IR 05000445/2025001

Integrated Inspection Report 05000445-2025001 and 05000446-2025001

ML25125A085
Person / Time
Site:	Comanche Peak
Issue date:	05/08/2025
From:	Ami Agrawal NRC/RGN-IV/DORS/PBB
To:	Peters K Vistra Operations Company
References
IR 2025001
Download: ML25125A085 (1)

Text

May 08, 2025

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT, UNITS 1 AND 2 -

INTEGRATED INSPECTION REPORT 05000445/2025001 AND 05000446/2025001

Dear Ken Peters:

On March 31, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Comanche Peak Nuclear Power Plant, Units 1 and 2. On April 15, 2025, the NRC inspectors discussed the results of this inspection with Chris Jackson, Site Vice President, 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. Two of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.

A licensee-identified violation which was determined to be of very low safety significance is documented in this report. We are treating this violation as a non-cited violation (NCV)

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 IV; the Director, Office of Enforcement; and the NRC Resident Inspector at Comanche Peak Nuclear Power Plant, 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 IV; and the NRC Resident Inspector at Comanche Peak Nuclear Power Plant, 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 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Ami N. Agrawal, Chief Reactor Projects Branch B Division of Operating Reactor Safety Docket Nos. 05000445 and 05000446 License Nos. NPF-87 and NPF-89

Enclosure:

As stated

Inspection Report

Docket Numbers:

05000445 and 05000446

License Numbers:

NPF-87 and NPF-89

Report Numbers:

05000445/2025001 and 05000446/2025001

Enterprise Identifier:

I-2025-001-0009

Licensee:

Vistra Operations Company, LLC

Facility:

Comanche Peak Nuclear Power Plant, Units 1 and 2

Location:

Glen Rose, TX

Inspection Dates:

January 1, 2025, to March 31, 2025

Inspectors:

J. Ellegood, Senior Resident Inspector

H. Strittmatter, Resident Inspector

M. Bloodgood, Senior Project Engineer

Approved By:

Ami N. Agrawal, Chief

Reactor Projects Branch B

Division of Operating Reactor Safety

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Comanche Peak Nuclear Power Plant,

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. A licensee-identified non-cited violation is documented in report section: 7115

List of Findings and Violations

Inoperable Turbine Driven Auxiliary Feedwater Pump During Mode Change to Mode 3 Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000445/2025001-01 Open/Closed

[H.5] - Work Management 71152A An NRC identified Green finding with an associated non-cited violation of LCO 3.0.4 occurred on November 17, 2024, when the licensee transitioned to Mode 3 with an inoperable turbine-driven auxiliary feedwater pump. Licensee staff observed that the motor to pump coupling for the turbine-driven auxiliary feedwater pump had not been installed following maintenance performed during a refueling outage. The observation occurred about 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> after entry into Mode 3.

Inadvertent Loss of All ANS Sirens Cornerstone Significance Cross-Cutting Aspect Report Section Emergency Preparedness Green NCV 05000445,05000446/2025001-02 Open/Closed

[P.3] -

Resolution 71152A A self-revealed Green finding and associated non-cited violation of 10 CFR 50.47(b)(5) and Part 50, appendix E.IV.D.3, was identified for an inadvertent loss of all alert and notification system sirens. During an unrelated test, the licensee noted that neither the primary nor the backup repeater was energized. One of these repeaters was needed to control the alert and notification system.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000445,05000446/20 24-001-00 Potential Loss of Safety Function Due to Inoperability of Both Trains of Uninterruptible Power Supply Heating, Ventilation

& Air Conditioning 71153 Closed LER 05000446/2024-001-01 Unit 2, Recurring Reactor Scrams associated with Main Feedwater System Modifications 71153 Closed

LER 05000446/2024-001-00 Unit 2, Two Recurring Reactor Scrams associated with Main Feedwater System Modifications 71153 Closed LER 05000445/2024-002-01 Unit 1, Condition Prohibited by Technical Specifications due to Inoperable Remote Shutdown System Functions 71153 Open LER 05000445/24-002-00 Unit 1, Condition Prohibited by Technical Specifications due to Inoperable Remote Shutdown System Functions 71153 Closed LER 05000446/2024002-01 Unit 2, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 3 71153 Closed LER 05000446/2024-002-00 Unit 2, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 3 71153 Closed

