IR 05000327/2022002

Integrated Inspection Report 05000327 2022002 and 05000328 2022002

ML22209A243
Person / Time
Site:	Sequoyah
Issue date:	08/01/2022
From:	Louis Mckown Division Reactor Projects II
To:	Jim Barstow Tennessee Valley Authority
References
IR 2022002
Download: ML22209A243 (13)

Text

August 1, 2022

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000327/2022002 AND 05000328/2022002

Dear Mr. Barstow:

On June 30, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Sequoyah Nuclear Plant, Units 1 and 2. On July 19, 2022, 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.

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, Signed by McKown, Louis on 08/01/22 Louis J. McKown, 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: 05000327/2022002 and 05000328/2022002 Enterprise Identifier: I-2022-002-0027 Licensee: Tennessee Valley Authority Facility: Sequoyah Nuclear Plant, Units 1 and 2 Location: Soddy Daisy, TN 37379 Inspection Dates: April 01, 2022 to June 30, 2022 Inspectors: N. Childs, Senior Project Engineer D. Hardage, Senior Resident Inspector Approved By: Louis J. McKown, 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 Nuclear Plant, Units 1 and 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

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) and remained at or near RTP for the entire inspection period.

Unit 2 began the inspection period at RTP. On June 1, 2022, the unit reduced power to 20 percent RTP and removed the turbine from service to perform repairs on the main transformer neutral bus. On June 9, 2022, the turbine was returned to service and the unit was returned to RTP on June 10, 2022. The unit remained at or near RTP for the remainder of the inspection period.

INSPECTION SCOPES

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

71111.01 - Adverse Weather Protection

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

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal summer temperatures including review the material condition of the plants offsite AC power systems and onsite alternate AC power systems, including the switchyard and transformers on May 11, 2022.

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) Vital Instrument Board 2-I with vital invertor 2-I out of service for functional testing on April 5, 2022

(2) Unit 1 auxiliary feedwater (AFW) system following testing of 1A AFW pump testing on April 8, 2021

(3) Unit 2 A train component cooling water (CCS) after restoration from 2A2 CCS heat exchanger cleaning on April 28, 2022

(4) Unit 1 and 2 offsite power while the Unit 2 Unit Station Service Transformers were out of service for corrective maintenance on the main transformer neutral bus on June 8, 2022

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) Unit 1 and Unit 2 Auxiliary Building, Elevation 690 on April 20, 2022

(2) Unit 1 and Unit 2 Auxiliary Building, Elevation 714 on April 27, 2022

(3) Unit 1 and Unit 2 Auxiliary Building, Elevation 653 on May 18, 2022

(4) Unit 1 and Unit 2 Auxiliary Instruments Rooms, Control Building, Elevation 685 on June 2, 2022

(5) Unit 1 and Unit 2, Control Building, Elevation 669 on June 12, 2022

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 at the Unit 1 lube oil storage tank in the Turbine Building on April 13, 2022.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (2 Samples)

(1) The inspectors observed and evaluated licensed operator performance in the main control room during Unit 2 main generator NERC reactive load testing on April 16, 2022.

(2) The inspectors observed and evaluated licensed operator performance in the main control room during an emergent Unit 2 downpower to take the main transformer offline following neutral bus disconnection on June 1, 2022.

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

(1) The inspectors observed and evaluated a simulator examination scenario including a large break loss of coolant accident, loss of a safety related 6.9Kv bus and failure of phase B containment isolation valves to automatically close on June 6, 2022.

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 Unit Station Service Transformer 1B on-load tap changer (CDE 3157) to automatically lower tap positions when demanded on August 5, 2021

Aging Management (IP Section 03.03) (2 Samples)

The inspectors evaluated the effectiveness of the aging management program for the following SSCs that did not meet their inspection or test acceptance criteria:

(1) 18-inch essential raw cooling water (ERCW) piping downstream of containment spray (CS) heat exchanger throttle valve 2-VLV-067-0537A (CR 1668098)

(2) Auxiliary building general ventilation system air handling unit 1-AHU-313-642 fan housing corrosion (CR 1717877)

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) Unit 1 and 2, week of April 17-23, 2022, including protection equipment reviews for scheduled maintenance on the 2A2 component cooling water heat exchanger, and emergent failure of Unit 2 Steam Generator 3 Auxiliary Feedwater Level Controller.

(2) Unit 1 and 2, week of April 24-30, 2022, including protection equipment reviews for scheduled maintenance on the 0B2 component cooling water heat exchanger, and the 2B centrifugal charging pump.

(3) Unit 1 and 2, week of May 8-14, 2022, including planned maintenance on B station air compressor, emergent maintenance on 2B generator bus duct cooling fan including protection equipment reviews, and a conservative operations alert.

