IR 05000390/2024001

Integrated Inspection Report 05000390/2024001 and 05000391/2024001

ML24134A063
Person / Time
Site:	Watts Bar
Issue date:	05/14/2024
From:	Louis Mckown NRC/RGN-II/DRP/RPB5
To:	Jim Barstow Tennessee Valley Authority
References
IR 2024001, EA-24-032
Download: ML24134A063 (34)

Text

SUBJECT:

WATTS BAR NUCLEAR PLANT - INTEGRATED INSPECTION REPORT 05000390/2024001 AND 05000391/2024001

Dear Jim Barstow:

On March 31, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Watts Bar Nuclear Plant. On April 19, 2024, the NRC inspectors discussed the results of this inspection with Tony Williams and other members of your staff. The results of this inspection are documented in the enclosed report.

Nine findings of very low safety significance (Green) are documented in this report. Nine 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.

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 II; the Director, Office of Enforcement; and the NRC Resident Inspector at Watts Bar Nuclear Plant.

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 II; and the NRC Resident Inspector at Watts Bar Nuclear Plant.May 14, 2024 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, Louis J. McKown, II, Chief Reactor Projects Branch #5 Division of Reactor Projects Docket Nos. 05000390 and 05000391 License Nos. NPF-90 and NPF-96

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000390 and 05000391

License Numbers: NPF-90 and NPF-96

Report Numbers: 05000390/2024001 and 05000391/2024001

Licensee: Tennessee Valley Authority

Facility: Watts Bar Nuclear Plant

Location: Spring City, Tennessee

Inspection Dates: January 01, 2024 to March 31, 2024

Inspectors: W. Deschaine, Senior Resident Inspector J. Hickey, Senior Project Engineer N. Lacy, Operations Engineer R. Wehrmann, Resident Inspector

Approved By: Louis J. McKown, II, Chief Reactor Projects Branch #5 Division of Reactor Projects

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Watts Bar Nuclear Plant, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

Inadequate Procedural Guidance for Loss of Control Room Envelope.

Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.1] - 71111.01 NCV 05000390,05000391/2024001-01 Resources Open/Closed The inspectors identified a Green finding and associated NCV of Technical Specification 5.7.1.1 a. Procedures for the licensee's failure to develop adequate procedural guidance for Annunciator Response Instruction 1-ARI-102-108 CVCS & HVAC. Specifically, the Licensee failed to ensure that immediate and long-term operational actions were incorporated for a loss of Control Room Envelope.

Failure to Maintain Configuration Control of Scaffolding in the Boron Injection Tank Rooms Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71111.04 Systems NCV 05000390,05000391/2024001-02 Conservative Open/Closed Bias The inspectors identified a Green finding and associated NCV of Title 10 CFR 50 Appendix B Criterion V, Procedures, for the licensee's failure to adequately implement the requirements of MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure. Specifically, the licensee failed to ensure that the requirements of Section 3.3.8 "Long Term Scaffolds" were met for scaffolds installed in the Unit 1 and Unit 2 Boron Injection Tank Rooms.

Failure to Implement Fire Protection Program Requirements for Turbine Building Crane Upgrade Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.11] - 71111.05 NCV 05000390,05000391/2024001-03 Challenge the Open/Closed Unknown The inspectors identified a Green finding and associated NCV of T.S. 5.7.1.1 d. Fire Protection Program implementation, for failure to control transient combustibles within the limits or evaluate the impact of transient combustibles above the limit defined in NPG-SPP-18.4.7 and failure to implement NPG-SPP-18.4.6 Control of Fire Impairments, for the licensee's failure to prevent fire protection features from being blocked by scaffolding or obtain a fire impairment.

Failure to Implement Fire Protection Program Requirements in Boron Injection Tank rooms Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.14] - 71111.05 NCV 05000390,05000391/2024001-04 Conservative Open/Closed Bias The inspectors identified a Green finding and associated NCV of Technical Specification 5.7.1.1.d. Fire Protection Program implementation of NPG-SPP-18.4.7 Control of Transient Combustibles, for the licensee's failure to prevent the addition of transient combustibles into Risk Level 1 Areas without a Transient Combustible Permit/Evaluation.

Failure to Implement NPG-SPP-18.4.7 in the IPS and Auxiliary Building Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.5] - Work 71111.05 NCV 05000390,05000391/2024001-05 Management Open/Closed The inspectors identified a Green finding and associated NCV of TS 5.7.1.1 d. Fire Protection Program implementation, for failure of the licensee to ensure that transient combustible were controlled in accordance with the requirements of NPG-SPP-18.4.7, Control of Transient Combustibles. Specifically, transient combustibles were stored in excess of the permitted amounts in the following areas: Intake Pumping Station (IPS), Elevation 713' - Unit 1 Lower Reactor Building Access Room, Elevation 713' - Unit 2 Lower Reactor Building Access Room,

Elevation 713' - Unit 1 Penetration Room, Elevation 713' - Unit 2 Penetration Room, and Elevation 757' - Unit 2 Upper Reactor Building Access Room.

Failure to Implement Requirements of MMTP-102 in the A train ERCW Strainer Room Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71111.05 Systems NCV 05000390,05000391/2024001-06 Conservative Open/Closed Bias The inspectors identified a Green finding and associated NCV of 10 CFR 50, Appendix B,

Criterion V, Instructions, Procedures, and Drawings. Specifically, the licensee failed to implement the requirements of MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure so as to meet the requirements of section 3.3.8,

Requirements for Long Term Scaffolds.

Failure to implement the requirements of MMTP-102 for scaffolding constructed near the Main Control Room Chillers.

Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.11] - 71111.13 NCV 05000390,05000391/2024001-07 Challenge the Open/Closed Unknown The inspectors identified a Green finding and associated NCV of 10 CFR 50, Appendix B,

Criterion V, Instructions, Procedures, and Drawings. Specifically, the licensee failed to implement the requirements of MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure. This resulted in configurations that challenged the reasonable assurance that the Main Control Room Chillers could perform their credited functions.

Failure to Identify Condition Adverse to Quality with the Lower Inlet Doors Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [P.2] - 71111.20 NCV 05000391/2023004-01 Evaluation Closed EA-24-032 The inspectors identified a Green finding and an associated NCV of 10 CFR 50 Appendix B Criterion XVI, Corrective Actions, for failure to promptly identify and correct the impact of Unit feedwater leakage on ice condenser lower inlet doors. This condition led to the accumulation of ice on the lower inlet doors challenging their ability to open.

Failure to Implement Requirements of Plant Modification Process Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.13] - 71111.24 NCV 05000390,05000391/2024001-09 Consistent Open/Closed Process The inspectors identified a Green finding and associated NCV of Title 10 CFR Part 50 Appendix B Criterion III, Design Control for failure to implement the plant modification process. Specifically, a Control Room Emergency Ventilation System door dog was modified without an approved Plant Modification.

Additional Tracking Items

Type Issue Number Title Report Section Status URI 05000390,05000391/20 URI For EDG Governor 71111.15 Open 24001-08 Failure

PLANT STATUS

Unit 1 operated at or near rated thermal power for the entire inspection period.

Unit 2 began the inspection period at or near rated thermal power. Unit 2 experienced a malfunction of the Main Generator Protective relay on January 27, 2024. This malfunction caused the Main Turbine to trip which resulted in an automatic trip of the reactor. The unit was returned to rated thermal power on January 31, 2024, and remained at or near rated thermal power until March 05, 2024. Unit 2 experienced a human performance induced actuation of the Feedwater Isolation System on March 05, 2024. This malfunction caused the low Steam Generator water level which resulted in an automatic trip of the reactor. The unit was returned to rated thermal power on March 07, 2024, and remained at or near rated thermal 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

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 (snow storm) with extended temperatures below freezing on January 18, 2024.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (3 Samples)

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

(1) 1A emergency diesel generator (EDG) on February 1, 2024

(2) 2AA motor driven auxiliary feedwater pump on February 7, 2024

(3) 1B-B containment spray pump on February 26, 2024

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 Samples)

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

(1) Intake pumping station on January 12, 2024

(2) 1A-A EDG and 2A-A EDG on January 31, 2024

(3) Aux building 737' elevation on February 21, 2024

(4) Unit 1 control rod drive equipment room, pressurizer heater transformer room, and miscellaneous equipment room (auxiliary building elevations 782' and 786') on February 26, 2024.

