• 한국환경보건학회지
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• 제33권4호
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• pp.264-275
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• 2007

The objective of this study was to offer basic and scientific data for decision-making of policy for improvement and management of radon, natural radiation gas, in Korea and to form the foundation of radon related international cooperation. Therefore, this study collected and re-analysed the articles on exposure of radon in various indoor environment in journals related environment in Korea since 1980 and estimated the annual exposure dose and effective dose by exposure of radon received by inhabitants in them. The highest pooled average radon concentration of $50.17{\pm}4.08\;Bq/m^3$ (95% CI : $42.17{\sim}58.17\;Bq/m^3$) was found in dwelling house among various indoor environment. All of pooled average radon concentration estimated in this study showed lower than the guideline concentration ($148\;Bq/m^3)$ of US EPA and the Korean Ministry of Environment. The annual effective dose received by inhabitants in various indoor environment was estimated 1.071 mSv/yr. That is equal to annual effective dose (1.0 mSv/yr) by exposure of radon estimated by UNSCEAR.

• 분석과학
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• 제20권6호
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• pp.460-467
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• 2007

자연계에 존재하는 $^{238}U$, $^{235}U$, $^{232}Th$ 그리고 $^{40}K$의 감마선과 베타선에 대해 토양의 흡수선량을 평가하기 위한 유효 흡수선량 환산인자를 계산하였다. 이 때 감마선과 베타선에 대한 붕괴당 에너지, 반감기, 분기율등의 핵자료들은 National Nuclear Data Center (NNDC)의 최근 자료들을 이용하였다. 본 연구에서 계산한 흡수선량 인자 및 이를 이용하여 얻은 $^{238}U$, $^{232}Th$ 그리고 $^{40}K$의 베타선과 감마선에 유효흡수선량은 1998년 Aitken의 결과와 비교적 잘 일치하였지만, $^{235}U$의 경우는 많은 차이가 있음을 확인하였다. 한국 충북 청원군 오성에 있는 선사유적지(만수리) 내의 토양에 대해 고 분해능 감마선 분광 분석 장치(HP Ge 검출기)로 지각 방사선의 감마선 스펙트럼을 측정하고, 계산된 유효 흡수선량 환산인자를 이용하여 연간방사선량을 평가하였는데, 연간방사선량이 3.8~5.9 mGy/year으로 평가되었다. 또한 Rn 이하의 붕괴 핵종을 포함하여 연간방사선량을 평가하는 경우와, 이를 포함하지 않고 연간방사선량을 평가하는 경우는 9~30 % 차이를 나타내었다. 이 흡수선량 환산인자로 토양에 존재하는 자연 방사성 동위원소들의 베타선과 감마선에 대한 유효 흡수선량 평가법이 확립하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제41권6호
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• pp.573-580
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• 2018

The Nuclear Safety Commission amended the Nuclear Safety Act by strengthening the safety management system for the frequent workers to the level of radiation workers. And students entering radiation management zones for testing and practical purposes are subject to frequent workers. It is inevitable that this will incur additional costs. In this paper, the validity of the amendment to the Nuclear Safety Act was to be assessed in terms of radiation protection. Study subjects are from 2014 to 2016, among university students in Seong-nam Korea and comparisons for analyses were made taking into account variables that are differences in annual, practical types, on-class and clinical practice students exposure dose. The analysis showed that exposures between on-class and clinical practice received were less than the annual dose limit of 1 mSv for the public. Then, some alternatives that excluding from frequent workers during on-class practice or mitigating the frequent workers' safety regulation for only on-class frequent workers can be considered. Optimization is how rational is the reduction in exposure dose to the costs required. Therefore, the results are hardly considered for optimization. If the data accumulated, it could be considered that the revision of the act could be evaluated and improved.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2050-2056
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• 2024

