IR 05000324/2023004
| ML24036A133 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 02/06/2024 |
| From: | Matthew Fannon NRC/RGN-II/DRP/RPB4 |
| To: | Krakuszeski J Duke Energy Progress |
| References | |
| IR 2023004 | |
| Download: ML24036A133 (21) | |
Text
SUBJECT:
BRUNSWICK STEAM ELECTRIC PLANT - INTEGRATED INSPECTION REPORT 05000324/2023004 AND 05000325/2023004
Dear John A. Krakuszeski:
On December 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Brunswick Steam Electric Plant. On January 31, 2024, 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.
Three findings of very low safety significance (Green) are documented in this report. Three of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the significance or severity of the violations 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 Brunswick Steam Electric Plant.
If you disagree with a cross-cutting aspect assignment 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 Brunswick Steam Electric Plant.
February 6, 2024 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, Matthew S. Fannon, Chief Reactor Projects Branch 4 Division of Reactor Projects Docket Nos. 05000324 and 05000325 License Nos. DPR-62 and DPR-71
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000324 and 05000325
License Numbers:
Report Numbers:
05000324/2023004 and 05000325/2023004
Enterprise Identifier:
I-2023-004-0014
Licensee:
Duke Energy Progress, LLC
Facility:
Brunswick Steam Electric Plant
Location:
Southport, NC
Inspection Dates:
October 01, 2023, to December 31, 2023
Inspectors:
B. Bowker, Reactor Inspector
P. Cooper, Senior Reactor Inspector
C. Curran, Resident Inspector
J. Rivera, Health Physicist
A. Rosebrook, Senior Reactor Analyst
M. Schwieg, Senior Reactor Inspector
G. Smith, Senior Resident Inspector
J. Vasquez, Reactor Inspector
A. Wilson, Senior Project Engineer
Approved By:
Matthew S. Fannon, Chief
Reactor Projects Branch 4
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees
performance by conducting an integrated inspection at Brunswick Steam Electric Plant, 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 Broken Supports on the Conventional Service Water Headers
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
NCV 05000325,05000324/2023004-01
Open/Closed
[H.8] -
Procedure
Adherence
71003
The NRC identified a Green finding and associated non-cited violation (NCV) of Title 10 of the
Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion V, "Instructions,
Procedures, and Drawings," for the licensee's failure to identify broken piping supports as
required by licensee procedures AD-EG-ALL-1213, System Walkdown, and AD-EG-BNP-
1213, BNP Specific Requirements for System Walkdowns.
Failure to Evaluate Degraded Crane Rail Assembly of the Intake Structure Gantry Crane
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Green
NCV 05000325,05000324/2023004-02
Open/Closed
[P.2] -
Evaluation
71003
The NRC identified a Green finding and associated NCV of 10 CFR Part 50, Appendix B,
Criterion V, "Instructions, Procedures, and Drawings," for the licensee's failure to evaluate a
degraded condition as required by procedure AD-EG-BNP-1214, Condition Monitoring of
Structures. Specifically, the licensee failed to ensure the loss of effective metal thickness due
to corrosion of the crane rail, crane rail clips, and associated fasteners would not lead to a
structural failure of the intake structure gantry crane that could impact the Class I Service
Water Intake Structure.
Failure to Properly Perform a Cable Splice Results in a Failure of the Unit 2 'A' Core Spray
Pump Cable
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open/Closed
[H.5] - Work
Management
A self-revealed Green finding and associated NCV of technical specification 5.4.1.a, was
identified for the licensees failure to maintain adequate procedural guidance in maintenance
procedures 0SPP-CBL011, Splicing of Wires and Cables Using Tape, Rev. 11, and 0SPP-
CBL011, Splicing of Wires and Cables Without Tape, Rev. 15, regarding the splicing of
safety-related cables.
Additional Tracking Items
None.
PLANT STATUS
Unit 1 began the period at 100 percent rated thermal power (RTP) and operated there until
October 8, 2023, when the control room operators were forced to reduce power to 52 percent
RTP due to a circulating water leak located in the condenser bay. The forced down power was
required in order to stop the affected circulating water pumps and isolate the leak. Following
repairs to the circulating water system, the unit was restored to full power operation on October
11 where it continued to operate until November 10 when power was reduced to 70 percent
RTP to perform a control rod sequence exchange and turbine valve testing. Following the valve
testing, sequence exchange, and two control rod improvements, the unit was restored to full
RTP on November 16, where it continued to operate until December 15 when power was
reduced to 76 percent RTP to perform a control rod improvement. Following the rod
improvement, the unit was restored to full RTP on December 16, where it continued to operate
for the remainder of the inspection period.
