Text

Integrated Inspection Report 05000454/2023004 and 05000455/2023004
	ML24032A271
Person / Time
Site:	Byron
Issue date:	02/02/2024
From:	Hironori Peterson; NRC/RGN-III/DORS/RPB3
To:	Rhoades D; Constellation Energy Generation, Constellation Nuclear
References
	IR 2023004
	Download: ML24032A271 (1)
	v • d • e

SUBJECT:

BYRON STATION - INTEGRATED INSPECTION REPORT 05000454/2023004 AND 05000455/2023004

Dear David Rhoades:

On December 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Byron Station. On January 18, 2024, the NRC inspectors discussed the results of this inspection with A. Schuerman, Plant Manager, and other members of your staff. The results of this inspection are documented in the enclosed report.

No findings or violations of more than minor significance were identified during this inspection.

This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Hironori Peterson, 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:

NPF-37 and NPF-66

Report Numbers:

05000454/2023004 and 05000455/2023004

Enterprise Identifier:

I-2023-004-0046

Licensee:

Constellation Energy Generation, LLC

Facility:

Byron Station

Location:

Byron, IL

Inspection Dates:

October 01, 2023 to December 31, 2023

Inspectors:

B. Bergeon, Senior Operations Engineer

N. Bolling, Project Engineer

J. Cassidy, Senior Health Physicist

A. Demeter, Resident Inspector

G. Hansen, Sr. Emergency Preparedness Inspector

R. Knutson, Illinois Emergency Management Agency

G. Roach, Senior Operations Engineer

J. Robbins, Senior Resident Inspector

A. Shaikh, Senior Reactor Inspector

Approved By:

Hironori Peterson, 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

No findings or violations of more than minor significance were identified.

Additional Tracking Items

None.

PLANT STATUS

Unit 1 began the inspection period operating at full power. On September 16,2023, power was reduced to support replacement of a 1A reactor coolant loop flow instrument. Subsequently, the unit returned to full power. With the exception of minor reductions in power to support scheduled testing activities and load changes requested by the transmission system dispatcher, the unit remained operating at or near full power for the remainder of the inspection period.

Unit 2 began the inspection period operating at full power. With the exception of minor reductions in power to support scheduled testing activities and load changes requested by the transmission system dispatcher, the unit remained operating at or near full power until September 20, 2023. On October 9,2023, the unit was shut down. Following completion of refueling and other maintenance activities, the reactor was restarted and taken critical on October 26, 2023. The unit reached full power operation on October 29, 2023, and continued operating at or near full power for the remainder of the inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

REACTOR SAFETY

71111.01 - Adverse Weather Protection

Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures on November 21, 2023.

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 2 A Train of the Residual Heat Removal (RH) System during Refuel Outage B2R24 on October 11, 2023

(2) Unit 2 B Train of RH System during Refuel Outage B2R24 on October 19, 2023

(3) Unit 1 Spent Fuel Pool Train during Refuel Outage B2R24 on October 24, 2023

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (3 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Storage Tank Rooms following discovery of a leaking sprinkler in the 2B Diesel Oil Storage Tank (DOST) Room, as documented in Issue Report (IR) 4706956 on October 10, 2023

(2) Units 1 and 2 Auxiliary Feedwater (AF) Pump and Day Tank Rooms following discovery of several leaking CO2 valves, as documented in various IRs on October 11, 2023

(3) Review of disposition and acceptability of ultrasonic testing measurements of fire protection piping, as documented in various IRs on October 11, 2023

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated flooding mitigation protections in the Unit 2 Tendon Tunnel following the discovery of standing water in the tunnel, as documented in IR 4706273 on October 19, 2023.

===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 from October 10 to 17, 2023.

