IR 05000327/2023001

Integrated Inspection Report 05000327/2023001 and 05000328/2023001 and Exercise of Enforcement Discretion

ML23121A321
Person / Time
Site:	Sequoyah
Issue date:	05/02/2023
From:	Louis Mckown Division Reactor Projects II
To:	Jim Barstow Tennessee Valley Authority
References
EA-23-042 IR 2023001
Download: ML23121A321 (20)

Text

SUBJECT:

SEQUOYAH, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000327/2023001 AND 05000328/2023001 AND EXERCISE OF ENFORCEMENT DISCRETION

Dear Jim Barstow:

On March 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Sequoyah, Units 1 and 2. On April 25, 2023, the NRC inspectors discussed the results of this inspection with Mr. Tom Marshall and other members of your staff. The results of this inspection are documented in the enclosed report.

One finding of very low safety significance (Green) is documented in this report. This finding did not involve a violation of NRC requirements.

If you disagree with a cross-cutting aspect assignment or a finding not associated with a regulatory requirement 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 Sequoyah, Units 1 and 2.

This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document May 2, 2023 Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Lou J. McKown II, Chief Reactor Projects Branch 5 Division of Reactor Projects Docket Nos. 05000327 and 05000328 License Nos. DPR-77 and DPR-79

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000327 and 05000328

License Numbers: DPR-77 and DPR-79

Report Numbers: 05000327/2023001 and 05000328/2023001

Licensee: Tennessee Valley Authority

Facility: Sequoyah, Units 1 and 2

Location: Soddy Daisy, TN 37379

Inspection Dates: January 01, 2023, to March 31, 2023

Inspectors: B. Bowker, Reactor Inspector D. Hardage, Senior Resident Inspector B. Kellner, Senior Health Physicist M. Magyar, Reactor Inspector A. Nielsen, Senior Health Physicist A. Price, Resident Inspector

Approved By: Lou 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 Sequoyah, Units 1 and 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

Failure of Unit 2 main transformer neutral bus due to incorrect installation of insulators Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.7] - 71152A FIN 05000328/2023001-01 Documentation Open/Closed A self-revealed Green finding was identified when the licensee failed to adequately implement TVA Transmissions Substation and Switchyard Design Standard TE-SE-DES-09.200.4.6,

Electrical Buses and Insulators, to ensure the Unit 2 main transformer neutral bus insulators were installed to accommodate thermal expansion. Specifically, contrary to TE-SE-DES-09.200.4.6, all neutral bus insulator clamps were assembled in the fixed orientation on the Unit 2 main transformer neutral bus insulators during 2A main bank transformer (MBT)replacement. This configuration did not allow for thermal expansion and led to failure of the insulators on the neutral bus which required operators to deenergize the main transformer.

Additional Tracking Items

Type Issue Number Title Report Section Status EDG EA-23-042 Failure to Comply with 10 71124.08 Closed CFR 37 for the Protection of Radioactive Material Contained in Contaminated Steam Generators Stored in a Concrete Mausoleum LER 05000327/2022-002-00 LER 2022-002-00 for 71153 Closed Sequoyah Nuclear Plant,

Unit 1, Turbine Trip Function Inoperable Due to Slow to Close Turbine Throttle Valve

PLANT STATUS

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

Unit 2 began the inspection period at RTP. The unit entered end of life coastdown on February 26, 2023. On March 17, 2023, the unit was at 84 percent RTP and shutdown for refueling outage 2R25. The unit remained shutdown for refueling 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 due to severe thunderstorms and tornado watch on January 12, 2023.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (2 Samples)

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

(1) 1A Emergency Diesel Generator (EDG) while 1B EDG was out of service for planned maintenance on January 25, 2023

(2) Unit 2 residual heat removal system (RHR) aligned for reactor coolant system (RCS)cooldown in Mode 5 on March 18, 2023

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 1 and Unit 2 EDGs on January 5, 2023.

71111.05 - Fire Protection

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

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

(1) Unit 1 and Unit 2 Cable Spreading Room, Control Building Elevation 706 on January 4, 2023

(2) EDG Building Elevation 722 on January 25, 2023

(3) Unit 1 and Unit 2 Auxiliary Building, Elevation 653 on February 12, 2023

(4) Essential Raw Cooling Water Building on March 1, 2023

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the turbine building in preparation for maintenance activities to install isolation valves in the in service raw cooling water main header.