Unit 2 began the period at 100 percent RTP and operated there until November 29, 2023, when
power was reduced to 53 percent for control rod sequence exchange, turbine valve testing, and
condenser water-box patch hardening. Following the sequence exchange, valve testing, water-
box maintenance, and two follow on control rod improvements, the unit was restored to full RTP
on December 5, where it continued to operate 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 DProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 2515,</br></br>Appendix D" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., 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) (2 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following
systems/trains:
(1)
Emergency diesel generator (EDG)-3 while EDG-4 was out-of-service for planned
maintenance on October 11, 2023
(2)
All four EDGs following the receipt of an unexpected automatic start signal on
December 28, 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)
Service water building on October 24, 2023
(2)
Unit 1 reactor building 80' and 117' elevation on October 25, 2023
(3)
Unit 1 reactor building -17' elevation on October 26, 2023
(4)
Unit 1 and Unit 2 turbine building 20 elevation (non-steam-affected areas) on
November 12, 2023
71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance
Requalification Examination Results (IP Section 03.03) (1 Sample)
The licensee completed the annual requalification operating examinations and biennial
written examinations required to be administered to all licensed operators in accordance
with 10 CFR 55.59(a)(2), "Requalification Requirements," of the NRC's "Operator's
Licenses." The inspector performed an in-office review of the overall pass/fail results of the
individual operating examinations, the crew simulator operating examinations, and the
biennial written examinations in accordance with IP 71111.11, "Licensed Operator
Requalification Program and Licensed Operator Performance." These results were
compared to the thresholds established in Section 3.03, "Requalification Examination
Results," of IP 71111.11.
(1)
The inspectors reviewed and evaluated the licensed operator examination failure
rates for the requalification annual operating exam completed on September 28,
2023, and the biennial written examinations completed on September 26, 2023.
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 a Unit 1 down power to 70 percent RTP for control rod sequence
exchange, condenser water-box leak repairs, and turbine valve testing on November
10, 2023.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (4 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)
Re-evaluate EDG-3 unavailability performance monitoring threshold (NCR 2479254)
(2)
Unit 2 battery maintenance rule unavailability exceeded (NCR 2464008)
(3)
Main control room HVAC unit 1D condensing unit fan failure (NCR 2458527)
(4)
Plant sump pump level switch failures (NCR 2476097)
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (1 Sample)
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)
EDG-4 outage from October 8 through October 19, 2023, which involved a risk
informed completion time analysis that exceeded the normal limiting condition of
operation time of 7 days
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the
following operability determinations and functionality assessments:
(1)
EDG-4 common cause failure review (NCR 2490446)
(2)
Local power range monitor instrument failure (NCR 2485451)
(3)
Past operability determination regarding the Unit 2 A core spray pump cable failure
(NCR 2462552)
(4)
Broken bolting on nuclear service water header pipe supports (NCR 2495136)
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)
EDG-3 Engine Overspeed Trip Upgrade (Engineering Change (EC) 421556)
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) (10 Samples)
(1)
0PT-15.7, Standby Gas Treatment System Operability Test, Rev. 47, following 8-
year limitorque preventive maintenance on Unit 8 A standby gas treatment fan inlet
damper (2-VA-2C-RB) in accordance with (IAW) work order (WO) 20568033
(2)
0PT-12.2A, No. 1 Diesel Generator Monthly Load Test, Rev. 125, following
replacement of the EDG-1 auto setpoint reference adjustor, RA-70 IAW WO 20619222
(3)
0PT-12.2B, No. 2 Diesel Generator Monthly Load Test, Rev. 125, following
performance of EDG-2 logic testing on September 26, 2023
(4)
0PT-12.2D, No. 4 Diesel Generator Monthly Load Test, Rev. 127, following 480-volt
circuit breaker preventive maintenance activities IAW WO 20198287, 20198291, and
20198288
(5)
0SPP-HYDRO501, Functional Pressure Testing, Rev. 32, following replacement of
the 2A seal coolers on 2A residual heat removal (RHR) IAW WO 20346162-03
(6)
0PT-08.2.2C, LPCI/RHR System Operability Test - Loop A, Rev. 100, following 2A
RHR outage breaker work PMT on October 30, 2023, IAW WO 20497685 01
(7)
0SPP-HYDRO501, Functional Pressure Testing, Rev. 32, following replacement of
the 2C seal coolers on 2A RHR IAW WO 20346119-03
(8)
