IR 05000327/2023001
| 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:
Report Numbers:
05000327/2023001 and 05000328/2023001
Enterprise Identifier:
I-2023-001-0042
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
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 Aspect Report Section Initiating Events Green FIN 05000328/2023001-01 Open/Closed
[H.7] -
Documentation 71152A 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 CFR 37 for the Protection of Radioactive Material Contained in Contaminated Steam Generators Stored in a Concrete Mausoleum 71124.08 Closed LER 05000327/2022-002-00 LER 2022-002-00 for Sequoyah Nuclear Plant,
Unit 1, Turbine Trip Function Inoperable Due to Slow to Close Turbine Throttle Valve 71153 Closed
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.
REACTOR SAFETY
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,
RADIATION SAFETY
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)
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 Discretion Enforcement Action EA-23-042: Failure to Comply with 10 CFR 37 for the Protection of Radioactive Material Contained in Contaminated Steam Generators Stored in a Concrete Mausoleum 71124.08
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 Aspect Report Section Initiating Events Green FIN 05000328/2023001-01 Open/Closed
[H.7] -
Documentation 71152A 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
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
Tornado Watch/Warning
Revision 45
Corrective Action
Documents
Resulting from
Inspection
CR 1831518
1-VLV-67-515A, 1A DG ERCW Outlet, found unsealed
01/25/2023
Procedures
0-SO-82-1
Diesel Generator 1A-A
Revision 65
Corrective Action
Documents
Resulting from
Inspection
CR 1827472
Cable Spreading Room Sprinkler Interference
01/05/2023
AUX-0-653-00
Pre-Fire Plan Auxiliary Building Elevation 653
Revision 9
Fire Plans
CON-0-706-00
Pre-Fire Plan Control Building Elevation 706
Revision 8
Loss of Raw Cooling Water
Revision 11
Revision 8
Procedures
EA-32-2
Establishing Control and Service Air
Revision 5
Miscellaneous
Simulator
Exercise Guide
(SEG)
OPL273S2313
SGTR with loss of Station Power
Revision 0
CR 1811241
Turbine Stop Valve #2 failed to indicate closed on 1-XX-55-
6A and locally
10/22/2022
Corrective Action
Documents
CR 1819566
'A' MCR chiller tripped while shutting panel door
11/28/2022
Cause
Determination
Evaluation (CDE)
3193
Maintenance rule functional failure of the Unit 1 Turbine Stop
Valve #2
10/22/2022
Miscellaneous
Cause
Determination
Evaluation (CDE)
3199
Maintenance rule functional failure of the A MCR chiller
11/28/2022
0-GO-16
System Operability Checklists
Revision 33
Procedures
1-PI-OPS-000-
- SQN Defense-in-Depth Assessment
Revision 43
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
20.2
NPG-SPP-07-
2.11
Shutdown Risk Manage
Revision 16
CR 1820231
Questionable use of Tech Spec note
11/30/2022
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
Panel 7
03/13/2023
CR 1841940
2-LCV-3-164 failed the valve stroke, the stroke was unusual
and erratic
03/13/2023
CR 1842258
Possible ABSCE Breach Upstream of 0-FLT-61-2123
03/14/2023
Corrective Action
Documents
CR 1843752
Holes in Ice Transport return line
03/23/2023
EWR 23-SBE-
061-035
Ice Return Air Line ABSCE Boundary Evaluation (Unit 2)
03/23/2023
Engineering
Evaluations
EWR# 23-DEC-
2-029
Civil Design to provide seismic functionality recommendation
for SQN-1-PK-202-CM7/1-A (GE TEST BLOCKS TYPE
PK2) with broken contactor
03/13/2023
Operability
Evaluations
CR 1832025
1B-B CCP discharge line is leaking past the 1A-A CCP
check valve, 1-62-525
01/27/2023
1-SI-SXP-062-
201.B
Centrifugal Charging Pump 1B-B Performance Test
Revision 29
Procedures
2-SI-SXV-000-
201.0
Full Stroking of Category A and B Valves During Operation
Revision 22
Corrective Action
Documents
CR 1844444
Unit 2 Fuel Transfer Tube Wafer Valve appears to be unable
to full close
03/22/2023
CR 1843392
Dry boric acid identified on 2-VLV-68-580, Loop 3 Letdown
Isolation
