• Journal of Radiation Protection and Research
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• v.7 no.1
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• pp.1-10
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• 1982

For the purpose of establishment of Reference Korean and estimation of internal and external exposure doses in the Reference Korean, we have surveyed reference values for Koreans, such as physical standards including height, weight and body surface area, food consumption rate of daily intake of radioactive substances and exposure dose from natural radiation. The results obtained are as follows: 1) The age group of the Reference Korean ranged from 20 to 30 years old in both sexes. The height, weight and surface area of the body of the Reference Korean are 167cm, 61kg and $1.67m^2$ in male and 155cm, 51kg and $1.51m^2$, respectively in female. 2) The food consumption of the Korean is 812.8g (669.6g of vegetable food and 143.2g of animal food) per capita per day. 3) Koreans are taken about 1,200 pCi of radioactive substances(${\beta}$-ray) per capita per day. 4) The external and internal radiation exposure doses of the Korean are estimated to be 127 mrem and 8 mrem per year, respectively. However, it is believed that these values will be modified upon the addition of data collection.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.412.2-412
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• 2002

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.207-213
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• 2003

Carbon-14 is one of the major radionuclides released by CANDU Nuclear Power Plants(NPPs). It is almost always emitted as gas through the stack. From CANDU NPPs about 95% of all carbon-14 is released as carbon dioxide. Carbon-14 is a low energy beta emitter which, therefore, gives only a small skin dose from external radiation. As carbon dioxide Is physiologically rather inert gases for man's metabolism, the inhalation dose is probably less than 1 % of the ingestion dose. But this source of carbon-14, formed in a closed, nor-oxidative environment, was subsequently released into the workplace as an insoluble particulate when these systems were opened lip for re-tubing at CANDU NPPs. As a part of the improvement of dosimetry program at Wolsong Nuclear Power Plants, the carbon-14 metabolism based on references was investigated and studied to setup the internal dosimetry program due to inhalation of carbon-14.

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.321-325
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• 2003

The effects of AMAD, absorption type, and intake pattern were compared and analysed for the internal dose evaluation of workers who chronically inhale uranium. The committed effective doses$(E_{50})$ based on AMAD, absorption type, and intake pattern were evaluated using 3 monthly lung predicted monitoring data due to a chronic intake of uranium for 5 years. The relative error ranges of $E_{50}$ evaluated with each AMAD$(0.1{\sim}10{\mu}m)\;to\;E_{50}$ evaluated with $5{\mu}m$ AMAD were $-37.0{\sim}49.8%$, and the relative error ranges of En evaluated with Type M to $E_{50}$ evaluated with Type S were $15.9{\sim}56.6%$, and the relative error ranges of $E_{50}$ evaluated with an acute intake to $E_{50}$ evaluated with a chronic intake were $0.55{\sim}4.52%$. Thus AMAD and the absorption type affected the results of $E_{50}$, but the intake pattern didn't really affect the results of $E_{50}$.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.377-383
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• 2017

The purpose of this study was to evaluate the distribution of spatial scatter ray on the chest radiographs of patients on health examination bus. In this paper, we propose a method for minimize unnecessary exposure by measuring the scattered dose after exposure the actual subject and comparing the body mass index (BMI) with the tube current amount mAs. The results of this study showed that the mean BMI of the subjects was $23.31{\pm}3.12$. The mean mAs value was $2.92{\pm}1.19$, which males was higher than females. The mean value of the scatter ray at position 1 in the radiography room was $771.81{\pm}151.15{\mu}Sv/hr$. The mean value of the scatter rays at the position 2 outside the entrance of the radiography room was measured as $53.86{\pm}25.66{\mu}Sv/hr$. As the BMI and mAs was increase the spatial scatter dose was increased at position 1 and position 2 in the photographing room. In order to minimize the exposure dose of scatter ray, radiation workers should shoot the radiation as low as possible within the range that does not impair the quality of the image. It will be necessary to make efforts to not wait for a waiting person near the entrance door of the photographing room.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.53-59
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• 2004

A variety of factors such as the pattern of intake (acute or chronic), monitoring interval and the characteristics of the radionuclides could have a significant influence on the estimates for the intake and internal dose. The relative differences of the assessed intakes based on the assumption of an acute intake to that of a chronic intake were evaluated by using the predicted bioassay quantity in the whole body or organs for an acute and chronic intake through the inhalation of $^{125}$ I, $^{137}$ C, $^{235}$ U with the AMAD of 1 ${\mu}{\textrm}{m}$ and 5 ${\mu}{\textrm}{m}$ for the monitoring intervals of 7, 14, 30, 60, 90, 120, 180, 360 days, respectively, The relative difference of the assessed intakes based on the intake pattern is affected by the monitoring interval, radionuclide and absorption type, but the particle size has little influence on the difference of the assessed intakes based on the intake pattern. The maximum monitoring interval, which is defined as the monitoring interval that the relative difference of the assessed intakes based on the assumption of an acute intake to that of a chronic intake is less than 10%, is 60 d for $^{125}$ I with Type F, 180 d for $^{137}$ C with Type F, 90 d for $^{235}$ U with Type M, and 360 d for $^{235}$ U with Type S. It was concluded that an intake pattern has little influence on the estimates of the assessed intake in the case where the monitoring interval is shorter than the maximum monitoring interval for each radionuclide.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.657-665
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• 2017

