The Use of Natural Radionuclides to Predict the Behavior of Radwaste Radionuclides In Far-Field Aquifers

Abstract

ABSTRACTIn appropriate aquifers the natural radionuclides of the U and Th decay series are important sources of information about the behavior of radwaste radionuclides in far-field aquifers. The Wolfcamp Carbonate, Pennsylvanian Carbonate and Granite Wash aquifers in the Palo Duro Basin of the Texas Panhandle are prime examples of such aquifers. Sampling and analysis for key radionuclides in the ground waters of these aquifers are quite feasible and have been accomplished. Key early results are: (1) Ra does not appear to be retarded by sorption, (2) Th appears to be strongly sorbed, (3) kinetics seem to be different on time scales of days to months than on ones of hundreds of thousands of years, and (4) U and Th behave similarily when the time scales (half-lives) are similar, leading to the suggestion that uranium is in the +4 valence state in these aquifers.