IR 05000237/2024002

Integrated Inspection Report 05000237/2024002 and 05000249/2024002

ML24227A058
Person / Time
Site:	Dresden
Issue date:	08/14/2024
From:	Robert Ruiz NRC/RGN-III/DORS/RPB1
To:	Rhoades D Constellation Energy Generation
References
IR 2024002
Download: ML24227A058 (1)

Text

SUBJECT:

DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3-INTEGRATED INSPECTION REPORT 05000237/2024002 AND 05000249/2024002

Dear David Rhoades:

On June 30, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Dresden Nuclear Power Station, Units 2 and 3. On July 24, 2024, the NRC inspectors discussed the results of this inspection with H. Patel, Plant General Manager, and other members of your staff. The results of this inspection are documented in the enclosed report.

Four findings of very low safety significance (Green) are documented in this report. Four 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 III; the Director, Office of Enforcement; and the NRC Resident Inspector at Dresden Nuclear Power Station, Units 2 and 3.August 14, 2024 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 III; and the NRC Resident Inspector at Dresden Nuclear Power Station, Units 2 and 3.

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, Robert Ruiz, Chief Reactor Projects Branch 1 Division of Operating Reactor Safety Docket Nos. 05000237 and 05000249 License Nos. DPR19 and DPR25

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000237 and 05000249

License Numbers: DPR-19 and DPR-25

Report Numbers: 05000237/2024002 and 05000249/2024002

Enterprise Identifier: I2024002-0059

Licensee: Constellation Energy Generation, LLC

Facility: Dresden Nuclear Power Station, Units 2 and 3

Location: Morris, IL

Inspection Dates: April 01, 2024 to June 30, 2024

Inspectors: Z. Helgert, Acting Resident Inspector M. Porfirio, Illinois Emergency Management Agency C. St. Peters, Senior Allegations Specialist J. Steffes, Senior Resident Inspector

Approved By: Robert Ruiz, Chief Reactor Projects Branch 1 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 Dresden Nuclear Power Station,

Units 2 and 3, 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: 71152S.

List of Findings and Violations

Failure to Follow Procedure Resulting in Voiding in Unit 2 High Pressure Coolant Injection System Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71152A Systems NCV 05000237,05000249/202400201 Conservative Open/Closed Bias A self-revealed finding of very low safety significance (Green) and an associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified for the licensees failure to perform activities affecting quality in accordance with documented instructions appropriate for the circumstances associated with the Unit 2 high pressure coolant injection (HPCI) system.

Specifically, the licensee failed to perform a fill and vent of the HPCI system following high and low-pressure surveillance runs by incorrectly marking the step as N/A, which contributed to a void in the system and adversely impacted its availability and reliability.

Fire Barrier Impaired Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.12] - Avoid 71152A NCV 05000237,05000249/202400202 Complacency Open/Closed The inspectors identified a finding of very low safety significance (Green) and an associated non-cited violation (NCV) of Technical Specifications 5.4.1.c, Fire Protection Program Implementation, for the licensees failure to implement procedures associated with fire barriers. Specifically, the licensee failed to implement step G.4.C of procedure DFPP 417501,

Fire Barrier Integrity and Maintenance, Revision 25, and prevented a fire door from automatically closing as required and rendering the barrier non-functional when a roll of duct tape was used to prop the door open during maintenance on a fire detection system.

2/3 Emergency Diesel Generator Output Breaker Opened During Surveillance Testing Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [P.2] - 71152A Systems NCV 05000237,05000249/202400203 Evaluation Open/Closed A finding of very low safety significance (Green) was self-revealed for the licensees failure to identify a condition adverse to quality. Specifically, upon discovering in 2020 that procedure DIP 210028, Banana Jack Adapter Installation, had deficient instructions for securing the banana jacks, the licensee failed to identify whether any safety-related/risk-significant components still had banana jacks installed without design-verified torque. As a result, the licensee failed to identify that the banana jacks, and therefore the control circuitry wiring on the 2/3 emergency diesel generator (EDG), were loose until the EDG failed during surveillance testing on January 30, 2023.

Failure to Properly Implement Fire Impairment Procedure Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.12] - Avoid 71152S NCV 05000237,05000249/202400204 Complacency Open/Closed The inspectors identified a finding of very low safety significance (Green) and associated non-cited violation (NCV) of Technical Specification 5.4.1c, when the licensee failed to follow a step in procedure OPAA201007, Fire Protection Impairment Control. Specifically, during a period when a continuous fire watch was required to compensate for an inoperable detection and suppression system, the licensee failed to ensure the fire watch would implement step 3.5.4 of procedure OPAA201007, Fire Protection Impairment Control, in its entirety. The licensee failed to ensure the continuous fire watch would attempt to extinguish the fire in accordance with step 3.5.4.

Additional Tracking Items

None.

PLANT STATUS

Unit 2 began the inspection period at rated thermal power. On April 5, 2024, power was reduced to approximately 82 percent to perform scram valve maintenance. The unit returned to rated thermal power the next day. On April 12, 2024, power was reduced to approximately 81 percent to perform scram valve maintenance. The unit returned to rated thermal power the next day. On April 19, 2024, power was reduced to approximately 80 percent to perform scram valve maintenance. The unit returned to rated thermal power the next day. On April 26, 2024, power was reduced to approximately 80 percent to perform scram valve maintenance. The unit returned to rated thermal power the next day. On May 17, 2024, power was reduced to approximately 64 percent to perform rod sequence exchange and scram valve maintenance.

The unit returned to rated thermal power the next day and remained at or near rated thermal power for the remainder of the inspection period.

Unit 3 began the inspection period at rated thermal power. On May 10, 2024, power was reduced to approximately 79 percent to perform rod sequence exchange and scram valve maintenance. The unit returned to rated thermal power the next day 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, observed risk-significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

71111.01 - Adverse Weather Protection

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

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of extreme hot weather for the following systems:

Service water and circulating water, reactor building closed cooling water, turbine building closed cooling water, and auxiliary electrical equipment room heating, ventilation, and cooling (HVAC), on May 29-June 3, 2024

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 associated with high winds and possible tornadic activity on April 16, 2024

71111.04 - Equipment Alignment

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

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

(1) Unit 2 A core spray system on April 2, 2024

(2) Unit 3 high pressure coolant injection (HPCI) system on April 10-11, 2024

(3) 2/3 emergency diesel generator (EDG) system while the Unit 3 EDG was unavailable for work window on April 22, 2024

(4) 2/3 standby gas treatment system train B while the A train was unavailable for maintenance on May 14, 2024

(5) Unit 3 B core spray while B train of low pressure coolant injection (LPCI) was inoperable for maintenance on May 20-21, 2024

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (8 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) Fire Zone (FZ) 9.0C Unit 2/3 swing diesel generator room elevation 517' on April 17, 2024

(2) FZ 1.1.1.2 Unit 3 reactor building ground floor elevation 517' on April 18, 2024

(3) FZ 11.2.3 Unit 2 HPCI pump room elevation 476' on April 18, 2024

(4) FZ 11.1.2 Unit 3 southeast corner room elevation 476' on April 18, 2024

(5) FZ 8.2.5A Unit 2 trackway, reactor feed pump room, condensate transfer pump and switchgear areas elevation 517' on May 15, 2024

(6) FZ 8.2.5C Unit 2 lube oil room, Unit 2/3 electro-hydraulic reservoir and condensate demineralizer areas elevation 517' on May 15, 2024

(7) FZ 8.2.5.E Unit 3 trackway, reactor feed pump room, condensate transfer pump and switchgear areas elevation 517' on May 15, 2024

(8) FZ 11.3, Unit 2/3 circulating water pumps elevation 490', Unit 2/3 service water pumps/traveling screens elevation 509', and Unit 2/3 crib house ground floor elevation 517' on May 17, 2023

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the: Unit 2 and Unit 3 torus basements, southeast and southwest corner rooms.

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 between May 22, 2024, and June 21, 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 planned down power for rod sequence exchange, rod recovery, and control rod drive testing on April 5-6, 2024.

