IR 05000387/2023004

Integrated Inspection Report 05000387/2023004 and 05000388/2023004

ML24038A011
Person / Time
Site:	Susquehanna
Issue date:	02/07/2024
From:	Jon Greives NRC/RGN-I/DORS
To:	Berryman B Susquehanna
References
IR 2023004
Download: ML24038A011 (1)

Text

February 7, 2024

SUBJECT:

SUSQUEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2 -

INTEGRATED INSPECTION REPORT 05000387/2023004 AND 05000388/2023004

Dear Brad Berryman:

On December 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Susquehanna Steam Electric Station, Units 1 and 2. On January 18, 2024, the NRC inspectors discussed the results of this inspection with Derek Jones, Plant Manager, and other members of your staff. The results of this inspection are documented in the enclosed report.

Two findings of very low safety significance (Green) are documented in this report. 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 I; the Director, Office of Enforcement; and the NRC Resident Inspector at Susquehanna Steam Electric Station, Units 1 and 2.

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 I; and the NRC Resident Inspector at Susquehanna Steam Electric Station, Units 1 and 2. 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, Jonathan E. Greives, Chief Projects Branch 4 Division of Operating Reactor Safety

Docket Nos. 05000387 and 05000388 License Nos. NPF-14 and NPF -22

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000387 and 05000388

License Numbers: NPF-14 and NPF-22

Report Numbers: 05000387/2023004 and 05000388/2023004

Enterprise Identifier: I-2023-004- 0042

Licensee: Susquehanna Nuclear, LLC

Facility: Susquehanna Steam Electric Station, Units 1 and 2

Location: 769 Salem Blvd., Berwick, PA

Inspection Dates: October 1, 2023 to December 31, 2023

Inspectors: C. Highley, Senior Resident Inspector E. Brady, Resident Inspector J. DeBoer, Senior Emergency Preparedness Inspector R. Fisher, Emergency Preparedness Specialist L. Grimes, Resident Inspector S. Haney, Senior Project Engineer D. McHugh, Reactor Inspector S. Mercurio, Emergency Preparedness Inspector M. Ordoyne, Physical Security Inspector P. Ott, Operations Engineer T. Setzer, Senior Operations Engineer

Approved By: Jonathan E. Greives, Chief Projects Branch 4 Division of Operating Reactor Safety

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Susquehanna Steam Electric Station,

Units 1 and 2, 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 of Unit 1 High-Pressure Coolant Injection Stop Valve from Fully Closing Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [P.5] - 71153 Systems NCV 05000387/2023004-01 Operating Open/Closed Experience The inspectors determined there was a self-revealing Green finding and associated non-cited violation ( NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B,

Criterion XVI, Corrective Action, when in October 2022, the licensee failed to identify and correct a condition adverse to quality associated with condensate accumulation in the high-pressure coolant injection (HPCI) system. As a result, condensation leaked through the packing and corro ded the stem of the HPCI stop valve (FV15612) to piston actuator, which subsequently rendered the valve unable to fully close during lubricating oil system functional testing on April 7, 2023.

Inadequate Maintenance Procedure Resulted in Exceeding Secondary Containment Bypass Leakage Limit Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.3] - Change 71153 NCV 05000388 /2023004-02 Management Open/Closed The inspectors determined a self-revealing Green finding and associated NCV of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, and Technical Specification (TS) 3.6.1.3, Action E1, occurred when the licensee operated with a penetration that exceeded the secondary containment bypass leakage ( SCBL ) limit for longer than allowed by TS 3.6.1.3. Specifically, the feedwater inboard containment isolation valve ( CIV), 241F010B, failed to pressurize during testing as a result of binding at the hinge pin to disc interface caused by insufficient side-to-side clearances due to the licensee's inadequate maintenance procedure.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000387,05000388/ LER 2023-001-00 for 71153 Closed 2023- 001- 00 Susquehanna Steam Electric Station, Units 1 and 2,

Inadvertent Contact Between Relay Cover and Relay Trip Contacts Resulted in Automatic Actuation of the

'B' Emergency Diesel Generator LER 05000387/2023-002-00 LER 2023-002-00 for 71153 Closed Susquehanna Steam Electric Station, Unit 1, Unplanned lnoperability of the High-Pressure Coolant Injection (HPCI) System Due to Failure of the HPCI Turbine Stop Valve to Fully Close,

Most Likely Due to Internal Corrosion and Mechanical Binding of the Valve Hydraulic Drive LER 05000388/2023-001-00 LER 2023-001-00 for 71153 Closed Susquehanna Steam Electric Station, Unit 2, Secondary Containment Bypass Leakage Limit Exceeded Due to Inadequate Procedure Guidance Resulting in Failure of the Inboard Containment Isolation Valve to Close and Pressurize

PLANT STATUS

Unit 1 began the inspection period at or near rated thermal power. On November 10, 2023, the unit scrammed due to a main condenser vacuum degradation. The unit was returned to rated thermal power on November 23. 2023. On December 8, 2023, the unit was down powered to percent for a rod sequence exchange. On December 9, 2023, the unit was returned to rated thermal power and remained at or near rated thermal power for the remainder of the inspection period.