(4) Unit 1 and 2, week of May 29-June 4, 2022, including planned maintenance on C and D common station service transformers, and emergent maintenance on the Unit 2 main transformer neutral bus which required removing unit 2 main turbine from service.

(5) Unit 1 and 2, week of June 5-June 11, 2022, including planned maintenance on C common station service transformer, and emergent repair of the Unit 2 main transformer including startup of the Unit 2 main turbine and return to RTP.

71111.15 - Operability Determinations and Functionality Assessments

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

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

(1) Unit 2 unsealed floor drain in upper containment on April 22, 2022

(2) Immediate Determination of Operability for low ERCW flow to the 1A CS heat exchanger on May 24, 2022

(3) Prompt Determination of Operability for multiple ERCW leaks on CCS/AFW Pump Area Cooler A-A on June 5, 2022

(4) Past Operability Evaluation for gas discharge from 1B residual heat removal suction piping on June 9, 2022

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) ECP 23874 Fuel Transfer System Upgrades

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (3 Samples)

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

(1) Work Order (WO) 122262217, Perform a clam and mic inspection on 2A2 CCS Heat Exchanger, on April 22, 2022

(2) WO 122920826, Replace 2B Isophase bus duct cooling fan motor, on May 15, 2022

(3) WO 122973254, CCS and AFW Pump Cooler A-A - Replace Cooler Coil, on June 6, 2022

71111.22 - Surveillance Testing

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

Surveillance Tests (other) (IP Section 03.01) (3 Samples)

(1) 1-SI-SXP-003-201.A, Motor Driven Auxiliary Feedwater Pump 1A-A Performance Test, on April 6, 2022

(2) 2-PI-OPS-047-002.0, Steam Inlet Valve Testing, on April 28, 2022

(3) 1-PI-OPS-047-723.0, Unit 1 Turbine Trip Block Solenoid Valve Test, on May 4, 2022

FLEX Testing (IP Section 03.02) (1 Sample)

(1) 0-PI-SFT-360-001.0, Flex Pumps Operating Instructions for Maintenance Activities, on June 15, 2022

71114.06 - Drill Evaluation

Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) Emergency preparedness training drill involving an extended loss of all AC power resulting in a general emergency conducted on April 20,

OTHER ACTIVITIES - BASELINE

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

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

(1) Unit 1 (April 2021 through March 2022)

(2) Unit 2 (April 2021 through March 2022)

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

(1) Unit 1 (April 2021 through March 2022)

(2) Unit 2 (April 2021 through March 2022)

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

(1) Unit 1 (April 2021 through March 2022)

(2) Unit 2 (April 2021 through March 2022)

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) CR 1727625 Resolution of fuel transfer system exceeding overload setpoint needed

(2) CR 1748187 PRT venting is excessive.

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

(1) The inspectors reviewed the licensees corrective action program for potential adverse trends with the long-term installation of scaffolding that might be indicative of a more significant safety issue.

71153 - Follow Up of Events and Notices of Enforcement Discretion Event Followup (IP Section 03.01)

(1) The inspectors evaluated the circumstances surrounding a notice of unusual event (NOUE) due to unexpected seismic monitoring alarms and the licensees response on

===April 29, 2022.

Personnel Performance (IP Section 03.03) (1 Sample)===

(1) The inspectors evaluated licensee performance in response to Unit 2 failure of the Main Transformer and associated downpower on June 2,

INSPECTION RESULTS

No findings were identified.

EXIT MEETINGS AND DEBRIEFS

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

On July 19, 2022, the inspectors presented the integrated inspection results to Mr. Tom Marshall and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action CR 1744025 MODs in the 161KV Switchyard in a degraded state, leading 12/24/2021

Documents to operator burdens and safety issues

CR 1775628 Perform overhaul of 2B Gen Bus Cooling Fan 05/11/2022

Corrective Action CR 1775623 Temporary Equipment near B/U Security D/G 05/11/2022

Documents

Resulting from

Inspection

71111.04 Procedures 0-SI-OPS-082- AC Electrical Power Source Operability Verification Revision 45

007.W

0-SO-250-2 120 Volt AC Vital Instrument Power System Revision 75

1-SO-3-2 Auxiliary Feedwater System Revision 62

2-SO-70-1 Component Cooling Water System "A" Train Power Revision 10

Checklist 2-70-1.02

2-SO-70-1 Component Cooling Water System "A" Train Valve Checklist Revision 19

2-70-1.03

71111.05 Corrective Action CR 1772110 Several items left in overhead above CCS mezzanine-AB 04/26/2022

Documents 690

Resulting from

Inspection

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

AUX-0-690-01 Pre-Fire Plan Auxiliary Building - El. 690 (Unit 1 Side) Revision 9

AUX-0-690-2 Pre-Fire Plan Auxiliary Building El. 690 (Unit 2 side) Revision 9

AUX-0-714-01 Pre-Fire Plan Auxiliary Building - El. 714 (Col. A1-15, Q-U) Revision 11

AUX-0-714-02 Pre-Fire Plan Auxiliary Building - El. 714 (Col. U-X and U1 & Revision 9

U2 Additional Equip. Builds.)

