Abstract: Radiologic Considerations in Development of Geothermal Resources in Western United States

R. F. Kaufmann, M. F. O'Connell

Recent sampling of selected hot springs and geothermal wells in eight western states for radium, dissolved radon, uranium, and thorium provides a preliminary estimate of the associated radioactivity and potential health effects related to geothermal resource development. Radiochemical data from a variety of geothermal systems and geologic terrains are correlated with reservoir conditions inferred from heat-flow measurements and several geochemical thermometers. Radioactive constituents in the geothermal waters sampled commonly exceed accepted levels for potable water by an order of magnitude or more. Radon gas, in particular, is present in concentrations exceeding 3,000 pCi/l in areas of active Tertiary volcanism and crustal extension. A simplified technique developed for in-field sampling of dissolved radon is described.

The data suggest that analysis of geothermal waters should include the common radioactive constituents, regardless of their importance as an exploration tool or as marketable by-products. Concentrations of radium and radon in the geothermal areas studied are of such magnitude that utilization of the resources may require specific programs to maintain acceptable radiologic-dose commitments to the labor force and the local populace.

AAPG Search and Discovery Article #90979©1975 AAPG – SEPM Rocky Mountain Sections Annual Meeting, Albuquerque, New Mexico