IR 05000324/2023002

Integrated Inspection Report 05000324/2023002 and 05000325/2023002

ML23215A125
Person / Time
Site:	Brunswick
Issue date:	08/04/2023
From:	Matthew Fannon Division Reactor Projects II
To:	Krakuszeski J Duke Energy Progress
References
IR 2023002
Download: ML23215A125 (1)

Text

SUBJECT:

BRUNSWICK STEAM ELECTRIC PLANT - INTEGRATED INSPECTION REPORT 05000324/2023002 AND 05000325/2023002

Dear John A. Krakuszeski:

On June 30, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Brunswick Steam Electric Plant. On July 27, 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.

No findings or violations of more than minor significance were identified during this inspection.

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:

DPR-62 and DPR-71

Report Numbers:

05000324/2023002 and 05000325/2023002

Enterprise Identifier:

I-2023-002-0014

Licensee:

Duke Energy Progress, LLC

Facility:

Brunswick Steam Electric Plant

Location:

Southport, NC

Inspection Dates:

April 1, 2023, to June 30, 2023

Inspectors:

C. Curran, Resident Inspector

J. Diaz-Velez, Senior Health Physicist

J. Rivera, Health Physicist

M. Schwieg, Senior Reactor Inspector

G. Smith, Senior Resident Inspector

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

No findings or violations of more than minor significance were identified.

Additional Tracking Items

None.

PLANT STATUS

Unit 1 began the period at 100 percent rated thermal power (RTP) and operated there until April 20, 2023, when the reactor automatically scrammed due to a failure of an auctioneered turbine control system power supply. Following replacement of the power supply, the reactor was taken critical on April 22, 2023, and a power ascension commenced. On April 27, 2023, the unit reached RTP and continued to operate there until June 2, 2023, when power was reduced to 60 percent RTP to perform a control rod sequence exchange and turbine valve testing. On June 4, 2023, following the valve testing and sequence exchange, the unit was restored to full RTP where it continued to operate for the remainder of the inspection period.

Unit 2 began the period at 100 percent RTP. On May 19, 2023, power was reduced to 60 percent RTP in order to perform a control rod improvement as well as maintenance on one of the two main generator output breakers. Following the control rod improvement and breaker maintenance, the unit was restored to full RTP on May 21, 2023, where the unit continued to operate until June 10, 2023, when an emergent down power to 86 percent RTP was executed due to a loss of the Whiteville offsite power line. On June 11, 2023, following restoration of the Whiteville line, the unit was restored to RTP 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 D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) Unit 1 nuclear service water (NSW) and conventional service water (CSW) while the Unit 1 A NSW pump was out of service (OOS) for planned maintenance on April 25, 2023 (2)1D and 2D control room air conditioning (CRAC) trains while the 2E CRAC train was OOS for replacement on May 9, 2023

(3) Unit 1 NSW and CSW while the Unit 1 A NSW pump was OOS for planned maintenance on May 17, 2023

(4) Unit 1 'B' residual heat removal (RHR) train while the 'A' RHR train was OOS for planned maintenance on June 23, 2023

(5) Unit 1 'A' standby liquid control (SLC) train while the 1B SLC pump was OOS for breaker preventative maintenance on June 27, 2023

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (2 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 20 and -4' elevation on May 15, 2023

(2) Control building 49 elevation (Main Control Room) on June 22, 2023

Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the onsite fire brigade training and performance during an unannounced fire drill in the emergency diesel generator building on May 26, 2023.

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors completed an evaluation of the internal flooding mitigation protections in the Unit 1 reactor building on April 13, 2023.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)

(1) The inspectors observed and evaluated an exam scenario given to an operating crew on May 31, 2023. The scenario consisted of a fire, a small break loss of coolant accident, and a steam leak. This evaluated scenario was part of an emergency preparedness operator examination, BNP-QD-23-01.

(2) The inspectors observed and evaluated an exam scenario given to an operating crew on June 7, 2023. The scenario consisted of a loss of condenser vacuum and a loss of offsite power and was performed in accordance with simulator guide, LOT-DAS-20.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (1 Sample)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) The inspectors focused on the circumstances surrounding an event that occurred on May 28, 2023, which involved the tripping of two circulating water intake pumps (CWIPs) due to high differential pressure across the associated traveling screens. The tripping of two CWIPs necessitated a down-power to 97.5 percent RTP (Nuclear Condition Report (NCR) 2474263) due to condenser vacuum concerns. The inspectors focused on any potential deficiencies in maintenance that could have led to this event.

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (4 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) Emergent failure of the Unit 2 'B' circulation water traveling screen on April 6, 2023

(2) Elevated risk during emergency diesel generator (EDG)-3 outage on June 8, 2023

(3) EDG-3 risk informed completion time performed on June 11, 2023, that authorized exceedance of the normal limiting condition for operation time of 7 days.

