IR 05000390/2020001
| ML20128J219 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 05/05/2020 |
| From: | Tom Stephen NRC/RGN-II |
| To: | Jim Barstow Tennessee Valley Authority |
| References | |
| IR 2020001 | |
| Download: ML20128J219 (14) | |
Text
May 5, 2020
SUBJECT:
WATTS BAR, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000390/2020001 AND 05000391/2020001
Dear Mr. Barstow:
On March 31, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Watts Bar, Units 1 and 2. On April 16, 2020, the NRC inspectors discussed the results of this inspection with Mr. Anthony Williams 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,
/RA/
Thomas A. Stephen, Chief Reactor Projects Branch 5 Division of Reactor Projects
Docket Nos. 05000390 and 05000391 License Nos. NPF-90 and NPF-96
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000390 and 05000391
License Numbers:
Report Numbers:
05000390/2020001 and 05000391/2020001
Enterprise Identifier: I-2020-001-0063
Licensee:
Tennessee Valley Authority
Facility:
Watts Bar, Units 1 and 2
Location:
Spring City, TN 37381
Inspection Dates:
January 01, 2020 to March 31, 2020
Inspectors:
W. Deschaine, Senior Resident Inspector
T. Fanelli, Senior Reactor Inspector
J. Hamman, Resident Inspector
Approved By:
Thomas A. Stephen, 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 Watts Bar, 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
Type Issue Number Title Report Section Status URI 05000390/2018010-01 Potential Failure to Request NRC Approval to Increase the OP deltaT and OT deltaT Response Times 71111.17T Closed URI 05000390/2018010-03 Potential Failure to Maintain Design Requirements of Resistance Temperature Detectors (RTDs)71111.17T Closed URI 05000390/2018010-02 Potential Failure to Perform an 50.59 Evaluation for Auxiliary Building and Containment Isolation 71111.17T Closed NOV 05000390,05000391/20 19013-02 Incomplete and Inaccurate Information for Unit 1 License Amendment 103 and Unit 2 Initial Operating License 92702 Closed
PLANT STATUS
Unit 1 began the inspection period at rated thermal power. On February 19, operators manually tripped the reactor due to an uncontrolled loss of level on steam generator #3 caused by the #3 main feedwater regulating valve going closed for undetermined reasons. Subsequently the licensee determined that the controller for the #3 main feedwater regulating valve had stuck in the closed direction. The controller was replaced and the unit was returned to 100 percent RTP on February 21 and remained at or near 100 percent RTP for the remainder of the inspection period.
Unit 2 began the inspection period at rated thermal power. On March 27, operators commenced a planned down power to take the main turbine offline and complete some secondary repairs.
The unit was returned to 100 percent RTP on March 30 and remained at or near 100 percent 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/readingrm/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. From January 1 - March 19, 2020, the inspectors performed plant status activities described in IMC 2515, Appendix D, Plant Status, and conducted routine reviews using IP 71152, Problem Identification and Resolution. 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 (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 and during that time conducted plant status activities as described in IMC 2515, Appendix D; and observed risk significant activities when warranted. In addition, resident and regional baseline inspections were evaluated to determine if all or portion 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 the cases where it was determined the objectives and requirements could not be performed remotely, management elected to postpone and reschedule the inspection to a later date.
REACTOR SAFETY
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) Unit 2 Residual Heat Removal System Train A and B on March 17, 2020.
(2)2A Emergency Diesel Generator on March 24, 2020.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (3 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) Vital Battery Rooms (Elevation 772) on March 5, 2020.
- (2) Shutdown Board Rooms (Elevation 757) on January 17, 2020.
(3)480V Board Rooms (Elevation 772) on March 5, 2020.
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 February 18, 2020.
71111.06 - Flood Protection Measures
Cable Degradation (IP Section 03.02) (1 Sample)
The inspectors evaluated cable submergence protection in:
- (1) Manhole 5B
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 control room during the following activities:
- Unit 1 manual trip on February 19, 2020, due to an uncontrolled loss of level on steam generator #3 caused by the #3 main feedwater regulating valve closing unexpectedly.
