IR 05000327/2025003
| ML25350C272 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/19/2025 |
| From: | Renee Taylor NRC/RGN-II/DORS/PB5 |
| To: | Erb D Tennessee Valley Authority |
| References | |
| EA-NMSS-2023-0002, EAF-NMSS-2025-0214 IR 2025003, IR 2024001 | |
| Download: ML25350C272 (0) | |
Text
SUBJECT:
SEQUOYAH UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000327/2025003, 05000328/2025003, AND 07200034/2024001 AND EXERCISE OF ENFORCEMENT DISCRETION
Dear Delson Erb:
On September 30, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Sequoyah Units 1 and 2. On October 1, 2025, the NRC inspectors discussed the results of this inspection with Ricardo Medina, Site Regulatory Compliance Manager, and other members of your staff. The results of this inspection are documented in the enclosed report.
Due to the temporary cessation of government operations, which commenced on October 1, 2025, the NRC began operating under its Office of Management and Budget-approved plan for operations during a lapse in appropriations. Consistent with that plan, the NRC operated at reduced staffing levels throughout the duration of the shutdown. However, the NRC continued to perform critical health and safety functions and make progress on other high-priority activities associated with the ADVANCE Act and Executive Order 14300. On November 13, 2025, following the passage of a continuing resolution, the NRC resumed normal operations. However, due to the 43-day lapse in normal operations, the Office of Nuclear Reactor Regulation granted the Regional Offices an extension on the issuance of the calendar year 2025 inspection reports that should have been issued by November 13, 2025, to December 31, 2025. The NRC resumed the routine cycle of issuing inspection reports on November 13, 2025.
The NRC identified a violation of Title 10 of the Code of Federal Regulations (CFR) 72.48, paragraphs (c)(1), (c)(2), and (d)(1), and provisions of 10 CFR 72.212 that resulted from a Certificate of Compliance (CoC) holders failure to comply with 10 CFR 72.48 for a CoC holder-generated design change to its multi-purpose canister (MPC) fuel basket, known as the continuous basket shim variant, which altered the structural configuration from welded to bolted shims. However, an Interim Enforcement Policy (IEP) issued in August 2025 is applicable to this violation. Specifically, Enforcement Policy Section 9.4, Enforcement Discretion for General Licensee Adoption of Certificate of Compliance Holder-Generated Modifications under 10 CFR Part 72.48, provides enforcement discretion to not issue an enforcement action for this violation. The licensee will be expected to comply with 10 CFR 72.212 provisions after the NRC December 19, 2025 dispositions the noncompliance for a CoC holder-generated change that affects the General Licensee.
If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555 0001; with copies to the Regional Administrator, Region II; the Director, Office of Enforcement; and the NRC Resident Inspector at Sequoyah Nuclear Plant.
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Ryan C. Taylor, Chief Projects Branch 5 Division of Operating Reactor Safety Docket Nos. 05000327, 05000328, and 07200034 License Nos. DPR-77 and DPR-79
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000327, 05000328 and 07200034
License Numbers:
Report Numbers:
05000327/2025003, 05000328/2025003, and 07200034/2024001
Enterprise Identifier:
I-2025-003-0026 and I-2024-001-0134
Licensee:
Tennessee Valley Authority
Facility:
Sequoyah Nuclear Plant
Location:
Soddy-Daisy, TN
Inspection Dates:
July 1, 2025 to September 30, 2025
Inspectors:
P. Cooper, Senior Reactor Inspector
P. Meier, Senior Resident Inspector
D. Neal, Health Physicist
A. Price, Resident Inspector
Approved By:
Ryan C. Taylor, Chief
Projects Branch 5
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Sequoyah, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
One violation of NRC requirements was identified. This violation is receiving Enforcement Discretion.
Additional Tracking Items
Type Issue Number Title Report Section Status EDG EAF-NMSS-2025-0214 Interim Enforcement Policy (IEP) Associated with the Continuous Basket Shim 60855 Closed LER 05000328/2025-002-00 LER 2025-002-00 for Sequoyah Nuclear Plant,
Unit 2, Manual Reactor Trip due to a Failed Closed Main Feedwater Regulating Valve 71153 Closed LER 05000327/2025-001-00 LER 2025-001-00 for Sequoyah Nuclear Plant,
Unit 1, Manual Reactor Trip due to Reboot of the Distributed Control System and Lowering Steam Generator Levels 71153 Closed LER 05000328/2024-001-01 LER 2024-001-01 for Sequoyah Nuclear Plant,
Unit 2, Reactor Trip due to an Electrical Trouble Turbine Trip 71153 Closed
PLANT STATUS
Unit 1 operated at or near 100 percent rated thermal power (RTP) for the entire inspection period.
