著者

片岡 憲昭 中嶌 純也 大津 彩織 高橋 映奈 髙宮 圭 梅田 昌幸 西小野 華乃子

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.56, no.1, pp.28-31, 2021-03-31 (Released:2021-05-26)

著者

小西 恵美子 小野 道実 小泉 彰 河内 典子 吉沢 康雄

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.4, no.4, pp.594-602, 1969 (Released:2010-03-15)

参考文献数

5

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In spite of the increasing use of electron microscopes, very few considerations have been given to the emission of radiation from the equipment. This is mainly due to the fact that the radiation is emmitted as “an unwanted by-product”of the equipment. Radiation surveys were carried out on twelve epuipments of Japanese manufacture. Informations obtained from the surveys were;1) Radiation leakage was observed from eight equipments.2) Electron gun, viewing window and photo-chamber were main locations where radiation leakage was observed.3) Structural defects in the equipment were important causes of radiation leakage.Following opinions were offered from a health physics standpoint;1) The equipment is required to be constructed and installed so as to provide adequate protection.2) A legalistic radiation safety standard is neededfor theequipment manufacturer.3) In a radiation safety program, it is important to obviate any radiation leakage rather than to assess the doses liable to be incurred.

著者

松野 太郎

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.21, no.3, pp.199-207, 1986 (Released:2010-02-25)

参考文献数

6

著者

小川 真澄 熊谷 敦史 青野 茂昭 葛巻 和枝 立崎 英夫 山下 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.56, no.3, pp.145-152, 2021-10-12 (Released:2022-01-06)

参考文献数

18

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Since the end of 2019, we have faced a COVID-19 (coronavirus disease 2019) pandemic with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Medical institutions must treat COVID-19 patients while preventing health care workers and other patients from nosocomial infections. COVID-19 also needs to be considered in a case of radiation emergency medicine. Although radioactive materials (RI) and SARS-CoV-2 are different, they have much in common in health risk management when we receive such patients in that they are undetectable by all our five senses and require personal protective equipment (PPE). On the other hand, there are some notable points on preparedness and response for their risk management. We cannot detect SARS-CoV-2 in real-time but can sterilize them with alcohol-based hand sanitizer. RI is difficult to be decontaminated entirely but detectable in real-time with a suitable radiation survey instrument. Under the COVID-19 situation, it is a great challenge to deal simultaneously with a radiation protection and an infection control, especially in an emergency situation of radiation exposure. In order to overcome such difficulty, we at first compare the similarity and difference of risk management between RI exposure and SARS-CoV-2 infection. Then the points of attention are introduced how to manage the radio-contaminated patients with a coexistence of SARS-CoV-2, including the fundamental concept of zoning, PPE, and hand-over of equipment.

著者

杉浦 紳之 平 純一 竹中 圭介 山中 和夫 菅井 研自 小佐古 敏荘

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.42, no.3, pp.214-220, 2007 (Released:2010-08-05)

参考文献数

13

被引用文献数

7 7

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The smear test is one of the important ways to measure surface contamination. The loose contamination under the high back-ground radiation, which is more significant in handling non-sealed radioisotopes, can be evaluated by this method. The removal factor is defined as the ratio of the activity removed from the surface by one smear sample to the whole activity of the removable surface contamination. The removal factor is greatly changed by the quality and condition of surface materials. In this study, the values of removal factor at several typical surface conditions were evaluated experimentally and the practical application of those values was considered. It is required the smear should be pressed by moderate pressure when wiping the surface. The pressure from 1.0kg to 1.5kg per filter paper was recommended. The removal factor showed lower value in wiping by the pressure below 1.0kg. The value of 0.5 for the removal factor could be applied to the smooth surface of linoleum, concrete coated with paint or epoxy resin, stainless steel and glass with the statistical allowance.

著者

永田 暢秋 和田 弘 門井 英一 谷口 和史 渡辺 義史 生駒 英也 仙波 毅 浜口 俊明

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.45, no.1, pp.57-64, 2010 (Released:2011-02-04)

参考文献数

7

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The zinc injection technique has been applied to many PWRs (Pressurized Water Reactors) around the world as one of the most effective countermeasures against a radiation source reduction. More than 10 years have passed since the first application of the zinc injection technique mainly in Europe and the US, and its dose reduction effect has been confirmed in each nuclear power plant. The Japan Atomic Power Company has applied the zinc injection technique to Tsuruga nuclear power plant unit 2 (PWR, 1,160 MWe, Commercial operation started in 1987) since 2005. Zinc concentration in primary coolant had been controlled around 5ppb by not more than 10 ppb. Dose equivalent rates on primary equipment and pipes were reduced about 20-30% after zinc injection. Although the dose reduction effect of 20-30% is included the various factors, it was estimated that the effect of about 10% is due to the zinc injection technique. There were no negative effects caused by the zinc injection for the plant operation, water chemistry and fuel integrity in the case of Tsuruga unit 2.