- Unit 1 startup activities on February 20, 2020, following the manual trip.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) Inspectors observed a simulator exam for a reactor scram due to a control rod drive malfunction followed by a pressurizer relief valve being stuck open and a loss of all steam generator feedwater on January 30, 2020.
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)6.9kV Shutdown Power Boards (System 211)
- (2) Essential Raw Cooling Water (System 67)
Quality Control (IP Section 03.02) (1 Sample)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:
(1)2A Emergency Diesel Generator
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) Risk assessment for January 8, 2020, with the 1A-A emergency diesel generator essential raw cooling water supply exposed due to excavation for pipe inspection.
- (2) Risk assessment for the week of February 3, 2020, with the 2A-A emergency diesel generator, out of service for a planned maintenance outage.
- (3) Risk assessment for February 11, 2020, with the 2B motor driven auxiliary feedwater pump breaker swap outside the normal component outage window.
- (4) Risk assessment for March 18, 2020, for high-risk maintenance related to the replacement of an ammeter on the 125 volt vital battery board, I-1.
- (5) Risk assessment for March 26 - 27, 2020, for containment air recirculation fan, out of service due to corrective maintenance.
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (2 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) U2 cold leg accumulator #4 boron concentration was below the technical specification allowable limit of 3,000 ppm.
- (2) Prompt determination of operability for 2A emergency diesel generator due to failure of the lubricating oil circulation pump on the 2A2 engine.
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the following post maintenance test activities to verify system operability and functionality:
(1)1-SI-99-10-B, 62 Day Functional Test of Solid State Protection System (SSPS) Train B and Reactor Trip Breaker B, after replacement of the Universal Board on Train B SSPS, documented in Work Order 121013292.
- (2) Post maintenance test of the B shutdown boardroom chiller following removal of a temporary modification,documented in Work Order 120630699.
- (3) Post maintenance test of the ammeter for the I-1 125 Volt Vital Battery Board, documented in Work Order 116498217.
(4)1-SI-3-902, Turbine Driven Auxiliary Feedwater Pump 1A-S Quarterly Performance Test, after lube oil sampling and coupling inspection, documented in Work Order
===120464133.
(5)1-SI-3-17, 18 month channel calibration of steam generator 2, turbine driven auxiliary feedwater level control loop 1-LPL-3-173, after replacement of transmitter 1-LT-3-173, Work Order # 121169273.
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage Sample (IP Section 03.01)===
- (1) The inspectors evaluated forced outage activities from February 19 to 21, 2020.
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) WO 120556748, 0-SI-82-11-A, Monthly Diesel Generator Start And Load Test DG 1A-A on January 31, 2020.
- (2) WO 120316954, 0-SI-82-16, 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Load Run - Diesel Generator 2B-B, on January 27, 2020.
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) WO 120498940, 2-SI-72-901-B, Containment Spray Pump 2B-B Quarterly Performance Test on January 15, 2020.
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)
- (1) The residents observed the site emergency response to a training drill on February 26, 2020, which began with a high energy steam line break on a steam generator (SG) inside containment. The rapid depressurization and cool down of the SG caused an automatic reactor trip and safety injection. An anticipated transient without scram (ATWS) occurred coincident with the reactor trip/safety injection signal and a reactor coolant pump (RCP) tripped due to internal damage. The damage of the RCP caused fuel damage and a steam generator tube rupture (SGTR) on the SG that the steam line break occurred. Once all of the containment spray pumps tripped and containment pressure started to increase the site declared a General Emergency due to a loss of 2 Fission Product Barriers and a Loss or Potential Loss of the Third.
