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Asakawa, Jun; Kimura, Yasuhisa; Hirano, Hiroshi*; Kitamura, Akihiro
Hoken Butsuri (Internet), 60(1), p.63 - 73, 2025/04
Be deposition in Hokuriku, JapanYoshida, Keisuke; Kato, Shingo; Okuyama, Shinichi; Nakano, Masanao; Ishimori, Yuu; Uchida, Kengo*; Inoue, Mutsuo*
Hoken Butsuri (Internet), 60(1), p.40 - 47, 2025/04
Monthly
Be depositions were examined at four sites in Hokuriku, Japan, from 1992 to 2021. The amounts of
Be depositions in Hokuriku from October to March differed locally: Depositions at Kanazawa were high (4400 Bq/m
), a site along the foot of the mountains.
Be depositions in the plain of Fukui city, along Wakasa Bay, and along the coast of the Noto Peninsula (3300, 2800, and 2500 Bq/m
, respectively) were equivalent to those of other areas along the coast of the Sea of Japan. The local variation in
Be depositions in Hokuriku is predominantly ascribed to precipitation, topographic feature, and
Be concentrations.
Nagai, Yuya; Kimura, Yasuhisa; Hirano, Hiroshi*; Kitamura, Akihiro
Hoken Butsuri (Internet), 59(4), p.168 - 181, 2024/12
We have dismantled one glovebox that stood very near at the wall of a controlled room and a part of one transfer tunnel that penetrated walls of control rooms. We have developed new containment boundaries because conventional tent enclosure cannot be applied to these objects. In this report, we present the features of new containment boundaries and dismantlement procedures we have developed and the details of the dismantlement activities we have implemented.
Hosoda, Masahiro*; Omori, Yasutaka*; Orita, Makiko*; Saito, Kimiaki; Sanada, Tetsuya*; Takeda, Hikaru*; Tani, Kotaro*; Tsujiguchi, Takakiyo*; Hirao, Shigekazu*; Hokama, Tomonori; et al.
Hoken Butsuri (Internet), 59(4), p.206 - 207, 2024/12
no abstracts in English
Omaru, Aiko*; Shimizu, Hideo*; Manabe, Kentaro; Miyajima, Yasutaka*; Enomoto, Atsushi*
Hoken Butsuri (Internet), 59(4), p.196 - 201, 2024/12
On June 27 and 28, 2024, the symposium of the Health Physics Society of Japan was held online. The symposium included lectures on the purpose and activity policies of the two special study groups established in FY2024, a report from a special study group on the consideration of radioactive waste from a humanities and social science perspective whose activities have been completed, a session on risk communication by a young study group, and sessions on the recent activities of the International Radiation Protection Committee's recent activities and a session on medical exposure. This report provides an overview of each session, including the impressions of the Health Physics Society of Japan planning committee members involved in the relevant fields.
Sakoda, Akihiro; Ishimori, Yuu
Hoken Butsuri (Internet), 59(3), p.109 - 117, 2024/09
International organizations such as WHO and ICRP recommended reference levels with the range of 100
300 Bq/m
against residential radon exposure. In Japan, indoor radon activity concentration is generally low, and a national plan and reference level have not been set so far. This study aimed to evaluate the risks of indoor radon among Japanese populations and to discuss the effectiveness of an assumed reference level in terms of reduction in the number of lung cancer deaths. The US EPA model was used to calculate lifetime risks and population attributable fractions for ever smokers and never smokers using the recent Japanese-specific information such as demographic data and smoking prevalence. The result indicated that the number of lung cancer deaths was very low (i.e., less than 10 in 2020) among the population exposed to more than 100 Bq/m
. This means that even if a reference level of 100 Bq/m
is set, the statistically significant reduction in lung cancer deaths could not be observed. Given the risk evaluation, we believe that expected national actions in Japan are to support individuals who consider taking measures for the own risk perception and control of lifetime risk, rather than to introduce regulations. Comprehensive argument and judgement would also be desired for better public health, based on information on not only radon but also other common modifiable risk factors.
