Fabrication of the Mk-18A Transfer Cask

The Mk-18A transfer cask was designed for transfer of legacy Mk-18A target assemblies from the L-Basin Storage Area at the Savannah River Site (SRS) to the Savannah River National Laboratory (SRNL). SRNL needed to design a site-specific cask as all existing designs required extensive facility modifications to perform the necessary onsite shielding functions; in the L-Basin, during transfer, and at the SRNL. Once the design was approved, SRNL procurement requested quotes for its fabrication and awarded the contract to Petersen, Inc. in Ogden, Utah. This paper will provide a detailed look at how the Mk-18A will be used to accomplish the mission of recovering the Mk-18A target assemblies, it will briefly describe the process used at SRNL for procurement of radioactive material packagings, it will document and describe challenges in the fabrication of the cask, and it will explore requested design changes made by the fabricator and any impacts those changes have on the cask’s ability to meet its performance requirements.