OTHER ACTIVITIES - BASELINE
71153 - Followup of Events and Notices of Enforcement Discretion Event Followup (IP Section 03.01)
- (1) The inspectors evaluated a Unit 1 manual reactor trip in response to the #3 main feedwater regulating valve to steam generator #3 being in manual with 100% output, and level in the #3 steam generator lowering uncontrolled and licensees response, on February 19,
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL
92702 - Followup on Traditional Enforcement Actions Including Violations, Deviations, Confirmatory Action Letters, Confirmatory Orders, And Alternative Dispute Resolution Confirmatory Orders
The inspectors reviewed the licensees response to NOV 05000390,05000391/2019013-02 and determined that the reason, corrective actions taken and planned to address recurrence, and the date when full compliance will be achieved for this violation is adequately addressed and captured on the docket.
INSPECTION RESULTS
Unresolved Item (Open)
Potential Failure to Request NRC Approval to Increase the OP deltaT and OT deltaT Response Times URI 05000390/2018010-01 71111.17T
Description:
The inspectors reviewed unresolved item (URI)05000390/2018010-01. In 2015, licensee loop current step response (LCSR) testing discovered that the temperature averaging system (TAS) overall response time increased. It could not meet the response time established in the plant Technical Requirements Manual (TRM). Further Westinghouse testing discovered that this appeared to be because the temperature thermowell did not have a tight fit with the resistance temperature detector (RTD).
On 5/23/2015, Design Change Notice (DCN) 66327 performed a 10 CFR 50.59 evaluation and increased the established response time to nine seconds without a license amendment. The inspectors were concerned because NUREG 847 supplement 8, dated 1992, the Safety Evaluation Report (SER), specified, that during initial startup testing, actions will be taken to correct any RTD channel with an overall response time of greater than seven seconds including electronics delay and a ten percent allowance for LCSR test uncertainty.
The inspectors were concerned that, the 10-percent allowance for LCSR test uncertainty was not accounted for in the Westinghouse analyses and that it could have affected the results. In addition, the decrease in margin may have exceeded the acceptable limits.
After further discussions with the licensee and reviewing additional information, no findings were identified.
Licensee Actions: This issue has been captured in the Corrective Action Program (CAP) as CR 1398934, Potential failure to request lic. amendment to change OPdT/OTdT response time
Corrective Action References: CR 1398934 Unresolved Item (Closed)
Potential Failure to Maintain Design Requirements of Resistance Temperature Detectors (RTDs)
URI 05000390/2018010-03 71111.17T
Description:
The inspectors reviewed unresolved item (URI)05000390/2018010-03. The new RTDs receipt documents specified design criteria identified in EQOP-ESE-7 in WCAP 8587 and the EQTR WCAP-8687 Supp. 2-E07A. The installed condition of the RTDs did not appear to meet the design criteria.
After further discussions with the licensee and reviewing additional information, no findings were identified.
Corrective Action Reference(s): CR 1398936
Unresolved Item (Closed)
Potential Failure to Perform an 50.59 Evaluation for Auxiliary Building and Containment Isolation URI 05000390/2018010-02 71111.17T
Description:
The inspectors reviewed unresolved item (URI)05000390/2018010-02. DCN 66459 added relays and wiring to change the actuation system that initiated the Auxiliary Building Isolation (ABI) to the two units Containment Ventilation Isolation (CVI) protective functions. The licensee did not perform a failure modes and effects analysis to determine the negative effects that could degrade the Engineered Safety Features Actuation System (ESFAS) isolation functions when they are required to operate. The inspectors were concerned that the integration of the two ESFAS circuitry could have a detrimental effect. Additional failure points were introduced into these systems.
After further discussions with the licensee and reviewing additional information, no findings were identified.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On April 16, 2020, the inspectors presented the integrated inspection results to Mr.
Anthony Williams and other members of the licensee staff.