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) 4kV circuit breakers due to failures

(2) Incore monitoring, specifically local power range monitoring

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (7 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 3 (U3) elevated fire risk blue due to planned work window on U3 LPCI division I system, on April 89, 2024

(2) Unit 3 emergent work on the 3A core spray 4kV breaker, elevated fire risk blue due to planned surveillance on the U3 division I and division II LPCI emergency core cooling system (ECCS) loop select circuity logic system functional test, and planned maintenance on the 125V battery charger 3A, on May 810, 2024

(3) Unit 2 (U2) aggregate plant risk and elevated fire risk blue due to planned work window on the U2 division II LPCI and division II containment cooling service water (CCSW), on May 1416, 2024

(4) Unit 3 aggregate plant risk and elevated fire risk blue due to planned work window on the U3 division II LPCI and division II CCSW, on May 21, 2024

(5) Unit 2 elevated risk due to 2B adjustable speed drive optical link module replacement at full power, on May 23, 2024

(6) Unit 2 emergent work due to air start motor issue occurring during monthly emergency diesel generator run, on June 10, 2024

(7) Unit 3 emergent work due to unplanned half scram on the B Reactor Protection System (RPS) channel, on June 12, 2024

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)

The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:

(1) Unit 3 LPCI loop closed cooling service water pump 3A discharge check valve back leakage as documented in CR 4764162

(2) Bus 22 main feed breaker spring position indication showing between charged and discharged as documented in CR 4770320

(3) Unit 2 alternate battery potential impacts due to incorrect water addition and being placed on equalizing charge as documented CR 4771001

(4) Unit 3 local power range monitor 2409C bypassed as documented in CR 4775905

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) (4 Samples)

(1) 2/3 EDG PMT following planned maintenance, on March 2527, 2024

(2) Unit 3 EDG PMT testing following planned maintenance, on April 21 -26, 2024

(3) Unit 3 LPCI PMT following planned maintenance, on May 19 - 22, 2024

(4) Unit 2 EDG PMT following emergent work due to a failure of the air start motor, on June 10, 2024

Surveillance Testing (IP Section 03.01) (5 Samples)

(1) DIS 150005, Unit 2 Division I and II LPCI ECCS Initiation Circuitry Logic System Functional Test, on April 3, 2024

(2) DIS 026305, Unit 2 ATWS RPT/ARI and ECCS Level MTU and STU Channel Functional Test, on April 25, 2024

(3) DOS 660001, Unit 3 EDG Surveillance Tests, per Work Order (WO) 5521154

(4) DIS 050002, Unit 2 Reactor Vessel Low Water Level Scram and Low Low Water Level Isolation MTU/STU Channel Calibration and Functional Test, on May 5, 2024

(5) DIS 130007, Unit 3 Isolation Condenser Steam/Condensate Line High Flow Calibration, on June 28, 2024

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

(1) DOS 110004, Unit 2 2B Standby Liquid Control System Quarterly/Comprehensive Pump Test for the Inservice Testing (IST) Program, on May 15, 2024

71114.06 - Drill Evaluation

Required Emergency Preparedness Drill (1 Sample)

(1) Emergency preparedness drill on June 25, 2024

Additional Drill and/or Training Evolution (1 Sample)

The inspectors evaluated:

(1) Focus area drill on May 2,

OTHER ACTIVITIES-BASELINE

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) Evaluation and corrective actions for the Unit 2 HPCI void that rendered HPCI inoperable, as documented in action report (AR) 4718861

(2) Evaluation and corrective actions associated with the impairment of the Unit 2 EDG fire door as documented in CR 4765553

(3) 2/3 EDG output breaker opened during surveillance testing as documented in CR 4551179

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

(1) The inspectors reviewed the licensees corrective action program to identify potential trends in implementation of the fire protection program that might be indicative of a more significant safety issue. In particular, the inspectors reviewed the licensees implementation of transient combustible controls and fire watch implementation.

71153 - Follow-Up of Events and Notices of Enforcement Discretion Reporting (IP Section 03.05)

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

(1) LER 237/2023001-00, HCPI Inoperable Due to Air Void Accumulation (ADAMS Accession No. ML24019A030)

This LER was submitted and subsequently retracted by licensee correspondence titled Retraction of Licensee Event Report 237 /2303001-00, HPCI Inoperable Due to Air Void Accumulation, dated May 8, 2024, (ADAMS Accession No. ML24134A113).

This LER is Closed.

OTHER ACTIVITIES

-TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

92709 - Licensee Strike Contingency Plans Licensee Strike Contingency Plans

(1) On January 27, 2024, at midnight, the contract between the Service Employees International Union (SEIU) Local 1, who represent Dresden security officers, and Constellation expired. In preparation for a potential strike/lockout, the NRC inspectors evaluated the adequacy of the licensees contingency plan. The inspectors assessed the adequacy of the strike/lockout staffing levels, staff training and qualifications, safety-conscious working environment, and site access in meeting operational and security requirements.

Upon expiration of the contract, the employees continued to staff the regulatory required positions while negotiations were in progress. During the period without a contract, the NRC inspectors evaluated the adequacy of the licensees implementation of its contingency plan. The inspectors assessed:

1. The continuity of security force operation 2. Plant operations, minimum staffing requirements, safety-conscious working environment, and site access

On May 10, 2024, a ratified contract between the SEIU Local 1, which represents Dresden security officers, and Constellation was reached.

INSPECTION RESULTS

Failure to Follow Procedure Resulting in Voiding in Unit 2 High Pressure Coolant Injection System Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71152A Systems NCV 05000237,05000249/202400201 Conservative Open/Closed Bias A self-revealed finding of very low safety significance (Green) and an associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified for the licensees failure to perform activities affecting quality in accordance with documented instructions, appropriate for the circumstances, associated with the Unit 2 high pressure coolant injection (HPCI)system. Specifically, the licensee failed to perform a fill and vent of the HPCI system following high and low-pressure surveillance runs by incorrectly marking the step as N/A, which contributed to a void in the system and adversely impacted its availability and reliability.

Description:

On November 20, 2023, at 9:56 a.m. an air void was found in the Unit 2 HPCI discharge piping while monthly non-destructive examination (NDE) ultrasonic testing (UT) was being performed. The void was determined to be larger than allowable. The site declared HPCI inoperable and made an 8-hour reportability call due to a condition that could impact the safety function of a single train safety system. Venting was performed, and the system was restored to operable at 10:34 a.m. that same day. The site initiated a corrective action program evaluation (CAPE) and submitted a Licensee Event Report (LER).

During the Unit 2 2023 refueling outage (D2R28), water side work was performed, which included draining portions of the feedwater injection side of HPCI. On November 14, following the completion of the work, HPCI was filled and vented in accordance with procedure DOP 230001, High Pressure Coolant Injection (HPCI) System Standby Operation, Revision 60. NDE UT was performed, and the results were documented indicating pipe conditions adjacent to the high point vents as filled and vented.

On November 16, HPCI was started and ran for low-pressure surveillance testing per DOS 230003, High Pressure Coolant Injection System Operability and Quarterly IST Verification Test Revision 120. No additional venting was performed, per step I.7.y. Later, on November 16, HPCI was started and ran for high pressure surveillance per DOS 230003. No additional venting was performed per step I.7.y. Step I.7.y in DOS 230003 was a conditional step stating, IF this surveillance has been run as a post-maintenance test after HPCI system maintenance where the system was partially OR fully drained, THEN perform a fill and vent of the discharge piping downstream of the MO 2(3)-23019, PP DISCH VLV, per DOP 230001.

The licensee determined that this step was not applicable and did not perform it.

On November 20, monthly emergency core cooling system UT and venting were commenced. Air was discovered in the U2 HPCI High Point Vent. NDE identified the horizontal pipe run had no indication of water, and the vertical pipe runs on each side had a water solid signal. Previously, a gas void acceptance criteria of 2.67 ft3 had been established.

The void found was calculated to be approximately 22 ft3, which exceeded the acceptance criteria at the time. LCO 3.5.1 Condition G was entered by the shift, and operations vented the portion of HPCI piping per DOS 140007, ECCS Venting Revision 38. 90 seconds of air/ air-water mixture was observed during venting activities. The location was then verified as filled via UT examination, LCO 3.5.1 was exited, and HPCI declared operable that same day.

The sites CAPE reviewed six potential scenarios: improper draining of the HPCI piping beyond the boundary scope, post-maintenance testing (PMT) sequence and valves changing position after venting, excessive venting, degassing, leakage from feedwater lines, and NDE report or UT device not accurate. The cause was identified as the air voiding was caused by less than adequate procedure guidance to direct an additional fill and vent after surveillance testing was performed. The licensee interviews with the crew identified that the step was marked N/A due to the successful post fill and vent NDE. The site identified that senior reactor operators and reactor operators did not validate this conditional step correctly as a contributing cause. In addition, the outage schedule did include a line item for NDE to perform additional UT as required, but NDE was not contacted due to the step being marked as N/A.

