IR 05000352/2022003

Integrated Inspection Report 05000352/2022003 and 05000353/2022003

ML22311A062
Person / Time
Site:	Limerick
Issue date:	11/07/2022
From:	Jon Greives Division of Operating Reactors
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
References
IR 2022003
Download: ML22311A062 (1)

Text

November 7, 2022

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000352/2022003 AND 05000353/2022003

Dear David Rhoades:

On September 30, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Limerick Generating Station, Units 1 and 2. On October 18, 2022, the NRC inspectors discussed the results of this inspection with Matthew Bonanno, 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, Publ ic Inspections, Exemptions, Requests for Withholding.

Sincerely, Jonathan E. Greives, Chief Projects Branch 4 Division of Operating Reactor Safety

Docket Nos. 05000352 and 05000353 License Nos. NPF-39 and NPF-85

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000352 and 05000353

License Numbers: NPF-39 and NPF-85

Report Numbers: 05000352/2022003 and 05000353/2022003

Enterprise Identifier: I-2022-003- 0035

Licensee: Constellation Energy Generation, LLC

Facility: Limerick Generating Station, Units 1 and 2

Location: Sanatoga, PA 19464

Inspection Dates: July 1, 2022 to September 30, 2022

Inspectors: A. Ziedonis, Senior Resident Inspector D. Beacon, Resident Inspector L. Grimes, Resident Inspector J. Ambrosini, Senior Emergency Preparedness Inspect or S. Mercurio, Emergency Preparedness Inspector

Approved By: Jonathan E. Greives, Chief Projects Branch 4 Division of Operating Reactor Safety

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Limerick Generating Station, Units 1 and 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

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

Additional Tracking Items

None.

PLANT STATUS

Unit 1 began the inspection period at rated thermal power. On September 10, 2022, the unit was down-powered to approximately 65 percent thermal power for a control rod sequence exchange, 'B' reactor feed pump repairs, main condenser water box leak investigation, and turbine valve testing. The unit was returned to full power on September 12, 2022, and remained at or near rated thermal power for the remainder of the inspection period.

Unit 2 began the inspection period at rated thermal power and remained at or near rated thermal 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.

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' primary containment instrument gas (PCIG) following degraded compressor conditions on July 12, 2022

(2) Unit 1 D14 emergency diesel generator (EDG) following restoration from maintenance and during D11 EDG surveillance testing on August 1, 2022

(3) Unit common 201 safeguards transformer and vital power alignment during 101 safeguards transformer replacement on September 27 and 29, 2022

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 2 'A' and 'C residual heat removal (RHR) system trains on September 15, 2022

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) Unit 1 fire area 47, standby liquid control and general equipment areas with area fire panel non-functional due to smoke detector trouble condition on July 5, 2022

(2) Unit common fire area 25, auxiliary equipment room 542 with area fire panel non-functional due to heat detection trouble on July 15, 2022

(3) Unit common fire area 113, turbine enclosure 23-line and generator equipment area rooms on July 21, 2022

(4) Unit 2 fire areas 6 and 8, Unit 2 Class IE battery rooms on August 30, 2022

(5) Unit 2 fire area 56, reactor core isolation cooling pump room 179 on September 23, 2022

71111.06 - Flood Protection Measures

Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)

The inspectors evaluated internal flooding mitigation protections in the:

(1) Unit 2 reactor building core spray pump rooms on July 28, 2022

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 a Unit 1 post-summer load drop for rod sequence exchange, 'B' reactor feed pump repairs, main condenser water box leak investigation, and turbine valve testing on September 10, 2022

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated licensed operator training scenarios in the simulator on August 10, 2022

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, 21 EDG, following the identification of jacket water leakage on August 2, 2022

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1) Unit 1 risk assessment associated with the 'B' drywell chiller high vibrations on July 22, 2022

(2) Unit 1 planned action green risk during high-pressure coolant injection valve maintenance on August 10, 2022

(3) Unit 1 emergent risk assessment in response to a main generator exciter ground alarm on August 19, 2022

(4) Unit common risk-informed completion time assessment associated with the 101 safeguards transformer replacement on September 19 and 22, 2022

71111.15 - Operability Determinations and Functionality Assessments

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

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) Unit 1 D11 EDG voltage regulator during slow start test run on July 8, 2022

(2) Unit 2 'A' PCIG functionality following air leaks found on the PCIG compressor on July 11, 2022

(3) Unit 1 114C/124C non-safeguard load centers and adjustable speed drive following water intrusion on August 9, 2022

(4) Unit 1 'A' low-pressure coolant injection following discovery of a drain valve leak on August 31, 2022

(5) Unit 1 hardened containment vent system following discovery of elevated pressure indication in argon purge header on September 29, 2022

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)

The inspectors evaluated the following temporary or permanent modifications:

(1) Unit common 101 safeguard transformer replacement during the week of September 26, 2022

Severe Accident Management Guidelines (SAMG) Update (IP Section 03.03) (1 Sample)

(1) The inspectors verified the Site Severe Accident Management Guidelines were updated to incorporate the most recent revisions of the boiling water reactor (BWR)owners group Generic Severe Accident Technical Guidelines, and validated in accordance with Nuclear Energy Institute 14-01, Emergency Response Procedures and Guidelines for Beyond Design Basis Events and Severe Accidents, Revision 1 on July 14, 2022

