• Journal of Radiation Protection and Research
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• v.32 no.3
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• pp.111-115
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• 2007

A deuterium oxide leakage accident occurred on October 4, 1999, at nuclear power plant in Korea. The concentration of tritium in air increased and 22 workers were exposed by tritium at that time. It is well known that tritium causes internal exposure. Therefore, we examined complete blood cell count, physical and biological dosimetry fur 13 workers among whole 22 workers to check the health effect and to evaluate the dose estimation of tritium exposure. The leukocyte count test, one of general blood test, was normal. The estimated doses were 0 - 4.44 mSv by physical dosimetry and 0-37 mGy by biological dosimetry. This dose does not exceed radiation dose limit, and the clinical symptoms of the exposed workers were not shown. The consistency between clinical sign and estimated dose means that physical and biological dosimetry were very useful especially in accident evaluation.

• Journal of Radiation Protection and Research
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• v.47 no.2
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• pp.93-98
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• 2022

Background: This study aims to derive the characteristics of each work type for industrial radiography based on empirical evidence through expert advice and a survey of radiation workers of various types of industrial radiography. Materials and Methods: According to a Korean report, work types of industrial radiography are classified into indoor tests, underground pipe tests, tests in a shielded room (radiographic testing [RT] room test), outdoor field tests, and outdoor large structure tests. For each work type, exposure geometry and radiation sources were mainly identified through the expert advice and workers' survey as reliable empirical evidence. Results and Discussion: The expert advice and survey results were consistent as the proportion of the work types were high in the order of RT room test, outdoor large structure test, underground pipe test, outdoor field test, and indoor test. The outdoor large structure test is the highest exposure risk work type in the industrial radiography. In most types of industrial radiography, radiation workers generally used ¹⁹²Ir as the main source. In the results of the survey, the portion of sources was high in the order of ¹⁹²Ir, X-ray generator, ⁶⁰Co, and ⁷⁵Se. As the exposure geometry, the antero-posterior geometry is dominant, and the rotational and isotropic geometry should be also considered with the work type. Conclusion: In this study, through expert advice and a survey, the external exposure characteristics for each work type of industrial radiography workers were derived. This information will be used in the reconstruction of organ dose for health effects assessment of Korean radiation workers.

• The Korean Society of Law and Medicine
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• v.22 no.3
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• pp.97-124
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• 2021

In medical institutions, there are radiation-related workers such as radiological technologists, physicians, dentists, and dental hygienists who handle diagnostic radiation generators. Also, there are work assistants, such as nurses and assistant nurses, who assist in radiation treatment or transfer patients to the radiation examination room. Radiation exposure management for radiation-related workers is carried out under the 「Medical Service Act」, but there is no legal basis for work assistants, etc. And the management of radiation exposure for diagnosis is regulated by the 「Medical Service Act」, and the management of radiation exposure by therapeutic radiation and nuclear medical examination is governed by the 「Nuclear Safety Act」. Thus, to improve the management of radiation exposure for diagnosis, the regulations on radiation exposure management for diagnosis under the 「Medical Service Act」 were compared and reviewed with those of the 「Nuclear Safety Act」. As a result, the main contents are as follows. First, it is necessary to legislate to include nurses, assistant nurses, and clinical practice students who are likely to be exposed to radiation besides radiationrelated workers as subjects of radiation exposure management for diagnosis. Second, when a radiation-related worker for diagnosis is confirmed to be pregnant, the exposure dose limit should be defined. Third, it is necessary to revise the regulations on the types of personal exposure dosimeters in the 「Rules on the Safety Management of Radiation Generators for Diagnostics」. Fourth, it seems that health examination items for radiation-related workers, radiation workers, and frequent visitors should be the same. Fifth, It is necessary to unify and regulate diagnostic radiation and all medical radiation, including therapeutic radiation and nuclear medicine, in one legal system.

• Journal of Radiation Protection and Research
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• v.29 no.3
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• pp.179-186
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• 2004

A single-dosimeter worn on the anterior surface of body of a worker was found to provide significant underestimation of dose to the worker when radiation comes from behind of the human body. Recently, several researchers suggested that this kind of underestimation can be corrected to a certain extent by using an extra dosimeter on the back. But this multiple dosimetry also has the disadvantages like overestimation lowering work efficiency or cost burden. In this study, a single dosimeter introducing asymmetric filters enabled to identify PA exposure was designed by monte-carlo simulation and experiments and its dose evaluation algorithm for AP-PA mixed radiation field was established. This algorithm was applicable to penetrating radiation which had the effective energy more than 100 keV. Besides, the dosimeter and algorithm in this study were possible to be applied to near PA exposure.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.155-159
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• 2013

