• Korean Journal of Digital Imaging in Medicine
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• v.3 no.1
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• pp.76-84
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• 1997

We tried to find any factor to reduce the exposure dose with ST-VA type generator which has the higher exposure dose. The guideline recommended by the provisions of IAEA regulation is being used at the time of radiation exposure and almost of those equipments used for this study had less amount of doses than those in the guideline. The FCR may be possible to decrease a certain amount of dose with effective applications of it's automatic image compensation utilities and the verifying function in PACS. Next time, it is required to add a great number of hospitals for wide range of studios and measurements, and make standard exposure Control table which will bing in practice, material decrease of dose volumes when radiation exposure.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.583-589
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• 1996

원자력발전소에서 발생되는 방사성폐기물들은 폐기물형태 및 방사능 농도가 다양하며 영구처분장으로 이송전까지는 발전소내의 임시 저장고에 안전하게 보관, 관리하고 있다. 생성된 폐기물드럼내에는 감마방출핵종을 비롯하여 알파 및 베타방출 핵종들이 균질 또는 비균질하게 존재하고 있으며 방사능의 세기나 폐기물의 특성에 따라 안정화시키거나 압축처리하여 드럼에 담겨져 있기 때문에 일반적인 파괴분석에 의한 화학분석법으로는 작업자의 피폭, 시료의 대표성 선정 및 장시간의 화학처리 시간소요 등으로 핵종분석이 곤란하다. 따라서 본 논문은 일반적으로 감마핵종분석시 흔히 사용하고 있는 고순도게르마늄(HPGe) 검출기를 이용하여 드럼의 감마핵종농도를 분석하는 방법과 장치의 개발에 대해 언급하였으며 알파나 베타핵종과 같이 직접 분석이 곤란한 핵종들은 각 폐기물드럼내에 존재하는 Co-60이나 Cs-137과의 상관관계를 미리 예측한 척도인자 (scaling factor)를 이용하여 간접적으로 구하는 방법을 사용하고 있으나 본 논문에서는 드럼으로부터 감마핵종만을 분석하는 방법에 대해서만 언급하였다. 또한 핵종분석시스템의 최적 운전조건을 도출하기 위해 드럼회전테이블의 속도결정 및 모의드럼을 이용한 방사능측정 등을 통해 핵종 농도 분석시의 오차를 30% 이내로 유지할 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.459-461
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• 2022

In this paper, we propose a measurement system for measuring radioactivity detected in an indoor environment. This is to measure and prevent radiation generated in various spaces such as general house, workplace, and research institutes. Multi-radioactivity sensors are used to measure multiple spaces simultaneously. The measured radioactivity data is transmitted to the PC in real time through ZigBee and monitored. Even with a small amount of radioactivity, it is considered that it must be installed in a place where radiation exposure is expected, such as a laboratory or workplace, for prevention from chronic radiation syndrome.

• Journal of Radiation Protection and Research
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• v.37 no.4
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• pp.181-190
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• 2012

Naturally occurring radioactive materials (NORM) in building materials are main sources of external radiation exposure to the general public. The objective of this study was to assess external radiation dose in Korean dwellings due to NORM in concrete walls. Reference room model for dose assessment was made by analyzing room structure and housing scale of Korean dwellings. In addition, dose assessments were made for varying room sizes. Absorbed doses to air and effective dose rates were calculated using radiation transport code MCNPX. Assuming a reference room of $3{\times}4{\times}2.8m^3$, absorbed dose rates in air were 0.80, 0.97, 0.08 nGy $h^{-1}$ per Bq $kg^{-1}$ for uranium series, thorium series, and $^{40}K$, respectively. Effective dose rates were 0.57, 0.69, 0.058 nSv $h^{-1}$ per Bq $kg^{-1}$, respectively. Radiation dose resulting from concrete of ceiling and floor increased with room area while radiation dose from concrete of walls decreased with room area. Therefore, total radiation doses were almost the same for the varying room area from 5 to $30m^2$. Effective dose in Korean dwellings was calculated based on measurement data of NORM concentration in concrete and occupancy fraction of Korean population by location. Annual effective dose was 0.59 mSv assuming that indoor occupancy fraction was 0.89 and concentrations of uranium series, thorium series and $^{40}K$ were 26, 39, 596 Bq $kg^{-1}$, respectively. Finally, annual effective dose in Korean dwellings can be calculated by the following equation: Effective dose=indoor occupancy fraction${\times}8760\;h\;y^{-1}{\times}(0.57C_U+0.69C_{Th}+0.058C_K)$.

