Radon emanating capacity determination for soils of South Karelia

An experimental evaluation of the coefficient of emanation of loamy and sandy soils in southern Karelia was carried out by hermetic sealing of the emanating stratum and the emanation method in laboratory conditions. The coefficients of emanation method in laboratory conditions. The coefficients of emanation obtained from the data given by laboratory analysis of samples that had not been mechanically processed were 40-50% for loamy soils and about 20% for sandy soils. These figures agree well with the results of the measurements by the stratum sealing method. The experimental data presented show that in the case of loamy soils in southern Karelia, high coefficients of radon emanation may be observed. The related errors in the gamma-spectrometric measurements of radium concentrations are as high as 50% of the measured value, and this error exceeds all others. Consequently, an accuracy of the order of 10-20%, which is needed for the solution of various scientific and practical tasks, can be obtained only if corrections are made for emanation. The conclusions arrived at confirm earlier published data according to which the radon emanation coefficient for soils in the Soviet Union is fairly high and averages about 40%. (E.G.)