An extent of condition was also performed as part of the CAPE. The extent of condition identified that following D2R28, a void was found in the 2A core spay on November 22, 2023.

Investigation into the cause continues as the extent of condition found that 2A core spray was vented following a surveillance run, and NDE found the system to be water solid.

On April 4, 2024, the site completed an acceptance review of calculations from Sargent and Lundy to demonstrate the void of approximately 22 ft3 would not render the Unit 2 HPCI system inoperable. That calculation along with the LER retraction was reviewed by the NRC in section 71153 of this report. In addition, the site reclassified the IR, withdrew the CAPE, and replaced it with a work group evaluation.

Corrective Actions: The licensee performed a prompt investigation, evaluated the event via causal product, created an action item to ensure the outage activity for HPCI run includes a note to perform step I.7.y of procedure DOS 230003, and created a corrective action to revise procedure DOS 230003 to direct that the HPCI runs during outages must have venting performed afterward.

Corrective Action References: AR 4718861, Air Void Identified U2 HPCI During 1M Periodic Verification

Performance Assessment:

Performance Deficiency: Procedure DOS 230003, High Pressure Coolant Injection System Operability and Quarterly IST Verification Test, was implemented by the licensee to demonstrate operability and the operational readiness of components including, but not limited to, the HPCI pump and subsystem components, per Dresden Station Technical Specifications and Inservice Testing Program. Step I.7.y was a conditional step stating, IF this surveillance has been run as a post-maintenance test after HPCI system maintenance where the system was partially OR fully drained, THEN perform a fill and vent of the discharge piping downstream of the MO 2(3)-23019, PP DISCH VLV, per DOP 230001.

The inspectors concluded that the licensees failure to follow and incorrectly N/A the step, resulted in the failure to recognize the need to perform a fill and vent following surveillance testing, allowed a void to form that was bigger than the acceptance criteria at the time and challenged system availability/reliability. Additionally, the inspectors concluded that this failure constituted a performance deficiency that was within the licensees ability to have foreseen and that should have been prevented.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human 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 staffs failure to recognize the need to perform a fill and vent, and incorrectly N/A step I.7.y of DOS 230003 resulted in an adverse impact to the Unit 3 HPCI systems availability and reliability. Additionally, inspectors reviewed minor examples of IMC 0612 Appendix E, Examples of Minor Issues, issue date October 26, 2023, and determined that example 3.f was applicable. Specifically, in order to justify the as-found condition of the HPCI void during monthly surveillance the licensee revised calculations in order to establish operability and functionality.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors answered yes to question A.1 in Exhibit 2 Mitigating Systems Screening Questions and determined the finding to be of very low safety significance (i.e., Green).

Cross-Cutting Aspect: H.14 - Conservative Bias: Individuals use decision-making practices that emphasize prudent choices over those that are simply allowable. A proposed action is determined to be safe in order to proceed, rather than unsafe in order to stop. Specifically, the licensee staff did not verify that the conditional step in DOS 230003, step I.7.y, could be marked as N/A, and incorrectly assumed the step could credit the successful NDE performed prior to the surveillance runs.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires, in part, that activities affecting quality be prescribed by documented procedures of a type appropriate to the circumstances and be accomplished in accordance with these procedures. The licensee established procedure DOS 230003, High Pressure Coolant Injection System Operability and Quarterly IST Verification Test, Revision 120, as the implementing procedure for demonstrating operability and the operational readiness of components including, but not limited to, the HPCI pump and subsystem components, per Dresden Station Technical Specifications and Inservice Testing Program, an activity affecting quality.

Procedure DOS 230003, step I.7.y states, if this surveillance has been run as a post-maintenance test after HPCI system maintenance where the system was partially OR fully drained, THEN perform a fill and vent of the discharge piping downstream of the MO 22301-9, PP DISCH VLV, per DOP 230001.

Contrary to the above, on November 16, 2023, the licensee failed to accomplish step I.7.y in accordance with procedure DOS 230003. Specifically, the licensee staff was not aware the fill and vent step was required for the circumstances and incorrectly marked the step as N/A.

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

Fire Barrier Impaired Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.12] - Avoid 71152A NCV 05000237,05000249/202400202 Complacency Open/Closed The inspectors identified a finding of very low safety significance (Green) and an associated non-cited violation (NCV) of Technical Specifications 5.4.1.c, Fire Protection Program Implementation, for the licensees failure to implement procedures associated with fire barriers. Specifically, the licensee failed to implement step G.4.C of procedure DFPP 417501, Fire Barrier Integrity and Maintenance, Revision 25, and prevented a fire door from automatically closing as required and rendering the barrier non-functional when a roll of duct tape was used to prop the door open during maintenance on a fire detection system.

Description:

On April 10, 2024, the licensee was performing fire detector testing in the Unit 2 emergency diesel generator (EDG) room in accordance with procedure DFPS 418303, Diesel Generator Room and Alterex Cabinet Heat Detector Test, Revision 12. During normal plant tour the inspectors walked past the Unit 2 EDG room and noted that the technician associated with the test had propped open the Unit 2 EDG room fire door with a roll of duct tape. The roll of duct tape prevented the fire barrier from being able to automatically close and latch. The inspectors questioned the electrical maintenance technician about the practice and was told they had stepped out of the Unit 2 EDG room because it was hot in the room and that propping the door open was normal practice. In order to test heat detectors in the Unit 2 EDG room the licensee had isolated the gaseous suppression system to prevent inadvertent actuation and instituted an hourly fire watch in accordance with the Technical Requirements Manual and procedural requirements.

Operations was unaware the Unit 2 EDG fire door had been propped open during the maintenance and had not authorized a plant barrier impairment permit in accordance with procedure CC-AA201 Plant Barrier Control Program, Revision 14. Technical Requirements Manual 3.7.n requires, in part, to verify the OPERABILITY of the Gaseous Suppression System immediately or to enter TLCO 3.0.g immediately and implement evaluated alternate measures associated with the impairment of fire barrier. The inspectors reviewed procedure DFPP 417501, Fire Barrier Integrity and Maintenance, Revision 25 and concluded the licensee failed to implement step G.4.c which stated, Swinging entry fire doors must be kept closed, unless they are fastened open with a fusible link which is designed to automatically close the door during a fire. For example, the shutdown cooling pump room fire doors have magnetic holders that allow the doors to remain open during normal operation. It is important that nothing be placed in front of the doors which could prevent them from automatically swinging closed. The Unit 2 EDG room fire door does not have a fusible link to automatically close the door during a fire.

Corrective Actions: Operations verified the duct tape had been removed and the fire door function restored.

Corrective Action References: CR 4765553 NRC Observation Follow Up

Performance Assessment:

Performance Deficiency: The licensee failed to properly implement step G.4.c of procedure DFPP 417501, Fire Barrier Integrity and Maintenance, Revision 25, which stated Swinging entry fire doors must be kept closed, unless they are fastened open with a fusible link which is designed to automatically close the door during a fire. For example, the shutdown cooling pump room fire doors have magnetic holders that allow the doors to remain open during normal operation. It is important that nothing be placed in front of the doors which could prevent them from automatically swinging closed.

Specifically, licensee electricians propped open the Unit 2 EDG room door with duct tape during fire detector testing that would have prevented the door from automatically swinging closed during a fire.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the inability for the Unit 2 EDG fire door to close and latch could have affected the ability of the EDG to perform its safety-related function during a turbine building fire.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The inspectors used IMC 0609 Attachment 4, Initial Characterization of Findings, issued December 20, 2019, and determined, in accordance with Table 3, that the finding screened into IMC 0609 Appendix F, Fire Protection Significance Determination Process, issued May 2, 2018. The inspectors reviewed Table 1.2.1 of IMC 0609 Appendix F and assigned a finding category of Fire Confinement since the impacted barrier was a fire door. The inspectors reviewed IMC 0609 Appendix F Attachment 2, Degradation Rating Guidance, issued May 2, 2018, and determined that the Unit 2 EDG room door being propped open was a High Degradation finding. The inspectors reviewed the Fire Confinement questions contained in IMC 0609 Appendix F and answered no to question 1.4.4A, no to question 1.4.4B, yes to question 1.4.4C and no to question 1.4.4D and screened the finding to Green.

Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, the individuals performing fire detector testing failed to verify plant barrier impairment requirements were implemented in accordance with CC-AA201 prior to propping the Unit 2 EDG fire door open and assumed the periodic fire watch controls implemented associated with the gaseous fire suppression system were sufficient for impairing the fire barrier.

Enforcement:

Violation: Technical Specification 5.4.1.c, Procedures, requires, in part, that written procedures covering fire protection program implementation, be established, implemented and maintained. Procedure DFFP 417501, Fire Barrier Integrity and Maintenance, Revision 25, was the established procedure to ensure fire barriers were kept in proper condition at all times. Specifically, procedure DFPP 417501 step G.4.c states, in part, that swinging entry fire doors must be kept closed, unless they are fastened open with a fusible link which is designed to automatically close the door during a fire.

Contrary to the above, on April 10, 2024, the licensee failed to implement written procedures covering fire protection program implementation. Specifically, the licensee prevented the Unit 2 EDG room fire door from being able to close and latch as required by propping open the door with a roll of duct tape.

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

2/3 Emergency Diesel Generator Output Breaker Opened During Surveillance Testing Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [P.2] - 71152A Systems NCV 05000237,05000249/202400203 Evaluation Open/Closed A finding of very low safety significance (Green) was self-revealed for the licensees failure to identify a condition adverse to quality. Specifically, upon discovering in 2020 that procedure DIP 210028, Banana Jack Adapter Installation, had deficient instructions for securing the banana jacks, the licensee failed to identify whether any safety-related/risk-significant components still had banana jacks installed without design verified torque. As a result, the licensee failed to identify that the banana jacks, and therefore the control circuitry wiring on the 2/3 emergency diesel generator (EDG), were loose until the EDG failed during surveillance testing on January 30, 2023.

Description:

At 12:55 a.m. on January 30, 2023, the 2/3 EDG was declared inoperable to perform monthly operability surveillance testing. The licensee performed a low idle local start of the EDG, closed in 2/3 diesel output breaker to bus 331 and achieved full load at 1:46 a.m.

At 3:06 a.m. the 2/3 EDG breaker to bus 331 tripped open unexpectedly. The EDG responded as expected and achieved idle conditions. At 3:10 a.m., the 2/3 EDG was placed in a secured status, declared inoperable and unavailable, and troubleshooting efforts commenced.

During troubleshooting the licensee discovered a loose banana jack in the 2/3 EDG local control panel which is mounted to the side of the 2/3 EDG at TB25C. The licensee was able to tighten the banana jack five turns. The loose banana jack resulted in control circuitry wiring being loose and caused the open circuit conditions observed during unloaded diesel run troubleshooting. Once the banana jack was tightened and the control wiring properly secured, the 2/3 EDG successfully passed the monthly operability surveillance test and was restored to an operable and available status at 4:22 p.m. on February 1, 2023.

The inspectors determined that due to the improper torque settings, the banana jack at TB25C had become lose over time from vibrations during diesel operation. This, in turn, caused the underlying wiring to become unsecured, resulting in a loss of continuity and causing voltage fluctuations. The fluctuating voltage affected the excitation circuitry and could cause a loss of excitation voltage, preventing the diesel generator from functioning. During the January 30 testing, these voltage fluctuations caused the output breaker to open as a protective measure. During emergency operation, such as a loss of offsite power event, this breaker protective feature is blocked, and the breaker will remain closed; however, the voltage fluctuations could still result in a loss of excitation, and therefore the diesel could not be counted on to reliably function.

During normal operation, relay VSR would pick up, seal in, and energize relays ER and EXC.

The EXC relay contacts ensure proper operation of the excitation circuitry. The voltage fluctuations could result in a loss of voltage to all three relays and, due to the open EXC relay, the loss of the excitor reflashing current. The loss of the reflashing current energized relay RT-DG 2/3 and the associated contact caused the output breaker to trip. During an emergency start, such as from a loss of offsite power, the RT-DG 2/3 relay is blocked, and the breaker would remain closed. However, the VSR, ER, and EXC relays would function as normal, and a loss of excitation could occur preventing the EDG from functioning.

Inspector review identified that the banana jack had been installed on March 26, 2019, under Work Order 466527806, 2/3 10 Year EDG Time Delay Relay (TDR3) Replacement, in accordance with procedure DIP 210028, Banana Jack Adapter Installation, Revision 15.

Procedure DIP 210028 specified the banana jack installed at terminal block TB25C terminal point 12 torqued snug tight.

The inspectors reviewed condition report 4360154, Procedure Revisions Required - Corporate Torque HIT Actions, and determined that the licensee had changed torque requirements for the installation of banana jacks from a required torque value to snug tight when procedure DIP 210028, Banana Jack Adapter Installation, Revision 12 was issued on March 23, 2012. The inspectors reviewed condition reports 957053 Banana Jack Defective, Did Not Install for Pre Outage, 1094898 Banana Jacks Adapters are Defective, Cannot Torque, 1104972 Cannot Achieve Torque Value of Banana Jack, and 1110756 Torque Specs in Procedure Are Not Correct, generated between August 24, 2009, and September 8, 2010, which documented material deficiency issues noted during banana jack installation while attempting to torque the banana jacks to the procedurally required value. Specifically, the licensee encountered an issue where the plastic hex nut bonded to the banana jack metal part would strip and spin freely during torquing evolutions.

Inspector review determined that Calculation CMED048403, Evaluation of Pomona Banana Jack Adapters for Terminal Blocks Identified in CECo EM Standards, Revision 0, had been established as the design calculation of record associated with banana jacks. CMED048403 calculated and documented required thread engagement to ensure the banana jack did not impact system function when installed. On July 31, 2020, the licensee documented in condition report 4360154 that procedure use of torque snug tight was no longer acceptable direction for tightening components and specifically identified that procedure DIP 210028 required revision. The licensee determined a torque value for terminal screws and included torque values in revision 16 of procedure DIP 210028 on June 3, 2021. The inspectors identified a design control question associated with the use of snug tight with respect to banana jack installation and verification that function would have been maintained.

The inspectors determined that the failure to identify that the banana jacks installed on the 2/3 EDG were not properly torqued was a condition adverse to quality. Procedure PI-AA120, Issue Identification and Screening Process, Revision 10, Section 3.7 delineates the responsibilities of issue originators, which includes ensuring conditions that have or could have an undesirable effect on performance of equipment are properly documented. The procedure defines a condition adverse to quality as any failures, malfunctions, deficiencies, defective items, or nonconformance.

Specifically, the licensee did not perform a review of plant equipment which had banana jacks installed in accordance with the no longer acceptable instructions to determine if these jacks still securely held the underlying wiring. Additionally, the inspectors determined that the failure to identify the condition adverse to quality and subsequent evaluation of actual plant conditions resulted in a missed opportunity to evaluate and verify the adequacy of snug tight and thread engagement to ensure function was maintained. As a result, they failed to identify that the banana jacks installed on the 2/3 EDG had loosened over time from diesel operation, causing the underlying wires to become unsecured. The unsecured wires resulted in a loss of continuity causing voltage fluctuations which could affect the operability of the diesel. This operability concern was a condition adverse to quality as defined by procedure PI-AA120.

Because the 2/3 EDG is of similar design to the Unit 2 and 3 EDGs and blackout diesels, the inspectors questioned the licensee regarding the extent of condition. The licensee performed torque checks on the banana jacks installed on the Unit 2 and 3 diesels, station blackout diesels and determined that they were secure and met the current requirement of procedure DIP 210028.

Corrective Actions: Corrective actions included, but were not limited to, securing the excitation circuitry wires by installing the banana jack at TB25C to required torque in accordance with procedural requirements and reperforming an operability run of the 2/3 EDG, and performing an extent of condition review for similar conditions on the other two EDGs as well as the station blackout diesels.

Corrective Action References: CR 4551179 2/3 EDG Output Breaker Trip, CR 4687009 NRC Question: 2/3 EDG Banana Jacks, CR 4691063 U2 Extent of Condition Review from IR 4551179, CR 4691067 U3 Extent of Condition Review from IR 4551179, CR 4692803 U2 SBO Banana Jack Extent of Condition Walkdown, and CR 4692804 U3 SBO Banana Jack Extent of Condition Walkdown

Performance Assessment:

Performance Deficiency: The inspectors determined that the failure to identify a condition adverse to quality on the Unit 2/3 EDG, was a performance deficiency. Specifically, upon discovering that procedure 210028, Banana Jack Adapter Installation, had deficient instructions for securing the banana jacks, the licensee failed to perform an extent of condition review to determine whether any safety-related/risk-significant components still had banana jacks installed with inappropriate torque. As a result, the licensee failed to identify that the banana jacks, and therefore the control circuitry wiring on the 2/3 EDG, were loose, potentially affecting its operability until it subsequently failed during surveillance testing.