===71111.08P - Inservice Inspection Activities (PWR)

PWR Inservice Inspection Activities Sample - Nondestructive Examination and Welding Activities (IP Section 03.01)===

The inspectors verified that the following nondestructive examination and welding activities were performed appropriately:

(1) Ultrasonic Examination (UT)

RHRF-124, Elbow to Valve, Augmented (observed)

RHRF-109, Elbow to Valve, Augmented (observed)

RHRS-188, Pipe to Elbow, Augmented (observed)

Visual Examination (VT)

Bare metal visual of the Reactor Vessel Closure Head, N-729-6 (observed)

PWR Inservice Inspection Activities Sample - Vessel Upper Head Penetration Inspection

Activities (IP Section 03.02) (1 Sample)

The inspectors verified that the license conducted the following vessel upper head penetration inspections and addressed any identified defects appropriately:

(1) Bare metal visual of the Reactor Vessel Closure Head, N-729-6 (observed)

PWR Inservice Inspection Activities Sample - Boric Acid Corrosion Control Inspection Activities (IP Section 03.03) (1 Sample)

The inspectors verified the licensee is managing the boric acid corrosion control program through a review of the following evaluations:

(1) Boric Acid Walkdown - March 29, 2023 CR1846476 CR1846477 CR1846481 CR1846482 CR1846493

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 inspector observed and evaluated licensed operator performance in the main control room during shutdown and cooldown for U2R25 on March 17, 2023.

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

(1) The inspectors observed and evaluated a simulator training scenario including a loss of all AC power and a steam generator tube rupture on January 18, 2023.

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) Maintenance rule functional failure of the A Main Control Room chiller (CDE 3199) on February 7, 2023.

(2) Maintenance rule functional failure of the Unit 1 Turbine Stop Valve #2 (CDE 3193)on March 8, 2023.

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)

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

(1) Unit 1 and 2, week of January 15 - January 21, 2023, including protection equipment reviews for scheduled maintenance on the 1A EDG, common station service transformer B and C station service air compressor.

(2) Unit 1 and 2, week of January 22 - January 26, 2023, including protection equipment reviews for scheduled maintenance on the 1B EDG and common station service transformer B.

(3) Unit 1 and 2, week of March 12 - March 18, 2023, including protection equipment reviews for emergent inoperability of 1A EDG, 1A motor-driven auxiliary feedwater (MDAFW) pump and 2A MDAFW pump and scheduled maintenance on the Unit 2 turbine-driven auxiliary feedwater pump.

(4) Unit 2, Yellow shutdown risk week of March 19-25, while RCS level was below the reactor flange level for reactor disassembly, including review of defense in depth protected equipment for U2R25.

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

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

(1) Closing of RHR cross-connect valves to facilitate RCS check valve testing in mode 3 on January 9, 2023

(2) 1B-B centrifugal charging pump (CCP) discharge line leaking past 1A-A CCP check valve, 1-62-525 on January 27, 2023

(3) 2-LCV-3-164, Steam Generator 1 auxiliary feedwater level control valve, failed stroke test on March 13, 2023

(4) PK block spare contact point broken on 1A 6.9 shutdown board 1A-A on March 13, 2023

(5) Holes in ice transport return line breach the auxiliary building secondary containment enclosure barrier on March 23, 2023

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)

The inspectors evaluated the following temporary or permanent modifications:

(1) TMOD 2019-082-001-01, Remove 1A-A EDG tandem RVDT exciter assembly, DC signal comparator, and DC power supply while maintaining functionality of 1A-A EDG

71111.20 - Refueling and Other Outage Activities

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

(1) The inspectors evaluated refueling outage 2R25 activities from March 18 - March 31, 2023

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) (3 Samples)

(1) Work order (WO) 122833637, 1A Diesel Generator ambient manual start following preventative maintenance outage on January 19, 2023

(2) WO 122806789, Perform As Found MOV test and PM inspection on 2-MVOP-1-151-S, Turbine Driven AFW pump Trip and Throttle Valve on March 16, 2023

