Comparison of Analytical and Physical Testing Results for the DPP-2 Shipping Package

The DPP-2 is a Type B fissile material shipping package developed by the Y-12 National Security Complex in Oak Ridge, Tennessee, in 2002–03. Currently, the DPP-2 is undergoing certification review by the Packaging Certification Division (PCD) of the National Nuclear Security Administration (NNSA) Service Center in Albuquerque, New Mexico, U.S.A. Issuance of an Offsite Transportation Certificate (OTC) for this package is expected in the near future. The DPP-2 is a drum-type package and is approximately 28.7 in. tall and 24.7 in. in diameter, as shown in Fig. 1. The overpack is manufactured using a stainless steel drum as the starting point. A piece of formed angle iron is welded to the top of the drum to facilitate the attachment of both weld studs for drum-lid capture as well as an inner liner. The volume between the drum and the inner liner is an annular space filled with an inorganic impact-limiting and thermal-insulating material called Kaolite 1600TM. The containment vessel (CV) is made of stainless steel and sits within the inner liner. The CV lid is attached to the CV body with 16 high-strength cap screws. Two elastomeric O-rings are used at the CV–lid interface; the inner one forms a portion of the containment boundary, and the outer one facilitates leak testing. Above the CV and within the inner liner is the removable top plug, which consists of a stainless steel shell and Kaolite 1600TM filling. A special feature of the DPP-2 design is the two metal hoops placed on the outside of the drum, one near the top and one near the bottom. The hoops help limit damage from crush tests that impact the side of the package (see Fig. 1). For this reason, the hoops are referred to as crush rings.