The U.S. Nuclear Regulatory Commission (NRC) is amending its spent fuel storage regulations by revising the Holtec International HI- STORM 100 Cask System listing within the "List of approved spent fuel storage casks" to include Amendment No. 15 to Certificate of Compliance No. 1014. Amendment No. 15 amends the certificate of compliance to add a new overpack and a new transfer cask, revise allowed content for storage, and make other changes to the storage system.