(3) WO 123550931, Verification of no external leakage after cutting, removing blockages and rewelding ice condenser bay 1 to 12 AHU condensate drain line on March 29, 2023

Surveillance Testing (IP Section 03.01) (2 Samples)

(1) Unit 2 Testing and Setting of Main Steam Safety Valves on March 16, 2023

(2) 2-SI-OPS-088-001.0, Phase A Isolation Test on March 19, 2023

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

(1) 2-SI-SXP-074-202.0, RHR Pump 2A-A and 2B-B Comprehensive Performance and Check Valve Test on March 22, 2023

Containment Isolation Valve (CIV) Testing (IP Section 03.01) (1 Sample)

(1) 0-SI-SLT-070-258.1, Containment Isolation Valve Local Leak Rate Test, Component Cooling System to RCP Oil Coolers Inboard (Penetration X-52) on March 30,

71124.01 - Radiological Hazard Assessment and Exposure Controls

Radiological Hazard Assessment (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated how the licensee identifies the magnitude and extent of radiation levels and the concentrations and quantities of radioactive materials and how the licensee assesses radiological hazards.

Instructions to Workers (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated how the licensee instructs workers on plant-related radiological hazards and the radiation protection requirements intended to protect workers from those hazards.

Contamination and Radioactive Material Control (IP Section 03.03) (2 Samples)

The inspectors observed/evaluated the following licensee processes for monitoring and controlling contamination and radioactive material:

(1) Licensee surveys of potentially contaminated material leaving the RCA.

(2) Workers exiting the RCA during the Unit 2 refueling outage.

Radiological Hazards Control and Work Coverage (IP Section 03.04) (3 Samples)

The inspectors evaluated the licensee's control of radiological hazards for the following radiological work:

(1) Unit 2 Transfer Canal diving activities to repair transfer tube valve - ALARA Work Plan 2023-244 [Spent Fuel Pool side]

(2) Inspection & Rebuild of accumulator check valve 2-VLV-063-0634 - ALARA Work Plan 2023-240

(3) Unit 2 Reactor disassembly activities - ALARA Work Plan 2023-211

High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (5 Samples)

The inspectors evaluated licensee controls of the following High Radiation Areas and Very High Radiation Areas:

(1) Unit 2 Keyway access in containment (Grave Danger/LHRA)

(2) Unit 2 Letdown Heat Exchanger Room in containment (LHRA)

(3) Tritiated Drain Tank Room - Aux Building 653' elevation (LHRA)

(4) Spent Resin Tank Room - Aux Building 669' elevation (LHRA)

(5) SFP Underwater Storage Lock Box (LHRA)

Radiation Worker Performance and Radiation Protection Technician Proficiency (IP Section 03.06) (1 Sample)

(1) The inspectors evaluated radiation worker and radiation protection technician performance as it pertains to radiation protection requirements.

71124.08 - Radioactive Solid Waste Processing & Radioactive Material Handling, Storage, &

Transportation

Radioactive Material Storage (IP Section 03.01)

The inspectors evaluated the licensees performance in controlling, labeling and securing the following radioactive materials:

(1) Dry Active Waste (DAW) building storage area

(2) Radioactive material storage area 15

(3) Disused steam generator storage mausoleum

Radioactive Waste System Walkdown (IP Section 03.02) (1 Sample)

The inspectors walked down the following accessible portions of the solid radioactive waste systems and evaluated system configuration and functionality:

(1) Liquid radwaste processing filtration and demineralizer system

Waste Characterization and Classification (IP Section 03.03) (2 Samples)

The inspectors evaluated the following characterization and classification of radioactive waste:

(1) 2022 DAW

(2) Primary resin liner PO699639

Shipment Preparation (IP Section 03.04) (1 Sample)

(1) The inspectors observed the preparation of a radioactive shipment of DAW on March 30, 2023.

