IR 05000327/2024001

Integrated Inspection Report 05000327/2024001 and 05000328/2024001

ML24106A181
Person / Time
Site:	Sequoyah
Issue date:	04/17/2024
From:	Louis Mckown Division Reactor Projects II
To:	Jim Barstow Tennessee Valley Authority
References
IR 2024001
Download: ML24106A181 (12)

Text

SUBJECT:

SEQUOYAH, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000327/2024001 AND 05000328/2024001

Dear Jim Barstow:

On March 31, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Sequoyah, Units 1 and 2. On April 9, 2024, the NRC inspectors discussed the results of this inspection with Tom Marshall, site vice president, and other members of your staff. The results of this inspection are documented in the enclosed report.

No findings or violations of more than minor significance were identified during this inspection.

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. 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: 05000327/2024001 and 05000328/2024001

Licensee: Tennessee Valley Authority

Facility: Sequoyah, Units 1 and 2

Location: Soddy Daisy, TN 37379

Inspection Dates: January 1, 2024 to March 31, 2024

Inspectors: D. Hardage, Senior Resident Inspector A. Price, 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 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

No findings or violations of more than minor significance were identified.

Additional Tracking Items

None.

PLANT STATUS

Unit 1 began the inspection period at rated thermal power (RTP). On March 3, 2024, the unit began end-of-life coast down. On March 22, 2024, the unit was at 85 percent RTP and shutdown for refueling outage 1R26. The unit remained shutdown for refueling the remainder of the inspection period.

Unit 2 operated at or near RTP for the entire inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

71111.01 - Adverse Weather Protection

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

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather due to impending freezing temperatures on January 11, 2024.

71111.04 - Equipment Alignment

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

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

(1) Spare 2-S 125-volt (V) vital battery charger alignment to vital battery board IV during scheduled preventative maintenance on vital battery charger IV on January 24, 2024.

(2) Unit 2 A train component cooling water system (CCS) alignment following restoration of 2A2 CCS heat exchanger from cleaning on March 10, 2024.

(3) Safety injection system alignment for low temperature overpressure protection in Mode 5 with the reactor coolant system (RCS) in a solid water configuration on March 23, 2024.

(4) Unit 1 residual heat removal system (RHR) aligned for RCS cooldown in Mode 6 with RCS level below the flange on March 27, 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) Units 1 and 2 auxiliary building, elevation 653 on January 3, 2024.

(2) Units 1 and 2 auxiliary building, elevation 690 on January 31, 2024.

(3) Units 1 and 2 auxiliary building, elevation 669 on February 29, 2024.

(4) Units 1 and 2 auxiliary building, elevation 749, electrical board, battery, and transformer rooms on March 6, 2024.

(5) Units 1 and 2 auxiliary building, elevation 759 on March 21, 2024.

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

(1) The inspectors evaluated the onsite fire brigade training and performance during an unannounced fire drill on January 31, 2024.

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the unit 1 and unit 2 auxiliary building, elevation 749, electrical board, battery, and transformer rooms on March 4, 2024.

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) 2A1 CCS heat exchanger on February 12, 2024.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)

(1) The inspectors observed and evaluated a simulator training scenario focused on refueling outage RHR operations including a loss of RHR while in mid-loop operations due to loss of offsite power with a diesel generator failure on February 27, 2024.

(2) The inspectors observed and evaluated licensed operator performance in the main control room during shutdown and cooldown for refueling outage 1R26 on March 22, 2024.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (2 Samples)

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

(1) Maintenance rule preventable functional failure of 2-FCO-030-246B, 480V transformer room ventilation supply damper operator due to the connecting rod separating from the damper, cause determination and evaluation (CDE) 3198, on January 25, 2024.

(2) Maintenance rule CDE 3235 for the B electric board room chiller failure to start following maintenance on March 29, 2024.

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 21 thru 28, including protected equipment reviews for scheduled maintenance on 120V vital battery charger IV and 1B emergency diesel generator (EDG).

(2) Week of January 29, including protected equipment review for repairs to the 2A safety injection pump (SIP) and review of the associated risk-informed-completion-time requirements on February 1, 2024.

(3) Unit 1 and 2, week of February 25 thru March 1, including protected equipment review for scheduled maintenance on the unit 1 steam-driven auxiliary feedwater pump, cleaning of the 2A2 CCS heat exchanger and the A main control room chiller.