PLANT STATUS

Units 1 and 2 operated at or near rated thermal power for the entire 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

Impending Severe Weather Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather conditions prior to the onset of a winter storm on January 6 and 7, 2025:

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (4 Samples)

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

(1) Unit 1, instrument air system train B on January 13, 2025

(2) Unit 1, motor-driven turbine-driven auxiliary feedwater system train B on January 14, 2025

(3) Unit 2, safety chiller train B on February 11, 2025 (4)independent spent fuel storage installation dry cask storage on March 26, 2025

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 Samples)

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

(1) Unit 1, safeguards building pipe tunnel on February 4, 2025

(2) Unit 2, safeguards building pipe tunnel on February 4, 2025

(3) Unit 1, safeguards building 790 elevation corridors and containment spray chemical addition tank on March 20, 2025

(4) Unit 2, safeguards building 790 elevation corridors and containment spray chemical addition tank on March 20, 2025

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

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

(1) The inspectors observed and evaluated a simulator training session on January 28, 2025. The scenario started at 100 percent power and the crew responded to various plant transients including a circulating water pump trip, heater drain pump trip, loss of a 480-volt safety bus, faulted steam generator (feedwater side), and reactor coolant system leak.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (2 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)alternate power diesel generators (2)uninterruptable power supply heating, ventilation, and air conditioning system

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) Unit 2, yellow risk during emergent inoperability of the 2-06 safety chiller on February 10, 2025

(2) Units 1 and 2, emergent battery inoperability on February 13, 2025

(3) Unit 2, yellow risk due to emergency diesel generator 2-01 outage for jacket water leak repairs on March 10, 2025.

(4) Unit 2, yellow risk due to flow transmitter calibration for discharge of motor-driven auxiliary feedwater pump 2-01 on March 13, 2025.

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (8 Samples)

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

(1) Unit 2, containment sump with a small number of debris

(2) Unit 2, train B emergency diesel generator jacket water leak from keep warm pump shaft seal, condition report 2025-0166 (3)control room exhaust and filtration system train A makeup air supply fan, condition report 2025-0347 (4)fire suppression piping with internal corrosion (5)safety chiller 2-06 with full open component cooling water valve

(6) Unit 1, Gamma Metrics, condition report 2024-2119 (7)functionality of controls over very high radiation area associated with the new fuel elevator

(8) Unit 1, train B component cooling water with a leaking weld

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) (7 Samples)

(1)turbine-driven auxiliary feedwater pump to steam generator 1-01 flow control valve stroke time test after air operator calibration on January 30, 2025

(2) Unit 1, train A containment spray motor operated valves after major inspection on February 4, 2025 (3)safety-related batteries seismic remediation on February 20, 2025 (4)boric acid decontamination of valves on February 25, 2025

(5) Unit 2, train A component cooling water pump motor inspection on March 4, 2025, work order 23-315692

(6) Unit 1, letdown orifice line weld repair VT-2 and PT on March 5, 2025

(7) Unit 2, centrifugal charging pump 2-01 motor breaker testing on March 5, 2025, work order 23-323192

Surveillance Testing (IP Section 03.01) (1 Sample)

(1) Unit 2, motor-driven auxiliary feedwater pump 2-01 operability run on March 13, 2025

71114.06 - Drill Evaluation

Required Emergency Preparedness Drill (1 Sample)

(1)sitewide drill on March 19, 2025

Additional Drill and/or Training Evolution

The inspectors evaluated:

(1)table-top drill with the technical support center and emergency operations facility on February 27,

OTHER ACTIVITIES - BASELINE

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

IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01)===

(1) Unit 1 (January 1 through December 31, 2024)

(2) Unit 2 (January 1 through December 31, 2024)

IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (2 Samples)

(1) Unit 1 (January 1 through December 31, 2024)

(2) Unit 2 (January 1 through December 31, 2024)

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)

(1) Unit 1 (January 1 through December 31, 2024)

(2) Unit 2 (January 1 through December 31, 2024)