Unit 2 began the inspection period at or near rated thermal power. On December 15, 2023, the unit was down powered to 75 percent for scram time testing and a rod sequence exchange. On December 15, 2023, the unit was returned to rated thermal power and remained at or near rated thermal 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, conducted routine reviews using IP 71152, Problem Identification and Resolution, 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 (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the following systems: heating, ventilation, and air conditioning; offgas; and heat trace circuitry on November 24, 2023.

71111.04 - Equipment Alignment

Partial Walkdown (IP Section 03.01) (2 Samples)

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

(1) Unit 2, residual heat removal valves in equipment spaces on November 1, 2023.

(2) Unit 1, residual heat removal division 1 on November 8, 2023

71111.05 - Fire Protection

Fire Area Walkdown and Inspection (IP Section 03.01) (3 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Unit 1, reactor building, 749-foot elevation, fire zone (FZ) 1-5A-N, 1-5A-S, and 1-5F on October 2, 2023

(2) Unit 1, turbine building, 729-foot elevation, FZ 0-35A and 1-35C, on October 17, 2023

(3) Unit 2, reactor building, 683-foot elevation, FZ 2-3A, 2-3B-N, and 2-3B-W, on November 2, 2023

71111.06 - Flood Protection Measures

Flooding (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections on the 645-foot elevation in Unit 1 on December 15, 2023.

71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance

Requalification Examination Results (IP Section 03.03) (1 Sample)

(1) The inspectors reviewed and evaluated the licensed operator examination failure rates for the requalification annual operating exam administered in September 2023 and the biennial written examinations completed in 2022.

71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Requalification Program (IP Section 03.04) (1 Sample)

(1) Biennial Requalification Written Examinations

The inspectors evaluated the quality of the licensed operator biennial requalification written examination administered in 2022.

Annual Requalification Operating Tests

The inspectors evaluated the adequacy of the facility licensees annual requalification operating test.

Administration of an Annual Requalification Operating Test

The inspectors evaluated the effectiveness of the facility licensee in administering requalification operating tests required by 10 CFR 55.59(a)(2) and that the facility licensee is effectively evaluating their licensed operators for mastery of training objectives.

Requalification Examination Security

The inspectors evaluated the ability of the facility licensee to safeguard examination material, such that the examination is not compromised.

Remedial Training and Re-examinations

The inspectors evaluated the effectiveness of remedial training conducted by the licensee and reviewed the adequacy of re-examinations for licensed operators who did not pass a required requalification examination.

Operator License Conditions

The inspectors evaluated the licensees program for ensuring that licensed operators meet the conditions of their licenses.

Control Room Simulator

The inspectors evaluated the adequacy of the facility licensees control room simulator in modeling the actual plant and for meeting the requirements contained in 10 CFR 55.46.

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 Unit Common control room during scram time testing, various annunciator alarm responses, and duty team call concerning replacement of a controller for the control rod drive flow in Unit 1 on December 15, 2023.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated the Unit Common requalification test based on LOR-EXM-04 of low power operations with a trip of the residual heat removal pump with loss of condensate transfer pump that drains/voids the residual heat removal loop, two feed water flow transmitters fail downscale on the same reactor feed pump, spurious main turbine trip/electrical anticipatory transient without scram, stuck open safety relief valve with tailpipe rupture, division 1 residual heat removal containment spray logic failure, division 2 residual heat removal drywell spray valve fails to open, and tailpipe rupture worsens/emergency depressurization on October 10, 2023.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (3 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) Unit 2, maintenance rule a(1) determination for 'B' 4KV (4160 VAC) emergency safeguard system bus, 2A202, CR-2023-05225, on December 12, 2023

(2) Unit 2, maintenance rule a(1) determination for SCBL penetration X9B - 241F010B,

===241818B, HV241F032B, CR-2023- 05228, and CR-2023- 05057, on December 12, 2023

(3) Unit Common, 'B' emergency service water piping corrosion in vault 06, CR-2023-11433 and CR-2023-11521, on December 12, 2023

Quality Control (IP Section 03.02)===

The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:

(1) Unit Common, quality control of receipt of parts into the warehouse for work order (WO) 2215795, WO 2258094, WO 2258111, CR-2020- 16932, CR-2020- 16935, and CR-2020-17053, on December 28, 2023

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management (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) Unit Common, elevated risk due to T-10 transformer planned/emergent maintenance on October 8, 2023

71111.20 - Refueling and Other Outage Activities

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

(1) The inspectors evaluated forced outage due to loss of condenser vacuum which included a dry well entry, search for unidentified leakage in the dry well, search for source of main condenser in leakage, and low power operation activities from November 11 to 19, 2023.