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 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 failed to identify that banana jacks were installed on the 2/3 diesel to deficient specifications until the diesel subsequently failed during surveillance testing.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power. The inspectors screened the finding using Exhibit 2 and answered Yes to question A.3 that the degraded condition represents a loss of the probabilistic risk assessment (PRA) function of one train of a multi-train TS system for greater than its TS allowed outage time and screened into a Detailed Risk Evaluation.

A Region III senior reactor analyst (SRA) performed a detailed risk evaluation to assess the significance of the finding. The finding was assumed to result in the 2/3 EDG breaker to bus 331 tripping open resulting in a failure to run of the EDG. The exposure period was calculated to be 152 days based on the 24-hour mission time and successful operation of the EDG during that period. The SRA used a recently modified Standardized Plant Analysis Risk (SPAR) model to analyze the finding. The model modification was necessary to properly credit post-Fukushima diverse and flexible coping (i.e., FLEX) strategies and incorporate FLEX equipment reliability consistent with the information in PWROG18042NP, Revision 1, FLEX Equipment Data Collection and Analysis, (ADAMS ML22123A259), which is considered best available information. All three EDGs and the two station blackout diesel generators were included in the common cause grouping because the performance deficiency had the potential to impact all five. The SRA reviewed and incorporated the licensees fire risk results since the Dresden SPAR model does not evaluate fire risk. The change in core damage frequency (CDF) due to internal events, seismic, tornadoes, high winds, and fire was estimated to be less than 1E6/year. The dominant core damage sequence for internal events involved a weather-related loss of offsite power with a common cause failure to run of all diesels, and a failure to recover power in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The change in large early release frequency (LERF) was also considered and estimated to be below 1E7/year. Thus, the inspectors determined the finding was of very low safety significance (Green).

Cross-Cutting Aspect: P.2 - Evaluation: The organization thoroughly evaluates issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Specifically, the licensee failed to perform an evaluation to address extent of condition for banana jacks installed on plant equipment to inadequate work instructions that ultimately resulted in the failure and unavailability of the 2/3 EDG.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures be established to ensure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified.

10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, that the licensee provide for verifying or checking the adequacy of design, such as by the performance of design reviews, by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.

Contrary to the above, from July 31, 2020, to January 30, 2023, the licensee failed to identify a condition adverse to quality. Specifically, the licensee failed to identify that the banana jacks installed on the 2/3 EDG had loosened over time from diesel operation, causing the underlying wires to become unsecured. The unsecured wires resulted in a loss of continuity causing voltage fluctuations affecting the operability of the diesel.

Additionally, as of June 30, 2024, the licensee failed to verify the adequacy of design by not verifying the adequacy of established thread engagement and snug tight values established in CMED048403 were sufficient to ensure the continuity of underlying wires were maintained and that function retained.

The disposition of this finding and associated violation closes URI:

05000237,05000249/202300401.

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

The disposition of this finding and associated violation closes URI:

05000237,05000249/2023004-01.

Failure to Properly Implement Fire Impairment Procedure Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.12] - Avoid 71152S NCV 05000237,05000249/202400204 Complacency Open/Closed The inspectors identified a finding of very low safety significance (Green) and associated non-cited violation (NCV) of Technical Specification 5.4.1c, when the licensee failed to follow a step in procedure OP-AA201007, Fire Protection Impairment Control. Specifically, during a period when a continuous fire watch was required to compensate for an inoperable detection and suppression system, the licensee failed to ensure the fire watch would implement step 3.5.4 of procedure OP-AA201007, Fire Protection Impairment Control, in its entirety. The licensee failed to ensure the continuous fire watch would attempt to extinguish the fire in accordance with step 3.5.4.

Description:

On July 18, August 2, August 16, August 29, September 7, and December 5, 2023, the licensee removed the XL3 fire detection system from service and various deluge systems were isolated to prevent inadvertent actuation. In addition, the site entered Technical Requirements Manual (TRM) 3.3.e for all inoperable fire detection instrumentation, TRM 3.7.j for inoperable water suppression systems, and TRM 3.7.k for inoperable gaseous suppression systems. The TRM required actions included, but were not limited to, establishing a continuous fire watch with backup fire suppression equipment. The site established fire watches for the impacted areas which included continuous fire watches for the auxiliary electric equipment room (AEER), 2/3 mezzanine 534' elevation, and both Unit 2 (U2) and Unit 3 (U3) hydrogen seal oil areas. In addition, roving fire watches were established for the U2 turbine building, U2 reactor building, U3 turbine building, U3 reactor building, U2 turbine building clean side, Unit 1 (U1) auxiliary bays, 2/3 crib house, U1 crib house, and U2 and U3 transformer areas.

On December 5, 2023, during the established fire watches, inspectors questioned two of the four continuous fire watches about their responsibilities. The continuous fire watch standers responded they were briefed to call the relevant site phone extension in the event of a fire.

The inspectors questioned if they would attempt to extinguish the fire and the fire watches indicated they were not briefed to do so. The inspectors brought this observation and additional questions to the site, and the site generated action report (AR) 4721719 to capture the question. In this AR, the site stated the current practice was to have the fire watch call the extension, and operations would immediately dispatch to the area with appropriate backup equipment for firefighting, as needed.

The inspectors questioned the site on the availability of not only the automatic Halon fire suppression system, but also the manual actuation Cardox system in the AEER. The site responded that the Halon system was isolated per Work Order 505998022, but they could dispatch personnel to restore the system to support manual actuation. In addition, the inspectors questioned the licensee if they had documented evaluations of any alternate compensatory measures, as allowed by TRM 3.0.g, and the licensee informed the inspectors they had not.

Corrective Actions: The licensee entered the issue into their corrective action program and created action items to brief expectations for validation of fire watch responsibilities.

Corrective Action References: 4721719, IEMA question wording in TRM 3.7.j vs Fire Impairment

Performance Assessment:

Performance Deficiency: The licensee failed to properly implement step 3.5.4 of procedure OP-AA201007, Fire Protection Impairment Control, which states, Immediately REPORT the discovery of smoke or fire to the control room emergency number, and then ATTEMPT to EXTINGUISH the fire only if it is obviously within the capacity of the fire protection equipment available. Specifically, the current practice was to only have fire watches notify the control room of discovery of smoke or a fire. This is contrary to the guidance and requirements established in the procedures requiring fire watches to notify and attempt to extinguish and is a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the continuous fire watch was a compensatory measure for the fixed fire suppression system being removed from service for maintenance and was being relied upon to perform an early fire suppression function. The failure to properly implement the procedure adversely affected the early suppression function, which was no longer available.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The inspectors assessed the significance of the finding using Inspection Manual Chapter (IMC) 0609, Appendix F, Fire Protection Significance Determination Process. Using IMC 0609, Appendix F, Attachment 1, Fire Protection Significance Determination Process Worksheet, the inspectors determined that this issue was associated with fixed fire protection systems and low degradation rating could not be assigned in accordance with Step 1.3.1A as early fire suppression by the fire watch was not available. The inspectors determined, in accordance with step 1.4.2A, the deficiency regarding the continuous fire watch adversely affected the ability of the systems to protect equipment important to safe shutdown due to unavailability of early fire suppression.

In accordance with Step 1.5, the Region III senior reactor analyst (SRA) noted that the licensee had a fire probabilistic risk assessment (PRA) model capable of evaluating the risk significance of this finding. The results of this model were used by the licensee to provide an evaluation of the finding. This evaluation made the following key assumptions:

(1) The exposure time for the finding was 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />.

(2) The finding resulted in no credit for automatic fire suppression or early fire detection in areas where these systems are credited in the fire PRA.

(3) Catastrophic or complex fire scenarios were beyond the capability of the fire watch and were not adjusted for the finding.

(4) The finding did not impact manual firefighting associated with the fire brigade. To determine the significance of the finding, the non-suppression probability was adjusted to represent the impact of the finding and applied to the baseline fire model PRA cut sets.