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) Loss of primary Alert and Notification System (ANS) sirens The inspectors reviewed the licensee's organizational effectiveness investigation and corrective action documents associated with an inadvertent loss of all ANS sirens that occurred on December 17, 2024. The licensee inadvertently deenergized the primary radio repeater for the ANS sirens due in large part to erroneous descriptions of the repeater in the work control documents as the backup radio repeater. The sirens were unavailable for approximately 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> and were restored within 30 minutes once discovered to be unavailable. The licensee attributed the incorrect work control documents in part to vague documentation in their EITER procedure. Licensee completed training with operations and county dispatch personnel to ensure the ability to quickly recover siren capability. Further planned corrective actions include a revision of the EITER procedure and staff guidelines to respond to a loss of ANS sirens. A green finding with an associated NCV is documented in this report.

(2) Mode change with inoperable turbine driven auxiliary feedwater pump The inspectors reviewed the licensee's cause analysis for a mode transition from mode 4 to mode 3 with an inoperable TDAFW pump. During a refueling outage, the licensee performed work activities on Unit 2 TDAFW. Following work completion, licensee staff did not understand the desired end state for the work. As a result, the licensee staff removed the clearance for the work then declared the pump operable despite the pump coupling not being installed. The licensee attributed the cause to an imprecise work instruction. A GREEN finding with an associated NCV is documented in this report.

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 05000445/2024-001-00, Potential Loss of Safety Function Due to Inoperability of Both Trains of Uninterruptible Power Supply Heating, Ventilation, and Air Conditioning (Accession No. ML24127A155). The inspection conclusions associated with this LER were documented in Inspection Report 05000445,05000446/2024001 as NCV 05000445,05000446/2024001-02. This LER is closed.

(2) LER 05000446/2024-001-01 and LER 05000446/2023-001-00, Two Recurring Reactor Scrams Associated with Main Feedwater System Modifications, (Accession No. ML24274A331). The inspection conclusions associated with this LER were documented in Inspection Report 05000445,05000446/2024003 as FIN 05000445,05000446/2024003-01 and FIN 05000445,05000446/2024003-02. This LER and updates are closed.

(3) LER 05000445/2024-002-01, Unit 1, Condition Prohibited by Technical Specifications due to Inoperable Remote Shutdown System Functions (ADAMS Accession No. ML24277A774). The inspection conclusions associated with this LER are documented in this report under Inspection Results section 71153. This LER is closed.

(4) LER 05000445/2024-002-00, Unit 1, Condition Prohibited by Technical Specifications due to Inoperable Remote Shutdown System Functions (ADAMS Accession No. ML24155A172). The inspection conclusions associated with this LER are documented in this report under Inspection Results section 71153. This LER and updates are closed.

(5) LER 05000446/2024-002-01, Unit 2, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 3 (ADAMS Accession No. ML25044A064). The inspection conclusions associated with this LER are documented in this report under Inspection Results section 71152. This LER and updates are closed.

(6) LER 05000446/2024-002-00, Unit 2, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 3 (ADAMS Accession No. ML25016A035). The inspection conclusions associated with this LER are documented in this report under Inspection Results section 71152. This LER is closed.

INSPECTION RESULTS

Inoperable Turbine Driven Auxiliary Feedwater Pump During Mode Change to Mode 3 Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000445/2025001-01 Open/Closed

[H.5] - Work Management 71152A An NRC identified Green finding with an associated non-cited violation of LCO 3.0.4 occurred on November 17, 2024, when the licensee transitioned to Mode 3 with an inoperable turbine-driven auxiliary feedwater pump. Licensee staff observed that the motor to pump coupling for the turbine-driven auxiliary feedwater pump had not been installed following maintenance performed during a refueling outage. The observation occurred about 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> after entry into Mode 3.

Description:

During 2RF21 outage, the licensee conducted maintenance on the 2-01 turbine-driven auxiliary feedwater (TDAFW) pump. As part of the maintenance, the licensee removed the coupling between the pump and motor. Following completion of the planned work, the workers signed off the clearance associated with the maintenance. Some members of licensee staff believed that an uncoupled run would be performed prior to mode ascension; therefore, the coupling did not need to be installed prior to signing off of the clearance.

