[en] The ORNL uranium-shielded shipping casks, models L and M, are type B packages for large-quantity radioactive material shipments. There are seven casks altogether: six model L's and one model M. The model L casks are identified by Oak Ridge National Laboratory (ORNL) as 14 UC, Nos. 2, 3, 4, 5, 6, and 7; and model M is identified as 13 UC-1. Materials to be shipped in the casks are nonfissile radionuclides. The casks are similar, model L being slightly larger than model M. Both casks were fabricated at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky, using the same general fabrication techniques