# 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
> **Nuclear Regulatory Commission** · Direct final rule. · Published 2026-07-01 · Effective 2026-09-14 · 91 FR 39843
## Document
- **Document number:** 2026-13260
- **Category:** nuclear-waste
- **Sub-agency:** Nuclear Regulatory Commission
- **Federal Register citation:** 91 FR 39843
- **CFR reference:** 10 CFR 72
- **Publication date:** 2026-07-01
- **Effective date:** 2026-09-14
- **Energy docket:** NRC-2026-2047
## Abstract

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.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2026/07/01/2026-13260/list-of-approved-spent-fuel-storage-casks-nac-international-inc-magnastor-storage-system-certificate)
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