0PT-12.2D, No. 4 Diesel Generator Monthly Load Test, Rev. 127, following the
replacement of O-rings on power packs 1L, 4L, 5R, 6R, 7L, 8R, IAW WO 20609324
(9)
0OP-39, "Diesel Generator Operating Procedure," Rev. 202, following replacement of
the EDG-1 overspeed time delay relays, 2-DG1-DA and 2-DG1-DB, IAW WO 20566369
(10)
2SP-EC421556-001, "Post-Modification Testing for DG3 Overspeed System
Upgrade," Rev. 0, following improvements made to EDG-3 overspeed trip system
IAW EC 421556 and WO 20567293
Surveillance Testing (IP Section 03.01) (5 Samples)
(1)
0PT-01.9, LPRM Calibration, Rev. 49, IAW WO 20597240
(2)
1MST-DG22R, "DG-2 Trip Bypass Logic Test," Rev. 27, IAW WO 20527700
(3)
0PT-12.2.1B, ECCS D/G #2 Logic Test, Rev. 9, completed on November 27, 2023
(4)
0MST-RHR23Q, RHR-LPCI ADS CS LL3, HPCI RCIC LL2 Div II TR Unit Chan Cal,
Rev. 10, completed on December 14, 2023
(5)
2MST-PCIS29R, PCIS Reactor Water LL2 and LL3 DIV II Inst Channel Calibration
and Functional Test, Rev. 18, completed on December 14, 2023
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
(1)
0PT-10.1.8, "RCIC System Valve Operability Test," Rev. 47, performed on November
12, 2023
Diverse and Flexible Coping Strategies (FLEX) Testing (IP Section 03.02) (1 Sample)
(1)
0PT-12.27, Flex Diesel Generator 1 and 2 Test Procedure, Rev. 5, following a flex
diesel run on November 3, 2023
OTHER ACTIVITIES - BASELINE
71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
MS07: High Pressure Injection Systems (IP Section 02.06) (2 Samples)
(1)
Unit 1 (October 1, 2022, through September 30, 2023)
(2)
Unit 2 (October 1, 2022, through September 30, 2023)
MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)
(1)
Unit 1 (October 1, 2022, through September 30, 2023)
(2)
Unit 2 (October 1, 2022, through September 30, 2023)
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
(1)
Unit 1 (October 1, 2022, through September 30, 2023)
(2)
Unit 2 (October 1, 2022, through September 30, 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)
April 1, 2022, through March 31, 2023
71152A - Annual Follow-up Problem Identification and Resolution
Annual Follow-up of Selected Issues (Section 03.03) (1 Sample)
The inspectors reviewed the licensees implementation of its corrective action program
related to the following issue:
(1)
Ground on the 2A Core Spray Pump (NCR 2462552)
71152S - Semiannual Trend Problem Identification and Resolution
Semiannual Trend Review (Section 03.02) (1 Sample)
(1)
The inspectors reviewed the licensees corrective action program for potential
adverse trends in operations and maintenance that might be indicative of a more
significant safety issue.
71153 - Follow Up of Events and Notices of Enforcement Discretion
Event Follow up (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated the Brunswick site's emergency declaration of a Notice of
Unusual Event (NOUE) and the licensees response on October 15, 2023. The NOUE
was declared as a result of a fire and subsequent halon discharge in the EDG
basement. The licensee reported this event to the headquarters operation officer
(HOO) as emergency notification #56797 pursuant to 10 CFR 50.72(a)(1).
Personnel Performance (IP Section 03.03) (1 Sample)
(1)
The inspectors evaluated the Brunswick site's response to an unexpected automatic
start of all four EDGs due to a failed under voltage relay on December 28, 2023. The
licensee deemed this actuation to be invalid and will report the event to the NRC
HOO within 60 days pursuant to 10 CFR 50.73(a)(1).
OTHER ACTIVITIES - TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL
71003 - Post-Approval Site Inspection for License Renewal
The NRC continued monitoring licensees performance by conducting a Post-Approval Site
Inspection for License Renewal - Phase 4 in accordance with the license renewal inspection
program (LRIP). Per IMC 2516, the LRIP is the process used by NRC staff to verify the
adequacy of aging management programs (AMPs) and other activities associated with an
applicants request to renew an operating license of a commercial nuclear power plant beyond
the initial licensing period under 10 CFR Part 54, Requirements for the Renewal of Operating
Licenses for Nuclear Power Plants.
The inspectors reviewed the licensees implementation of the AMPs shown below by selecting a
sample of SSCs within the scope of the respective AMPs. The inspectors performed the
following activities, as applicable to each SSC, to determine that there is a reasonable
assurance that the effects of aging are being adequately managed: walked down all accessible
SSCs to observe their general condition and identify any signs of aging related degradation;
interviewed plant personnel; reviewed completed work orders; reviewed applicable monitoring
and trending data; and reviewed the acceptability of inspection and test results. For each AMP
shown below, the inspectors also reviewed a sample of aging related issues entered into the
licensees corrective action program to verify that age-related degradation is being identified at
an appropriate threshold and corrected.