(4) Unit 1, Yellow shutdown risk week of March 25-29, while RCS level was below the reactor flange level for reactor disassembly, including review of defense-in-depth protected equipment for 1R26.

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)

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

(1) 1A and 2A EDG battery rack each have a tie rod completely corroded through on January 2, 2024.

(2) 2A SIP oil analysis indicates an increase in metals, specifically chromium and nickel on January 30, 2024.

(3) Unit 2 turbine-driven auxiliary feedwater pump had an unknown substance in the catch basin of the outboard pump bearing on February 1, 2024.

(4) Scaffold supported by CCS piping above the 2B centrifugal charging pump on February 29, 2024.

(5) Loss of backup containment penetration conductor overcurrent protective device for reactor coolant pump 1-2 on February 29, 2024.

(6) Pressurizer power operated relief valve 1-PCV-68-340 failed initial close valve stroke time on March 23, 2024.

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) Design equivalent change package SQN-24-001. Change normal configuration of auxiliary feedwater LCVs to open on February 15, 2024.

71111.20 - Refueling and Other Outage Activities

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

(1) (Partial)

The inspectors evaluated unit 1 refueling outage 1R26 activities from March 22 thru March 31, 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) (4 Samples)

(1) WO (work order) 123554426. 1A SIP oil cooler inspection on January 31, 2024.

(2) WO 119348977. Implement ECP 23886 (rev. 1) to replace QA essential raw cooling water pump packing on February 2, 2024.

(3) WO 124228677. Replace 2A SIP pump shaft and bearings on February 4, 2024.

(4) WO 124306595. Replace pressurizer pressure transmitter SQN-2-PT-068-0323 on March 18, 2024.

Surveillance Testing (IP Section 03.01) (3 Samples)

(1) 2-PI-OPS-047-002.0, Steam Inlet Valve Testing on March 6, 2024.

(2) 1-SI-OPS-088-001.0, Phase A Isolation Test on March 24, 2024.

(3) 1-SI-OPS-082-026.B, Loss of Offsite Power with Safety Injection - D/G 1B-B Test on March 26, 2024.

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

(1) 1-SI-SXP-003-202.A, Motor Driven Auxiliary Feedwater Pump 1A-A Comprehensive Performance Test on March 22, 2024.

71114.06 - Drill Evaluation

Required Emergency Preparedness Drill (1 Sample)

(1) Emergency preparedness training drill including a general emergency resulting from a loss of coolant accident with fuel failure and containment failure conducted on February 14,

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, 2023 through December 31, 2023).

(2) Unit 2 (January 1, 2023 through December 31, 2023).

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

(1) Unit 1 (January 1, 2023 through December 31, 2023).

(2) Unit 2 (January 1, 2023 through December 31, 2023).

===71152A - Annual Follow-up Problem Identification and Resolution

Annual Follow-up of Selected Issues (Section 03.03)===

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

(1) Condition report (CR) 1697913. Low margin for motor-driven auxiliary feedwater pump 1B-B.

(2) CR 1916599. Technical Requirement (TR) 7.5.3 assessment on nonfunctional seismic monitors 0-XT-52-75A and 0-XT-52-75B.

INSPECTION RESULTS

No findings were identified.

EXIT MEETINGS AND DEBRIEFS

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

• On April 9, 2024, the inspectors presented the integrated inspection results to Tom Marshall, site vice president, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action CR 1902428 Freeze Protection Issue 0-PI-OPS-000-006.0 01/11/2024

Documents

Procedures 0-PI-OPS-000- Freeze Protection Revision 74

006.0

71111.04 Procedures 0-SO-250-1 125 Volt DC Vital Power System Revision 88

1-SI-OPS-068-Low Temperature Overpressure Protection Revision 13

001.1

2-SO-62-5 Emergency Core Cooling System Revision 70

2-SO-70-1, Component Cooling Water System "A" Train Valve Checklist 10/17/2021

71111.05 Corrective Action CR 1913750 Scaffold in contact with piping for shutdown board room air 02/29/2024

Documents handling units

Resulting from

Inspection

Fire Plans AUX-0-653-00 Fire Protection Pre Fire Plans Auxiliary Building - El. 653 Revision 9

AUX-0-690-01 Fire Protection Pre Fire Plans Auxiliary Building (El. 690 Unit Revision 9

Side)

AUX-0-690-02 Fire Protection Pre Fire Plans Auxiliary Building (El. 690 Unit Revision 9

Side)

