IR 05000369/2023003
| ML23289A245 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, McGuire  |
| Issue date: | 10/24/2023 |
| From: | Eric Stamm Division Reactor Projects II |
| To: | Pigott E Duke Energy Carolinas |
| References | |
| IR 2023001 | |
| Download: ML23289A245 (1) | |
Text
SUBJECT:
MCGUIRE NUCLEAR STATION - INTEGRATED INSPECTION REPORT 05000369/2023003 AND 05000370/2023003; AND INSPECTION REPORT 07200038/2023001
Dear Edward Pigott:
On September 30, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at McGuire Nuclear Station. On October 18, 2023, the NRC inspectors discussed the results of this inspection with you 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 did not involve a violation of NRC requirements.
If you disagree with a finding not associated with a regulatory requirement in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; and the NRC Resident Inspector at McGuire Nuclear Station.
October 24, 2023 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, Eric J. Stamm, Chief Reactor Projects Branch 1 Division of Reactor Projects Docket Nos. 05000369 and 05000370;
07200038 License Nos. NPF-9 and NPF-17
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000369 and 05000370; 07200038
License Numbers:
Report Numbers:
05000369/2023003 and 05000370/2023003; 07200038/2023001
Enterprise Identifier:
I-2023-003-0019; I-2023-001-0100
Licensee:
Duke Energy Carolinas, LLC
Facility:
McGuire Nuclear Station
Location:
Huntersville, North Carolina
Inspection Dates:
July 1, 2023, to September 30, 2023
Inspectors:
C. Safouri, Senior Resident Inspector
F. Young, Resident Inspector
J. Bell, Senior Health Physicist
P. Boguszewski, Senior Resident Inspector
P. Cooper, Senior Reactor Inspector
J. Diaz-Velez, Senior Health Physicist
P. Gresh, Operations Engineer
B. Kellner, Senior Health Physicist
D. Neal, Health Physicist
A. Nielsen, Senior Health Physicist
J. Walker, Senior Emergency Preparedness Inspector
Approved By:
Eric J. Stamm, Chief
Reactor Projects Branch 1
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated 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 Implement Design Change Measures on Current Transformer Resulted in Unit 2 Turbine Runback Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05000370/2023003-01 Open/Closed None (NPP)71111.12 A self-revealed Green finding was identified when the licensee failed to meet licensee procedure EDM-101, Engineering Directive Manual-101, Engineering Calculations/
Analyses, Revision 15, which required the licensee to identify any special functional or physical interface requirements for systems or equipment affected by an engineering change.
Specifically, the licensee did not identify the impact on the current transformer mounting requirements associated with an engineering change to remove the shim material. The improper mounting of the current transformer resulted in a turbine runback.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000370/2023-001-00 LER 2023-001-00 for McGuire Nuclear Station,
Unit 2, Manual Actuation of the Unit 2 Motor Driven Auxiliary Feedwater Pumps 71153 Closed
PLANT STATUS
Unit 1 began the inspection period at or near 100 percent rated thermal power (RTP). On September 16, 2023, the unit was shut down for the remainder of the inspection period for a scheduled refueling outage (M1R29).
Unit 2 operated at or near 100 percent RTP for the entire 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 onsite 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
71111.01 - Adverse Weather Protection
Impending Severe Weather Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the adequacy of the overall preparations to protect risk significant systems from impending severe thunderstorm warnings, on August 29, 2023.