71114.02 - Alert and Notification System Testing

Inspection Review (IP Sections 02.01 to 02.04) (1 Sample)

(1) The inspectors evaluated the licensee's maintenance and testing of the alert and notification system from October 16 through 19, 2023, for the period of October 2021 through September 2023.

71114.03 - Emergency Response Organization Staffing and Augmentation System

Inspection Review (IP Sections 02.01 to 02.02) (1 Sample)

(1) The inspectors evaluated the readiness of the licensees Emergency Preparedness Organization from October 16 through 19, 2023.

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Sections 02.01 to 02.03) (1 Sample)

(1) The inspectors evaluated the following submitted Emergency Action Level and Emergency Plan changes:

• E2019- 04- 03- 01, Revision 1

• E2022- 09- 08- 01, Revision 0

• E2022- 09-14- 01-01, Revision 0

This evaluation does not constitute NRC approval.

71114.05 - Maintenance of Emergency Preparedness

Inspection Review (IP Sections 02.01 to 02.11) (1 Sample)

(1) The inspectors evaluated the maintenance of the emergency preparedness program from October 16 through 19, 2023, for the period from October 2021 through September

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) Unit 1, July 1, 2022 through June 30, 2023

(2) Unit 2, July 1, 2022 through June 30, 2023

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

(1) Unit 1, July 1, 2022 through June 30, 2023

(2) Unit 2, July 1, 2022 through June 30, 2023

MS07: High-Pressure Injection Systems (IP Section 02.06) (2 Samples)

(1) Unit 1, July 1, 2022 through June 30, 2023

(2) Unit 2, July 1, 2022 through June 30, 2023

MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)

(1) Unit 1, July 1, 2022 through June 30, 2023

(2) Unit 2, July 1, 2022 through June 30, 2023

MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)

(1) Unit 1, October 1, 2022 through September 30, 2023

(2) Unit 2, October 1, 2022 through September 30, 2023

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

(1) Unit 1, October 1, 2022 through September 30, 2023

(2) Unit 2, October 1, 2022 through September 30, 2023

EP01: Drill/Exercise Performance (IP Section 02.12) (1 Sample)

(1) July 1, 2022 through June 30, 2023

EP02: Emergency Response Organization Drill Participation (IP Section 02.13) (1 Sample)

(1) July 1, 2022 through June 30, 2023

EP03: Alert And Notification System Reliability (IP Section 02.14) (1 Sample)

(1) July 1, 2022 through June 30, 2023

71152A - Annual Follow-up of Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)

The inspectors reviewed the licensees implementation of its corrective action program (CAP) related to the following issues:

(1) Review of screening for security equipment condition reports in accordance with site implementing procedures and the Physical Security Plan from November 27 to 30, 2023

(2) Unit 1, HPCI stop valve failure to completely close on December 22, 2023

(3) Installation of valves in the American Society of Mechanical Engineers,Section III, Class 3, portion of the reactor water cleanup system, WO 2215795, WO 2258094, and WO 2258111, on December 28, 202f3.

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

(1) The inspectors reviewed the licensees CAP for potential adverse trends in second, third, and fourth quarters of 2023 that might be indicative of a more significant safety issue.

71153 - Follow-up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 05000387 and 05000388/2023-001-00, Inadvertent Contact Between Relay Cover and Relay Trip Contacts Resulted in Automatic Actuation of the 'B' Emergency Diesel Generator (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23142A269): The inspection conclusions associated with this LER are documented in this report under the Inspection Results Section, Minor Violation. This LER is closed.

(2) LER 05000387/2023-002-00, Unplanned lnoperability of the High-Pressure Coolant Injection (HPCI) System Due to Failure of the HPCI Turbine Stop Valve to Fully Close, Most Likely Due to Internal Corrosion and Mechanical Binding of the Valve Hydraulic Drive (ML23157A176): The inspection conclusions associated with this LER are documented in this report under the Inspection Results Section, NCV 05000387/2023004-01. This LER is closed.