Unit 2 began the inspection period at approximately 100 percent RTP. On September 3, 2025, unit 2 was reduced to approximately 15 percent RTP to remove the main generator and turbine from service for planned maintenance. The unit returned to 100 percent RTP on September 4, 2025 and remained at or near 100 percent RTP for the remainder of the inspection period.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
(1)unit 2 A charging pump during a planned maintenance outage of the B charging pump on July 21, 2025
- (2) B train emergency gas treatment system during planned maintenance and testing of the A train emergency gas treatment system on July 30, 2025 (3)unit 1 A train residual heat removal spray system while the B train system was out-of-service for planned maintenance on September 16, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
(1)unit 1 "A" 480-volt board room (FAA-094) on August 8, 2025 (2)125-volt DC vital battery board room III (FAA-087) on August 8, 2025 (3)125-volt DC vital battery board room IV (FAA-086) on August 8, 2025
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during the following activities:
- unit 2 load reduction to take the turbine and main generator offline to address turbine vibrations on September 3, 2025
- unit 2 synchronization and portions of the power ascension to 100 percent RTP on September 4, 2025
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)
- (1) The inspectors observed and evaluated licensed operator continual training annual exam (simulator) involving a main steam line break on August 19, 2025 (Scenario SX-26).
- (2) The inspectors observed and evaluated unit 1 refueling outage shutdown just-in-time-training performed in the simulator on September 24, 2025.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components remain capable of performing their intended function:
(1)fire/flood mode pumps used to mitigate the effects of the probable maximum flood analyzed in the updated final safety analysis report (2)unit 2 steam generator loop 1 main feedwater regulating valve (condition report [CR]
===2021913) (3)125-volt DC vital battery board II following a ground identified on August 12, 2025 (CR 2031806, 2032168)
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01)===
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
(1)maintenance activities associated with the 125-volt vital DC channel III battery charger, B spent fuel pool cooling pump rebuild, B diesel fire pump, L-B essential raw cooling water pump, and switchyard during the week of August 11, 2025
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (3 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
(1)impact of essential raw cooling water piping missile barrier removal identified on June 25, 2025 (CR 2022307)
(2)unit 1 reactor coolant system loop one hot leg resistance temperature detector failure identified on June 26, 2025 (CR 2022664)
(3)essential raw cooling water "A2A-A" strainer motor degraded identified on September 3, 2025 (CR 2035988)
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)
The inspectors evaluated the following temporary or permanent modifications:
(1)temporary mitigating actions to address shutdown board room temperatures in case of shutdown board room chiller failure (CR action 1742723-014; procedurally controlled temporary modification 1742723-018)
71111.24 - Testing and Maintenance of Equipment Important to Risk
The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:
Post-Maintenance Testing (PMT) (IP Section 03.01) (5 Samples)
(1)unit 1 A charging pump breaker swap and motor oil change on July 1, 2025 (work order [WO] 124365287, WO 124635773)
(2)unit 2 A containment spray heat exchanger inspection on July 14, 2025 (WO
===124197017) (3)unit 2 B charging pump breaker replacement on July 21, 2025 (WO 124224164, 125105313, 123789271)
(4)125-volt DC channel III battery charger 10-year maintenance during the week of August 11, 2025 (WO 124118471)
(5)1B emergency diesel generator battery charger supply breaker replacement on September 15, 2025 (WO 124550983)
Surveillance Testing (IP Section 03.01)===
(1)fire/flood mode pump surveillance performed on August 29, 2025 (0-PI-OPS-026-073.A)
(2)unit 1 "A" emergency diesel generator surveillance run on September 9, 2025 (1-SI-OPS-082-007.A, WO 124886839)
71114.06 - Drill Evaluation
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
(1)licensed operator continual training annual exam (simulator) involving a simulated credible security event requiring an emergency declaration on August 19, 2025 (Scenario SX-26)
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS05: Safety System Functional Failures (SSFFs) Sample (IP Section 02.04)===
(1)unit 1 (July 1, 2024, through June 30, 2025)
(2)unit 2 (July 1, 2024, through June 30, 2025)
MS06: Emergency AC Power Systems (IP Section 02.05) (2 Samples)
(1)unit 1 (July 1, 2024, through June 30, 2025)
- (2) unit 2 (July 1, 2024, through June 30, 2025)
MS07: High Pressure Injection Systems (IP Section 02.06) (2 Samples)
(1)unit 1 (July 1, 2024, through June 30, 2025)
- (2) unit 2 (July 1, 2024, through June 30, 2025)
MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)
(1)unit 1 (July 1, 2024, through June 30, 2025)
- (2) unit 2 (July 1, 2024, through June 30, 2025)
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
(1)unit 1 (July 1, 2024, through June 30, 2025)
- (2) unit 2 (July 1, 2024, through June 30, 2025)
MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)
(1)unit 1 (July 1, 2024, through June 30, 2025)
- (2) unit 2 (July 1, 2024, through June 30, 2025)
71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)
- (1) The inspectors reviewed the licensees corrective action program to identify potential trends in unit 2 main turbine elevated vibrations following a main generator rebuild in the spring of 2025 that might be indicative of a more significant safety issue (CR
===2028156, 2024128).
