IR 05000443/2024002

Integrated Inspection Report 05000443/2024002 and Independent Spent Fuel Storage Installation Inspection Report 07200063/2024001

ML24219A267
Person / Time
Site:	Seabrook
Issue date:	08/06/2024
From:	Matt Young NRC/RGN-I/DORS
To:	Coffey B Florida Power & Light Co
References
IR 2024002
Download: ML24219A267 (1)

Text

August 6, 2024

Bob Coffey Executive Vice President, Nuclear Division and Chief Nuclear Officer Florida Power & Light Company 700 Universe Blvd.

Mail Stop: EX/JB Juno Beach, FL 33408

SUBJECT: SEABROOK STATION - INTEGRATED INSPECTION REPORT 05000443/2024002 AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION INSPECTION REPORT 07200063/2024001

Dear Bob Coffey:

On June 30, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Seabrook Station. On July 29, 2024, the NRC inspectors discussed the results of this inspection with David Sluszka, Site Vice President, 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 (10 CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Matt R. Young, Chief Projects Branch 2 Division of Operating Reactor Safety

Docket Nos. 05000443 and 07200063 License No. NPF-86

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000443 and 07200063

License Number: NPF-86

Report Numbers: 05000443/2024002 and 07200063/2024001

Enterprise Identifiers: I-2024-002- 0043 and I-2024- 001- 00060

Licensee: NextEra Energy Seabrook, LLC

Facility: Seabrook Station

Location: Seabrook, New Hampshire

Inspection Dates: April 1, 2024 to June 30, 2024

Inspectors: T. Daun, Senior Resident Inspector E. Allen, Resident Inspector N. Eckhoff, Health Physicist C. Hargest, Health Physicist M. Henrion, Senior Health Physicist A. Kostick, Technical Assistant

Approved By: Matt R. Young, Chief Projects Branch 2 Division of Operating Reactor Safety

Enclosure

SUMMARY

The U.S. NRC continued monitoring the licensees performance by conducting an integrated inspection at Seabrook 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

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

Additional Tracking Items

None.

PLANT STATUS

Seabrook Station began the inspection period operating at 100 percent rated thermal power. On May 10, 2024, the plant performed a rapid load reduction to 58 percent rated thermal power in response to geomagnetically induced currents caused by a solar storm. Following the solar storm, the plant returned to 100 percent rated thermal power on May 12, 2024, and remained at or near full power 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.

71111.01 - Adverse Weather Protection

Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal high temperatures for the following systems: service water, primary component cooling water, and transformer cooling fans on June 12, 2024

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) 'B' emergency diesel generator and support systems during 'A' emergency diesel generator maintenance the week of June 10, 2024

(2) Supplemental emergency power system diesel generators during 'A' emergency diesel generator maintenance the week of June 10, 2024

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 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) Main steam and feedwater pipe enclosure (MS-F-3B-Z) on April 29, 2024

(2) 'A' emergency diesel generator room (DG-F-2A-A) on June 12, 2024

(3) Supplemental emergency power system enclosures and switchgear (SEPS-F-1-0) on June 14, 2024

(4) 'B' switchgear room (CB-F-1B-A) on June 21, 2024

(5) Control room computer room (CB-F-3C-A) on June 25, 2024

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) 'A' emergency diesel generator jacket water heat exchanger on June 24, 2024

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 following:

• Testing of the emergency feedwater system on April 24, 2024

• Rapid poweduction folling a geomagnetic diste of M 10, 20

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( The ipectorserv and uaticensed or requalificion sn timorJ, 2024

- Menancefftivs

MenancefftivenessIPtion 03.01) (1 S

The ipectors evted t efftivsf maienance tourthe fling strtes, systs,sn cabl rformi their iended functi:

( Content air cpresssM 15, 2024

- Menance Risksssmtsmgent Wkontr

Risksssmt and MenteIP Sti) (3 Sample

The ipectors evted t accacyomsf risk assessmentsor t fling planned and emgentork activiti to enseonfirion c and opriekontrse addrs:

( Riskanagement actis assiittrsferring 'B' 125 vo rt currt)batteryeryo r dc 11D on Ail, 2024

(2) Risk management actions associated with 'A' emergency diesel generator maintenance on June 14, 2024

(3) Risk management actions associated with removal of flex equipment for annual maintenance on June 25, 2024

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) Non-vital bus voltage drifting on June 1, 2024

(2) Emergency switchgear 3B reserve auxiliary transformer differential relay on June 6, 2024

(3) Emergency feedwater steam supply valve seat leakage increase on June 9, 2024

(4) Primary component cooling water head tank level detector failure on June 18, 2024

(5) 'A' emergency diesel generator jacket water heat exchanger service water flow indication on June 24, 2024

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) 'A' steam pressure instrument tubing modifications on June 24, 2024

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 (IP Section 03.01) (6 Samples)