Saito, Kimiaki
Hoken Butsuri (Internet), 59(2), p.43 - 44, 2024/06
no abstracts in English
Yasuda, Hiroshi*; Saito, Tatsuo; Fumoto, Hiromichi*; Sugawara, Shinetsu*; Tsuchida, Shoji*; Kasai, Atsushi*; Furuta, Sadaaki*
Hoken Butsuri (Internet), 58(3), p.120 - 134, 2023/11
This paper is a summary of the activity report of the specialized study group of the Japan Health Physics Society on handling of naturally occurring radioactive wastes from humanities and social sciences perspective. To ensure the reliability of the long-term assessment, this special committee first reviews options for disposal of uranium waste depending on its concentration, especially those adopted or considered in Japan and overseas (U.S.A., U.K.) for uranium concentrations exceeding a sufficiently small amount of uranium (an average of 1 Bq/g of the sum of
U,
U, and
U).
-ray dust monitor for highly-concentrated airborne contaminantsSagawa, Naoki; Fujisawa, Makoto; Hosomi, Kenji; Morishita, Yuki; Takada, Chie
Hoken Butsuri (Internet), 58(3), p.135 - 140, 2023/11
Radioactivity concentrations of airborne dust are important measurements because they are used to protect workers from intakes and to assess internal exposure doses. Therefore, we developed a portable
-ray dust monitor by using an ultra-thin plastic scintillator, which is designed for continuous monitoring of highly-concentrated airborne contaminants (
10
Bq/cm
, equivalent to 30 times larger than the derived air concentration of
Sr) such as a decommissioning work in the Fukushima Daiichi Nuclear Power Plant. From the performance test results, it is evaluated that the developed portable
-ray dust monitor is functional in continuous monitoring with an airborne concentration of 1 Bq/cm
.
Yamada, Ryohei*; Tamakuma, Yuki*; Kuwata, Haruka*; Saigusa, Yumi*; Watanabe, Yuki; Hirota, Seiko*; Jin, Q.*; Cai, Y.*
Hoken Butsuri (Internet), 58(3), p.169 - 177, 2023/11
no abstracts in English
Takahara, Shogo; Iimoto, Takeshi*; Igarashi, Takayuki*; Kawabata, Masako*
Hoken Butsuri (Internet), 58(2), p.50 - 58, 2023/08
The Health Physics Society of Japan established a working group to obtain the insights and findings from the articles, which are related to the Fukushima Daiichi Nuclear Power Station (1F) accident, published in the Japanese Journal of Health Physics. This paper describes the results of the review on 47 articles, which are classified into the field without risk communication, environmental measurement and monitoring, radiation dose measurement and assessment, radiation medicine and radioactive waste. In the reviewed articles, there are various insights and issues depending on the standpoint of the authors and social interests in the timing those published. It is important to face these insights and issues to consider prudently "what is health physics or radiation protection?" for the future development of the Health Physics society.
Shibanuma, Tomohiro; Hirano, Hiroshi*; Kimura, Yasuhisa; Aita, Takahiro; Yoshida, Masato; Nagai, Yuya; Kitamura, Akihiro
Hoken Butsuri (Internet), 58(2), p.91 - 98, 2023/08
We developed new containment tents that are more easily assembled and effectively functioned, by improving and refurbishing the shortcomings of the conventional tents. The new tents have been already tested in the real airborne contamination situation occurred at the plutonium fuel fabricating facility. The tents appropriately functioned for intended use but other shortcomings emerged and therefore we had modified the structure of the tents further.
Kitamura, Akihiro; Hirano, Hiroshi*; Yoshida, Masato; Takeuchi, Kentaro
Hoken Butsuri (Internet), 58(2), p.76 - 90, 2023/08
The alpha contaminated gloveboxes have been dismantled for over 20 years in Plutonium Fuel Fabrication Facility. The so called wet recovery equipment gloveboxes, which recover plutonium and uranium from scrap fuel by dissolving and extracting processes, were chosen as the priority gloveboxes to be dismantled. These gloveboxes and other gloveboxes in the same room were size reduced and removed up until 2022. Also, non-radioactive ancillary facility and non-radioactive giant glovebox were removed from 2007 to 2010 for ease of glovebox dismantling activities that follows and for making waste storage spaces. Several incidents were occurred and recidivism prevention measures were implemented on each occasion. In this report, glovebox dismantling activities we conducted in the past 20 years are reviewed and lessons we have learned are summarized.
