IR 05000454/2024003
| ML24312A378 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 11/12/2024 |
| From: | Richard Skokowski NRC/RGN-III/DORS/RPB3 |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| References | |
| IR 2024003 | |
| Download: ML24312A378 (1) | |
Text
SUBJECT:
BYRON STATION - INTEGRATED INSPECTION REPORT 05000454/2024003 AND 05000455/2024003
Dear David Rhoades:
On September 30, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Byron Station. On October 10, 2024, the NRC inspectors discussed the results of this inspection with H. Welt, 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 Byron 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 Byron Station.
November 12, 2024 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, Richard A. Skokowski, Chief Reactor Projects Branch 3 Division of Operating Reactor Safety Docket Nos. 05000454 and 05000455 License Nos. NPF-37 and NPF-66
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000454 and 05000455
License Numbers:
Report Numbers:
05000454/2024003 and 05000455/2024003
Enterprise Identifier:
I-2024-003-0055
Licensee:
Constellation Energy Generation, LLC
Facility:
Byron Station
Location:
Byron, IL
Inspection Dates:
July 01, 2024 to September 30, 2024
Inspectors:
N. Bolling, Resident Inspector
J. Cassidy, Senior Health Physicist
A. Demeter, Senior Resident Inspector
R. Elliott, Senior Project Engineer
R. Farmer, Health Physicist
J. Heimke, Project Engineer
T. Hooker, Health Physicist
R. Knutson, Illinois Emergency Management Agency (IEMA)
J. Park, Reactor Inspector
J. Robb, Operations Engineer
L. Torres, IEMA ASME Inspector
Approved By:
Richard A. Skokowski, Chief
Reactor Projects Branch 3
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Byron 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 Satisfy ASME Code Case N-722-1 Examination Requirements for Reactor Coolant System (RCS) Pressure Boundary Welds Cornerstone Significance Cross-Cutting Aspect Report Section Barrier Integrity Green NCV 05000454/2024003-01 Open/Closed
[H.7] -
Documentation 71111.08P The inspectors identified a finding of very low safety significance (Green) and an associated Non-Cited Violation (NCV) of 10 CFR Part 50, Section 50.55a(g)(6)(ii)(E), Augmented ISI requirements: Reactor coolant pressure boundary visual inspections, for the licensees failure to assure the ASME Code Case N-722-1 examination requirements for the Class I RCS instrument connection pressure boundary welds were satisfied. Specifically, during remote visual examination of the Reactor Pressure Vessel (RPV) bottom head, the licensee failed to complete examination of all nozzle-to-thimble guide tube welds as required by N-722-1.
Failure to establish a time-based preventative maintenance schedule for Diesel Generator Ventilation Fans Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000454,05000455/2024003-02 Open/Closed None (NPP)71111.12 A self-revealed finding of very low safety significance (Green) and associated non-cited violation of Technical Specification 5.4.1.a was identified for the licensees failure to establish an appropriate preventative maintenance (PM) schedule for the emergency diesel generator (EDG) ventilation fans. Specifically, time-based inspections including torque checks and other inspections to prevent excess movement of fan assembly components were not conducted on the ventilation fans despite being classified as a component needing this type of PM schedule.
The failure to establish an appropriate PM schedule resulted in the loosening of fan blade nuts going unnoticed nor corrected, increased stresses to the fan blades, and ultimately catastrophic failure of the 2A EDG ventilation fan.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000455/2022-001-01 LER 2022-001-01 for Byron Station, Unit 2, Volumetric Examinations of Reactor Pressure Vessel Head Core Exit Thermocouple 71153 Closed
Penetration P-75 Identified an Indication Attributed to Primary Water Stress Corrosion Cracking
PLANT STATUS
Unit 1 began the inspection period operating at full power. The unit entered power coast down on August 23, 2024. On September 9, 2024, Unit 1 was taken offline for a planned refueling outage. The unit remained offline and in the refueling outage for the remainder of the inspection period.
Unit 2 began the inspection period operating at full power and remained at or near full power for the entire inspection period.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors 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) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 1 safety injection system on July 9, 2024
- (2) Unit 1 residual heat removal system on July 17, 2024
- (3) Fuel pool cooling and cleanup system on July 31, 2024
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) Unit 2 auxiliary feedwater system ending September 27, 2024
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) Fire Zone 11.4-0, Auxiliary Building 383-0 Elevation General Areas - North, South, and West on July 2, 2024
- (2) Fire Zone 11.4A-0, Auxiliary Building 383-0 Elevation Control Room Refrigeration Equipment Room during 0A Control Room Chiller emergent maintenance on July 12, 2024
- (3) Fire Zone 3.2A-1 through 3.2D-1, 439'-0" Elevation Lower Cable Spreading Room on August 6, 2024
- (4) Fire Zone 5.5-1, 5.5-2, Units 1 & 2 Auxiliary Electrical Room and Fire Zone 5.2-2 Auxiliary Building Division 21 ESF Switchgear Room on August 28, 2024
- (5) Review and assessment of the licensee's failure to meet Plant Barrier Impairment (PBI) requirements, as documented in Issue Report (AR) 4796221 on August 30, 2024
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated internal flooding mitigation protections in Unit 1 Area 5 during an essential service water (SX) pipe replacement on September 30, 2024
===71111.08P - Inservice Inspection Activities (PWR) The inspectors verified that the reactor coolant system boundary, 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 in Unit 1 during refueling outage B1R26 from September 9th, 2024 to September 24th, 2024.