The aim of this study was to develop and distribute a dedicated program that can easily calculate the effective dose of a patient undergoing nuclear medicine examinations, and assist in the study of dose of nuclear medicine examinations and information disclosure. The program produced a database of the effective dose per unit activity administered (mSv/MBq) of the radiopharmaceuticals listed in ICRP 80, 106 Report and the fourth addendum, was designed through Microsoft Visual Basic (In Excel) to take the effect of 5 different (Area, Clark, Solomon(=Fried), Webster, Young) of pediatric dose calculation methods and 7 different body surface area calculation methods. The program calculates the effective dose (mSv) when the age, radionuclide, substance, and amount injected in the human body is inputted. In pediatric cases, when the age is entered, the pediatric method is activated and the pediatric method to be applied can be selected. When the BSA (Body Surface Area) formula is selected in the pediatric calculation method, a selection window for selecting the body surface area calculation method is activated. When the adult dose is input, the infant dose and the effective dose (mSv) are calculated automatically. The patient effective dose calculation program of the nuclear medicine examinations produced in this study is meaningful as a tool for calculating the internal exposure dose of the human body that is most likely to be obtained in nuclear medicine examinations, even though it is not the actual measurement dose. In the future, to increase the utilization of the program, it will be produced as an application that can be used in mobile devices, so that the public can access it easily.

• Journal of Radiation Protection and Research
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• v.34 no.2
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• pp.87-94
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• 2009

Tritium is the one of the dominant contributors to the internal radiation exposure of workers at pressurized heavy water reactors (PHWRs). This nuclide is likely to release to work places as tritiated water vapor (HTO) from a nuclear reactor and gets relatively easily into the body of workers by inhalation. Inhaled tritium usually reaches the equilibrium of concentration after approximately 2 hours inside the body and then is excreted from the body with a half-life of 10 days. Because tritium inside the body transports with body fluids, a whole body receives radiation exposure. Internal radiation exposure at PHWRs accounts for approximately 20-40% of total radiation exposure; most internal radiation exposure is attributed to tritium. Thus, tritium is an important nuclide to be necessarily monitored for the radiation management safety. In this paper, metabolism for tritium is established using its excretion rate results in urine samples of workers at PHWRs and an effective half-life, a key parameter to estimate the radiation exposure, was derived from these results. As a result, it was found that the effective half-life for workers at Korean nuclear power plants is shorter than that of International Commission on Radiological Protection guides, a half-life of 10 days.

• Journal of Radiation Protection and Research
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• v.13 no.2
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• pp.41-51
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• 1988

In order to develop a food-chain computer code suitable to the environmental conditions of Korea, the FOOD III code was partially modified. The excution results for Korean male-adult were compared to those from the Canadian version of FOOD III to deduce a more realistic approach in dose assessment. The amounts of Mn-54, Co-58, Co-60, I-131 and I-132 released from Kori unit 1 in1984 were used as the source terms for the sample calculation. The maximum atmospheric dispersion factor(X/Q) value on the site boundary was applied. Through the code modification, organ doses decreased by about $20{\sim}70%$ and the effective committed dose equivalent by about 40% to be $7.935{\times}10^{-6}Sv/y$ which is 0.16% of the ICRP limit, $5{\times}10^{-3}Sv/y$.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.41-44
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• 2010

Purpose: Along with recent advances in PET/CT instrumentation and imaging technology, the number of patients has also been steadily increasing. This resulted in the increased radiation exposure to radiation workers in PET/CT rooms. In this study, we installed a radiation shield and investigated whether it could reduce radiation exposure to the workers and thus enhance job satisfaction. Materials and Methods: A radiation shield is composed of 5 cm thick lead and has a structure in which a radiation worker sits and watches a patient through lead glass while injecting radiopharmaceutical to the patient. Quarterly absorbed dose of radiation workers was measured using thermoluminescence dosimeters (TLD) and the results were compared for six months each before and after installation of the radiation shield. Exposure dose was also measured using a pocket dosimeter placed at the same location in the front and the back of the radiation shield. In addition, frequency of use of the shield and job satisfaction of radiation workers were investigated using a survey. Results: Quarterly absorbed dose of radiation workers was 2.70 mSv on average before installation of new radiation shield, whereas that dropped to 2.13 mSv after installation of radiation shield, reducing radiation exposure dose by 21%. Exposure dose on the front side of the shield was 61.2 R, whereas that on the back side of shield was 2.8 R. According to the survey, 85% of workers used the shield and were satisfied with the outcome: each radiation worker made injections to patients average of 6.5 times/day and preferred sitting to standing while injecting radiopharmaceutical to patients. Conclusion: Use of radiation shield reduced the exposure dose of radiation workers, which is the ultimate goal of radiation protection to minimize radiation exposure and is an appropriate method for the improvement of hospital working environment. Furthermore, we found that use of radiation shield not only relieves physical and psychological burden of radiation workers but also enhances job satisfaction. This result indicates that use of radiation shield is important for improvement of the radiation workers' job environment in terms of radiation protection.