(5) Auxiliary building, elevation 729' on February 28, 2024.

Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the on-site fire brigade training and performance during an announced fire drill on January 31, 2024, and February 7, 2024.

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (2 Samples)

(1) The inspectors evaluated internal flooding mitigation protections in the auxiliary building. Elevations 713', 692', and 676' on February 26, 2024, through February 28, 2024.

(2) The inspectors evaluated internal flooding mitigation protections in the auxiliary building, elevation 737', on March 18 thru 20, 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 a Unit-2 reactor startup, turbine roll, and synchronizing of the main generator to the electrical grid on January 30 and 31, 2024.

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

(1) LOR week of March 11, 2024. The inspectors observed and evaluated as-found performance of LOR OPL 373 SEG # 3-OT-SRE-1002 Rev. # 10U1 in the simulator on March 12, 2024.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (1 Sample)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) Failure of safety related emergency gas treatment system, A train room cooler to start on receipt of an auxiliary building isolation signal, as documented in CR 1859917 and troubleshooting under WO 13775043.

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1) Risk management activities for the 2A-A EDG outage during the week of February 12, 2024

(2) Risk management activities for the B-B main control room chiller outage during the week of February 19, 2024

(3) Risk management activities for reactor coolant system loop 3 wide range transmitter calibration on March 04, 2024.

(4) Risk management activities for the A-A main control room chiller outage during the week of March 11, 2024.

(5) Risk management activities for the Yellow Risk window on March 12, 2024.

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) CR1901361, Loss of Unit-1 Shutdown Bank B Rod G-13 Individual Rod Position Indication on January 04, 2024

(2) CR1902969, Loss of Unit-2 2A-A Containment Air Return Fan Due to Blown Control Power Fuse on January 14, 2024

(3) CR1907378, 125 Volt Battery V Flame Arrestor Requires Replacement on February 8, 2024

(4) CR1907406, Safety Injection Accumulator Level Indicator WBN-2-LI-063-0082 Deviation on February 9, 2024

(5) Operability Assessment for 1A-A, 1B-B, and 2B-B EDGs Due to Governor Failure on the 2A-A EDG on February 15, 2024

(6) CR 1911472, Low Voltage Alarm on Battery Charger 7-2 on February 22, 2024

(7) CR 1911486, Cracks Found on Vital Battery IV on February 23, 2024

(8) CR 1916514, while running 2A-A EDG, two inlet air dampers failed to open on March 13, 2024

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (2 Samples)

(1) The inspectors evaluated forced outage activities from January 27, 2024 to January 31, 2024.

(2) The inspectors evaluated forced outage activities from March 5, 2024 to March 7, 2024.

71111.24 - Testing and Maintenance of Equipment Important to Risk

The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:

Post-Maintenance Testing (PMT) (IP Section 03.01) (6 Samples)

(1) WBN-2FCV-003-0048A, SG#2 Inlet Flow Control Valve Bypass Valve Dual Indication under WO 124268121

(2) Vital inverter 0-VI 10-year overhaul under WO 120804885

(3) 2A-A EDG PMT run for post component outage on February 15, 2024

(4) B-B MCR chiller component outage on post maintenance testing on February 29, 2024

(5) Control room emergency ventilation system access door dog replacement, post leak test failure on March 5, 2024

(6) A-A MCR chiller component outage post maintenance testing on March 21, 2024.

Surveillance Testing (IP Section 03.01) (5 Samples)

(1) C-S component cooling system pump quarterly surveillance on February 8, 2024, under WO 123767867

(2) 2A-A EDG quarterly surveillance on February 16, 2024

(3) 1B-B RHR pump quarterly on February 21, 2024

(4) Functional test of SSPS Train A and reactor trip breaker A on February 28, 2024

(5) CREVS surveillance testing on March 5, 2024

71114.06 - Drill Evaluation

Additional Drill and/or Training Evolution (1 Sample)

The inspectors evaluated:

(1) Elevated dose equivalent iodine levels in RCS, 2 dropped rods, anticipated transient without scram, steam generator tube rupture, faulted steam generator power operated relief valve on March 27,

OTHER ACTIVITIES - BASELINE

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

(1) The inspectors evaluated reactor trip due to main generator protective relay actuation and licensees performance on January 27, 2024.

(2) The inspectors evaluated reactor trip due to inadvertent feedwater isolation and licensees performance on March 5,

INSPECTION RESULTS

Inadequate Procedural Guidance for Loss of Control Room Envelope.

Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.1] - 71111.01 NCV 05000390,05000391/2024001-01 Resources Open/Closed The inspectors identified a Green finding and associated NCV of Technical Specification 5.7.1.1 a. Procedures for the licensee's failure to develop adequate procedural guidance for Annunciator Response Instruction 1-ARI-102-108 CVCS & HVAC. Specifically, the Licensee failed to ensure that immediate and long-term operational actions were incorporated for a loss of Control Room Envelope.

Description:

On January 18, 2024 at 07:51 Watts Bar was in mode 1 at 100% power and received main control room alarms 105-B and 106-B [MCR HVAC System A/B Abnormal]. These alarms are caused by control room differential pressure going below 0.2 in H2O. Licensee Procedure 1-ARI-102-108 "HVAC and CVCS" Rev 0020 contains directions for response to Annunciators 105-B "MCR HVAC System A Abnormal" and 106-B "MCR HVAC System B Abnormal". The annunciator response instruction (ARI) also provides the setpoint information on what brings in these annunciators, "Less than or equal to 0.2 in WC positive pressure in the MCR with the AHU Running". The ARI lists the discrete probable causes and their corrective actions for the loss of positive pressure in the main control room.

The inspectors, on January 18, brought to the licensees attention that this ARI does not contain any direction for immediate operator actions or long-range actions required to mitigate the consequences of an associated event. The inspectors further provided that Section 5 of Regulatory Guide 1.33, Revision 2, Appendix A, incorporates this as a license requirement in accordance with TS 5.7.1.1.a.

Based on indications observed on January 18, the station declared entry into TS LCO 3.7.10, Control Room Emergency Ventilation System (CREVS), action B for one or more trains inoperable due to inoperable control room envelope (CRE) boundary. Action B.1. directs operators to "Initiate action to implement mitigating actions with a completion time of Immediately." These mitigating actions are the actions necessary to ensure that CRE occupant exposure to radiological and chemical hazards will not exceed limits. At 15:42 licensee staff wrote CR 1903907 to document that they were unable to locate procedural guidance on the mitigating actions for the loss of the CRE. Licensee Procedure 0-TI-5 Ventilation Testing Program defines the CRE as follows: The Control Room Envelope (CRE)is the plant area defined in FSAR section 6.4, Habitability Systems, that in the event of an emergency, it can be isolated from the plant areas and the environment external to the CRE.

This area is served by an emergency ventilation system with the intent of maintaining the habitability of the control room." Troubleshooting revealed that the Main Control Room Outside Air intake grating was covered in ice and snow that was subsequently cleared allowing pressurization of the CRE.

Corrective Actions: Licensee ensured that potassium iodide (KI) tablets were available and that self contained breathing apparatuses (SCBAs) were staged for operators. Additionally, the licensee documented the issue in the Corrective Action Program.

Corrective Action References: CR 1903907, 1923543

Performance Assessment:

Performance Deficiency: The lack of procedural guidance to complete TS immediate actions is the performance deficiency reasonably within the licensee's ability to foresee and prevent.

Specifically, the licensee failed to provide procedural guidance to implement mitigating actions during a loss of control room envelope (CRE).

