IR 05000373/2021001
| ML21124A147 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 05/04/2021 |
| From: | Kenneth Riemer NRC/RGN-III |
| To: | Rhoades D Exelon Generation Co |
| References | |
| IR 2021001 | |
| Download: ML21124A147 (24) | |
Text
May 4, 2021
SUBJECT:
LASALLE COUNTY STATION - INTEGRATED INSPECTION REPORT 05000373/2021001 AND 05000374/2021001
Dear Mr. Rhoades:
On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at LaSalle County Station. On April 14, 2021, the NRC inspectors discussed the results of this inspection with Mr. J. Washko, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Two 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 III; the Director, Office of Enforcement; and the NRC Resident Inspector at LaSalle County Station.
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 III; and the NRC Resident Inspector at LaSalle County Station. 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/
Kenneth R. Riemer, Chief Branch 1 Division of Reactor Projects
Docket Nos. 05000373 and 05000374 License Nos. NPF-11 and NPF-18
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000373 and 05000374
License Numbers:
Report Numbers:
05000373/2021001 and 05000374/2021001
Enterprise Identifier: I-2021-001-0038
Licensee:
Exelon Generation Company, LLC
Facility:
LaSalle County Station
Location:
Marseilles, IL
Inspection Dates:
January 1, 2021 to March 31, 2021
Inspectors:
J. Bozga, Senior Reactor Inspector
G. Edwards, Health Physicist
R. Elliott, Resident Inspector
E. Fernandez, Reactor Inspector
J. Havertape, Reliability and Risk Analyst
M. Holmberg, Senior Reactor Inspector
W. Schaup, Senior Resident Inspector
L. Torres, Illinois Emergency Management Agency
R. Zuffa, Illinois Emergency Management Agency
Approved By:
Kenneth R. Riemer, Chief
Branch 1
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at LaSalle County Station, 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 Ensure Seismic Category II over Category I Requirements Met for Control Room Lighting Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000373,05000374/2021001-01 Open/Closed None (NPP)71111.15 The inspectors identified a Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, "Design Control," for the licensee's failure to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. Specifically, the licensee failed to secure the control room lighting louvers to ensure they would not fall during a seismic event impacting operators and safety-related or safe-shutdown equipment in the control room.
Unqualified Weld Procedure Applied for Repair of Reactor Coolant Pressure Boundary Material Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000373,05000374/2021001-02 Open/Closed
[H.9] - Training 71111.18 The inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion IX, Control of Special Processes, for the licensees failure to control an essential welding variable (base metal thickness) and apply a qualified weld procedure specification (WPS) for repair of the 2B33-F060A/B valve bodies which are part of the reactor coolant pressure boundary. Specifically, the licensee's WPS 8-8-GT-2,
Revision 2 lacked weld metal tests to qualify the procedure for weld repair of the 2B33-F060A/B valve bodies necessary to ensure the mechanical properties of the repair were adequate to support the pressure retaining safety function.
Additional Tracking Items
None.
PLANT STATUS
Unit 1 began the inspection period at rated thermal power. On March 30, 2021, the unit was down powered to approximately 85 percent due to 'A' condensate polisher adverse trend in flow.
The condensate polisher was removed from service and troubleshooting was commenced.
After establishing the correct operating parameters for the condensate polisher, the polisher was returned to service. The unit was returned to rated thermal power the following day. The unit remained at or near rated thermal power for the remainder of the inspection period.
Unit 2 began the inspection period in coast down to Refueling Outage (RO) L2R18. On February 21, 2021, Unit 2 was shut down to commence RO L2R18. The unit remained in the refueling outage 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 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 onsite 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.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Impending Severe Weather Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather (snowstorms) on January 25 and 26, 2021.