Post-Approval Site Inspection for License Renewal (13 Samples)
(1)
ASME Section XI, Inservice Inspection, Subsection IWB, IWC, and IWD Program
(UFSAR Section 18.1.1)
Unit 1 - Reactor Head Closure studs, nuts, and washers
Unit 2 - Reactor Head Closure studs, nuts, and washers
(2)
Flow-Accelerated Corrosion Program (UFSAR Section 18.1.5)
Unit 1 - Two most recent FAC Program Post Outage Reports
Unit 2 - Two most recent FAC Program Post Outage Reports
(3)
Open-Cycle Cooling Water System Program (UFSAR Section 18.1.7)
RHR Heat Exchanger - PMID 45752-02
RHR Heat Exchanger - PMID 45753-03
Circulating Water Lubricating Water Strainer 1-SW-ST-2
EDG cooling water expansion joint - PMID 3306-01
(4)
Inspection of Overhead Heavy Loads and Light Load Handling System Program
(UFSAR Section 18.1.9)
Unit 1 and 2 Reactor Building Bridge Cranes
Unit 1 and 2 Refueling Platforms
Service Water Intake Structure Gantry Crane
(5)
Aboveground Carbon Steel Tanks Program (UFSAR Section 18.1.12)
Condensate Storage Tank
Fire Protection Storage Tank
(6)
Reactor Vessel Surveillance Program (UFSAR Section 18.1.14)
Unit 1 - Core Plate
Unit 2 - Top Guide
Unit 1 - Jet Pump Assembly
Unit 1 - Core Shroud
- Unit 2 - Core Spray Spargers
(7)
ASME Section XI, Subsection IWE Program (UFSAR Section 18.1.18)
Unit 1 - Drywell Liner Moisture Barrier
Unit 2 - Downcomer
Unit 1 - Personnel airlock
Unit 2 - Torus Liner
(8)
ASME Section XI, Subsection IWF Program (UFSAR Section 18.1.20)
Unit 1 Nuclear and Conventional Service Water headers piping supports EL-4
Unit 2 Nuclear and Conventional Service Water headers piping supports EL-4
(9)
10 CFR 50, Appendix J Program (UFSAR Section 18.1.21)
Unit 1 - 15 Year Containment Leak Rate Test
Unit 2 - 15 Year Containment Leak Rate Test
(10)
Structures Monitoring Program (UFSAR Section 18.1.23)
Reactor Building (Unit 1)
Fuel Pool Girder Tendon
Service Water Intake Structure
(11)
Inaccessible Medium Voltage Cables Not Subject to 10 CFR 50.49 Environment
Qualification Requirements Program (UFSAR Section 18.1.27)
2A Core Spray pump motor cables
2A Residual Heat Removal Service Water pump motor cables
(12)
Phase Bus Aging Management Program (UFSAR Section 18.1.33)
Unit 1 Non-Segregated Bus
Unit 2 Non-Segregated Bus
(13)
Cryofit Coupling Hydrogen Embrittlement Program (UFSAR 18.1.36)
50.59's for the FSAR changes
Metallurgical evaluations of the removed couplings (Reports 5960A and
5960B)
INSPECTION RESULTS
Failure to Identify Broken Supports on the Conventional Service Water Headers
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
NCV 05000325,05000324/2023004-01
Open/Closed
[H.8] -
Procedure
Adherence
71003
The NRC identified a Green finding and associated non-cited violation (NCV) of Title 10 of the
Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion V, "Instructions,
Procedures, and Drawings," for the licensee's failure to identify broken piping supports as
required by licensee procedures AD-EG-ALL-1213, System Walkdown, and AD-EG-BNP-
1213, BNP Specific Requirements for System Walkdowns.
Description: On November 16, 2023, the inspectors conducted a walkdown in the service
water building (SWB) to inspect the header piping supports. The inspectors identified two
broken bolts on pipe supports 1-SW-PS-2112-3 and 2-SW-PS-2112-3 and several other bolts
that were misaligned and had general corrosion. These supports act to restrain the
conventional service water (CSW) header.
The inspectors reviewed the system walkdowns guidance in the following procedures AD-EG-
ALL-1213, System Walkdown, and AD-EG-BNP-1213, BNP Specific Requirements for
System Walkdowns.
In AD-EG-ALL-1213, System Walkdown, Section 5.3, Step 5 requires any degraded
conditions observed in structures or components to be documented in the corrective action
program. In Section 14.0, Supports and Snubbers, it requires bolting to be checked for
tightness and be properly attached to the wall, floor, or component.