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) Auxiliary power system during restoration of a 120 VAC non-safety-related auxiliary control power panelboard inverter, KXA, to normal configuration, on July 20, 2023
- (2) Units 1/2 AC electrical power systems supplying offsite power to the onsite essential auxiliary power systems while in an off-normal alignment for the Unit 1 refueling outage, on September 20, 2023
- (3) Unit 1 train A/B spent fuel pool cooling system during the Unit 1 refueling outage, on September 26, 2023
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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 2 auxiliary feedwater pump room, on July 14, 2023
- (2) Unit 2 emergency diesel generator rooms, on July 28, 2023
- (3) Portions of service building 767 and 739 elevations, on August 25, 2023
- (4) Auxiliary building 750 elevation shared equipment area, on September 1, 2023
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated internal flooding mitigation protections in the:
- Unit 1 auxiliary feedwater pump rooms
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 Unit 1 shutdown and cooldown for refueling outage M1R29, on September 16, 2023.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (2 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
- (1) Nuclear condition report (NCR) 02468097, Unit 2 turbine runback maintenance rule plant level event, on August 24, 2023
- (2) NCR 02402035, Failure of Eaton/Aeroquip Flexmaster coupling on #1 emergency supplemental power supply diesel generator, on September 15, 2023
Quality Control (IP Section 03.02) (1 Sample)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:
- (1) Engineering change 410758, Unit 2 train B commercial grade dedicated lube oil hose connecting main oil header to instrumentation for low lube oil pressure trip, on August 2, 2023
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (5 Samples)
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) Work order (WO) 20612833, Unit 1 rod control power cabinet, 1BD, failure power supply light lit, on July 6, 2023
- (2) Work request (WR) 20251917, emergent work on Unit 1 train B spent fuel pool cooling pump motor inboard bearing temperature, on July 10, 2023
- (3) Unit 2 equipment protection plan during the unavailability of train A nuclear service cooling water discharge isolation valve to non-essential header, 2RN-40A, and emergency supplemental power source #1 and #2 for preventive maintenance, on July 18, 2023
- (4) Equipment protection plan for Unit 1 while in yellow shutdown risk for decay heat removal and lowered inventory, on September 20, 2023
- (5) Unit 1 fuel offload from the reactor core to the spent fuel pool during the Unit 1 refueling outage, on September 22, 2023
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) NCR 02478597, Unit 2 letdown relief valve, 2NV-6, leaking past seat, on July 8, 2023
- (2) WR 20252570, High containment radiation monitor, 1EMF-51A, noise, on July 20, 2023
- (3) NCR 02473777, Unit 2 main feedwater containment isolation valve air solenoid, 2CFSV0302, failure, on July 24, 2023
- (4) WO 20615451, Unit 2 loop A reactor coolant pump seal injection flow meter, 2NVLP5330, out of tolerance, on July 27, 2023
- (5) NCR 02464821, Unit 2 train B wide range neutron flux noise, on August 10, 2023
- (6) WR 20249180, Unit 2 train B nuclear service water backflush valve assured air supply accumulator, 2RN-25B, air pressure low, on September 26, 2023
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) Engineering change 422951, replacement of D87 on-delay timers with NTS 812 on-delay timers for relays DJ(2TRC) and FL(ARR), for Unit 2 train A/B emergency diesel generators, on September 6, 2023
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage Sample (IP Section 03.01) (1 Partial)
(1)
(Partial)
The inspectors evaluated Unit 1 refueling outage (M1R29) activities from September 16, 2023, to September 30, 2023. The inspectors completed inspection procedure Sections 03.01.a through 03.01.b.