著者

寿藤 紀道 小林 育夫 村上 博幸 三宅 敏雄

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.36, no.1, pp.95-101, 2001 (Released:2010-02-25)

参考文献数

1

被引用文献数

1

著者

山口 彦之 吉田 芳和 田野 茂光 備後 一義 片桐 浩

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.20, no.4, pp.349-356, 1985

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<i>Tradescantia</i> (clone KU-7) were grown at three points near a site of nuclear power plants and somatic mutation frequencies in <i>Tradescantia</i> stamen hairs were investigated for three years. The two points are located in the prevailing down-wind sector of the site. Mutational events in stamen hair cells were scored every day from the end of April to October for three years. In parallel with this observation, factors which have been thought to affect mutation induction, such as temperature, humidity, insolation, pollutants, radioactivity in the buds were measured at the three points. The daily exposure and radioactive concentration at three points due to the amount of the radioactive nuclide released from the nuclear power plant were calculated.<br>Mutation frequencies fluctuated daily, but they were estimated rather constant on average at three sites. Increase of radioactivities in the buds or other plant tissues was not detected during this experiment. The daily exposure and radioactive concentration were very low, for example, the ratio of the maximum daily exposure to the doubling dose was less than 1&times;10^-7.<br>It has been definitely shown by this field experiment that radionuclide released from the nuclear power plants can not induce significant mutation of <i>Tradescantia</i>.<br>It was concluded that <i>Tradescantia</i> stamen hair system was not appropriate to monitor the environmental radiation from the power reactor.

著者

山下 淳

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.11, no.4, pp.263-274, 1976

被引用文献数

2

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<i>Tradescantia</i> in studies on genetic effects of low level radiation is briefly introduced. Radiosensitivity, method of screening stamen hair mutation, materials in current uses, spontaneous mutation rate, and modifying factors are refered. For stamen hair mutation b values in exponential model were lower in irradiation with low dose rate and at high environmental temperature. The dose response curves under these modifying conditions, when extrapolated to low dose range, well fit to the line which was obtained by Sparrow's experiment of low level irradiation. In chronic irradiation, the frequency of stamen hair mutation reaches to the constant value after 17 days from the start of irradiation, and is as much as 4 times higher than the peak value in one day irradiation at the same exposure rate. The spontaneous mutation rate of KU-7 varied with temperature. The increase with 1&deg;C increment of mean temperature was -0.04%. Uses of <i>Tradescantia</i> in monitoring the environmental radiation is discussed.

著者

岩井 敏

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.43, no.3, pp.211-225, 2008 (Released:2010-08-05)

参考文献数

40

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In the field of radiation protection, quality factor Q (L) and radiation weighting factor wR are important coefficients for estimating both radiation protection and operational quantities to the mixed types of radiation exposure. However, some inconsistencies might be found between Q (L) and wR for estimating effective dose, for example. Some inconsistencies are attributed to incomplete definition of terms Q (L) and wR. This report presents the root and evolution of quality factor Q (L) and radiation weighting factor wR for the years 1931-2007, to clarify the current issues of inconsistencies to be solved.

著者

小木曽 洋一 山田 裕司 飯田 治三 福津 久美子 福田 俊

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.33, no.3, pp.308-313, 1998 (Released:2010-02-25)

参考文献数

15

著者

泉 幸男 藤田 稔 矢部 明

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.7, no.4, pp.213-219, 1972 (Released:2010-02-25)

参考文献数

9

被引用文献数

1 1

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The contents of 131I in the thyroid of radioisotope workers were measured with a large NaI (T1) detector. For this purpose, a practical and convenient method was developed to estimate the fraction of 131I in the thyroid of that in the total body, f2, as well as the contents of 131I in the thyroid.The observed value of 131I content in the thyroid varied to some extent with the difference of the relative position between the thyroid and the detector. Three per cent of the coefficient of variation. was observed at actual measurements for human subjects.The values of f2 for 63 people who inhaled 131I were determined. They fit a log-normal distribution on ranging widely from 0.17 to 0.68. The geometrical mean was calculated as 0.28. In addition, the change with time of the 131I contents in the thyroid was followed for 11 cases to determine the effective half-lives. These values ranged from 4.9 to 7.6 days and the mean value with the standard deviation was 6.6±0.7 days. This mean value is a little less than the value for the standard man (7.6 days) given by the ICRP.