PWR Inservice Inspection Activities Sample - Nondestructive Examination and Welding Activities (IP Section 03.01)===

Main article: IP 71111.08

The inspectors verified that the following nondestructive examination and welding activities were performed appropriately:

(1)

Ultrasonic Examination on 2RC14AD-2 (Augmented MRP-146 exams) 2" Branched Connection off Reactor Coolant System (RCS) Leg

Magnetic Particle Examination of 2SX06BB Closure Plate

Liquid Penetrant Examination of Reactor Pressure Vessel (RPV) Upper Head Penetrations 6 and 68

2AF00A IST Disassembly and Inspection Welding 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)

RPV Upper Head Penetrations Bare Metal Visual (BMV) Examination 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)

IR 04678585 - Inactive Boric Acid Leak on 2CS01AA-16" Bolted Flange

IR 04666344 - 2CV8516 Cation Inlet Isolation Leak

IR 04501664 - Active Boric Acid Leak on 2FI-0631 Threaded Fittings

IR 04506666 - Active Boric Acid Leak from Flange Upstream of 2SI077

71111.11 A - Licensed Operator Requalification Program and Licensed Operator Performance Requalification Examination Results (IP Section 03.03)

Main article: IP 71111.11

(1) The inspectors reviewed and evaluated the licensed operator examination failure rates for the requalification annual operating exam administered between August 15 and September 25, 2023.

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 various on-watch shift crew observations including shutdown, cooldown, and Reactor Coolant System (RCS) drain down to reduced inventory for Unit 2 Refuel Outage B2R24 on October 26, 2023.

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) Maintenance effectiveness review associated with the 2 A Emergency Diesel Generator Ventilation System following the failure of a ventilation fan, as documented in IR 4714774 on November 15, 2023.

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (1 Sample)

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) Evaluation of the B2R24 Shutdown Safety Plan, as documented on September 21, 2023, on October 2, 2023.

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:

(1) Evaluation of the operability of 2RH8716B following changes in conservative uncertainties, as documented in IR 4701984 on November 14, 2023

(2) Evaluation of the operability of valve 2AF013A following issues stroking, as documented in IR 4707513 on October 6, 2023

(3) Evaluation of the operability of 2 A Diesel Generator following the failure of the vent fan, as documented in IR 4714774 on November 2, 2023

(4) Evaluation of the operability of valve 2AF005G following issues stroking, as documented in IR 477822 on October 7, 2023

(5) Evaluation of the operability of the 2B Reactor Coolant Pump following identification of noises during startup and shutdown, as documented in IR 4708074 on October 9, 2023

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated refueling outage B2R24 activities from October 9 through October 26, 2023.

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) (5 Samples)

(1) Functional and operational testing of the 2B AF Pump testing following maintenance, as documented in multiple work orders (WOs) on October 26, 2023

(2) Moveable Incore Detectors and Power Distribution Monitoring System testing following maintenance, as documented in multiple WOs on October 30, 2023

(3) Functional and operational testing of the Fuel Transfer System following load cell following maintenance, as documented in WO 5309497 on October 11, 2023

(4) Functional and operational testing of Unit 2 Containment Recirculation Sump Outlet Isolation Valve, 2SI8811B, following maintenance, as documented in WO 5126812 on October 3, 2023

(5) Functional and operational testing of the 2 A Diesel Generator Ventilation System following failure of fan 2VD01CA, as documented in WO 5414289 on November 08, 2023

Surveillance Testing (IP Section 03.01) (3 Samples)

(1) Unit 2 2B Diesel Generator (DG) Surveillance testing, as documented in multiple WOs on October 19, 2023

(2) Multiple surveillances to restore operability to the 2B AF pump, as documented in various WOs on October 26, 2023

(3) Unit Common 0 A Essential Service Water Makeup Pump Surveillance testing, as documented in WO 5415304 on November 29, 2023

Inservice Testing (IST) (IP Section 03.01) (1 Sample)

(1) Unit 2 Comprehensive Inservice Testing (IST) Requirements for Safety Injection (SI) Pumps A and B, as documented in WOs 5291695 and 5295785 on October 18, 2023

Containment Isolation Valve (CIV) Testing (IP Section 03.01) (1 Sample)

(1)2BOSR 6.1.1-25; Unit 2 Primary Containment Type B Local Leak Rate Testing of Spare Containment Penetrations, as documented in WOs 5256840 and 5256841 on October 18, 2023

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Section 02.01-02.03) (1 Sample)

(1) The inspectors completed an evaluation of Emergency Action Level (EAL) and Emergency Plan changes on December 18, 2023. For the inspection period from July 01, 2022, through June 30, 2023, the licensee did not make any changes to the site Emergency Plan and EAL Bases/Matrix documents. The inspectors independently reviewed the current revisions of these documents to verify no changes were completed.

This evaluation does not constitute NRC approval.

71114.06 - Drill Evaluation

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

(1) Technical Support and Operations Support Centers Focus Area Drill Training on December 20,

RADIATION SAFETY

71124.01 - Radiological Hazard Assessment and Exposure Controls

Contamination and Radioactive Material Control (IP Section 03.03) (2 Samples)

The inspectors observed/evaluated the following licensee processes for monitoring and controlling contamination and radioactive material:

(1) Licensee surveys of potentially contaminated material leaving the radiologically controlled area (RCA) and workers exiting the RCA at Unit 2 Contractors Access Facility during a refueling outage

(2) Workers exiting the protected area through Whole Body Monitors at the Main Access Facility 1 during a refueling outage

71124.03 - In-Plant Airborne Radioactivity Control and Mitigation

Permanent Ventilation Systems (IP Section 03.01) (1 Sample)

The inspectors evaluated the configuration of the following permanently installed ventilation systems:

(1) Fuel Handling Building Exhaust Filter Ventilation System

Self-Contained Breathing Apparatus for Emergency Use (IP Section 03.04) (1 Sample)

(1) The inspectors evaluated the licensees use and maintenance of self-contained breathing apparatuses.

71124.04 - Occupational Dose Assessment

Source Term Characterization (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated licensee performance as it pertains to radioactive source term characterization.

External Dosimetry (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated how the licensee processes, stores, and uses external dosimetry.

Special Dosimetric Situations (IP Section 03.04) (2 Samples)

The inspectors evaluated the following special dosimetric situations:

(1) Declared Pregnant Worker - EID 086635 and 9775022

(2) Use of EDEX for RWP BY-2-23-00647 CRDM Inspections

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

MS10: Cooling Water Support Systems (IP Section 02.09)===

Main article: IP 71151

(1) Unit 1 (October 1, 2022 through September 30, 2023)

(2) Unit 2 (October 1, 2022 through September 30, 2023)

BI02: RCS Leak Rate Sample (IP Section 02.11) (2 Samples)

(1) Unit 1 (October 1, 2022 through September 30, 2023)

(2) Unit 2 (October 1, 2022 through September 30, 2023)

71152 A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)

Main article: IP 71152

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

(1) The inspectors performed a detailed review of various IRs pertaining to the process of scheduling, ordering, receipt, issuance, and installation of parts and equipment. An in-depth review of the barriers associated with this process flow was selected due to the inherent safety significance and quality control requirements associated with the procurement, acceptance, and use of safety related parts within the plant on December 13, 2023.

(2) The inspectors performed a detailed review of oil sample test results for each emergency diesel generator in response to recent operating experience with diesel lubricating oil contamination on December 19, 2023.

71152 S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)

Main article: IP 71152

(1) The inspectors reviewed the licensees corrective action program and other licensee trending programs for potential adverse trends that might be indicative of a more significant safety issue. The inspectors observed a potential trend in 0A Essential Service Water Makeup Pump trips as identified by the licensee in IR 4701152, Potential Trend in 0A Essential Service Water (SX) Makeup Pump Trips, on December 20,

INSPECTION RESULTS

Observation: Review of Oil Sample Test Results 71152A The inspectors performed a detailed review of oil sample test results in response to recent operating experience with diesel lubricating oil contamination as documented in IR 4718769, 2DG01KA (Prime Mover for the 2A Emergency Diesel Generator) Wear Metal Contamination.

Procedure MA-AA-716-230-1001, Oil Interpretation Guideline, identifies the alert range, for the Cooper Bessemer Diesels, for chromium, as > 5-10 ppm. The fault range for chromium is identified as > 10 ppm. The sample result dated November 3, 2023, indicated 13 ppm of chromium. An additional oil sample was subsequently taken and showed 7 ppm of chromium.

There is a scheduled work window for the 2DG01KA diesel in the spring of 2024. The licensee considered performing portions of this work early to address the potential concern with elevated chromium in the lubricating oil. Based on the additional oil sample test results, the license determined that it would be sufficient to monitor diesel performance, as this lower level of chromium is not expected to challenge the ability of the diesel to perform its function, until the scheduled work window arrives in the spring.

