IR 05000327/2021001

Integrated Inspection Report 05000327/2021001 and 05000328/2021001

ML21117A040
Person / Time
Site:	Sequoyah
Issue date:	04/27/2021
From:	Tom Stephen Division Reactor Projects II
To:	Jim Barstow Tennessee Valley Authority
References
IR 2021001
Download: ML21117A040 (14)

Text

April 27, 2021

SUBJECT:

SEQUOYAH, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000327/2021001 AND 05000328/2021001

Dear Mr. Barstow:

On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Sequoyah, Units 1 and 2. On April 8, 2021, 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 involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.

If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:

Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; the Director, Office of Enforcement; and the NRC Resident Inspector at Sequoyah, Units 1 and 2.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; and the NRC Resident Inspector at 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 Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Thomas A. Stephen, 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: 05000327/2021001 and 05000328/2021001 Enterprise Identifier: I-2021-001-0055 Licensee: Tennessee Valley Authority Facility: Sequoyah, Units 1 and 2 Location: Soddy Daisy, TN 37379 Inspection Dates: January 01, 2021 to March 31, 2021 Inspectors: D. Hardage, Senior Resident Inspector N. Childs, Resident Inspector Approved By: Thomas A. Stephen, 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 to Properly Align 2B Elevation 669 Penetration Room Coolers Flow Control Valve Renders Cooler Non-functional Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71152 Systems NCV 05000328/2021001-01 Conservative Open/Closed Bias A self-revealed Green finding and associated non-cited violation (NCV) of Sequoyah Unit 2 Technical Specification 5.4.1, Procedures, was identified when the licensee failed to properly align 2-FCV-67-348 (2B 669 elevation penetration room coolers flow control valve) in accordance with quality-related procedure 0-PI-SFT-067-0003.B, ERCW Train B Manipulation for Plant Activities. The misalignment caused the 2B-B 669 penetration room cooler to be non-functional for the period of November 19, 2020 through November 23, 2020.

Additional Tracking Items

None.

PLANT STATUS

Unit 1 and 2 operated at or near rated thermal power 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 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.

Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the Coronavirus Disease 2019 (COVID-19), resident inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time, the resident inspectors performed periodic site visits each week; conducted plant status activities as described in IMC 2515, Appendix D, Plant Status; observed risk-significant activities; and completed on-site portions of IPs. In addition, resident and regional baseline inspections were evaluated to determine if all or portions of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on-site. The inspections documented below met the objectives and requirements for completion of the IP.

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 for extreme cold conditions on February 16, 2021.

71111.04 - Equipment Alignment

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

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

(1) Unit 1 component cooling water system (CCS) with the 1A1 CCS heat exchanger out of service for cleaning on January 20, 2021

(2) Essential raw cooling water (ERCW) with the PB ERCW pump out of service for maintenance on January 26, 2021

(3) 2B emergency diesel generator (EDG) with the 2A EDG out of service for maintenance on February 2, 2021

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

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 1 EDG system on March 2, 2021.

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 cable spreading rooms on January 12, 2021

(2) Unit 1 and Unit 2 vital battery rooms 1 - 4 on January 14, 2021

(3) ERCW Building on January 26, 2021

(4) EDG, Elevation 740.5 on February 7, 2021

(5) EDG, Elevation 722 on March 1, 2021 Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Partial)

(1) (Partial)

The inspectors evaluated fire brigade performance on February 25, 2021.

71111.06 - Flood Protection Measures

Cable Degradation (IP Section 03.02) (1 Sample)

The inspectors evaluated cable submergence protection in:

(1)

• 0-MNWY-317-HH52A1

• 0-MNWY-317-HH52A2

71111.07A - Heat Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) The inspectors observed the 1A2 CCS heat exchanger inspection and state of cleanliness on January 5, 2021.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)

(1) The inspectors observed and evaluated licensed operator performance in the main control room during post maintenance testing of the 1B EDG on February 24, 2021.

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

(1) The inspectors observed and evaluated a simulator examination scenario on February 4, 2021.

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) Failure of unit station service transformer 2B multifunction protective relay 2-RLY-241-RZ/387 due to incorrect as-left angular displacement setting in the relay following calibration on April 27, 2020

(2) Unit 2 - Function 088-B, Containment Isolation and Integrity, (a)(1) evaluation due to multiple local leak rate test failures of inboard containment isolation valve 2-VLV-313-0734 on February 24, 2021

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 3 - January 9, 2021, including protection equipment reviews for scheduled maintenance on the 1A2 component cooling water heat exchanger and emergent maintenance on the D station air compressor.