71153 - Follow-Up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)===
The inspectors evaluated the following licensee event reports (LERs):
- (1) LER 05000328/2024-001-01, Reactor Trip due to an Electrical Trouble Turbine Trip (ADAMS Accession No. ML25099A196), was evaluated. The previous LER submittal was reviewed in integrated inspection report 05000327/2025002 and
===05000328/2025002. The inspectors did not identify a performance deficiency or violation of NRC requirements. This LER is closed.
- (2) LER 05000327/2025-001-00, Manual Reactor Trip due to Reboot of the Distributed Control System and Lowering Steam Generator Levels (ADAMS Accession No.
ML25233A210), was evaluated. The inspectors did not identify a performance deficiency or violation of NRC requirements. This LER is closed.
- (3) LER 05000328/2025-002-00, Manual Reactor Trip due to a Failed Closed Main Feedwater Regulating Valve (ADAMS Accession No. ML25233A006), was evaluated. The inspectors did not identify a performance deficiency or violation of NRC requirements. This LER is closed.
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 60855 - Operation of an Independent Spent Fuel Storage Installation Inspections were conducted using the appropriate portions of the IPs in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2690, Inspection Program for Storage of Spent Reactor Fuel and Reactor-Related Greater-than-Class C Waste at Independent Spent Fuel Storage Installations (ISFSI) and for 10 CFR Part 71 Transportation Packagings."
Operation of an Independent Spent Fuel Storage Installation===
- (1) The inspector conducted a periodic in-office follow-up that focused on the review of the licensees implementation of the 10 CFR 72.48 process and associated corrective actions related to ISFSI activities. The review included:
- 72.48 evaluations and screenings: reviewed the licensees 72.48 process and associated evaluation associated with the adoption of the continuous basket shim (CBS) basket variant
- corrective action program: reviewed condition reports related to the design change of the CBS basket variant
INSPECTION RESULTS
Enforcement Discretion Enforcement Action EAF-NMSS-2025-0214: IEP associated with the Continuous Basket Shim 60855
Description:
Holtec International (also referred to as the certificate of compliance (CoC)holder) implemented a design change to its multipurpose canister (MPC) fuel basket, known as the CBS variant, which altered the structural configuration from welded to bolted shims.
This change resulted in a departure from the method of evaluation (MOE) described in the final safety analysis report (FSAR) used to establish the design-basis for tip-over events.
Holtec did not fully evaluate the cumulative impact of the MOE changes or apply them consistently within the licensing basis. As a result, the NRC issued three Severity Level IV violations to Holtec for noncompliance with 10 CFR 72.48 requirements (see NRC Inspection Reports 07201014/2022-201, Holtec International (ML23145A175) and 07201014/2022-201, Holtec International, Inc. - Notice of Violation (ML24016A190)).
When the licensee (also referred to as a General Licensee) chooses to adopt a change the CoC holder made pursuant to a CoC holder's change authority under 10 CFR 72.48 (referred to herein as a CoC holder-generated change), the licensee must perform a separate review using the requirements of 10 CFR 72.48(c). Accordingly, when the licensee chooses to adopt a CoC holder-generated change, and that change results in a non-conforming cask, there is a violation of 10 CFR 72.48 and certain provisions of 10 CFR 72.212 by the licensee, in addition to a CoC holder violation of 10 CFR 72.48.
In support of the 2022 loading campaign, the licensee adopted Holtecs generic design change, as documented in the "10 CFR 72.212 Report of Evaluations for HI-STORM FW System, Rev 5, and subsequently loaded casks using the CBS basket design. Because the CoC holder-generated change was found to be noncompliant by the NRC, the loaded casks at Sequoyah were also rendered non-conforming.