The SRA reviewed the evaluation and determined that the licensee had used the model with appropriate assumptions and methods to determine a bounding risk review for the issue. For Unit 2, the conditional increase in CDF was calculated to be 1.6E7/yr and the LERF increase was calculated to be 3.0E8/yr, very low safety significance (Green). For Unit 3, the conditional increase in CDF was calculated to be 6.4E8/yr and the LERF increase was calculated to be 1.8E8/yr, very low safety significance (Green). The SRA noted the largest contributor to the increase in conditional risk for this finding was associated with electrical panel fire scenarios in the AEER. The dominant core damage sequence was associated with spurious activation of the automatic depressurization system and an associated unavailability of low-pressure injection systems leading to core damage. The SRA referenced IMC 0609, Appendix F, Attachment 1, and determined that the licensees basis for the risk review was acceptable and therefore concurred with the risk determination of very low safety significance.

Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, the licensee built a mental model of just having the fire brigade responding to potential fires and did not consider the importance of early fire suppression performed by the fire watch.

Enforcement:

Violation: Technical Specification 5.4.1.c, Fire Protection Program Implementation, requires, in part, that written procedures covering fire protection program implementation, be established, implemented, and maintained. The licensee established procedure OP-AA201007, Revision 2, Fire Protection Impairment Control to address the administrative process for the tracking, reporting, and restoring fire protection impairments as well as provide instruction for establishing and performing compensatory measure fire watch inspections in accordance with the fire protection program. Procedure OP-AA201007, Rev. 2, Step 3.5.4 requires immediately REPORT the discovery of smoke or fire to the control room emergency number, and then ATTEMPT to EXTINGUISH the fire only if it is obviously within the capacity of the fire protection equipment available.

Contrary to the above, on July 18, August 2, August 16, August 29, September 7, and December 5, 2023, the licensee failed to implement procedures covering fire protection program implementation. Specifically, Step 3.5.4 of procedure OP-AA201007 was not implemented when the licensee established continuous fire watches with the direction to only report to the control room any discovery of smoke or fire and they were not expected or informed they should attempt to extinguish as well.

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 71152S 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: Technical Specification (TS) 5.4.1.c requires that written procedures be established, implemented, and maintained for activities associated with the implementation of the sites fire protection program. One of several procedures established by the licensee to meet this requirement was OP-AA201007, Fire Protection System Impairment Control.

Revision 2 of this procedure, which was the revision active and in effect on May 22, 2024, required that an hourly fire watch be established and maintained for Fire Zone 11.3 associated with the 2/3 cribhouse while XL3 fire detection device 5122 was not operable.

Contrary to this requirement, on May 22, 2024, the licensee failed to implement the compensatory hourly fire watch as required by TS 5.4.1.c and OP-AA201007, Revision 2.

Specifically, a communications error between on-shift operations crew members resulted in the inadvertent securing of the hourly fire watch for Fire Zone 11.3 for approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> while fire detection associated with that fire zone was not operable.

Significance/Severity: Green. The inspectors assessed the significance of the finding using Inspection Manual Chapter (IMC) 0609, Appendix F, Attachment 1, Fire Protection Significance Determination Process, dated May 2, 2018, and answered yes to Step 1.3 since the failed detector represented less than 10 percent of smoke or heat detectors degraded (non-functional, misplaced or missing), and functional detection was available near combustibles of concern (Green).

Corrective Action References: CR 4775724, 3.3.e Required Actions Not Met

Observation: Adverse Trend in Implementation of Fire Protection Program 71152S The inspectors performed a semiannual review of issues entered into the corrective action program and a cognitive review of plant observations over the period of January 1, 2024, to June 30, 2024, to identify any potential trends that might indicate the existence of a more significant safety issue. The NRC inspectors identified several examples of issues with implementation of the fire protection program. Due to the observed potential adverse trend in the first half of 2024, the inspectors expanded their review to encompass the last quarter of 2023, where more examples were identified.

The first example occurred on December 5, 2023, when inspectors questioned fire watches staged in the field about their responsibilities. The questions and issues were documented in an action report (AR). The inspectors had discussions with operations and the fire marshal in March 2024 to better understand the issue, the sites expectations, and the sites current practice of implementing compensatory measures. As a result of the inspectors discussions and review in regard to a potential adverse trend in implementation of the fire protection program, a Green, non-cited violation of the sites failure to implement the compensatory measures procedure OP-AA201007, Fire Protection System Impairment Control, was identified, dispositioned, and documented in this inspection report, 2024002.

A second example occurred on April 10, 2024, when during the sites performance of fire detector testing in the Unit 2 EDG room, inspectors performing routine plant walkdowns found the credited fire barrier, the fire door, propped open. As a result of the inspectors observation and evaluation, a Green, non-cited violation of the licensees failure to implement the fire barrier procedure was identified, dispositioned, and documented in this inspection report 2024002.

A third example occurred on May 21, 2024, when the site inadvertently secured an hourly fire watch. The licensee identified an hourly fire watch in the 2/3 cribhouse was secured even though the XL3 device 5122 remained in alarm and TRM 3.3.e remained active. TRM 3.3.e, Fire Detection Instrumentation, requires the licensee to establish a fire watch patrol, perform fire watch inspections hourly, and either restore the fire detection instrumentation to operable within 14 days or prepare a corrective action program report. The site identified the improperly secured fire watch and reestablished an hourly fire watch within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, as allowed by TRM 3.0.c.

Along with the examples above, on April 24, 2024, a visible flame and sparking were observed by the inspectors during Unit 3 battery charger 4-hour load test. When the inspector reached out to the control room, the shift manager had not been informed by the workers in the field about this event and thus, no evaluation for entry into DOA 001010, Fire/Explosion, occurred until informed by the NRC inspectors.

In addition, the inspectors noted multiple ARs generated during Unit 2s refueling outage at the end of 2023 regarding improperly stored transient combustibles. Specifically, inspectors identified on back-to-back days that transient combustibles were stored in the reactor building under a staircase that was clearly marked with a sign to not store any transient combustibles in that area. Both times the inspectors brought these observations to the site, who documented the issue in ARs and removed the items. The inspectors concluded there were numerous opportunities for the site to identify and document these improperly stored transient combustibles as they were in a frequently traveled area prior to the inspectors identifying the issue.

Overall, the inspectors identified multiple instances of a declining trend in proper implementation of the sites fire protection program. The site has implemented fire protection blitzes with different focus areas each week to improve overall site knowledge, awareness, and sensitivity to the different areas that fall under the fire protection program. The inspectors did identify violations associated with these activities, as noted above.

EXIT MEETINGS AND DEBRIEFS

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

• On July 24, 2024, the inspectors presented the integrated inspection results to H. Patel, Plant General Manager, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action 4740131 Summer Readiness Concern: 3A Circ Water Pump Bearing 02/01/2024