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Procedure Quality attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, lack of procedural guidance challenges the ability to ensure that CRE dose remains less than requirements. Additionally, the lack of pre-planned procedural guidance challenges the reasonable assurance that implementation of compensatory actions can be reliably preformed during a design bases event. This is similar to example 3.g from IMC 0612 Appendix E.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 3, Mitigating Systems Screening Questions, Section A, the screening questions, were all answered "NO", therefore, the inspectors determined the finding was of very low safety significance (Green).

Cross-Cutting Aspect: H.1 - Resources: Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety.

Specifically, the failure to ensure procedures and materials were in place directly challenged the operating crew's ability to implement and verify required mitigating actions.

Enforcement:

Violation: TS 5.7.1.1 a. requires that "Written procedures shall be established, implemented, and maintained covering the following activities: a. The applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978."

Regulatory Guide 1.33, Revision 2, Section 5. Procedures for Abnormal, Off-normal, or Alarm Conditions states, in part, that "Each safety related annunciator should have its own written procedure, which should normally contain...

(4) the immediate operation action, and

(5) the long-range actions."

TS LCO 3.7.10 Action B states, in part, that "B.1 Initiate action to implement mitigating actions with a completion time of immediately, AND B.2 Verify mitigating actions ensure CRE occupant exposures to radiological and chemical hazards will not exceed limits and CRE occupants are protected from smoke hazards with a completion time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />."

Contrary to the above, since implementation of 1-ARI-102-108 until present, the licensee failed to establish written procedures associated with safety related annunciators, 105-B MCR HVAC System A Abnormal and 106-B MCR HVAC System B Abnormal, containing the immediate operation action and long-range actions. Specifically, this prevented the implementation and verification of mitigating actions to ensure CRE occupant exposures to radiological and chemical hazards will not exceed limits and CRE occupants are protected from smoke hazards.

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

Failure to Maintain Configuration Control of Scaffolding in the Boron Injection Tank Rooms Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71111.04 Systems NCV 05000390,05000391/2024001-02 Conservative Open/Closed Bias The inspectors identified a Green finding and associated NCV of Title 10 CFR 50 Appendix B Criterion V, Procedures, for the licensee's failure to adequately implement the requirements of MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure. Specifically, the licensee failed to ensure that the requirements of Section 3.3.8 "Long Term Scaffolds" were met for scaffolds installed in the Unit 1 and Unit 2 Boron Injection Tank Rooms.

Description:

On February 26, 2024, and February 27, 2024, inspectors identified multiple scaffolds constructed in the Unit 1 and Unit 2 boron injection tank rooms. The scaffolds constructed in these rooms were originally constructed during the unit refueling outages greater than 90 days prior to inspector discovery. The inspectors found that some of these scaffold dated back to at least October of 2022 based upon review of upon review of plant walkdown information.

Licensee Procedure MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure, Section 3.3.8 Requirements for Long Term Scaffolds C.

states, in part that, "Any scaffold remaining in the plant for longer than 90 days that do not meet the requirements of Section 3.3.8 are not designated as a long term scaffold. This scaffolding is required to have an evaluation by Site Engineering, a 10CFR50.59 evaluation and a designated removal date. Scaffolds left in-place for greater than two years must be modified to comply with Section 3.3.8 or be removed."

MMTP-102, Section 3.3.1, General Seismic Qualifications, B. states, in part, "If scaffolding is to be in place during plant operation, and it is located adjacent to safety-related or Trip-Sensitive equipment, it shall be constructed to comply with these guidelines or designed such that the seismic event will not impact the equipment or system required for that particular mode of operation."

Section 3.3.1 D. states, "Scaffolding and their horizontal restraints shall maintain a minimum clearance of four

(4) inches from all plant systems, components, or equipment; except as noted below."

Section 3.3.1 D.4. states, "If the required clearance cannot be physically achieved, Site Engineering (SE) evaluation and approval is required for that portion in which the clearance cannot be achieved. The SE evaluation and approval shall be documented on Attachment 6 or Attachment 7."

The site engineering evaluations for these scaffolds did not provide sufficient analysis, detail, or any technical justification to demonstrate that there was no adverse impact to the safety related systems in the rooms. For the scaffolds identified there neither were 50.59 evaluations prepared, nor were designated removal dates associated with scaffolds. Additionally, many of the discovered scaffolds in the Unit 1 and Unit 2 boron injection tank rooms were constructed without maintaining the separation requirements associated with safety related and trip-sensitive equipment of MMTP-102 Section 3.3.

Corrective Actions: Licensee removed the non-compliant scaffolding and documented the issues in the Corrective Action Program.

Corrective Action References: CR 1917019, CR 1923535

Performance Assessment:

Performance Deficiency: The licensees failure to implement their scaffold program in accordance with established procedures or guidance was a performance deficiency reasonably within their ability to foresee and prevent. Specifically, Watts Bar demonstrated with a multitude of examples their failure to affect their scaffold or 10CFR50.59 programs within the Unit 1 and Unit 2 BIT rooms.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Configuration Control 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. For the many scaffolds discovered by the inspectors within the Unit 1 and Unit 2 BIT rooms, the licensee did not perform engineering or 10CFR50.59 evaluations for scaffolding installed greater than 90-days as well as for those scaffolds adjacent to safety related and trip sensitive equipment to assess their impact upon the stations reliability and capability to respond to initiating events. This issue is similar to example 3.k. in IMC 0612 App E.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 2, Mitigating Systems Screening Questions, Section A, the screening questions, were all answered a NO; therefore, the inspectors determined the finding was of very low safety significance (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, failure to ensure that the required evaluations were completed resulted in configurations that challenged the reasonable assurance that the equipment in the BIT rooms was not adversely affected.

Enforcement:

Violation: 10 CFR 50 Appendix B Criterion V Instructions, Procedures, and Drawings, states, in part, "Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings."

TVA-NQA-PLN89-A section 7.2.7 Design Changes E. states, in part, that: "Measures to control plant configuration and ensure that the actual plant configuration is accurately depicted on drawings and other appropriate design output documents and reconciled with the applicable design basis shall be established, documented, and implemented."

Contrary to the above from October 2022 to March 26, 2024, the licensee failed to implement the requirements of MMTP-102, a quality related procedure. Specifically, the licensee failed to ensure that actual plant configuration was controlled and reconciled with the applicable design basis.

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

Failure to Implement Fire Protection Program Requirements for Turbine Building Crane Upgrade Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.11] - 71111.05 NCV 05000390,05000391/2024001-03 Challenge the Open/Closed Unknown The inspectors identified a Green finding and associated NCV of T.S. 5.7.1.1 d. Fire Protection Program implementation, for failure to control transient combustibles within the limits or evaluate the impact of transient combustibles above the limit defined in NPG-SPP-18.4.7 and failure to implement NPG-SPP-18.4.6 Control of Fire Impairments, for the licensee's failure to prevent fire protection features from being blocked by scaffolding or obtain a fire impairment.

Description:

On January 12, 2024, inspectors identified the staging of transient combustibles on elevation 755' of the turbine building, the area located just outside of the Unit 1 Main Control Room Access door. The inspectors reviewed the documentation at the job site for transient combustibles. The transient combustible evaluation stated that there were 0 BTU of material added to the space. Upon review of the materials in the area, the combustibles exceeded the NPG-SPP-18.4.7 limits for the turbine building of 25 lbs. The transient combustibles were staged for implementation of the turbine building crane upgrade project.

The transient combustibles consisted of, a hybrid diesel electric man-lift, rolls of fall protection netting, lumber, and spill catches. The inspectors notified the shift manager; this was documented in CR 1902773. On February 1, 2024, the inspectors observed that the transient combustible permit for the turbine building elevation 755' was not accurate for the materials present at the job site. The licensee performed a new evaluation of the job site and a new transient combustible permit was issued; this was documented in CR 1907348. NPG-SPP-18.4.7 implements the Transient Combustible Controls Program for the TS 5.7.1.1.d Fire Protection Program.

