An in situ gross alpha monitoring technique for delineating fugitive mill tailings

In situ gross alpha counting of soils is an effective technique for measuring uranium mill tailings contamination. In a field test, five minute gross alpha measurements were found to be capable of discerning tailings contamination at a level of 1.5 Bq (total alpha) per gramme of soil (41 pCi/g) in the presence of natural soil radioactivity. This corresponds to 0.28 Bq/g (7.6 pCi/g) for 226Ra in tailings (with an assumption of secular equilibrium less 12% of radon and progeny). The equipment is inexpensive, rugged, and truly portable. (author)