PWR Inservice Inspection Activities Sample - Nondestructive Examination and Welding Activities (IP Section 03.01)===
The inspectors verified that the following nondestructive examination and welding activities were performed appropriately:
- (1) Ultrasonic Examination
- Control Rod Drive Mechanism (CRDM) Housing Welds, 1RC01R H-09 and H-34, Cat. B-O, Item B14.20
- Safety Injection System Pipe Welds, 1SI08FA-3 J29 and J30, Cat. R-A, Item R1.11-5 Surface Examination
- Dye Penetrant (PT) Exam of CRDM Nozzle Overlay on Reactor Pressure Vessel (RPV) Head Penetrations No. 31 and 43, Code Case N-729 Exam, Item B4.20
- PT Exam of CRDM Nozzle Overlay on RPV Head Penetration No. 31, Post-Repair
- Magnetic Particle Exam of RPV Head-to-Flange Weld, 1RC01R RVHC-01, Cat. B-A, Item B1.40 Visual Examination
- RPV Upper Head Visual Exam of Bare Metal Surface and Penetrations, Code Case N-729 Exam, Item B4.10
- RPV Bottom Head Visual Exam of Bottom Mounted Instrument (BMI)
Penetrations and Bare Metal Surface, Code Case N-722 Exam, Item B15.80 Welding Activities
Replacement of U1 SX Piping 1SX27DB-10 from Carbon Steel to Stainless Steel, Work Order (WO) 05029727-01, Weld No. 10 PWR Inservice Inspection Activities Sample - Vessel Upper Head Penetration Inspection
Activities (IP Section 03.02) (1 Sample)
The inspectors verified that the licensee conducted the following vessel upper head penetration inspections and addressed any identified defects appropriately:
- (1) Vessel Upper Head Penetration Examinations and Defect Repair/Removal
- Bare Metal Visual (BMV) Examination of RPV Upper Head Surface Penetrations
- PT Examination of CRDM Nozzle Overlay on RPV Head Penetrations 31 and 43
- PT Examination of CRDM Nozzle Overlay on RPV Head Penetration 31, Post-Repair PWR Inservice Inspection Activities Sample - Boric Acid Corrosion Control Inspection Activities (IP Section 03.03) (1 Sample)
The inspectors verified the licensee is managing the boric acid corrosion control program through a review of the following evaluations:
- (1) Boric Acid Evaluations and Corrective Actions
- Boric Acid Leakage on 1CV02A, ARs 04686053, 04552969, and 04167929
- Boric Acid Leakage on 1CV8119, AR 04563486
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 on-watch licensed operator performance during various activities in the main control room through September 3, 2024.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated the performance of a complex casualty graded scenario by a crew of licensed plant operators in the facility's simulator on July 23, 2024.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (2 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
- (1) Maintenance effectiveness review of the 0A essential service water makeup pump on August 19, 2024
- (2) Maintenance effectiveness review of the Units 1 and 2 diesel generator room ventilation (VC) system following a catastrophic failure of a ventilation fan on August 27, 2024 Quality Control (IP Section 03.02) (1 Partial)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:
(1)
(Partial)
Safety-related diesel engine fuel injectors on September 30, 2024
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) Review and evaluation of the risk associated with a one-time surveillance interval extension for 1B emergency diesel generator monthly testing on July 22, 2024
- (2) Review and evaluation of the risk associated with new fuel receipt and inspection in preparation for Refueling Outage B1R26, as documented in WO 5491204 through August 8, 2024
- (3) Review and evaluation of the risk associated with restoring 125VDC engineered safety feature battery 212 cell above administrative limit after discovery of the cell approaching operability limit on August 21, 2024
- (4) Review and evaluation of the risk management actions associated with a planned Risk Informed Completion Time (RICT) implementation during replacement of Battery 212 on September 6, 2024
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) Evaluation of the operability of several chemical volume control system valves following discovery of the installation of incorrectly rated gaskets, as documented in AR 4783268 on July 5, 2024
- (2) Evaluation of the operability of the 2B component cooling pump following discovery of elevated seal leakage, as documented in AR 4790521 on August 1, 2024
- (3) Evaluation of the operability of the moderator temperature coefficient (MTC) as noted in the core operating limits report (COLR) following incorrect calculation, as documented in AR 4721679 on August 16, 2024
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (2 Samples)
The inspectors evaluated the following temporary or permanent modifications:
- (1) Review of permanent plant modification per engineering change (EC) 634799, CDO - 1SX27DA-10" SX Pipe Replacements with Stainless Steel and Install Line Stop Fitting on 1SX07HB-20".
- (2) Review of temporary plant modification per EC 642106: TCC Temporarily Jumper Out Cell 24 of ESF Battery 212 to Allow 125VDC ESF Batter 212 Operation with 57 Cells
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage Sample (IP Section 03.01) (1 Partial)
(1)
(Partial)
The inspectors evaluated Refuel Outage B1R26 activities from September 8, 2024 to September 30, 2024
71111.24 - Testing and Maintenance of Equipment Important to Risk
The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:
Post-Maintenance Testing (PMT) (IP Section 03.01) (7 Samples)
- (1) Functional and operational testing of power range detector N-42 following troubleshooting and maintenance due to degraded indications, as documented in WO 5555325 on July 12, 2024
- (2) Functional and operational testing of the 0A control room HVAC chiller following unscheduled maintenance, as documented in WO 5426260 on July 30, 2024
- (3) Functional and operational testing of the 2B auxiliary feedwater pump following extent of condition torque checks, as documented in WO 5567419 on August 14, 2024
- (4) Functional and operational testing of the 1B auxiliary feedwater pump following extent of condition torque checks, as documented in WO 5567440 on August 19, 2024
- (5) Functional and operational testing of the 125VDC battery (DC Bus 212) following cell replacement, as documented in WO 5568409 on September 6, 2024
- (6) Functional and operational testing of the 2B emergency diesel generator following maintenance performed during Refueling Outage B1R26, as documented in various WOs on September 30, 2024
- (7) Functional and operational testing of the Unit 1 reactor core through low power physics testing following Refueling Outage B1R26, as documented in WO 5350240 on September 30, 2024
Surveillance Testing (IP Section 03.01) (2 Samples)
(1)2BOSR 8.1.2-1, Unit Two 2A emergency diesel generator operability surveillance on July 12, 2024 (2)2BOSR 5.5.8.SX-4, component cooling heat exchanger essential service water outlet valve stroke surveillance on August 27, 2024
Containment Isolation Valve (CIV) Testing (IP Section 03.01) (1 Sample)
- (1) Local leak rate testing of primary containment isolation valves 1RF026, 1RF027, 1RF055, and 1SI8968, as documented in various WOs on September 26, 2024
71114.06 - Drill Evaluation
Required Emergency Preparedness Drill (1 Sample)
- (1) Observation of the technical support center (TSC) focus area drill that covered the escalation of emergency action levels (EAL) from alert to general emergency due to the loss of fission product barriers on July 10, 2024.
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
- (1) Observation of an emergency preparedness medical drill assessing offsite medical response capabilities on August 8,
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) Workers exiting the primary radiologically controlled area
- (2) Licensee surveys of potentially contaminated material leaving the containment access facility
Radiological Hazards Control and Work Coverage (IP Section 03.04) (3 Samples)
The inspectors evaluated the licensee's control of radiological hazards for the following radiological work:
- (1) Buffing and blending of identified defects on penetration #31 of Unit 1 reactor head
- (2) Local leak rate testing under the transfer canal
- (3) Inspections on the Unit 1 control rod drive mechanisms High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (2 Samples)
The inspectors evaluated licensee controls of the following high radiation areas (HRAs) and very high radiation areas (VHRAs):
- (1) Unit 1 in-core detector thimble tube penetrations
- (2) Unit 1 reactor head stand 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) (1 Sample)
The inspectors evaluated the configuration of the following temporary ventilation systems:
- (1) Portable HEPA Unit #428 in use at Unit 1 Reactor Head
Use of Respiratory Protection Devices (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated the licensees use of respiratory protection devices.