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 2B residual heat removal on February 17, 2021
- (2) Unit 1 Division 2 diesel generator on February 26, 2021
- (3) Unit 2 Division 2 diesel generator on March 1, 2021
- (4) Unit 2 high pressure core spray on March 8, 2021
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
- (1) Fire Zone 3H1, Unit 2 reactor building, elevation 694', 'A' residual heat removal emergency core cooling system (ECCS) room cooler and reactor core isolation cooling (RCIC)/low pressure core spray (LPCS) ECCS room cooler on February 24, 2021
- (2) Fire Zone 3l1, Unit 2 reactor building, elevation 673', Division 1 core standby cooling system lake return, line 2RH83D-24 on February 24, 2021
- (3) Fire Zone 2H2, Unit 2 reactor building, elevation 673' to 844', drywell on March 8, 2021
- (4) Fire Zone 3J, Unit 1 reactor building, elevation 694', high pressure core spray on March 8, 2021
71111.08G - Inservice Inspection Activities (BWR)
BWR Inservice Inspection Activities Sample - Nondestructive Examination and Welding
Activities (IP Section 03.01)
- (1) The inspectors verified that the reactor coolant system boundary, reactor vessel internals, risk-significant piping system boundaries, and containment boundary were appropriately monitored for degradation and that repairs and replacements were appropriately fabricated, examined and accepted by reviewing documents of the following activities from February 22, 2021 to March 9, 2021:
03.01.a - Nondestructive Examination and Welding Activities
1. ultrasonic examination of feedwater nozzle to reactor pressure vessel weld,
LCS-2-N4A
2. ultrasonic examination of reactor recirculation pipe to sweepolet weld,
IRR-2003-18
3. ultrasonic examination of feedwater safe end to nozzle dissimilar metal weld,
IFW-2001-20A
4. visual examination (VT-3) of residual heat removal snubbers, 2RH18-2809S
and 2RH18-2810S
5. visual examination (VT-3) of reactor recirculation flow control valve
6. visual examination (VT-1) of reactor recirculation flow control valve
2B33-F060B-4 body nuts, washers, bushing, and pressure retaining bolting
7. visual examination (VT-1) of reactor recirculation flow control valve
2B33-F060B-3 bonnet cover nuts, washers, bushing, and pressure retaining bolting
8. 2B reactor recirculation pump lug 2B33-C001B indication evaluation
9. replacement of 2FW11AA-4", 2FW11AB-4" and 2RT06A-4" piping
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 reactor plant shutdown on Unit 2 for RO L2R18 on February 21 and 22, 2021, and reactor plant cooldown on February 22 and 23, 2021.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated risk-informed completion training on January 20, 2021, and just-in-time training for reactor plant shutdown to support the upcoming RO L2R18.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (1 Sample)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
- (1) Unit 2 Division 3 diesel generator heat exchanger
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) Unit 2 standby liquid control system squib valves after testing and replacement during RO L2R18
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (6 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 2 emergent work on the Division 3 diesel generator due to a fuel oil and service water leak on February 18, 2021
- (2) Unit 2 shutdown safety Yellow due to reduced inventory while filling the reactor cavity on February 23, 2021
- (3) Units 1 and 2 protected pathways for the Division 1 core standby cooling system modification license amendment window beginning on February 24, 2021
- (4) Unit 1 online risk Yellow due to Division 1 diesel generator cooling water system unavailable for maintenance on February 26, 2021
- (5) Unit 2 shutdown safety Yellow due to Division 1 safety bus, 241Y, maintenance unavailability window on February 28, 2021
- (6) Unit 1 online risk Yellow due to Division 1 safety bus, 241Y, maintenance unavailability window on March 1, 2021
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (3 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) Action Request 4403134, "Diesel Generator Coolant Leak on 2B (Division 3) Diesel Generator Heat Exchanger (Service Water Side)"
- (2) Action Request 4403135, "2B (Division 3) Diesel Generator Fuel Leak"
- (3) Action Request 4365722, "Main Control Room Light Diffuser Fell"
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (3 Samples)
The inspectors evaluated the following temporary or permanent modifications:
- (1) Engineering Change 633318, "Alternate Reactor Recirculation Seal Staging Path for 1B Reactor Recirculation Pump"
- (2) Engineering Change 633674, Construction of Lower Guide Support for 2B33-F060A/B
- (3) Engineering Change 633664, ASME Section XI Repair Plan for Valve 2B33-F060B, Associated with Restoring the Valve to Full Qualification
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (8 Samples)
The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:
- (1) Unit 2 Division 3 diesel generator after repairs to the fuel system and cooling system on February 18, 2021
- (2) Unit 2 emergency core cooling room cooler 2VY04A room cooler after replacement on March 4, 2021, per Work Order 4677540
- (3) Unit Common Division 1 diesel generator room cooler after replacement of the Unit 2 Division 1 ECCS room coolers on March 4, 2021
- (4) Unit 2 emergency core cooling room cooler 2VY01A room cooler after cooler replacement on March 5, 2021, per Work Order 4677533
- (5) Unit 2 LPCS system on March 6, 2021, per Work Order 4902887
- (6) Unit 2 standby liquid control system on March 7, 2021, per Work Orders 4923222,
===4896583, and 4896585
- (7) Unit Common Division 1 diesel generator after comprehensive maintenance during RO L2R18 on March 8, 2021
- (8) Unit 2 reactor water cleanup inboard primary containment isolation valve breaker on March 15, 2021, per Work Order 4902882
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) LOS-DG-201, common diesel generator 0DG01K start and load acceptance surveillance on March 3, 2021, per Work Order 4610024
- (2) LOS-DG-209, Unit 2 integrated Division 1 response time surveillance on March 6, 2021, per Work Order 4612242
Containment Isolation Valve Testing (IP Section 03.01)===
- (1) LST-100-3, main steam isolation valve local leak rate tests on February 22,
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)
The inspectors evaluated instructions to workers including radiation work permits used to access high radiation areas.