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) (6 Samples)
- (1) WO 20568436, Unit 2 train A emergency diesel generator fuel oil day tank instrument calibration, on July 12, 2023
- (2) WO 20512778, Unit 2 train A emergency diesel generator breaker and auxiliary switch replacement, on July 13, 2023
- (3) WO 20562207, Unit 2 train A centrifugal charging pump motor inspection, on July 24, 2023
- (4) WO 20591172, Unit 1 train B emergency diesel generator hot web deflections and control circuit testing, on August 8, 2023
- (5) WO 20582499, Unit 2 turbine driven auxiliary feedwater pump discharge isolation valve to 2D steam generator, 2CA-38B, preventive maintenance, on August 9, 2023
- (6) WO 20621096, standby shutdown facility non-essential 600V load center, 1SLXG, charred relay replacement, on August 30, 2023
Surveillance Testing (IP Section 03.01) (2 Samples)
- (1) PT/1/A/4200/028A, for Unit 1 train A solid state protection system relay testing, on July 19, 2023
- (2) PT/1/A/4350/036B, for Unit 1 train B emergency diesel generator 24-hour run, on August 7, 2023
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
- (1) PT/0/A/4250/037, for Unit 1 main steam safety valve (1SV-20, 1SV-21, 1SV-22, 1SV-23, and 1SV-24) inservice testing, on September 13, 2023
Diverse and Flexible Coping Strategies (FLEX) Testing (IP Section 03.02) (1 Sample)
- (1) McGuire building #1 semi-annual testing of FLEX low pressure Hale Pump #3 and Caterpillar 600V Diesel 500 kW Generator, on September 18, 2023
71114.01 - Exercise Evaluation
Inspection Review (IP Section 02.01-02.11) (1 Sample)
- (1) The inspectors evaluated the biennial emergency plan exercise during the week of August 21, 2023. The exercise scenario began with a loss of coolant accident with an actuation of safety injection. This met the conditions for declaring an alert. Afterwards, radiation monitors increased above threshold levels. When a primary dose equivalent iodine sample confirmed cladding damage, a site area emergency was declared.
Finally, the containment equipment hatch failed and the conditions for a general emergency were met, allowing the offsite response organizations to demonstrate their ability to implement emergency actions.
71114.04 - Emergency Action Level and Emergency Plan Changes
Inspection Review (IP Section 02.01-02.03) (1 Sample)
- (1) The inspectors evaluated submitted emergency action level, emergency plan, and emergency plan implementing procedure changes during the week of August 21, 2023. This evaluation does not constitute NRC approval.
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated an emergency preparedness drill that consisted of a reactor coolant leak through a reactor coolant pump seal, followed by a steam generator tube rupture, followed by a faulted steam generator, on July 11, 2023.
71114.08 - Exercise Evaluation - Scenario Review
Inspection Review (IP Section 02.01 - 02.04) (1 Sample)
- (1) The inspectors reviewed and evaluated in-office, the proposed scenario for the biennial emergency plan exercise prior to the day of the exercise.
RADIATION SAFETY
71124.01 - Radiological Hazard Assessment and Exposure Controls
Radiological Hazard Assessment (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated how the licensee identifies the magnitude and extent of radiation levels and the concentrations and quantities of radioactive materials and how the licensee assesses radiological hazards.
Instructions to Workers (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated how the licensee instructs workers on plant-related radiological hazards and the radiation protection requirements intended to protect workers from those hazards.
Contamination and Radioactive Material Control (IP Section 03.03) (2 Samples)
The inspectors observed/evaluated the following licensee processes for monitoring and controlling contamination and radioactive material:
- (1) Control of non-fuel items in the Unit 1 spent fuel pool
- (2) Workers exiting the radiologically controlled area during the Unit 1 refueling outage (M1R29)
Radiological Hazards Control and Work Coverage (IP Section 03.04) (3 Samples)
The inspectors evaluated the licensee's control of radiological hazards for the following radiological work:
- (1) Unit 1 reactor vessel head peening
- (2) Unit 1 reactor vessel head non-destructive examination (3)1NV-156 relief valve replacement High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (4 Samples)
The inspectors evaluated licensee controls of the following high radiation areas and very high radiation areas:
- (1) Unit 1 reactor vessel head stand
- (2) Spent fuel pool cooling demineralizer room
- (3) Radwaste transfer pump evaporator concentrate storage tank
- (4) Spent resin storage tank room Radiation Worker Performance and Radiation Protection Technician Proficiency (IP Section 03.06) (1 Sample)
- (1) The inspectors evaluated radiation worker and radiation protection technician performance as it pertains to radiation protection requirements.