71124.04 - Occupational Dose Assessment
Special Dosimetric Situations (IP Section 03.04) (1 Sample)
The inspectors evaluated the following special dosimetric situations:
- (1) The use of EDEX for Emergent Repairs of Unit 1 Reactor Head
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS08: Heat Removal Systems (IP Section 02.07)===
- (1) Unit 1 (July 1, 2023 through June 30, 2024)
- (2) Unit 2 (July 1, 2023 through June 30, 2024)
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
- (1) Unit 1 (July 1, 2023 through June 30, 2024)
- (2) Unit 2 (July 1, 2023 through June 30, 2024)
MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)
- (1) Unit 1 (July 1, 2023 through June 30, 2024)
- (2) Unit 2 (July 1, 2023 through June 30, 2024)
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 corrective actions associated with AR 4721470, Fuel dilution in 2AF01PB-K diesel engine is in ALERT range.
- (2) The inspectors reviewed the corrective actions associated with AR 4697929, 0FX02PC High Head Flex Pump has Stuck Open or Bad Piston.
71153 - Follow-up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)
The inspectors reviewed, evaluated, and closed the following licensee event reports (LERs):
- (1) Unit 2 LER 05000455/2022-001-01, Volumetric Examinations of Reactor Pressure Vessel Head Core Exit Thermocouple Penetration P-75 Identified an Indication Attributed to Primary Water Stress Corrosion Cracking (ADAMS Accession No.
ML23243A934). The inspectors determined that the cause of the condition described in the LER was not reasonably within the licensees ability to foreseen and corrected and therefore was not reasonably preventable. During the Unit 2 refueling outage in the spring of 2022, volumetric examinations of the reactor vessel head identified a recordable indication in core exit thermocouple penetration number 75 (P-75) that did not meet the applicable acceptance criteria. By letter dated September 29, 2023 (ADAMS Accession No. ML23272A242), Constellation submitted a request for alternative for Post-Peening Reexamination Frequency for Reactor Pressure Vessel Head Penetration Nozzle (RPVHPN) P-75. NRC staff authorized the use of the proposed alternative until the next scheduled inspection in spring 2025. This position was documented under Byron Station, Unit No. 2 - Authorization and Safety Evaluation for Alternative Request No. I4R-24 (ADAMS Accession No.
ML24131A007). No performance deficiency nor violation of NRC requirements was identified. This LER is Closed.
INSPECTION RESULTS
Failure to Satisfy ASME Code Case N-722-1 Examination Requirements for Reactor Coolant System (RCS) Pressure Boundary Welds Cornerstone Significance Cross-Cutting Aspect Report Section Barrier Integrity Green NCV 05000454/2024003-01 Open/Closed
[H.7] -
Documentation 71111.08P The inspectors identified a finding of very low safety significance (Green) and an associated Non-Cited Violation (NCV) of 10 CFR Part 50, Section 50.55a(g)(6)(ii)(E), Augmented ISI requirements: Reactor coolant pressure boundary visual inspections, for the licensees failure to assure the ASME Code Case N-722-1 examination requirements for the Class I RCS instrument connection pressure boundary welds were satisfied. Specifically, during remote visual examination of the Reactor Pressure Vessel (RPV) bottom head, the licensee failed to complete examination of all nozzle-to-thimble guide tube welds as required by N-722-1.
Description:
Byron Unit 1 RPV bottom head has
- (58) Bottom Mounted Instrument (BMI) nozzle penetrations, which require visual examination every other outage. These penetrations are identified as Item Number B15.80 under N-722-1. The penetration nozzles are connected to thimble guide tubes by welds, and these instrument connection welds require visual examination once every interval. These welds are identified as Item Number 15.100 under N-722-1.
On September 9, 2024, during the last outage (B1R26) of the current fourth interval, the licensee performed remote visual examination of the RPV BMI nozzle penetrations, Item Number B15.80, along with the bare metal surface. During the review of the examination records, the inspector selected a few sample areas of the bottom head region for review.
Each of the selected areas represented different geometrical configuration due to the shape of the bottom head. Of particular interest was the instrument connections located near the center of the head. The inspector noted that due to the configuration of the existing lower insulation package below the bottom head, the visibility of the centermost instrument connection welds was either fully or partially obstructed by the existing insulation materials. Consequently, not all welds were within the visual line of sight during the visual examination activity.
Further review of the licensees ISI Program Plan for the current Fourth Ten-Year Inspection Interval, ER-BY-330-1001, Rev. 3, revealed that the instrument connections identified as Item Number 15.100 were listed under Section 2.2.8 of the program plan as not applicable. It was also revealed that these connections had not been listed in the program plan as applicable since the implementation of N-722-1 during the second period of the third interval.
Consequently, the program plan had not required examination of these connection welds.
However, upon detailed review, it was determined these welds should have been identified as applicable under this category.
The licensee was not able to produce evidence that the insulation package under the bottom head was removed to access these welds for the prior N-722-1 related examinations.
Therefore, the licensee concluded that a total of eight centermost instrument connection welds that were visually obstructed by the insulation materials had not been examined since the third interval when the N-722-1 requirements were implemented.
Corrective Actions: The licensee entered the issues into their corrective action program. The licensee verified that the other
- (50) instrument connection welds that were within the visual line of sight had been examined during the N-722-1 activity. The examination verified there were no indications of leakage through these welds. Additionally, the licensee performed evaluation of the
- (8) centermost instrument connection welds that had not been examined.
The evaluation concluded there was reasonable assurance that adequate pressure boundary and structural integrity were maintained. The inspectors reviewed the evaluation. The licensee documented within their corrective action program planned corrective actions to evaluate this issue on Unit 2, the alternate unit, for applicability.
Corrective Action References: AR 04802795
Performance Assessment:
Performance Deficiency: The licensees failure to satisfy the examination requirements of ASME Code Case N-722-1 for the RCS pressure boundary welds was contrary to 10 CFR 50.55a(g)(6)(ii)(E) and was a performance deficiency. Specifically, the licensee did not complete the visual examination of all nozzle-to-thimble guide tube pressure boundary welds during the RPV bottom head visual examination activity.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the RCS Equipment and Barrier Performance attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the licensees failure to complete examination of all Class I nozzle-to-thimble guide tube connection welds to satisfy the requirements of N-722-1 did not provide assurance the RCS pressure boundary was maintained.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors answered No to question, Does the finding involve potential non-compliance with regulatory requirements for protection of the reactor pressure vessel against fracture (e.g., pressure-temperature limits or pressurized thermal shock issues)? under Section B of Exhibit 3 - Barrier Integrity Screening Questions. Therefore, the finding was screened as having very low safety significance (Green).
Cross-Cutting Aspect: H.7 - Documentation: The organization creates and maintains complete, accurate and up-to-date documentation. Through documentation reviews and interviews with licensee staff, the inspectors determined the licensee failed to satisfy the examination requirements of N-722-1 because the examination activities were governed by the licensees ISI program that did not require the examination of the RPV bottom head instrument connection welds.