- (1) The inspectors evaluated instructions to workers including radiation work permits used to access high radiation areas and labeling of radioactive material in containers.
Contamination and Radioactive Material Control (IP Section 03.03) (3 Samples)
The inspectors evaluated licensee processes for monitoring and controlling contamination and radioactive material.
- (1) The inspectors observed workers exiting the radiological controlled area at Unit 2 during a refueling outage.
- (2) The inspectors observed licensee surveys of potentially contaminated material leaving the radiological controlled area.
- (3) The inspectors observed work area staging for inspection/repairs of the A/B 60' flow control valves.
Radiological Hazards Control and Work Coverage (IP Section 03.04) (3 Samples)
The inspectors evaluated in-plant radiological conditions during facility walkdowns and observation of radiological work activities.
- (1) The inspectors observed 2B33-FO60A/B valve repairs/inspections during the spring 2021 outage (Radiation Work Permit LA-02-21-00549 and associated as-low-as-reasonably-achievable (ALARA) documentation).
- (2) The inspectors observed drywell control rod drive (CRD) exchange during the spring 2021 outage (Radiation Work Permit LA-02-21-00513 and associated ALARA documentation).
- (3) The inspectors observed reactor building valve work during the spring 2021 outage (Radiation Work Permit LA-02-21-00622 and associated ALARA documentation).
High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (3 Samples)
The inspectors evaluated licensee controls of the following high radiation areas and very high radiation areas:
(1)reactor building 673' residual heat removal 'A' corner room
- (2) Unit 2 drywell 740/760' general area (3)reactor building refuel floor
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.
71124.02 - Occupational ALARA Planning and Controls
Implementation of ALARA and Radiological Work Controls (IP Section 03.03) (3 Samples)
The inspectors reviewed ALARA practices and radiological work controls.
- (1) The inspectors evaluated items associated with Radiation Work Permit LA-02-21-00549 and associated ALARA documentation for L2R218 2B33-FO60A/B valve repairs/inspections during the spring 2021 outage.
- (2) The inspectors evaluated items associated with Radiation Work Permit LA-02-21-00601 and associated ALARA documentation for L2R218 reactor building reactor water cleanup system maintenance during the spring 2021 outage.
- (3) The inspectors evaluated items associated with Radiation Work Permit LA-02-21-00513 and associated ALARA documentation for L2R218 drywell CRD exchange during the spring 2021 outage.
Radiation Worker Performance (IP Section 03.04) (1 Sample)
The inspectors evaluated radiation worker and radiation protection technician performance during:
- (1) The inspector evaluated radiation worker and radiation protection technician performance during flow control valve 60 'A' and 'B' repairs.
71124.03 - In-Plant Airborne Radioactivity Control and Mitigation
Temporary Ventilation Systems (IP Section 03.02) (1 Sample)
The inspectors evaluated the configuration of the following temporary ventilation systems:
(1)temporary HEPA filtration units on the Unit 2 refuel floor
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 03.01)===
- (1) Unit 1 (January 1, 2020 to December 31, 2020)
- (2) Unit 2 (January 1, 2020 to December 31, 2020)
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 03.02) (2 Samples)
- (1) Unit 1 (January 1, 2020 to December 31, 2020)
- (2) Unit 2 (January 1, 2020 to December 31, 2020)
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 03.03) (2 Samples)
- (1) Unit 1 (January 1, 2020 to December 31, 2020)
- (2) Unit 2 (January 1, 2020 to December 31, 2020)
INSPECTION RESULTS
Failure to Ensure Seismic Category II over Category I Requirements Met for Control Room Lighting Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000373,05000374/2021001-01 Open/Closed
None (NPP)71111.15 The inspectors identified a Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, "Design Control," for the licensee's failure to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. Specifically, the licensee failed to secure the control room lighting louvers to ensure they would not fall during a seismic event impacting operators and safety-related or safe-shutdown equipment in the control room.
Description:
On August 26, 2020, a metal light louver in the southeast corner of the main control room fell to the floor for no known reason. The louver weighed approximately 10 pounds and had sharp edges. This area of the control room is not normally occupied; however, if the panel had fallen in an area normally occupied, it had the potential to injure personnel. The licensee documented the event in the corrective action process as Action Request 4365722. They took corrective actions for personnel safety and to reinstall the louver.
