Special Form Capsules (SFCs)

Early in the history of the OSR Project, it was recognized that some method to qualify suspect or leaking sources as special form was needed. During a recovery in 1994, the Project found a capsule, the SFC-7, which had been developed and patented by Radiation Service Organization, Inc. (RSO) in 1989. RSO had developed the SFC-7 to facilitate shipments of radium (Ra)-226 sources as special form in Type A packages for disposal. Shipment as Type A allowed 200 times more Ra-226 activity to be packaged and transported in a single container. The Project staff used the SFC-7 in the field to qualify a Pu-238/beryllium source as special form, which allowed the efficient recovery of the source to LANL.

As the work of the Project accelerated in the later 1990s, an increased need arose to field-qualify sealed sources as special form. However, the size limitations of the SFC-7 restricted its usefulness. After discussions with the RSO staff, it was agreed that LANL would take on the task of expanding the RSO design into a suite of SFCs that could be easily sealed in the field and be fabricated in various sizes to accommodate the full physical size and isotopic range of sealed sources likely to be encountered by the Project.

Using the original concept from RSO, the OSRP designed and fabricated several prototype capsules and tested them in-house at LANL against the special form requirements in 49 CFR 173.469.

The materials intended for encapsulation by the LANL SFC are limited to metal clad sealed sources or leaking sealed sources containing dry solids. In general, use of the SFC by LANL will be for radioactive sources containing the following alpha-emitting isotopes: Pu-238, Pu-239, Am-241, Np-237, Cm-244, and Ra-226. However, the potential radioactive contents of this capsule are limited only by the potential for pressurization of the capsule and/or the heat generated in the capsule by radioactive decay.

SFC Model I	SFC Model II	SFC Model III

For details on SFCs, read our reports and check out the SFC dimensions and assembly kit. For additional information, contact the OSRP staff at osrp@lanl.gov or call 1-877-676-1749.