I recently acquired a 39 gram sample of U-238 metal. I ran a gamma spectrum on the sample and found a major peak around 97 keV. I couldn't find any documents that mentioned this peak for U-238, but it is very prominent. I ran a gamma ray spectrum on a 5 gram Uranium Oxide sample and it also exhibits the gamma ray peak around 97 keV. Does anyone know how this gamma-ray peak is being generated? I've looked at the decay chain for U-238, but could not find any references to a 97 keV peak.