Operations staff, unaware that the coupling was not installed, considered the pump to be operable based on documentation of completion of planned maintenance.

LCO 3.0.4 prohibits entry into a Mode where the LCO is applicable with some exceptions. None of the exceptions in the LCO applied. However, since the licensee did not recognize the status of the auxiliary feedwater (AFW) pump, the licensee entered mode 3 with the TDAFW pump inoperable. Licensee and resident inspector review of the circumstances identified that actions by the operations staff could have readily identified that the TDAFW was not operable prior mode ascension. The inspectors noted that SR 3.0.1 bases states, in part, "Post maintenance testing may not be possible in the current MODE or other specified conditions in the Applicability due to the necessary unit parameters not having been established. In these situations, the equipment may be considered OPERABLE provided testing has been satisfactorily completed to the extent possible and the equipment is not otherwise believed to be incapable of performing its function. This will allow operation to proceed to a MODE or other specified condition where other necessary post maintenance tests can be completed." In this case, a visual check would have revealed that the pump was not operable.

Following identification of the issue, the licensee declared the TDAFW pump inoperable.

However, the licensee did not elevate plant risk to Yellow. After discussion with the inspectors, the licensee determined elevation to Yellow was warranted and took the appropriate actions.

Corrective Actions: The licensee installed the pump coupling, entered yellow risk, and performed a post maintenance test.

Corrective Action References: CR-2024-7205

Performance Assessment:

Performance Deficiency: The licensee declared the Unit 2 TDAFW pump operable following maintenance while shutdown prior to installation of the coupling between the pump motor and pump.

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. The licensee left the TDAFW in a condition that prevented it from being able to perform its mission.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using IMC 0609, appendix A, exhibit 2, the inspectors answered no to all the questions, therefore, the finding screened as Green.

Cross-Cutting Aspect: H.5 - Work Management: The organization implements a process of planning, controlling, and executing work activities such that nuclear safety is the overriding priority. The work process includes the identification and management of risk commensurate to the work and the need for coordination with different groups or job activities. The licensee failed to provide a work instruction with sufficient clarity such that workers knew the desired end state of the TDAFW. In addition, the planning failed to ensure coordination between maintenance and operations.

Enforcement:

Violation: Limiting Condition for Operation 3.0.4 requires, "When an LCO is not met, entry into a MODE or other specified condition in the Applicability shall only be made:

a.

When the associated ACTIONS to be entered permit continued operation in the MODE or other specified condition in the Applicability for an unlimited period b.

After performance of a risk assessment addressing inoperable systems and components, consideration of the results, determination of the acceptability of entering the MODE or other specified condition in the Applicability, and establishment of risk management actions, if appropriate; exceptions to this specification are stated in the individual specifications, or c.

When an allowance is stated in the individual value, parameter, or other specification.

This specification shall not prevent changes in MODES or other specified conditions in the applicability that are required to comply with ACTIONS or that are part of a shutdown of the unit.

None of the conditions in LCO 3.0.4 apply. Therefore, contrary to this requirement, on November 17, 2024, the licensee entered mode 3 with an inoperable TDAFW pump.

LCO 3.7.5 is applicable in mode 3 and requires three trains of AFW to be operable for operation for an unlimited period. Only two trains of AFW were operable at the time of mode ascension.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Inadvertent Loss of All ANS Sirens Cornerstone Significance Cross-Cutting Aspect Report Section Emergency Preparedness Green NCV 05000445,05000446/2025001-02 Open/Closed

[P.3] -

Resolution 71152A A self-revealed Green finding and associated non-cited violation of 10 CFR 50.47(b)(5) and Part 50, appendix E.IV.D.3, was identified for an inadvertent loss of all alert and notification system sirens. During an unrelated test, the licensee noted that neither the primary nor the backup repeater was energized. One of these repeaters was needed to control the alert and notification system.

Description:

The licensees primary alert and notification system (ANS) method is a network of sirens combined with emergency alert system (EAS) via AM radio. In an emergency, the siren sounding tells the public to tune into a specific radio station for information and instructions. The backup ANS method is route alerting and an emergency telephone notification system (e.g. Reverse 911, Code Red).