Shipping Records (IP Section 03.05) (5 Samples)

The inspectors evaluated the following non-excepted radioactive material shipments through a record review:

(1) Shipping record 21-0401, Type B, Filters

(2) Shipping record 22-0601, Low Specific Activity (LSA), primary resin

(3) Shipping record 22-0702, LSA, radwaste resin

(4) Shipping record 22-1103, Surface Contaminated Object, vendor equipment

(5) Shipping record 22-0301, Type B, primary resin

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10)===

(1) Unit 1 (January 1, 2022 through December 31, 2022)

(2) Unit 2 (January 1, 2022 through December 31, 2022)

BI02: RCS Leak Rate Sample (IP Section 02.11) (2 Samples)

(1) Unit 1 (January 1, 2022 through December 31, 2022)

(2) Unit 2 (January 1, 2022 through December 31, 2022)

OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)

(1) October 1, 2022 through March 31, 2023

PR01: Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual Radiological Effluent Occurrences (RETS/ODCM) Radiological Effluent Occurrences Sample (IP Section 02.16) (1 Sample)

(1) November 19, 2022 through February 28, 2023

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

(1) Unit 2 main transformer neutral bus insulator failure on June 1, 2022

(2) Unit 2 Reactor Coolant Pump 1 has red brown possible boron buildup on five main flange hydranuts on March 21, 2023

71153 - Follow Up of Events and Notices of Enforcement Discretion Event Report (IP section 03.02)

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

(1) LER 50-327/2022-002-00, Turbine Trip Function Inoperable Due to Slow to Close Turbine Throttle Valve (ADAMS accession: ML22349A023) The inspectors determined that it was not reasonable to foresee or correct the cause discussed in the LER therefore no performance deficiency was identified. The inspectors also concluded that no violation of NRC requirements occurred.

INSPECTION RESULTS

Enforcement Enforcement Action EA-23-042: Failure to Comply with 10 CFR 71124.08 Discretion 37 for the Protection of Radioactive Material Contained in Contaminated Steam Generators Stored in a Concrete Mausoleum

Description:

On November 10, 2021, the NRC issued Inspection Report numbers 05000327/2021003 and 05000328/2021003, which documented a violation of 10 CFR Part 37.11 involving disused steam generators (>Category 2 material, exempt waste) stored in large concrete storage modules. The violation met the criteria for Enforcement Discretion as described in Enforcement Guidance Memorandum (EGM) 14-001, "Interim Guidance for Dispositioning 10 CFR Part 37 Violations with Respect to Large Components or Robust Structures Containing Category 1 or Category 2 Quantities of Material at Power Reactor Facilities Licensed Under 10 CFR Parts 50 and 52." The inspectors re-evaluated storage and security of the steam generators and determined that there have been no changes since the last inspection.

Corrective Actions: The licensee has documented the issue in their corrective action program. As specified in EGM 14-001, the application of discretion is authorized until the underlying technical issue is dispositioned through rulemaking or other regulatory action.

Corrective Action References: CR 1707916

Enforcement:

Violation: On November 10, 2021, a violation of 10 CFR Part 37.11 was documented in Inspection Report numbers 05000327/2021003 and 05000328/2021003. During the week of March 27 - 31, 2023, the inspectors determined that the previously identified violation remains.

Basis for Discretion: This violation continues to meet the criteria for Enforcement Discretion as described in EGM 14-001.

Failure of Unit 2 main transformer neutral bus due to incorrect installation of insulators Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.7] - 71152A FIN 05000328/2023001-01 Documentation Open/Closed A self-revealed Green finding was identified when the licensee failed to adequately implement TVA Transmissions Substation and Switchyard Design Standard TE-SE-DES-09.200.4.6, Electrical Buses and Insulators, to ensure the Unit 2 main transformer neutral bus insulators were installed to accommodate thermal expansion. Specifically, contrary to TE-SE-DES-09.200.4.6, all neutral bus insulator clamps were assembled in the fixed orientation on the Unit 2 main transformer neutral bus insulators during 2A main bank transformer (MBT)replacement. This configuration did not allow for thermal expansion and led to failure of the insulators on the neutral bus which required operators to deenergize the main transformer.

Description:

On the afternoon of June 1, 2022, Security personnel notified Shift Operators of a fallen object near the Unit 2 main transformer. Subsequent inspections by Operators and System Engineering identified a partial collapse of the main transformer neutral bus. The bus remained connected to each in-service MBT neutral bushing and was partially suspended by the 2A MBT high-pressure fire protection piping. On June 1, 2022 at 22:52 Unit 2 commenced a downpower to 20 percent RTP and removed the turbine and main transformer from service for repairs.