• Journal of the Korean Society of Radiology
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• v.8 no.6
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• pp.333-338
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• 2014

The fact is that in addition to an increase in social needs that must be managed systematically unnecessary exposure in the field of medical Recent important that the shield has emerged. However, products that are now in practical use, are not subdivided as compared to various medical radiology. Therefore, in the present study, we tried to present with the help of Monte Carlo simulation the structure of the shielding material that has been optimized. Simulated estimation result, the energy of the mammography for (30 kVp) spectrum, check the shielding rate of 90% or more $30{\mu}mPb$, at 2 mmAl case of shielding material of a single, at design time of 1 mmAl and 0.03 mmPb a double shield structure it is determined that more efficient. Also, check the blocking rate of 90% or more $340{\mu}mPb$, at 30 mmAl energy captured general in (80 kVp) spectra, it is considered that a double shield structure, design 1 mmAl and 0.3 mmPb is useful. These results, be used as basic material for the development of commercialization customized products for dose reduction is expected.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.435-442
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• 2007

The number of thyroid diseases treated with radioiodine(I-131) is increasing steadily. The sharp increase in patients who require high dose radioiodine therapy greatly increased the need for new therapy rooms. Accordingly, interest in radiation exposure is rising as well, and is a major psychological stress factor for the patient and those who come in close contact with the patient. This study aimed to minimize the radiation exposure on discharge. Based on various previous reports, the decision for discharge should be individualized depending on many factors related to the patient's living or working environment. Educating patients repeatedly on the importance of sufficient oral hydration, while the adequate amount was relative to the patient's individual condition, greatly lowered the detected radiation measurement within the same admission period. In some cases, the period of admission could be abbreviated.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.55-61
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• 2020

The various types of radiation-generator devices have been used in animal hospitals, and the safety for radiation workers is becoming important in Korea. This study investigated and analyzed the radiation safety management for diagnostic radiation-generator devices and radiation workers of animal hospital. The number of radiation-generator devices and radiation workers of animal hospital increased from 2,138 to 2,972 and from 2,644 and 5,733 for six years. The number of general X-ray, CT, C-arm, portable and dental X-ray in 2019 were 2,204, 58, 67, 770, and 14. The number of veterinarian, veterinary nurse, veterinary assistant, and others in 2019 were 4,236, 1,080, 404, and 13. The average exposure dose of radiation workers in 2018 were 0.21mSv in surface dose, 0.18mSv in depth doses. This study is expected to be the basic data for the safety management of radiation-generating devices and radiation workers in animal hospital.

• Journal of radiological science and technology
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• v.34 no.3
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• pp.183-188
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• 2011

We studied the optimal location where the radiation dose of radiological technologists is minimally measured. The measured scatter dose has been compared with the distance inverse square law. We measured the primary X-ray with different tube conditions (60, 70, 81 and 90 kVp) and distances (60, 120 and 180 cm). The scatter ray has been measured with various locations (42.5, 52.4 and 62.4 cm for front and back side, 0 to 60 cm with 10 cm interval for left and right side). The results of this study showed that the dose of primary X-ray was attenuated to 20.52 (27.20%), 28.58 (25.20%), 38.82 (26.32%) and 48.20 mR (26.27%) for each tube voltages at 120 cm. In addition, The dose were 7.06 (8.91%), 9.90 (8.73%), 13.64 (9.25%) and 16.60 mR (9.05%) at 180 cm. As for the scatter in front and back side, the attenuated dose were 0.15 mR (23.09%) and 0.15 mR (22.08%) at 120 cm, and 0.07 mR (10.43%) and 0.06 mR (8.83%) at 180 cm. Scatter was decreased in third quadrant. Therefore, it is recommended that radiological technologists should keep long distance from the object.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.101-108
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• 1999

The influence of the relative humidity, the temperature and the velocity of supply air on evaporation rate has been studied with non-boiling forced evaporation system in order to treat very low level radioactive liquid wastes produced from the decontamination and decommissioning activities. Experimental data on the evaporation rate have been obtained with the divers variables and experimental equation of air velocity was also obtained by the correlation of those data. The decontamination factor of this system was also obtained by the experimental data from a simulated liquid waste containing Cs-137 radio isotope ; $DF=10^4$. Since the commercial system will be operated for the treatment of the very low level radioactive liquid waste produced from decontamination & decommissioning of TRIGA Mark-II&III research reactor, the environmental assessment has been conducted to improve the operational safety. Exposure dose rate for an individual member of general public was assessed, and it showed that it was very lower than individual dose limits. The release of radioactivity of radioisotope material (Cs-137) to the environment was assessed, and result showed that it was $4.637{\times}10^{-14}\;{\mu}Ci/cc$.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.371-376
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• 2017

Since in case of children, they are sensitive to the radiation compared to the adult and the potential exposure damage lasts longer, the exposure dose should be managed better than for the adult. Therefore, this study was conducted to observe the change in the chest x-ray image by the use of grid, which eliminates the scattering rays but increases the exposure dose during the child chest x-ray examination. As a research method, SNR, CNR and V. Vuichi were measured at 100 cm and 180 cm with the grid varying the kVp to 70, 90 and 110. In addition, SNR, CNR and V. Vuichi were measured fixing 100 cm and 180cm without grid and varying the dose to 6, 8 and 10 mAs. In the results of measuring them by fixing kVp, SNR, VNR and V. Vuichi were represented high when FID is 100cm. And in the results of meaduring them varying mAs, SNR, VNR and V. Vuichi were represented high when FID is 100cm. Currently in our country, the chest x-ray examination is performed at 180 cm. However, as the image is measured high when FID is 100 cm, in case of child, FID is deemed to be 100 cm.