Justification for Onsite Transfer of Type B Packages After Extended Storage

This paper offers a practical means of qualifying previously loaded Type B packages for transportation onsite within the DOE complex after years of protected storage, while supporting the DOE program to maintain radworker dose as low as reasonable achievable (ALARA). Specifically, the paper discusses relevant packaging components and introduces part of a surveillance program carried out at the Savannah River Site supporting long-term storage of 3013-processed plutonium-bearing materials within closed 9975 packages and its application to DOE’s Equivalent Safety. Under normal service, maintenance is carried out annually to re-qualify the 9975 packagings for leak-tight transportation service. While in storage, however, annual maintenance was judged not to provide a significant increase in safety but to increase storage operation costs and to violate ALARA principles. Hence, a surveillance program was developed to investigate and confirm predictions of storage-related behavior for 9975 packaging materials, including the performance of O-ring seals and Celotex^® insulation. The combination of analytical evaluations with surveillance data is shown sufficient to ensure that the 9975 packages can accommodate 1) time at storage temperature and 2) cumulative radiation dose without compromising subsequent performance under regulatory Normal Conditions of Transport or site-specific credible accident conditions.