著者

廣内 淳 谷 幸太郎 玉熊 佑紀 仲宗根 峻也 小池 弘美

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.55, no.4, pp.185-190, 2020

著者

浅野 孝 小林 保 樋熊 孝信

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.8, no.1, pp.33-37, 1973

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Half-face masks have been used routinely at plutonium facilities in the Power Reactor and Nuclear Fuel Development Corporation. In 1970, a mask man-test began to evaluate the protection efficiencies of masks when wearing and to instruct workers how to wear them properly. DOP was used as a test aerosol, and 232 persons were tested. In the first test 70% of the persons could wear the masks with a good fit (leak rate less than 1%). The persons with leak rate over 1% were repeatedly tested to investigate causes of the leak.<br>The persons were classified into three groups; the first one having experience of wearing masks, the second one having no experience and the third one being given some instructions about masks before the test. The persons in the first group weared the masks better than those in the second group, but the test suggest the instruction is the most effective.<br>The methods procedures and results of the tests are described.

著者

浜田 信行

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.52, no.3, pp.159-166, 2017 (Released:2017-11-15)

参考文献数

27

被引用文献数

1 1

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In its latest basic recommendations issued in 2007, the International Commission on Radiological Protection (ICRP) recommends that the working conditions of a pregnant worker, after declaration of pregnancy, be such as to ensure that the additional dose to the embryo and fetus would not exceed about 1 mSv during the remainder of the pregnancy, where exposures of the embryo and fetus of pregnant workers are considered and regulated as public exposures. However, it remains unclear, e.g., [1] whether such recommended additional dose of about 1 mSv to the embryo and fetus is the whole body equivalent dose or the effective dose, [2] if the latter, how to compute the effective dose while the currently recommended tissue weighting factors (wT) do not include the stochastic risks of in utero exposures and while the unavailability of the current epidemiological data sets does not allow computation of detriment for in utero exposures, and [3] whether the embryo and fetus are the public. This paper briefly reviews historical changes in ICRP recommendations on protection of pregnant workers, embryo and fetus, and then discusses pertinent issues behind the 2007 recommendations.

著者

永井 晴康

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.13-16, 2012 (Released:2012-09-06)

参考文献数

13

被引用文献数

1 2

著者

山本 政儀

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.24, no.3, pp.249-257, 1989 (Released:2010-02-25)

参考文献数

11

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The accident at the Chernobyl reactor site starting at 26th April 1986 caused a widespread distribution of radionuclides. In all countries radiation measurements and analyses of samples have been made to show the features to consider in a dosimetric evalution, but transuranium elements have been less investigated.In Europe, the determination of several transuranium elements, such as neptunium (Np-239), plutonium (Pu-238, 239, 240, 241), americium (Am-241) and curium (Cm-242) was possible. The total depositions (mBq/m2) at Monaca, Rise (Denmark) and Neuherberg (Munich) were estimated to be 10, 20 and 51, respectively. These levels are only 0.01-0.05% of the previous deposition from nuclear weapons tests. The activity ratios Pu-238/Pu-239, 240 (0.4-0.5) and Pu-241/Pu-239, 240 (80-90) from Chernobyl fallout were much higher than those from nuclear weapons tests. Here, a more detailed feature of transuranium elements released into environment from the Chernobyl reactor is presented comparing with that from nuclear weapons fallout, including the measurements of transuranium elements of the Chernobyl debris in Japan.

著者

角川 正義 井上 義教

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.2, no.2, pp.81-94, 1967-06-30 (Released:2010-02-25)

参考文献数

76

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The causes of fires of plutonium and uranium in the nuclear facilities are summalized through the literature survey of accidents in the United States and the United Kingdom, and of metallurgical studies. It is noticeable that spontaneous ignition is due to the operations such as of degreasing, leaching, cutting and scraping, to the treatment with nitric acid, or to the existence of moisture, for example, after low-temperature experiment of the metals.The methods of fire-prevention and fire-fighting at the plutonium fires are also described with the recommendation on the view point of health physics: Aluminum icontaner is likely to have excellent property for the fire prevention. The data of particle size distribution and deposition velocity of plutonium emitted at the fire are also showed. Finally, the efficient agent and technique of fire extinguishing are described with some data from experiences in the accidents and the laboratory experiments.

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

被引用文献数

1

著者

甲斐 倫明

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.45, no.4, pp.311-312, 2010