On January 31, 2024, inspectors identified fire protection features (1 hose cart, 1 hose station, 2 fire extinguishers, and 1/2-MI-0.047 APP R equipment) blocked by scaffolding on turbine building elevation 755'. This issue was communicated to licensee staff and was documented in CR 1907348 on February 1, 2024. NPG-18.4.6, Control of Fire Protection Impairments, section 3.2.1 A.4 states, in part, that the following are examples of activities that may cause fire protection impairment, "scaffolds that block access to fire hose stations, and fire extinguishers."

Corrective Actions: Licensee evaluated the increased combustible loading, reconfigured the scaffolding, and documented the issues in the Corrective Action Program.

Corrective Action References: CR 1902773, CR 1907348, 1907242

Performance Assessment:

Performance Deficiency: The inspectors determined that the licensees failure to adequately implement the requirements the Fire Protection Program was a performance deficiency.

Specifically, the licensee failed to identify and evaluate transient combustibles introduced into the turbine building in excess of the amounts allowed per NPG-SPP-18.4.7. Moreover, the licensee constructed a scaffold blocking access to fire protection features without obtaining a fire impairment.

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 fire loading was not within the fire hazard analysis limits. This issue is similar to IMC 0612, Appendix E, Examples of Minor Issue, Example 4.j since the fire loading was not within the fire hazard analysis limits.

Furthermore, the licensee procedure requirements were not met and the as left condition would have affected a fire response in the area due to impairing access to either an attack or cover hose.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The finding screened to very low safety significance (Green) based on association with fire prevention and administrative controls and question 1.4.1-A was answered No - Screen to Green, because the finding did not result in a more significant fire than previously analyzed.

Cross-Cutting Aspect: H.11 - Challenge the Unknown: Individuals stop when faced with uncertain conditions. Risks are evaluated and managed before proceeding. Specifically, licensee staff normalized the non-conformances based on the fact that the area is well traveled as it is the typical access path for the Main Control Rooms and the project was being worked under the Work Control Processes.

Enforcement:

Violation: Unit 1 and Unit 2 Technical Specifications 5.7.1.1 d., requires, in part, that "written procedures shall be implemented for the Fire Protection Program implementation."

Contrary to the above, from January 12, 2024, to February 1, 2024, the licensee failed to implement written procedures for the Fire Protection Program implementation. Specifically, the licensee did not implement NPG-SPP-18.4.7 based on the transient combustible controls established at turbine building elevation 755'. Additionally, the licensee did not implement NPG-18.4.6 based upon their impairment of equipment required to respond to a fire event also on turbine building 755.

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

Failure to Implement Fire Protection Program Requirements in Boron Injection Tank rooms Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.14] - 71111.05 NCV 05000390,05000391/2024001-04 Conservative Open/Closed Bias The inspectors identified a Green finding and associated NCV of Technical Specification 5.7.1.1.d. Fire Protection Program implementation of NPG-SPP-18.4.7 Control of Transient Combustibles, for the licensee's failure to prevent the addition of transient combustibles into Risk Level 1 Areas without a Transient Combustible Permit/Evaluation.

Description:

On February 26, 2024, inspectors identified transient combustible materials in the Unit 1 boron injection tank (BIT) room. The transient combustible materials consisted of plywood wrapped in plastic sheeting, hoses going to drain funnels, fiberglass ladders, extension cords, temporary lighting, and fall protection harnesses. The inspectors communicated this issue of concern to licensee staff who documented it in CR 1912722. On February 27, 2024, inspectors identified transient combustible materials in the Unit 2 BIT Room. The materials consisted of more than 5 hoses running to a drum on the floor, fiberglass ladders, extension cords, fall protection harnesses, and temporary lighting. The inspectors communicated this issue to licensee staff who then documented both the unit 1 &

2 BIT room issues in CR 1913188 on February 27, 2024.

The Unit 1 &2 BIT rooms are 713.0-A28 and 713.0-A29 respectively. The Watts Bar fire protection program classifies these spaces as Risk Level 1 as both trains of multiple emergency core cooling systems are present within each room.

NPG-SPP-18.4.7, Control of Transient Combustibles, Section 3.4.2 states: "Risk Level 1 Fire Areas must meet the following requirements: Staging or storing of transient combustible materials, outside of closed metal containers, is not allowed in Fire Risk Level 1 Fire Areas, unless: Transient Combustible Permit/Evaluation, with appropriate compensatory measure or engineering evaluation, is performed for any transient combustible material introduced to these areas that are not either A. In-Use and constantly attended (as defined by this procedure) or B. Staged/stored in a closed metal container."

Corrective Actions: Transient combustibles were removed from the BIT rooms and transient combustible evaluations were performed.

Corrective Action References: CR 1913188, 1912722

Performance Assessment:

Performance Deficiency: Failure to implement the requirements of NPG-SPP-18.4.7, Control of Transient Combustibles, was a performance deficiency reasonably within the ability to foresee and prevent. Specifically, this procedure prohibits the addition of transient combustibles into Risk Level 1 Areas such as the unit 1 & 2 BIT rooms without a transient combustible evaluation and permit.

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 addition of transient combustibles required additional evaluation to demonstrate that the Fire Safe Shutdown Strategy was not adversely impacted. This issue is similar to example 4.j. of IMC 0162 Appendix E.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. Specifically, Step 1.4.1-A is answered No, based on the fact that the finding did not result in a more significant fire than previously analyzed.

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, failure to evaluate the addition of transient combustibles into Risk Level 1 zones resulted in direct challenges to the Appendix R Safe Shutdown Strategy.

Enforcement:

Violation: Unit 1 and Unit 2 Technical Specifications 5.7.1.1 d., requires, in part, that "written procedures shall be implemented for the fire protection program implementation."

Contrary to the above, from February 26, 2024, to March 7, 2024, the licensee failed to implement written procedures for the Fire Protection Program implementation. Specifically, the licensee failed to prevent the introduction of transient combustibles the Unit 1 & 2 BIT rooms without evaluation and permit.

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

Failure to Implement NPG-SPP-18.4.7 in the IPS and Auxiliary Building Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.5] - Work 71111.05 NCV 05000390,05000391/2024001-05 Management Open/Closed The inspectors identified a Green finding and associated NCV of TS 5.7.1.1 d. Fire Protection Program implementation, for failure of the licensee to ensure that transient combustible were controlled in accordance with the requirements of NPG-SPP-18.4.7, Control of Transient Combustibles. Specifically, transient combustibles were stored in excess of the permitted amounts in the following areas: Intake Pumping Station (IPS), Elevation 713' - Unit 1 Lower Reactor Building Access Room, Elevation 713' - Unit 2 Lower Reactor Building Access Room, Elevation 713' - Unit 1 Penetration Room, Elevation 713' - Unit 2 Penetration Room, and Elevation 757' - Unit 2 Upper Reactor Building Access Room.

Description:

On January 12, 2024, inspectors identified un-attended transient combustibles stored under the stair well in the A Train ERCW strainer room. The estimated mass of transient combustibles exceeded the limits of NPG-SPP-18.4.7.

Licensee Procedure NPG-SPP-18.4.7 Rev 0018, Control of Transient Combustibles, defines the IPS as a Level 2 Risk Area and Section 3.4.3 A. states, in part, that: 1. The introduction of transient combustible materials is allowed, without a permit or evaluation, if materials are 1)

In Use, 2) Staged, 3) Stored in a metal container, or 4) will be limited to less than 25 pounds of combustibles and stored greater than 20 feet from other staged/stored transient combustibles. 2. Transient Combustible Permit with appropriate compensatory measure (functional suppression and detection within the area, or hourly fire watch) or engineering evaluation is required, if the conditions described above cannot be met. NPG-SPP-18.4.7 section 3.2.1 E. states "Combustibles stored in stairwells or behind stairways is prohibited due to potential life safety concerns."

On February 27, 2024, inspectors identified un-attended transient combustibles stored in the Unit 1 lower reactor building access room. The estimated mass of combustibles was in excess of the limits for a Risk Level 3 zone.

On February 27, 2024, inspectors identified un-attended transient combustibles stored in the Unit 2 lower reactor building access room. The estimated mass of combustibles was in excess of the limits for a Risk Level 3 zone.

