Can anyone point me to some references on concentrations of uranium, thorium, and daughter radionuclides present in motor oil? I realize that the concentrations will vary widely depending on th source of the crude and the processing; at the moment I am just looking for some ballpark numbers. thanks, Kevin Meyer K25 Nondestructive Assay Facility Oak Ridge, TN kqv@ornl.gov (423) 241-6714