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: Review of the Process of Scheduling, Ordering, Receipt, Issuance, and Installation of Parts and Equipment 71152A The inspectors performed a detailed review of various IRs pertaining to the process of scheduling, ordering, receipt, issuance, and installation of parts and equipment. An in-depth review of the barriers associated with these processes was selected due to the inherent safety significance and quality control requirements associated with the procurement, acceptance, and use of safety related parts within the plant.

Procedure WC-AA-101-1002, Work Scheduling, provides a process overview of the online scheduling process including guidance for support groups that participate in the online scheduling process. SM-AA-102, Warehouse Operations, establishes the process for receipt, storage, and handling material, parts, and components through the stations warehouses. The inspectors used WC-AA-101-1002 and SM-AA-102 to determine what barriers exist to prevent incorrect equipment from being installed in plant applications, then compared these to 28 issues involving incorrect parts pulled from the corrective action program (CAP). The inspectors made several observations with regards to the IRs:

The most common themes documented under the why did the condition happen portion of the IR were errors in human performance and changes or substitutions made by the vendor without prior notification.

Nine of the 28 IRs identified instances where the issue with parts was discovered at the last barrier prior to improper installation - during the execution of the work.

Despite this, the assessment of like-for-like parts at the jobsite proved successful in identifying problems with parts and documenting them in the CAP. This barrier proved to be effective even during periods of increased maintenance activities, such as during outages.

An additional nine of the 28 IRs documented issues where incorrect parts were discovered to have already been installed in error without the physical changes being evaluated as required by procedure SM-AA-300-1002, Bill of Material Development and Right Parts Selection for Maintenance. Evaluations performed upon discovery determined the technical changes of the incorrect parts did not change the function of the part, nor impact component/system performance.

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: Semiannual Trend Review of IR 4701152, Potential Trend in 0A Essential Service Water (SX) Makeup Pump Trips 71152S The inspectors performed a detailed review of IRs and corrective actions associated with IR 4701152, Potential Trend in 0A Essential Service Water (SX) Makeup Pump Trips.

In short, this document identifies four trips of the 0A SX Makeup Pump that occurred between April of 2022, and September of 2023. The individual failures were documented in IRs: 4489594, 4490482, 4539770, 4687057, and 4701020.

In accordance with corrective action program requirements, the licensee performed extent of condition and cause reviews. Additionally, preventive maintenance activities and schedules were also reviewed for potential modification. Lastly, these events were reviewed for impact to licensee performance goals established as part of their Maintenance Rule program.

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 January 18, 2024, the inspectors presented the integrated inspection results to A. Schuerman, Plant Manager, and other members of the licensee staff.

On October 13, 2023, the inspectors presented the radiation protection inspection results to S. Leach, Radiation Protection Manager, and other members of the licensee staff.

On October 17, 2023, the inspectors presented the Inservice Inspection (ISI) Exit Meeting inspection results to P. Murray, Engineering Manager, and other members of the licensee staff.

On December 18, 2023, the inspectors presented the emergency preparedness inspection results to R. Pauley, Emergency Preparedness Manager, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

4698132

Install Thermal Covers on Empty HI Storms

08/23/2023

4713603

Heaters in MSIV Rebuild Building are Not Working

10/30/2023

4714534

DCS - Heaters Not Working in Dry Cask Storage Building

11/01/2023

4714554

1SH06AQ Fan Does Not Run

11/01/2023

4714555

0SH23AJ Fan Will Not Run and Needs Cleaning

11/01/2023

4714556

0SH23AN Fan Will Not Run and Needs Cleaning

11/01/2023

4714562

0SH23AR Fan Will Not Run

11/01/2023

4714563

0SH23AG Fan Will Not Run

11/01/2023

4714678

2SH15AB Fan Would Not Start. Winter Readiness

11/02/2023

4714679

2SH15AF Fan Would Not Start. Winter Readiness

11/02/2023

4714683

2SH15AH Fan Would Not Start. Winter Readiness

11/02/2023

4714684

2SH15AJ Fan Would Not Start. Winter Readiness

11/02/2023

4714686

2SH15AL Fan Would Not Start. Winter Readiness

11/02/2023

4714687

2SH15AS Fan Would Not Start. Winter Readiness

11/02/2023

4714688

2SH15AT Fan Would Not Start. Winter Readiness

11/02/2023

4714974

Dirty SH Heater

11/03/2023

4714976