The inspectors toured the control room and noted that ceiling louvers directly over main control room panels had additional restraints in place to ensure the louvers would not fall during a seismic event, but all remaining ceiling louvers were lying in the grid without additional restraints to prevent them from falling during a seismic event. The inspectors discussed their findings with the shift manager and questioned why the remaining louvers were not restrained for a seismic event which had the potential to have the louvers fall on personnel or come in contact with the control panels. The licensee documented the issue in the corrective action process as Action Request 4367534.
The inspectors requested the documents and procedures that were used to install the louvers in the main control room. In 2017 the licensee wrote Engineering Change (EC) 618680 to upgrade the fluorescent normal and AC essential lighting in the main control room with LED style lamps and replace the existing ceiling louver panels with replacement white ceiling louver panels. The design attribute review identified that there were seismic considerations with the change. These were discussed in Section 4.1.4.3 of the engineering change, stating that the design change was classified as a Seismic Category II/I as the lighting fixtures and ceiling louver panels are seismically mounted in areas where their failure could cause damage to safety-related equipment. Installation details, Section step 9, stated, "Louver panels will be secured to the grid using zip/cable ties.
The inspectors also noted that Section 4.1.38, "Civil/Structural Requirements," of EC 618680, stated that the lighting fixtures are not required to be seismically qualified per the Updated Final Safety Evaluation Report (USFAR) Section 9.5.3 for LaSalle County Generating Station (LCGS). It also stated that in the LaSalle control room no speakers are installed on the louver; therefore, there are no seismic concerns. However, the louver panels will be secured to the louver grids so that it does not fall during a seismic event. The inspectors review of the USFAR identified the following:
The inspectors review of Section 9.5.3, "Design Requirements," noted that step d, states, in part, "The control room lighting systems are designed to prevent mechanical failure during design basis Seismic Class I conditions," and that step f, states, "Lighting fixtures are not seismically qualified. The structural supports are seismically qualified in areas where seismic equipment failure could cause injury to operating personnel or to safety-related equipment."
The inspectors reviewed Work Order 4665229 that installed the lighting and the louvers.
Task 22 of the work order installed the louvers and step 6.2.5 of the work package instructions stated, "Louver panels will be secured to the grid using zip/cable ties." However, a minor revision was made to the step by engineering changing the word "will" to "may" and the zip/cable ties were not installed.
The inspectors reviewed station procedure MA-AA-716-010, "Maintenance Planning,"
Revision 24, Attachment 1, "Example of Work Package Revision Guidelines." The inspectors reviewed the first part of the guidance that provided minor examples of minor work revision and determined that the change did not meet the criteria for a minor revision. The inspectors reviewed the second part of the guidance that stated, "If the answer to any of the following questions is a 'yes', then return the work package to maintenance planning or planning qualified individual to process a major revision." The inspectors determined that at least two of the questions should have been answered "yes."
Do the changes affect:
- technical requirements such as torque valves, acceptance criteria, etc? In this case, the work order would be changing the technical requirement to meet the intent of USFAR Section 9.5.3, step d, and as described in the engineering change step 4.1.38.
- the end result of the work on the component or system being repaired? The change resulted in a different configuration than what was described in the engineering change (e.g. the louver was not secured to the grid).
The inspectors determined that the licensee should have either installed the zip/cable ties in accordance with Engineering Change 618680 or provided adequate justification or an evaluation to change the design as stated in Updated Final Safety Analysis Report (UFSAR)
Section 9.5.3 step
d. Corrective Actions:
Work Order 5077334 was completed on March 25, 2021, installing the required zip ties.
Corrective Action References: Action Requests 4365722 and 4367534
Performance Assessment:
Performance Deficiency: The inspectors determined that the licensee failed to ensure structural supports were seismically qualified in areas where seismic equipment failure could cause injury to operating personnel or to safety-related equipment as required by the LCGS USFAR Section 9.5.3.1 and was a performance deficiency. Specifically, the licensee did not seismically mount the control room louver panels in areas where their failure could cause injury to operating personnel or damage control room panels.
Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, during a design basis seismic event the unsecured louvers could fall, injuring control room personnel or potentially damage control room equipment that would challenge the safe shutdown of the plant.
Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors screened the issue against the Mitigating Systems questions and determined that the finding was of very low safety significance (Green) since the finding did not represent the loss or degradation of equipment or function specifically designed to mitigate a seismic event.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions.
LCGS UFSAR Section 9.5.3.1, Design Bases d, states, in part, "The control room lighting systems are designed to prevent mechanical failure during design basis Seismic Class I conditions."