Documents Temps

4775294 Summer Readiness: U2 PDC HVAC Controller has Refrig 05/20/2024

Alarm 1

Corrective Action 4767032 NRC ID: Missile Hazards/Housekeeping 04/17/2024

Documents

Resulting from

Inspection

Miscellaneous Certification of 2024 Summer Readiness 05/15/2024

Procedures DOA 001002 Tornado Warning/Severe Winds 28

DOA 575001 Ventilation System Failure 73

DOP 575009 Auxiliary Electrical Equipment Room Air Conditioning Unit 34

DOP 575022 Line Up the Aux Electrical Equipment Room Through East 22

Turbine Building HVAC

OP-AA108111-Severe Weather and Natural Disaster Guidelines 28

1001

OP-DR108111-Hot Weather Strategy 7

1001

WC-AA107 Seasonal Readiness 29

71111.04 Corrective Action 4768498 NRC ID: DOP 6600M2 Requires Revision 04/22/2024

Documents

Resulting from

Inspection

Drawings M27 Diagram of Core Spray Piping AAO

M478 Sheet 2 Diagram of Diesel Generator Lube Oil Piping K

M49 Diagram of Standby Gas Treatment RB

M517 Sheet 2 Diesel Generator Engine Cooling Water System J

M518 Sheet 2 Diesel Generator Fuel Oil System G

Procedures DOP 1400E1 Unit 2 Core Spray System Electrical Checklist 4

DOP 1400M1 Unit 2 Core Spray System 24

DOP 1400M1/E1 Unit 3 Core Spray System 21

Inspection Type Designation Description or Title Revision or

Procedure Date

DOP 2300M1/E1 Unit 3 HPCI System Checklist 41

DOP 6600E2 Unit 2/3 Standby Diesel Generator 6

DOP 6600M2 Unit 2/3 Emergency Diesel Generator Checklist 29

DOP 750001 Standby Gas Treatment System Operation 40

DOP 7500M1/E1 Unit 2/3 Standby Gas Treatment 6

M374 Diagram of High Pressure Coolant Injection Piping CZ

71111.05 Corrective Action 4773588 24199-157 Oil Storage Room Sprinkler Valve Leak 05/12/2024

Documents

Corrective Action 4767535 NRC Identified Issues in The Plant 04/18/2024

Documents 4774445 NRC Questions: U2 Turbine Building 05/15/2024

Resulting from

Inspection

Fire Plans 104 U2RB4 Unit 2 HPCI Pump Room Elevation 476' 6

118 U3RB21 Unit 3 Southeast Corner Room Elevation 476' 3

20 U3RB23 Unit 3 Reactor Building Ground Floor Elevation 517' 5

136 U2TB39 Unit 2 Oil Lube Room Elevation 517' 3

139 U2TB42 Unit 2 Reactor Feed Pumps Elevation 517' 2

141 U2TB44 Unit 2 Condensate Transfer Pumps/Hallway Elevation 517' 2

2 U2TB45 Unit 2 Track Way Area Elevation 517' 4

144 U2TB47 Unit 2 Switchgear and Motor Control Center Elevation 517' 4

161 U3TB72 Unit 3 Reactor Feed Pumps Elevation 517' 3

163 U3TB74 Unit 3 Condensate Transfer Pumps/Hallway Elevation 517' 5

164 U3TB75 Unit 3 Track Way Area Elevation 517' 8

165 U3Tb-76 Unit 3 Switchgear Area Elevation 517' 6

175 U2/3TB92 Unit 2/3 Electro-Hydraulic Control Reservoir Area 4

Elevation 517'

176 U2/3TB93 Unit 2/3 Condensate Demineralizer Area Elevation 517' 2

184 2/3 EDG Unit 2/3 Swing Diesel Generator Room Elevation 517' 7

196 Circ PPs-124 Unit 2/3 Circulating Water Pumps Elevation 490' 2

197 SW PPs-125 Unit 2/3 Service Water Pumps / Traveling Screens 3

Elevation 509'

198 U2/3 CH126 Unit 2/3 Crib House Ground Elevation 517' 3

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.06 Corrective Action 4721223 Unexpected Trip of 393 Cubicle B3 During 3B Reactor 12/03/2023

Documents Building Floor Drain Sump Level Switch Testing

4775243 Unexpected Alarm: 903D-19, LPCI/CS West Sump Level HI 05/20/2024

Miscellaneous DR-PSA012 Dresden Nuclear Power Station PRA Internal Flood 5

Evaluation Summary and Notebook

Procedures DOA 004002 Localized Flooding in Plant 29

Work Orders 1644902 Unit 3 West LPCI Room Watertight Door Seal Inspection 06/19/2019

1686415 Unit 2 East LPCI Room Watertight Door Seal Inspection 01/29/2020

28946 Unit 3 East LPCI Room Watertight Door Seal Inspection 06/04/2020

1732537 Unit 2 West LPCI Room Watertight Door Seal Inspection 01/21/2021

1917819 Unit 3 West LPCI Corner Room Level Switch Functional Test 07/21/2022

4674297 Unit 3 East LPCI Corner Room Level Switch Functional Test 07/23/2020

4778622 Unit 3 East LPCI Room Watertight Door Clean/Lube 06/01/2021

4806348 Unit 2 West LPCI Room Watertight Door Clean/Lube 01/11/2021

4808698 Unit 2 West LPCI Corner Room Level Switch Functional Test 08/09/2021

25259 Unit 3 Reactor Building Floor Drain Sump B Level Switch 12/03/2023

Functional Test

4934771 Unit 3 Reactor Building Floor Drain Sump A Level Switch 12/04/2023

Functional Test

4935274 Unit 3 West LPCI Room Watertight Door Clean/Lube 06/20/2022

4945610 Unit 2 Reactor Building Floor Drain Sump B Level Switch 09/15/2023

Functional Test

4945611 Unit 2 Reactor Building Floor Drain Sump A Level Switch 09/15/2023

Functional Test

5005525 Unit 2 East LPCI Room Watertight Door Clean/Lube 01/25/2023

5008533 Unit 2 East LPCI Corner Room Level Switch Functional Test 09/18/2023

283541 Unit 2 Reactor Building Floor Drain Sump Pit A Inspection09/15/2023

283542 Unit 2 Reactor Building Floor Drain Sump Pit B Inspection09/15/2023

24062 Unit 3 Reactor Building Floor Drain Sump Pit A Inspection12/04/2023

24063 Unit 3 Reactor Building Floor Drain Sump Pit Inspection B12/03/2023

71111.11A Procedures TQ-AA150F25 LORT Annual Exam Status Report 007

71111.11Q Miscellaneous Dresden Unit 2 - D2 Rod Recovery Load Drop 1 04/03/2024

NF-AB720F-5 Special Maneuver Rod Move Sheet - D229010 04/03/2024

Inspection Type Designation Description or Title Revision or

Procedure Date

OP-AB3001003 ReMA Plan D229010 D2C29 Rod Recovery Load Drop 1 04/04/2024

71111.12 Corrective Action 4689928 U3 SBO Would Not Synchronize to Bus 33 07/11/2023

Documents 4723005 2B Core Spray Pmp Fail to Start 12/12/2023

23733 3A SDC Pp Failed to Bump Check During Monthly Checks 12/15/2023

27126 4KV Circuit Breaker Trend IR for Last 6 Months of 2023 01/08/2024

4750415 U3 LPRM Drift 2409D 02/15/2024

4758416 4kv Breaker Failed Closed Coil Continuity Checks 03/16/2024

4761211 4KV Breaker UTC 0001281396 Failed to Charge 03/26/2024

4761834 4kV Breaker UTC 0001281396 Charging Motor Opened 03/28/2024

4771800 3A SDC Pump Breaker Closing Coil Continuity High 05/03/2024

4772706 MOC Switch Sticking Bus 331 Cub 11 05/08/2024

4772909 LPRM 30756-4849B Bypassed 05/08/2024

4773254 Bus 331, Cub 11 MOC Switch Cam Follower Requires 05/10/2024

Part Update

4775905 Bypassed U3 LPRM 2409C 05/23/2024

4776426 LPRM Drift U2 3249A 05/25/2024

Miscellaneous Incore Monitoring System Health Report 06/12/2024

GEH2038E Vendor Manual: Control and Transfer Switch Type SBM 0

GEI88762A GE Magne-Blast Circuit Breaker Vendor Manual 0

Procedures DES 670009 Inspection and Maintenance of General Electric MC4.76 30

Horizontal Draw-Out Metal-Clad Switchgear

DIP 070006 LPRM Receipt Acceptance Testing 14

DOP 070008 Guideline to Correct an Abnormal LPRM 21

DOP 070009 APRM System Gain Adjustments 5

MA-AB725114 Preventative Maintenance on Merlin Gerin G26 Type SF6 13

4kV Circuit Breakers

Work Orders 482342602 EWP EM Receipt Inspection 4kV Breaker UTC 1185078 04/20/2022

98071826 16Y PM Overhaul 4KV Bkr UTC 0000874035 06/10/2013

71111.13 Corrective Action 4779707 Unit 2 EDG Lower Air Start Pinion Did Not Fully Disengage06/10/2024

Documents 4780156 High Resistance Suspected from Relay 30590-0105D 06/12/2024

Corrective Action 4764621 NRC Identified: Protected Pathway Posting Disturbed 04/09/2024

