• 환경영향평가
• /
• 제22권1호
• /
• pp.89-97
• /
• 2013

RADCONS Ver. 1.0 (RADiological CONSequence Assessment Program) was developed for radiological risk assessment in this study. A Gaussian plume model was used to analyze the fate and transport of radionuclides released into the air in case of accidents. Both single meterological data and time series meterological data can be used in RADCONS. To assess the radiological risk of the early phase after an accident, ED (Effective Dose) estimated by both deterministic and probabilistic approaches are presented. These EDs by deterministic and probabilistic will be helpful to efficient decision making for decision makers. External doses from deposited materials by time are presented for quantifying the effects of mid and late phases of an accident. A radiological risk assessment was conducted using RADCONS for an accident scenario of 1 Ci of Cs-137. The maximum of ED for radii of 1,000 meters from the accident point was 8.51E-4 mSv. After Monte-Carlo simulation, considering the uncertainty of the breathing rate and dispersion parameters, the average ED was 8.49E-4, and the 95 percentile was 1.10E-3. A data base of the dose coefficients and a sampling module of the meteorological data will be modified to improve the user's convenience in the next version.

• Nuclear Engineering and Technology
• /
• 제52권8호
• /
• pp.1784-1791
• /
• 2020

The 14 MeV neutron generator facility is being developed by the Institute for Plasma Research India to conduct the lab scale experiments related to Indian breeding blanket system for ITER and DEMO. It will also be utilized for material testing, shielding experiments and development of fusion diagnostics. Occupational radiation exposure control is necessary for the all kind of nuclear facilities to get the operational licensing from governing authorities and nuclear regulatory bodies. In the same way, the radiation exposure for the 14 MeV neutron generator facility at the occupational worker area and accessible zones for general workers should be under the permissible limit of AERB India. The generator is designed for the yield of 10¹² n/s. The shielding assessment has been made to estimate the radiation dose during the operational time of the neutron generator. The facility has many utilities and constraints like ventilation ducts, accessible doors, accessibility of neutron generator components and to conduct the experiments which make the shielding assessment challenging to provide proper safety for occupational workers and the general public. The neutron and gamma dose rates have been estimated using the MCNP radiation transport code and ENDF -VII nuclear data libraries. The ICRP-74 fluence to dose conversion coefficients has been used for the assessment. The annual radiation exposure has been assessed by considering 500 h per year operational time. The provision of local shield near to neutron generator has been also evaluated to reduce the annual radiation doses. The comprehensive results of radiation shielding capability of neutron generator building and local shield design have been presented in the paper along with detailed maps of radiation field.

• 한국임상약학회지
• /
• 제27권3호
• /
• pp.127-135
• /
• 2017

Background: Kawasaki disease (KD) is an acute febrile, systemic vasculitis as a leading cause of acquired heart disease in children. Intravenous immunoglobulin G (IVIG) and aspirin are the standard initial therapy in the treatment of acute KD. The purpose of this study was to investigate drug utilization in children with KD, and to compare "IVIG + high-dose aspirin" and "IVIG + moderate-dose aspirin" in preventing cardiac complications. Methods: We analyzed pediatric patient sample data compiled by the Health Insurance Review & Assessment Service from 2010 to 2015. We identified patients with KD using the KCD-6 code of M30.3. We excluded patients in chronic phase or ${\geq}1$0 years. We also excluded patients who were diagnosed KD in November or December. Drug utilization pattern were assessed in acute KD patients and 30-day and 60-day cardiac complications were investigated between "IVIG + high-dose aspirin" group and "IVIG + moderate-dose aspirin" group. Results: In acute phase, IVIG was administered to 95.8% patients, and 57.1% patients were prescribed moderate-dose aspirin and 25% patients were with high-dose aspirin. Steroid use was rapidly increased from 4.0% in 2010 to 11.3% in 2015. Both 30-day and 60-day cardiac complications occurred less in "IVIG + high-dose aspirin" group compared to "IVIG + moderate-dose aspirin" group, but not statistically significant (0.9% vs 1.8%, p=0.252 for 30-day complication rate; 1.5% vs 2.7%. p=0.073 for 60-day complication rate). Conclusion: We were not able to demonstrate which aspirin therapy is superior for preventing cardiac complications in acute KD patients and further research is warranted.