71124.08 - Radioactive Solid Waste Processing & Radioactive Material Handling, Storage, &
Transportation
Radioactive Material Storage (IP Section 03.01)
The inspectors evaluated the licensees performance in controlling, labeling and securing the following radioactive materials areas:
- (1) B-25 storage building (stalog)
- (2) Unit 1 mini dog lot #1, Unit 1 mini dog lot #2, and Unit 2 mini dog lot
- (3) Warehouse 7, warehouse 1, and outside scaffold sealand containers
Radioactive Waste System Walkdown (IP Section 03.02) (3 Samples)
The inspectors walked down the following accessible portions of the solid radioactive waste systems and evaluated system configuration and functionality:
- (1) Auxiliary building, 716 elevation-Liquid Waste Recycle System instrument gauges and controls
- (2) Solidification building, waste management processing demineralizer area, guard shield wall area, and truck bay area
- (3) Auxiliary building, 750 elevation-room 818C filter packing room, room 818A
Waste Characterization and Classification (IP Section 03.03) (3 Samples)
The inspectors evaluated the following characterization and classification of radioactive waste:
- (1) Radioactive shipment record (RSR) McGuire Nuclear Station (MNS) 23-0003, LSA-1 dry active waster (DAW) shipment
Shipping Records (IP Section 03.05) (5 Samples)
The inspectors evaluated the following non-excepted radioactive material shipments through a record review:
- (1) RSR MNS 23-0011, Type A container (equipment returned)
- (2) RSR MNS 23-0012, Type A container (equipment returned)
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS08: Heat Removal Systems (IP Section 02.07)===
- (1) Unit 1 (July 1, 2022, through June 30, 2023)
- (2) Unit 2 (July 1, 2022, through June 30, 2023)
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
- (1) Unit 1 (July 1, 2022, through June 30, 2023)
- (2) Unit 2 (July 1, 2022, through June 30, 2023)
MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)
- (1) Unit 1 (July 1, 2022, through June 30, 2023)
- (2) Unit 2 (July 1, 2022, through June 30, 2023)
OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)
- (1) February 1, 2022, through September 29, 2023 PR01: Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual Radiological Effluent Occurrences (RETS/ODCM) Radiological Effluent Occurrences Sample (IP Section 02.16) (1 Sample)
- (1) February 1, 2022, through September 4, 2023
EP01: Drill/Exercise Performance (DEP) Sample (IP Section 02.12) (1 Sample)
- (1) Drill & Exercise Performance for the period July 1, 2022, through June 30, 2023 EP02: Emergency Response Organization (ERO) Drill Participation (IP Section 02.13) (1 Sample)
- (1) Emergency response organization drill participation for the period July 1, 2022, through June 30, 2023 EP03: Alert And Notification System (ANS) Reliability Sample (IP Section 02.14) (1 Sample)
- (1) Alert and notification system reliability for the period July 1, 2022, through June 30, 2023
71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (1) NCR 02430524, Unit 1 loop D steam generator power operated relief valve, 1SV-1AB, failed valve stroke timing test, on August 24, 2023
- (2) NCR 02482758, gas detected during periodic venting of Unit 2 residual head removal to reactor water storage tank high point vent, 2ND-88, on September 28, 2023
- (3) NCR 02463199, Unit 2 refueling outage (M2R28) containment closure coordinator incomplete qualifications, on September 28, 2023
71153 - Follow Up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)
The inspectors evaluated the following licensee event report (LER):
- (1) LER 05000370/2023-001-00, McGuire Nuclear Station, Unit 2, Manual Actuation of the Unit 2 Motor Driven Auxiliary Feedwater Pumps (ADAMS Accession No. ML23151A370). The inspectors determined that it was not reasonable to foresee or correct the cause discussed in the LER, therefore no performance deficiency was identified. The inspectors did not identify a violation of NRC requirements.
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL
===60853 - Onsite Fabrication of Components and Construction 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 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. 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.
Onsite Fabrication of Components and Construction of an Independent Spent Fuel Storage Installation===
- (1) On April 10, 2023, to August 16, 2023, the inspector conducted a review of licensee and vendor activities in preparation for the construction of a concrete storage pad.