(3) LER 05000388/2023-001-00, Secondary Containment Bypass Leakage Limit Exceeded Due to Inadequate Procedure Guidance Resulting in Failure of the Inboard Containment Isolation Valve to Close and Pressurize (ML23145A178): The inspection conclusions associated with this LER are documented in this report under the Inspection Results Section, NCV 05000388/2023004-02. This LER is closed.

INSPECTION RESULTS

Minor Performance Deficiency: Security Equipment Condition Adverse to 71152A Quality - Corrective Action Program The inspectors identified that the licensee failed to correctly implement station CAP procedures. Specifically, from August 14 to November 20, 2023, it was identified that condition reports affecting security equipment were not properly screened in accordance with station CAP procedures.

Screening: The inspectors determined the performance deficiency was minor because the inspectors review of the licensee documentation associated with condition reports for security equipment deficiencies did not identify any deficiencies that were not being corrected in a timely manner. Therefore, this would not lead to a more significant safety concern.

Minor Performance Deficiency: Inadequate Receipt Inspections for the American 71152A Society of Mechanical Engineers,Section III, Class 3, Valves for Non-Safety System Installations The installation of new valves into the reactor water cleanup system in the non-safety section, HV14507B, HV14531A, HV14532A, and HV14532B, was required to be certified by the American Society of Mechanical Engineers,Section III, C lass 3, with an NPV-1 form (certification holders data report for nuclear pumps or valves) signed for certification of compliance, certification of inspection, and an N stamp applied to the paperwork. However, the NPV-1 form was not signed for certification of inspection and the N stamp was not applied. Licensee procedure, NOSP-QA-303, R eceipt of Inspection Requirements, was not followed. Specifically, the validation of the paperwork during the receipt inspection, steps 5.2.5 and 5.2.7 of NOSP-QA-303, did not identify that the appropriate signatures were documented to ensure the conformance to and tracking of the quality of the valves and the compliance to the purchase order.

Screening: The inspectors determined the performance deficiency was minor because the licensees failure to perform the receipt inspection in accordance with the procedure did not adversely affect any cornerstone objective.

Observation: Semiannual Trend Review of Issues Associated with the 71152S Containment H2/O2 Analyzers The inspectors performed a semiannual trend review of the site s issues associated with the containment H2/O2 analyzers.

As part of this review, the inspectors included repetitive or closely related issues documented by the licensee in the CAP database, trend reports, site performance indicators, major equipment problem lists, system health reports, maintenance rule assessments, and maintenance or CAP backlogs. The inspectors also reviewed how the licensee s CAP evaluated and responded to individual issues identified by the NRC inspectors during routine plant walkdowns and daily condition report reviews.

The inspectors reviewed the licensees CAP condition reports, action requests, and the associated corrective actions for potential adverse trends associated with the containment H2/O2 analyzer failures that might be indicative of a more significant safety issue f rom April through November 2023. The inspectors observed that the station had taken action to correct the issues associated with the failures of the H2/O2 containment analyzers and had placed Unit 2 H2/O2 containment analyzers into (a)(1) status in accordance with the maintenance rule with an approved plan (CR-2023-10473) as of June 2023 to improve the reliability and availability of that system. The inspectors did not identify any violations or performance deficiencies during the review.

Failure of Unit 1 High -Pressure Coolant Injection Stop Valve from Fully Closing Cornerstone Significance Cross -C utting Report Aspect Section Mitigating Green [P.5] - 71153 Systems NCV 05000387/2023004 - 01 Operating Open/Closed Experience The inspectors determined there was a self-reveal ing Green finding and associated NCV of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, when in October 2022, the licensee failed to identify and correct a condition adverse to quality associated with condensate accumulation in the HPCI system.

As a result, c ondensation leaked through the packing and corroded the stem of the HPCI stop valve (FV15612) to piston actuator, which subsequently rendered the valve unable to fully close during lubricating oil system functional testing on April 7, 2023.

Description:

The HPCI system p rovide s emergency core cooling under loss of coolant accident conditions that do not result in a rapid depressurization of the reactor vessel, p ermits plant shutdown while maintaining vessel water inventory until the low-pressure coolant injection systems and/or core spray systems can be used, and acts as a backup to the Reactor Core Isolation Cooling system for high-pressure makeup during normal shutdown operations.

The s ystem is capable of automatic initiation, during which the HPCI stop valve (FV15612)opens and allows for the admittance of steam to the HPCI turbine. The system is designed to maintain level between the high and low level setpoints by closing the stop valve when the high level setpoint is reached and reopening the valve when the low level setpoint is reached.

