• Journal of Radiation Protection and Research
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• 제4권1호
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• pp.5-13
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• 1979

공기시료채칩 종료후 공기여과지에 채집된 시료중 방사능을 일정한 시간구간을 두어 계측함으로써 얻은 붕괴곡선을 이론적 방법에 의하여 분석할 수 있는 간단한 방법을 개발하였으며, 이 방법을 이용하여 라돈 붕괴생성물 각각의 공기중 방사능 농도를 결정하였다. 라돈 붕괴생성물 각 핵종의 방사능 농도는 알파붕괴, 시료채집시간, 그리고 수치계수의 함수로 표시된 방정식으로 부터 얻었다. 그리고 대기중 라돈 붕괴생성물 개개의 방사평형상태도 또한 조사하였다. TRIGA Mark-III 원자로실내에서 채집한 공기시료는 상당히 비평형상태에 있었다. 라돈 붕괴생성물들 간의 방사성 불평형의 정도는 공기와류조건과 관련된 공기시료 채집시간에 따라 상당히 달라지는 것같았다. 본 연구 결과에서 얻은 자료는 인체 내부방사선 피폭선량평가와 기체 방사성 물질 방출감시기 교정에 유용한 기초자료가될 것이 확실하다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.113-114
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• 2017

Recently, Subway workers have died from lung cancer. According to the Epidemiological Survey of the Welfare Corporation Institute of Pulmonary Disease of the Welfare Corporation, the family members applied for industrial accidents. The radon concentration in the subway work area was found to exceed 10 times the recommended standard value of 148 becquerels (Bq/㎥) in domestic multipurpose facilities. In addition, as a result of the national indoor radon concentration survey conducted by the Ministry of Environment in 2010 and 2013, housing was found to be over 100 becquerels (Bq/㎥) in 41% of the surveyed subjects. In addition, it was found that in 2012, 16.3% of villages exceeded the radon standard value in the survey on natural radioactive materials containing groundwater.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.139-146
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• 2001

Modern people stay at indoor places about 90% of a day. Radon-222 is a gas produced radioactive decay of the element radium. And, radon is one of the major indoor air pollutants moves into the underground space through various routes and is considered to cause lung c hurting the lung tissues, In this study, we measured the subway radon level at 9 stations o According to test results, we can figure out the concentration of radon by lines, times, and m points. So, it was found that ventilation conditions are the most important factors in the su quality. Finally, we suggested effective and economic management methods of air pollution subway.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1498-1507
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• 2003

A SMPS(scanning mobility particle sizer) system measures the number size distribution of particles using electrical mobility detection technique. An aerosol charge neutralizer, which is a component of the SMPS, is a bipolar charger using a radioactive source to apply an equilibrium charge distribution to aerosols of unknown charge distribution. However, the performance of aerosol charge neutralizers is not well known, especially for highly charged particles. In this study, the effect of the particle charging characteristics of two aerosol charge neutralizers on the measurement using a SMPS system was experimentally investigated for highly charged polydisperse particles. One has radioactive source of $^{85}$ Kr (beta source, 2 mCi) and the other has $^{210}$ Po (alpha source, 0.5 mCi). The air flow rate passing through each aerosol charge neutralizer was changed from 0.3 to 3.0 L/min. The results show that the non-equilibrium character in particle charge distribution appears as the air flow rate increases although the particle number concentration is relatively low in the range of 1.5∼2x10$^{6}$ particles/㎤. The low neutralizing efficiency of the $^{85}$ Kr aerosol charge neutralizer for highly charged particles can cause to bring an artifact in the measurement using a SMPS system. However, the performance of the $^{210}$ Po aerosol charge neutralizer is insensitive to the air flow rate.

• Nuclear Engineering and Technology
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• 제17권4호
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• pp.267-278
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• 1985

원자력발전소로부터 배출되는 방사성물질에 의한 피폭선량을 규제하는데 있어 몇 가지 종류들의 방식들이 적용되어 왔다. ICRP에 의해 권고된 일차 선량 당량 제한치가 가장 근본적인 것이다. 일차 제한치가 직접 적용될 수 없을 때 외부 피폭의 경우 선량당량 지표가 내부피폭의 경우 최대허용농도, 연섭취 제한치 흑은 유도대기 농도 및 최대 신체 부하량 등이 이용되어 왔다. 그러나 이 값들은 실제 배출량을 제어하는 견지에서 바로 사용할 수 없어 유도방출 기준치를 구하게 된다. 본 연구에선 월성 원자력발전소에 대해 고려되는 특정환경들 사이의 전달속도가 시간에 독립적인, 장기성 농축인자 방식으로 방출속도의 유도 제한치를 구하였다.

