2024-08180. Tennessee Valley Authority; Watts Bar Nuclear Plant, Units 1 and 2; Independent Spent Fuel Storage Installation; Environmental Assessment and Finding of No Significant Impact

AGENCY:

Nuclear Regulatory Commission.

ACTION:

Notice; issuance.

SUMMARY:

The U.S. Nuclear Regulatory Commission (NRC) is issuing an environmental assessment (EA) and a finding of no significant impact (FONSI) for an exemption request submitted by Tennessee Valley Authority (TVA) that would permit Watts Bar Nuclear Plant (WBN) to load five new 37 multi-purpose canisters (MPC) with continuous basket shims (CBS) beginning July 2024 in the HI-STORM Flood/Wind (FW) MPC Storage System at its Watts Bar Units 1 and 2 independent spent fuel storage installation (ISFSI) in a storage condition where the terms, conditions, and specifications in the Certificate of Compliance (CoC) No. 1032, Amendment No. 0, Revision No. 1 are not met.

DATES:

The EA and FONSI referenced in this document are available on April 17, 2024.

ADDRESSES:

Please refer to Docket ID NRC-2024-0064 when contacting the NRC about the availability of information regarding this document. You may obtain publicly available information related to this document using any of the following methods:

• Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2024-0064. Address questions about Docket IDs in Regulations.gov to Stacy Schumann; telephone: [phone]; email: [e-mail]. For technical questions, contact the individual listed in the For Further Information Contact section of this document.

• NRC's Agencywide Documents Access and Management System (ADAMS): You may obtain publicly available documents online in the ADAMS Public Documents collection at https://www.nrc.gov/​reading-rm/​adams.html. To begin the search, select “Begin Web-based ADAMS Search.” For problems with ADAMS, please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, or by email to [e-mail]. For the convenience of the reader, instructions about obtaining materials referenced in this document are provided in the “Availability of Documents” section.

• NRC's PDR: The PDR, where you may examine and order copies of publicly available documents, is open by appointment. To make an appointment to visit the PDR, please send an email to [e-mail] or call 1-800-397-4209 or 301-415-4737, between 8 a.m. and 4 p.m. eastern time (ET), Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

John-Chau Nguyen, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555; telephone: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

I. Introduction

The NRC is reviewing an exemption request from TVA, dated February 28, 2024, and supplemented on March 18, 2024. TVA is requesting an exemption, pursuant to section 72.7 of title 10 of the Code of Federal Regulations (10 CFR), in paragraphs 72.212(a)(2), 72.212(b)(3), 72.212(b)(5)(i), 72.212(b)(11), and 72.214 that require TVA to comply with the terms, conditions, and specifications of CoC No. 1032, Amendment No. 0, Revision No. 1. If approved, the exemption would allow TVA to load five MPC-37-CBS beginning July 2024 in the HI-STORM FW MPC Storage System at the WBN ISFSI in a storage condition where the terms, conditions, and specifications in CoC No. 1032, Amendment No. 0, Revision No. 1, are not met.

II. Environmental Assessment

Background

WBN is located in Rhea County, Tennessee, on the west bank of the Tennessee River at Tennessee River Mile 528. Unit 1 began operating in 1996 and Unit 2 began operating in 2016. TVA has been storing spent fuel in an ISFSI at WBN under a general license as authorized by 10 CFR part 72, subpart K, “General License for Storage of Spent Fuel at Power Reactor Sites.” TVA currently uses the HI-STORM FW MPC Storage System under CoC No. 1032, Amendment No. 0, Revision No. 1 for dry storage of spent nuclear fuel in a specific MPC ( i.e., MPC-37) at the WBN ISFSI.

Description of the Proposed Action

The CoC is the NRC approved design for each dry cask storage system. The proposed action would exempt the applicant from the requirements of 10 CFR 72.212(a)(2), 72.212(b)(3), 72.212(b)(5)(i), 72.212(b)(11), and 72.214 only as these requirements pertain to the use of the MPC-37-CBS in the HI-STORM FW MPC Storage System for the near-term planned loading of the systems. The exemption would allow WBN to load five MPC-37-CBS in the HI-STORM FW MPC Storage System at the WBN ISFSI beginning July 2024, despite the MPC-37-CBS in the HI-STORM FW MPC Storage System not being in compliance with the terms, conditions, and specifications in the CoC No. 1032, Amendment No. 0, Revision No. 1.

The HI-STORM FW MPC Storage System CoC provides the requirements, conditions, and operating limits necessary for use of the system to store spent fuel. Holtec International (Holtec), the designer and manufacturer of the HI-STORM FW MPC Storage System, developed a variant of the design with CBS for the MPC-37, known as MPC-37-CBS. Holtec originally implemented the CBS variant design under the provisions of 10 CFR 72.48, which allows licensees to make changes to cask designs without a CoC amendment under certain conditions (listed in 10 CFR 72.48(c)). After evaluating the specific changes to the cask designs, the NRC determined that Holtec erred when it implemented the CBS variant design under 10 CFR 72.48, as this was not the type of change allowed without a CoC amendment. For this reason, the NRC issued three Severity Level IV violations to Holtec. TVA plans to load five MPC-37-CBS in the HI-STORM FW MPC Storage System beginning in July 2024. This exemption considers the near-term planned loading of the five canisters with the CBS variant basket design.

Need for the Proposed Action

TVA requested this exemption in order to allow WBN to load five MPC-37-CBS in HI-STORM FW MPC Storage System at the WBN ISFSI for the future loading campaign scheduled to begin in July 2024. Approval of the exemption request would allow TVA to effectively manage the margin for full core reserve in the WBN spent fuel pool to enable refueling and offloading fuel from the reactor.

