Dynamic Structural Analysis of the Model 9979 Type AF Shipping Packaging

This paper presents the dynamic structural analysis results of Model 9979 Type AF packaging under hypothetical accident conditions. The submitted compliance documentation, Safety Analysis Report for Packaging Model 9979, with the regulatory requirements in 10 CFR 71.73 was based on testing five full-scale prototype units by the Savannah River National Laboratory. According to the test results under accident conditions, the 55-gallon outer drum maintained structural integrity and retained the inner 30-gallon drum, while the 30-gallon drum maintained its confinement of the contents. However, we identified several structural-related issues during our technical evaluation of the report — specifically, whether the structural tests were performed under the worst conditions and/or in the worst test sequence that would yield the most cumulative damage to the packaging. These structural-related issues were evaluated using the finite-element code ABAQUS. The dynamic structural analysis results show that a packaging with the full payload would indeed experience more damage during the drop test than a packaging without the payload. The analysis results also indicate that a corner drop of a fully loaded packaging, followed by a corner crush test, is the worst test sequence and results in highly localized plastic deformation of the 55-gallon outer drum, but no loss of its structural integrity. Both the test results and the dynamic structural analysis results demonstrated that the structural design and performance of the 9979 packaging are acceptable.