Holtec International Storage Module Underground MAXimum Capacity

callaway_first-6-canistersHI-STORM UMAX (Holtec International Storage Module Underground MAXimum Capacity) is an underground Vertical Ventilated Module (VVM) dry spent fuel storage system engineered to be fully compatible with all presently certified multi-purpose canisters (MPCs) under USNRC CoC 72-1014 (HI-STORM 100 dry cask storage system) and CoC 72-1032 (HI-STORM FW dry cask storage system).

Each HI-STORM UMAX Vertical Ventilated Module (VVM) provides storage of an MPC in the vertical configuration inside a cylindrical cavity located entirely below the top-of-grade of the ISFSI. The VVM, akin to the aboveground overpack, is comprised of the Cavity Enclosure Container (CEC) and the Closure Lid, as well as the interfacing structures.