The neutral bus for the 161 kV single-phase main transformers (phases A, B, C, and spare) is a 6-inch diameter aluminum tubing that runs horizontally for approximately 200 feet and is supported at five locations by supports that are approximately evenly distributed. These supports are ceramic insulators that are attached to a steel structure.

The 2A MBT had been replaced in the fall of 2021 during the Unit 2 refueling outage. The work scope did not include replacement of the existing neutral bus insulator, but the insulator was removed and reinstalled during this activity. Sequoyah drawings 75N230 and 75N232 were used by craft personnel reassembling the neutral bus but did not identify the desired insulator clamp configuration for the neutral bus insulators which would allow for thermal expansion of the neutral bus. After the insulator failure, each neutral bus insulator clamp was found assembled in the fixed orientation. Such a configuration is inconsistent with recommended substation design practices and limits thermal expansion of the conductor. The preferred method of configuring is a fixed center clamp and slipped adjacent clamps which permits thermal expansion of the bus and reduces the overall loading of the insulators.

The most likely cause of the identified neutral bus damage is excessive thermal expansion of the neutral bus from the existing support configuration (i.e., all fixed supports). Because of the fixed supports, the neutral bus thermal expansion is constrained, applying large loads to the supports. Excessive thermal expansions events including fault transients and daily ambient temperature variations will result in cyclic fatigue to the brittle ceramic insulators, initiating cracks leading to eventual failure.

Corrective Actions: The switchyard was evacuated until the main transformer was deenergized. The damaged insulators were replaced and the neutral bus was reinstalled in the correct configuration. Switchyard drawings were updated to include the required configuration for the neutral bus insulators.

Corrective Action References: CR 1780355, 1781005, 1780826

Performance Assessment:

Performance Deficiency: Failure of the licensee to adequately implement TVA Transmissions Substation and Switchyard Design Standard TE-SE-DES-09.200.4.6, Electrical Buses and Insulators, to ensure the Unit 2 main transformer neutral bus insulator configuration was installed to accommodate thermal expansion of insulators was a performance deficiency. Specifically, contrary to TE-SE-DES-09.200.4.6, all neutral bus insulator clamps were assembled in the fixed orientation on the Unit 2 main transformer neutral bus insulators during 2A main bank transformer (MBT) replacement.

This configuration did not allow for thermal expansion and lead to failure of the insulators.

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, failure of the neutral bus could lead to failure of the main transformer and reactor trip in the event of a grid disturbance and did require an emergent downpower from rated thermal power to take the transformer offline for immediate corrective maintenance.

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 determined the finding was of very low safety significance (Green) using Appendix A, Exhibit 1, Transient Initiators, because the finding did not result in an actual reactor trip and a loss of mitigation equipment relied upon to transition the plant to a stable shutdown condition.

Cross-Cutting Aspect: H.7 - Documentation: The organization creates and maintains complete, accurate and up-to-date documentation. The inspectors determined that the finding had a cross-cutting aspect of Documentation within the cross-cutting area of Human Performance because TVA did not create and maintain complete, accurate, and up-to-date documentation. Specifically, the SQN design drawings did not identify clamp configuration for the neutral bus insulators.

Enforcement:

Inspectors did not identify a violation of regulatory requirements associated with this finding.

EXIT MEETINGS AND DEBRIEFS

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

On April 25, 2023, the inspectors presented the integrated inspection results to Tom Marshall and other members of the licensee staff.

On March 30, 2023, the inspectors presented the ISI Exit Meeting inspection results to SQN Site Vice President - Tom Marshall and other members of the licensee staff.

