ML25045A156
| ML25045A156 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/19/2025 |
| From: | Daniel Bacon NRC/RGN-II/DORS/PB2 |
| To: | Pigott E Duke Energy Carolinas |
| References | |
| IR 2025010 | |
| Download: ML25045A156 (1) | |
Text
Edward Pigott Site Vice President Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078-8985
SUBJECT:
MCGUIRE NUCLEAR STATION - FIRE PROTECTION TEAM INSPECTION REPORT 05000369/2025010 AND 05000370/2025010
Dear Edward Pigott:
On January 30, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at McGuire Nuclear Station and discussed the results of this inspection with Samuel Hylton and other members of your staff. The results of this inspection are documented in the enclosed report.
One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
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 McGuire Nuclear Station.
February 19, 2025
E. Pigott 2
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, Daniel M. Bacon, Chief Engineering Br 2 Division of Operating Reactor Safety Docket Nos. 05000369 and 05000370 License Nos. NPF-9 and NPF-17
Enclosure:
As stated cc w/ encl: Distribution via LISTSERV Signed by Bacon, Daniel on 02/19/25
SUNSI Review X
Non-Sensitive
Sensitive X
Publicly Available
Non-Publicly Available OFFICE RII/DORS RII/DORS RII/DORS RII/DORS NAME L. Jones L. Colon-Fuentes C. Safouri D. Bacon DATE 02/18/25 02/18/25 02/19/25 02/19/25
Enclosure U.S. NUCLEAR REGULATORY COMMISSION Inspection Report Docket Numbers:
05000369 and 05000370 License Numbers:
NPF-9 and NPF-17 Report Numbers:
05000369/2025010 and 05000370/2025010 Enterprise Identifier:
I-2025-010-0040 Licensee:
Duke Energy Carolinas, LLC Facility:
McGuire Nuclear Station Location:
Huntersville, NC Inspection Dates:
January 13, 2025 to January 30, 2025 Inspectors:
L. Colon Fuentes, Construction Project Inspector L. Jones, Senior Reactor Inspector J. Montgomery, Senior Reactor Inspector C. Safouri, Senior Resident Inspector Approved By:
Daniel M. Bacon, Chief Engineering Br 2 Division of Operating Reactor Safety
2
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a fire protection team inspection at McGuire Nuclear Station, 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 Failure To Identify Variance From Deterministic Requirement For Two Fire Areas Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000369,05000370/2025010-01 Open/Closed None (NPP) 71111.21N.
05 The inspectors identified a Green finding and associated Non-cited Violation (NCV) of NFPA 805 Section 4.2.4.2 when the licensee failed to identify 2 variances from deterministic requirements as a part of its fire risk evaluation.
Additional Tracking Items None.
3 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 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 71111.21N.05 - Fire Protection Team Inspection (FPTI)
Structures, Systems, and Components (SSCs) Credited for Fire Prevention, Detection, Suppression, or Post-Fire Safe Shutdown Review (IP Section 03.01) (4 Samples)
The inspectors verified that components and/or systems will function as required to support the credited functions stated for each sample. Additional inspection considerations are located in the fire hazards analysis (FHA) or safe shutdown analysis (SSA).
(1)
Sprinkler system in FA 3 (Unit 2 Motor Driven CA Pump Room)
(2)
Halon System in FA 3A (Unit 2 Turbine Driven CA Pump Room)
(3)
Unit 2 Reactor Coolant (NC) System (4)
Unit 2 600V Electrical Distribution System Fire Protection Program Administrative Controls (IP Section 03.02) (1 Sample)
The inspectors verified that the selected control or process is implemented in accordance with the licensees current licensing basis. If applicable, ensure that the licensees FPP contains adequate procedures to implement the selected administrative control. Verify that the selected administrative control meets the requirements of all committed industry standards.
(1)
Fire Brigade Fire Protection Program Changes/Modifications (IP Section 03.03) (1 Sample)
The inspectors verified the following:
- a. Changes to the approved FPP do not constitute an adverse effect on the ability to safely shutdown.
- b. The adequacy of the design modification, if applicable.
- c. Assumptions and performance capability stated in the SSA have not been degraded through changes or modifications.
- d. The FPP documents, such as the Updated Final Safety Analysis Report, fire protection report, FHA, and SSA were updated consistent with the FPP or design change.
- e. Post-fire SSD operating procedures, such as abnormal operating procedures, affected by the modification were updated.
