Final rule · 2026-13260

List of Approved Spent Fuel Storage Casks: NAC International, Inc., MAGNASTOR® Storage System, Certificate of Compliance No. 1031, Amendment Nos. 16 and 17 and Revisions to Amendment Nos. 0 Through 16

The U.S. Nuclear Regulatory Commission (NRC) is amending its spent fuel storage regulations by revising the NAC International, Inc. (NAC) MAGNASTOR[supreg] System listing within the "List of approved spent fuel storage casks" to include Amendment Nos. 16 and 17 and revisions to Amendment Nos. 0 through 16 to Certificate of Compliance (CoC) No. 1031. Amendment No. 16 revises the CoC to permit alternate methods for determining the free volume inside a loaded canister and for measuring helium to ensure that Technical Specification limits are met. It also clarifies that mixed loadings of different assembly types or subtypes within a single Transportable Storage Canister (TSC) are acceptable. Amendment No. 17 and revisions to Amendment Nos. 0 through 16 revise the CoC to incorporate changes to the design basis for the MAGNASTOR[supreg] storage system to correct an error with M5 fuel cladding material yield strength that was introduced in CoC No. 1031, Amendment No. 14 and the associated revisions to Amendment Nos. 0 through 13.