(4) Elevated risk during the Unit 1 'A' train RHR outage on June 22, 2023

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) EDG-4 fuel discharge strainer high differential pressure (NCR 2468157)

(2) Unit 1 safety relief valve 'F' seat leakage (NCR 2470212)

(3) Control rod '46-31' five percent slow scram time (NCR 2469709)

(4) Snubber 2-E41-60SS101 cold setting measurement out of tolerance (NCR 2432134)

(5) Unit 1 B reactor feed pump hydraulic leak (NCR 2471695)

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)

The inspectors evaluated the following temporary or permanent modifications:

(1) Temporary modification on the Unit 2 drywell integrator recorder in order to eliminate inaccurate readings (Engineering Change 422570)

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated forced outage activities from April 20, 2023, to April 23, 2023. This outage was caused by an automatic reactor scram caused by a turbine trip from 100 percent RTP.

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) (3 Samples)

(1)0PT-20.3A.5, "MSIV Leak Test," Rev. 15, following repairs to the Unit 2 C outboard main steam isolation valve (MSIV) in accordance with (IAW) work order (WO)

===20585086 (2)0OP-39, "Diesel Generator Operating Procedure, Rev. 200, performed on March 1, 2023, following diesel generator maintenance

(3) Unit 2 reactor core isolation cooling steam leak repair IAW WO 205910641 Surveillance Testing (IP Section 03.01)===

(1) Single Rod Scram Insertion Times Test, Rev. 84, performed on May 4, 2023 (2)0PT-19.6.0B, Visual Inspection of Inaccessible Hydraulic Snubbers, Rev. 22, IAW WO 20535444

Inservice Testing (IST) (IP Section 03.01) (1 Sample)

(1)0PT-09.2, "HPCI System Operability Test," performed on May 25, 2023, IAW WO

2056703803 Containment Isolation Valve (CIV) Testing (IP Section 03.01)

(1) Unit 2 C inboard MSIV local leak rate testing in accordance with 0PT-20.3A.5, "MSIV Leak Test," Rev. 15

71114.06 - Drill Evaluation

Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (2 Samples)

(1) The inspectors evaluated a quarterly emergency drill conducted on May 31, 2023, using drill guide BNP-QD-23-01. The emergency drill involved a fire in the intake area requiring off-site support (Notice of Unusual Event) followed by a small break loss of coolant accident (SBLOCA) resulting in high drywell pressure (Alert). A subsequent unisolable line break in the reactor water clean-up system led to a bypass of the drywell (Site Area Emergency) to the reactor building.

(2) The inspectors evaluated a quarterly emergency drill conducted on June 21, 2023, using drill guide BNP-QD-23-03. The emergency drill involved a SBLOCA (Alert)resulting in high drywell pressure. A subsequent unisolable steam line break in the reactor core isolation and cooling system lead to a bypass of the drywell (Site Area Emergency) to the reactor building.

71124.04 - Occupational Dose Assessment

Source Term Characterization (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated licensee performance as it pertains to radioactive source term characterization.

External Dosimetry (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated how the licensee processes, stores, and uses external dosimetry.

Internal Dosimetry (IP Section 03.03) (2 Samples)

The inspectors evaluated the following internal dose assessments:

(1) In-vitro tritium assessment

(2) Co-60 ingestion

Special Dosimetric Situations (IP Section 03.04) (2 Samples)

The inspectors evaluated the following special dosimetric situations:

(1) Declared Pregnant Workers

(2) EDEX

71124.05 - Radiation Monitoring Instrumentation

Walkdowns and Observations (IP Section 03.01) (10 Samples)

The inspectors evaluated the following radiation detection instrumentation during plant walkdowns:

(1) Instrument Issue Room, Ludlum Model 9-3, SN:12157, Calibrated: 12-Jan-23

(2) Instrument Issue Room, Ludlum Model 9-3, SN:7245, Calibrated: 27-Sep-22

(3) Instrument Issue Room, Ludlum Model 3078 (Stretch Scope), SN:13730, Calibrated:

26-Aug-22

(4) Instrument Issue Room, Ludlum Model 3078 (Stretch Scope), SN:13576, Calibrated:

16-Sep-22

(5) Instrument Issue Room, Mirion Telepole, SN:7601, Calibrated: 13-Dec-22

(6) Instrument Issue Room, Mirion Telepole, SN:21110, Calibrated: 13-Dec-22

(7) Instrument Issue Room, Ludlum Model 12-4 (Remball), SN:112681, Calibrated:

11-Aug-22

(8) Instrument Issue Room, Ludlum Model 12-4 (Remball), SN:3135, Calibrated:

