Has anyone dealt with the N-13/O-15 generation from accelerators? I'm trying to determine their ALIs. Also, how does the EPA's "Concentration Levels for Environmental Compliance" (from the COMPLY code manual) relate to the above? Thanks is advance for replies. Tom O'Brien RSO AFRRI Bethesda, MD <OBRIEN@vax.afrri.usuhs.mil> 301-295-1285