What sources are tracked by the NSTS?
Within the scope of the NSTS, the sources of interest are a subset of sealed sources, known as “nationally tracked sources.” These sources contain quantities of radioactive material that are equal to or greater than the Category 2 Nationally Tracked Source Thresholds set forth in Appendix E to Title 10, Part 20, of the Code of Federal Regulations (10 CFR Part 20), “Standards for Protection Against Radiation.” For example, nationally tracked sources include the individual sources in an irradiator, the sources used in a gamma knife, most radiography sources, some well-logging sources, and any other sources that meet the criteria for tracking. Nationally tracked sources do not include materials that are encapsulated solely for disposal, or any type of nuclear material contained in a fuel assembly, subassembly, fuel rod, or fuel pellet.