• Nuclear Engineering and Technology
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• 제32권4호
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• pp.350-360
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• 2000

In Korea, the dose limits are reduced and are set at the ICRP-60 iimits. However, derived limits tabulated as MPC in air and water are still specified in Notice No.98-12. There are some discrepancies between the primary dose limits and MPCs in air and water. Therefore, in order to accept ICRP-60 recommendations fully, derived limits such as ALI, DAC, ECL for radiological protection against ionizing radiation based on ICRP-60 recommendations were calculated using modified methods of those of 10 CFR part 20, dose limits and committed effective dose coefficients of the Basic Safety Standards of the IAEA. The derived limits in this study were also compared with those prescribed in 10 CFR part 20 as well as MPCs of Notice No. 98-12 in order to analyze the impact of implementing derived limits on nuclear facilities. ECLs in air and water for the control of radioactive discharge into the environment in this study are shown to have lower values (i.e. more conservative), for most part, than those in Notice No. 98-12. Especially, for uranium elements, ECLs in water are approximately a magnitude in the order of two lower than those in Notice No.98-12.

• 한국입자에어로졸학회지
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• 제13권2호
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• pp.87-95
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• 2017

Radon ($Rn^{222}$) is a radioactive gas and is found at high concentrations underground. Investigations were done in many years specifically on public transportations such as in the subway stations, concourses and platforms for these are located underground areas. This study correlates the $Rn^{222}$ concentrations with the Particulate Matter (PM) concentration for the gas could be attached or trapped inside these particles. It was done on the opening subway tunnel of Miasageori Station going to Mia Station (Line 4) last August 2016. Based on the result, the $Rn^{222}$ were more influenced on the mass ratio (%) of PM present in the air instead of its mass concentration (${\mu}g/m^3$). As the $PM_{10}$ mass ratio increases ($42.32{\pm}1.03%$) during morning rush-hours, radon starts to increase up to $0.97{\pm}0.03pCi/L$. But during the afternoon $Rn^{222}$ concentrations decreased while the composition were stable at $22.96{\pm}3.0%$, $39.04{\pm}0.6%$ and $38.01{\pm}0.3%$ in $PM_1$, $PM_{2.5}$ and $PM_{10}$ respectively. It was then assumed that it could be the composition of the morning hours of the station were influencing the concentration of the radon.

• Journal of Radiation Protection and Research
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• 제46권2호
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• pp.58-65
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• 2021

Background: The evaluation of skyshine distribution, release of airborne radioactive nuclides, and soil activation and groundwater migration were required for radiological assessment of the impact on the environment surrounding In-Flight (IF)-system facility of the RAON (Rare isotope Accelerator complex for ON-line experiment) accelerator complex. Materials and Methods: Monte Carlo simulation by MCNPX code was used for evaluation of skyshine and activation analysis for air and soil. The concentration model was applied in the estimation of the groundwater migration of radionuclides in soil. Results and Discussion: The skyshine dose rates at 1 km from the facility were evaluated as 1.62 × 10^-3 μSv·hr^-1. The annual releases of ³H and ¹⁴C were calculated as 9.62 × 10^-5 mg and 1.19 × 10^-1 mg, respectively. The concentrations of ³H and ²²Na in drinking water were estimated as 1.22 × 10^-1 Bq·cm^-3 and 8.25 × 10^-3 Bq·cm^-3, respectively. Conclusion: Radiological assessment of environmental impact on the IF-facility of RAON was performed through evaluation of skyshine dose distribution, evaluation of annual emission of long-lived radionuclides in the air and estimation of soil activation and groundwater migration of radionuclides. As a result, much lower exposure than the limit value for the public, 1 mSv·yr^-1, is expected during operation of the IF-facility.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.172-181
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• 2005

국내 원전에서 공기 중 삼중수소 농도를 평가하기 위해 사용하는 삼중수소 버블러의 포집효율에 대하여 고찰하였다. 수증기 형태인 공기 중 삼중수소는 기포가 물을 통과하는 동안 평형농도에 도달하게 된다. 많은 양의 기체시료를 통과시킬 경우 포집수의 삼중수소 농도가 높아지고 포집수가 감소하거나 증가하는 현상이 발생하여 포집효율에 영향을 미치게 된다. 이러한 영향을 고려한 포집수의 예측농도는 실측값과 잘 맞았다. 통상적인 방식과 같이 초기 포집수량을 이용하여 삼중 수소 포집량을 평가할 경우 기체시료의 상대습도가 0.5보다 높으면 포집효율은 1보다 낮아지고 상대습도가 0.5보다 낮으면 포집효율은 1보다 높아진다. 상대습도가 0.5가 아니더라도 $\frac{포화수증기량\times기체통과량}{포집수량}$을 작게 하면 포집효율을 1에 가깝게 유지할 수 있다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2001년도 추계학술대회 논문집
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• pp.79-79
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• 2001

최근 서울의 각 지하철역에서의 라돈농도 측정결과가 각 일간지 및 방송에 보도되면서 서울시의회업무 보고 및 국정감사에서도 중요한 이슈의 하나로 부각되었다. 라돈에 관한 미환경청(USEPA)의 규제치(action level)는 4pCi/L이며 이때의 방사평형인자는 0.5로 되어있다. 서울시에서는 2000년도에 195개소 즉 175개역사와 20개소의 환승통로에 대한 라돈농도에 대한 장단기농도 측정과 1999년도에는 라돈자핵종을 분석하여 이를 바탕으로 라돈방사평형인자를 구한바 있다. (중략)