Enforcement:
Violation: Title 10 of the Code of Federal Regulations, Part 50, Section 50.55a(g)(6)(ii)(E),
Augmented ISI requirements: Reactor coolant pressure boundary visual inspections, stated,
- (1) All licensees of pressurized water reactors must augment their inservice inspection program by implementing ASME Code Case N-722-1, subject to the conditions specified in paragraphs (g)(6)(ii)(E)(2) through
- (4) of this section. The inspection requirements of ASME Code Case N-722-1 do not apply to components with pressure retaining welds fabricated with Alloy 600/82/182 materials that have been mitigated by weld overlay or stress improvement.
The licensees RPV bottom head nozzle-to-thimble guide tube welds were fabricated with Alloy 82 material that have not been mitigated by weld overlay or stress improvement.
ASME Code Case N-722-1 required, in part, that the additional examinations of Table 1 shall be performed for pressurized water reactor plants having partial or full penetration welds in Class 1 components fabricated with Alloy 600/82/182 material.
Table 1 of Code Case N-722-1 required, in part, that the instrument connections identified as Item No. B15.100 be visually examined once per interval.
Contrary to the above, as of September 9, 2024, the licensees inservice inspection program failed to comply with the requirements of ASME Code Case N-722-1. Specifically, the licensee failed to complete visual examination of all Class 1 nozzle-to-thimble guide tube welds to satisfy the requirements of N-722-1. The conditions specified in paragraphs (g)(6)(ii)(E)(2) through
- (4) of Section 50.55a did not apply.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to establish a time-based preventative maintenance schedule for Diesel Generator Ventilation Fans Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000454,05000455/2024003-02 Open/Closed None (NPP)71111.12 A self-revealed finding of very low safety significance (Green) and associated non-cited violation of Technical Specification 5.4.1.a was identified for the licensees failure to establish an appropriate preventative maintenance (PM) schedule for the emergency diesel generator (EDG) ventilation fans. Specifically, time-based inspections including torque checks and other inspections to prevent excess movement of fan assembly components were not conducted on the ventilation fans despite being classified as a component needing this type of PM schedule. The failure to establish an appropriate PM schedule resulted in the loosening of fan blade nuts going unnoticed nor corrected, increased stresses to the fan blades, and ultimately catastrophic failure of the 2A EDG ventilation fan.
Description:
On November 1, 2023, the 2A EDG and associated diesel ventilation fan, 2VD01CA, were started per 2BOSR 8.1.14-1, Unit Two 2A Diesel Generator 24 Hour Endurance Run and Hot Restart Test, for the annual 24-hour endurance run. At approximately 0930 on November 2, 2023, a loud bang was heard in the 2A EDG room and the main control room received the DG ROOM 2A VENT FAN DP - LOW alarm. The 2A EDG was shut down and placed into maintenance outage mode and the vent fan switch placed in the pull-to-lock position. On November 2, 2023, at 0941, the 2A EDG was declared inoperable and unavailable. Repairs to 2VD01CA were completed on November 8, 2023, and at 1615, the 2A EDG was returned to service.
Upon removal, 16 fan blades were broken at or near their bases on the fan hub. Blade fragments were ejected from the fan housing and strewn down the supply ductwork. The hub, with all broken blade roots in place, was transported to the mechanical maintenance shop.
Inspections performed by the licensee determined that three of the 16 blade root connector nuts, which are used to prevent relative motion between the blade root and opening of the fan hub, had excessive looseness. These nuts are intended to be torqued to a minimum of 220 foot-pounds, but the three loose nuts were found to be torqued to less than 50 foot-pounds.
Additional inspection found other signs of improper relative motion between the blade root and hub. This looseness and relative motion during operation resulted in increased bending stresses and premature failure. A corrective action program evaluation (CAPE) determined that the cause of the catastrophic failure of 2VD01CA was high cycle, low stress fatigue of a fan blade, subject to excessive bending induced by a loose fan blade root nut.
A review of operating experience identified catastrophic failures of a fan in the circulating water pump house (CWPH) ventilation caused by high cycle, low stress fatigue from Byron (2013) and Braidwood (2014). Additionally, in 2019, while the auxiliary building ventilation system was in operation, two exhaust fan blades fractured due to high cycle, low stress fatigue. As a result of the failures of the CWPH fans, a time-based PM task was created and implemented to address the cause of the failure, which was not implemented for similar fans, including 2VD01CA.
Per ER-AA-200-1001, Equipment Classification, the fan was classified as a Non-Critical, Mild Environment, Low Cycle component and should have had time-based inspections. The CAPE determined the lack of regular inspection and torque verification was a casual factor of the failure. Inadequate preventative maintenance led to a loose blade going unnoticed or corrected that ultimately failed due to increased bending stress and high cyclic fatigue.
Corrective Actions: In response to the failure, the licensee performed extent of condition inspections on the three remaining EDGs prior to each of their next scheduled run and didn't not find additional loose bolts. Additionally, a CAPE was performed to review and document the failure mechanism of the fan and provide a more in depth understanding of the issue and necessary corrective actions to mitigate and/or eliminate reoccurrence. The licensee has reclassified the diesel ventilation fans as critical components and are creating and implementing new PMs to perform additional inspections, including torque checks.
Corrective Action References: 4714774; Low dP Alarm on 2A DG Vent Fan; 11/02/2023 4716165; 1A EDG EOC work required for DG Vent Fan Failure; 11/08/2023 4716167; 1B EDG EOC work required for DG Vent Fan Failure; 11/08/2023 4716168; 2B EDG EOC work required for DG Vent Fan Failure; 11/08/2023
Performance Assessment:
Performance Deficiency: The inspectors determined that the failure to create and implement a preventative maintenance schedule for the EDG ventilation fans was contrary to Technical Specification 5.4.1.a and was a performance deficiency. Specifically, the failure to perform torque checks and other inspections to prevent excess movement of fan assembly components led to allowing a loose blade to go unnoticed nor corrected, that ultimately failed due to increased bending stress and high cyclic fatigue.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the licensees preventative maintenance and testing program did not identify required tests and inspections and was not implemented in such a manner to prevent failure. The inadequate PM frequency and scope for the EDG ventilation fans resulted in catastrophic failure of 2VD01CA which rendered the 2A EDG inoperable and unavailable.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors compared the finding with the examples listed in Inspection Manual Chapter (IMC)0612, Power Reactor Inspection Reports, Appendix E, Example of Minor Issues and found example 4.l to be similar. Specifically, time-based preventative maintenance was not conducted on the EDG ventilation fans despite being classified as a component needing this type of PM schedule. The failure to establish an appropriate PM schedule resulted in the loosening of fan blade nuts going uncorrected which increased stresses to the fan blades, and ultimately catastrophic failure of the 2A EDG ventilation fan. This resulted in the inoperability and unavailability of the 2A EDG.