In AD-EG-BNP-1213, BNP Specific Requirements for System Walkdowns, Attachment 1
requires system walkdowns of the SWB to be performed on a quarterly frequency. In
Attachment 2, Walkdown Inspection Resource, Section 12 requires checks for adequate
bolting engagement and Section 14 requires checks for any slide plate interference or
misalignment. In Attachment 3, BNP Specific Requirements for System Walkdowns, Item 2
specifies the system walkdown inspection boundary to include component bolted connections
and the aging effects managed are loss of material due to general corrosion.
The inspectors concluded that given the procedural guidance for system walkdowns, the
SWB broken bolt supports should have been identified and documented during recent system
walkdowns.
The licensee issued a condition report and performed an immediate operability determination
for the CSW system. The licensee determined based on a reviewed of pipe stress and
support calculations, that the condition did not impact operability. Additionally, the broken
bolts were replaced per work orders.
The inspectors reviewed the operability determination and discussed the support calculations
with licensees civil engineers. The piping bolts mainly provided support for rotational loads
on the CSW header. With only one piping bolt failure, there was adequate margin available
with the remaining other piping bolt supports. The main horizontal and vertical piping loads
were being handled by the other supports in the room. As a result, the inspectors believe
there was still reasonable assurance in the past operability of the CSW system.
Corrective Actions: EC 423476 was performed to evaluate operability and the broken bolt
supports were replaced per WO 20634464 and WO 20634543.
Corrective Action References: NCR 02495136
Performance Assessment:
Performance Deficiency: The inspectors determined the failure to identify broken piping
supports during a systems walkdown in accordance with procedures AD-EG-ALL-1213
System Walkdown, and AD-EG-BNP-1213, BNP Specific Requirements for System
Walkdowns, was a performance deficiency.
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. The piping support bolts provide protection against seismic and
internal flooding events.
Significance: The inspectors assessed the significance of the finding using IMC 0609
Appendix AProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 0609</br></br>Appendix A" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., The Significance Determination Process (SDP) for Findings At-Power. The
inspectors assessed the significance of the violation through IMC 0609 Significance
Determination Process Exhibit 2, "Mitigating Systems," Section B, "External Event Mitigating
System," and determined the violation to be Green as it did not result in a loss or degradation
of equipment function specifically designed to mitigate a seismic, flooding, or severe weather
initiating event.
Cross-Cutting Aspect: H.8 - Procedure Adherence: Individuals follow processes, procedures,
and work instructions. There was sufficient procedural guidance for individuals conducting
system walkdown to identify and document the broken piping bolts.
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings,
requires, in part, that activities affecting quality shall be accomplished in accordance with
these instructions, procedures, or drawings.
Contrary to the above, until November 16, 2023, the licensee did not identify and correct the
broken piping supports on the CSW header as required by licensee procedures AD-EG-ALL-
1213, "System Walkdown," and AD-EG-BNP-1213, BNP Specific Requirements for System
Walkdowns.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with
Section 2.3.2 of the Enforcement Policy.
Failure to Evaluate Degraded Crane Rail Assembly of the Intake Structure Gantry Crane
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Green
NCV 05000325,05000324/2023004-02
Open/Closed
[P.2] -
Evaluation
71003
The NRC identified a Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion V, "Instructions, Procedures, and Drawings," for the licensee's
failure to evaluate a degraded condition as required by procedure AD-EG-BNP-1214,
Condition Monitoring of Structures. Specifically, the licensee failed to ensure the loss of
effective metal thickness due to corrosion of the crane rail, crane rail clips, and associated
fasteners would not lead to a structural failure of the intake structure gantry crane that could
impact the Class I Service Water Intake Structure.
Description: On November 14th, 2023, inspectors performed a walkdown of the intake
structure gantry crane to verify age-related degradation is being identified and corrected as
described in the Overhead Heavy Load and Light Load Handling Systems Program. During
the walkdown, the inspectors identified corrosion along the east crane rail assembly between
the intake canal and the intake cooling water pump traveling screens.
The Brunswick License Renewal Application (ADAMS Accession Number ML043060411)
Section 2.4.2.6 states that the Intake Structure Gantry Crane is in scope for License
Renewal, because it has the potential to impact the Class I Service Water Intake Structure
should a structural failure occur. The passive physical crane structures, such as the main
structural members, bridge, trolley, structural girders, rail system, and anchorage brackets,
are considered sub-components of the Intake Structure Gantry Crane.
Licensee procedure AD-EG-BNP-1214, Condition Monitoring of Structures, Attachment 1
requires that the extent of allowable corrosion should be based on the strength of the
remaining effective metal thickness or by direct measurement of remaining load capacity
(e.g., tensile testing of bolts), as compared to the design allowable values. Appropriate
means shall be used for verifying remaining wall thickness (e.g., ultrasonic testing, calipers,
micrometers, use of divers for remote underwater measurements, etc.).
