Radioactive Sealed Source

A radioactive material that is permanently sealed in a capsule or closely bonded to a non-radioactive substrate designed to prevent leakage or escape of the radioactive material. It is a solid form of radioactive material which is not exempt from regulatory control and may be subject to transaction reporting, depending on the activity level of the source. For the purpose of this Directive, the term radioactive sealed source includes RTG’s but does not include material encapsulated solely for disposal; or nuclear material contained in a nuclear weapon; or in any nuclear reactor fuel assembly, subassembly, fuel rod, or fuel pellet.