LCGS USFAR Section 9.5.3.1, Design Bases f, states, in part "The structural supports are seismically qualified in areas where seismic equipment failure could cause injury to operating personnel or to safety-related equipment."
Contrary to the above, on October 27, 2017, the licensee failed to ensure that applicable regulatory requirements and the design basis were correctly translated into specifications, drawings, procedures, and instructions. Specifically, USFAR Section 9.5.3.1, step d stated that the control room lighting systems were designed to prevent mechanical failure during design basis Seismic Class I conditions. Engineering Change 618680 contained instructions to install zip/cable ties to the louvers to ensure they would not fall during a seismic event; however, the work order instructions were changed contrary to the engineering change and did not install the zip/cable ties, leaving the potential for the louvers to fall during a seismic event impacting operators and safety-related or safe-shutdown equipment in the control room.
Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.
Unqualified Weld Procedure Applied for Repair of Reactor Coolant Pressure Boundary Material Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events
Green NCV 05000373,05000374/2021001-02 Open/Closed
[H.9] - Training 71111.18 The inspectors identified a Green finding and associated NCV of 10 CFR Part 50, Appendix B, Criterion IX, Control of Special Processes, for the licensees failure to control an essential welding variable (base metal thickness) and apply a qualified WPS for repair of the 2B33-F060A/B valve bodies which are part of the reactor coolant pressure boundary.
Specifically, the licensee's WPS 8-8-GT-2, Revision 2 lacked weld metal tests to qualify the procedure for weld repair of the 2B33-F060A/B valve bodies necessary to ensure the mechanical properties of the repair were adequate to support the pressure retaining safety function.
Description:
In 2019 the licensee discovered foreign material in several jet pumps. After troubleshooting concluded, the debris was likely from the Unit 2 reactor recirculation flow control valve (2B33-F060A/B) internals. Valves 2B33-F060A/B are ball valves with cast bodies fabricated from American Society of Mechanical Engineers (ASME) SA-351 Grade CF8M material and have a safety-related pressure retaining function because the valve body forms part of the reactor coolant pressure boundary. These valve bodies were originally designed and constructed in accordance with the ASME Code,Section III, Subsection NB for Class 1 Components, 1971 Edition with Summer 1972 Addenda.
During the 2021 Unit 2 outage, after disassembly of valves 2B33-F060A and 2B33-F060B, the licensee identified damage to each of these valve's internals and at the bottom of the cast valve body that supports the shaft bearing. Specifically, the licensee reported "physical damage" on the inside surface of the pressure retaining boundary of the valve body caused by contact and repeated movement between the dislodged lower plug guide and the valve body. The licensee was unable to directly measure the amount of material lost from the 2B33-F060A/B valve bodies, but with the use of a contour gauge, estimated that approximately 0.75 inch of valve body wall thickness was lost. In preparation for welded repairs, the licensee machined/removed additional material from the inside surface of each valve body, which resulted in a pre-repair wall thickness slightly below the minimum design wall thickness of 2.4 inches. To restore the valves to an acceptable condition, the licensee elected to perform a weld buildup repair of the degraded valve bodies in accordance with the ASME Section III and ASME Section XI Code requirements.
The inspectors reviewed Engineering Change 633664 "ASME Section XI Repair Plan for Valve 2B33-F060B, Associated with Restoring the Valve to Full Qualification," and supporting licensee records associated with weld repair of the 2B33-F060B valve body, to determine if the repair complied with the applicable ASME Codes, as modified by the licensees letter to the NRC dated March 9, 2021, Relief Request I4R-12 Relief from Code Examinations for 2B33-F060A and 2B33-F060B Repairs. Specifically, the licensee identified in NRC-approved Relief Request I4R-12, that a weld buildup repair of the valve body would be accomplished with a gas tungsten arc welding (GTAW) process in accordance with the ASME Code Section III, paragraph NB-2539 to restore the valve body wall thickness. The ASME Code Section III, paragraph NB-2539.2, Qualification of Welding Procedures and Welders, stated The welding procedure and welders or welding operators shall be qualified in accordance with NB-4000 and Section IX of this Code, (see NB-2600). The ASME Code Section IX Qualification Standard for Welding and Brazing Procedures, Welders, Brazers, and Welding and Brazing Operators, Table QW-256 identified the GTAW process variables required to be maintained within specific ranges based on weld metal tests (e.g. tension, bend or impact tests) that demonstrate the weld process produced a weld with adequate mechanical properties to qualify the WPS. Included in Table QW-256 as an essential weld process variable was a limit for the qualified range of base metal thickness based on the thickness of test coupons used to qualify the GTAW procedure.