Late effects of chronic exposure to gamma radiation are potential hazards to worker in radiation facilities as well as to the general public. Recently, chronic gamma radiation exposure effects have become a serious concern. Using a total of 60 mice, we studied the biological effects of medium-dose chronic exposure to gamma radiation. Sixty female 6-week-old specific pathogen free Balb/c mice were randomly divided into six groups (five groups irradiated and one non-irradiated control group). Irradiation was carried out for 7 days using gamma rays at dose rates of 119.65, 238.10, 357.14, 476.19 and $595.24mGy\;h^{-1}$ with total doses 20, 40, 60, 80 and 100 Gy. After irradiation, we determined survival rate of gamma radiation exposed mice during 1 week and 476.19 and $595.24mGy\;h^{-1}$ exposed group mice showed less 10% of survival rate. Otherwise, 119.65, 238.10 and $357.14mGy\;h^{-1}$ exposed group mice were survived each 100%, 80% and 70%. Half of survived mice after 1 week are immediately sacrifice and counted body and spleen weights. Compared with control non-irradiated group, total body weights and spleen weights isolated from 119.65, 238.10 and 357.14 irradiated group mice showed significant decreased. However, no significant alteration was observed between 119.65, 238.10 and $357.14mGy\;h^{-1}$ irradiated group. Overall, our results show for the first time that medium-dose chronic gamma radiation has the potential to stimulation of biological effects.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.267-275
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• 2023

Occupational exposure records are subject of global interest, and analysis of radiation workers in work categories is being conducted. In Rep. of Korea, according to relevant ministries, the MOHW(Ministry of Health and Welfare), the MAFRA(Ministry of Agriculture, Food and Rural Affairs), and the NSSC(Nuclear Safety and Security Commission) collect and analyze records of occupational exposure by dividing them into 11 work categories. However, this classification system lacks consistency with the systems of major countries, including the UNSCEAR(United Nations Scientific Committee on the Effects of Atomic Radiation). The domestic radiation work field classification system does not have clear classification criteria and does not reflect the characteristics of the radiation work field. Through the analysis of the classification system of the UNSCEAR, we suggested the five main categories(nuclear cycle, medical, industrial, others(education/research, military/public) field and several sub-categories according to each radiation work field.

• Journal of Radiation Industry
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• v.9 no.1
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• pp.47-55
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• 2015

Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higer in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workes. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum $50mSv\;y^{-1}$). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the furture. Should try to minimize the radiation individual dose of radiation workers.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.87-94
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• 2005

Purpose : Heavy metal use when producing the block from the workshop. At this time, production of heavy metal dust and fume gives risk in human. This like heavy metal to improve seriousness through measurement and analysis. And by the quest in solution is purpose of this thesis. Materials and Methods : Organization is Inductively Coupled Plasma Atomic Emission Spectrometer, and the object is Deajeon city 4 workshops in university hospital radiation oncology (Bismuth, Lead, Tin and cadmium). Method is the ppb the pumping it does at unit, comparison analysis. And the Calculation heavy metal standard level in air through heavy metal standard level in body and blood, so Heavy metal temporary standard set. Results : Subterranean existence room air quality the administration laws appointed Lead and Cadmium's exposure recommend that it is $3{\mu}g/m^3\;and\;2{\mu}g/m^3$. And Bismuth and Tin decides $7{\mu}g/m^3\;and\;6{\mu}g/m^3$ through standard level in air heavy metal and standard level in body and blood. Heavy metal measurement level of workshops in 4 university hospital Daejeon city compares with work existence and nonexistence. On work nonexistence almost measurement level is below the recommend level. But work existence case express high level. Also consequently in composition ratio of the block is continuous with the detection ratio. Conclusion : Worker's heavy metal contamination imbrued serious for solution founds basic part. In hospital may operation on local air exhauster and periodical efficiency check, protector offer, et al. And worker have a correct understanding part of heavy metal contamination, and have continuous interest, health control. Finally, learned society sphere administer to establishment standard level and periodical measurement. And it founds basic solution plan of periodical special health checkup.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2063-2065
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• 2003

The control rod drive mechanisms in a reactor head are arranged too narrow for a human worker to approach. Moreover, the working environment is in high radiation area. In order to inspect defections in the surfaces of the reactor head and welding parts, a visual inspection device that can approach such a narrow and high radiation area is required. This paper introduces a tele-operated mobile robot for visual inspection of a reactor head, which has pan/tilt camera, fixed rear camera, ultrasonic collision detection system, and so on. Moreover, the host controller and digital video logging system are developed and integrated control software is also developed. The robot is operated by a wireless control, which gives flexibility for the inspection.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.581-587
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• 2023

In this study, we tried to provide basic data for radiation safety management by comparing and analyzing the exposure doses of radiation workers and frequent workers at C University Hospital in Incheon. From January 2021 to December 2022, surface dose and deep dose were analyzed for 30 radiation workers and 8 frequent workers who worked at C university hospital in Incheon. Radiation workers were targeted at radiation technicians and nurses working in the radiation oncology department and nuclear medicine department, and frequent visitors were targeted at frequent workers who manage and clean facilities in the same radiation management area. In the radiation worker group, 3.1 per 10,000 radiation technologist, 1.2 per 100,000 nurses, and 4.5 per 1,000,000 frequent workers showed the possibility of developing side effects on the lungs. The probability of radiation oncology was 1.1 per 10,000 for radiation technologist and 5.2 per 1,000,000 for nurses, and the probability of radiation technologist in nuclear medicine was 2.9 per 10,000 and for nurses was 7.1 per 1,000,000. It is hoped that this study can be used as basic data in future revisions on frequent workers, and it is considered that it will be used as basic data in the field of obstacles in relation to the stochastic effect of radiation in the future.