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: Byron Unit 2 Technical Specifications 5.4.1.a, requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978.
NRC Regulatory Guide 1.33, Revision 2, Appendix A, Section 9 addresses Procedures for Performing Maintenance and Section 9.b states, in part, that preventative maintenance schedules should be developed for inspections of equipment.
Contrary to the above, prior to the catastrophic failure of the diesel ventilation fan on November 2, 2023, the licensee failed to develop a preventative maintenance schedule for inspections of susceptible portions of the EDG ventilation fans. Specifically, the licensee failed to establish or implement a time-based PM schedule as necessitated by their classification as non-critical, mild environment, low cycle components.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Observation: Diesel driven auxiliary feedwater pump fuel oil dilution 71152A The inspectors performed a detailed review of AR 4721470, Fuel dilution in 2AF01PB-K diesel engine is in ALERT range. On December 4, 2023, Byron received sample results back from the 2B diesel driven auxiliary feedwater pump (AFP) that showed crank case fuel dilution levels high out of range per MA-AA-716-230-1001, Oil Interpretation Guidelines.
Confirmatory sample results received on December 7, 2023, confirmed an unfavorable trend in fuel dilution and viscosity.
Braidwood had experienced similar fuel dilution issues in the months preceding the issues at Byron. Byron took proactive measures during an ongoing AFP work window in October 2023 that coincided with the discovery of the issues at Braidwood. Following the issues in December, Byron entered an emergent work window to replace the crank case oil and perform additional inspections and maintenance. Following completion of the emergent work, the AFP passed all post maintenance testing and was returned to service.
Both stations identified areas for improvements in their maintenance strategy during their investigations. These included enhancing pressure testing practices, incorporating vendor recommended torque values for fuel injector bolts, and not reusing end fittings for the fuel pipes.
The inspectors concluded that the licensees actions were in accordance with their corrective action program and reasonable given the overall safety significance of the issue. Byron incorporated lessons learned in real-time based on the discovery at Braidwood, such as bearing inspections that were missed by Braidwood and improvements in maintenance practices for the abovementioned gaps. Additionally, tests performed by the licensee demonstrated that, even with increased fuel dilution, the AFP would be capable of performing its safety-related function for the required mission time.
No findings or violations of NRC requirements of more than minor safety significance were identified by the inspectors in the course of this review.
Observation: 0C high head FLEX pump unavailable greater than 90 days 71152A The inspectors performed a detailed review of several issue reports (ARs) related to the 0C high head FLEX pump (0FX02PC). These included, but were not limited to:
- AR 4697929, 0FX02PC High Head Flex Pump has Stuck Open or Bad Piston
- AR 4717747, 0BOL FX1 Comp Actions
- AR 4722187, Long Term FLEX Pump Storage Strategy
- AR 4753970, C High Head FLEX Pump Needs further repair
- AR 4759115, Create WR for installation of FLEX pump cooler
- AR 4765443, 0FX02PC-0C high head FLEX needs additional work
- AR 4775101, Delays in 0C Flex Pump from Vendor
- AR 4781773, Vendor Did Not Fully Implement Supplemental Oil Cooler MOD
- AR 4782124, Delays in restoration of the 0C High Head Flex pump
- AR 4780856, 0FX01PC and 0FX02PC Original Supply Receipt Inspection On March 12, 2012, the NRC directed licensees to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities in response to a beyond-design-basis external event. This was later codified under 10 CFR 50.155. On December 7, 2016, the licensee confirmed development and implementation of these strategies using low, medium, and high head pumps, referred to as the FLEX pumps. The licensee used the guidance in NEI 12-06 and obtained three of each type of pump (based on "N+1" philosophy). NEI 12-06 guidance was also used when formulating the licensee's mitigation plan which allowed for one of these pumps to be out of service for up to 90 days.
On August 22, 2023, the licensee with vendor support conducted full flow testing on 0FX02PC where it did not meet the acceptance criteria as stated in the test procedure when it failed to develop proper discharge pressure. 0FX02PC was secured per vendor instruction and declared not functional.
On February 28, 2024, the licensee attempted a flow test following vendor repairs on 0FX02PC and was unsuccessful. When the hose was disconnected, ice was identified being pumped out. The vendor recommended removing the pump from the site to perform further investigation and repair.
On June 19, 2024, during return receipt inspection of 0FX02PC from the vendor, the licensee identified that the planned modification to support an additional oil cooler was not complete.
The modification was missing a new relief valve and manifold that would allow maximum output of the auxiliary charge pump and allow adequate backpressure on the auxiliary oil pump.
As of September 30, 2024, 0FX02PC has been out of service for a total of 405 days, or 315 days beyond the 90 days permitted by the licensees mitigation plan.
The inspectors examined the licensees recent corrective action to determine whether other outstanding issues and questions had been addressed, but the inspectors acknowledge that not all investigative and maintenance activities have been completed. Several observations by the inspectors include, but were not limited to:
- Due to the inability to meet acceptance criteria, the vendor recommended the installation of a second hydraulic oil cooler on all three high head flex pumps, including 0FX02PC. The need to equip a second hydraulic oil cooler to meet acceptance criteria is indicative of potential shortcomings in the original design of the pumps as purchased.
- AR 4780856 identified medium head flex pump 0FX01PC and 0FX02PC did not have a supply receipt inspection conducted as required, and therefore, there is no documentation that a quality control inspection was performed.
- The inability to return 0FX02PC to service within the 90 days allowed by their mitigation plan/strategy constituted a performance deficiency that was within their ability to foresee, and which should have been prevented. However, since the licensee maintained the ability to implement their mitigation strategy even with 0FX02PC out of service for the extended period, the issue was minor.
No findings or violations of NRC requirements of more than minor safety significance were identified by the inspectors in the course of this review.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On October 10, 2024, the inspectors presented the integrated inspection results to H. Welt, Site Vice President, and other members of the licensee staff.
- On September 20, 2024, the inspectors presented the radiation protection inspection results to S. Harvey, Plant Manager, and other members of the licensee staff.
