The Nuclear Regulatory Commission (NRC) is amending its regulations revising the NAC International, Inc., NAC-Multi-Purpose Canister (MPC) system listing within the "List of Approved Spent Fuel Storage Casks" to include Amendment No. 5 to Certificate of Compliance (CoC) Number 1025. Amendment No. 5 will modify the CoC by revising the Technical Specifications (TS) to incorporate changes to the reporting and monitoring requirements to allow for visual inspection of the air inlet and outlet vents instead of thermal monitoring, revising the TS to incorporate guidance from NRC Interim Staff Guidance-22 and replace all references to backfilling the cask with air to backfilling with inert gas, revising the CoC description to remove the requirement for tamper-indicating devices on the Vertical Concrete Casks, and including several editorial changes to improve the clarity of the documents associated with the NAC-MPC system, under the general provisions that govern licensing requirements for the independent storage of spent nuclear fuel, high level radioactive waste, and reactor-related greater than Class C waste.