The U.S. Nuclear Regulatory Commission (NRC) is amending its spent fuel storage regulations by revising the Holtec International HI- STORM UMAX Canister Storage System listing within the "List of approved spent fuel storage casks" to include Amendment No. 5 to Certificate of Compliance No. 1040. Amendment No. 5 revises the certificate of compliance to include two new versions of the HI-STORM UMAX design (Version B1 and B2).