- On September 24, 2024, the inspectors presented the inservice inspection results to H. Welt, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
BOP AF-E2
Unit 2 Auxiliary Feedwater Electrical Lineup
BOP AF-M2
Auxiliary Feedwater System Valve Lineup
BOP CD-M2
Condensate System Lineup
BOP DO-M2
Diesel Fuel Oil System Valve Lineup
Unit 0 Fuel Pool Cooling System Electrical Lineup
Fuel Pool Cooling and Cleanup System Valve Lineup
BOP RH-E1
Unit 1 Residual Heat Removal System Valve Lineup
BOP RH-M1
Unit 1 Residual Heat Removal System Electrical Lineup
BOP SI-E1
Unit 1 Safety Injection System Electrical Lineup
BOP SI-M1
Unit 1 Safety Injection System Valve Lineup
BOP SX-M2A
Unit 2 Train A Essential Service Water System Valve Lineup
Procedures
BOP SX-M2B
Unit 2 Train B Essential Service Water System Valve Lineup
Corrective Action
Documents
04796221
APS: PBI Requirements not met
08/22/2024
Pre-Fire Plan
- 132
Fire Zone 11.4-0 North Auxiliary Building 383-0 Elevation
General Area - North
Pre-Fire Plan
- 135
Fire Zone 11.4A-0 Auxiliary Building 383-0 Elevation Control
Room Refrigeration Equipment Room
Pre-Fire Plan #19
Fire Zone 3.2A-1 Auxiliary Building 439-0 Elevation Lower
Cable Spreading Room
Pre-Fire Plan #21
Fire Zone 3.2B-1 Auxiliary Building 439-0 Elevation Lower
Cable Spreading Room
Pre-Fire Plan #23
Fire Zone 3.2C-1 Auxiliary Building 439-0 Elevation Lower
Cable Spreading Room
Pre-Fire Plan #25
Fire Zone 3.2D-1 Auxiliary Building 439-0 Elevation Lower
Cable Spreading Room
Pre-Fire Plan #44
Fire Zone 5.2-2 Auxiliary Building 426-0 Elevation Division 21
ESF Switchgear Room
Pre-Fire Plan #49
Fire Zone 5.5-1 Auxiliary Building 451-0 Elevation Unit 1
Auxiliary Electrical Room
Fire Plans
Pre-Fire Plan #50
Fire Zone 5.5-2 Auxiliary Building 451-0 Elevation Unit 2
Auxiliary Electrical Room
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Pre-Fire
Plan #133
Fire Zone 11.4-0 South Auxiliary Building 383-0 Elevation
General Area - South
Pre-Fire
Plan #134
Fire Zone 11.4-0 West Auxiliary Building 383-0 Elevation
General Area - West
Calculations
Auxiliary Building Flooding Calculations
Corrective Action
Documents
4802550
B1R26-1B SX Line Repl-Grout Set Needed for Pipe Support
09/17/2024
BAP 1100-3A3
Pre-Evaluated Plant Barrier Matrix
Procedures
Plant Barrier Control Program
04167929
Inactive Bolted Connection Leak on 1CV02A
08/28/2018
04552969
1CV02A - Expired BACC Evaluation
2/06/2023
04561059
Recordable Indications - B1R25 ASME Sec. XI, IWE Exam
03/10/2023
04561270
Recordable Indications on 1RC01PD RCP Seal Housing Bolts
03/11/2023
04561294
B1R26 ISI - Relevant Condition on 1SX01PA Support
03/11/2023
04563486
1CV8119 Appears to be Leaking
03/20/2023
04686053
INPO: Incorrect Corrosion Calculation Used in BACC Evals
06/21/2023
04774048
Trend - Missing Documentation from ASME R/R Work
Packages
05/14/2024
04774906
Missing Welding Docs, WO:01431732-01
05/17/2024
04782912
ASME Replacement WO#05322470 Documentation
Incomplete
06/25/2024
04803434
WO 05347432-01 ASME R/R Closeout Review
09/20/2024
Corrective Action
Documents
04803746
B1R26LL: NOS QV ID Weld Rod Ticket Issue
09/23/2024
Corrective Action
Documents
Resulting from
Inspection
04802795
NRC ID: N-722-1 Augmented ISI Program Implementation
Issues
09/18/2024
Drawings
1193E54 Sheets
and 2
Byron/Braidwood/Marble Hill Unit 1 Bottom Mounted
Instrumentation Field Assembly
1CV02A
Evaluation of Leakage from Bolted Connection from 1CV02A
06/22/2023
Engineering
Evaluations
1CV8119
Evaluation of Leakage from Bolted Connection from 1CV8119
08/29/2023
Miscellaneous
Process
Specification
2127JS
Welding Reactor Vessel Bottom Mounted Instrumentation
Connections
03/07/1983
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Magnetic Particle Examination Report for RPV Head-to-Flange
09/20/2024
Magnetic Particle Examination Report for RPV Head-to-Flange
09/20/2024
Liquid Penetrant Examination for RPV Head Penetration No.
09/13/2024
Liquid Penetrant Examination for RPV Head Penetration No.
09/14/2024
Liquid Penetrant Examination for RPV Head Penetration No.
31, Post-Repair
09/19/2024
UT Calibration/Examination Report for Weld 1RC-01-R/H-34
09/20/2024
UT Calibration/Examination Report for Weld 1SI08FA-3/J29
09/20/2024
UT Calibration/Examination Report for Weld 1SI08FA-3/J30
09/20/2024
UT Calibration/Examination Report for Weld 1RC-01-R/H-09
09/20/2024
Visual Examination NDE Report for RPV Upper Head
Penetration Surface
09/22/2024
NDE Reports
BAR26-VEN-001
Visual Examination NDE Report for RPV BMI
09/14/2024
Liquid Penetrant (PT) Examination
Magnetic Particle (MT) Examination
Ultrasonic Examination in Accordance with ASME Section XI,
Appendix III
Boric Acid Corrosion Control (BACC) Program
Boric Acid Corrosion Control (BACC) Program Identification,
Screening, and Evaluation
Bare Metal Visual Examination for Nickel Alloy Materials
ER-BY-330-1001
Byron Generating Station Units 1 & 2, Inservice Inspection
(ISI) Program Plan, Fourth Ten-Year Inspection Interval
ER-BY-330-1002
Byron Generating Station Units 1 & 2, Inservice Inspection
(ISI) Classification Basis Document, Fourth Ten-Year
Inspection Interval
PDI-UT-2
Generic Procedure for the Ultrasonic Examination of Austenitic
Pipe Welds
J
Procedures
WPS 8-8-GTSM
ASME Welding Procedure Specification Record
04836037-03
NDE Visual Exam of RX Head CRDM Seismic Support Tie
Rods
03/22/2020
Work Orders
05029727-01
Replace 1SX27DB-10 with Stainless Steel
4701020
0A SX Makeup Pump Trip
09/07/2023
4701152
Potential Trend in 0A SX M/U Pump Trips
