The U.S. Nuclear Regulatory Commission (NRC) is amending its spent fuel storage regulations by revising the NAC International NAC- UMS[supreg] listing within the "List of approved spent fuel storage casks" to include Amendment No. 6 to Certificate of Compliance (CoC) No. 1015. Amendment No. 6 revises the CoC's technical specifications (TSs) to: Remove a redundant requirement for inspection of the concrete cask and canister; revise a limiting condition of operation (LCO) for heat removal to clarify that "LCO not met" means that the concrete heat removal system is inoperable; remove an inspection requirement that is already covered by LCO surveillance requirements for off- normal, accident, or natural phenomenon events; and clarify that "immediate" restoration of a concrete cask's heat removal capabilities means "within the design-basis time limit" in Section 11.2.13 of the Final Safety Analysis Report (FSAR), "or within the time limit for a less than design-basis heat load case, as evaluated." Amendment No. 6 also clarifies that an LCO for loaded cask surface dose rates applies prior to storage conditions, when dose rates will be highest.