6-Sep-22

(9) Instrument Issue Room, Ludlum Model L-177, SN:7076, Calibrated: 11-Jan-23

(10) Instrument Issue Room, Ludlum Model 3030P, SN:3567, Calibrated: 21-Mar-23

Calibration and Testing Program (IP Section 03.02) (11 Samples)

The inspectors evaluated the calibration and testing of the following radiation detection instruments:

(1) RCA EXIT, GEM 5, SN:13471, Calibrated: 10-Mar-22

(2) RCA EXIT, GEM 5, SN:1359, Calibrated: 24-Aug-22

(3) RCA EXIT, ARGOS 5AB, SN:12306, Calibrated: 10-Mar-22

(4) RCA EXIT, ARGOS 5AB, SN:12307, Calibrated: 10-Mar-22

(5) RCA EXIT, Cronos 4, SN:13593, Calibrated: 27-Jun-22

(6) RCA EXIT, Cronos 4, SN:13594, Calibrated: 3-Aug-22

(7) Unit 1 Main Steam Line Radiation Monitor (WO20243263 01, WO20356040 01, and WO20460548 01)

(8) Unit 1, High Range Drywell Area Radiation Monitors (WO20341331 01, WO20341336 01, WO20341337 01, WO20349311 01, WO20482171 01, WO20482233 01, WO20482236 01, WO20482237 01, and WO20482238 0)

(9) Unit 2, High Range Drywell Area Radiation Monitors (WO20411478 01, WO20411525 01, WO20411526 01, WO20411527 01, WO20411528 01, WO20535466 01, WO20535467 01, WO20535468 01, WO20535469 01, and WO20536088 01)

(10) Unit 1, Control Room Emergency Ventilation High Radiation Monitors (WO20272253 01, WO20272253 02, WO20416149 01, and WO20416149 02)

(11) Extended Fastscan Whole Body Counter (BNPFS1), Calibrated:22-Nov-22 Effluent Monitoring Calibration and Testing Program Sample (IP Section 03.03) (2 Samples)

The inspectors evaluated the calibration and maintenance of the following radioactive effluent monitoring and measurement instrumentation:

(1) Main Stack Radiation Monitoring System (WO20162530 01, WO20162530 04, WO20162532 01, WO20324282 01, WO20324282 04, and WO20324284 01)

(2) Liquid Waste Discharge Radiation Monitor (11-0MST-RLE22R) (WO20328011 01, and WO20468248 01)

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

MS05: Safety System Functional Failures (SSFFs) Sample (IP Section 02.04)===

(1) Unit 1 (April 1, 2022, through March 31, 2023)

(2) Unit 2 (April 1, 2022, through March 31, 2023)

MS06: Emergency AC Power Systems (IP Section 02.05) (2 Samples)

(1) Unit 1 (April 1, 2022, through March 31, 2023)

(2) Unit 2 (April 1, 2022, through March 31, 2023)

MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)

(1) Unit 1 (April 1, 2022, through March 31, 2023)

(2) Unit 2 (April 1, 2022, through March 31, 2023)

OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)

(1) April 1, 2021, through April 1, 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 2443190: Unit 1 'A' NSW sheared shear pin

71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)

(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) On April 20, 2023, the inspectors responded to an automatic reactor trip of Unit 1 due to a turbine trip from 100 percent power. The turbine trip was caused by a failed 24-volt auctioneered power supply in the turbine control system. The inspectors evaluated plant status, mitigating actions, and equipment failures, to enable the NRC to determine an appropriate response. The inspectors discussed the trip with operations, engineering, and licensee management personnel to gain an understanding of the event and assess follow-up actions. The inspectors reviewed operator actions taken to determine whether they were in accordance with licensee procedures and technical specifications, and reviewed unit and system indications to verify whether actions and system responses were as expected and designed. The inspectors found that operators responded to the situation appropriately and in accordance with plant procedures, and that plant systems responded to the trip as designed. The inspectors also reviewed the initial licensee notifications to verify that they met the requirements specified in Title 10 of the Code of Federal Regulations (10 CFR) 50.72. The event was reported to the NRC as event notification56478 and documented in the licensees corrective action program (CAP) as NCR 2469554. The inspectors reviewed the event against the criteria contained in IMC 0309, Reactive Inspection Decision Basis for Reactors, and determined that a reactive inspection was not required. The deterministic criteria for performing a reactive inspection were not met and the risk associated with the issue did not warrant any special inspection. Inspection was completed using the normal baseline inspection program.

