Studies of an improved polonium-210 analytical procedure and the distribution and transport of uranium and its alpha emitting daughters using nuclear emulsions. Final report

Abundant evidence for the recent separation, transport and redeposition of Ra-226 has been obtained. On the basis of both alpha star populations and possibly the presence of numerous barite grains containing Ra-226, unsupported Ra-226b appears to be more mobile than Rn-222 and is widely distributed. These observations confirm tentative conclusions made in the preliminary study. Experiments undertaken to improve the precision of the Po-210 chemical leaching procedure do appear to have been successful. The increase in the number of residue washes has improved the reproducibility of the measurements. Uniform stirring rates during the four hour auto-plating step have been found to be important. Neither the Po-210 drill core data reported earlier in the preliminary study nor the results of the nuclear emulsion studies of the same cores reported in this paper provide any supporting evidence for the predicted Po-210 concentration gradient produced by the decay of mobile, unsupported Rn-222 either in transit to the surface or even in transit over short distances from pronounced Po-210 highs. The Po-210 analyses and microscopic studies suggest that observed Rn-222 and Po-210 surface anomalies may be associated with widely dispersed, very low concentrations of Ra-226 or its longer lived parents including uranium. These members of the uranium decay chain may be distributed around the ore at depth as halos or as weak zones of uranium mineralization. Should this tentative conclusion be supported by more comprehensive field and laboratory investigations, the exploration geologist may find that Ra-226/Po-210 ca be used in the field as an effective radiochemical technique in the search for uranium