The inspectors verified that activities related to the ISFSI have been properly incorporated into the existing licensee programs by reviewing the following activities:
1. ISFSI pad design: The inspector verified that the licensee completed
evaluations which establish that the ISFSI storage pads and areas have been designed to adequately support the static and dynamic loads of the stored dry storage systems (DSS), considering potential amplification of earthquakes through soil-structure interaction, and soil liquefaction potential or other soil instability due to vibratory ground motion.
2. ISFSI pad construction: The inspector verified the ISFSI storage pad was
constructed in accordance with the DSS Certificate of Compliance and reviewed licensee controls that ensured no adverse impact to site operations or technical specifications by performing the following activities:
a.
The inspector walked down the construction area of the ISFSI pad to verify the formwork and rebar placement complied to licensee-approved drawings, specifications, b.
The inspectors observed the placement of the ISFSI slab, and observed tests for concrete slump, air content, temperature measurements, and the collection/preparation of cylinder samples for compression tests, to verify that the work was implemented in accordance with the approved specifications and procedures, c.
The inspector verified that the pad was being finished according to approved specifications and code requirements, d.
Following completion of the 7-day and 28-day compression tests by the independent laboratory, the inspector reviewed the results to verify that the acceptance criteria were met.
INSPECTION RESULTS
Failure to Implement Design Change Measures on Current Transformer Resulted in Unit 2 Turbine Runback Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05000370/2023003-01 Open/Closed None (NPP)71111.12 A self-revealed Green finding was identified when the licensee failed to meet licensee procedure EDM-101, Engineering Directive Manual-101, Engineering Calculations/
Analyses, Revision 15, which required the licensee to identify any special functional or physical interface requirements for systems or equipment affected by an engineering change.
Specifically, the licensee did not identify the impact on the current transformer mounting requirements associated with an engineering change to remove the shim material. The improper mounting of the current transformer resulted in a turbine runback.
Description:
On April 6, 2023, during Unit 2 reactor power ascension following a refueling outage, Unit 2 experienced a turbine runback to 55 percent RTP from 97 percent RTP due to a 2B busline lockout. This resulted in the loss of the 2B main step-up transformer. The direct cause for the event was attributed to the shifting and grounding of a current transformer, associated with the electrical distribution protective relaying circuit, in the 2B generator circuit breaker (GCB) Z-phase cubicle. The shifting of the transformer caused arcing from the current transformer to structural components within the breaker cubicle. This actuated the protective relaying circuit to isolate the respective electrical boundary by opening the 2B GCB and the downstream switchyard breakers. This led to the loss of the 2B main step-up transformer and the turbine runback.
The licensees causal investigation determined that modifications implemented for the current transformer did not prevent it from loosening and shifting into the position that resulted in the turbine runback. As originally installed, a shim material was between the current transformer and its associated mounting brackets. The licensee performed reoccurring inspections and replacement due to degradation of the shim material over time. In 2011, engineering change 105620 was developed to remove the shim material for the Units 1 and 2 current transformers located inside the GCB cubicles and substitute it with a small air gap to accommodate thermal expansion. The engineering change was implemented in 2013 for the current transformer within the 2B GCB Z-phase cubicle.
EDM-101, Revision 15, which was the effective procedure utilized during the engineering change in 2011, stated the following under question 6 of Table A-1, Electrical Design Input Checklist: Describe any special functional or physical interface requirements for systems or equipment affected by this change (e.g., non-standard power supply requirements, special mounting/orientation requirements). During the modification process, the licensee failed to assess the function the shim material served in holding the current transformer in place by static friction against the forces applied by mechanical shock in the breaker. Also, the licensee did not identify a need to periodically inspect the modified mounting hardware for the current transformer or modify preventive maintenance strategies to re-validate the size of the current transformer air gap after initial installation.
