Nitric acid leaching of radium and other significant radionuclides from uranium ores and tailings

Nitric acid leaching of representative uranium ores and mill tailings from the western U.S. mining districts removes up to 98% of the /sup 226/Ra and /sup 230/Th, yielding a residue containing 17 to 60 pCi of radium per gram. At best, this is an order of magnitude greater than that in surrounding soils, but about the same level as a standard proposed for building materials in the United Kingdom. Data are also presented on the water penetration and leaching of tailings, the solubility of BaSO/sub 4/, and radon emanation coefficients of ores, tailings, and nitric acid-leached residues.