation carcinogenesis yet. We discovered that frequency of aneuploid cell was closely related to that of radiation-induced cell transformation and natural cell transformation by high-density cultivation, but gene mutation was not. Cell with p53 gene becomes tetraploid, but does not get tumorigenicity. On the other hand, cells without p53 gene function become a triploid easily, and acquire tumorigenicity. Both radiation exposure and high-density cultivation elevated the level of intracellular oxidative radicals. These radicals induced centrosome destabilization and produced cells carrying extra centrosome, which promote merotelic attachment of chromosome by altering spindle geometry. Unresolved merotelic attachments can give rise to lagging chromosomes at anaphase. Aneuploidy was seen in high frequency in early process of cell transformation. These results strongly suggest that a main target of carcinogenesis by low dose radiation is not DNA, but is centrosome, which are the proteins to constitute chromosomal homeostasis maintenance mechanism. In addition, this route may be the same as that of natural carcinogenesis. These serial results support necessity of a review of a LNT hypothesis at a radioprotective point of view.

著者

中村 典

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.35, no.2, pp.217-223, 2000 (Released:2010-02-25)

参考文献数

14

被引用文献数

1