03/18/2023
CR 1843394
Dry boric acid identified on 2-VLV-68-431A, Root valve to
FT-68-71A
03/18/2023
CR 1843395
Dry boric acid identified on 2-VLV-68-432A, Root valve to
FT-68-71B
03/18/2023
CR 1843396
Dry boric acid identified on 2-VLV-68-433A, Root valve to
FT-68-71D
03/18/2023
Corrective Action
Documents
Resulting from
Inspection
CR 1843397
Dry boric acid identified on 2-VLV-68-541, Loop 4 H1
Isolation
03/18/2023
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
0-SI-SLT-070-
258.1
Containment Isolation Valve Local Leak Rate Test
Component Cooling
Revision 19
1-SI-OPS-082-
007.A
Electrical Power System Diesel Generator 1A-A
Revision 71
Procedures
2-SI-SXP-003-
2.S
Turbine Driven Auxiliary Feedwater Pump 2A-S
Comprehensive Performance Test
Revision 24
23-211
U2R25 Rx Disassembly and Reassembly
Revision 0
U2R25 Transfer Canal & Equipment Pit Diving
03/23/2023
Corrective Action
Documents
Condition Reports (CRs) 1813282, 1813391, 1815914,
1816036, 1816606, 1818135, 1828128, 1831347, and
1846349
Various
Corrective Action
Documents
Resulting from
Inspection
1845870
Scaffold in on 690' elevation in Aux Bldg did not have an RP
survey tag
03/28/2023
Electronic Dosimeter dose and dose rate alarm logs from
November 2022 through March 30 2023
Various
Personnel Contamination Event Log 11/1/20222 through
3/28/2023
Various
Sequoyah Nuclear Plant - U1R25 Outage ALARA Report
03/08/2023
TEDE-2023-006
Remove/install blind flange and vortex suppressors - RWP
240023 [Respirators required]
2/16/2023
TEDE-2023-007
Cavity seal ring removal and stud hole cleaning - RWP
240002 [No respirator]
2/16/2023
Miscellaneous
TEDE-2023-008
Rx Head O-Ring Removal, RWP 23240022 [Respirator
required]
2/16/2023
0-TI-NUC-000-
2.0
Storing Material in Spent Fuel Pool or New Fuel Vault [SFP
non-fuel item(s) inventory dated 11/16/2022]
Revision 40
NISP-RP-003
Radiological Air Sampling
Revision 1
NPG-SPP-05.18
Radiation Work Permits
Revision 9
RCDP-21
Radiological Air Sampling
Revision 0
Procedures
RCI-01
Radiation Protection Program
Revision 90
Radiation
Surveys
SQN-M-
230322-17
Unit 2 Aux Building Upender Underwater Survey
03/22/2023
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
SQN-M-
230323-16
Unit 2 Aux Building Upender Underwater Survey
03/23/2023
SQN-M-
230324-11
Diver survey - repairs on wafer valve
03/24/2023
SQN-M-
230325-3
EPRI Survey [post crud burst shutdown source term
trending]
03/25/2023
SQN-M-
230327-19
2-VLV-063-0634 Breach
03/27/2023
210021
Revision 0
220002
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
Radiation Work
Permits (RWPs)
240065
734' SFP Area - Diving activities in the Spent Fuel Pool to
repair U2 fuel transfer system [transfer tube wafer valve]
03/22/2023
24382
Radiological Hazard Assessment and Exposure Control Self
Assessment
05/16/2022
Self-Assessments
24397
Occupational ALARA Planning and Controls
1/12/2023
CR 1707916
Corrective Action
Documents
CR 1764606
NPG-SPP-05.6.1
Radiation Protection Implementation of 10CFR37 Category
and Category 2 Quantities of Radioactive Material
Revision 3
NPG-SPP-05.9.1
Radioactive Material/Waste Shipments
Revision 10
Procedures
RHSI-13
Administration and Control of Onsite Storage of Low Level
Radioactive Waste
Revision 4
CR 1684128
Radioactive Solid Waste Processing and Radioactive
Material Handling, Storage, and Transportation
08/21/21
Self-Assessments
CR 1752444
Part 37 Self-Assessment
03/21/2022
71151
Miscellaneous
Electronic Dosimeter Dose and Dose Rate Alarm logs
(11/1/2022 through 3/30/2023
Various
CR 1780355
Fallen Unit 2 Generator Neutral Bus
06/01/2023
CR 1781005
Unit 2 neutral bus configuration
06/04/2023
CR 1843684
Ice condenser bays 1 to 12 AHU condensate drain line
clogged
03/20/2022
Corrective Action
Documents
CR 1843794
Remove pool of water from RCP platform 2-4
03/20/2023
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
CR 1811241
Turbine Stop Valve #2 failed to close
10/22/2022
Operability
Evaluations
CA 1811241-001
Perform Past Operability Evaluation on TV-2
10/25/2022