• Journal of the Korean Society of Radiology
• /
• v.9 no.6
• /
• pp.421-424
• /
• 2015

In this study, To subject the constructed at N-kindergarten in G-city, the position is closed window and opened window was measured using a measuring instrument for radon. The measured results indicate that the measurement was carried out in concentrations of radon gas measured at N-kindergarten is low than United States in the radon concentration in air public 4pCi called radon gas baseline maximum allowable concentrations. As a result, radon exposure is not a problem, but when the accumulation radon gas in the lungs, get damaged same lung cancer. Be defensive of kindergarten windows open for ventilation and dust removal be possible to reduce the exposure.

• Journal of radiological science and technology
• /
• v.46 no.2
• /
• pp.141-149
• /
• 2023

The Korea Institute of Radiological and Medical Sciences plans to produce ²²⁵Ac, a therapeutic radio-pharmaceutical for precision oncology, such as prostate cancer. Radon, a radioactive gas, is generated by radium, the target material for producing ²²⁵Ac. The radon concentration is expected to be about 2000 Bq·m^-3. High-concentration radon-generating facilities must meet radioactive isotope emission standards by lowering the radon concentration. However, most existing studies concerning radon removal using activated carbon filters measured radon levels at concentrations lower than 1000 Bq·m^-3. This study measured ²²²Rn removal of coconut-based activated carbon filter under a high radon concentration of about 2000 Bq·m^-3. The ²²²Rn removal efficiency of activated carbon impregnated with triethylenediamine was also measured. As a result, the ²²²Rn removal amount of the activated carbon filter showed sufficient removal efficiency in a ²²²Rn concentration environment of about 2000 Bq·m^-3. In addition, despite an expectation of low radon reduction efficiency of Triethylenediamine-impregnated activated carbon, it was difficult to confirm a significant difference in the results. Therefore, it is considered that activated carbon can be used as a radioisotope exhaust filter regardless of whether or not Triethylenediamine is impregnated. The results of this study are expected to be used as primary data when building an air purification system for radiation safety management in facilities with radon concentrations of about 2000 Bq·m^-3.

• Nuclear Engineering and Technology
• /
• v.51 no.8
• /
• pp.2013-2017
• /
• 2019

The radon concentrations in soil air were measured before and after a rainfall. ²²⁶Ra concentration, porosity, moisture content and temperature in soil were measured at Kyungpook National University in Daegu. As the results of measurement and analysis, the arithmetic mean of measured ²²²Rn concentration increased from 12100 ± 500 Bq/㎥ to 16200 ± 600 Bq/㎥ after the rainfall. And the measured ²²⁶Ra concentration was 61.4 ± 5.7 Bq/kg and the measured porosity was 0.5 in soil. The estimated values of ²²⁶Ra concentration and porosity using diffusion model of ²²²Rn in soil were 60.3 Bq/kg and 0.509, respectively. The estimated values were similar to the measured values. ²²²Rn concentration in soil increased with depth and moisture content. The estimations were obtained through fitting based on the diffusion model of ²²²Rn using the measurement values. The measured depth profiles of ²²²Rn were similar to the calculated depth profiles of ²²²Rn in soil. We hope that the results of this study will be useful for environmental radiation analysis.

• Journal of the Korean Society of Radiology
• /
• v.9 no.4
• /
• pp.257-261
• /
• 2015

Radon is produced after the Uranium-238 and thorium-232 undergone radioactive decay process is a colorless, odorless inert gas is stored in a basement or an enclosed space. Building materials are made by a rock or soil materials. Form of radon gas is introduced into the lungs through the respiratory tract and deposited in the lungs or bronchial Daughter nuclides radon causes lung cancer. In this study, To subject the Constructed Apartment in Gwangju Gwangsan-Gu, the position is closed window and opened window was measured using a measuring instrument for radon. The measured results indicate that the measurement was carried out in concentrations of radon gas measured at Newly Constructed Apartment is low than United states in the radon concentration in air public 4 pCi called radon gas baseline maximum allowable concentrations. The exposure caused by radon concentration of new construction apartment when on the measurement results is expected to be insignificant. However, when radon gas like this is that it accumulates in the body and lungs get damaged due to exposure, such as lung cancer often open the windows to reduce the radon concentration measurements, such as in radiation protection aspects to the ventilation to reduce exposure it is considered necessary.

• Particle and aerosol research
• /
• v.13 no.2
• /
• pp.87-95
• /
• 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.

• Economic and Environmental Geology
• /
• v.31 no.5
• /
• pp.415-424
• /
• 1998

In order to investigate soil-gas $^{222}Rn$ concentrations, Kwanak Campus (Seoul National University), Boeun (Choong-buk) and Gapyung (Kyonggi) areas were selected and classified depending on their base rock types. Radon risk indices of these study areas decrease in the order of Gapyung>Kwanak Campus>Boeun areas, and in the order of rock type as banded gneiss>granite gneiss>granite>black slate-shale>mica schist>shale-lirnestone>phyllite-schist. Radon emanating trends with water content and grain size of soils were assessed by modified Morse 3 min. method. Radon emanation increases with the increase of water content in soils which is lower than 6~16 wt.%, and decreases in the range of higher than 6-16 wt. %. It shows that Rn emanation increases with the decrease of soil grain size. Radioactivity analysis of radionuclides of 238U series in some soil samples shows that radioactive disequilibrium state between $^{226}Ra$ and $^{238}U$ exists owing to different geochemical behavior of each radionuclide, and, it is necessary to carry out radioactive isotope geochemical approach for soil-gas $^{222}Rn$ study.