The stop valve stem has several limit switches attached, one of which resets the ramp generator signal convertor (RGSC) circuit. The HPCI speed control system uses the stop valve position to initiate the ramp function of the RGSC circuit which functions to control the speed of the turbine to prevent controller overshoot and resulting turbine overspeed during starting and restarts of the HPCI pump. If the stop valve is prevented from closing such that the full closed limit switch is unable to pick up, the ramp generator is unable to reset and a successful HPCI start is no longer assured.

In October 2022, condition reports were generated when condensed steam was identified to be leaking from around the valve stem on the stop valve due to leakby past the closed HPCI turbine steam supply valve (HC155F001) upstream. Operations started tracking the condition in an adverse condition monitoring plan (ACMP). Engineering developed ER-2003 risk evaluation for the leaking steam supply valve. The ER -2003 bridging strategy for early identification of degradation to the HPCI included actions to monitor the water content in the quarterly oil samples and HPCI vibrations. At the time, E ngineering did not identify that this condition could have an impact on HPCI stop valve operation.

Weekly functional testing of the HPCI lubricating oil system includes verification that the stop valve returns to the full closed position. Lubricating oil system functional tests between February 10 to 21, 2023, identified a delay in RGSC governor reset following stop valve closure. During a delayed reset, if the system received an initiation signal, the turbine would try to start up at full load and most likely trip on overspeed. This prompted Operations to request Engineering input on a prompt operability determination (POD). POD ACT-01-CR-2023- 02899 determined that Unit 1 HPCI remained capable of performing its design function.

Between the issuance of POD ACT- 01-CR-2023- 02899 on February 24 and March 31, 2023, Unit 1 HPCI was able to successfully complete weekly lubricating oil system functional testing. During the weekly HPCI lubricating oil system functional test on April 7, 2023, the HPCI turbine stop valve failed to fully close upon completion of the test and did not reset the RGSC. Operations entered Limiting Condition for Operation 3.5.1.d - HPCI system inoperable, with an 8-hour report to NRC for potential loss of a safety function.

On April 8, 2023, corrective actions were taken to clean and lubricate the actuator shaft.

Operations cycled the valve until it operated as expected. The HPCI lubricating oil functional test preventive maintenance was reperformed successfully, and Unit 1 exited Limiting Condition for Operation 3.5.1.

The licensee later determined that the stop valve failed to close due to internal corrosion. The HPCI turbine stop valve is an angled valve that is installed in an upside-down orientation with the hydraulic actuator connected via the stem directly below the packing area of the stop valve. As a result, any packing leakage travels down the stem and into the hydraulic actuator.

The inspectors noted that the licensee has operating experience from 2006 and 2009 where condensed steam from leakage past the seat of the HPCI turbine steam supply valve accumulated on the packing of the upside-down oriented stop valve. The accumulated condensation subsequently caused corrosion product build up to levels that prevented the stop valve from completely closing and resetting the RGSC circuit as documented in CR-806988 and CR-1172997.

The inspectors noted that, despite this internal operating experience, the ER-2003 evaluation completed in October 2022 (DPA -05-DI-2022-03614) did not consider possible degradation to the stop valve, resulting in a missed opportunity to develop actions to address this potential failure mode. Additionally, while the POD identified a long-term action to disassemble and inspect the Unit 1 stop valve, because this was not recognized as a potential failure mode caused by the steam leak on the steam supply valve, no actions were taken to monitor and address potential stem corrosion in the near term.

Corrective Actions: The licensee cleaned and lubricated the actuator and strokedthe stop valve multiple times until its performance improved. Maintenance applied grease to help lubricate the valve stem operator and to repel the leaking condensed steam from entering the drive mechanism. Subsequent testing following application of grease has shown improved performance of the HPCI turbine stop valve (FV15612) to fully close. The station is inspecting the valve weekly and has the option to apply grease, as needed, and this is tracked in the station schedule.

The licensee has an updated revision of the ACMP for monitoring conditions associated with the steam supply valve (HV155F001) leakage.

The licensee has planned corrective actions to replace the steam supply valve and overhaul the HPCI stop valve and hydraulic actuator in the next Unit 1 refueling outage.

Corrective Action References: CR-2023-06391

Performance Assessment:

Performance Deficiency: The licensee failed to identify and correct a condition adverse to quality associated with condensate accumulation in the HPCI system.

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, the licensee s failure to take appropriate corrective actions resulted in the loss of HPCI system operability when the sto p valve was rendered unable to fully close on April 7, 2023.

Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power. The inspectors performed a review of this finding using the guidance provided in IMC 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions, and determined this finding is of very low safety significance (Green) because the questions in Exhibit 2, Section A, were answered No.