• Journal of Radiation Protection and Research
• /
• 제43권2호
• /
• pp.50-58
• /
• 2018

Background: In terms of the Level 3 probabilistic safety assessment (Level 3 PSA), ingestion of food that had been exposed to radioactive materials is important to assess the intermediate- and long-term radiological dose. Because the ingestion dose is considerably dependent upon the agricultural and dietary characteristics of each country, the reliability of the assessment results may become diminished if the characteristics of a foreign country are considered. Thus, this study intends to evaluate and analyze the ingestion dose of Korean during a severe accident by completely considering the available agricultural and dietary characteristics in Korea. Materials and Methods: This study uses COMIDA2, which is a program based on dynamic food chain model. It sets the parameters that are appropriate to Korean characteristics so that we can evaluate the inherent ingestion dose of Korean. The results were analyzed by considering the accident date and food category with regard to the $^{137}Cs$. Results and Discussion: The dose and contribution of the food category depicted distinctive differences based on the accident date. Particularly, the ingestion dose during the first and second years depicted a considerable difference by the accident date. However, after the third year, the effect of foliar absorption was negligible and exhibited a similar tendency along with the order of root uptake rate based on the food category. Conclusion: In this study, the agricultural and dietary characteristics of Korea were analyzed and evaluated the ingestion dose of Korean during a severe accident using COMIDA2. By considering the inherent characteristics of Korean, it can be determined that the results of this study will significantly contribute to the reliability of the Level 3 PSA.

• 한국의학물리학회지:의학물리
• /
• 제28권2호
• /
• pp.45-48
• /
• 2017

This paper evaluated the amount of radiation generated by wedge filters during radiation therapy using a high-energy linear accelerator, and the dose to the worker during wedge replacement. After 10-MV photon beam was irradiated with wedge filter, the wedge was removed from the linear accelerator, and the dose rate and energy spectrum were measured. The initial measurement was approximately 1 uSv/h, and the radiation level was reduced to 0.3 uSv/h after 6 min. The effective half-life derived from the dose rate measurement was approximately 3.5 min, and the influence of AI-28 was about 53%. From the energy spectrum measurements, a peak of 1,799 keV was measured for AI-28, while the peak for Co-58 was not measured in the control room. The peaks for Au-106 and Cd-105 were found only measurement was done without wedge removement from the linear accelerator. The additional doses received by the radiation worker during wedge replacement were estimated to be 0.08-0.4 mSv per year.

• 환경생물
• /
• 제34권3호
• /
• pp.193-200
• /
• 2016

해산로티퍼 (Brachionus plicatilis)의 생존율 및 개체군 성장률을 사용하여 중금속 As, Cr 및 Pb에 대한 독성평가를 수행하였다. 중금속에 24시간 노출한 생존율은 As와 Cr의 30과 $150mg\;L^{-1}$ 농도에서 급격한 감소가 시작되어 농도의존적으로 감소하였으나, Pb에서는 영향이 나타나지 않았다. 중금 속에 72시간 노출한 개체군 성장률은 As, Cr 및 Pb의 5, 25 및 $50mg\;L^{-1}$ 농도에서 급격한 감소가 시작되어, 3종 중금속에서 모두 농도의존적으로 감소하는 경향을 보였다. As, Cr 및 Pb에 노출된 개체군 성장률의 $EC_{50}$ 값은 각각 12.98, 82.34 및 $110.14mg\;L^{-1}$이고 독성의 세기는 As>Cr>Pb로 생존율과 동일하였다. 또한 As, Cr 및 Pb에 대한 개체군 성장률의 NOEC는 각각 1, 12.5 및 $50mg\;L^{-1}$, LOEC는 각각 5, 25 및 $50mg\;L^{-1}$로 나타났다. 해양환경에서 각각의 LOEC 이상의 농도는 B. plicatilis에게 독성영향을 미칠 수 있는 농도로 판단되며, NOEC와 $EC_{50}$ 값은 WET test를 위한 혼합독성과 해양생태계 내 중금속독성에 대한 가이드라인으로 적절하게 활용될 수 있을 것이다.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1995년도 추계학술발표회논문집(2)
• /
• pp.879-884
• /
• 1995

The results of performance assessment analyses have shown that the long-lived radionuclides such as I-129 control the potential individual dose impact to the public. I-129 is difficult-to-measure(DTM) in low-level waste because it is non-gamma emitting radionuclides and exists at extremely low concentrations in radioactive waste generated by nuclear reactors. In this study, computer modeling technique to predict release rate of I-129 is developed to provide another tools far performance assessment of land disposal facilities and characteristics of radwaste. Model suggested in this study will give conservative values of I-129 release rate far determination of radwaste characteristics. More detailed approach is implemented to account for release conditions of fuel source-nuclides. 1-131 concentration measured from reactor coolant and released fraction from tramp fuel have dominant roles in calculating release rate of I-129 with fuel defect conditions.