4 (1)
MNS-2023-001, Alternative CA Flow Control Methods (associated with EC 421795)
INSPECTION RESULTS Failure To Identify Variance From Deterministic Requirement For Two Fire Areas Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000369,05000370/2025010-01 Open/Closed None (NPP) 71111.21N.0 5
The inspectors identified a Green finding and associated Non-cited Violation (NCV) of NFPA 805 Section 4.2.4.2 when the licensee failed to identify 2 variances from deterministic requirements as a part of its fire risk evaluation.
==
Description:==
Establishment of the risk-informed, performance-based fire protection program requires establishing methodologies to assure that systems and features required to achieve the performance criteria in NFPA 805 Section 1.5 are available in response to a fire in a given area of the plant that damages equipment. One of the performance criteria in Section 1.5 is decay heat removal. For a fire in fire areas (FAs) 2A or 3A (Unit 1 and 2 Turbine Driven Auxiliary Feedwater Pump Rooms, respectively), the licensee's Nuclear Safety Capability Assessment (NSCA) credits the use of the B-train of Auxiliary Feedwater (AFW) to feed the C and D steam generators to assure decay heat removal.
To demonstrate compliance with the performance criteria in NFPA 805 Section 1.5, licensees determine the shutdown methodology they would like to credit, and use, either, a deterministic or performance-based approach to demonstrate that the selected strategy will not be adversely impacted by a fire. For FAs 2A and 3A, the licensee credited a performance-based approach. The performance-based approach utilized by the licensee was the use of a fire risk evaluation. The fire risk evaluation compares risk associated with implementation of a deterministic approach to meet the selected shutdown methodology with the risk of the proposed performance-based approach. This means that, for FAs where the licensee credits a fire risk evaluation, all potential impacts on the selected shutdown methodology, from a deterministic perspective, must be identified. These impacts are called variances from deterministic requirements (VFDRs).
For FAs 2A and 3A, the cable impact report of the NSCA identified that cables associated with valves 1/2CA-40B and 1/2CA-44B could be affected. These are air-operated valves that control flow to the C and D steam generators. The cable impact report concluded that a fire in FAs 2A or 3A could cause a loss of power and/or control of the valves. Fires in these areas could cause valves 40B and 44B to fail open, which could lead to overfill of the steam generator. However, this potential impact was not captured as a VFDR. As a result, a fire risk evaluation for this condition had not been performed.
Separate from the NSCA, in 2023, the licensee implemented EC 421795, which established alternate methods for AFW flow control for a large number of operational event response procedures. This modification was implemented because it was discovered that there is a potential for thermally induced pressure locking of the normal AFW flow control valves (to include valves 40B and 44B) if they are fully closed for any reason. To compensate for this possibility, alternate methods were established to assure that operators would always be able to maintain AFW flow control in the event that the flow control valves would not reopen. To compensate for potential fire-induced failure of these valves, the NSCA credited establishing
5 flow control via throttling downstream motor operated valves 1/2CA-42B and 1/2CA-46B from the main control room. However, the EC concluded that this is not feasible because the motor operated valves do not contain jog circuits, and as a result, the valves are only able to be positioned fully open or fully closed from the main control room and may not be able to re-open when flow to a steam generator needs to be reestablished.
In EC 421795, the licensee's evaluation of the effect of the potential flow control valve pressure locking on the strategies described in the NSCA only focused on fires in areas that credited the Standby Shutdown Facility SSF to maintain safe and stable conditions. The EC evaluation of the effect on the NSCA failed to account for areas that credited using the motor operated valves to maintain flow control. Therefore, the licensee's evaluation as a part of the EC was inadequate.
In conclusion, as a result of the team's discovery, the licensee had to perform the proper fire risk evaluation to account for the difference in risk between the deterministic and performance-based approach, and also had to add a defense-in-depth recovery action to the NSCA because the original analyzed method to compensate for a failure of valves 40B or 44B was demonstrated to be inadequate. The new recovery action manually throttles upstream AFW pump discharge 1/2CA-88 to control flow to the C and D steam generators.
Corrective Action References: The licensee wrote AR 2542032 in response to this issue.