Environmental Impacts of the Proposed Action

This EA evaluates the potential environmental impacts of granting an exemption from the terms, conditions, and specifications in CoC No. 1032, Amendment No. 0, Revision No. 1. The exemption would allow five MPC-37- CBS to be loaded in the HI-STORM FW MPC Storage System in the near-term loading campaign and maintained in storage at the WBN ISFSI.

The potential environmental impacts of storing spent nuclear fuel in NRC-approved storage systems have been documented in previous assessments. On July 18, 1990 (55 FR 29181), the NRC amended 10 CFR part 72 to provide for the storage of spent fuel under a general license in cask designs approved by the NRC. The EA for the 1990 final rule analyzed the potential environmental impacts of using NRC-approved storage casks. The EA for the HI-STORM FW MPC Storage System, CoC No. 1032, Amendment No. 0, Revision No. 1, (80 FR 58195), published in 2015, tiers off of the EA issued for the July 18, 1990, final rule. “Tiering” off earlier EAs is a standard process encouraged by the regulations implementing the National Environmental Policy Act of 1969 (NEPA) that entails the use of impact analyses of previous EAs to bound the impacts of a proposed action where appropriate. The Holtec HI-STORM FW MPC Storage System is designed to mitigate the effects of design basis accidents that could occur during storage. Considering the specific design requirements for the accident conditions, the design of the cask would prevent loss of containment, shielding, and criticality control. If there is no loss of containment, shielding, or criticality control, the environmental impacts would not be significant.

The exemptions requested by TVA at the WBN site as they relate to CoC No. 1032, Amendment No. 0, Revision No. 1, for the HI-STORM FW MPC Storage System are limited to the use of the CBS variant basket design only for the near-term planned loading of five canisters utilizing the CBS variant basket design. The staff has determined that this change in the basket would not result in either radiological or non-radiological environmental impacts that significantly differ from the environmental impacts evaluated in the environmental assessment supporting the issuance of CoC No. 1032, Amendment No. 0, Revision No. 1. If the exemption is granted, there would be no significant change in the types or amounts of any effluents released, no significant increase in individual or cumulative public or occupational radiation exposure, and no significant increase in the potential for or consequences from radiological accidents. Accordingly, the Commission concludes that there would be no significant environmental impacts associated with the proposed action.

Alternative to the Proposed Action

The staff considered the no-action alternative. The no-action alternative (denial of the exemption request) would require TVA to keep the spent fuel in the spent fuel pool until older design canisters can be fabricated and delivered to site. Not allowing the planned future loading campaign could affect TVA's ability to manage pool capacity, reactor fuel offloading, and refueling. Any further delay would lead to insufficient space in the spent fuel pool for core offload and the shutdown of WBN Unit 2, which in turn would potentially impact the energy supply in the area. The NRC has determined that these potential impacts of the no-action alternative could be avoided by proceeding with the proposed exemption, especially given that the staff has concluded in NRC's Safety Determination Memorandum, issued with respect to the enforcement action against Holtec regarding these violations, that fuel can be stored safely in the MPC-37-CBS casks.

Agencies Consulted

The NRC provided the Tennessee Department of Environment and Conservation (TDEC) a copy of this draft EA for review by an email dated April 8, 2024. On April 9, 2024, the TDEC provided its concurrence by email.

III. Finding of No Significant Impact

The environmental impacts of the proposed action have been reviewed in accordance with the requirements in 10 CFR part 51, which implement NEPA. Based upon the foregoing environmental assessment, the NRC finds that the proposed action of granting the exemption from the regulations in 10 CFR 72.212(a)(2), 72.212(b)(3), 72.212(b)(5)(i), 72.212(b)(11) and 72.214, which require the licensee to comply with the terms, conditions, and specifications of the CoC, would not significantly impact the quality of the human environment. The exemption in this case would be limited to the specific future loading of five canisters with the CBS variant basket design. Accordingly, the NRC has determined that a finding of no significant impact (FONSI) is appropriate, and an environmental impact statement is not warranted.

IV. Availability of Documents

The documents identified in the following table are available to interested persons through ADAMS, as indicated.

Document description	ADAMS accession No. or Federal Register notice
TVA's request for exemption, dated February 28, 2024	ML24059A369.
Supplement to request for exemption, dated March 18, 2024	ML24078A257.
Certificate of Compliance No. 1032, Amendment 0, Revision 1, dated April 25, 2016	ML16112A306 (Package).
Notice of Violation; The U.S. Nuclear Regulatory Commission Inspection Report No. 07201014/2022-201, Holtec International, Inc.—EA-23-044, dated January 30, 2024	ML24016A190.
10 CFR part 72 amendment to allow spent fuel storage in NRC-approved casks, dated July 18, 1990	55 FR 29181.
EA for part 72 amendment to allow spent fuel storage in NRC-approved casks, dated March 8, 1989	ML051230231.
Final rule for List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Multipurpose Storage System, CoC No. 1032, Amendment 0, Revision 1, dated September 28, 2015	80 FR 58195.
Safety Determination of a Potential Structural Failure of the Fuel Basket During Accident Conditions for the HI-STORM 100 and HI-STORM Flood/Wind Dry Cask Storage Systems, dated January 31, 2024	ML24018A085.
NRC email to TDEC requesting review of EA/FONSI for Watts Bar Exemption, dated April 8, 2024	ML24100A840.
TDEC email response regarding review of EA/FONSI for Watts Bar Exemption, dated April 9, 2024	ML24100A839.

Dated: April 12, 2024.

For the Nuclear Regulatory Commission.

Yoira Diaz-Sanabria,

Chief, Storage and Transportation Licensing Branch, Division of Fuel Management, Office of Nuclear Material Safety and Safeguards.