Radsafers, Does you have any info on the amount of Pu-238 in the various SNAP generators? Also, as I recall something burned on reentry in the 1960's, resulting in a Pu-238 background. Any details on that? Please reply directly to wattsjr@ornl.gov to minimize network clutter. James R. Watts Bldg. 2008, MS6041 Oak Ridge National Lab phone 423-574-7464 email: wattsjr@ornl.gov