On February 27, 2024, inspectors identified un-attended transient combustibles stored in the Unit 1 penetration room. The estimated mass of combustibles was in excess of the limits for a Risk Level 1 zone.

On February 27, 2024, inspectors identified un-attended transient combustibles stored in the Unit 2 penetration room. The estimated mass of combustibles was in excess of the limits for a Risk Level 1 zone.

On February 27, 2024, inspectors identified un-attended transient combustibles stored in the Unit 2 upper reactor building access room. The estimated mass of combustibles was in excess of the limits for a Risk Level 1 zone.

NPG-SPP-18.4.7 Section 3.4.2 states: "Risk Level 1 Fire Areas must meet the following requirements: Staging or storing of transient combustible materials, outside of closed metal containers, is not allowed in Fire Risk Level 1 Fire Areas, unless: Transient Combustible Permit/Evaluation, with appropriate compensatory measure or engineering evaluation, is performed for any transient combustible material introduced to these areas that are not either A. In-Use and constantly attended (as defined by this procedure) or B. Staged/stored in a closed metal container."

Additionally, NPG-SPP-18.4.7, section 3.4.4 states: "Risk Level 3 Fire Areas must meet the following requirements: 1. The introduction of transient combustible materials is allowed, without a permit or evaluation, if materials are 1) In Use, 2) Staged, 3) Stored in a metal container, or 4) will be limited to less than 100 pounds of combustibles and stored greater than 20 feet from other staged/stored transient combustibles. 2. Transient Combustible Permit with appropriate compensatory measure (functional suppression and detection within the area, or hourly fire watch) or engineering evaluation is required, if the conditions described above cannot be met."

The fire protection zones listed above, credit the control of transient combustibles in the Fire Protection Report analysis of record to demonstrate that the facility can achieve the fire safe shutdown (FSSD) condition.

Corrective Actions: Licensee removed the transient combustibles from the area.

Corrective Action References: CR 1907242, 1912814, 1912965, 1912968, 1912972

Performance Assessment:

Performance Deficiency: The inspectors determined that the licensees failure to adequately implement the requirements of NPG-SPP-18.4.7 was a performance deficiency. Specifically, from December 4, 2023 to January 12, 2024 the licensee failed to identify the transient combustibles were stored in the intake pumping station and various locations throughout the auxiliary building in excess of the amount allowed per NPG-SPP-18.4.7. NPG-SPP-18.4.7 implements the Transient Combustible Controls for the Fire Protection Program, which is a T.S. 5.7.1.1 d. required program.

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 fire loading was not within the fire hazard analysis limits. This issue is similar to IMC 0612, Appendix E, Examples of Minor Issue, Example 4.j since the fire loading was not within the fire hazard analysis limits.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. Specifically, Step 1.4.1-B screens to green based on the area affected having adequate automatic detection and suppression.

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. Specifically, the licensee failed to establish adequate work tasks to provide control of transient combustibles for work activities throughout the IPS and auxiliary building.

Enforcement:

Violation: Unit 1 and Unit 2 Technical Specifications 5.7.1.1 d. requires, in part, that written procedures shall be implemented for the Fire Protection Program implementation.

Specifically, the licensee implements control of transient combustibles via NPG-SPP-18.4.7, Control of Transient Combustibles.

Contrary to the above, from December 4, 2023, to February 28, 2024, the licensee failed to implement all provisions of the approved fire protection program. Specifically, the licensee failed to maintain rooms within the limits of the Control of Transient Combustibles procedure sections 3.4.2, 3.4.3, and 3.4.4., or obtain a Transient Combustible Permit/Evaluation form with appropriate compensatory measures and failed to ensure that transient combustibles were not stored in a stairwell.

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

Failure to Implement Requirements of MMTP-102 in the A train ERCW Strainer Room Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71111.05 Systems NCV 05000390,05000391/2024001-06 Conservative Open/Closed Bias The inspectors identified a Green finding and associated NCV of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings. Specifically, the licensee failed to implement the requirements of MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure so as to meet the requirements of section 3.3.8, Requirements for Long Term Scaffolds.

Description:

On January 12, 2024, inspectors discovered a rigging frame in the A Train ERCW Strainer Room. Upon review of the scaffold tag it was determined that the scaffold had been in place since October 9, 2023, greater than 90 days. Inspectors informed licensee staff who documented the condition in CR 1902773. The observed configuration of the rigging frame placed the end of scaffold poles within 3 of instrumentation conduit as well as within 4 of safety related piping. The scaffold poles were also within 3 of instrumentation lines the ERCW system.

MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, Revision 0023, Section 3.3.8, Requirements for Long Term Scaffoldings" states, in part, that scaffolds used as rigging frames are not eligible for long term status. Additionally, Section 3.3.8 C. requires that "[a]ny Scaffold remaining in the plant for longer than 90 days that do not meet the requirements of section 3.3.8 are not designated as a long-term scaffold. This scaffolding is required to have an evaluation by Site Engineering, a 10CFR50.59 Evaluation, and a designated removal date.

MMTP-102 Section 3.3.1 D. requires, in part, that Scaffolding and their horizontal restraints shall maintain a minimum clearance of four

(4) inches from all plant systems, components, or equipment. Additionally, D.4 states, in part that; If the required clearance cannot be physically achieved, Site Engineering (SE) evaluation and approval is required for that portion in which the clearance cannot be achieved.

During a field walkdown on January 18, 2024, inspectors once again found the rigging frame in the A Train ERCW Strainer Room. Noting that the scaffold tag appeared unchanged and presuming compliance, the inspectors brought this condition to the licensees attention while also requesting the completed evaluation by Site Engineering, a 10CFR50.59 Evaluation, and a designated removal date. Lacking the supporting documentation, the inspectors observed that Watts Bar did not screen the condition report capturing the apparent non-compliance with MMTP-102 until January 29, 2024, 17 days after discovery.

Corrective Actions: Licensee removed the scaffold and documented the procedural non-compliance in CR 1909785

Corrective Action References: CR 1902773, 1909785

Performance Assessment:

Performance Deficiency: The failure to comply with the requirements of MMTP-102 was the performance deficiency reasonably within the licensees ability to foresee and prevent.

Specifically, the rigging frame in the A Train ERCW Strainer Room remained installed in the station for greater than 90 days without an evaluation by Site Engineering, a 10CFR50.59 Evaluation, and a designated removal date.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control 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 rigging frame installed in the A Train ERCW is installed above safety related equipment and instrumentation. Additionally, the installed scaffold did not meet the separation requirements from safety related equipment and required and engineering evaluation. Failure to maintain configuration control of this area of the plant challenges the assumption of reasonable assurance that the mitigating systems functions will not be impacted. Additionally, this scenario is similar to Example 4.a of MTM in IMC 0612 "Examples of Minor Issues".

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 2, Mitigating Systems Screening Questions, Section A, the screening questions, were all answered a NO; therefore, the inspectors determined the finding was of very low safety significance (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 failed to ensure that the evaluations necessary to allow the rigging frame were completed prior to exceeding the procedural limits for installation.

Enforcement:

Violation: 10 CFR 50 Appendix B Criterion V "Instructions, Procedures, and Drawings" states, in part, that : "Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings."

MMTP-102 Rev 023, a quality related procedure, requires in part that scaffold be constructed per the requirements of the procedure or a Site Engineering evaluation be performed.

Contrary to the above, from October 9, 2023, through January 31, 2024, the licensee failed to ensure that scaffolds constructed in the A Train ERCW Strainer Room were constructed in accordance with MMTP-102 requirements or that a Site Engineering Evaluation was performed.

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

Failure to implement the requirements of MMTP-102 for scaffolding constructed near the Main Control Room Chillers.

Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.11] - 71111.13 NCV 05000390,05000391/2024001-07 Challenge the Open/Closed Unknown The inspectors identified a Green finding and associated NCV of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings. Specifically, the licensee failed to implement the requirements of MMTP-102, Erection of Scaffolds/Temporary Work Platforms and Ladders, a quality related procedure. This resulted in configurations that challenged the reasonable assurance that the Main Control Room Chillers could perform their credited functions.

