Can anyone provide a reference for determining the isotopic distribution for enriched uranium? Specifically, given a sample of 93% enriched uranium, how can I determine the composition of the other 7%? Is it appropriate to assume negligible U-238 so that the remainder would be U-234? Thanks for your help. Mike Lewandowski Health Physicist 3M Company MALewandowski@MMM.com (612) 737-4452