IR 05000369/2025010
| 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
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 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
Inspection Report
Docket Numbers:
05000369 and 05000370
License Numbers:
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
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.
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.
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)
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.
- (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 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 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 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.
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-1206.47-69-
1001
AUXILIARY BUILDING FLOODING ANALYSIS
2/26/2018
MCC-1435.00-00-
21
NFPA 805 Transition NEI 04-02 B-2 Table - Nuclear
Safety Capability Assessment Methodology Review
Rev. 5
MCC-1435.00-00-
24
NFPA 805 Transition - NEI 04-02 B-3 Table Fire Area
Transition
Rev. 006
MCC-1435.00-00-
25
Nuclear Safety Capability Assessment (NSCA) For Fire
Protection Safe Shutdown Analysis In Support of NFPA
805 Transition
Rev. 002
MCC-1435.00-00-
28
NFPA 805 Transition B-1 Table/Report
Rev. 010
Calculations
MCC-1435.00-00-
0041
NFPA 805 Transition Risk-Informed Performance-Based
Fire Risk Evaluations
Rev. 004
Cabling for Power System Monitoring Panels in the 7kV
Switch...
3/15/2007
Corrective Action
Documents
OPS GUIDE 14-8 FOR CHECKING FIRE BRIGADE
GEAR AT BEGINNING O
2/22/2015
Unit 2 MD AFW Pump (CA) room floor drains
1/15/2025
Transient Combustibles Stored 926A RMC Room (U1 MG
Set Room)
1/18/2025
25 NRC TFPI: NFPA 805 Analysis Has a Deficient Safe
Shutdown Strategy
1/27/2025
25 NRC FPTI -Fire Brigade Gear Out of Date
1/27/2025
25 NRC FPTI: Inconsistency in Circuit Analysis data
between NSCA and FPRA mode
1/30/2025
During the 2025 NRC FPTI, the NRC identified a minor
violation...
1/30/2025
25 NRC FPTI Observation Improvement to AD-EG-ALL-
1117
1/30/2025
71111.21N.05
Corrective Action
Documents
Resulting from
Inspection
Unit 2 MD AFW Pump (CA) Room Floor Drains
01/15/2025
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
During the 2025 NRC FPTI, the NRC Identified a Minor
Violation
01/30/2025
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-
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-
21
U2 MDCA Pump Room Suppression Layout
06/28/1983
Engineering
Changes
Alternate CA Flow Control Methods
6/15/2023
Engineering
Evaluations
MCC-1435.00-00-
0046
NFPA 13 CODE CONFORMANCE REVIEW - MOTOR
DRIVEN CA PUMP ROOMS
04-01-2015
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
MCS-1465.00-00-
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
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
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
PM-2WM Piping-Inspect Floor Drains in U-2 CA Pump
Room
08/27/2020
Fire Barrier Inspection
07/07/2022
PM-2WM Piping-Inspect Floor Drains in U-2 CA Pump
Room
07/17/2023
PM-1WNPIPING-INSPECT 1A D/G ROOM FLOOR
DRAINS
24
PM-1WNPIPING-INSPECT 1B D/G ROOM FLOOR
DRAINS
24
Work Orders
PM-1WNPIPING-INSPECT 1B D/G ROOM FLOOR
DRAINS
25
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
PM-1WNPIPING-INSPECT 1A D/G ROOM FLOOR
DRAINS
25