Corrective Actions: The licensee entered this into their corrective action program with actions to restore compliance with the 10 CFR 72.212 provisions that require each cask to conform to the terms, conditions, and specifications of a CoC or an amended CoC listed in 10 CFR 72.214.
Corrective Action References: 1907253
Enforcement:
Significance/Severity: The licensees failure to request that the CoC holder obtain an amendment prior to implementing the change was determined to be of Severity Level IV significance based on the guidance in Section 1.2.6.D of the NRC's Enforcement Manual.
The severity of the violation was determined based on its very low safety significance, as documented in NRC memorandum titled 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 (ADAMS Accession No. ML24018A085) and its similarity with violation example 6.1.d.2 in the NRCs Enforcement Policy.
Violation: 10 CFR 72.48 (c)(1) requires, in part, that licensee or certificate holder may make changes in the facility or spent fuel storage cask design as described in the FSAR (as updated), without obtaining:
- (ii) CoC amendment submitted by the certificate holder pursuant to § 72.244 if:
- (c) The change, test, or experiment does not meet any of the criteria in paragraph (c)(2) of this section.
10 CFR 72.48(c)(2) requires, in part, that a general licensee shall request that the certificate holder obtain a CoC amendment, prior to implementing a proposed change, if the change would: (viii) Result in a departure from an MOE described in the FSAR used in establishing the design bases or in the safety analyses.
10 CFR 72.48(d)(1) requires, in part, that the licensee shall have a written evaluation which provides the bases for the determination that the change does not require a CoC amendment pursuant to 72.48(c)(2).
10 CFR 72.212(b)(3) requires, in part, a general licensee must ensure that each cask used by the general licensee conforms to the terms, conditions, and specifications of a CoC or an amended CoC listed in 72.214.
Contrary to the above, since the 2022 loading campaign, the licensee failed to:
- (1) request Holtec, the certificate holder, obtain a CoC amendment for a change to the CBS cask design that resulted in a departure from an MOE described in the FSAR;
- (2) have a written evaluation providing the bases for the determination that the adopted change did not require a CoC amendment; and
- (3) ensure that the affected casks conformed to the terms, conditions, and specifications of the applicable CoC.
Specifically, Sequoyah's 10 CFR 72.48 titled 10 CFR 72.212 Report of Evaluations for HI-STORM FW System, Rev 5, failed to identify that the CBS variant design change resulted in a departure from a method of evaluation described in the FSAR used in establishing the design bases, failed to request the certificate holder obtain a CoC amendment pursuant to 10 CFR 72.244, and failed to ensure each cask conformed to the terms conditions, and specifications of a CoC or an amended CoC listed in 72.214, prior to using the CBS variant design.
Basis for Discretion: Section 9.4 of the Enforcement Policy, titled "Enforcement Discretion for General Licensee Adoption of Certificate of Compliance Holder-Generated Changes under 10 CFR 72.48" (ML25224A097), states that NRC will exercise enforcement discretion and not issue an enforcement action to a GL, for a noncompliance with the requirements of paragraphs (c)(1) and
- (2) and (d)(1) of 10 CFR 72.48 and with provisions of 10 CFR 72.212 that require GLs to ensure use of casks that conform to the terms, conditions and specifications of a CoC listed in 10 CFR 72.214, when the noncompliance results from a CoC holders failure to comply with 10 CFR 72.48 for a CoC holder-generated change. In support of the 2022 loading campaign, the licensee adopted a generic CoC holder design change (the CBS basket variant) and subsequently loaded the casks. On January 30, 2024, the NRC issued a notice of violation to the CoC holder, identifying the non-compliance, for the generic design change associated with the CBS basket variant (ML24016A190). As a result, the licensee became noncompliant due to the CoC holders failure to comply with 10 CFR 72.48 for the CoC holder-generated change. Since this violation meets the criteria of Section 9.4 of the policy, the NRC is exercising enforcement discretion by not issuing an enforcement action for this violation.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On October 1, 2025, the inspectors presented the integrated inspection results to Ricardo Medina, Site Regulatory Compliance Manager, and other members of the licensee staff.
- On November 20, 2025, the inspectors presented the ISFSI CBS Basket inspection results to Brian Cupp, Dry Cask Storage Manager, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
PM P0082
Fire / Flood Mode Pump A-A Flow Test - Preventive
Maintenance Frequency
Work Orders
21925241
Fire / Flood Mode Pump A-A Flow Test
10/31/2023
Work Orders
24253374
Fire / Flood Mode Pump A-A Flow Test
5/12/2025
Work Orders
25075144
Fire Protection Pump 1A Relief Valve - broken sensing line
01/19/2025