(1) Charging pump motor trip checks following the replacement of charging pump 2A 4160 kV breaker on April 24, 2024

(2) Containment enclosure building cooling fan (EAH-FN-5A) surveillance following replacement of the fan motor on May 16, 2024

(3) Valve stroke of component cooling water valve 1298 following the rebuild of the pneumatic actuator on May 20, 2024

(4) 'A' emergency diesel generator lube oil heat exchanger temperature control valve following replacement of power pills on June 17, 2024

(5) 'A' emergency diesel generator following major maintenance window on June 18, 2024

(6) 'B' loop service water following maintenance on the 'D' service water pump on June 27, 2024

Surveillance Testing (IP Section 03.01) (3 Samples)

(1) Diesel generator air start system valves quarterly surveillance test on April 10, 2024

(2) 'A' residual heat removal 18-month emergency safeguards actuation system automatic start relay (K601) surveillance test on April 28, 2024

(3) Primary air handling damper 35A timing relay surveillance test on June 21, 2024

71114.06 - Drill Evaluation

Additional Drill and/or Training Evolution ( IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) The inspectors evaluated the conduct of emergency planning classifications and notifications during licensed operator annual exams on June 10,

71124.07 - Radiological Environmental Monitoring Program

Environmental Monitoring Equipment and Sampling (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated environmental monitoring equipment and observed collection of environmental samples

Radiological Environmental Monitoring Program (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the implementation of the licensees radiological environmental monitoring program

Groundwater Protection Initiative Implementation (IP Section 03.03) (1 Sample)

(1) The inspectors evaluated the licensees implementation of the groundwater protection initiative program to identify incomplete or discontinued program elements

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

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

(1) For the period April 1, 2023 through March 31, 2024

MS06: Emergency AC Power Systems (IP Section 02.05) (1 Sample)

(1) For the period April 1, 2023 through March 31, 2024

MS07: High Pressure Injection Systems (IP Section 02.06) (1 Sample)

(1) For the period April 1, 2023 through March 31, 2024

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

(1) The inspectors reviewed the licensees corrective action program for potential adverse trends that might be indicative of a more significant safety issue.

71153 - Follow Up of Events and Notices of Enforcement Discretion Personnel Performance (IP Section 03.03)

Inspectors responded to the control room and reviewed operator logs, computer data, recorder data, procedural requirements, and related training. Inspectors also interviewed staff involved and reviewed the licensee's transient assessment.

(1) The inspectors evaluated a rapid load reduction and down power in response to a geomagnetic storm on May 10,

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

60855 - Operation of an Independent Spent Fuel Storage Installation

Operation of an Independent Spent Fuel Storage Installation (1 Sample)

(1) The inspectors evaluated the licensee's activates related to long-term operation and monitoring of their independent spent fuel storage installation

INSPECTION RESULTS

Observation: Semiannual Trend Review 71152S The inspectors reviewed Seabrooks corrective action program for trends that might be indicative of more significant safety issues. The inspectors reviewed condition reports, level one assessments, system health reports, and control room/panel deficiencies. In particular, the inspectors evaluated the operator challenges program including an audit of control room deficiencies, control board notifications, and operator workarounds.

Based on the overall results of the semiannual trend review, the inspectors determined that issues were appropriately evaluated by Seabrook staff for potential trends and resolved within the scope of the corrective action program and other requisite procedures.

Minor Performance Deficiency 71153 Operator Performance During Solar Magnetic Disturbance

Minor Performance Deficiency: Seabrook operating procedure ON1246.03, Generator Step -

up (GSU) Transformer Trouble, provides response actions for a solar magnetic disturbance event which has the potential to result in elevated geomagnetically induced current (GIC). On May 10, 2024, Seabrook entered this procedure conservatively at 08:26 based upon forecasted solar magnetic disturbances. Various GIC pulses were observed throughout the day. The start of a GIC pulse is indicated by a control room alarm when GIC exceeds 60 amps and remains until GIC reduces to less than 60 amps. Step 9b of ON1246.03 directs operators to check if direct current neutral ground current is less than limits and if it is not, reduce load to less than 700 megawatt electric (Mwe) in 30 minutes. Step 9 also directs monitoring of GSU hot spot winding temperatures and GSU oil temperatures during the GIC pulse. If either of these limits are exceeded, operators are directed to trip the reactor and remove the GSUs from service. Attachment F of ON1246.03 is used to determine the GIC limit which is based on plant operating power, GIC pulse, and the number of GSU coolers that are in service. Attachment F defines the GIC pulse as the time GIC exceeds 60 amps until it reduces below 60 amps.

At 19:06, a GIC pulse started and a maximum GIC current of 232 amps was observed at approximately 19:11. The current limit for a 5- 10 minute GIC pulse is 279 amps. The GIC pulse continued beyond the 10- minute period and the maximum allowable current for a 10- 15 minute GIC pulse is 178 amps. This GIC pulse ended at 19:18. At 19:38, the control room entered their rapid down power procedure and commenced reducing load to less than 700 Mwe. At 20:07, a turbine load of less than 700 Mwe was achieved.