(2) Unit 1 and 2, week of January 17 - January 23, 2021, including protection equipment reviews for scheduled maintenance on the 1A1 component cooling water heat exchanger and the C station air compressor.

(3) Unit 1 and 2, week of January 31 - February 6, 2021, including protection equipment reviews for scheduled maintenance on the 2A EDG, 1A safety injection pump, and ERCW pump well A-A inspection.

(4) Unit 1 and 2, week of February 21 - February 27, 2021, including protection equipment reviews for scheduled maintenance on the 1B EDG and 2B containment spray heat exchanger.

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) 2C-A lower compartment cooler non-functional due to temperature control valve 2-TCV-67-92 failure to stroke open on January 19, 2021 (CR 1666966)

(2) ERCW discharge piping from containment spray heat exchanger found below minimum wall thickness on February 1, 2021 (CR 1668113)

(3) J-A ERCW pump shaft packing collar broken on March 16, 2021 (CR 1679066)

(4) Potential missed surveillance testing of containment airlock on January 12, 2021 (CR

===1657759)

(5) 2B-B EDG when loaded between 4.62 MW and 4.8 MW experienced two load rejections on March 10, 2021 (CR 1677777)

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-20-1501-001, U1 refuel water storage tank Barton Level Transmitter Replacement 1-LT-063-050-D

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) ===

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

(1) Work Order (WO) 121107347, Component Cooling Heat Exchanger 1A2 Clam and MIC inspection on January 7, 2021

(2) WO 121080021, Fire Protection Header Replacement in Unit 1 690 Pen Room on January 12, 2021.

(3) WO 121107366, DG water cooler 2A-2 for clams, mic and other degradation on February 3, 2021

(4) WO 121272630, Check auto start sequence and perform overspeed trip test on 2B EDG on February 10, 2021

(5) WO 121927792, Replace defective circuit in rod control logic cabinet 1-PNL-085-L122 on February 11, 2021

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)

(1) 1-SI-OPS-082-007.B, Electrical Power System Diesel Generator 1B-B on February 24, 2021

(2) O-SI-OPS-092-078.0, Power Range Neutron Flux Channel Calibration by Heat Balance Comparison, Unit 2 on March 15, 2021

Inservice Testing (IP Section 03.01) (2 Samples)

(1) 2-SI-SXP-003-201.A, Motor Driven Auxiliary Feedwater Pump 2A-A Performance Test on January 20, 2021

(2) 2-SI-SXP-003-201.S, Turbine Driven Auxiliary Feedwater Pump 2A-S Performance Test on March 17, 2021

71114.06 - Drill Evaluation

Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)

(1) Emergency preparedness drill conducted on March 10,

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 03.10) ===

(1) Unit 1 RCS Activity (January 2020 - December 2020)

(2) Unit 2 RCS Activity (January 2020 - December 2020)

BI02: RCS Leak Rate Sample (IP Section 03.11) (2 Samples)

(1) Unit 1 RCS Leakage (January 2020 - December 2020)

(2) Unit 2 RCS Leakage (January 2020 - December 2020)

71152 - Problem Identification and Resolution

Annual Follow-up of Selected Issues (IP Section 02.03) (2 Samples)

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

(1) 2B 669 penetration room coolers flow control valve mispositioned

(2) Main Control Room air conditioner tripped on low oil pressure

INSPECTION RESULTS

Failure to Properly Align 2B Elevation 669 Penetration Room Coolers Flow Control Valve Renders Cooler Non-functional Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.14] - 71152 Systems NCV 05000328/2021001-01 Conservative Open/Closed Bias A self-revealed Green finding and associated non-cited violation (NCV) of Sequoyah Unit 2 Technical Specification 5.4.1, Procedures, was identified when the licensee failed to properly align 2-FCV-67-348 (2B 669 elevation penetration room coolers flow control valve)in accordance with quality-related procedure 0-PI-SFT-067-0003.B, ERCW Train B Manipulation for Plant Activities. The misalignment caused the 2B-B 669 penetration room cooler to be non-functional for the period of November 19, 2020 through November 23, 2020.