A work order for an unrelated site project required that the primary ANS radio repeater be deenergized and moved to another cabinet. However, the supporting documentation for the work order such as the engineering advanced work authorization (AWA) and the operations impact form erroneously described the repeater to be the backup repeater for ANS. Thus, to each internal organization the work order appeared to be removing power from the backup repeater and so would not require switching from the primary to backup repeater.

On December 17, 2024, at approximately 0900 the primary repeater was deenergized for planned work on the sites radio system. Since the backup repeater was deenergized as well the sirens could not be activated therefore causing a loss of all ANS sirens.

On December 18, 2024, at 1430, during planned maintenance on the sirens the licensee discovered a loss of all communications with the sirens and that the primary repeater was not working. At 1500, the licensee energized the backup repeater restoring ANS capability. The sirens were unavailable for a total of approximately 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> and upon discovery the licensee restored sirens within about 30 minutes.

During this time, the backup ANS method remained available. The emergency planning zone population enrolled for reverse 911 is approximately 77 percent and the system can notify all enrollees within about 15 minutes.

The licensee had previously correctly identified the primary repeater in corrective action documents. Also, during an audit of emergency preparedness, the licensee documented the need to revise the equipment important to emergency response (EITER) procedure such that it is clear which repeater is the primary ANS repeater, and which is the backup as well as the need for written guidance on activities required during planned or unplanned loss of the primary repeater (TR-2021-8145). This lack of clarity contributed to the erroneous description of the primary repeater as the backup repeater in the aforementioned work order.

Corrective Actions: The licensee restored power to the primary repeater, conducted training with operations staff and county dispatchers on proper action should a loss of sirens be discovered. A condition report was generated to track more corrective actions going forward.

Corrective Action References: CR-2024-007809

Performance Assessment:

Performance Deficiency: Incorrectly identifying the primary repeater as the backup repeater in the evaluation and impact of the work order was a performance deficiency. The licensee expects that work control documents correctly and clearly identify the components to be worked and evaluate the impact of that work on the site.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Facilities and Equipment attribute of the Emergency Preparedness cornerstone and adversely affected the cornerstone objective to ensure that the licensee is capable of implementing adequate measures to protect the health and safety of the public in the event of a radiological emergency.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix B, Emergency Preparedness SDP. Specifically, Table 5.5-1 Significance Examples 50.47(b)(5) and Attachment 2 Failure to Comply Significance Logic. Considering the relatively short duration of siren outage (30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />), the time to restore ANS capability (30 minutes), and the large coverage and speed of the prearranged backup capability with reverse 911, the inspectors determined that the RSPS function was not degraded and therefore represented a very low safety significance (Green).

Cross-Cutting Aspect: P.3 - Resolution: The organization takes effective corrective actions to address issues in a timely manner commensurate with their safety significance. Specifically, the licensee had previously documented the need for creating written guidance for activities related to planned and unplanned loss of the primary siren repeater as well as clarifying the description of the radio repeaters in the EITER procedure but did not implement those changes.

Enforcement:

Violation: 10 CFR 50.54 (q)(2) requires, in part, that licensees follow and maintain an emergency plan that meets the requirements of Appendix E and 50.47(b). 10 CFR 50.47(b)(5) and appendix E.IV.D.3 require, in part, that the licensees ANS shall have the capability to essentially complete the initial alerting and initiate notification of the public within about 15 minutes. Contrary to the above, from December 17 through 18, 2024, approximately 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, the licensees primary ANS method did not have the capability to essentially complete the initial alerting and initiate notification of the public within about 15 minutes.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Licensee-Identified Non-Cited Violation 71153 This violation of very low safety significance was identified by the licensee and has been entered into the licensee corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Violation: 10 CFR 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established for the selection and review for suitability of application of materials, parts, equipment, and processes that are essential to the safety related function of the structures, systems, and components. Contrary to the above, on or about June 11, 2011, through April 18, 2024, the licensee failed to review the suitability of application of parts that are essential to the safety related function of the Gamma Metrics neutron flux monitoring system. Specifically, the operating characteristic for a modified power supply did not support operational continuity following a loss of power.

