Assessment of radon concentrations and exposure doses in dwellings surrounding a high capacity gas turbine power station using passive measurements and dispersion modeling.

A continuous passive measurement of indoor and outdoor radon R222n, concentration is carried out in the nearby residential areas surrounding a high capacity gas-fired power station. The mean value for indoor measurements was 26.5 ±â€¯1.75 Bq/m3 that is below the worldwide indoor mean of 40 Bq/m3 and for outdoor was 39.4 ±â€¯4.04 Bq/m3 which is higher than the worldwide average outdoor radon concentration of 10 Bq/m3. The annual estimated effective doses were found to vary from 0.54 to 1.05 mSv/y with an average value of 0.67 ±â€¯0.04 mSv/y for indoor dose and from 0.23 to 0.57 mSv/y with an average value of 0.37 ±â€¯0.03 mSv/y for outdoor dose with an overall mean annual effective dose of 1.03 mSv/y. Furthermore, the measured and modeled radon excess levels due to plant operation, both, show that the effect of power plant emission on atmospheric radon levels in the surrounding region is not significant.

RADIOACTIVITY MEASUREMENT AND RADIOLOGICAL HAZARD ASSESSMENT OF THE COMMONLY USED GRANITE AND MARBLE IN JORDAN.

Natural radioactivity of common commercial marble and granite types used in Jordanian dwellings are measured using high-resolution gamma spectrometry. The activity concentrations of 226Ra, 232Th and 40K ranged from 8.57 ± 1.55 to 152.07 ± 3.26 Bq kg-1, 6.83 ± 1.25 to 365.43 ± 4.84 Bq kg-1 and 121.25 ± 9.10 to 1604.90 ± 31.28 Bq kg-1 in granite and from 0.53 ± 0.12 to 18.61 ± 1.60 Bq kg-1, 0.51 ± 0.19 to 4.87 ± 2.13 Bq kg-1 and 3.21 ± 0.96 to 58.09 ± 6.40 Bq kg-1 in marble, respectively. Various radiological hazard indices like gamma index, internal and external hazard indices and annual effective dose equivalent were calculated and compared with the international limits. Our results show that some granite types may pose a radiation hazard.