|
KMID : 0364920120370040181
|
|
Journal of Radiation Protection and Research
2012 Volume.37 No. 4 p.181 ~ p.190
|
|
|
External Exposure Due to Natural Radionuclides in Building Materials in Korean Dwellings
|
|
Cho Yoon-Hae
Kim Chang-Jong
Yun Ju-Yong
Cho Dae-Hyung
Kim Kwang-Pyo
|
|
|
Abstract
|
|
|
|
aturally 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 3×4×2.8 m3, 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 40K, 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 30 m2. 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 40K 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×8760 h y-1×(0.57CU+0.69CTh+0.058CK).
|
|
|
KEYWORD
|
|
|
Building material, Naturally Occurring Radioactive Material, NORM, External exposure
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|