건축자재에 발생되는 라돈/토론 농도측정

The annual average dose of radiation exposure to Korean people is 3.6 mSv and 50% of this amount is known to be by the exposure to radon gas. Such radiation exposure to radon has been known to be caused by the inflow of radon gas mainly through the cracks in buildings but the recently reported cause of radiation exposure to radon inside buildings even such as high-rise apartments is the radiation from construction materials. In this study, in order to investigate the current situation through measuring the radon radiation from the construction materials on sale through construction material shops in Gwangju Metropolitan, two acrylic boxes in 5T thickness and 216L volume were produced using a movable successive radon monitoring device RTM 1688-2 in silicon surface barrier type which could measure the concentration of radon and thoron simultaneously. After putting the construction materials bought in construction material shops in Gwangju to the boxes and sealing them, radon concentration was measured and recorded for 10 hours from the 91st hour to the 100th hour from 3.8 days which would be required to reach 50% of Rn-222 concentration against Ra-226 concentration. In the radon concentration radiated from the sample materials, plaster-tex (K) showed the highest value of 39.6 Bq/kg and followed by plaster-tex (L) of 23.6 Bq/kg and plaster-tex (B) of 17.4 Bq/kg. The result of the measurement showed that an effective reduction of radiation had been achieved through the Korean authority``s continuous regulation and management on the usage of phospho-gypsum as plaster-tex and the mixture usage of fly-ash cement. From this result, the construction materials on sale in Gwangju Metropolitan could be deemed to be somewhat safe but the radon radiation amount should be traced and observed continuously because there could be different amount of radiation according to the difference of mixture depending on the manufacturing period of construction materials in the aspect of their characteristic.