Cross-Cutting Aspect: P.5 - Operating Experience: The organization systematically and effectively collects, evaluates, and implements relevant internal and external operating experience in a timely manner. Specifically, the licensee did not use the internal operating experience from 2006 and 2009 (CR-806988 and CR-1172997) in the ACMP, POD, and equipment reliability evaluation.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, states that measures shall be established to assure conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected. Contrary to the above, from October 10, 2022, through April 8, 2023, the licensee failed to take appropriate corrective actions associated with the Unit 1 HPCI system steam supply valve leakage. As a result, the HPCI stop valve developed corrosion products on the stem of the hydraulic cylinder and resulted in a loss of system operability on April 7, 2023.

The disposition of this finding closes LER 05000387/2023- 002-00, Unplanned lnoperability of the High-Pressure Coolant Injection (HPCI) System Due to Failure of the HPCI Turbine Stop Valve to Fully Close, Most Likely Due to Internal Corrosion and Mechanical Binding of the Valve Hydraulic Drive.

Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.

Inadequate Maintenance Procedure Resulted in Exceeding Secondary Containment Bypass Leakage Limit Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.3] - Change 71153 NCV 05000388 /2023004 -0 2 Management Open/Closed The inspectors determined a self-reveal ing Green finding and associated NCV of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, and TS 3.6.1.3, Action E1, occurred when the licensee operated with a penetration that exceeded the SCBL limit for longer than allowed by TS 3.6.1.3. Specifically, the feedwater inboard CIV,

241F010B, failed to pressurize during testing as a result of binding at the hinge pin to disc interface caused by insufficient side-to-side clearances due to the licensee s inadequate maintenance procedure.

Description:

The feedwater containment penetrations (X-9A and B) each have three CIVs that are leak-rate tested, and the minimum pathway leakage is included in the SCBL limit (TS Surveillance Requirement (SR) 3.6.1.3.11).

On March 26, 2023, the SCBL as - found minimum pathway leakage input from penetration X - 9B during the Unit 2 Spring 2023 refueling outage was 17,567 sccm, which exceeded the TS SR 3.6.1.3.11 combined leakage limit for all SCBL of 15 scfh (7,079 sccm).

Although there are three valves within the penetration, the primary contributor was associated with the feedwater inboard CIV, 241F010B, which failed to pressurize during testing as a result of binding at the hinge pin to disc interface caused by insufficient side-to-side clearances. The licensee determined that the maintenance procedure used to assemble the valve during the previous refueling outage, MT-GM- 003N, Inboard Feedwater Isolation Valves 141F010A/B and 241F010A/B Disassembly, Rework, and Reassembly, did not require verification of final (as - left) side-to-side clearances which resulted in the hinge pin being overtightened and subsequent binding of the valve disk. Additionally, the maintenance procedure and drawings were not coordinated to reflect historical engineering changes resulting in discontinuity between the documents, creating potential for assembly errors.

As a result, the inboard CIV failed to move freely preventing the test volume from pressurizing during local leak-rate testing. Based on the cause, this condition likely existed during the last operating cycle for longer than the 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> allowed by TS 3.6.1.3, Primary Containment Isolation Valves. Corrective maintenance was subsequently performed on all three valves,

and they were successfully leak-rate tested as the post-maintenance testing specified in the procedure and work order. Additionally, the licensee performed a calculation that concluded the condition would not result in a release that would exceed the dose limits for the control room and the public.

Corrective Actions: The key corrective actions included replacing the soft seats of the three CIVs and performing maintenance on the inboard CIV to ensure it closed freely and sealed properly. Planned actions include revising applicable valve maintenance procedures to require as-left hinge pin side-to-side clearance to be documented and confirmed to be within procedural values. Post - maintenance testing verified that the as - left SCBL was less than the limit required by TS SR 3.6.1.3.11.

Corrective Action References: CR-2023 - 05057

Performance Assessment:

Performance Deficiency: The maintenance procedure, MT-GM-003N, for 241F010B, was not adequate to ensure feedwater isolation valve, 241F010B, was reassembled properly. The maintenance procedure, MT-GM-003N, for 241F010B, did not require as-left hinge pin side-to-side clearance measurements be documented and confirmed to be within procedural values during reassembly.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Procedure Quality attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the feedwater inboard CIV, 241F010B, failed to pressurize during testing as a result of binding at the hinge pin to disc interface caused by insufficient side-to-side clearances due to the licensee s inadequate maintenance procedure.

As a result, feedwater penetration X-9B exceeded the TS SR 3.6.1.3.11 SCBL leakage limit.

Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix H, Containment Integrity Significance Determination Process.

The inspectors initially assessed the finding in accordance with IMC 0609, Appendix A, Exhibit 3, Barrier Integrity Screening Questions, and determined in consultation with Region I senior reactor analysts that the finding was related to containment isolation function that could represent an open pathway and impact large early release frequency. The inspectors determined this to be a Type B finding since it is related to a degraded condition that has potentially important implications for the integrity of the containment, without affecting the likelihood of core damage. Unit 2 is a boiling water reactor with a Mark II containment. The inspectors determined the finding is associated with an SSC (isolation valves) important to large early release frequency using Table 7.1, Phase 1 Screening - Type B Findings at Power, and determined a Phase 2 assessment is required. The inspectors determined this finding was of very low safety significance (Green) using Table 7.2, Phase 2 Risk Significance - Type B Findings at Power, because this issue involved containment leakage rates less than the values listed in Table 7.2. Specifically, containment leakage from the drywell to environment was not greater than 100 percent containment volume/day through containment penetration seals, isolation valves, or vent and purge systems.

Cross-Cutting Aspect: H.3 - Change Management: Leaders use a systematic process for evaluating and implementing change so that nuclear safety remains the overriding priority.

Specifically, the maintenance procedure and drawings were not coordinated to reflect historical engineering changes resulting in discontinuity between the documents, creating potential for assembly errors.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires in part that activities affecting quality shall be prescribed by procedures and drawings with appropriate acceptance criteria for determining that important activities have been satisfactorily accomplished. TS SR 3.6.1.3.11 requires the combined leakage rate for all SCBL paths is less than or equal to 15 scfh when pressurized to Pa. TS 3.6.1.3, Action E1, requires SCBL to be restored to below the limit within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> when the SCBL rate is not within limit.

Contrary to the above, since April 2021, licensee procedure MT-GM-003N, Inboard Feedwater Isolation Valves 141F010A/B and 241F010A/B Disassembly, Rework, and Reassembly, did not require side-to-side clearance measurements be confirmed against acceptance criteria to ensure proper valve reassembly. As a result, subsequent valve testing in March 2023 identified leakage exceeding the TS SR 3.6.1.3.11 SCBL limit.

The disposition of this finding closes LER 05000388/2023- 001-00, Secondary Containment Bypass Leakage Limit Exceeded Due to Inadequate Procedure Guidance Resulting in Failure of the Inboard Containment Isolation Valve to Close and Pressurize.

Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.

Minor Violation: Inadvertent Contact Between Relay Cover and Relay Trip 71153 Contacts Resulted in Automatic Actuation of the 'B' Emergency Diesel Generator On March 23, 2023, during overcurrent relay testing of the 2B engineering safeguards system (ESS) bus, the work group was reinstalling tested relay covers and inadvertently caused a 2B ESS bus lockout. Unit 2 was in Mode 5 for a refueling outage at the time. The described activity was performed during the division 2 electrical maintenance outage with d ivision 1 systems protected.

Following performance of critical relay calibrations for the B-phase bus differential relay, inadvertent contact was made between the target reset lever on the relay cover and the relay contacts during reinstallation of the relay cover. This resulted in a trip of the 86A12A20201 and 86A2A20201 4.16 KV bus 2B lockout relays. This immediately tripped all 4.16 KV breakers on the 2B ESS bus 2A202 and presented an undervoltage condition which caused a valid start signal to the 'B' emergency diesel generator. A prompt investigation was performed and determined that based on past successful performance, the station failed to mitigate the potential risk of this work to result in a bus lockout. The removal and reinstallation of the cover was not recognized as meeting critical step criteria, which contributed to the pre-job brief inadequately addressing specific mitigating actions. The identification of steps as critical steps ensures an additional barrier is established to mitigate the identified risk.

10 CFR Part 50, Appendix B, Criterion V, requires, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. The licensees administrative procedure for procedure adherence, NDAP-QA-0029, Procedure and Work Instruction Use and Adherence, requires that operating and maintenance procedures identify critical steps during task review or pre-job brief. NDAP -QA-0029 defines the critical step criteria for operating and maintenance procedures as a procedure step, series of steps, or action that, if performed improperly, will cause irreversible harm to plant equipment or people or significantly impact plant operations.

Contrary to the above, on March 23, 2023, the licensee failed to adequately implement licensee procedure NDAP-QA-0029. Specifically, the licensee failed to identify critical steps during task review or pre-job brief for the removal and reinstallation of the relay cover on the 2A202 ESS bus.

