Spent targets (Tritium Producing Burnable Absorber Rods, TPBARs) from the Commercial Light Water Reactor-Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site will be sent to waste disposal contained in a so-called ''overpack''. The tritium permeation rate through a welded stainless steel overpack was estimated using a finite difference computer program in a previous report. This report is an evaluation of tritium permeation through three additional overpack designs: (1) a stainless steel overpack sealed using a mechanical closure with a metal gasket, (2) a mild steel overpack with the same mechanical closure, and (3) an aluminum overpack sealed by welding.