Screening: The inspectors determined the performance deficiency was minor.

Inspectors determined that failure to follow procedural guidance to commence load reduction once GIC current exceeded the allowable limit was a performance deficiency that was preventable.

Specifically, the procedure required a rapid load reduction to reduce power to less than 700 Mwe within 30 minutes of exceeding GIC current, which occurred at 19:16, but the delay in the start of the power reduction resulted in exceeding the 30 minute requirement to be less than 700 Mwe by 21 minutes. While it is associated with protection against external factors attribute of the I nitiating Events cornerstone, no increase in GSU hot spot winding temperatures or GSU oil temperatures were seen during the event.

The licensee captured these observations in their corrective action program as AR 02486671 and have completed training for all licensed operators on ON1246.03 as well as the details of this event.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On July 2, 2024, the inspectors presented the radiation safety inspection results to David Sluszka, Site Vice President, and other members of the licensee staff.

• On July 10, 2024, the inspectors presented the independent spent fuel storage installation inspection results to David Sluszka, Site Vice President, and other members of the licensee staff.

• On July 29, 2024, the inspectors presented the integrated inspectionresults to David Sluszka, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action 02293797

Documents 02477413

2479407

2482376

Corrective Action 02489452

Documents

Resulting from

Inspection

71111.04 Corrective Action 02488103

Documents 02488398

2488462

2488558

71111.05 Corrective Action 02276532

Documents 02488155

2488858

2489113

Corrective Action 02485212

Documents

Resulting from

Inspection

Fire Plans CMP-24-4886

CMP-24-4887

Work Orders 40618483

40855838

40861783

40950574

71111.07A Corrective Action 02488333

Documents 02488386

2488495

Work Orders 40894984

71111.11Q Procedures PI-AA-103-1000 Human Performance Program Error Reduction Tools

Inspection Type Designation Description or Title Revision or

Procedure Date

TR-AA-220-1002 NRC Licensed Operator Exam Security Revision 6

TR-AA-220-1004 Licensed Operator Continuing Training Annual Operating Revision 9

and Biennial Written Exams

Work Orders 40882498

40946792

71111.12 Corrective Action 02436296

Documents 02436388

2475049

Procedures ECA-1.1 Loss of Emergency Coolant Recirculation Revision 39

ECA-2.1 Uncontrolled Depressurization of all Steam Generators Revision 41

ON1242.01 Loss of Instrument Air Revision 17

ON1242.02 Loss of Containment Instrument Air Revision 13

71111.13 Procedures OP-AA-102-1003 Guarded Equipment Revision 47

OS1048.14 Vital Bus 11B Operation Revision 17

Work Orders 4086917901

408698001

71111.15 Corrective Action 02447144

Documents 02456972

2459800

2462220

2487535

2488858

2489190

Work Orders 40948298

260988

71111.18 Corrective Action 02462971

Documents 02464957

2466583

71111.24 Corrective Action 02483532

Documents 02485216

2486249

2486516

2488331

Inspection Type Designation Description or Title Revision or

Procedure Date

2488640

Corrective Action 02487885

Documents

Resulting from

Inspection

Drawings FP23830 Emergency Diesel Generator System Operation and Revision 32

Maintenance Manual

Procedures LS0550.09 Timing Relay Acceptance Testing and Maintenance Program Revision 35

LS0563.177 1-CS-P-2-A Trip Checks Revision 2

MA3.5 Post-Maintenance Testing Revision 28

OS1423.09 Containment Enclosure Cooling System 31 Day Surveillance Revision 8

OS1426.36 Diesel Generator Air Start System Valves Quarterly Revision 3

Surveillance

OX1413.01 A Train RHR Quarterly Flow and Valve Stroke Test and 18 Revision 32

Month Valve Stroke Observation

OX1426.26 DG 1A Semiannual Operability Surveillance Revision 35

OX1456.21 Train A ESFAS Slave Relay K601 Go Test Revision 16

OX1456.81 Operability Testing Of IST Valves Revision 44

Work Orders 40851802

40861796

40881748

40882420

40883379

40883380

40893514

40894944

40906935

40908060

40976659

71114.06 Miscellaneous CFD 24-01 Seabrook Emergency Preparedness 01/31/2024

Procedures EPDP-03 Emergency Preparedness Performance Indicators Revision 27

71124.07 Corrective Action 02483791

Documents 02483872

Inspection Type Designation Description or Title Revision or

Procedure Date

Resulting from 02483876

Inspection

71153 Corrective Action 02486736

Documents

Corrective Action 02486671

Documents 02490369

Resulting from

Inspection

Procedures ON1246.03 GSU Trouble Revision 23

ON1246.03 GSU Trouble Revision 22

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