IR 05000443/2024002
| ML24219A267 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/06/2024 |
| From: | Matt Young Division of Operating Reactors |
| To: | Coffey B Florida Power & Light Co |
| References | |
| IR 2024002 | |
| Download: ML24219A267 (1) | |
Text
August 6, 2024
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:
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
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.
REACTOR SAFETY
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 power reduction following a geomagnetic disturbance of May 10, 2024
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator annual requalification exams in the simulator on June 10, 2024
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 remain capable of performing their intended function:
- (1) Containment air compressors on May 15, 2024
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (3 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) Risk management actions associated with transferring 'B' 125 volt direct current (dc)battery power supply to dc bus 11B from dc bus 11D on April 1, 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,
RADIATION SAFETY
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) 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 Initiating 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 inspection results to David Sluszka, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
293797
2477413
2479407
2482376
Corrective Action
Documents
Resulting from
Inspection
2489452
Corrective Action
Documents
2488103
2488398
2488462
2488558
Corrective Action
Documents
276532
2488155
2488858
2489113
Corrective Action
Documents
Resulting from
Inspection
2485212
Fire Plans
CMP-24-4886
CMP-24-4887
Work Orders
40618483
40855838
40861783
40950574
Corrective Action
Documents
2488333
2488386
2488495
Work Orders
40894984
71111.11Q Procedures
Human Performance Program Error Reduction Tools
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NRC Licensed Operator Exam Security
Revision 6
Licensed Operator Continuing Training Annual Operating
and Biennial Written Exams
Revision 9
Work Orders
40882498
40946792
Corrective Action
Documents
2436296
2436388
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
Procedures
Guarded Equipment
Revision 47
OS1048.14
Vital Bus 11B Operation
Revision 17
Work Orders
4086917901
408698001
Corrective Action
Documents
2447144
2456972
2459800
2462220
2487535
2488858
2489190
Work Orders
40948298
260988
Corrective Action
Documents
2462971
2464957
2466583
Corrective Action
Documents
2483532
2485216
2486249
2486516
2488331
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2488640
Corrective Action
Documents
Resulting from
Inspection
2487885
Drawings
FP23830
Emergency Diesel Generator System Operation and
Maintenance Manual
Revision 32
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
Surveillance
Revision 3
OX1413.01
A Train RHR Quarterly Flow and Valve Stroke Test and 18
Month Valve Stroke Observation
Revision 32
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
Miscellaneous
CFD 24-01
Seabrook Emergency Preparedness
01/31/2024
Procedures
EPDP-03
Emergency Preparedness Performance Indicators
Revision 27
Corrective Action
Documents
2483791
2483872
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Resulting from
Inspection
2483876
Corrective Action
Documents
2486736
Corrective Action
Documents
Resulting from
Inspection
2486671
2490369
Procedures
ON1246.03
GSU Trouble
Revision 23
ON1246.03
GSU Trouble
Revision 22