Significance/Severity: Green. Because Gamma Metrics does not have a risk significant PRA functionality, the inspectors answered "No" to all the questions in exhibit 2 of IMC 0609, appendix A, therefore the finding screens as Green.

Corrective Action References: CR-2024-002119

EXIT MEETINGS AND DEBRIEFS

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

• On April 15, 2025, the inspectors presented the integrated inspection results to Chris Jackson, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

M1-0206

Flow Diagram Auxiliary Feedwater System

CP-21

M1-0206-01

Flow Diagram Auxiliary Feedwater System, Pump Trains

CP-19

M1-0206-02

Flow Diagram Auxiliary Feedwater System Yard Layout

CP-22

M1-0216

Flow Diagram Compressed Air System

CP-48

M1-0216-01

Flow Diagram Instrument Air Supply Electrical and Control

CP-28

M1-0216-A

Flow Diagram Compressed Air System

CP-42

M1-0216-B

Flow Diagram Compressed Air System

CP-23

Drawings

M1-0216-C

Flow Diagram Compressed Air System

CP-12

Instrument Air System Big Book

09/08/2014

Aux Feedwater Big Book

07/01/2011

Miscellaneous

DBD-ME-0218

Unit 1 and 2 Design Basis Document

OPT-206A

Auxiliary Feedwater System (AFW) Train B

SOP-304A-AF-

V02

Train B MD Auxiliary Feedwater Pump Lineup

71111.04

Procedures

SOP-509A

Instrument Air System Operating Procedure Manual

FPI-102A

Unit 1 Safeguards Building Elevation 790'-6"

71111.05

Procedures

FPI-102B

Unit 2 Safeguards Building Elevation 790'-0"

CR-YYYY-NNNN

24-003199, 2024-1448, 2024-0824

Corrective Action

Documents

TR-YYYY-NNNN

24-005600, 2020-005366

Engineering

Evaluations

EV-CR-2025-

000824-2

Maintenance Rule Evaluation for APDG loose amphenol

connections

Miscellaneous

DE190439 THRU

DE190442

Vendor Document for APDGs

10/13/2019

STA-677

Preventive Maintenance Program

71111.12

Procedures

STA-748

Equipment Reliability Process

CR-YYYY-NNNN

23-5454, 2024-6772, 2024-6773, 2024-005544,

24-005675, 2025-000680, 2025-000832, 2025-000914,

25-0166, 2025-0347

Corrective Action

Documents

TR-YYYY-NNNN

25-1439

71111.15

Engineering

Evaluations

EV-2011-001192-

Technical Evaluation of Replacement Item

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

Miscellaneous

Supplier Disposition Request for Gamma Metrics Power

Supply 201401-101

06/16/2011

OPT-210

Control Room HVAC System

SOP-609B

Diesel Generator System

Procedures

STI-422.01

Operability Determination and Functionality Assessment

Program

Work Orders

WO

23-192517

Engineering

Evaluations

25-106518

Repair letdown line

03/05/2025

MSE-P0-8349

Limitorque Actuator Periodic Electrical and Mechanical

Inspection

ODA-407-8

CP24-1064 Valve Strokes

2/04/2025

Procedures

OPT-206

AFW System

24-618604

MDAFW Pump 2-01 Run

03/13/2025

25-106518

Weld Repair Letdown Orifice Line

03/05/2025

71111.24

Work Orders

WO

25-10326, 25-22903, 25-72285, 25-72314, 25-72322

CPNPP ERO Blue Team Exercise

03/19/2025

71114.06

Miscellaneous

25 ERO Tabletop Scenario

February

25

CR-YYYY-NNNN

2005-4962, 2024-7809, 2025-000657

Corrective Action

Documents

TR-YYYY-NNNN

21-8145

Comanche Peak Nuclear Power Plant Alert and Notification

System Design Report

ANS Outage Organizational Effectiveness Evaluation

Miscellaneous

EV-CR-2023-

007273-1

Evaluation for Gamma Metrics Power Supply Trip During

Integrated Test Sequence

71152A

Work Orders

WO

23-253587, 24-433024, 24-364732, 23-244919, 23-457808,

5984117