Description:

On February 21, 2024, inspectors identified a scaffold pole above the A-A Main Control Room (MCR) Chiller. The scaffold pole was not installed in accordance with licensee scaffold procedures. Specifically, the scaffold pole was wedged in the spray shield of the compressor motor and suspended by a rigging strap on the opposite end. This scaffold pole was directly above the electrical termination of the oil pump for the Main Control Room Chiller. The A-A MCR Chiller was the only operable MCR Chiller at the time due to a planned maintenance outage on the B-B MCR Chiller. The scaffold pole was removed on February 22, 2024, after the inspectors reiterated that the scaffold pole was not in accordance with MMTP-102.

On March 12, 2024, inspectors identified a rigging frame without an engineering evaluation installed around the MCR Chiller and a scaffold installed greater than 90 days attached to the ERCW piping adjacent to the B-B MCR Chiller. The rigging frame was not constructed in accordance with the preapproved rigging frames in MMTP-102 and required an engineering evaluation to demonstrate that it did not impact the seismic qualification of the MCR Chiller.

The scaffold that was greater than 90 days old was secured to stainless steel piping ERCW piping for the B-B MCR Chiller and was resting against the BB MCR Chiller's chill water piping. The B-B MCR Chiller was the only operable MCR Chiller at the time due to a planned maintenance outage on the A-A MCR Chiller.

The Main Control Room Chillers are relied upon to maintain habitable conditions in the Main Control Room during normal operations and for the duration of the design bases accident scenarios.

MMTP-102 Section 5.0 defines Long Term Scaffold as: Scaffold remaining in the plant for greater than 90 days with the plant at power or for scaffold erected more than 90 days in plant areas under configuration control shall be designated as a long term scaffold.

MMTP-102 Section 3.1.1 V. states, in part, that: "Scaffold installations in Class I/Category I areas which cannot be erected according to the requirements of Section 3.3 shall be documented by type of deficiency, evaluated and approved by SE per Attachment 5 or 6." The scaffolds constructed in the vicinity of the MCR Chillers were not evaluated and approved by site engineering.

MMTP-102 Section 3.1.1 EE states, in part, that: "rigging frame installations in Class I/Category I areas must meet the requirements of Section 3.3. Rigging frames, constructed of scaffolding material that do not meet these requirements, shall be approved by SE per

5. Pre-approved rigging frames can be found in Attachment 11 and do not require

SE approval." The rigging frame was not a preapproved design and was not approved by site engineering.

MMTP-102 Section 3.3.1 A. states, in part, that: Scaffolding ladders, and platforms shall be erected to conform with the requirements of this procedure to provide assurance that erected scaffolding, ladders and platforms will not impact the safety-related functions (operability) of plant equipment or systems. Neither the scaffolds or the rigging frame were constructed in accordance with the requirements of MMTP-102, therefore, this challenged the reasonable assurance that the safety related functions of the MCR Chillers were not impacted.

MMTP-102 Section 3.3.1 D.4. states, in part, that: If the required clearance cannot be physically achieved, Site Engineering (SE) evaluation and approval is required for that portion in which the clearance cannot be achieved. The SE evaluation and approval shall be documented on Attachment 5. The clearance requirements were not met for either the scaffolds or the rigging frame, and a site engineering evaluation and approval was not obtained for the non-conformance.

Section 3.3.7 A-C. states, in part, that: "deviations to the seismic requirements of this procedure shall be evaluated by Site Engineering (SE) and approval documented on 5 for SQN and WBN. These evaluations shall be completed in accordance with the site licensing basis. SEs evaluation shall be completed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after the erection process begins." The site engineering evaluations were not completed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the start of erection.

The scaffold adjacent to the B-B MCR Chiller was installed on November 20, 2023 and constructed of a fiberglass ladder tied off to the stainless steel ERCW pipe on bottom.

MMTP-102 Section 3.3.8 states: "Scaffold remaining in the plant for greater than 90 days with the plant at power or for scaffold erected more than 90 days in plant areas under configuration control are designated as a long term scaffold."

MMTP-102 Section 3.3.8 C. states, in part, that: " Any scaffold remaining in the plant for longer than 90 days that do not meet the requirements of Section 3.3.8 are not designated as a long term scaffold. This scaffolding is required to have an evaluation by Site Engineering, a 10CFR50.59 evaluation and a designated removal date." The scaffold did not have a site engineering evaluation, a 10 CFR 50.59 evaluation or a designated removal date.

MMTP-102 Section 3.3.8 E. states: "Long term scaffolds are required to be constructed of tube and clamp material only." This scaffold was constructed of a fiberglass ladder.

MMTP-102 Section 3.4.3 states, in part, that: At WBN, scaffolds may be vertically supported from 4 inch nominal diameter or larger piping in operation without SE evaluation if the following conditions are satisfied. A. Piping system is not stainless steel." The ERCW piping that the scaffold was attached to is stainless steel.

The configuration of the scaffold was not documented in an engineering evaluation, specifically the licensee failed to ensure that the requirements of Section 3.3.8 of MMTP-102 were met and that the deviations from the procedural requirements were evaluated.

This scaffolds and rigging frame were removed from the plant on March 28, 2024.

Corrective Actions: The scaffold pole was removed from the A-A Main Control Room Chiller on February 22, 2024. An engineering inspection of the B-B Main Control Room Chiller Scaffold and Rigging Frame was performed on March 12, 2024.

Corrective Action References: 1902773, 1916312

Performance Assessment:

Performance Deficiency: The licensees failure to implement the requirements of MMTP-102 was a performance deficiency reasonably within their ability to foresee and prevent.

Specifically, by deviating from the requirements of MMTP-102 during and following installation of the scaffolding in the vicinity of the Main Control Room Chillers, Watts Bar challenged their capability to respond to design basis events.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Configuration Control attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the subsequent engineering evaluations did not demonstrate that the MCR Chillers would not be subject to seismic loads greater than those originally analyzed, therefore, this increased the probability of failure during accident mitigation. The inspectors determined that this performance deficiency is similar to example 4.a of IMC 0612 Appendix E.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 3, Barrier Integrity Screening Questions, Section D, Control Room, the screening questions, were all answered NO", therefore, the inspectors determined the finding was of very low safety significance (Green).

Cross-Cutting Aspect: H.11 - Challenge the Unknown: Individuals stop when faced with uncertain conditions. Risks are evaluated and managed before proceeding. Licensee Staff placed protected equipment flagging around the scaffolds in both instances due to the opposite train chiller being tagged out for scheduled maintenance. The failure to question the abnormal scaffolding in the vicinity of the soon to be only operable chiller, did not ensure that station risk was adequately evaluated and managed prior to entering the maintenance windows.

Enforcement:

Violation: 10 CFR 50 Appendix B Criterion V "Instructions, Procedures, and Drawings" states, in part, that: "Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings."

MMTP-102 Rev 022, a quality related procedure, requires in part that scaffold be constructed per the requirements of the procedure or a Site Engineering evaluation be performed.

Contrary to the above, from November 20, 2023, through March 12, 2024, the licensee failed to ensure that scaffolds in the vicinity of the Main Control Room Chillers were constructed in accordance with MMTP-102 requirements.

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

Unresolved Item URI For EDG Governor Failure 71111.15 (Open) URI 05000390,05000391/2024001-08

Description:

CR 1910205 documented that during an initial idle start attempt of the 2A EDG in accordance with 0-SOI-82.03 that the diesel tripped on mechanical overspeed actuation.

This initial run was the first in a sequence of post maintenance tests following a scheduled 2A EDG component outage on February 15, 2024. Investigation identified that the 2301A Governor Card had failed. During testing via Tl-82.05, General Maintenance Practice Guidance for the Emergency Diesel Generator Governor Control System, it was discovered the governor card had no required output at step 6.2 (6). This Governor Card was neither worked nor disturbed during the Diesel Generator component outage.