Performance Assessment:
Performance Deficiency: The licensees failure to identify a variance from the deterministic requirements for fires in FA 2A and 3A in accordance with NFPA 805 Section 4.2.4.2 was a performance deficiency. Specifically, the cable report for these FAs identified cables that, if affected by fire, could result in loss of power/control of the credited CA flow control valves, 1/2CA-40B and 1/2CA-44B for each unit. However, this possibility was not identified as a VFDR, and as a result, the risk associated with these variances was not evaluated.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. Inspectors answered "no" to question 1.4.7-C of IMC 0609 Appendix F, Does the fire finding adversely affect the ability to reach and maintain hot shutdown/hot standby or safe and stable conditions using the credited safe shutdown success path? The failure of the cables in question would cause the CA FCVs to fail open, which is desired. However, the failure would result in the loss of ability to throttle flow to the SGs, which could lead to SG overfill.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.
Enforcement:
Violation: McGuire license condition 2.C(4) for Units 1 & 2, respectively, states, in part, Duke Energy Carolinas, LLC shall implement and maintain in effect all provisions of the approved
6 fire protection program that complies with 10 CFR 50.48(a) and 10 CFR 50.48(c). 10 CFR 50.48(c) incorporates the NFPA 805, Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants, 2001 Edition. NFPA 805 section 4.2.4.2, Use of Fire Risk Evaluation states, in part, Use of fire risk evaluation for the performance-based approach shall consist of an integrated assessment of the acceptability of risk, defense-in-depth, and safety margins. The evaluation process shall compare the risk associated with implementation of the deterministic requirements with the proposed alternative.
Contrary to the above, since 7/20/2017, the licensee did not compare the risk associated with implementation of the deterministic requirements with the proposed alternative.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS The inspectors verified no proprietary information was retained or documented in this report.
On January 30, 2025, the inspectors presented the fire protection team inspection results to Samuel Hylton and other members of the licensee staff.
7 DOCUMENTS REVIEWED Inspection Procedure Type Designation Description or Title Revision or Date MCC -1381.05-00-0335 Unit 1/2, NFPA 805 Circuit Breaker and Fuse Coordination Study Rev. 035 MCC-1206.47 1001 AUXILIARY BUILDING FLOODING ANALYSIS 02/26/2018 MCC-1435.00 0021 NFPA 805 Transition NEI 04-02 B-2 Table - Nuclear Safety Capability Assessment Methodology Review Rev. 5 MCC-1435.00 0024 NFPA 805 Transition - NEI 04-02 B-3 Table Fire Area Transition Rev. 006 MCC-1435.00 0025 Nuclear Safety Capability Assessment (NSCA) For Fire Protection Safe Shutdown Analysis In Support of NFPA 805 Transition Rev. 002 MCC-1435.00 0028 NFPA 805 Transition B-1 Table/Report Rev. 010 Calculations MCC-1435.00 0041 NFPA 805 Transition Risk-Informed Performance-Based Fire Risk Evaluations Rev. 004 AR 1631052 Cabling for Power System Monitoring Panels in the 7kV Switch...
3/15/2007 Corrective Action Documents NCR 01701477 OPS GUIDE 14-8 FOR CHECKING FIRE BRIGADE GEAR AT BEGINNING O 02/22/2015 AR 2540900 Unit 2 MD AFW Pump (CA) room floor drains 1/15/2025 AR 2541142 Transient Combustibles Stored 926A RMC Room (U1 MG Set Room) 1/18/2025 AR 2542032 2025 NRC TFPI: NFPA 805 Analysis Has a Deficient Safe Shutdown Strategy 1/27/2025 AR 2542033 2025 NRC FPTI -Fire Brigade Gear Out of Date 1/27/2025 AR 2542594 2025 NRC FPTI: Inconsistency in Circuit Analysis data between NSCA and FPRA mode 1/30/2025 AR 2542616 During the 2025 NRC FPTI, the NRC identified a minor violation...