• Journal of Environmental Science International
• /
• v.15 no.4
• /
• pp.311-317
• /
• 2006

The purpose of this study was to investigate Rn concentration and annual radiation exposure level in the basement and first floor. The Rn Cup monitors were placed in different environments such as shopping stage, office building, Apartment, Hospital, house in Seoul from Match 1996 to April 1997 and CR-39 films were collected every two months. The mean radon concentration in the basement of house($88.6\;Bq/m^3$) showed the highest level among the areas, while radon concentration on the first floor of house($50.5\;Bq/m^3$) showed the higher than other areas. The annual radiation exposure dose that person on the floor / in the basement of differential place in the seoul can be exposed during living was estimated from 24.11 to 87.64 mRem/yr. This radiation dose is significantly lower than 130mRem maximum radiation dosage from the radon nuclide prescribed by the ICRP, with respect to the overall average exposure of the working adult. this study indicated that possible radon sources on the first floor / in the basement areas are radon intrusion from soil gas, construction materials, or ground water leaking. Further study is needed to quantitatively assess major contributions of radon-222 and health effect to radon exposure.

• Journal of Radiation Protection and Research
• /
• v.16 no.2
• /
• pp.41-54
• /
• 1991

This paper aimed to analyse dose sensitivity to the controllable parameters of indoor radon $(^{222}Rn)$ and its decay products (Rn-D) by applying the input~output linear system theory. Physical behaviors of $^{222}Rn\;&\;Rn-D$ were analyzed in terms of $(^{222}Rn)$ gas -generation, -migation and -infiltration to indoor environments, and the performance output-function, i. e. mean dose equivalent to Tracho-Bronchial (TB) lung region, was assessed to the following extented ranges of the controllable paramenters; a) the ventilation rate $constant({\lambda}_v)\;:\;0{\sim}50[h^{-l}].\;b)$ the attachment rate $constant({\lambda}_a)\;:\;0{\sim}500[h^{-l}].\;c)$ the unattached-deposition rate constant (${\lambda}^u_d)\;:\;0-50[h-l]$. A linear input-output model was reconstructed from the original models in literatures, as follows, which was modified into the matrices consisting of 111 nodal equations; a) indoor $^{222}Rn\;&\;Rn-D$ Behaviour; Jacobi-Porstendoerfer-Bruno model.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.308-311
• /
• 2005

[ $^{222}Rn\;and\;^{226}Ra$ ] in groundwater were determined simultaneously using a gamma-spectroscopy. A nitrogen flushing equipment has been used for elimination and stabilization of high and unstable background activity due to the radon and its progenies in counting shield and room. The aim of present work was to control the background activity for simultaneous measurement of radium$(^{226}Ra)$ and radon$(^{222}Rn)$ in groundwater using a gamma-spectrometry. Background activity was about 1.0dps and the standard deviation was about 50%, The background activity could be minimized using nitrogen flushing equipment in the range of 0.1 to 0.5 and the RSD was about 5% at the experimental condition. The detection limit of $^{222}Rn\;and\;^{226}Ra$ in groundwater was 0.5dps/L in the background control method. In most groundwater used in the work, radon activity was more than the detection limit. However, radium activity in some groundwater was less than the detection limit. If the low level radium in groundwater must be measured, preconcentration process such as concentration should be performed before measuring the groundwater.

• Journal of Korean Society on Water Environment
• /
• v.23 no.2
• /
• pp.201-205
• /
• 2007

This paper reports the amount of $^{222}Rn$ and $^{238}U$ in 18 sites of ground water and 30 sites of surface water. The instrument used to count $^{222}Rn$ activity was the liquid scintillation counter (LSC) which could resolute ${\alpha}$ and ${\beta}$ radiations. And $^{238}U$ was analyzed by the inductively coupled plasma (ICP). Radon and Uranium were not detected in raw and treated water which were sampled in a water treatment plant. However, radon ($^{222}Rn$) was high concentration in ground water from Jeon-la, Gang-won. So was uranium ($^{238}U$) in case of ground water from Gang-won, Choong-chung. Radon ($^{222}Rn$) activities were detected less than 15 pCi/L at 5 sampling points, 15~300 pCi/L at 7 sampling points, 300~4000 pCi/L at 6 sampling points. However, Radon ($^{222}Rn$) activities of all ground water samples were less than 4,000 pCi/L, which was bellow American Alternative Maximum Contamination Level (AMCL). Uranium ($^{238}U$) concentrations were less than $0.1{\mu}g/L$ at 5 sampling points, from $0.1{\mu}g/L$ to $20{\mu}g/L$ at 13 sampling points. Uranium was not detected in about 30% of the whole samples, but the concentration ranged from relatively low to high concentrations depending on the sampling point. The minimum detectable activity (MDA) of radon was 15 pCi/L. and the detection limit of uranium was $0.1{\mu}g/L$.