On March 4, 2024, CR 1914642 was created to track the failure analysis of the failed EDG Governor Card

Planned Closure Actions: Licensee Receipt of Vendor Failure Analysis of 2301A Card tracked under CR 1914642.

Licensee Actions: Replaced Governor Card and PMT was completed on February 16, 2024.

Corrective Action References: 1914642, 1910205

Failure to Identify Condition Adverse to Quality with the Lower Inlet Doors Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [P.2] - 71111.20 NCV 05000391/2023004-01 Evaluation Closed EA-24-032 The inspectors identified a Green finding and an associated NCV of 10 CFR 50 Appendix B Criterion XVI, Corrective Actions, for failure to promptly identify and correct the impact of Unit 2 feedwater leakage on ice condenser lower inlet doors. This condition led to the accumulation of ice on the lower inlet doors challenging their ability to open.

Description:

From January 19, 2023, to November 4, 2023, the licensee was operating under an Adverse Condition Monitoring Plan due to excessive ice buildup on the intermediate deck doors caused by a feedwater leak in lower containment. The licensee recognized that continued operations with the feedwater leak was challenging the aspects of operation of the Unit 2 ice condenser; however, the licensee did not identify any impacts to the opening capability of the lower inlet doors.

On November 5, 2023, licensee staff performed walkdowns of the lower ice condenser and identified adverse conditions (glycol leakage and flow passage ice buildup), but they failed to identify ice accumulation on the lower inlet doors.

On November 5, 2023, after the licensee walkdown, the inspectors performed an independent walkdown and identified excessive ice buildup in the lower ice condenser impacting the ability of at least eight lower inlet doors to open. Specifically, in multiple bays inspectors identified ice accumulation that required excavation to reach the drain lines.

Additionally, in multiple bays inspectors identified ice accumulation that was above the lower edge of the lower inlet doors. Furthermore, inspectors identified clear ice accumulation that proceeded from the lower inlet door seals along the frames in multiple bays.

FSAR Section 6.7.8.1 4. A. Design Criteria - Accident Conditions states, in part, that all doors open to allow venting of energy to the ice condenser for any leak rate which results in a divider deck differential pressure in excess of the ice condenser cold head.

TS SR 3.6.12.3 requires, in part, to verify by visual inspection that the ice condenser inlet door is not impaired by ice, frost, or debris. Watts Bar staff perform this surveillance as part of unit startup activities coming out of a refueling outage.

Inspectors immediately informed the licensee staff of the apparent, non-conforming observations on November 5, 2023. Inspectors held meetings to share observations and documentation with licensee staff in the weeks following the initial identification of the apparent non-conformances.

Corrective Actions: The licensee documented the concern in CR 1893269 on November 18, 2023. and repaired the feedwater check valve. The licensee conducted a more detailed plant analysis as part of a voluntary Phase 2 PRA project. This analysis consisted of a MAAP analysis which modelled the containment structure using 29 nodes modeled vice 6 nodes in the original TMD analysis providing more granularity and better capturing peak pressures in the 24 ice condenser bays. This evaluation established that a minimum of 16 sets of Ice Condenser Lower Doors were required to maintain ice condenser functionality. A set refers to both doors in the same bay.

Corrective Action References: CR 1893269

Performance Assessment:

Performance Deficiency: The licensees failure to identify conditions adverse to quality associated with unexpected ice buildup in the ice condenser was a performance deficiency reasonably within the licensees ability to foresee and correct. Specifically, the licensee failed to identify buildup of ice on the lower inlet doors challenging their safety function.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the SSC and Barrier Performance attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the Blockage of the lower inlet doors challenges the ability of containment to prevent early containment failure.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix H, Containment Integrity SDP. IMC 0609, Appendix H, Table 4.1 lists ice condenser doors as SSCs considered for large early release frequency (LERF Implications)that shall be processed as Type B findings. Table 7.1 screens to Perform Phase 2. Table 7.2 Blockage of more than 15% of the flow passages into or through the ice bed for an exposure period of >3 days results in an initial Risk Significance of Greater than Green and requires Detailed Risk Evaluation.

A Regional Senior Reactor Analyst (SRA) conducted a Phase 3 detailed risk assessment using the guidance in IMC 0609, Appendix H, Containment Integrity Significance Determination Process, IMC 0308, Appendix H, Technical Basis for Operator Requalification Human Performance Significance Determination Process, and NUREG-1765 Basis Document for LERF Significance Determination Process (SDP): Inspection Findings that May Affect LERF.

Exposure Time:

An Adverse Condition Monitoring Plan (ACMP) was put in place on January 19, 2023, based upon observed icing of the intermediate doors. This was known to be from the high humidity environment due to the known steam leak. The ACMP required intermediate deck door testing three times per week to maintain operability. The plant was shutdown on November 4, 2023, and placed in mode 5 on November 5, 2023 (no longer in an applicable mode for containment integrity). Thus, exposure period

(t) is assumed to be January 19 until November 5, 2023, a period of 290 days. Therefore, per Section 2.4 of the RASP Manual Volume 1, for a failure that could have occurred at any time since the component was last operated (e.g.,

time of actual failure cannot be determined due to the nature of the failure mechanism), the exposure time (T) is equal to one-half of the time period since the last successful functional operation of the component (t/2) plus repair time. This exposure time determination approach is appropriate for standby or periodically operated components that fail due to a degradation mechanism that gradually affects the component during the standby time period. The guidance further clarifies, Evidence for considering the failure occurred sometime between last successful operation and discovery time include the following: - Failure mechanism was caused by nominal environmental conditions. Therefore, in this case exposure time (T)would be t/2 with no repair time added since the repairs occurred with the plant in a mode where containment was no longer required. T= 290 days/2 or 145 days.

Per NUREG-1765, Regarding the obstruction of flow due to ice or frost build up or door blockage Westinghouse has provided an evaluation that approximately 15% reduction in flow area can occur and the ice condenser is still considered functional. The 15% limit is based on a short-term-sub-compartment pressure analysis using the TMD code (transient mass distribution), which assumes that flow area blockage will not exceed this value for any of the flow sections in the TMD model. If the integrity of the ice condenser is lost, then it is assumed that containment integrity is also lost.

Per NUREG-1765, for the Lower Inlet doors (2 doors per bay x 24 bays), up to seven doors may be blocked, but not more than one door in any contiguous group of seven doors to keep within the 15% limit. If more than 15% of the area of the flow passage though the ice bed is blocked either due to frost build up or because the doors are unable to perform their function, the integrity of the ice condenser is lost. This is the basis for the criteria in IMC 0609 Appendix H Table 7.2

Per NUREG-1765, unable to perform their function is taken to mean that the doors to the ice chest (especially the lower doors) are not able to open at a differential pressure twice the plant technical specification maximum differential pressure. The basis document for Technical Specification Surveillance Requirement 3.6.12.4 states the design operating pressure is 1.0 lb/ft2 which corresponds to a lifting force of 675 in-lb. Thus, per NUREG-1765 a pressure of 2.0 lb/ft2 or a lifting force of 1350 in-lb would be applied when determining if the door was unable to perform its function. In this case, 3 doors in a contiguous group of 7 were determined to be non-functional based on photographic evidence in ice condenser bays 11 and 12.

NUREG-1765 reference WAT-D-10549, "Maintenance Rule and Ice Condenser Design Questions," attachment to letter from Irons to Maddox, Westinghouse Electric Company, August 27, 1998.also states, There are some sensitivity analyses (circa 1970s) illustrating the effect of the complete failure of a door to open in the break compartment on the pressurization results. Although these were generic in nature and may not exactly apply today, the results did show that the failure of any of the lower inlet doors, especially near TMD break compartment 1 would result in some increase in the peak differential pressure across the shell, the operating deck, the lower crane wall, and the upper crane wall.

Therefore, detailed plant specific analysis would be required to quantify the allowable level of failed doors, the increase in loadings, and the acceptability of the loadings.