Screening: The inspectors determined the performance deficiency was of minor significance in accordance with the issue screening questions outlined in IMC 0612, Appendix B, Issue Screening Directions. The inspectors determined the performance deficiency did not adversely affect the Initiating Events or Mitigating Systems cornerstone objectives.

Specifically, the inadvertent lockout and de-energization of the 2B ESS bus did not result in the loss of SSCs required to maintain shutdown key safety functions and did not upset plant stability or challenge critical safety functions during shutdown operations.

Enforcement:

The licensee has taken corrective actions to restore compliance, including performing accountability per station procedures and planned procedure revisions to include continuous use checklists identifying removal and restoration work steps associated with relays that have the potential to trip protective devices. This failure to comply with CFR Part 50, Appendix B, Criterion V, constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy.

The disposition of this violation closes LER 05000387 and 05000388/2023- 001- 00, Inadvertent Contact Between Relay Cover and Relay Trip Contacts Resulted in Automatic Actuation of the 'B' Emergency Diesel Generator.

EXIT MEETINGS AND DEBRIEFS

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

• On October 16, 2023, the inspectors presented the requalification with pass/fail inspection results to Scott Yokimcus, Operations Requalification Programs Superintendent, and other members of the licensee staff.

• On October 19, 2023, the inspectors presented the emergency preparedness program inspection results to Derek Jones, Plant Manager, and other members of the licensee staff.

• On November 30, 2023, the inspectors presented the problem identification and resolution for the security CAP inspection results to Doug LaMarca, Strategic Planning Director, and other members of the licensee staff.

• On January 18, 2024, the inspectors presented the integrated inspection results to Derek Jones, Plant Manager, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Miscellaneous NDAP-00-1913 Seasonal Readiness, Attachment K Revision 17

71111.04 Drawings E106256 Unit 1 P&ID Residual Heat Removal Revision 72

71111.05 Fire Plans FP-1-RB-749 U1 Reactor Building - El. 749 Revision 0

71111.05 Fire Plans FP-1-TB-729 U1 Turbine Building - El. 729 Revision 0

71111.05 Fire Plans FP-2-RB-683-0 U2 Reactor Building - El. 683 Revision 0

71114.02 Procedures Susquehanna Steam Electric Station Alert and Notification June 2019

System (ANS) FEMA 350 Report

71114.04 Corrective Action Department 50.54Q Documentation and Formatting 10/18/2023

Documents Initiative (DI)

Resulting from 2023-16628

Inspection

71114.04 Procedures EP-102 Review, Revision, and Distribution of the SSES Emergency Revision 12

Plan and 50.54Q Evaluations

71114.05 Miscellaneous KLD TR - 1344 Susquehanna Steam Electric Station 2023 07/25/2023

Population Update Analysis

71114.05 Procedures Susquehanna Steam Electric Station Emergency Plan Revision 66

71114.05 Procedures EP-115 Equipment Important to Emergency Response (EITER) Revision 18

71152A Corrective Action CR-2020-16932, CR-2020-16935, CR-2020-17053,

Documents CR-2022-15148, CR-2023- 02505, CR-2023- 02849,

CR 2023- 02899, CR-2023- 05779, CR-2023- 06391,

CR 2023- 08446, CR-2023- 09925, CR-2023-11044,

CR 2023-14116, CR-2023-14241, CR-2023-14374,

CR 2023-14438, CR-2023-14776, CR-2023-15361,

CR 2023-15480, CR-2023-16185, CR-2023-16189,

CR 2023-16420, CR-2023-16801, CR-2023-17287,

CR 2023-17292, CR-2023-17607, CR-2023-18001,

CR 2023-18010

71152A Corrective Action CR-172997 Equipment Reliability Evaluation (ER)-2003: U1 HPCI Steam

Documents Isolation Valve Leakage

71152A Procedures LS-115-1001 Manual for Processing an AR or DPI Revision 1

71152A Procedures LS-120 Issue Identification and Screening Process Revision 15

71152A Procedures LS-125 Corrective Action Program Revision 15

Inspection Type Designation Description or Title Revision or

Procedure Date

71152A Procedures LS-125-1009 Trending Manual Revision 5

71152A Procedures NDAP-QA-0703 Operability Determinations and Functionality Assessments Revision 37

71152A Procedures NDAP-QA-0900 Conduct of Nuclear Security Revision 27

71152A Procedures NDAP-QA-1901 Station Work Management Process Revision 29

71152S Corrective Action CR-2023-10473, CR-2023-18217, CR-2023-07242,

Documents CR-2023-09535

71153 Corrective Action CR-2023-05057

Documents

19