AUX-0-749-01 Fire Protection Pre Fire Plans Auxiliary Building (El. 749 Unit Revision 13

Side)

AUX-0-749-02 Fire Protection Pre Fire Plans Auxiliary Building (El. 749 Unit Revision 14

Side)

AUX-0-759-01 Fire Protection Pre-Fire Plans Revision 6

Auxiliary Building (El. 759 Unit 1 Side)

AUX-0-759-02 Fire Protection Pre-Fire Plans Revision 7

Auxiliary Building (El. 759 Unit 2 Side)

PFP NO: FPH Fire Protection Pre-Fire Plans Revision 1

Fire Pump House

71111.06 Calculations MDN-000-000- SQN Probabilistic Risk Assessment - Internal Flooding Revision 6

2010-0203 Analysis

Procedures AOP-M.08 Internal Flooding Revision 8

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.07A Work Orders WO 12379629 2A1 CCS heat exchanger clam and mic inspection 02/20/2024

71111.12 Corrective Action CR 1819324 Operator connecting rod separated from dampers 11/26/2022

Documents CR 1909937 "B" Electric Board Room Chiller failed to startup during PMT 02/14/2024

run

WO 124198051 Remove/Replace B-B EBR Chiller Compressor Motor Starter 02/12/2024

Procedures NPG-SPP-03.4 Maintenance Rule Performance Indicator Monitoring, Revision 5

Trending and Reporting - 10CFR50.65

TI-4 Maintenance Rule Performance Indicator Monitoring Revision 39

Trending, and Reporting - 10CFR50.65

Work Orders WO 124302610 B Electric Board Room Chiller failed to startup during PMT 03/05/2024

71111.13 Corrective Action CR 1906501 NRC identified boric acid build up on 2BB safety injection 01/29/2024

Documents casing flange and vent valve

Resulting from CR 1920063 NRC identified protected equipment barrier missing and 03/27/2024

Inspection scaffold touching flex conduit in 1A RHR pump room

Procedures 0-GO-16 System Operability Checklists Revision 36

71111.15 Corrective Action CR 1900954 2AA SIP oil analysis 01/03/2024

Documents CR 1913939 1B 6.9KV unit board control power auto transferred to 02/29/2024

alternate

CR 1914385 TR 3.7.5 condition report - 1B 6.9KV Unit Board BD control 03/01/2024

power transfer

Corrective Action CR 1900168 Significant Corrosion on EDG battery rack tie rods 12/27/2023

Documents CR 1907411 NRC identified unknown substance U2 TDAFW stuffing box 02/01/2024

Resulting from gland

Inspection CR 1913856 Scaffold attached to safety related piping 02/29/2024

Work Orders WO 124221101 Perform flush and CUNO inspection 01/30/2024

71111.20 Corrective Action CR 1919426 White powder (boric acid or sodium tetraborate) behind the 03/25/2024

Documents base of pressurizer

Resulting from CR 1919430 Leak on component cooling water line to RCP 1-2 thermal 03/25/2024

Inspection barrier

Procedures 0-SI-SXX-068-RCS and Pressurizer Temperature and Pressure Limits Revision 17

27.0

71111.24 Corrective Action CR 1918307 MFP speed probe deviation alarms during AFW 03/20/2024

Documents comprehensive test

CR 1918999 Procedure change request - AFW Pump Comprehensive 03/23/2024

Inspection Type Designation Description or Title Revision or

Procedure Date

Tests

CR 1919433 ERCW pump L-B would not start manually as directed 1-SI- 03/26/2024

OSP-082-026.B

Procedures 2-SI-ICC-068-Channel Calibration of Pressurizer Pressure Channel III, Revision 21

23.3 Rack 9, Loop 2-P-68-323

2-SI-SXP-063-Safety Injection Pump 2A-A Performance Test Revision 29

201.A

MI-6.9 Safety Injection Pump Inspection and Rebuild Revision 23

71151 Corrective Action CR 1851189 Unit 2 SI-137.0 unidentified leakage at Action Level II 04/19/2023

Documents

71152A Corrective Action CR 1697633 1B MDAFW Pump DP below acceptance criteria 05/29/2021

Documents CR 1697806 MDAFW critical spare exhibited marginal performance 05/31/2021

Engineering EWR 21-DEM-MDAFWP pump curve (generic location) Revision 2

Evaluations 003-076

SQN-0-24-017 PRA Evaluation for seismic monitors nonfunctionality 03/12/2024

10