The inspectors reviewed the licensee's engineering change package (EC 400847) and
identified that portions of the crane rail, rail baseplate, clips, studs, and nuts were replaced
during the gantry crane replacement project in 2016. Subsequently, per the licensees
corrective action document (AR 02173503) adverse conditions of the east rail assembly were
identified as early as 2017. Inspectors reviewed licensee work order (WO 10528656 03 dated
10/25/2022) and noted that the licensee identified deficiencies associated with delamination
and flowering corrosion, heavy corrosion with pitting, and coating loss. Additionally, the
licensee stated that the deficiencies were prevalent in many areas of the intake structure
gantry crane rail assembly and that the full extent of loss could not be determined. The
inspectors reviewed past inspection reports and documentation provided in response to NRC
requests for evaluation (NCR 02494890 and EC 423493) and identified that since 2017 the
remaining material thickness was not recorded and evaluation for the extent of allowable
corrosion as compared to design allowable values had not been performed.
On December 19, 2023, the licensee provided EC 423589 which documents measurements
of the remaining effective metal thickness of a representative sample of the rail clip studs and
nuts experiencing corrosion. This material loss was evaluated against design capacity, and
the licensee concluded that the rail clip assemblies have adequate material remaining to
perform as designed.
Corrective Actions: ECs 423493 and 423589 were performed to evaluate the condition of the
corroded crane rail assembly.
Corrective Action References: NCR 02494890
Performance Assessment:
Performance Deficiency: The inspectors determined that the failure to establish the extent of
allowable corrosion based on the strength of the remaining effective metal thickness as
required by licensee procedure AD-EG-BNP-1214, Condition Monitoring of Structures, was
a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor
because if left uncorrected, it would have the potential to lead to a more significant safety
concern. Specifically, continued degradation of the crane rail, crane rail clips, and association
fasteners could lead to a failure of the intake structure gantry crane which could impact the
Class I Service Water Intake Structure. In response to the identified concern, the licensee
measured the remaining material and performed an evaluation of the rail assembly and
determined that the sub-components could still perform their intended function in their current
state.
Significance: The inspectors assessed the significance of the finding using IMC 0609
Appendix AProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 0609</br></br>Appendix A" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., The Significance Determination Process (SDP) for Findings At-Power. Using
Exhibit 1 Initiating Events Screening Questions, Section C Support System Initiators, the
inspectors determined the violation to be Green because the degraded condition did not
result in an actual complete or partial loss of a support system, and it did not increase the
likelihood of a complete loss of a support system that would result in a plant trip.
Cross-Cutting Aspect: P.2 - Evaluation: The organization thoroughly evaluates issues to
ensure that resolutions address causes and extent of conditions commensurate with their
safety significance. Specifically, the licensee failed to perform an evaluation as required by
procedure AD-EG-BNP-1214, Condition Monitoring of Structures.
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings,
requires, in part, that activities affecting quality shall be accomplished in accordance with
documented instructions, procedures, or drawings of a type appropriate to the circumstances.
Licensee procedure AD-EG-BNP-1214, Condition Monitoring of Structures, Attachment 1
requires that the extent of allowable corrosion should be based on the strength of the
remaining effective metal thickness or by direct measurement of remaining load capacity
(e.g., tensile testing of bolts), as compared to the design allowable values. Appropriate
means shall be used for verifying remaining wall thickness (e.g., ultrasonic testing, calipers,
micrometers, use of divers for remote underwater measurements, etc.).
Contrary to the above, since 2017, the licensee failed to establish the extent of allowable
corrosion based on the strength of the remaining effective metal thickness. Specifically, the
licensee failed to ensure the loss of effective metal thickness due to corrosion of the crane
rail, crane rail clips, and associated fasteners would not lead to a structural failure of the
intake structure gantry crane that could impact the Class I Service Water Intake Structure.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with
Section 2.3.2 of the Enforcement Policy.
Failure to Properly Perform a Cable Splice Results in a Failure of the Unit 2 'A' Core Spray
Pump Cable
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open/Closed
[H.5] - Work
Management
A self-revealed Green finding and associated NCV of technical specification 5.4.1.a, was
identified for the licensees failure to maintain adequate procedural guidance in maintenance
procedures 0SPP-CBL011, Splicing of Wires and Cables Using Tape, Rev. 11, and 0SPP-
CBL011, Splicing of Wires and Cables Without Tape, Rev. 15, regarding the splicing of
safety-related cables.
