Encapsulation & Packaging
Field-Sealable Special Form Containers
Early in OSRP operational history, it was recognized that a method to qualify suspect or leaking sources as special form was needed. During a recovery in 1994, OSRP discovered a container, known as 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 sources as special form in Type A packaging for disposal. Shipment as Type A allowed 200 times more Ra-226 activity to be packaged and transported in a single container. OSRP staff first used the SFC-7 in the field to encapsulate a Pu-238/Beryllium source, thus making it "special form".
As recovery work accelerated in the later 1990s, an increased need arose to field-qualify sources as special form. However, the size limitations of the SFC-7 restricted its usefulness. After discussions with the RSO, Inc., it was agreed that LANL would take on the task of expanding the original RSO design into a suite of SFCs that would be fabricated in various sizes to accommodate the size range and isotopic variation of sealed sources likely to be encountered by OSRP; and which could be easily used at off-site recovery locations.
Using the original concept from RSO, OSRP designed and fabricated several prototypes and tested them 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: 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.
OSRP has developed three variations of a multifunction container called a POC (Pipe Overpack Component) to satisfy requirements for U.S. Department of Transportation (DOT) 7A Type A containers. These containers also qualify for use in the TRUPACT II overpack used to transport material to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, N.M. and serve as interim storage containers until disposition occurs.
Each POC incorporates neutron and/or gamma shielding to maintain radiation dose rates as low as possible. In addition, the containers: