IR 05000445/2022002
| ML22213A116 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/05/2022 |
| From: | Greg Werner NRC/RGN-IV/DORS |
| To: | Peters K Vistra Operations Company |
| References | |
| IR 2022002 | |
| Download: ML22213A116 (25) | |
Text
August 05, 2022
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000445/2022002 AND 05000446/2022002
Dear Mr. Peters:
On June 30, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Comanche Peak Nuclear Power Plant, Units 1 and 2. On July 13, 2022, the NRC inspectors discussed the results of this inspection with Mr. John Dreyfess, Director, Organizational Effectiveness, and other members of your staff. The results of this inspection are documented in the enclosed report.
Three findings of very low safety significance (Green) are documented in this report. Two of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the significance or severity of the violations 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 IV; the Director, Office of Enforcement; and the NRC Resident Inspector at Comanche Peak Nuclear Power Plant, Units 1 and 2.
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 IV; and the NRC Resident Inspector at Comanche Peak Nuclear Power Plant, 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, Gregory E. Werner, Chief Projects Branch B Division of Operating Reactor Safety Docket Nos. 05000445 and 05000446 License Nos. NPF-87 and NPF-89
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000445 and 05000446
License Numbers:
Report Numbers:
05000445/2022002 and 05000446/2022002
Enterprise Identifier:
I-2022-002-0003
Licensee:
Vistra Operations Company LLC
Facility:
Comanche Peak Nuclear Power Plant, Units 1 and 2
Location:
Glen Rose, TX
Inspection Dates:
April 1, 2022, to June 30, 2022
Inspectors:
D. Antonangeli, Health Physicist
B. Baca, Health Physicist
N. Day, Resident Inspector
J. Drake, Senior Reactor Inspector
J. Ellegood, Senior Resident Inspector
S. Hedger, Senior Emergency Preparedness Inspector
J. O'Donnell, Senior Health Physicist
Approved By:
Gregory E. Werner, Chief
Projects Branch B
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Comanche Peak Nuclear Power 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
Non-functional Fire Barrier Between Unit 2 Safety Chillers Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000446/2022002-01 Open/Closed
[H.12] - Avoid Complacency 71111.05 The inspectors identified a Green finding and associated non-cited violation of License Condition 2.G for failing to maintain a 1-hour fire barrier intact. The inspectors identified a fire door that separated the safety chillers was not secured, and subsequent inspection demonstrated the door would not close without assistance about 20 percent of the time. This fire door separated opposite trains of safety chillers that are required to attain and maintain safe shutdown.
Main Feedwater Pump Trip Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05000445/2022002-02 Open/Closed
[H.1] -
Resources 71111.12 The inspectors reviewed a self-revealed Green finding when the licensee failed to assemble main feedwater pump 1-01 turbine casing in accordance with manufacturer drawings.
Specifically, General Electric drawing 125D431EC includes tolerances for gaps between seal components and forms part of the design bases for the facilities; however, the tolerances were not followed. Because of these out of specification tolerances, internal corrosion and degradation caused an automatic trip of main feedwater pump 1-01.
Condensate Storage Tank Level Inaccuracies.
Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000445,05000446/2022002-03 Open/Closed
[H.13] -
Consistent Process 71152A The inspectors identified a Green finding and associated violation of 10 CFR 50, appendix B,
Criterion XVI for the licensees failure to correct a condition adverse to quality. Specifically, the licensee identified in 2017 that level indication of the condensate storage tanks was adversely influenced by nitrogen overpressure resulting in non-conservative level indications. The licensee did not correct the condition until 2022 following inspector inquiries on the 2017 condition report.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000445/2020-001-00 LER 2020-001-00 for Comanche Peak Nuclear Power Plant, Main Feedwater Pump Failure to Trip 71153 Closed
PLANT STATUS
Unit 1 began the inspection period at 100 percent power. On April 10, 2022, Unit 1 shutdown for refuel outage 1RF22, which concluded on May 15, 2022. On May 20, 2022, Unit 1 returned to 100 percent power and operated at or near 100 percent power for the remainder of the inspection period.
Unit 2 began the inspection period at or near 100 percent power. On May 2, 2022, the licensee reduced power to about 67 percent to repair a heater drain pump. On May 5, 2022, Unit 2 returned to 100 percent power and remained there 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.
REACTOR SAFETY
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) Unit 1, safety chiller 1-05 per work clearance 1RF22 0183 on April 28, 2022
- (2) Unit 2, solid state protection system and blackout sequencer following K609 relay test on May 25, 2022, using work order 5980561
- (3) Unit 2, remote shutdown panel following station service water surveillance on June 10, 2022, using work order 5985961
- (4) Unit 2, solid state protection system and blackout sequencer following K616 relay test on June 15, 2022, using work order 5987517
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)turbine building on May 20, 2022
- (2) Unit 1, safety chiller on June 15, 2022
- (3) Unit 2, safety chiller on June 15, 2022
- (4) Unit 1, auxiliary feedwater pump rooms on June 22, 2022
- (5) Unit 2, auxiliary feedwater pump rooms on June 23, 2022
71111.06 - Flood Protection Measures
Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)
The inspectors evaluated internal flooding mitigation protections.
- (1) The inspectors evaluated internal flooding mitigation protections in the auxiliary feedwater pump rooms for Units 1 and 2 on June 23-24, 2022.
71111.08P - Inservice Inspection Activities (PWR) PWR Inservice Inspection Activities Sample (IP Section 03.01)
The inspectors verified that the Unit 1 reactor coolant system boundary, steam generator tubes, reactor vessel internals, risk-significant piping system boundaries, and containment boundary are appropriately monitored for degradation and that repairs and replacements were appropriately fabricated, examined and accepted by reviewing the following activities from April 18 to 28, 2022:
(1)03.01.a - Nondestructive Examination and Welding Activities
ultrasonic examination residual heat removal, TBX-2-2501-6, pipe to elbow, FW-6
ultrasonic examination residual heat removal, TBX-2-2501-7, elbow to pipe, FW-7
ultrasonic examination residual heat removal, TBX-2-2501-31, elbow to pipe, FW-31
ultrasonic examination residual heat removal, TBX-2-2501-38, elbow to pipe, FW-38
visual examination component cooling water, CC-1-AB-004-H4, sway strut
visual examination component cooling water, TB-2-2536-H2, restraint
dye penetrant examination containment spray, TBX-2-2536-H2, 8 lugs
weld package for repairs on the main feedwater system for valve FW-2837, welds FW-1, FW-2, FW-3, FW-4, and FW-5.
03.01.b - Pressurized-Water Reactor Vessel Upper Head Penetration Examination Activities
The inspector reviewed the non-destructive examination report for the reactor vessel upper head penetration examination activities which consisted of an ultrasonic examination of all control rod drive motor nozzles and a demonstrated volumetric leak path assessment of all J-groove welds and supplemental eddy current examination of 35 control rod drive motor nozzle inside surfaces.
03.01.c - Pressurized-Water Reactor Boric Acid Corrosion Control Activities
The following boric acid screenings and evaluations were reviewed:
CR-2020-008917, CR-2020-002581, CR-2020-004812, CR-2020-007762, CR-2020-008354, CR-2020-008917 03.01.d - Pressurized-Water Reactor Steam Generator Tube Examination Activities
The inspection consisted of a 100 percent full length of all tubes with bobbin coil probe. The data analysis was performed remotely. The primary side inspection included all tubes in all steam generators, consisting of 100 percent full length bobbin and rotating pancake probe, as well as 100 percent +Point probe inspection of the hot leg top of tube sheet, and additional inspections of dents/dings, portions of the cold leg tube sheet, and special interest examinations.
The secondary side integrity inspection included the top of tube sheet sludge lancing in all SGs, upper tube bundle visual inspection in SG-1, and top of tube sheet foreign object search and retrieval in all steam generators.
No tubes exhibited degradation exceeding the tube integrity criteria provided in the degradation assessment for the refueling outage 1RF22.
No tubes required in-situ pressure testing to support the condition monitoring assessment based on the degradation assessment and Electric Power Research Institute in-situ pressure test guidelines.
No tube leakage was reported during this operating interval.
Problem Identification and Resolution review of Inservice items
The inspector evaluated a sample of 22 condition reports associated with inservice inspection activities. No findings or violations of more than minor significance were identified.
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 Unit 1 shutdown on May 10, 2022.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator valve training on June 14, 2022, and simulator exercise on June 22, 2022.
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) Unit 2, containment ventilation system VAC
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, refueling outage 22 risk assessment
- (2) Unit 1, reactor head lift on April 18, 2022
- (3) Unit 1, entry to mid loop and vacuum fill on May 4 and 5, 2022
- (4) Unit 1, defense in depth and guarded equipment postings on April 25, 2022
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, emergency diesel generator 2-02 with A phase current differential relay flag per IR 2022-002203 (2)aggregate review of open non-conforming/degraded conditions prior to Unit 1 start up following 1RF22
- (3) Unit 2, turbine driven auxiliary feedwater pump per issue report 2022-3800 (4)reactor coolant system with elevated leakage after refueling outage per condition report 2022-3607
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)gag on 1-HV-2321, Unit 1 main feedwater pump 1A suction valve
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (7 Samples)
The inspectors evaluated the following post-maintenance testing activities to verify system operability and/or functionality:
(1)low power physics testing on May 13, 2022 (2)visual examination of Unit 1 loop rooms on May 12, 2022, per work order 5772042.
- (3) Unit 1, emergency diesel generator 1-01 post maintenance test on May 4, 2022, per work order 5962519
- (4) Unit 1, digital rod position indication module replacement and post work testing per work order 5973073 on May 10, 2022
- (5) Unit 1, turbine driven auxiliary feedwater pump following governor inspection per work order 59743802 on May 12, 2022
- (6) Units 1 and 2 main feedwater pump oil samples per work orders 22-196845, 22-198367, 22-139046, 22-249151 and 22-249294 on May 31, 2022
- (7) Unit 1, motor driven auxiliary feedwater pump 1-01 test following breaker repairs per work order 22-167436
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated 1RF22 activities from April 10 to May 14, 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) (5 Samples)
(1)fuel transfer tube concrete inspection per General Visual Examination 1RF22 (I4)-VT-35 on April 25, 2022 (2)integrated leak rate test on per work order 4776569 on May 4, 2022
- (3) Unit 1, steam generator 1-03 safety relief valve 0095 per work order 5904076 on April 8, 2022 (4)feedwater isolation valve stroke time testing on May 10, 2022 (5)train B diesel generator integrated test sequence per work order 5966035
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) Unit 2, service water pump 2-01 in service test per work order 22-103231 on May 3, 2022
Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)
(1)local leak rate test on Unit 1 charging pump to reactor coolant system isolation valve 1-8105 on April 6, 2022 per work order 5909118
71114.06 - Drill Evaluation
Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)
The inspectors evaluated:
- (1) Emergency Response Organization green team drill on June 22, 2022
71114.08 - Exercise Evaluation - Scenario Review
Inspection Review (IP Section 02.01 - 02.04) (1 Sample)
- (1) The inspectors reviewed the licensee's preliminary exercise scenario that was submitted to the NRC on May 25, 2022, (ADAMS Accession Nos. ML22152A051 and ML22152A052) for the exercise scheduled to occur on July 26-27, 2022. The inspectors discussed the preliminary scenario with Mr. P. Allen, Manager, Emergency Preparedness, and other members of the emergency preparedness staff on June 23, 2022. The inspectors' review does not constitute NRC approval of the scenario.
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 radiologically controlled area (2)workers exiting the radiologically controlled area at Unit 1 during a refueling outage
Radiological Hazards Control and Work Coverage (IP Section 03.04) (4 Samples)
The inspectors evaluated the licensee's control of radiological hazards for the following radiological work:
(1)setup and breach of a residual heat removal 1-01 discharge safety relief valve located on the 808' elevation of the Unit 1 containment building (2)inservice inspection of the reactor vessel head while situated on the head stand located on the 872' elevation of the Unit 1 containment building (3)manway removal on steam generator 1-01 located on steam generator platform at the 825' elevation in the Unit 1 containment building (4)nozzle dam installation for steam generator 1-01 located on the steam generator platform at the 825' elevation in the Unit 1 containment building High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (4 Samples)
The inspectors evaluated licensee controls of the following high radiation areas and very high radiation areas (VHRA):
- (1) VHRA - reactor building sump room access located on the 808' elevation of the Unit 1 containment building.
- (2) VHRA - fuel transfer tube access located on the 860' elevation of the Unit 1 fuel handling building.
- (3) VHRA - fuel transfer tube access located on the 860' elevation of the Unit 2 fuel handling building.
(4)high radiation area - regenerative heat exchanger room located on the 832' elevation of the Unit 1 containment building.
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.
71124.03 - In-Plant Airborne Radioactivity Control and Mitigation
Temporary Ventilation Systems (IP Section 03.02) (2 Samples)
The inspectors evaluated the configuration of the following temporary ventilation systems:
(1)steam generator ventilation system in Unit 1 (2)residual heat removal system discharge safety relief valve breach in Unit 1
Use of Respiratory Protection Devices (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated the licensees use of respiratory protection devices.
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS05: Safety System Functional Failures (SSFFs) Sample (IP Section 02.04)===
- (1) Unit 1 April 1, 2021, through March 31, 2022
- (2) Unit 2 April 1, 2021, through March 31, 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) The inspectors reviewed the licensee's actions associated with correction of level indication errors in the condensate storage tanks (CST). In 2017 the licensee documented that the CST level instruments were affected by nitrogen over pressure in the tank, creating a condition where overpressure could mask insufficient inventory in the CST to meet accident analysis. Although documented in the corrective action program, the licensee failed to address the condition until interaction with the inspectors in 2021.
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) Closed LER 05000445/2020-001-00, Main Feedwater Pump Failure to Trip (ADAMS Accession No. ML21041A178). The inspectors performed a partial sample of this LER in inspection report 05000455/2022-001 (ADAMS Accession No. ML22109A182).
INSPECTION RESULTS
Non-functional Fire Barrier Between Unit 2 Safety Chillers Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000446/2022002-01 Open/Closed
[H.12] - Avoid Complacency 71111.05 The inspectors identified a Green finding and associated non-cited violation of License Condition 2.G for failing to maintain a 1-hour fire barrier intact. The inspectors identified a fire door that separated the safety chillers was not secured, and subsequent inspection demonstrated the door would not close without assistance about 20 percent of the time. This fire door separated opposite trains of safety chillers that are required to attain and maintain safe shutdown.
Description:
On April 5, 2022, the inspectors performed a plant status tour of the Unit 2 safety chillers. During the tour, the inspectors noted that the door separating the train A and B safety chillers, door E-1B was not latched. Subsequent checks to see if the door would close and latch without assistance revealed the door would not close and latch about 20 percent of the time. Although the licensee swiftly repaired the door, the inspectors again noted that the door was not latched on June 10, 2022. At the time, testing of the door confirmed that it would consistently close without assistance.
The safety chillers provide cooling to multiple components including safety-related switchgear, auxiliary feedwater pumps, emergency safety feature pumps and component cooling water pumps. The Fire Hazards Analysis (FHA), section III, paragraph 4.2.1.6 identified the safety chillers as a support system for various trains of systems needed for safe shutdown. As such, loss of both trains of safety chillers would compromise the ability to reach and achieve safe shutdown. The FHA described the barrier as a 1-hour barrier consisting of a partial height wall with ionization fire detectors and a wet-pipe sprinkler system. The FHA forms part of the license bases of Comanche Peak and is discussed in the Final Safety Analysis Report (FSAR), section 9.5.1. The FSAR states that Fire doors located in fire barriers are normally closed or are automatically closed by listed closure devices and released by solenoids, thermal-links, or electro-thermal links.
The inspectors, over the course of several quarters noted multiple examples of doors that were not in the correct configuration:
Feedwater isolation room door not properly dogged
Water tight door to containment spray pump room not properly dogged
Door between 810 hallway and stairs frequently not latched
During main steam safety testing, submarine door was not properly dogged.
Individually, except for door E-1B, each of the other fire doors not closing is minor; however, the trend indicated licensee personnel were not attentive to fire barrier integrity.
Corrective Actions: The inspectors secured the door prior to leaving the area and informed the shift manager. Subsequent inspection by site personnel identified that latch was sticking and corrected the condition by cleaning the latch. The licensee has subsequently initiated actions, including establishing a standard to challenge doors following use, disseminating door closure requirements in multiple formats, and conducting focused observations of door use.
Corrective Action References: CR-2022-2499
Performance Assessment:
Performance Deficiency: The licensee failed to ensure the fire door between the Unit 2 safety chillers was closed and latched. The site safety manual requires personnel to ensure doors are properly configured after passing through the door.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors 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. The inspectors reviewed Inspection Manual Chapter (IMC) 0612, Appendix E, Examples of Minor Issues, dated December 10, 2020, and determined that this performance deficiency was similar to the more-than-minor example 4.j. in that the fire barrier was compromised, which could have impacted both trains of the safety chillers which are needed to attain and maintain safe shutdown conditions.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The inspectors used IMC 0609, Appendix F, attachment 1, "Fire Protection Significance Determination Process Worksheet" dated May 2, 2018, to screen the significance of this finding. Per Step 1.4.4, Question 1.4.4-B, since there was adequate automatic fire suppression on both sides of the 1-hr fire door barrier, the finding screened to Green.
Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. The inspectors concluded that the individuals failed to ensure the door was closed; did not recognize that the door was degraded; and failed to implement error reduction tools.
Enforcement:
Violation: License Condition2.g of the facility operating license states, in part that that the site will comply with their fire protection program as described in the FSAR.. Section 9.5.1, Fire Protection System, of the FSAR, which contains the description of the fire protection program states, in part, that "Fire doors located in fire barriers are normally closed or are automatically closed by listed closure devices and released by solenoids, thermal-links, or electro-thermal links." Section 9.5.1.3 invokes the fire hazard analysis which describes the wall between safety chiller trains as a 1-hour fire barrier. Contrary to this requirement, fire door E-1B, a normally closed door, which was part of the 1-hour fire barrier wall, was found partially open because the door did not latch. Specifically, on April 5, 2022, and again on June 10, 2022, the licensee negated the 1-hour rating of the barrier by failing to ensure that fire door E-1B was closed and latched.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Main Feedwater Pump Trip Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05000445/2022002-02 Open/Closed
[H.1] -
Resources 71111.12 The inspectors reviewed a self-revealed Green finding when the licensee failed to assemble main feedwater pump 1-01 turbine casing in accordance with manufacturer drawings.
Specifically, General Electric drawing 125D431EC includes tolerances for gaps between seal components and forms part of the design bases for the facilities; however, the tolerances were not followed. Because of these out of specification tolerances steam/moisture entered the lube oil system, resulting in internal corrosion and degradation that caused an automatic trip of main feedwater pump 1-01.
Description:
During a planned Unit 1 shutdown for refueling outage 1RF21, the Unit 1 main feedwater pump 1-01 failed to trip. As part pf the investigation, the licensee inspected the oil sump and the hydraulic controls. These inspections revealed water in-leakage into the oil system. Since the system was not designed for water, corrosion occurred on system components after the oil filter. Corrosion products mobilized and reached valves in the control portion of the system. Specifically, the hydraulic trip relay and the hydraulic bypass relay were internally bound due to corrosion and debris from the contaminated oil system. During refueling outage 1RF21, the licensee cleaned the system and replaced degraded components. Engineering personnel attributed the water leakage to a degraded controller for the pump seal system.
On March 29, 2021, a Unit 1 automatic runback from 100 to 60 percent reactor power occurred due to the Unit 1 main feedwater pump 1-01 automatically tripping unexpectedly.
The only precursor to the trip was slight speed oscillations on the Unit 1 main feedwater pump 1-01. With the pump shutdown, the licensee inspected the control oil system and again noted corrosion products. Initially, the licensee believed that the controller for the pump seal system was causing water in-leakage to the control oil system. After correcting the as found condition, the licensee recovered the pump and ascended to 100 percent power. During subsequent inspections, the licensee noted, steam leaks from the turbine casing were identified and documented.
At this time, the inspectors noted a sump drain capability that would drain accumulated water from the system. When the inspectors asked the licensee about this capability, the licensee drained approximately 7 gallons of water from the sump. Since the seal controller issue had been corrected, the licensee concluded that the turbine casing steam leak was the source of the water. The licensee initiated interim action to mitigate the effects of the leak until the next scheduled outage. These actions included weekly draining of the water from the lube oil sump; installing fans to limit the steam leak plume concentration; writing an adverse condition monitoring plan; installing an additional filter unit; and more frequent main turbine oil filtration skid and centrifuge alignments. The licensee also planned to partially disassemble the turbine to identify and correct the cause of the steam leakage.
During the planned refueling outage in April 2022, the licensee examined the turbine casing shaft seal to determine the cause of the steam leak. During the inspection, the licensee noted that internal clearances exceeded tolerances specified in the vendor manual. In reviewing the cause of the excessive clearances, the licensee noted that the seals were assembled without-of-tolerance butt joints during the last refueling outage 1RF21. The inspectors reviewed work order (WO) 5512146 and noted that the WO did not include tolerances for butt gaps. The inspection in refueling outage 1RF22 also revealed that the No. 12 packing was missing springs. Since the licensee did not rebuild this packing during refueling outage 1RF21, workmanship issues existed prior to refueling outage 1RF21.
The inspectors noted that the licensee contracted with a vendor to perform the turbine rebuilding work. During the work, the vendor took post work butt clearances, but the vendor failed to inform the site of unsatisfactory post work measurements. In reviewing the work order, the inspectors noted that the step 8.4.6 of MSM-CO-4100, revision 1 was used by the vendor to reinstall shaft seals that were previously removed. That step has no direct reference to the General Electric drawing 125D431EC for butt gap clearances or procedural criteria.
The inspectors inquired as to how drawing information was communicated to the workers and were informed that the field engineer had the drawings and vendor information available; however, nothing in the work order required the workers to ensure butt gap tolerances.
Corrective Actions: The licensee rebuilt feedwater pump 1-01 turbine casing to appropriate casing allowances during the April 2022 refueling outage. They also reperformed a causal evaluation performed in 2021 to include new information obtained during the rebuild. Planned corrective actions include evaluating the work instructions to add additional detail to include dimensional tolerance acceptance criteria while performing a casing rebuild. The subsequent startup of the main feedwater pump turbine and sump oil samples identified that the steam leak was corrected, and no excessive amount of water was being introduced to the lube oil sump.
Corrective Action References: Comanche Peak added entered these issues into the corrective action program with condition reports (CR) 2020-007334, 2021-002216, 2020-008521, and 2022-003679.
Performance Assessment:
Performance Deficiency: The failure to assemble the feedwater pump turbine casing in accordance with manufacturer drawings is a performance deficiency. Specifically, General Electric drawing 125D431EC includes tolerances for gaps between seal components and forms part of the design bases for the facilities. These clearances establish a seal configuration to limit steam leaks past the shaft seal. Comanche Peak accepted General Electric drawing 125D431EC into the vendor control program per section 3.1.6 of ECE-501, Engineering Change Evaluation.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance 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, the corrosion that occurred caused internal component degradation which affected the reliability of the MFP. The corrosion caused an unplanned automatic trip of feedwater pump 1-01 and automatic plant runback to 60 percent power.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. In accordance with Section B of IMC 0609, Appendix A, Exhibit 1, Initiating Events Screening Questions, the finding is of Green Significance because the finding did not cause a reactor trip and a loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition.
Cross-Cutting Aspect: H.1 - Resources: Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety.
During the work activity, the licensee failed to ensure information related to seal tolerances in the form of work instruction details were available to workers.
Enforcement:
Inspectors did not identify a violation of regulatory requirements associated with this finding.
Condensate Storage Tank Level Inaccuracies.
Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000445,05000446/2022002-03 Open/Closed
[H.13] -
Consistent Process 71152A The inspectors identified a Green finding and associated violation of 10 CFR 50, Appendix B, Criterion XVI for the licensees failure to correct a condition adverse to quality. Specifically, the licensee identified in 2017 that level indication of the CST was adversely influenced by nitrogen overpressure resulting in non-conservative level indications. The licensee did not correct the condition until 2022 following inspector inquiries on the 2017 condition report.
Description:
In 2017, the licensee recognized that nitrogen overpressure in the CST resulted in a bias to the level indication that overstated CST volume. The licensee identified that the bladder had come in contact with the top of the CST. At the time, the licensee measured the pressure in the gas space of the CST as 0.49 psig. The calculations supporting CST inventory did not include the pressure as a constant bias and the over pressure resulted in high readings of CST level. Condition report (CR) 2017-10346 evaluated the condition and recommended maintaining CST level at 58 percent to ensure adequate inventory. The Technical Specification (TS) 3.7.6 limit was 53 percent with the TS bases specifying the value as measured at the control board. This level would ensure 244,000 gallons of available volume. To ensure adequate inventory, the CR discussed the magnitude of the error and concluded that the bias creates a 1.69 percent error in CST level indication with 1/3 psig overpressure bounding value as stated in the design bases document. This equated to 9071 gallons. Calculation ME(B)-240 analyzed CST level to validate TS limits can supply the required volume of water. The calculation stated that TS 3.7.6 had a margin of 3840 gallons; therefore, the error created by 1/3 psig resulted in an insufficient inventory by 5231 gallons.
This error indicated the current TS limits were non-conservative and should be addressed.
Although the licensee documented the condition, immediate corrective actions were limited to administrative controls to ensure level in the CST remained above 244,000 gallons needed to support the accident analysis and to prevent overfilling of the CST. Between 2017 and 2021, the licensee pursued identification of level indicators that could account for bias imposed by the overpressure. On July 29, 2021, the licensee concluded that a suitable level indication did not exist and closed the last action on the CR. The licensee did not pursue alternative resolutions to the CST level error, e.g., a TS amendment or additional engineering analysis.
In November of 2021, the inspectors inquired regarding long-term resolution of the issue and why the licensee had not followed guidance for non-conservative TSs provided in Administrative Letter 98-10, Dispositioning of Technical Specifications that are Insufficient to Assure Plant Safety, and NEI 15-03[PD1], Licensee Actions to Address Nonconservative Technical Specifications. In response, the licensee re-evaluated the errors and determined the bias imparted by the overpressure was significantly less than previously evaluated - 0.5 inches of water column (-0.0180 psig). Assuming this error was bounding, the current TS level limit provided sufficient water inventory to meet accident assumptions. The licensee also informed the inspectors the larger magnitude errors occurred when the bladder became constrained, for example by contacting the top of the CST.
Corrective Actions: The licensee developed a new analysis that supported current TS limits.
Corrective Action References: CR 21-7446
Performance Assessment:
Performance Deficiency: The licensees failure to address the level inaccuracies identified in 2017 and documented in CR-2017-10346 was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control 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. The inspectors reviewed the examples in IMC 0612, Appendix E and concluded that examples 3.h and 3.i applied since the performance deficiency created reasonable doubt as to the capability of the CST. The performance deficiency resulted in the licensee revising the analysis to account for the weight of the bladder and overpressure on the CST inventory.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A. The inspectors determined that the licensees failure to correct the analysis supporting TS limits on CST level was a performance deficiency that warranted a significance evaluation. In accordance with Section B of IMC 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions, the inspectors determined the finding was of very low safety significance, Green, because it affected the design of the CST and the CST maintained operability.
Cross-Cutting Aspect: H.13 - Consistent Process: Individuals use a consistent, systematic approach to make decisions. Risk insights are incorporated as appropriate. The licensee failed to consider the risk associated with having a non-conservative TS and decided administrative controls were an appropriate action verses correcting the actual condition.
Enforcement:
Violation: Title 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, states, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected. Contrary to the above, the licensee failed to promptly correct a condition adverse to quality. Specifically, between September 19, 2017, and March 28, 2022, the licensee failed to promptly correct the condition of TS 3.7.6 minimum level requirement not being supported by calculation. In 2017, the licensee identified that nitrogen overpressure in the CST created a condition where meeting TS level limits would not ensure adequate inventory to support accident analysis. In March of 2022, the licensee completed an analysis demonstrating the acceptability of the current CST TS limits.
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 28, 2022, the inspectors presented the Unit 1 inservice inspection results to T.
McCool, Site Vice President, and other members of the licensee staff.
On April 28, 2022, the inspectors presented the occupational radiation safety inspection results to Mr. J. Dreyfuss, Director, Organizational Effectiveness, and other members of the licensee staff.
On June 23, 2022, the inspectors presented the emergency preparedness exercise scenario review inspection results to Mr. P. Allen, Manager, Emergency Preparedness, and other members of the licensee staff.
On July 13, 2022, the inspectors presented the integrated inspection results to Mr. J.
Dreyfess, Director, Organizational Effectiveness, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
FPI-301A
Unit 1 and 2 Turbine Building Elevation 778'-0"
FPI-302A
Unit 1 and 2 Turbine Building Elevation 803'-0"
FPI-303A
Unit 1 and 2 Turbine Building Elevation 830'-0"
Fire Plans
FPI-510
Electrical and Control Building Chiller Pump Rooms Elev.
778'-0"
FPI - 102A
Fire Preplan, Unit 1 Safeguards Building, Elevation 790
Procedures
FPI - 102B
Fire Preplan Unit 2 Safeguards Building Elevation 790
Calculations
GBH 2323A
Auxiliary Feedwater Pump Room Flooding
206
ME-CA-0000-
264
Safe Shutdown Impoundment Hydrothermal Analysis
Calculations
ME-CA-0000-
264
Safe Shutdown Impoundment Hydrothermal Analysis
Corrective Action
Documents
2004-001456, 2005-001362, 2009-000794, 2014-013573,
2017-010530, 2017-011968, 2019-004334, 2019-009039,
2019-009040, 2019-009041, 2019-009042, 2019-009043,
2019-009044, 2020-002581, 2020-003068, 2020-004812,
20-007762, 2020-007876, 2020-008354, 2020-008364,
20-008917, 2015-008353, 2015-008589, 2017-010530,
2017-011968
SG-CDMP-22-11
Comanche Peak 1RF22 Steam Generator Condition
Monitoring and Final Operational Assessment
Miscellaneous
TR-2019-006596
ISI Program Self Assessment
MDA-316
Control Of Load Handling
MDA-402
Control Of Load Handling Equipment
SG-SGMP-17-32
Comanche Peak Unit 1, 1 RF 19 Outage Steam Generator
Condition Monitoring and Cycles 20, 21, and 22 Operational
Assessment
11/01/2017
STA-612
System Cleanness Control and Cleaning
STA-729
Control Of Transient Combustibles, Ignition Sources and Fire
Watches
STA-737
Boric Acid Corrosion Detection and Evaluation
Procedures
STA-737.01
Boric Acid Corrosion Detection and Evaluation
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
TX-1S1-8
VT-1 and VT-3 Visual Examination Procedure
TX-ISI-11
Liquid Penetrant Examination for Comanche Peak Nuclear
Power Plant
TX-ISI-210
Ultrasonic Examination Procedure for Welds in Ferretic Steel
Vessels
TX-ISI-214
Ultrasonic Examination Procedure for Piping Systems and
Vessels
TX-ISI-301
Ultrasonic Examination Procedure for Welds in Ferretic
Piping Welds
TX-ISI-302
Ultrasonic Examination Procedure for Welds in Austenitic
Piping Welds
TX-ISI-70
Magnetic Particle Examination for Comanche Peak Nuclear
Power Plant
TX-ISI-IWE
Metal Containment Visual Examinations
TX-ISI-IWL
Concrete Structure Visual Examinations
WDI-STD-1007
Generic Procedure for the Ultrasonic Examination of Weld
Overlaid Similar and Dissimilar Metal Welds using PDI-UT-8
Maintenance Rule
Database
Unit 2 VAC - Containment Ventilation
06/30/2022
Miscellaneous
System Health
Report
Documents
System Health Executive Summary
CNPP System Status
FW System Status
2/09/2022
Corrective Action
Documents
AI-TR-2022-3421
Miscellaneous
IPTE Pre-Job Brief for Integrated Leak Rate Test
03/30/2022
Procedures
SOP-101A
Corrective Action
Documents
CR-YYYY-NNNN
2016-9220, 2018-2717
Miscellaneous
SORC 22-006
RF22 Startup SORC package.