THIRD PARTY REVIEWS
Inspectors reviewed Institute on Nuclear Power Operations reports that were issued during the inspection period.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
3-OT-STG-074
Operations Residual Heat Removal System Student Training
Guide
Revision 12
3-OT-STG-082A
Operations Diesel Generator Overview Student Training
Guide
Revision 12
SDD-N3-74-4001
Residual Heat Removal System Description Document
Revision 19
SDD-N3-82-4002
Standby Diesel Generator System Description Document
Revision 25
Procedures
0-SOI-82.03
Revision 16
2-SOI-74.01
Residual Heat Removal System
Revision 17
Fire Plans
AUX-0-757-01
Aux Building 757.0 Elevation
Revision 2
AUX-0-757-02
Aux Building 757.0 Elevation
Revision 4
AUX-0-757-03
Aux Building 757.0 Elevation
Revision 4
AUX-0-772-01
Aux Building 772.0 & 782.0 Elevation
Revision 1
AUX-0-772-02
Aux Building 772.0 Elevation
Revision 5
AUX-0-772-03
Aux Building 772.0 Elevation
Revision 5
Miscellaneous
FPDP-5
Development and Evaluation of Fire Drills
Drawings
Conduit Bank Node Diagram (5A, 5B, 3A, 3B)
Revision 1
Miscellaneous
PM#: 600107659
1E Manhole and Sump Inspection
Revision 13B
Corrective Action
Documents
1601315
Action item from MR a(1) plan to replace the ERCW Pump
breaker micro switches.
4/14/2020
Procedures
N-PT-9
Liquid Penetrant Examination of ASME and ANSI Code
Components and Welds
Revision 39
Work Orders
119482277
Replace silencer exhaust drain nipple assemblies for 2A1 &
2A2
2/5/2020
Corrective Action
Documents
1586128
Miss-incorporated/unincorporated T-week comments results
in unnecessary unavailability for AFW
2/11/2020
Miscellaneous
Operators Risk Evaluation for Watts Bar Unit 1
March 18,
20
Technical Evaluation for Work Order 120604956
Corporate Exception Concurrence for Work Order 20604956
09/25/2019
Pressurized Water Reactor Operational Risk Review - Red
Sheet, for WO 116498217
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Work Activity Risk Characterization for Work Order 20604956
09/10/2019
0-MI-236.010
Periodic 125V Vital Battery Board I Relay and Indicating
Instrument Test
Procedures
NPG-SPP-07.3
Work Activity Risk Management Process
NPG-SPP-
09.11.1
Equipment Out of Service Management
Revision 13
Work Orders
Corrective Action
Documents
Condition Report
22853
Miscellaneous
Unit 2 Operations Logs
2/13/2019
Standing Order
19-34
Adverse Condition Monitoring Plan for U2 CLA #4 In-leakage
10/31/2019
WBN-VTD-E147-
0010
Engine Maintenance Manual for the EMO Lubricating Oil
System
Revision 2
Corrective Action
Documents
Condition Reports 1576237, 1576152, 1576033
Work Orders
21013292
Annunciator Issue During performance of 1-SI-30-42
01/01/2020
21169273
1-SI-3-17, 18 month channel calibration of steam generator 2
turbine driven auxiliary feedwater level control loop 1-LPL-3-
173 after replacement of transmitter 1-LT-3-173
Miscellaneous
Trip Report 2-19-2020
Work Orders
21123878
Steam Generator #3 Feedwater inlet flow controller
replacement
2/19/2020
Procedures
0-SI-82-11-A
Monthly Diesel Generator Start and Load Test DG 1A-A
0-SI-82-16
Revision 26
2-SI-72-901-B
Containment Spray Pump 2B-B Quarterly Performance Test
Work Orders
Work Order 20498940, 120556748
Miscellaneous
WBN Feb 2020 TD Team A
2/26/2020
2702
Corrective Action
Documents
244275
Identification of 10 CFR 50.9 Issue
244348
Level 2 Evaluation
Revision 1
244348
CSST A/B potentially outside GDC-17 criteria for TS use
244348
Level 2 Evaluation
Revision 0
245056
Non-Conservative Tech Spec 3.8.1 (U1&2)
1567139
NRC Violation Checklist
Revision 1
Miscellaneous
CNL-190110
Watts Bar, Application to Revise Technical Specifications 3.8.1
2/17/2019