Corrective Actions: The licensee took actions to structurally secure the affected current transformer within the mounting brackets. Additional actions were taken to inspect the remaining current transformers associated with the 2B busline prior to returning Unit 2 to full power. The licensee inspected the current transformers associated with the 1A and 1B buslines on Unit 1 during the next Unit 1 refueling outage and determined that those current transformers were properly secured within the mounting brackets and contained a sufficient air gap. The licensee also conducted an extent of condition review to include other current transformers and circuits with protective relays and determined this issue to only affect the current transformers associated with the generator circuit breakers.
Corrective Action References: NCR 02468097
Performance Assessment:
Performance Deficiency: The licensee's failure to implement licensee procedure EDM-101, Engineering Directives Manual-101, Engineering Calculations/Analyses, Revision 15 for engineering change 105620 was a performance deficiency. Licensee procedure EDM-101 required the licensee to identify any special functional or physical interface requirements for systems or equipment affected by an engineering change. Specifically, the licensee did not identify the impact on the current transformer mounting requirements associated with an engineering change to remove the shim material. The improper mounting of the current transformer resulted in a turbine runback.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the plant modification implemented in 2013 to the current transformer in 2B GCB Z-phase cubicle led to a Unit 2 turbine runback, which upset plant stability by rapidly reducing reactor power to 55 percent RTP from 97 percent RTP.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Exhibit 1 - Initiating Events Screening Questions, the inspectors determined the finding to be of very low safety significance (Green) because all screening questions were answered no.
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:
Inspectors did not identify a violation of regulatory requirements associated with this finding.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On August 16, 2023, the inspectors presented the construction of an ISFSI inspection results to Edward Pigott and other members of the licensee staff.
- On August 24, 2023, the inspectors presented the emergency preparedness exercise inspection results to Edward Pigott and other members of the licensee staff.
- On September 28, 2023, the inspectors presented the radiation protection occupational radiation safety and transportation baseline inspection results to Edward Pigott and other members of the licensee staff.
- On October 18, 2023, the inspectors presented the integrated inspection results to Edward Pigott and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
RP/0/B/5700/027
Severe Weather Preparation
2143
M/CN, CGI, PQL2, Various, Hose, Aeroquip, JAS/MTB
Engineering
Changes
410758
M/CN, CGI, PQL2, Various, Hose, Aeroquip, JAS/MTB
Miscellaneous
254069
QC Inspection Report & Commercial Grade Dedication -
Test Data Sheet: Hose, Diesel, Engine, 58"
2/03/2020
20.00-00-0005
Reverse Engineering Evaluation: Aeroquip Fuel and Oil
Hoses for MNS Diesels
MCM 1301.00-
0077.001
Diesel Gen Engine Parts Manual
Procedures
MCS-1301.00-00-
0007
Nordberg Diesel Replacement Parts
Miscellaneous
Operational Risk Mitigation Plan - 1BD Power Supply Failure
AD-WC-ALL-0240
On-line Risk Management Process
CSD-WC-MNS-
240-00
McGuire Nuclear Station PRA: ERAT Guidance
Procedures
IP/0/B/3211/001B
Troubleshooting and Replacing Control Rod System Logic
