The Nuclear Regulatory Commission (NRC) is amending its regulations by revising the Holtec International HI-STAR 100 cask system listing within the "List of approved spent fuel storage casks" to include Amendment No. 1 to the Certificate of Compliance (CoC). Amendment No. 1 revises the HI-STAR 100 cask system in seven areas and includes changes to the CoC and Technical Specifications. The seven areas involve: revision of the existing fuel specification tables; addition of pressurized water reactor Burnable Poison Rod Assemblies and Thimble Plug Devices; addition of two new classes of fuel to the fuel specification tables; addition of a new damaged fuel container; addition of thoria rods in canisters; addition of antimony-beryllium neutron sources [i.e., reactor startup sources]; and clarifications, editorial corrections, and other minor changes to cask design information and drawings. The CoC was revised to require users to prepare written acceptance tests and a maintenance program consistent with the technical basis described in the Safety Analysis Report (SAR). In addition, the amendment includes two minor changes to the HI-STAR 100 listing in the regulations. This amendment will allow the holders of power reactor operating licenses to store spent fuel in the HI-STAR 100 cask system, as amended, under a general license.