Description:

On November 23, 2020, while performing post maintenance testing of the 2B-B 669 penetration room cooler, 2-XDV-67-348 (three-way air supply valve for 2-FCV-67-348)was discovered in the closed position. With 2-XDV-67-348 in the closed position, the flow control valve was not capable of automatically opening on cooler start, rendering the cooler non-functional. With the cooler non-functional, the Unit 2 Train B ECCS was declared inoperable as required by 0-SO-30-10 Attachment 9, Plant Operability Impacts (Tech Spec/TRM) Associated with Engineered Safety Feature (ESF) Coolers.

The 2B 669 elevation penetration room cooler is an ESF equipment cooler listed in UFSAR Section 9.4.2.2.3, Safety Feature Equipment Coolers, and is required to start and operate upon receipt of an auxiliary building isolation (ABI) signal or whenever the temperature setpoint is reached in the penetration room. The penetration room cooler mitigates accident effects to emergency core cooling system (ECCS) equipment located within the room by maintaining the temperature within the room below the design limit of 110 degrees F.

The licensee determined that the last manipulation of the three-way valve was during the November 19, 2020 performance of 0-PI-SFT-067-003.B, ERCW Train B Manipulation for Plant Activities. Further investigation revealed that the three-way air supply valve (2-XDV-67-348) had no existing valve position labeling. During the November 19, 2020 performance of 0-PI-SFT-067-003.B, plant personnel completed the flow control valve alignment under the assumption that the air supply valve position labels (if they existed) would be identical to similar valves in the area and positioned 2-XDV-67-348 as such. However, they failed to recognize that 2-XDV-67-348 was configured differently than those similar valves in the area which resulted in incorrect alignment for flow control valve 2-FCV-67-348.

Corrective Actions: The three-way valve was returned to its normal position and the flow control valve was verified to operate properly. An extent of condition review found additional room cooler three-way valves without valve position labels. A corrective action was initiated to install appropriate valve labeling to 2-XDV-67-348 and the additional three-way valves identified through extent of condition review.

Corrective Action References: CR 1654207

Performance Assessment:

Performance Deficiency: The inspectors determined that the licensees failure to properly align the three-way air supply valve for 2-FCV-67-348 (2B 669 penetration room coolers flow control valve) in accordance with quality-related procedure 0-PI-SFT-067-0003.B, ERCW Train B Manipulation for Plant Activities, was a performance deficiency. Specifically, the misalignment caused the 2B-B 669 penetration room cooler to be non-functional for the period of November 19, 2020 through November 23, 2020.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the penetration room cooler supports operability of ECCS components in the room, therefore, the condition presented reasonable doubt with respect to Unit 2 Train B ECCS operability. The licensee performed a GOTHIC analysis in order to determine the impact on penetration room temperature with the penetration cooler non-functional and to demonstrate Unit 2 Train B ECCS operability. The performance deficiency is also similar to IMC 0612, Appendix E, Example 3e2 (more-than minor) which states that regardless of final operability or functionality, the as-found condition was such that there was reasonable doubt with respect to operability which affected the assurance of availability and reliability.

Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined that the finding screened to Green because licensee analysis determined that Unit 2 Train B ECCS operability was maintained. The GOTHIC analysis determined that, with no functioning room coolers, the penetration room could reach a maximum temperature of 161.3 degrees F during accident conditions, which exceeds the rooms temperature design limit of 110 degrees F as documented in SQN Environmental Design Criteria SQN-DC-V-21.0. Further analysis of the active ECCS components within the room using a 161.3 degrees F room temperature determined that the elevated temperature would not challenge operability of those components. Therefore, the licensee concluded that the 2B elevation 669' penetration room cooler was not required for Unit 2 Train B ECCS to perform its safety function.

Cross-Cutting Aspect: H.14 - Conservative Bias: Individuals use decision making-practices that emphasize prudent choices over those that are simply allowable. A proposed action is determined to be safe in order to proceed, rather than unsafe in order to stop. Specifically, absent valve position labeling, plant personnel made the decision to position 2-XDV-67-348 under the assumption that it was configured identically to other three-way room cooler valves.

Enforcement:

Violation: Technical Specification 5.4.1, Procedures, states in part that written procedures shall be established, implemented, and maintained for applicable procedures recommended in Reg Guide 1.33, Revision 2. Procedures for Auxiliary or Reactor Building Heating and Ventilation are included in the list of applicable procedures in Reg Guide 1.33, Revision 2. Contrary to the above, the licensee failed to properly implement quality-related procedure 0-PI-SFT-067-003.B on November 19, 2020 when plant personnel did not align 2-FCV-67-348 in accordance with the procedure resulting in non-functionality of the 2B-B 669 penetration room cooler.