and Power Cabinet Power Supplies
Work Orders
20612833
Corrective Action
Documents
Nuclear Condition
Reports
2462174, 02464821, 02465241
MCM 1346.05-
0136.001
High Range Gamma Radiation Monitoring System, OM
Manual
Corrective Action
Documents
Resulting from
Inspection
Work Requests
254276
252570
HP/0/B/1003/008
Determination of Radiation Monitor Setpoints (EMFs)
HP/0/B/1009/026A
EMF Alarm/Unusual Event Response
Procedures
PT/1/A/4600/003D
Monthly Surveillance Items
07/24/2023
Work Orders
Work Request 246243, 20249180
Corrective Action
Documents
Nuclear Condition
Reports
2478802, 02479021
AD-OP-ALL-0204
Plant Status Control
Procedures
OP/2/A/6350/002
Operation of the Chemical Volume and Control System
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
PT/1/A/4150/001B
Reactor Coolant Leakage Calculation
105
PT/1/A/4200/028A
Trian A Slave Relay Test
2
PT/2/A/4350/002A
Diesel Generator 2A Operability Test
23
Work Orders
20512778, 20568436, 20562207, 20512778
Calculations
Dose Assessment
[Drill]
Containment Leakage / Failure
08/22/2023
Miscellaneous
Emergency
Notification Form
Drill Messages 1 through 9
08/22/2023
AD-EP-ALL-0101
Emergency Classification
AD-EP-ALL-0103
Activation and Operation of the Emergency Operations
Facility
AD-EP-ALL-0109
Offsite Protective Action Recommendations
AD-EP-ALL-0202
Emergency Response Offsite Dose Assessment
AD-EP-ALL-0204
Distribution of Potassium Iodide Tablets in the Event of a
Radioiodine Release
AD-EP-ALL-0304
State and County Notifications
AD-EP-ALL-0803
Evaluation and Critique of Drills and Exercises
AD-EP-MNS-0203
MNS Site Specific Field Monitoring
CSD-EP-ALL-
202-01
URI Manual
CSD-EP-MNS-
0101-02
McGuire EAL Wallchart
Procedures
EP-MNS-EPLAN-
ANNEX
Duke Energy McGuire Emergency Plan Annex
EREG# 02463164
CFR 50.54(q) Review Form for EP-ALL-EPLAN, Rev. 4
03/22/2023
EREG# 02448772
CFR 50.54(q) Review Form for EAL Technical Basis
Document, Rev. 3
01/30/2023
EREG# 02473864
CFR 50.54(q) Review Form for AD-EP-ALL-0305, Fleet
Emergency Preparedness (EP) Alert and Notification System
05/25/2023
Miscellaneous
EREG# 2476177
CFR 50.54(q) Review Form for AD-EP-ALL-0305, Fleet
Emergency Preparedness (EP) Alert and Notification System
Procedures
AD-EP-ALL-0305
Fleet Emergency Preparedness (EP) Alert and Notification
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
AD-EP-ALL-0305
Fleet Emergency Preparedness (EP) Alert and Notification
CSD-EP-MNS-
0101-01
EAL Technical Basis Document
Duke Energy Common Emergency Plan
Miscellaneous
MNS Drill 23-02
07/17/2023
Corrective Action
Documents
Resulting from
Inspection
Nuclear Condition
Report
2488630
Engineering
Evaluations
AD-RP-ALL-2015
Alpha Radiation Characterization
06/26/23
Procedures
AD-RP-ALL-2014
Work in Alpha Environments
AD-RP-ALL-0002
Radiation and Contamination Surveys
MNS-M-
220420-11
Maintenance torque of 1NV-156 valve
04/20/2022
MNS-M-
230927-17
1NV-156 decon job coverage
09/27/2023
Radiation
Surveys
MNS-M-
230927-5
Removal of 1NV-156 valve
09/27/2023
Corrective Action
Documents
Nuclear Condition
Report
2458616
Corrective Action
Documents
Resulting from
Inspection
Nuclear Condition
Report
2488645
Shipping Records
RSR 22-0019, RSR 23-0003, RSR 23-0004,
RSR-MNS-23-0011, RSR-MNS-23-0012, RSR 23-0016
Nuclear Condition
Reports
269344, 02268288, 02268497, 02476484, 02446466,
2463199
Corrective Action
Documents
Procedure
Revision
Requests
2466357, 02464747, 02466358, 02464746, 02469308,
2460193
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
OP/2/A/4200/019
ECCS Pumps and Piping Vent
Procedures
PT/1/A/4200/002C
Containment Closure
Work Orders
Work Requests
20323992, 20430314, 20597177, 20540758, 20184464,
20186651, 20227933, 20227926