• Journal of Radiation Protection and Research
• /
• 제24권2호
• /
• pp.101-108
• /
• 1999

극저준위 방사성액체폐기물 처리를 위하여 공기의 온도와 습도 및 유입 공기의 속도에 따른 증발량의 관계를 천을 이용한 강제증발실험 장치로 실험하였다. 그 결과 각각의 변수와 증발량의 상관관계를 실험식으로 도출하였다. 또한 Cs-137 을 함유한 모의폐액을 사용하여 본 장치에 대한 제염 계수를 얻은 결과 $DF=10^4$으로 나타났다. TRlGA Mark II & III 연구용 원자로 폐로시 발생되는 극저준위 방사성액체폐기물을 증발장치로 처리할 때 주변의 일반개인에 대한 연간 피폭선량을 보수적으로 평가한 결과, 유효선량 (effective dose)은 $1.01{\times}10^{-3}mSv$이고, 환경으로 배출되는 공기의 방사능 농도(Cs-137)는 $4.637{\times}10^{-14}\;{\mu}Ci/cc$ air 이다. 따라서 극저준위 방사성액체폐기물의 처리를 위하여 강제증발장치를 사용하는 것은 주민에 아무런 영향이 없음을 알 수 있었다.

• Journal of Radiation Protection and Research
• /
• 제26권3호
• /
• pp.291-298
• /
• 2001

The designed release rate of liquid effluents from radwaste treatment system should be calculated and evaluated during normal operation, including anticipated operational occurrence and be assured that the release concentration and off-site dose at unrestricted area do not exceed the limits of regulation. The expected annual release rate and off-site dose for the currently operating nuclear power plants in Korea had been calculated and evaluated using PWR-GALE and LADTAP-II which was based on USNRC Regulatory Guide 1.109. Recently, the MOST Notice 2001-2 related to release concentration and off-site dose at unrestricted area was revised to reflect the concept of ICRP-60. It is necessary for KORI 3&4 to re-calculate the release concentration and off-site dose and to compare these results with the limits of regulation. As the results of assessment, we confirmed that the release concentrations were less than its limits of MOST Notice 2001-2 and the off-site dose at unrestricted area using K-DOSE60 was 3.61E-03 mSv/yr to the age of five for the effective dose, and 4.10E-2 mSv/yr to thyroid of the age of five for the organ equivalent dose. We also confirmed the off-site dose was within the limits of MOST Notice 2001-2. Therefore, the release concentration and off-site dose re-evaluated at unrestricted area in KORI 3&4 were well below the regulation limits of MOST Notice 2001-2.

• Journal of Radiation Protection and Research
• /
• 제41권1호
• /
• pp.1-6
• /
• 2016

Background: It is very difficult to set a regulatory guidance or criteria for the protection of non-human species from the ionizing radiation, because there are no generally or internationally accepted methods for demonstrating the compliance with such criteria. It is needed that Korea develop the primary dose rate standards for the protection of both aquatic and terrestrial biota in the near future. Materials and Methods: The potential dose rates due to both external and internal radiation exposures to marine organisms such as plaice/flounder, gray mullet, and brown seaweed collected within territorial seas around the Korean Peninsula were estimated. Results and Discussion: The total dose rates to plaice/flounder, gray mullet and brown seaweed due to $^{40}K$, a primordial radionuclide in marine environment, were found to be 0.2%, 0.08% and 0.3% of approximately the values of the Derived Consideration Reference Levels (DCRLs, i.e. $1-10mGy{\cdot}d^{-1}$), respectively, as suggested by the International Commission on Radiological Protection (ICRP) publication 124. The total dose rates to marine fishes and brown seaweed due to anthropogenic radionuclides such as $^{90}Sr$, $^{137}Cs$ and $^{239+240}Pu$ were considered to be negligible compared to the total dose rate due to $^{40}K$. The external exposure to benthic fish due to all radionuclides was much higher than that of pelagic fish. Conclusion: From this study, it is recommended that the further study is required to develop a national regulatory guidance for the evaluation of doses to non-human species.