Gross alpha activity as an estimator of radium-226 activity in soils and tailings at an inactive uranium mill tailings site

Gross alpha activity in surface tailings and surface soils from one inactive uranium mill site has been shown to be an accurate estimator of 226Ra activity. An exponential regression, 226Ra = 387(e/sup 0.00166α/ - 1), where 226Ra activity is in picoCuries per gram and gross alpha activity is in counts per minute per sample, gave a good fit for samples ranging in gross alpha activity from 3 to 1082 cpm/sample. A linear regression, 226Ra = 1.05 α + 1.78, has been calculated, which shows gross alpha activity to be an excellent estimator of 226Ra activity in soils contaminated with tailings. The percentage of gross alpha activity attributable to 226Ra activity has been calculated to be 7.2, 17.6, 18.3, and 17.0 for uncontaminated soils, contaminated soils, tailings, and the total set of samples, respectively