1/30/2025 AR 2542637 2025 NRC FPTI Observation Improvement to AD-EG-ALL-1117 1/30/2025 71111.21N.05 Corrective Action Documents Resulting from Inspection AR02540900 Unit 2 MD AFW Pump (CA) Room Floor Drains 01/15/2025
8 Inspection Procedure Type Designation Description or Title Revision or Date AR02542616 During the 2025 NRC FPTI, the NRC Identified a Minor Violation 01/30/2025 WR 20281785 Door Stop Needs Relocating/Reinstalling 1/14/2025 MC-1220-12 Auxiliary Building Units 1 & 2 Floor Drain Layout Revision 10 MC-1220-13 Auxiliary Building units Units 1 & 2 Floor Drain Layout Revision 13 MC-1315-06.01-001 Penetration Seal Configuration Mechanical Penetration Seal Firestop Design Details M-1 Revision 0 MC-1705-03.01 One and Three Line Diagram 250/125VDC Auxiliary Power System Standby Shutdown Facility Rev. 42 MC-1716-02.03 Connection Diagram Standby Shutdown Facility Control Panel SSFCP Rev. 46 MC-2716-04.04 Connection Diagram Standby Shutdown Facility Auxiliary Relay Cabinet 2SSFARC Right Half Rev. 11 MC-2717-04.02-03 Connection Diagram Area Terminal Cabinet No. 2ATC4A (Train B) Right Half Rev. 43 MC-2731-01.07 Outline - Connection Diagram Reactor Coolant (NC)
System Standby Shutdown Facility Disconnect Enclosure Rev. 3 MCEE-250-00.31 Elementary Diagram Reactor Vessel Vent. Head System (NC) Solenoid Vlvs. 2NC274B, 2NC275B Rev. 5 MCEE-250-00.32 McGuire Nuclear Station Unit #2 Elementary Diagram Reactor Vessel Vent Head System (NC) SSF Controls Pwr Transfer & Alarm Relays Rev. 3 MCEE-250-00.33 McGuire Nuclear Station Unit #2 Elementary Diagram Reactor Vessel Vent. Head System (NC) SSF Controls for Sol. Vlvs. 2NC272A & 273A Rev. 7 MCEE-250-00.34 Elementary Diagram Pressurizing Spray Valves Positioner Air Block Solenoids 2NCS0270, 2NCS0271, 2NCS0290, 2NCS0291 Drawings MCM-2206.07-0021 U2 MDCA Pump Room Suppression Layout 06/28/1983 Engineering Changes EC 421795 Alternate CA Flow Control Methods 6/15/2023 Engineering Evaluations MCC-1435.00 0046 NFPA 13 CODE CONFORMANCE REVIEW - MOTOR DRIVEN CA PUMP ROOMS 04-01-2015
9 Inspection Procedure Type Designation Description or Title Revision or Date MCS-1465.00 0008 Plant Design Basis Specification for Fire Protection Revision 27 Fire Plans CSD-FP-ALL-1532-01 Pre-Fire Plan Maintenance Revision 0 AD-EG-ALL-1117 Design Analyses and Calculations Rev. 12 AD-EG-ALL-1176 Preparation of Engineering Documents Rev. 8 AD-FP-ALL-1532 NFPA 805 Pre-Fire Plans Revision 0 AD-HU-ALL-0004 PROCEDURE AND WORK INSTRUCTION USE AND ADHERENCE REVISION 17 AD-HU-ALL-0005 HUMAN PERFORMANCE TOOLS REVISION 7 AD-MN-ALL-0004 MINOR MAINTENANCE REVISION 9 AD-MN-ALL-1000 CONDUCT OF MAINTENANCE REVISION 25 AD-OP-ALL-0102 OPERATIONAL DECISION MAKING REVISION 4 AD-OP-ALL-0106 CONDUCT OF INFREQUENTLY PERFORMED TESTS OR EVOLUTIONS REVISION 4 AD-OP-ALL-0108 TURNOVER AND SHIFT BRIEF PROCESS REVISION 3 AD-OP-ALL-0207 FIRE BRIGADE AMINISTRATIVE CONTROLS REVISION 6 AD-PI-ALL-0100 Corrective Action Program Revision 30 AD-TQ-ALL-0086 FIRE BRIGADE AND HAZMAT TRAINING REVISION 6 AP/0/A/5500/45 Plant Fire or Turbine Bldg Oil System Leak Rev. 20 Procedures AP/2/A/5500/24 Loss of Plant Control Due To Fire or Sabotage Rev. 38 WO20388350 PM-2WM Piping-Inspect Floor Drains in U-2 CA Pump Room 08/27/2020 WO20469852 Fire Barrier Inspection 07/07/2022 WO20607110 PM-2WM Piping-Inspect Floor Drains in U-2 CA Pump Room 07/17/2023 WO20609357 PM-1WNPIPING-INSPECT 1A D/G ROOM FLOOR DRAINS 2024 WO20609357 PM-1WNPIPING-INSPECT 1B D/G ROOM FLOOR DRAINS 2024 Work Orders WO20708251 PM-1WNPIPING-INSPECT 1B D/G ROOM FLOOR DRAINS 2025
10 Inspection Procedure Type Designation Description or Title Revision or Date WO20708251 PM-1WNPIPING-INSPECT 1A D/G ROOM FLOOR DRAINS 2025