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

EXIT MEETINGS AND DEBRIEFS

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

• On April 8, 2021, 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 Procedures 0-OPS-000-006.0 Freeze Protection Revision 65

NPG-SPP-07.1.6 On Line Work Control Power System Alerts /Offsite Power Revision 7

71111.04 Procedures 0-SI-OPS-082- Diesel Generator Operability Verification Revision 20

007.0

0-SO-67-1 Emergency Raw Cooling Water Revision 113

0-SO-70-1 Component Cooling Water System "A" Train Revision 60

0-SO-82-1 Diesel Generator 1A-A Revision 62

0-SO-82-2 Diesel Generator 1B-B Revision 63

0-SO-82-4 Diesel Generator 2B-B Revision 65

71111.05 Fire Plans AUX-0-749-01 Pre-Fire Plans, Auxiliary Building Elevation 749' (Unit 1) Revision 7

AUX-0-749-02 Pre-Fire Plans, Auxiliary Building Elevation 749' (Unit 2) Revision 8

CON-0-706-00 Pre-Fire Plan, Control Building El. 706 Revision 8

DGB-0-722-00 Fire Protection Pre-Fire Plans Diesel Generator Building - El. Revision 7

2

DGB-0-740.5-00 Fire Protection Pre-Fire Plans Diesel Generator Building - El. Revision 6

740.5

ERCW-0-688-00 Pre-Fire Plan Essential Raw Cooling Water Station, Revision 2

Elevation 688

ERCW-0-704-00 Pre-Fire Plan Essential Raw Cooling Water Station, Revision 2

Elevation 704

ERCW-0-720-00 Pre-Fire Plan Essential Raw Cooling Water Station, Revision 3

Elevation 720

71111.06 Work Orders WO 121096806 Inspect and repair manhole/handhole 01/04/2021

71111.07A Corrective Action CR 1662219 Increase in amount of clams in 1A2 CCS HX precleaning 01/05/2020

Documents

Procedures NPG-SPP-09.14 Generic Letter (GL) 89-13 Implementation Revision 5

Work Orders WO 121107347 CCS heat exchanger 1A2 clam and mic inspection 01/05/2020

71111.11Q Miscellaneous Simulator Exam ASLBIC with loss of 125VDC Vital Bus Revision 11

Guide SEG# SX-

2

Procedures 0-SO-30-8 Containment Pressure Control Revision 39

1-SI-OPS-082- Electrical Power System Diesel Generator 1B-B Revision 74

Inspection Type Designation Description or Title Revision or

Procedure Date

007.B

71111.12 Corrective Action CR 1604118 PRG Relay for USST 2B as left settings were not restored 04/27/2020

Documents after calibration

CR 1606789 Evaluate fleet PRG performance to identify performance 05/08/2020

improvement opportunities

Miscellaneous CDE #3102 USST 2B trip due to incorrectly set relay 2-RLY-241-RZ/387 05/21/2020

Procedures NPG-SPP-03.4 Maintenance Rule Performance Indicator Monitoring, Revision 3

Trending, and Reporting - 10CFR50.65

TI-4 Maintenance Rule Performance Indicator Monitoring, Revision 36

Trending, and Reporting - 10CFR50.65

71111.13 Procedures 0-GO-16 System Operability Checklists Revision 26

0-SI-OPS-082- Diesel Generator Operability Verification Revision 20

007.0

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

007.W

1-SO-70-1 Verification of ERCW Temperature with CCS Hx 1A1 or 1A2 Revision 60

10 Out-of-Service

71111.15 Corrective Action CR 1680801 Inspect EDG 2A-A PT secondary fuses (Extent of Condition) 03/23/2021

Documents CR Action Evaluate OEM response to amount of leakage from ERCW 09/11/2015

1042783-001 pump with no packing installed

Miscellaneous TR 7.5.3 assessment for 2C lower compartment cooler unit 01/26/2021

non-functional due to TCV-67-92 failing to stroke full open

EWR 21-DEC- Determine remaining service life in the ERCW pipe wall Revision 2

067-012 downstream of valve 1-FCV-67-124

SQN-0-21-016 PRA Evaluation Response for CR 1666966 Revision 0

Operability Prompt Determination of Operability for CR 1668113 02/04/2021

Evaluations

71152 Corrective Action CR 1680531 Inadvertent chiller trip while performing WO 121285427 03/22/2021

Documents

11