Handling of radioisotopes may cause external and internal contamination to occupational workers while using radiation for medical purposes. This research aims to monitor the internal hazard of occupational workers who handle ¹³¹I. Two methods are used: in vivo or direct method and in vitro or indirect method. The in vivo or direct method was performed by assessing thyroid intake with a thyroid uptake monitoring machine. The in vitro or indirect method was performed by assessing urine samples with the help of a gamma-ray spectroscopy practice using a High-Purity Germanium (HPGe) Detector. In this study, fifty-nine thyroid counts and fifty-nine urine samples were collected from seven occupational workers who were in charge of ¹³¹I at the National Institute of Nuclear Medicine and Allied Sciences (NINMAS), Dhaka. The result showed that the average annual effective dose of seven workforces from thyroid counts were 0.0208 mSv/y, 0.0180 mSv/y, 0.0135 mSv/y, 0.0169 m Sv/y, 0.0072 mSv/y, 0.0181 mSv/y, 0.0164 mSv/y and in urine samples 0.0832 mSv/y, 0.0770 mSv/y, 0.0732 mSv/y, 0.0693 mSv/y, 0.0715 mSv/y, 0.0662 mSv/y, 0.0708 mSv/y.The total annual effective dose (in vivo and in vitro method) was found among seven workers in average 0.1039 mSv/y, 0.0950 mSv/y, 0.0868 mSv/y, 0.0862 mSv/y, 0.0787 mSv/y, 0.0843 mSv/y, 0.0872 mSv/y. Following the rules of the International Commission on Radiological Protection (ICRP), the annual limit of effective dose for occupational exposure is 20 mSv per year and the finding values from this research work are lesser than this safety boundary.

• 핵의학기술
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• 제14권2호
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• pp.9-16
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• 2010

본 연구는 방사성동위원소의 의학적 이용도가 증가함에 따라 의료기관 핵의학과 방사선 관계종사자의 직무 별 방사선 이용에 대한 개인 방사선 피폭선량의 실태를 파악하여, 방사선 위험에 대해 경각심을 고취시키고, 방사선 관계종사자들에게 안전관리와 합리적인 피폭선량 관리에 도움을 주고자 분석하였다. 2007년 1월 1일부터 2009년 12월 31일까지 의료기관에서 근무하는 핵의학 방사선 관계종사자로 분류되어 개인 방사선피폭선량 측정을 정기적, 연속적으로 3년 간 조사 관리된 40명의 종사자를 대상으로 직종 별, 영상실 별, 연령 별, 선량구간 별, 직무 별 관련업무를 파악하여 심부선량에 대하여 연간평균피폭선량을 각각 분석하였다. 분석법으로는 빈도분석과 ANOVA를 시행하였다. 3년 간 영상실 별 연간피폭선량은 PET 및 PET/CT 영상실이 11.06~12.62 mSv로 가장 높은 피폭선량을 보였고, 감마카메라 주사실이 11.72 mSv로 높았으며, 직종 별 연간평균피폭선량은 임상병리사가 8.92 mSv로 가장 높았고, 방사선사 7.50 mSv, 간호사 2.61 mSv, 연구원 0.69 mSv, 접수 0.48 mSv, 의사 0.35 mSv 순으로 나타났으며, 세부업무에 따른 직무별 연간평균피폭선량은 PET 및 PET/CT 업무가 12.09 mSv로 가장 높은 피폭선량을 보였으며, 감마카메라 주사실이 11.72 mSv, 싸이크로트론 관련 합성 업무 8.92 mSv, 감마카메라 영상업무 4.92 mSv, 치료 및 안전관리 2.98 mSv, 간호사 업무 2.96 mSv, 관리 업무 1.72 mSv, 영상분석 업무 0.92 mSv, 판독업무 0.54 mSv, 접수업무 0.51 mSv, 연구업무 0.29 mSv 순으로 나타났다. 선량구간 별 연간평균피폭선량은 연구대상자의 15명(37.5%)이 1 mSv이하의 선량분포와 5명(12.5%)이 1.01~5.0 mSv이하의 선량분포를 가지고 있었고, 5.01~10.0mSv에서 14명(35.0%), 10.01~20.0 mSv에서 6명(15.0%)의 분포로 분석되었다. 연령에 따른 연간평균피폭선량은 방사선사 직종에서는 25~34세 종사자가 8.69 mSv로 가장 높은 평균선량을 보였고, 근무기간에 따른 연간평균피폭선량은 방사선사 직종에서 5~9년 종사자가 9.5 mSv로 가장 높은 평균선량을 나타냈다. 고용형태에 따른 연간평균피폭선량은 정규직 임상병리사 8.92 mSv, 방사선사 7.82 mSv, 계약직 방사선사 7.55 mSv, 인턴직 방사선사 5.62 mSv, 계약직 간호사 2.61 mSv, 정규직 연구원 0.69 mSv, 접수 0.55 mSv, 의사 0.35mSv 순으로 피폭을 받는 것으로 나타났다. 이와 같은 결과로 볼 때 의료기관에서 근무하는 핵의학 방사선 관계종사자의 대부분이 현재의 방사선 안전관리가 실효성 있게 이루어지고 있었으며, 직무특성에 따라 많은 차이가 있는 것을 알게 되었다. 그러나 방사선 피폭을 최소화시키는 노력이 필요하며, 이를 위해서 체계적 교육과 합리적 피폭량 관리를 위한 체계가 필요하다고 사료된다.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1176-1179
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• 2019