On March 30, 2023, the inspectors presented the Baseline Radiation Safety Inspection Exit Meeting inspection results to Tom Marshall, Site VP and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Procedures AOP-N.02 Tornado Watch/Warning Revision 45

71111.04 Corrective Action CR 1831518 1-VLV-67-515A, 1A DG ERCW Outlet, found unsealed 01/25/2023

Documents

Resulting from

Inspection

Procedures 0-SO-82-1 Diesel Generator 1A-A Revision 65

71111.05 Corrective Action CR 1827472 Cable Spreading Room Sprinkler Interference 01/05/2023

Documents

Resulting from

Inspection

Fire Plans AUX-0-653-00 Pre-Fire Plan Auxiliary Building Elevation 653 Revision 9

CON-0-706-00 Pre-Fire Plan Control Building Elevation 706 Revision 8

71111.06 Procedures AOP-M.05 Loss of Raw Cooling Water Revision 11

AOP-M.08 Internal Flooding Revision 8

EA-32-2 Establishing Control and Service Air Revision 5

71111.11Q Miscellaneous Simulator SGTR with loss of Station Power Revision 0

Exercise Guide

(SEG)

OPL273S2313

71111.12 Corrective Action CR 1811241 Turbine Stop Valve #2 failed to indicate closed on 1-XX-55-10/22/2022

Documents 6A and locally

CR 1819566 'A' MCR chiller tripped while shutting panel door 11/28/2022

Miscellaneous Cause Maintenance rule functional failure of the Unit 1 Turbine Stop 10/22/2022

Determination Valve #2

Evaluation (CDE)

3193

Cause Maintenance rule functional failure of the A MCR chiller 11/28/2022

Determination

Evaluation (CDE)

3199

71111.13 Procedures 0-GO-16 System Operability Checklists Revision 33

1-PI-OPS-000- Attachment 2 - SQN Defense-in-Depth Assessment Revision 43

Inspection Type Designation Description or Title Revision or

Procedure Date

20.2

NPG-SPP-07-Shutdown Risk Manage Revision 16

2.11

71111.15 Corrective Action CR 1820231 Questionable use of Tech Spec note 11/30/2022

Documents CR 1832017 1B charging pump balance drum flow increase 01/27/2023

CR 1841785 PK block spare contact point broken on 1A 6.9 SDBD 1A-A 03/13/2023

Panel 7

CR 1841940 2-LCV-3-164 failed the valve stroke, the stroke was unusual 03/13/2023

and erratic

CR 1842258 Possible ABSCE Breach Upstream of 0-FLT-61-2123 03/14/2023

CR 1843752 Holes in Ice Transport return line 03/23/2023

Engineering EWR 23-SBE-Ice Return Air Line ABSCE Boundary Evaluation (Unit 2) 03/23/2023

Evaluations 061-035

EWR# 23-DEC-Civil Design to provide seismic functionality recommendation 03/13/2023

2-029 for SQN-1-PK-202-CM7/1-A (GE TEST BLOCKS TYPE

PK2) with broken contactor

Operability CR 1832025 1B-B CCP discharge line is leaking past the 1A-A CCP 01/27/2023

Evaluations check valve, 1-62-525

Procedures 1-SI-SXP-062-Centrifugal Charging Pump 1B-B Performance Test Revision 29

201.B

2-SI-SXV-000- Full Stroking of Category A and B Valves During Operation Revision 22

201.0

71111.20 Corrective Action CR 1844444 Unit 2 Fuel Transfer Tube Wafer Valve appears to be unable 03/22/2023

Documents to full close

Corrective Action CR 1843392 Dry boric acid identified on 2-VLV-68-580, Loop 3 Letdown 03/18/2023

Documents Isolation

Resulting from CR 1843394 Dry boric acid identified on 2-VLV-68-431A, Root valve to 03/18/2023

Inspection FT-68-71A

CR 1843395 Dry boric acid identified on 2-VLV-68-432A, Root valve to 03/18/2023

FT-68-71B

CR 1843396 Dry boric acid identified on 2-VLV-68-433A, Root valve to 03/18/2023

FT-68-71D

CR 1843397 Dry boric acid identified on 2-VLV-68-541, Loop 4 H1 03/18/2023

Isolation

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.24 Procedures 0-SI-SLT-070- Containment Isolation Valve Local Leak Rate Test Revision 19

258.1 Component Cooling

1-SI-OPS-082-Electrical Power System Diesel Generator 1A-A Revision 71

007.A

2-SI-SXP-003-Turbine Driven Auxiliary Feedwater Pump 2A-S Revision 24

2.S Comprehensive Performance Test

71124.01 ALARA Plans 2023-211 U2R25 Rx Disassembly and Reassembly Revision 0

23-244 U2R25 Transfer Canal & Equipment Pit Diving 03/23/2023

Corrective Action Condition Reports (CRs) 1813282, 1813391, 1815914, Various

Documents 1816036, 1816606, 1818135, 1828128, 1831347, and

1846349

Corrective Action 1845870 Scaffold in on 690' elevation in Aux Bldg did not have an RP 03/28/2023