Description: On February 27, 2023, while in Mode 5 during a refueling outage, operators
started the Unit 2 'A' core spray pump as a prerequisite to loss of offsite power
testing. Immediately following the pump start, the operators received multiple alarms that
indicated a ground fault on the E3 emergency bus was in progress. The operators then
immediately secured the 'A' core spray pump to investigate. Initial investigation indicated a
fault of the 'A' core spray pump cable as discovered by electricians who noted low cable
resistance on the 'A' core spray pump on the secondary side of the E3 bus. Subsequently,
electricians entered manhole 2-MH-2SW and noted a significant failure of the 'C' phase on
the 'A' core spray pump cable. The manhole splice is the junction point between the EDG
building (power source side) and the reactor building (load or pump side). The electricians
noted that a portion of the cable's insulation was significantly burned/vaporized due to some
sort of fault. The insulation jacket appeared to fail in a region that was previously covered by
shrink wrap from a previous cable splice in 2011.
A review of the history of the Unit 2 'A' core spray pump cable revealed that the original cable
and splice was installed around 1974. The original splice in the manhole was of the metal
canister type. In 2011, the cable failed Tan-Delta (insulation test) testing which was being
performed every six years. The metal canister splice was deemed the point of failure and was
then replaced with two separate Raychem (heat shrink) splices. Additionally, a new 500 MCM
shielded cable jumper was installed. The cable was then placed in service following
satisfactory Tan-Delta testing results. Six years later, in 2017, the subsequent Tan-Delta
testing revealed cable insulation degradation. The cable was retested in 2018 and showed
continued degradation. Repairs were then planned for 2019. In 2019, two separate cable
repairs were made to the jumper installed in 2011. Following the 2019 repairs, satisfactory
Tan-Delta testing results were achieved the cable was placed in service again. The next Tan-
Delta testing was planned for 2025 (six years later) until the failure occurred in 2023.
Following the cable repairs from the February 27, 2023, failure, the licensee commenced a
detailed causal analysis of the failed cable. The point of failure was noted to be on a splice
that was installed during the original repair in 2011. Additionally, the failed cable section was
removed and sent to a specialized lab, Safe-Labs, for further analysis. Safe-Labs ultimately
concluded that water migrated under the heat shrink tubing and caused severe corrosion of
the copper shielding mesh, degradation of the outer heat shrink, and water treeing. Water
treeing is a degradation mechanism in a cable's insulation, where dense networks of micro-
voids and channels filled with water are formed. Based on discussions with the cable splice
vendor, Raychem, heat shrink installed in a cable splice with existing degraded cable
insulation can lead to a premature failure of the splice due to water intrusion. The causal
analysis team ultimately concluded that the cause of the event was due to a lack of adequate
work instructions for the cable splice performed in 2011. Specifically, the instructions
contained in in 0SPP-CBL011, Splicing of Wires and Cables Using Tape, Rev. 11, and
0SPP-CBL011, Splicing of Wires and Cables Without Tape, Rev. 15, did not (and do not
currently) state any prerequisites for the condition of the cable.
Corrective Actions: The immediate corrective action was to repair the failed section of cable
using a newly installed splice. A causal analysis of the cable failure included an extent of
cause analysis. The extent of cause noted two splices similar to the one made on the Unit 2
'A' core spray pump cable. These splices included the Unit 1 'A' core spray pump cable and
the Unit 2 'A' residual heat removal pump cable. Ultimately, the extent of cause provided
corrective actions to increase the cable testing (Tan-Delta) frequency from six years to three
years for the above three cables in order to more rapidly detect future cable failures.
Additionally, the licensee has committed to revise maintenance procedures 0SPP-CBL011,
Splicing of Wires and Cables Using Tape, and 0SPP-CBL011, Splicing of Wires and
Cables Without Tape, to include guidance on requesting an engineering evaluation if visible
cable degradation is present when attempting to perform a cable splice.
Corrective Action References: NCR 2462552, "Ground on 2A Core Spray Pump," February
27, 2023
Performance Assessment:
Performance Deficiency: The licensee's failure to maintain adequate instructions pertaining to
maintenance of safety-related cables as required by technical specifications was determined
to be a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor
because it was associated with the Equipment Performance 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. Specifically, heat shrink tubing (splice) was installed over a
degraded cable jacket that allowed water intrusion and ultimately a cable failure, which led to
the reduction in reliability of the Unit 2 'A' core spray pump.