09/08/2023
4104858
0B SX Makeup Pump Tripped During Monthly Surveillance Ru
2/16/2018
4709470
1B AF Pump EOC Fuel Dilution Review Results
10/13/2023
4710871
2B AF Diesel Rebuilt Injectors Did Not Pass Inspection
10/19/2023
4714774
Low dP Alarm on 2A DG Vent Fan
11/02/2023
4716165
EOC Work Required for DG Vent Fan Failure
11/08/2023
4716167
EOC Work Required For DG Vent Fan Failure
11/08/2023
4716168
EOC Work Required for DG Vent Fan Failure
11/08/2023
4719499
1VD02CC Tripping on High DP
11/24/2023
4739352
01/30/2024
4748804
Potential Trend for Ventilation Equipment
2/08/2024
4755659
Revise BOP DG-11T2 to Include VD Components
03/05/2024
4761713
0A SX M/U Pump Trip
03/28/2024
4763519
Refurbished Injector for 16V149 Aux Feed Diesel
04/04/2024
4765868
Results for 2B EDG Fuel Injector Testing
04/09/2024
4766509
04/15/2024
Corrective Action
Documents
4796271
NOS ID: CA Closed without Actions Being Implemented
08/22/2024
Maintenance Rule (a)(1) Determination for 0A SX Makeup
Pump Trip 04701020
01/31/2024
Miscellaneous
BYR-33907
Power Labs Failure Analysis of Relay and Relay Bases for the
0A Essential Service Water Makeup Pump
05/21/2024
Maintenance Rule Implementation per NEI 1810
Procedures
Maintenance Rule - (a)(1) And (a)(2) Requirements
4787078
One-Time Extension of 1B EDG Monthly Surveillance
07/15/2024
Corrective Action
Documents
4793742
2 Battery Below Admin Level
08/14/2024
Engineering
Changes
2106
TCC Temporarily Jumper Out Cell 21 of ESF Battery 212 to
Allow 125 VDC ESF Batter 212 Operation with 57 Cells
000
RICT Package for Planned DC Bus 212 Cell Replacement
09/05/2024
BY-24-001
Surveillance Test Interval Evaluation Form for One-Time
Revision to 1B DG Monthly Surveillances to 62 Days
000
Miscellaneous
PORC Meeting
Plant Operations Review Committee for Surveillance
07/18/2024
- 24-015
Frequency Control Program Change for a One-Time Revision
to 1B DG Monthly Surveillances to 62 Days
PRA Analysis BY-
STI-061
Risk Evaluation of One-Time Surveillance Interval Extension
for 1B EDG Monthly Test (SRs 3.8.1.2, 3.8.1.3, 3.8.1.4,
3.8.1.5, 3.8.1.6, 3.8.3.1, 3.8.3.3)
Implementation of the Technical Specification Surveillance
Frequency Control Program
Risk Management Documentation
Procedures
Risk Assessment of Surveillance Test Frequency Changes
Work Orders
5491204
U-1 Receive & Inspect New Fuel
08/09/2024
4451252
2A CC Pump Inboard Seal Leak
10/06/2021
4476583
2A CC Pump Inboard Seal Leak Got Worse
2/07/2022
4694519
CID 482906 Description and Part Numbers Dont Align
08/03/2023
21679
COLR MTC (Section 2.3.1) Incorrectly Calculated - BYR/BRW
2/05/2023
22310
Incorrect MTC Elimination checks for Byron and Braidwood
2/08/2023
4783268
CID 482906 Byron Installation History
06/26/2024
Corrective Action
Documents
4790521
2B CC Pp Inboard Seal Leaking
07/30/2024
Procedures
MA-AA-716-010-
1104
Mechanical Seal Leakage Evaluation and Reporting
Calculations
1346-0076-RPT-
001
Design Report for Byron SX Modified Piping Subassembly for
27883
2SX27DB-10" SX Pipe Replacements with Stainless Steel
000
631320
CDO - 1SX27DB-10" SX Pipe Replacements with Stainless
Steel and Install Line Stop Fitting on 1SX07HB-20"
000
634799
CDO - 1SX27DA-10" SX Pipe Replacements with Stainless
Steel and Install Line Stop Fitting on 1SX07HA-20"
000
Engineering
Changes
639768
MR90 Evaluation for Use of Line Stop on 1SX07HB-20" and
Pipe Disconnection on Line 1SX27DB-10" with Valve
1SX057B Removed
000
Engineering
Evaluations
BYR99-122
Review of Design Report for ITT 2.0 Inch Class 150 lb. Ball
Valve (ITT Corporation Industrial Process, Design Report
W-521, Revision 13) for EC 634799
4785438
N-42 Lower Detector Delta I Indications/Alarms Failing
07/07/2024
4786475
0A VC Chiller Secured due to Lowering Oil Level
07/11/2024
Corrective Action
Documents
4789581
MA-AA-716-006 Improvements Needed Based On 0A VC
Chiller Oil
07/24/2024
4793457
2B AF Pump Turbo Exhaust Disconnected
08/12/2024
4793475
Work Request Needed for 1B Aux Feed Pump
08/12/2024
4793476
Work Request Needed for 2B Aux Feed Pump
08/12/2024
4793637
2B AF Pump Extent of Condition
08/13/2024
4793642
1B AF Pump Extent of Condition
08/13/2024
4793644
AF Pump Clamp Torquing Discrepancy during EOC
08/13/2024
4801862
As Found LLRT on P-55 UNSAT
09/14/2024
1BOSR 0.5-
2.AF.3-1
Unit One Auxiliary Feedwater Valves Train A Indication Test
1BOSR 6.1.1-18
Unit One Primary Containment Type C Local Leakage Rate
Tests and IST Tests of Containment Floor Drains System
1BOSR 6.1.1-22
Unit One Primary Containment Type C Local Leakage Rate
Test and IST Tests of Safety Injection System
1BOSR 7.5.4-2
Unit 1 Diesel Driven Auxiliary Feedwater Pump Monthly
Surveillance
1BOSR 8.1.11-2
Unit One 1B Diesel Generator Sequencer Test
1BOSR 8.1.17-2
Unit One 1B Diesel Generator SI Signal Override Test
1BOSR 8.1.9-2
Unit One 1B Diesel Generator Safe Shutdown Sequencer and
Single Load Rejection Test
2BOSR 5.5.8.SX-
Component Cooling Heat Exchanger Essential Service Water
Outlet Valve Stroke Surveillance
2BOSR 7.5.4-2
Unit Two Diesel Driven Auxiliary Feedwater Pump Monthly
Surveillance
2BOSR 8.1.2-1
Unit Two 2A Diesel Generator Operability Surveillance
BOP AF-5
Motor Driven Auxiliary Feedwater Pump 1A Startup on Recirc
BOP DG-11T2
Diesel Generator Operating Log
Procedures
NF-BY-510
Low Power Physics Test Program
5301687
LR-U1 Motor Driven AF Pump - Clean and Inspector Lube Oil
Cooler
09/26/2024
5330914
(Sample/Change) Motor Driven Aux Feedwater Pump 1A
09/26/2024
5347121
Rebuild Actuator, Regulators/Replace Elastomers
09/23/2024