Documents survey tag

Resulting from

Inspection

Miscellaneous Electronic Dosimeter dose and dose rate alarm logs from Various

November 2022 through March 30 2023

Personnel Contamination Event Log 11/1/20222 through Various

3/28/2023

Sequoyah Nuclear Plant - U1R25 Outage ALARA Report 03/08/2023

TEDE-2023-006 Remove/install blind flange and vortex suppressors - RWP 02/16/2023

240023 [Respirators required]

TEDE-2023-007 Cavity seal ring removal and stud hole cleaning - RWP 02/16/2023

240002 [No respirator]

TEDE-2023-008 Rx Head O-Ring Removal, RWP 23240022 [Respirator 02/16/2023

required]

Procedures 0-TI-NUC-000- Storing Material in Spent Fuel Pool or New Fuel Vault [SFP Revision 40

2.0 non-fuel item(s) inventory dated 11/16/2022]

NISP-RP-003 Radiological Air Sampling Revision 1

NPG-SPP-05.18 Radiation Work Permits Revision 9

RCDP-21 Radiological Air Sampling Revision 0

RCI-01 Radiation Protection Program Revision 90

Radiation SQN-M-Unit 2 Aux Building Upender Underwater Survey 03/22/2023

Surveys 20230322-17

Inspection Type Designation Description or Title Revision or

Procedure Date

SQN-M-Unit 2 Aux Building Upender Underwater Survey 03/23/2023

230323-16

SQN-M-Diver survey - repairs on wafer valve 03/24/2023

230324-11

SQN-M-EPRI Survey [post crud burst shutdown source term 03/25/2023

230325-3 trending]

SQN-M-2-VLV-063-0634 Breach 03/27/2023

230327-19

Radiation Work 23210021 U2R25-U-2 Aux Bldg & Annulus Revision 0

Permits (RWPs) 23220002 U2R25 - U-2 Lower Ctmt - High Radiation Area Revision 0

240012 U2R25 - U-2 Upper Ctmnt [NO respirators allowed] Revision 0

240022 U2R25 - U-2 Upper Ctmnt [respirator required] Revision 0

240065 734' SFP Area - Diving activities in the Spent Fuel Pool to 03/22/2023

repair U2 fuel transfer system [transfer tube wafer valve]

Self-Assessments 1724382 Radiological Hazard Assessment and Exposure Control Self 05/16/2022

Assessment

24397 Occupational ALARA Planning and Controls 1/12/2023

71124.08 Corrective Action CR 1707916

Documents CR 1764606

Procedures NPG-SPP-05.6.1 Radiation Protection Implementation of 10CFR37 Category Revision 3

and Category 2 Quantities of Radioactive Material

NPG-SPP-05.9.1 Radioactive Material/Waste Shipments Revision 10

RHSI-13 Administration and Control of Onsite Storage of Low Level Revision 4

Radioactive Waste

Self-Assessments CR 1684128 Radioactive Solid Waste Processing and Radioactive 08/21/21

Material Handling, Storage, and Transportation

CR 1752444 Part 37 Self-Assessment 03/21/2022

71151 Miscellaneous Electronic Dosimeter Dose and Dose Rate Alarm logs Various

(11/1/2022 through 3/30/2023

71152A Corrective Action CR 1780355 Fallen Unit 2 Generator Neutral Bus 06/01/2023

Documents CR 1781005 Unit 2 neutral bus configuration 06/04/2023

CR 1843684 Ice condenser bays 1 to 12 AHU condensate drain line 03/20/2022

clogged

CR 1843794 Remove pool of water from RCP platform 2-4 03/20/2023

Inspection Type Designation Description or Title Revision or

Procedure Date

71153 Corrective Action CR 1811241 Turbine Stop Valve #2 failed to close 10/22/2022

Documents

Operability CA 1811241-001 Perform Past Operability Evaluation on TV-2 10/25/2022

Evaluations

17