Measurements of activity concentrations of radionuclides in atmospheric releases were performed in 2017-2018 at vent stacks of seven Russian nuclear power plants. The selected instruments and research methods, with detection limits significantly lower than the existing detection limit of Russian NPPs routine control, allowed to reliably determine up to 26 radionuclides. Analysis of experimental data allows to determine the list of radionuclides for calculation the effective dose rates to public and the permissible annual discharge levels for each Russian NPP. Radiocarbon is determined as major contributor for the dose from the atmospheric releases of LWGR reactors - up to 98% for EGP-6 and RBMK-1000 (Smolensk NPP) reactors. For PWR reactors (VVER) radionuclides contribution to the annual dose from atmospheric releases is more complicated, but, in general, dose is formed by tritium, $^{14}C$ and noble gases. The special monitoring results with ranking of measured radionuclides according to their contribution to the effective dose makes it possible to optimize the list of controlled radionuclides in airborne releases of Russian NPPs from 94 to 8-16 for different NPPs.

• Journal of Radiation Protection and Research
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• 제38권4호
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• pp.189-193
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• 2013

경수로 사용후핵연료 건식 중간저장시설 격납건물 크기에 따른 방사선량률 추이 분석을 위하여 격납건물 외부 벽면에서의 추정연간선량을 계산하였다. ORIGEN-ARP를 사용하여 농축도 4.5 wt%, 연소도 45,000 MWd/MTU 냉각기간 10년인 사용후핵연료를 대상으로 선원항을 생산하였으며, MCNP 코드를 사용하여 저장시설 및 격납건물에 대한 모델링 및 선량률 계산을 수행하였다. 연간선량은 격납건물 외부 벽면에서의 값으로 계산하였으며, 격납건물 벽과 최외곽 배열의 저장용기와의 간격을 50 m 이상으로 설정할 경우 10CFR72에서 제시하는 연간선량인 0.25 mSv 이하의 값이 계산되었다.

• Journal of Radiation Protection and Research
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• 제45권2호
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• pp.81-87
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• 2020