5347127
1RF055 IST Relief Valve Test (Pre/Post LLRT Req)
09/20/2024
5347369
1B Diesel Generator SI Signal Override Test
09/23/2024
Work Orders
5347370
1B Diesel Generator Safe S/D Sequencer and Single Load
Reject
09/26/2024
5347371
1B Diesel Generator Sequencer Test
09/26/2024
5347513
LLRT for P-55 - 1SI8880 and 1SI8968
09/23/2024
5347517
LLRT for P-47 - 1RF026, 1RF027 and 1RF055
09/20/2024
5350240
Low Power Physics Testing Program Using the ADRC
09/30/2024
26260
0A VC Chiller Adjust Oil Level as Required for - 2024
07/30/2024
5551220
(NEIL)-LR-2A Diesel Generator Operability Surveillance
07/05/2024
5555325
Perform N-42 Troubleshooting
07/12/2024
5567419
Work Request Needed for 2B Aux Feed Pump
08/14/2024
5567440
Work Request Needed for 1B Aux Feed Pump
08/14/2024
5568009
2 Battery Below Admin Limit
09/06/2024
5568409
NERC-Quarterly 125VDC Battery Surveillance - 2DC02E
09/06/2024
Addendum 3
Constellation Emergency Action Levels for Byron Station
ERO Fundamentals
Procedures
Drills and Exercise Program
BY-1-24-00647
Penetration - Prep & PT (P-31/43)
BY-1-24-00647
CRDM Inspection & Associated Activities - No Under Head
Work
BY-1-24-00649
Emergent Rx Head Repair
ALARA Plans
BY-1-24-00649
Emergent Rx Head Repair
04679377
Unanticipated Dose Rate Alarm
05/19/2023
04681694
05/31/2023
04692990
New Serv. Bldg. High Temp Impacting Required RP WBC
Units
07/27/2023
04707535
Self-Assessment Discrepancies Identified
10/06/2023
04711416
Level 2 PCE
10/21/2023
04799820
PEI doc. Not Completed / Turned Into Records Timely
09/06/2024
Corrective Action
Documents
04801438
Poor Rad Worker Behaviors While Working Around Posted
09/13/2024
Corrective Action
Documents
Resulting from
Inspection
04803132
NRC Observations on Under Head Work
09/19/2024
NISP-RP-003
Radiological Air Sampling
Procedures
NISP-RP-010
Radiological Job Coverage
Determination of Alpha Levels and Monitoring
Determination of Alpha Levels and Monitoring
Controls for High and Locked High Radiation Areas
Controls for Very High Radiation Areas
Additional High Radiation Exposure Control
RP-AA-503-F-01
Unconditional Release Instructions Using the Tool and
Equipment Monitor (TEM) for Personal Items Used in the
Radiologically Controlled Area (RCA) and in a Contaminated
Area
24-224617
Head Stand Scaffold B-6039 and B-0640
09/13/2024
24-224691
Under Head Survey For Pen34 Inspection
09/15/2024
Radiation Surveys
24-224988
Head Stand Scaffold B-6035
09/18/2024
BY-1-24-00649
Emergent Rx Head Repair
Radiation Work
Permits (RWPs)
BY-1-24-00649
Emergent Rx Head Repair
Contamination Control Self-Assessment
10/30/2023
Self-Assessments
AR 04540871-02
Control of Radioactive Material
10/30/2023
Operation and Inspection of the 3M Versaflo TR-300,
TR-300+ PAPR System
Procedures
Use of Air Movers/Portable Fans in Radiologically Controlled
Areas
Miscellaneous
Emergent RX Head Repair Multiple Dosimetry EDEX
Evaluation Sheet
09/13/2024
Procedures
Dosimetry Issue, Usage, and Control
NRC Performance Indicator Data; Mitigating
Systems - Mitigating System Performance Index for Residual
Heat Removal Systems
07/01/2023-
06/30/2024
NRC Performance Indicator Data; Mitigating
Systems - Mitigating System Performance Index for Cooling
Water Systems
07/01/2023-
06/30/2024
71151
Miscellaneous
NRC Performance Indicator Data; Mitigating
Systems - Mitigating System Performance Index for Heat
Removal Systems
07/01/2023-
06/30/2024
4697929
0FX02PC High Head Flex Pump has Stuck Open or Bad
Piston
08/22/2023
4717747
0BOL FX1 Comp Actions
11/15/2023
Corrective Action
Documents
21470
Fuel dilution in 2AF01PB-K diesel engine is in ALERT range
2/04/2024
22187
Long Term FLEX Pump Storage Strategy
2/07/2023
22225
2B AF Diesel Crankcase Confirmatory Oil Sample Results
2/07/2024
4753970
C High Head FLEX Pump Needs Further Repair
2/28/2024
4759115
Create WR for Installation of FLEX Pump Cooler
03/19/2024
4765443
0FX02PC-0C High Head FLEX Needs Additional Work
04/11/2024
4775101
Delays in 0C Flex Pump from Vendor
05/19/2024
4780856
0FX01PC and 0FX02PC Original Supply Receipt Inspection
06/14/2024
4781773
Vendor Did Not Fully Implement Supplemental Oil Cooler
06/19/2024
4782124
Delays in restoration of the0C High Head Flex pump
06/21/2024
P21-12182023-
FN
10CFR Part 21 Final Notification of Defect with Detroit
Diesel/MTU Fuel Injectors PN R5229660 Cat ID#0001390618
Miscellaneous
P21-12182023-IN
10CFR Part 21 Initial Notification of Defect with Detroit
Diesel/MTU Fuel Injectors PN R5229660 Cat ID#0001390618
0BOSR FX-A1
Flex Pump Annual Flow Surveillance
Diverse and Flexible Coping Strategies (FLEX), Spent Fuel
Pool Instrumentation (SFPI), and Hardened Containment Vent
System (HCVS) Program Document
Procedures
MA-AA-716-230-
1001
Oil Analysis Interpretation Guidelines
Corrective Action
Documents
4786272
U2 RPVH Pen-75 Flaw Repair WO and Comp. Action Not
Needed
07/11/2024
LER 2022-001-01
Byron Station Unit 2 Volumetric Examinations of Reactor
Pressure Vessel Head Core Exit Thermocouple Penetration
P-75 Identified an Indication Attributed to Primary Water Stress
Corrosion Cracking
04/23/2024
Letter BYRON
23-0042
Licensee Event Report (LER) Supplement
No. 455-2022-001-01 Byron Station Unit 2 Volumetric
Examinations of Reactor Pressure Vessel Head Core Exit
Thermocouple Penetration P-75 Identified an Indication
Attributed to Primary Water Stress Corrosion Cracking
08/31/2023
Miscellaneous
Relief Request
Alternative for Post-Peening Reexamination Frequency for
Reactor Pressure Vessel Head Penetration Nozzle Number 75
09/29/2023