The licensee conducted a more detailed plant analysis as part of a voluntary Phase 2 PRA project. This analysis consisted of a MAAP analysis which modelled the containment structure using 29 nodes modeled vice 6 nodes in the original TMD analysis providing more granularity and better capturing peak pressures in the 24 ice condenser bays. This evaluation established that a minimum of 16 sets of Ice Condenser Lower Doors were required to maintain ice condenser functionality. A set refers to both doors in the same bay. The evaluation assumed that no channeling (aka burn though) occurred and the ice mass behind the non-functional doors was conservatively not available. This was supported by Ice Consumption data in the FSAR Chapter 15 accident analysis. The MAAP analysis showed peak event pressure remained within containment design limits both short term and long term for the design basis accidents given 8 sets of non-functional lower doors. The NRC Inspectors, SRA, and Technical Experts reviewed the licensees evaluation and concluded it was best available information and could be used as the Ice Condenser Functional Acceptance Criteria in this case. A SERP was conducted on April.17, 2024 to confirm this conclusion. When this functional acceptance criteria is applied in IMC 0609 Appendix H Table 7.2, this issue screens to very low safety significance (GREEN) because the Ice Condenser remained functional.

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. The licensee failed to perform a thorough evaluation of the as found condition, resulting in a required second evaluation that failed to provide technical evaluation of the as found condition.

Enforcement:

Violation: 10 CFR 50 Appendix B Criterion XVI requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected.

Contrary to the above, from January 19, 2023, to November 5, 2023, TVA at Watts Bar failed to establish measures to assure prompt identification of a conditions adverse to quality affecting the ice condenser lower inlet doors. Specifically, the licensee failed to identify ice accumulation on the lower inlet doors as a result of feedwater leakage in the lower containment. The accumulation of ice on the lower inlet doors challenged the doors ability to perform their safety function as described in the facilitys FSAR.

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

Failure to Implement Requirements of Plant Modification Process Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.13] - 71111.24 NCV 05000390,05000391/2024001-09 Consistent Open/Closed Process The inspectors identified a Green finding and associated NCV of Title 10 CFR Part 50 Appendix B Criterion III, Design Control for failure to implement the plant modification process. Specifically, a Control Room Emergency Ventilation System door dog was modified without an approved Plant Modification.

Description:

On March 05, 2024, during testing on the B Train CREVS a door dog on the filter housing broke during adjustment, this was documented in CR 1914678. The Control Room Emergency Ventilation System, CREVS, is a two train system comprised of fans and filter housings containing HEPA filters, and charcoal adsorbers. The function of the system is to ensure that main control room air is purified during accident scenarios to maintain dose to the operators less than regulatory limits. Access to the filter assemblies is provided through doors on the side of the filter housing. These doors are held shut by latch mechanisms "dogs". The function of the dogs is to retain the door in its position and maintain the seal of the door around the door frame. Under WO 124344997 the licensee replaced the broken dog with a dog that was manufactured on site out of tempered naval brass. The original equipment was manufactured out of cast bronze. This change in material was not evaluated prior to installation.

WO 123768602 was completed, and SRO reviewed on March 05, 2024, and TS LCO 3.7.10 was exited at 16:51.

During review the work order the inspectors identified a change in material and brought this concern to the licensee staff on May 06, 2024. CR 1915205 was initiated on March 06, 2024, to document the inspector questions regarding the acceptability of the material that was used to replace the broken dog.

Further review by the inspectors determined that the change to the CREVS door dog was not in conformance with the requirements of the Nuclear Quality Assurance Plan, specifically, the licensee failed to evaluate the change to the material prior to declaring the B Train CREVS operable. CR 1917809 was initiated on March 17, 2024, to document the inspector identification of the change of material not being evaluated prior to installation. Additionally, this CR documented that: "this did not follow the process of change to an SSC IAW NPG-SPP-09.3 and should be replaced with the original material at the next opportunity." During review of the licensee's material inventory, it was discovered that the appropriate dog assembly was available in the warehouse with surplus stock available.

NPG-SPP-09.3 "Plant Modifications and Engineering Change Control" Section 3.3.3 B.

states, in part, that: "By the NQAP, TVA-NQA-PLN89-A, Design Verification is required for all changes to safety related and augmented quality SSCs that are under Appendix B Criterion III, Design Control."

TVA Nuclear Quality Assurance Plan, TVA-NQA-PLN-89-A, Section 7.2.2 Design Inputs, A.

states: "Design assumptions, design inputs, and deviations from approved design inputs shall be identified, reviewed, approved, and documented prior to declaring the structure, system, or component affected by the design operable."

Section 7.2.6 Design Verification E. states, in part, that: "For operating nuclear units, design verification shall be complete prior to reliance upon the component, system, or structure to perform its function."

Section 7.2.7 A. states: "Design changes, including field changes and modifications, shall be identified. They are subject to design control measures commensurate with or better than those applied to the original design."

Corrective Actions: EWR 124365312 and CR 1923155 were initiated to assess the non-conformance.

Corrective Action References: CR 1923548, CR 1914678, CR 1915205

Performance Assessment:

Performance Deficiency: The licensee's failure to process the material change in accordance with NPG-SPP-09.3 was a performance deficiency reasonably within their ability to foresee and prevent. Specifically, the material change to the B Train CREVS filter housing door dog was not performed in accordance with NPG-SPP-09.3. This unevaluated change challenged the reasonable assurance of operability of the B Train CREVS.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the licensee failed to maintain the CREVS Filter Housing in accordance with the as designed and qualified configuration. This change was not evaluated prior to return to service and after the B Train CREVS was declared Operable. The performance deficiency was more than minor due to the need to create an use-as-is evaluation, to demonstrate that the installed dog was acceptable for use. This condition is similar to Example 5.a of IMC 0612 Appendix E.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The questions in exhibit 3, Barrier Integrity Screening Questions, Section D, Control Room, Auxiliary, Reactor, or Spent Fuel Pool Building, were answered with "NO" which screens to Green.

Cross-Cutting Aspect: H.13 - Consistent Process: Individuals use a consistent, systematic approach to make decisions. Risk insights are incorporated as appropriate. Specifically, the failure to follow the Plant Modification Procedure directly resulted in challenges to the reasonable assurance of the B Train CREVS Unit being able to perform its credited functions.

Enforcement:

Violation: Title 10 CFR 50 Appendix B Criterion III "Design Control" states, in part, that:

"Design changes, including field changes, shall be subject to design control measures commensurate with those applied to the original design and be approved by the organization that performed the original design unless the applicant designates another responsible organization."

NPG-SPP-09.3 Plant Modifications and Engineering Change Control Section 3.3.3 B. states, in part, that: "By the NQAP, TVA-NQA-PLN89-A, Design Verification is required for all changes to safety related and augmented quality SSCs that are under Appendix B Criterion III, Design Control."

TVA Nuclear Quality Assurance Plan, TVA-NQA-PLN-89-A Section 7.2.6 Design Verification E. states, in part, that: "For operating nuclear units, design verification shall be complete prior to reliance upon the component, system, or structure to perform its function."

Section 7.2.7 A. states: "Design changes, including field changes and modifications, shall be identified. They are subject to design control measures commensurate with or better than those applied to the original design."

Contrary to the above since March 5, 2024, the licensee failed to ensure that design changes to the CREVS door dog were subject to the design control measures commensurate with those applied to the original design.

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

EXIT MEETINGS AND DEBRIEFS

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

• On April 19, 2024, the inspectors presented the integrated inspection results to Tony Williams and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.05 Fire Plans DGB-0-72-01 Diesel Generator Building 742.0 ELV. 04

71111.05 Fire Plans PFP NO: DGB-0- Prefire Plan Diesel Generator Building ELV 742.0 04

2-01

71111.05 Fire Plans SER-0-741-01 WBN-PREFIRE-PLAN SERVICE BLDG. 741.0 ELV. 03

71111.12 Work Orders Work Order 123573243 01/09/2024

71111.24 Work Orders Work Orders 123612007 01/01/2024

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