The U.S. Nuclear Regulatory Commission (NRC) is amending its spent fuel storage regulations by revising the Holtec International Storage Module Flood/Wind (HI-STORM FW) Multipurpose Canister Storage System listing within the "List of approved spent fuel storage casks" to include Amendment No. 6 to Certificate of Compliance No. 1032. Amendment No. 6 revises and clarifies design and operational requirements in the certificate of compliance for the HI-STORM FW overpack. This amendment also incorporates additional clarifications as well as editorial changes that do not change the substantive technical information of the certificate of compliance.