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

Document 2026-13260 is a Final Rule published by the Nuclear Regulatory Commission in the Federal Register on July 1, 2026, with an effective date of September 14, 2026. 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. View the original at https://www.federalregister.gov/documents/2026/07/01/2026-13260/list-of-approved-spent-fuel-storage-casks-nac-international-inc-magnastor-storage-system-certificate.

No. Document 2026-13260 is not classified as economically significant under Executive Order 12866. Economically significant rules require OIRA review and are estimated to have impacts of $100 million or more per year.