05/05/2022
Engineering
Changes
FDA-2022-
000030-01
Temporary Modification on 1-HV-2321
Procedures
NDE 4.02
ASME XI Visual Examination VT-2
Corrective Action
Documents
Outage Mode restraint Report
05/08/2022
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Work Orders
5741770, 5859365, 5815602, 5850365, 4525990, 4662104,
4319185, 4643426
Corrective Action
Documents
CR-YYYY-NNNN
22-2904
NDE Reports
1RF22(I4)-VT-35
FB Transfer Canal Inspection
04/25/2022
Procedures
OPT-511A
FW Isolation Valve Testing
CPNPP GREEN Team Exercise
06/22/2022
Miscellaneous
Exercise Guide
06/22/2022
CPP-202200223
Comanche Peak Nuclear Power Plant (CNPP); Docket Nos.
50-445, 50-446, and 72074; Transmittal of the CPNPP
Biennial Emergency Preparedness Exercise Scenario
5/25/2022
CPSES-
200700115
Comanche Peak Steam Electric Station (CPSES), Docket
Nos. 50-445 and 50-446; Response Providing Information
Regarding Implementation Details for the Phase 2 & 3
Mitigation Strategies
1/22/2007
Miscellaneous
EPP-201, EAL
Tech Bases
Comanche Peak Nuclear Power Plant, EPP-201, Emergency
Action Level Technical Bases Document
ABN-909
Spent Fuel Pool/Refueling Cavity Malfunction
SAG-1.0
Control Room Severe Accident Initial Response
SAG-10.0
TSC Severe Accident Response Control SFP Level
Procedures
SOP-506
Spent Fuel Pool Cooling and Cleanup System
Corrective Action
Documents
Resulting from
Inspection
TR-YYYY-NNNN
22-003249
24-APR-2022-
0005
Gamma Spectrum Analysis - SG Air Sample
04/22/2022
M-20220410-19
U1 RB 808' Trashrack 1-154 A/D
04/10/2022
M-20220422-33
U-1 RB 825' S/G Platform #4
04/22/2022
M-20220422-36
U-1 RB 825' S/G Platform #1
04/22/2022
M-20220422-37
Airborne Radioactivity Survey
Map 1 through Map 6
04/22/2022
M-20220424-10
U-1 RB 825' S/G Platform #4
04/24/2022
Radiation
Surveys
M-20220424-41
U-1 RB 872' RX Head on Stand
04/24/2022
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
M-20220424-6
U-1 RB 825' S/G Platform #1
04/24/2022
M-20220424-8
U-1 RB 825' S/G Platform #3
04/24/2022
M-20220425-23
Survey S/G 1/ 4 Loop room and platform
04/25/2022
M-20220425-3
U-1 RB 872' RX Head on Stand
04/24/2022
M-20220425-41
U-1 RB 872' RX Head on Stand
04/25/2022
M-20220426-4
U-1 RB 825' S/G Platform #3
04/26/2022
M-20220426-5
Airborne Radioactivity Survey
Map 2 and Map 3
04/26/2022
M-20220426-69
U-1 RB 812' Loops 2 and 3
04/25/2022
M-20220427-1
U-1 RB 808' Valve replacement 1-8708A
04/26/2022
RWP 20221211
1RF22 Activities Unit 1 Containment 808' Corridors Rooms
1-154 A/B/C/D/H
RWP 20221400
1RF22 Westinghouse Primary Side Steam Generator
Activities
Radiation Work
Permits (RWPs)
RWP 20221404
1RF22 ISI, FAC and associated activities to include PZR
Heater
IR-
22-003253
Corrective Action
Documents
Resulting from
Inspection
TR-YYYY-NNNN
22-003255
IC(B)097
Instrument Uncertainties and Indicator Loop Accuracy for
CST Level Instrumentation Loops 1-LI-2478A and 1-LI-
2579A
ME(B)-240
Condensate Storage Tanks Technical Specification Limit
Calculations
MEB-172
Condensate Storage tank -Determination of Critical Depth for
Vortex Flow and Usable Tank Volume
CR-YYYY-NNNN
2017-10280, 2017-10346, 2021-7446
71152A
Corrective Action
Documents
TR-2021-7314