The licensee utilized a GTAW machine to deposit multiple passes of weld material to build up and restore the 2B33-F060A/B valve body thickness in accordance with WPS 8-8-GT-2 Revision 2, and this procedure was qualified to fabricate groove welds on base metals up to 1.7 inches thick (maximum) or fillet welds on any thickness of base metal. The 2B33-F060A/B valve body thickness (e.g. base metal) ranged up to approximately 4 inches thick, which exceeded the qualified range (1.7 inch maximum) in WPS 8-8-GT-2 for a groove weld, and thus was not qualified to fabricate a groove-type weld repair on these valves. The ASME Code Section IX Qualification Standard for Welding and Brazing Procedures, Welders, Brazers, and Welding and Brazing Operators, provided guidance for the type of weld (groove or fillet) applicable to the licensees weld repair. Specifically, paragraph QG-109.2 defined a fillet weld: a weld of approximately triangular cross section joining two surfaces approximately at right angles to each other in a lap joint, tee joint, or corner joint, and defined groove weld: a weld made in a groove formed within a single member or in the groove between two members to be joined. Based upon these definitions, the weld buildup deposit repair on the 2B33-F060A/B valve bodies was consistent with a groove weld but was not consistent with the definition of a fillet weld because this repair did not join two surfaces at approximately right angles. Therefore, the inspectors determined that the weld buildup deposits on the 2B33-F060A/B valve bodies were groove welds for the purposes of WPS qualification. Because the licensees procedure qualification records (PQRs) that supported WPS 8-8-GT-2 did not include a sufficiently thick base metal weld coupon (and tests) necessary to qualify the base metal essential variable to apply for the thickness of the 2B33-F060A/B valve bodies, this WPS was not qualified in accordance with the ASME Code Section IX for these weld repairs.
Corrective Actions: The inspectors concern prompted the licensee to revise WPS 8-8-GT-2 and incorporate additional weld metal tests conducted on thicker base metal samples as documented in PQR 4-51A. The additional tests recorded in this PQR demonstrated that WPS 8-8-GT-2 was qualified to deposit groove weld type repairs on base metal of sufficient thickness to bound the 2B33-F060A/B valve body repairs. Based on this corrective action, the inspectors did not have concerns for the structural integrity of the 2B33-F060A/B valve body repairs. The licensee entered this issue into the corrective action program.
Corrective Action References: Action Request 4409413
Performance Assessment:
Performance Deficiency: The inspectors determined that the licensee's failure to control an essential welding variable (base metal thickness) and apply a qualified WPS for repair of the 2B33-F060A/B valve bodies was contrary to 10 CFR 50, Appendix B, Criterion IX, Control of Special Processes, and a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, the failure to control an essential welding variable and apply a qualified WPS for repair of the 2B33-F060A/B valve bodies could have resulted in degraded mechanical properties that reduced the structural integrity of the reactor coolant pressure boundary and increased the risk for a loss of coolant accident (LOCA).
Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Specifically, the inspectors determined this finding affected the Initiating Events Cornerstone, but did not result in exceeding the reactor coolant system leak rate for a small LOCA and would not have effected other systems used to mitigate a LOCA. Therefore, the finding screened to very low safety significance (Green).
Cross-Cutting Aspect: H.9 - Training: The organization provides training and ensures knowledge transfer to maintain a knowledgeable, technically competent workforce and instill nuclear safety values. Specifically, the licensees site and corporate welding managers incorrectly determined that the weld repair of the 2B33-F060A/B valve bodies was a fillet weld instead of a groove weld for WPS qualification which indicated a lack of technical knowledge and/or competency necessary to instill nuclear safety values.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion IX, "Control of Special Processes,"
required "Measures shall be established to assure that special processes, including welding, heat treating, and nondestructive testing, are controlled and accomplished by qualified personnel using qualified procedures in accordance with applicable codes, standards, specifications, criteria, and other special requirements."
Contrary to the above, from March 10, 2021 through March 18, 2021, measures were not established to assure that a special process (welded repair of 2B33-F060A/B valve bodies, Work Orders 4691305-51 and 4697590-59) was controlled and accomplished using a weld procedure qualified in accordance with the applicable ASME Code Section IX. Specifically, the licensee applied weld metal on the 2B33-F060A/B valve bodies with procedure WPS 8-8-GT-2, Revision 2 which was not qualified for welding on this material because it exceeded the qualified base metal thickness limit (e.g. 1.7-inch maximum).
Enforcement Action: This violation is being treated as an NCV, 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 14, 2021, the inspectors presented the integrated inspection results to Mr. J. Washko, Site Vice President, and other members of the licensee staff.