INSPECTION RESULTS

Observation: Shear Pin Failure of Unit 1 'A' Nuclear Service Water (NSW) Pump Strainer 71152A The inspectors conducted a detailed review of NCR 2443190, 1A NSW strainer has sheared its shear pin. The inspectors chose this sample because it dealt with the mitigating systems cornerstone involving the safety-related NSW system. On September 20, 2022, the Unit 1 'A' NSW pump was restarted following screen wash bay cleaning. A manual backwash was performed in accordance with 1OP-43, "Service Water System Operating Procedure." After the manual backwash was secured, the pump was declared operable which occurred nine minutes following pump restart. Subsequently, on September 26, 2022, the Unit 1 'A' NSW strainer shear pin was discovered broken, and the pump was declared inoperable. Approximately 1/2 gallon of small shells were discovered in the bottom of the strainer. The inspectors noted that 1OP-43, Rev. 144, doesnt list a specific run time for the manual backwash. It was estimated the manual backwash ran for less than 5 minutes. In contrast, an automatic 24-hour backwash cycle takes 30 to 45 minutes. The inspectors noted that a longer backwash time (closer to the 30 to 45 minutes described in the operating procedure) could help remove more shells and potentially preclude a shear pin failure. Given the risk significance of the service water system, ensuring that the service water system is free of loose shells following bay cleaning will help reduce the number of strainer failures post-bay cleaning.

On September 19, 2022, the screen wash bay cleaning was performed IAW 0PM-STU500, "Service Water Intake Structure Inspection and Cleaning," Section 7.3. Step 13 requires the use of video recording to verify the as-left condition meets test acceptance criteria. During this inspection, the inspectors requested the video recording to verify no shells had settled under the service pump suctions following the bay cleaning. It was reported that maintenance personnel reviewed the live video from the divers to confirm the area under the pump was clear of debris in accordance with the procedure requirements. However, this video was not uploaded as part of the work order documentation and is not available for review. The inspectors concluded that the failure to maintain video recording of bay cleaning to ensure the pump suction areas are clean prior to pump starts made it difficult to verify this fact post-bay cleaning.

The inspectors noted a similar issue that occurred on January 6, 2021. This issue was documented as a non-cited violation (NCV)05000325/2021001-01 and resulted in the inoperability of the Unit 1 'B' CSW pump due to a clogged discharge strainer. Although beneficial to the overall health of the service water system, the inspectors observed that the bay cleaning can negatively affect the service water system if the restoration process is not conducted with a certain amount of due diligence. This is due to the potential to stir up debris during bay cleaning that could ultimately be pulled into one of the service water pump suctions following the restoration of a bay. This observation was communicated to the site leadership team. Ultimately, the inspectors concluded the correction actions and causal analysis utilized a conservative decision-making approach and provided reasonable assurance that bay cleaning activities will positively impact the availability of the service water system.

Observation: Semiannual Trend 71152S 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 January

- June 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 that NCR 2456652 described an event that occurred on January 15, 2023, that involved an overflow of the Unit 1 south RHR sump. This overflow was caused by a combination of failures in the Unit 1 reactor building equipment drain tank (RBEDT) pump and the south RHR sump pump. The RBEDT has a design overflow to the south RHR sump given a failure of the RBEDT pump. In the overflow event, the RBEDT pump motor failed and the in-leakage to the RBEDT overflowed to the south RHR sump. However, the south RHR sump pump failed to actuate due to issues with the level switch, thus causing the overflow to the -17' south RHR floor. This overflow resulted in a significant floor area becoming radiologically contaminated. Replacement of the RBEDT pump motor was delayed due to a lack of timely and suitable replacement available from the vendor. Throughout the first half of 2023, the licensee continued to be challenged in the prevention of overflowing the south RHR sump. Additionally, the lack of pumping capability from the RBEDT caused challenges to radioactive waste processing since the sumps are processed in different waste streams than the RBEDT effluent within the radioactive waste facility. One of the corrective actions included installing a temporary sump pump in the south RHR sump that was routed to the high pressure coolant injection sump in the adjacent room.

On June 5, 2023, another overflow event (NCR 2474952) occurred in the same south RHR room due to another failure of the installed RHR sump level switch. In this case, the temporary pump was not in use as the failure from January 15 was deemed repaired. The inspectors observed that the sump overflow issues appeared to challenge the licensee in terms of time and effort and required much focus from operations, radiation protection, engineering, and maintenance.

On June 14, 2023, NCR 2476097 was generated by the licensee and documented a potential negative trend regarding sump pump level switch failures. This NCR noted 27 work requests/NCRs generated since January 2020 that dealt with either a failure of a sump to pump, failure to secure pumping, and pump short cycling. Based on this NCR and the challenges resulting from the south RHR sump overflows, the inspectors concluded that the licensee has been unsuccessful in addressing these types of failures. 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 July 27, 2023, the inspectors presented the integrated inspection results to John A.

Krakuszeski, Site Vice President, and other members of the licensee staff.

On April 13, 2023, the inspectors presented the occupational radiation safety baseline inspection results to John A. Krakuszeski, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

71124.05

Corrective Action

Documents

NCR 02323566,

2402800,

2437011,

2454236, and

2462875

Various

Various