Documents 4774815 Protected Pathway Postings for 2B LPCI HX 05/16/2024

Inspection Type Designation Description or Title Revision or

Procedure Date

Resulting from

Inspection

Miscellaneous Work Week Highlights 4/8/24 - 4/14/24 04/08/2024

Work Week Highlights 5/6/24 - 5/12/24 05/09/2024

Work Week Highlights 5/13/24 - 5/19/24 05/14/2024

Work Week Highlights 5/20/24 - 5/26/24 05/21/2024

WR 01566001 IR 04780156: High Resistance Suspected from 06/12/2024

Relay 30590-0105D

Procedures DIS 050002 Reactor Vessel Low Water Level Scram and Low Low Water 58

Level Isolation MTU/STU Channel Calibration and

Functional Test

OP-AA102104 Attachment 2: Unit 2/3 Standing Order 5

OP-AA108117 Protected Equipment Program 7

OP-DR108117-Protected Equipment and Pathway Policy 6

1001

OP-DR201012-Dresden On-Line Fire Risk Management 8

1001

WC-AA1011006 On-Line Risk Management and Assessment 4

Work Orders 191581203 OP Swap 4kv Brk Bus 331, Cub 11 05/08/2024

(3A Core Spray Pump) + PMT

2459801 EM D3 8Y PM 4kv Cub Insp Bus 331 Cub 11; 05/08/2024

3A Core Spray Pmp

2459802 EM Pre-OOS Space Htr Check Bus 331 Cub 11; 04/30/2024

3A CS Pmp

194807701 EM T/S&R 367331-11 Secondary Chipped 05/07/2024

5440178 FIN Replace 2B ASD OLM A1 05/24/2024

71111.15 Corrective Action 4757787 Bypassed LPRM Trend 03/13/2024

Documents 4770320 Main Feed Breaker from UAT 21 to Bus 22 Spring Indication04/29/2024

4771001 Buzzing Sound Heard from U2 125 VDC Alt Charger 05/01/2024

4775905 Bypassed U3 LPRM 2409C 05/21/2024

Procedures DOP 070008 Guideline to Correct an Abnormal LPRM 21

OP-AA108112 Plant Status and Configuration 13

Work Orders 5346018 EWP EM D2 12M Com/TS 125 VDC SBO Batt 28330-6A 0

Inspection Type Designation Description or Title Revision or

Procedure Date

Surv

99063463 EM EWP Rec Insp on 4KV Bkr UTC 0000874156 05/27/2016

71111.24 Calculations NED-I-EIC0113 Isolation Condenser Steam/Condensate Line High Flow 004

Setpoint Error Analysis

Corrective Action 01130468 Verification of Removal of All Test Equipment 10/25/2010

Documents 4761270 2/3 EDG Failed to Start Via U2 Auto Start Relay 03/26/2024

4769870 U3 EDG Cylinder 19 Exhaust Temperature Indication Broke 04/26/2024

4769881 Lube Oil Gallery Sight Glass Has an Air Bubble in it 04/26/2024

4772605 DIS 050002 RPS Box Light Flickering After Calibration 05/07/2024

Procedures DIS 026305 Unit 2 ATWS RPT/ARI and ECCS Level MTU and 27

STU Channel Functional Test

DIS 050002 Reactor Vessel Low Water Level Scram and Low Low Water 58

Level Isolation MTU/STU Channel Calibration and

Functional Test

DIS 130007 Unit 3 Isolation Condenser Steam/Condensate Line High 31

Flow Calibration

DIS 150005 Division I and II Low Pressure Coolant Injection ECCS 37

Initiation Circuitry Logic System Functional Test

DOS 110004 Standby Liquid Control System Quarterly/Comprehensive 55

Pump Test for the Inservice Testing (IST) Program

Work Orders 0552834601 D3 QTR TS Iso Cond Steam and Cond Line Hi Flow Cal 06/26/2024

154939301 MM D3 16Y TS/IST Disassemble/ Insp 31501-65C (ISI/ANI) 05/20/2024

154939302 OP PMT 3C LPCI Pmp Min Flow Byp Ck Vlv 05/23/2024

(Fill/Vent/Run/Final Vent)

1905669 8Y PM Inspect 4kv Bkr UTC 0002061849 03/26/2024

1912653 D2/3 8R PM Inspect Cubicle 1 at Bus 40 (Bus Tie to Bus 03/26/2024

331)

2762501 EM D3 8Y PM 4KV Cub Insp Bus 34 Cub 8: 3D CCSW Pmp 05/21/2024

2762502 OP Rack Out/ In Bus 34 Cub 8: 3D CCSW Pmp + PMT 05/22/2024

2763901 0A 8Y PM Test 4KV Bus 341 Feed to 3D LPCI PP Relays 05/21/2024

2763902 Ops Rack Out/In 3D LPCI PP Bkr for OAD Relay Routines + 05/22/2024

PMT

469762301 EM D2/3 12Y EDG Replace ASR2 Relay 03/29/2024

Inspection Type Designation Description or Title Revision or

Procedure Date

469762303 Ops PMT 2/36601-ASR2/-ASR3, 2/3 EDG Emerg Auto Start 03/27/2024

Relays

4792921 D3 6Y PM Standby Diesel Generator Inspection 04/26/2024

516522001 EM D3 4Y EQ GE 3D LPCI Pmp Motor Surv 5/22/2024

516522002 OP Perform PMT on 3D LPCI Motor 05/22/2024

299164 D2/3 2Y PM Overhaul Valve 03/27/2024

530758401 EM D3 2Y PM Insp Diesel Generator 04/25/2024

530758404 OP Support D3 2Y PM Insp Diesel Generator Overspeed 04/26/2024

Checks

5308257 CR MM-D3 2Y Com Replace Air Start Regulating Valve on 04/26/2024

EDG

5364448 D2/3 1Y PM D/G Insp/Clean Ht Exchanger 03/26/2024

5364449 D2/3 1Y PM D/G Insp/Clean Ht Exchanger 03/26/2024

21154 D3 1M TS (IST) Unit Diesel Generator Operability 04/26/2024

554739701 MM Replace U2 Air Start Motors 06/11/2024

554739702 Ops PMT Unit 2 EDG Air Start Motors/Start Solenoid 06/11/2024

554739705 EM Replace D/G Air Start Motor Solenoid 26699-103 06/11/2024

97566901 MM D3 18Y PM Diesel Generator, Overhaul Internal Seals 04/26/2024

97566905 OP Support Power Pack Break In 04/26/2024

71114.06 Miscellaneous Dresden 2Q2024 FAD 05/02/2024

24 Dresden Station Emergency Preparedness Drill Guide 06/25/2024

71152A Calculations CMED057854 Evaluation of the Use of Banana Jack Adapters in Harsh 1

Environments

Corrective Action 1057049 Air Void U2 HPCI Discharge Piping Above Acceptance 04/15/2010

Documents Criteria

4718861 Air Void Identified in U2 HPCI During 1M Periodic 11/20/2023

Verification

4763657 Resolution to Air Void in U2 HPCI Discharge Piping 04/04/2024

Engineering 379781 Evaluation of Air Identified in U2 HPCI Discharge Line 2

Changes

Miscellaneous Evaluation 77186 Commercial Grade Dedication Requirements for 0

CAT ID 425092

Evaluation 86526 Commercial Grade Dedication Acceptance Requirements for 0

Inspection Type Designation Description or Title Revision or

Procedure Date

CID 424642

Receipt 205551 Quality Receipt Inspection Package for Adapter, Banana 2/20/2015

Catalog ID Jack, 832 Terminal Strip

24642

Receipt 205694 Quality Receipt Inspection Package for 1032 Banana Jack 2/28/2015

Catalog ID Adapter

25092

Procedures DOS 140007 ECCS Venting 38

DOS 230003 High Pressure Coolant Injection System Operability and 120

Quarterly IST Verification Test

N-C0057 Torque Requirements 2

SM-AA300 Procurement Engineering Support Activities 6

SM-AA3001001 Procurement Engineering Process and Responsibilities 17

Work Orders 533460041 Perform NDE of ECCS in Support of ECCS Venting 11/15/2023

5410041 D2 31D TS HPCI Disch Piping Water Solid Verification 11/20/2023

71152S Corrective Action 4721719 IEMA Question Wording in TRM 3.7.j vs Fire Impairment 12/05/2023

Documents 4775724 3.3.e Required Actions Not Met 5/22/2024

4776320 Trend IR: Fire Protection Performance 05/24/2024

Corrective Action 4716076 Combustible Material Found in Under Unit 2 RB 517 11/07/2023

Documents Stairway

Resulting from 4716390 Combustible Materials Under Stairway 11/08/2023

Inspection 4765553 NRC Observation Follow Up 04/11/2024

Procedures CC-AA211 Fire Protection Program 9

OP-AA201007 Fire Protection System Impairment Control 2

Work Orders 505998022 Ops Prepare XL3 System for Maintenance + PMT 12/05/2023

71153 Engineering 640811 HPCI Calculation Updates Due to HPCI Gas Void Evaluation 0

Changes

Miscellaneous DRE240002 HPCI Air Void Operability HYTRAN Analysis 0

DRE240003 HPCI Air Void Operability RELAP Analysis 0

31