Yoshitomi, Hiroshi; Manabe, Kentaro; Ochi, Kotaro; Kono, Takahiko; Sasaki, Michiya*; Yoshida, Hiroko*
Hoken Butsuri (Internet), 58(2), p.105 - 111, 2023/08
This article gives the report on participation in the 6th Asian and Oceanic Congress on Radiation Protection (AOCRP6), which was held in Mumbai, India on between February 7th and 11th, 2023.
Nakajima, Junya; Hirota, Seiko*; Tsuji, Tomoya; Watanabe, Yuki; Sakoda, Akihiro; Kobayashi, Noriko*
Hoken Butsuri (Internet), 58(1), p.13 - 20, 2023/04
no abstracts in English
Yasuoka, Yumi*; Fujita, Hiroki; Tsuji, Tomoya; Tsujiguchi, Takakiyo*; Sasaki, Michiya*; Miyazaki, Tomoyuki*; Hashima, Shun*; Yasuda, Hiroshi*; Shimada, Kazumasa; Hirota, Seiko*
Hoken Butsuri (Internet), 57(3), p.146 - 155, 2022/12
no abstracts in English
Asakawa, Jun; Hirano, Hiroshi*; Nagai, Yuya; Aita, Takahiro; Shibanuma, Tomohiro; Kimura, Yasuhisa
Hoken Butsuri (Internet), 57(2), p.93 - 101, 2022/09
In the dismantling work of glove boxes (GBs) contaminated with radioactive materials at the nuclear fuel facilities, plastic tents are constructed around the entire GBs, and workers putting on air-fed suits (AFS) (hereinafter referred to as AFS worker) dismantle the GBs and interior equipment by using cutting tools. If an AFS worker suddenly feels sick during the work and the worker is unable to move independently, it will be necessary to exit in the shortest time from the viewpoint of respecting human life. In this case, a lot of radioactive materials may be brought into the contamination control room, thus the room and the equipment of the workers may be contaminated. Consequently, until the decontamination work is completed, the other AFS workers will have to put on AFS and wait for long time, which puts a strain on the workers. In this report, the plastic enclosure tents for body decontamination developed in JAEA were used as a new contamination control room replaced the contaminated one, and the procedure to quickly exit the remaining AFS workers was proposed. As a result, we confirmed that it was possible to greatly reduce the waiting time of the other AFS workers who is forced to wait in the dismantling area.
Sakoda, Akihiro; Tsuji, Tomoya; Hirota, Seiko*; Watanabe, Yuki
Hoken Butsuri (Internet), 57(2), p.108 - 114, 2022/06
no abstracts in English
Hokama, Tomonori; Otoshi, Kazuki*; Kataoka, Noriaki*
Hoken Butsuri (Internet), 57(1), p.65 - 69, 2022/03
no abstracts in English
Shimada, Taro; Nemoto, Hiromi*; Takeda, Seiji
Hoken Butsuri (Internet), 57(1), p.5 - 29, 2022/03
Of the asbestos-containing wastes arising from the dismantling activities of nuclear facilities, those with radioactive concentrations that do not need to be treated as radioactive substances will be cleared from the nuclear regulatory control. Those will be disposed of or recycled as specially controlled industrial waste based on the Waste Management and Public Cleansing Act. The authors constructed evaluation scenarios according to the treatment manual for asbestos-containing waste and evaluated public exposure doses per year for 33 radionuclides. Based on the evaluated doses, the radioactive concentration corresponding to the dose criteria of 10
Sv/y for clearance was calculated for each radionuclide and scenario. As a result, the evaluated concentration was equal to or higher than the current clearance level. It was confirmed that the application of the current clearance level for asbestos-containing wastes did not affect safety.