Background: Kori unit #1 is permanently shut down after a 40-year lifetime. The Nuclear Safety and Security Commission recommends establishing initial decommissioning plans for all nuclear and radwaste treatment facilities. Therefore, the Korea Atomic Energy Research Institute (KAERI) must establish an initial and final decommissioning plan for radwaste-treatment facilities. Radiation safety assessment, which constitutes one chapter of the decommissioning plan, is important for establishing a decommissioning schedule, a strategy, and cost. It is also a critical issue for the government and public to understand. Materials and Methods: This study provides a method for assessing external radiation dose to workers during decommissioning. An external dose is calculated following each exposure scenario, decommissioning strategy, and working schedule. In this study, exposure dose is evaluated using the deterministic method. Physical characterization of the facility is obtained by both direct measurement and analysis of the drawings, and radiological characterization is analyzed using the annual report of KAERI, which measures the ambient dose every month. Results and Discussion: External doses are calculated at each stage of a decommissioning strategy and found to increase with each successive stage. The maximum external dose was evaluated to be 397.06 man-mSv when working in liquid-waste storage. To satisfy the regulations, working period and manpower must be managed. In this study, average and cumulative exposure doses were calculated for three cases, and the average exposure dose was found to be about 17 mSv/yr in all the cases. Conclusion: For the three cases presented, the average exposure dose is well below the annual maximum effective dose restriction imposed by the international and domestic regulations. Working period and manpower greatly affect the cost and entire decommissioning plan; hence, the chosen option must take account of these factors with due consideration of worker safety.

• 한국안전학회지
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• 제24권6호
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• pp.157-162
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• 2009

Radioactive medicines are used a lot owing to the increase of a PET-CT examination using glucose metabolism useful for the early diagnosis of diseases. Therefore, the spatial dose that is generated from patients and their surroundings causes the patients' guardians and health professional to be exposed to radiation. However, they get unnecessarily exposed to radiation because medical institutions lack in space for isolation and recognition of the examination. This research intended to examine the spatial dose rates by measuring the dose emitted from the patient for 48 hours to whom F-18 FDG was administered. The spatial dose rates that were measured 100cm away from the patient's body after F-18 FDG was injected were $65.88{\mu}$Sv/hr at 60-minute point, $45.13{\mu}$Sv/hr at 90-minute point, $9.88{\mu}$Sv/hr at 6-hour point, and $1.24{\mu}$Sv/hr at 12-hour point. When the dose that the guardian and health professional got was converted into the annual(240-day working) accumulative dose, it was examined that the guardian received 81.56 mSv/yr and health professional received 49.36mSv/yr. In addition, the result has revealed that the dose that the patient received from one time of PET-CT examination was 3.75mSv/yr, which is 1.5 times more when compared with the annual natural radiation exposure dose.

• Journal of Radiation Protection and Research
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• 제39권4호
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• pp.159-167
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• 2014

국내에서는 2012년 천연방사성핵종이 포함된 가공제품의 규제를 위해 생활주변방사선 안전관리법이 시행되었지만, 해당 가공제품 사용에 대한 인체 피폭선량을 평가할 수 있는 기초자료나 피폭선량 평가기술이 미비하다. 따라서 본 연구는 사용자 피폭선량을 정량적으로 평가하기 위한 방법을 제안하고, 방사선의 종류 및 에너지에 따른 피폭선량 특성의 확인을 목적으로 한다. 피폭선량 평가를 위해서 몬테칼로 방법을 사용한 Monte Carlo N-Particle Extended (MCNPX) 코드를 통해 International Commission on Radiological Protection (ICRP)의 기준팬텀이 전산모사 되었으며, 대표적 천연방사성핵종인 우라늄 계열에서 발생되는 알파선, 베타선, 감마선의 최소, 중간, 최대 에너지가 선원항으로 사용되었다. 연간 유효선량은 가공제품 사용시간 및 사용위치를 고려한 피폭시나리오를 기반으로 평가되었다. 짧은 비정의 알파선 및 베타선은 대부분의 선량을 피부에 전달한 반면, 감마선은 대부분의 장기에 유사한 선량을 전달하였다. 방사능이 $1Bq{\cdot}g^{-1}$ 인 돌침대에 포함된 천연방사성핵종의 함유율이 10%라고 가정하고 한국인 평균 수면시간인 7시간 50분간 돌침대를 사용하였을 때 최대 연간 유효선량은 알파선, 베타선, 감마선에 대해서 각각 0.0222, 0.0836, $0.0101mSv{\cdot}y^{-1}$로 평가되었다.