The Nuclear Regulatory Commission (NRC) is amending its regulations revising the NAC International (NAC) Universal Storage System (NAC-UMS) listing within the "List of approved spent fuel storage casks" to include Amendment No. 1 to the Certificate of Compliance (CoC). This amendment will allow holders of power reactor operating licenses as general licensees to store PWR design basis fuel assemblies in accordance with revised technical specifications and Maine Yankee site-specific spent fuel in the NAC-UMS. The changes for Amendment No. 1 to the NAC-UMS CoC include: changes to authorized contents to allow Maine Yankee site-specific spent fuels within the PWR basket, including damaged or consolidated fuel in a Maine Yankee fuel can and burnups up to 50,000 MWd/MTU; changes to allow longer times for PWR spent fuel cask loading operations based on reduced heat loads; authorization to store, without canning, intact PWR assemblies with missing grid spacers (up to an unsupported length of 60 inches); editorial clarifications to the technical specifications (TS); and deletion of a certificate reference to the NS-4-FR trade name of the solid neutron shielding material in the VCC shield plug.