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. 4 to Certificate of Compliance No. 1040. Amendment No. 4 revises the certificate of compliance to update the technical specifications for radiation protection regarding the dose rate limit for the vertical ventilated module lid, update the technical specifications for the vent blockage limiting condition for operation, and add a Type 1 version of multi-purpose canister MPC-37.