List of Approved Spent Fuel Storage Casks: NAC International, Inc., MAGNASTOR® Storage System, Certificate of Compliance No. 1031, Amendment No. 15

Document 2025-04650 is a Proposed Rule published by the Nuclear Regulatory Commission in the Federal Register on March 20, 2025. The U.S. Nuclear Regulatory Commission (NRC) is proposing to amend its spent fuel storage regulations by revising the NAC International, Inc. MAGNASTOR[supreg] Storage System listing within the "List of approved spent fuel storage casks" to include Amendment No. 15 to Certificate of Compliance No. 1031. Amendment No. 15 revises the certificate of compliance to add a new variation of the Lightweight MAGNASTOR[supreg] Transfer Cask design, add a new concrete cask design, increase the maximum system head load capacity, add new loading patterns, add a thermal shunt for short loading patterns, remove the 5 percent burnup penalty, increase Passive MAGNASTOR[supreg] Transfer Cask heat load, add two new pressurized-water reactor fuel types to support future operations, modify the transportable storage canister lid to allow additional clearance near the top center of the basket, and correct and clarify principal design criteria, operating procedures, and the acceptance criteria and maintenance program. This amendment also makes corresponding revisions to previously approved drawings for the concrete cask, Technical Specifications Appendix A and Appendix B, specific chapters of the final safety analysis report, and several license drawings. View the original at https://www.federalregister.gov/documents/2025/03/20/2025-04650/list-of-approved-spent-fuel-storage-casks-nac-international-inc-magnastor-storage-system-certificate.

No. Document 2025-04650 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.