- On March 9, 2021, the inspectors presented the inservice inspection results to Mr. J. Washko, Site Vice President, and other members of the licensee staff.
- On March 11, 2021, the inspectors presented the radiation protection inspection results to Mr. C. Smith, Site Operations Director, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
LAP-100-44
Inclement Weather Guidance
LOA-FSG-012
Flex Deployment Path Debris Removal
LOA-TORN-001
High Winds/Tornado
OP-AA-118-111-
1001
Severe Weather Guidelines and Natural Disasters
Drawings
M-141
P&1D High Pressure Core Spray (HPCS)
Procedures
LOP-HP-02E
Unit 2 High Pressure Core Spray Electrical Checklist
LOP-HP-02M
Unit 2 High Pressure Core Spray Mechanical Checklist
LOS-HP-Q4
High Pressure Core Spay System Operability Test
Fire Plans
FZ 2H2
Reactor Building 694'-6" Elevation, Unit 1 High Pressure
Core Spray Cubicle
FZ 3I2
Reactor Building 673'-4" Elevation, Unit 2 High Pressure
Core Spray Cubicle
FZ 3J
Reactor Building 637'-4" to 843'-6" Elevation Unit 2 Primary
Containment
Procedures
Pre-Fire Plan Manual
71111.08G Corrective Action
Documents
Ultrasonic Indication in RPV Vert Weld LCS-2-BA
2/16/2017
2B33-F067A Did Not Fully Close
2/22/2021
FME: Unknown FME Identified in Jet Pump Nozzle
2/24/2021
FME: Unknown FME Identified in Jet Pump Nozzle
2/24/2021
Actuator Overhaul of 2B33-F067A Needed in L2R19
2/25/2021
NDE VT-3 Recordable Indication in 2B33-F060B Valve Body
03/03/2021
ISI VT-1 Recordable Indication on 2B33-F060B Valve Body
Studs
03/02/2021
ISI VT-1 Recordable Indication on 2B33-F060B Valve
Bonnet Studs
03/02/2021
Corrective Action
Documents
Resulting from
Inspection
Unable to Retrieve 50.59 Eval Used for BER RI-ISI Program
2/24/2021
Miscellaneous
EPRI TR-
1006937
Extension of the EPRI Risk-Informed ISI Methodology to
Break Exclusion Region Programs
04/04/2002
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
VT-1 Visual Examination
Visual Examination of Component Supports, Attachments,
and Interiors of Reactor Vessels
VT-3 Visual Examination of Pump and Valve Internals
GEH-PDI-UT-2
PDI Generic Procedure for the Ultrasonic Examination of
Austenitic Pipe Welds
GEH-UT-254
Procedure for Automated Phased Array Ultrasonic
Examination of Dissimilar Metal Welds with the TOPAZ
GEH-UT-300
Procedure for Manual Examination of Reactor Vessel
Assembly Welds in Accordance with PDI
Work Orders
Replace Degraded Sections of 2FW11AA-4", 2FW11AB-4"
and 2RT06A-4"
08/17/2020
Engineering
Evaluations
Quality Receipt
Inspection
Package
Receipt# 239927, Catalog ID# 8175-1
07/15/2019
Procedures
LMP-SC-01
Standby Liquid Control Explosive Valve Maintenance
Work Orders
Squib Valve Replacement 2C41-F004A
07/14/2020
Corrective Action
Documents
Seismic Vulnerability Main Control Room
11/27/2012
Safety - Main Control Room Light Diffuser Fell
08/26/2020
Main Control Room Diffuser Fell, NRC Follow Up
09/04/2020
Diesel Generator Coolant Leak On 2B Emergency Diesel
Generator
2/18/2021
2B Diesel Generator Fuel Leak
2/18/2021
Engineering
Changes
Main Control Room LED Lighting Upgrade
Procedures
Maintenance Planning
Work Orders
Main Control Room LED Lighting and Ceiling Louver
Upgrade
03/17/2017
Corrective Action
Documents
ER-AA-335-014 Requires Revision
03/08/2021
Corrective Action
Documents
Resulting from
Inspection
NRC Questioned Weld Procedure Qualification
03/15/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Engineering
Changes
ASME Section XI Repair Plan for Valve 2B33-F060B,
Associated with Restoring the Valve to Full Qualification
Construction of Lower Guide Support for 2B33-F060A/B
Miscellaneous
WPS 8-8-GTSM
WPS 8-8-GT-2
WPS 8-8-GT-2
