Small Annular Source
This annular steel source is 1" long and 3/8" in diameter. The central channel is approximately 1/8" in diameter. It is non-magnetic. Each end is welded. Presumably one well was performed in the shop prior to the source loading, and the other weld was performed inside a hot cell. Unfortunately, there are no markings of any kind on it. While it was not fabricated at Oak Ridge National Laboratory, it might have come from there. It is likely that it was used to irradiate fluids (e.g., blood) passing through the central channel. The source material would have been Cs-137, maybe a curie or less.
Karl Haff, personal communication. At different times, Haff headed up ORNL's Source Safety Testing Program and their Radiochemical Processing Program.