Atmospheric deposition patterns of 210Pb and 7 Be in Cienfuegos, Cuba

The radiometric composition of bulk deposition samples, collected monthly for one year, February 2010 until January 2011, at a site located in Cienfuegos (22 030 N, 80 290 W) (Cuba), are analysed in this paper. Measurement of 7 Be and 210Pb activity concentrations were carried out in 12 bulk deposition samples. The atmospheric deposition fluxes of 7 Be and 210Pb are in the range of 13.2e132 and 1.24e8.29 Bq m2 , and their mean values are: 56.6 and 3.97 Bq m2 , respectively. The time variations of the different radionuclide have been discussed in relation with meteorological factors and the mean values have been compared to those published in recent literature from other sites located at different latitudes. The annual average flux of 210Pb and 7 Be were 47 and 700 Bq m2 y1 , respectively. Observed seasonal variations of deposition data are explained in terms of different environmental features. The atmospheric deposition fluxes of 7 Be and 210Pb were moderately well correlated with precipitation and well correlated with one another. The 210Pb/7 Be ratios in the monthly depositions samples varied in the range of 0.05 e0.10 and showed a strong correlation with the number of rainy day

Application of the Monte Carlo efficiency transfer method to an HPGe detector with the purpose of environmental samples measurement

Monte Carlo efficiency transfer method was used to determine the full energy peak efficiency of a coaxial n-type HPGe detector. The efficiencies calibration curves for three Certificate Reference Materials were determined by efficiency transfer using a 152Eu reference source. The efficiency values obtained after efficiency transfer were used to calculate the activity concentration of the radionuclides detected in the three materials, which were measured in a low-background gamma spectrometry system. Reported and calculated activity concentration show a good agreement with mean deviations of 5%, which is satisfactory for environmental samples measurement

Naturally occurring radioactive materials (NORM) in ashes from a fuel-oil power plant in Cienfuegos, Cuba, and the associated radiation hazards

The radioactivity of NORM was measured in ashes collected from a fuel-oil power plant in Cienfuegos, Cuba, using an HPGe gamma-ray spectrometer. The (226)Ra, (210)Pb, (40)K, (232)Th and (238)U activity concentrations reached 240, 77, 59, 70 and 15 Bq kg(-1), respectively. The potential radiological hazard of these residuals was assessed. The radium equivalent activities of the samples varied from 54 to 345 Bq kg(-1). The gamma index was calculated to be lower than that of the reference values, and the gamma absorbed dose rate was higher than the average reported for the earth's crust; however, the assessed annual effective dose was slightly lower than the annual effective dose limit for public, i.e. 1 mSv. Therefore, these bottom ashes were not dramatically enriched with radionuclides and may be used as an additive for building materials without restrictions from a radiological protection point of view