PQR 4-51A
09/12/1986
Welder DB1024, Certification Record
2/15/2021
Welder JM6422, Certification Record
03/08/2021
Welder CC7017, Certification Record
03/07/2021
Certified Material
Test Report
205AD941
Quaker Alloy Casting Co, ASME SA351-CF8M - 24 Valve
Body
08/16/1976
Certified Material
Test Report
2895
Consolidated Power Inc, ASME SA-479, Type 304L-1.5
Square Bar Stock
2/29/2020
Certified Material
Test Report
255097
ARCOS Industries LLC, - 400# - Type 316/316L Wire
07/01/2020
Exelon letter RS-
21-035
Relief Request I4R-12 Relief from Code Examinations for
2B33-F060A and 2B33-F060B Repairs
03/09/2021
NDE Reports
21-VT-019
2B33-F060B - Pre-Weld EVT1
03/14/2021
21-VT-024
2B33-F060A - 60A Weld Build Up EVT-1
03/28/2021
21-VT-025
2B33-F060B - 60B Weld Build Up EVT-1
03/28/2021
2B33-F060B - VT-3 of Internals
03/06/2021
Procedures
VT-1 Visual Examination
Work Orders
Repair 2833-F0608 Valve Body per EC 633664/633674
03/09/2021
Procedures
LOS-DG-M3,
2B-
IDLE
2B Diesel Generator Idle Start
105
LOS-DG-Q3,
B5
2B Diesel Generator Cooling Water Pump Inservice Test
LOS-DG-SR5
Diesel Generator Cooling Water System Flow Test
LOS-LP-Q3,
Unit 2 Low Pressure Core Spray Valve Inservice Test for
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2A
Cold Shutdown or Refuel Condition
LOS-LP-Q4,
2A
Unit 2 Low Pressure Core Spray System Operability Test
LOS-SC-Q1,
2A
Unit 2A Standby Liquid Control Pump and Motor Operated
Valve Operability/Inservice Test and Explosive Valve
Continuity Check
LOS-SC-Q1,
2B
Unit 2 B Standby Liquid Control and Motor Operated Valve
Operability/Inservice Test and Explosive Valve Continuity
Check
LOS-SC-R1,
2A
Unit 2 Standby Liquid Control Injection Test
LOS-SC-R5,
2A
Unit 2A Standby Liquid Control Pump Full Flow/Pressure
Test
LOS-SC-R5,
2B
Unit 2B Standby Liquid Control Pump Full Flow/Pressure
Test
LOS-VY-SR1,
A
Test A Residual Heat Removal Pump Room Area Cooler
Fan 2VY01C
LOS-VY-SR1,
D
Test Low Pressure Core Spray/Reactor Core Isolation
Cooling Pump Room Area Cooler Fan 2VY04C
Work Orders
Operations Post Maintenance Test - Verify Acceptable Air
Flow Through New Cooler
03/04/2021
Operations Post-Maintenance Test Division 1 Cooling Water
per LOS-DG-SR5
03/03/2021
Operations Post-Maintenance Test - Verify Acceptable Air
Flow Through New Cooler
03/04/2021
Reactor Water Clean Up Valve Post-Maintenance Tests
03/08/2021
Low Pressure Core Spray System Functional and Leak
Checks Post-Maintenance Tests
03/03/2021
Operations Post-Maintenance Test - Division 1 Cooling
Water Test per LOS-DG-SR5
03/03/2021
Operations Post-Maintenance Test 2B Diesel Generator
Cooling Water Heat Exchanger Leak Check
2/18/2021
Operations Post-Maintenance Test on 2E22-S001 Duplex
Strainer
2/18/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
LOS-DG-201
Diesel Generator 0DG01K Start and Load Acceptance
Surveillance
LOS-DG-209
Unit 2 Integrated Division 1 Response Time Surveillance
LTS-100-3
Main Steam Isolation Valve Local Leak Rate Test
2B21-F022A and 2B21-F028A
ALARA Plans
LA-02-21-00549
L2R218 2B33-FO60A/B Valve Repairs/Inspections
LA-02-21-00513
L2R18 Drywell Control Rod Drive (CRD) Exchange
Corrective Action
Documents
Unplanned Dose Rate Alarm
2/26/2021
Unanticipated Dose Rate Alarm in High Radiation Area
2/27/2021
Procedures
Radiological Risk Management
Radiation Work
Permits (RWPs)
LA-02-21-00549
L2R218 2B33-FO60A/B Valve Repairs/Inspections
LA-02-21-00513
L2R18 Drywell Control Rod Drive (CRD) Exchange
LA-02-21-00622
L2R218 Reactor Building Valve Work
Procedures
Administration of the Radiation Work Permit Program
Procedures
NISP-RP-008
Use and Control of HEPA Filtration and Vacuum Equipment
1