Significance: A regional Senior Reactor Analyst (SRA) performed a detailed risk assessment
for the condition. The SRA modeled the condition using SAPHIRE 8 Version 8.2.9 and the
Brunswick Unit 2 SPAR model version 8.82 dated 8/30/2023. The SRA modeled the condition
by setting LCS-MDP-FR-2A LCS MDP 2A FAILS TO RUN and LCS-MDP-FS-2A LCS MDP
2A FAILS TO START to True. The reason for the failure of the insulation in this connection
was water intrusion into the area of the splice, and the splice was installed in 2011. The
reason for water intrusion into the heat shrink splice was that the sealing interfaces between
the outer heat shrink covering and the cable outer jacket did not remain watertight because
the outer heat shrink splice covering was installed over a degraded outer jacket which was
also performed in 2011. The manway is in a wet area and was found flooded on occasion
since 2011. Therefore, the SRA conservatively set the exposure period to be one year in
order to bound the condition. The dominant accident sequence was a loss of an AC
switchboard, failure of the condensate and control rod drive systems, failure of normal and
alternate low pressure injection, and failure of suppression pool cooling. The change in core
damage frequency was less than 1 E-6 event/yr. which corresponds to a finding of very low
safety significance (Green).
Cross-Cutting Aspect: H.5 - Work Management: The organization implements a process of
planning, controlling, and executing work activities such that nuclear safety is the overriding
priority. The work process includes the identification and management of risk commensurate
to the work and the need for coordination with different groups or job activities. Although the
original splice was made in 2011, the inspectors deemed this performance deficiency to be
indicative of current plant performance because the maintenance procedure did not and does
not currently address the existing cable condition when performing a splice. This inadequate
procedure could lead to future cable failures if left uncorrected.
Enforcement:
Violation: Technical Specification 5.4.1.a, Administrative Control (Procedures), states in part,
that written procedures shall be established, implemented, and maintained covering the
following activities including the applicable procedures recommended in Regulatory Guide 1.33, Appendix A, November 1972 (Safety Guide 33, November 1972). Safety Guide 33,
Appendix A,Section I.1 states in part, that maintenance that can affect the performance of
safety-related equipment should be properly planned and performed in accordance with
written procedures, documented instructions, or drawings appropriate to the circumstances.
Contrary to the above, since 2011, the licensee failed to maintain written procedures that
covered maintenance affecting the performance of safety-related equipment. Specifically,
maintenance procedures, 0SPP-CBL011, Splicing of Wires and Cables Using Tape, Rev.
11, and 0SPP-CBL011, Splicing of Wires and Cables Without Tape, Rev. 15, failed to
prevent heat shrink installation on a cable splice with existing degraded cable insulation.
Consequently, on February 27, 2023, the Unit 2 'A' core spray pump cable failed as a result
of an inadequate splice installed in 2011.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with
Section 2.3.2 of the Enforcement Policy.
Observation: Semi Annual Trend
The inspectors performed a trend analysis on the licensees corrective action program to
identify trends that could indicate the existence of a more significant safety issue. The
inspectors focused their review on equipment performance trends, but also considered the
results of inspector daily condition report screenings, licensee trending efforts, and licensee
human performance results. The review nominally considered the 6-month period of July -
December 2023, although some examples extended beyond those dates when the scope of
the trend warranted. The inspectors compared their results with the licensees analysis of
trends. Additionally, the inspectors reviewed the adequacy of corrective actions associated
with a sample of the issues identified in the licensees trend reports. The inspectors also
reviewed corrective action documents that were processed by the licensee to identify
potential adverse trends in the condition of structures, systems, and/or components as
evidenced by acceptance of long-standing non-conforming or degraded conditions.
During this review, the inspectors noted a negative trend regarding condenser circulating
water leaks in the vicinity of the condenser water-box inlet. Specifically, during 2023 the
inspectors noted seven separate documented circulating water leaks. All but one occurred on
the Unit 1 'A' south water-box.
Date Unit Location leak rate NCR
1/3/23 1 'A' South 20 gpm 2454643
1/24/23 1 'A' South <5 gpm 2457242
6/24/23 1 'A' North 25 gpm 2477177
10/5/23 1 'A' South 30 gpm 2489536
10/8/23 1 'A' South 150 gpm 2489704
10/30/23 1 'A' South 15 gpm 2492473
11/24/23 1 'A' South 8 gpm 2495624
Although the circulating water system is not safety-related, the leaks into the condenser bay
present some unique operational challenges as the water leakage is processed within the
plant radioactive waste system. Excessive condenser bay leakage can overwhelm the
radioactive processing system due to the sheer volume of water required to be
processed. Additionally, the 150 gpm leak noted on October 8, 2023, required operators to
perform an unplanned down power to 52 percent RTP in order to remove the affected
condenser water-box from service and effect repairs. These unplanned transients challenge
operators in the safe operation of the plant. The inspectors discussed this negative trend
during the quarterly exit meeting with licensee management.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On January 31, 2024, the inspectors presented the integrated inspection results to John
A. Krakuszeski, Site Vice President, and other members of the licensee staff.
On December 20, 2023, the inspectors presented the inspection results for the Post-
Approval for License Renewal Inspection to Jay Ratliff, Plant General Manager, and
other members of the licensee staff.