71111.11Q Miscellaneous SEG# Cycle 22-4 Simulator Exam 1 Revision )

OPL273E2241

Procedures 2-PI-ENG-SERC SERC Verification and Data Reporting of the SQN U2 Main Revision 4

Generator Real and Reactive Power Capability

71111.12 Corrective Action CR 1712648 USST 1B tap changer not tapping 08/06/2022

Documents CR 1720709 Aging Management Program Evaluation Needed for 1-AHU- 09/13/2021

313-642 Fan Housing Corrosion

Inspection Type Designation Description or Title Revision or

Procedure Date

Procedures 0-TPP-DXX-000- License Renewal Aging Management Program Basis Revision 2

100.14 Document Internal Surfaces in Miscellaneous Piping and

Ducting Components Program

0-TPP-DXX-000- License Renewal Aging Management Program Basis Revision 0

100.38 Document Service Water Integrity Program

NEDP-21 License Renewal Program Revision 10

NEDP-21.0.2 License Renewal Activities Prior to Period of Extended Revision 1

Operation

TI-4 Maintenance Rule Performance Indicator Monitoring, Revision 38

Trending, and Reporting - 10CFR50.65

Work Orders WO 121910540 18-inch ERCW Piping Downstream of 2-VLV-67-537A Revision 0

Proactive Mitigation

71111.13 Corrective Action CR 1775437 DFR work and COA 05/11/2022

Documents CR 1775447 2B bus duct cooling fan high vibration and noise 05/11/2022

Procedures 0-GO-16 System Operability Checklists Revision 32

0-SI-OPS-082- AC Electrical Power Source Operability Verification Revision 45

007.W

NPG-SPP-07.3.4 Protected Equipment Revision 12

71111.15 Calculations 30-D053-EPM- Determination of Required ERCW and Air Flow Rates to Revision 10

BVC-052788 ESF Room Coolers

Corrective Action CR 1778610 Low ERCW flow for the 1A containment spray heat 05/24/2022

Documents exchanger

CR 1778964 OPDP-8 IDO not performed correctly 05/25/2022

Miscellaneous ACMP 22-018 Adverse condition monitoring plan (ACMP) for 1A 06/02/2022

containment spray heat exchanger ERCW flow

EWR 22-DEM- Information to support IDO for CR 1778610 05/25/2022

067-061

SO-22-018 Sequoyah operations department standing order for 1A 06/02/2022

containment spray heat exchanger

SQN Design Environmental Design Revision 30

Criteria SQN-DC-

V-21.0

Operability CAR 1762356- Past Operability Evaluation Documentation for CR 1762356 04/02/2022

Evaluations 001

Inspection Type Designation Description or Title Revision or

Procedure Date

CR 1780764 PDO for A-A CCS and AFW pump area cooler isolated for 07/05/2022

ERCW leakage

Procedures 0-SO-30-10 Auxiliary Building Ventilation System Revision 72

71111.19 Procedures 0-MI-MRR-070- Component Cooling System Heat Exchanger Maintenance Revision 16

611.0

0-PI-SFT-067- ERCW Train A Flow Monitoring Revision 6

001.A

0-SI-SXI-000- ASME Section XI Inservice Pressure Test Revision 25

201.0

71114.06 Corrective Action CR 1772024 Simulator programing, RCS model boundary flow area for 04/26/2022

Documents CVCS set to 0.0

Resulting from

Inspection

71152A Corrective Action CR 1773425 On 4/27, PORV tailpipe temperature high alarm received 05/03/2022

Documents CR 1774563 PORV tailpipe temperature began to rise from 110deg 05/07/2022

CR 1777618 Tracking CR for ACMP U1 PORV tailpipe temperature 05/19/2022

71152S Corrective Action CR 1758645 NRC-identified unsatisfactory housekeeping in Unit 1 el. 690 03/01/2022

Documents Pipe Chase

CR 1758645 NRC identified unsatisfactory housekeeping in Unit 2 el 690 03/04/2022

and 669 pipe chase

CR 1768207 Unlabeled Scaffolding in 669 pen room 04/07/2022

CR 1777740 Housekeeping, Scaffolding Removal, U-2 Aux Instrument 05/20/2022

Room

Corrective Action CR 1768277 Deficiencies identified with the Scaffold Program at SQN 04/08/2022

Documents

Resulting from

Inspection

Procedures MMTP-102 Erection of Scaffolds/Temporary Work Platforms and Revision 21

Ladders

11