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated the following post-maintenance testing activities to verify system operability and/or functionality:

(1) Unit 2 'B' PCIG capacity check post-maintenance testing following degraded gas compressor on July 12, 2022

(2) Unit 1 'D' RHR pump, valve and flow test following oil cooler maintenance on July 13, 2022

(3) Unit 2 D21 EDG following repair of a jacket water leak on August 3, 2022

(4) Unit 2 D24 EDG following 8-year preventive maintenance window on September 14 and 15, 2022

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance testing activities to verify system operability and/or functionality:

Surveillance Tests (other) (IP Section 03.01) (2 Samples)

(1) ST-6-092-113-1, Unit 1 D13 EDG 24-hour endurance test on July 6 and 7, 2022

(2) ST-6-051-232-1, Unit 1 'B' RHR system pump, valve, and flow test on September 26, 2022

Inservice Testing (IP Section 03.01) (1 Sample)

(1) ST-6-052-232-1, Unit 1 'B' loop core spray pump, valve, and flow test on August 11, 2022

71114.02 - Alert and Notification System Testing

Inspection Review (IP Section 02.01-02.04) (1 Sample)

(1) The inspectors evaluated Constellation's maintenance and testing of the alert and notification system on September 19 through September 22, 2022, for the period of September 2020 through August 2022

71114.03 - Emergency Response Organization Staffing and Augmentation System

Inspection Review (IP Section 02.01-02.02) (1 Sample)

(1) The inspectors evaluated the readiness of the Constellation's Emergency Preparedness Organization on September 19 through September 22, 2022

71114.04 - Emergency Action Level and Emergency Plan Changes

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

(1) The inspectors evaluated the following submitted Emergency Action Level and Emergency Plan changes.

• 21-20, EP-AA-1008, Addendum 3, Emergency Action Levels for Limerick Generating Station, Revision 6

• 21-63, EP-AA-1008, Addendum 3, Emergency Action Levels for Limerick Generating Station, Revision 7

This evaluation does not constitute NRC approval.

71114.05 - Maintenance of Emergency Preparedness

Inspection Review (IP Section 02.01 - 02.11) (1 Sample)

(1) The inspectors evaluated Constellation's maintenance and testing of the emergency preparedness program on September 19 through September 22, 2022, for the period of September 2020 through August

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 02.01)===

(1) Unit 1 for the period of July 1, 2021 through June 30, 2022

(2) Unit 2 for the period of July 1, 2021 through June 30, 2022

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)

(1) Unit 1 for the period of July 1, 2021 through June 30, 2022

(2) Unit 2 for the period of July 1, 2021 through June 30, 2022

MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)

(1) Unit 1 for the period of July 1, 2021 through June 30, 2022

(2) Unit 2 for the period of July 1, 2021 through June 30, 2022

EP01: Drill/Exercise Performance (DEP) Sample (IP Section 02.12) (1 Sample)

(1) November 1, 2021 through June 30, 2022

EP02: Emergency Response Organization (ERO) Drill Participation (IP Section 02.13) (1 Sample)

(1) November 1, 2021 through June 30, 2022 EP03: Alert And Notification System (ANS) Reliability Sample (IP Section 02.14) (1 Sample)

(1) November 1, 2021 through June 30,

INSPECTION RESULTS

No findings were identified.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On October 18, 2022, the inspectors presented the integrated inspection results to Matthew Bonanno, Plant Manager, and other members of the licensee staff.

• On September 22, 2022, the inspectors presented the Emergency Preparedness program inspection results to Mike Gillin, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.11Q Corrective Action IR 4520692 Unit 1 Rx conductivity in AL 1 09/04/2022

Documents IR 4521231 Water leak from 1B Reactor Feed Pump RV-06-115 09/07/2022

IR 4521279 U1 CDI Conductivity Above Chem Action Level 1 09/08/2022

IR 4521466 Unit 1 Rx chloride above goal 09/09/2022

IR 4522991 Pumping of Circ Water led to Exhaustion of Floor Drain D/B 09/16/2022

IR 4529398 U1 Post Summer Load Drop Reactor Engineering Critique 10/14/2022

71111.13 Corrective Action IR 4524015 Emergent work impacts for WW2238/2239 09/22/2022

Documents IR 4524223 Gaps identified in 101 transformer Project preparation 09/23/2022

IR 4525624 APS: Stop work entered 09/29/2022

IR 4526151 101 Transformer High Voltage Cable Damage in 544 10/01/2022

breaker

IR 4526182 101 Tap Changer indication is not Correct 10/01/2022

IR 4527341 Configuration control pre-cursor issue on 101 Trans 10/06/2022

IR 4530274 Issues Identified During 101 Transformer Replacement 10/18/2022

Miscellaneous OP-AA-108-118 101 transformer RICT final Revision 1

71111.18 Engineering EC 628883 101 safeguards transformer replacement

Changes

71114.02 Miscellaneous Limerick Generating Station (LGS) Public Alert and Revision 3

Notification System Design Report

71114.05 Miscellaneous EP-AA-1000 Exelon Nuclear Standardized Radiological Emergency Plan Revision 33

EP-AA-1008 Exelon Nuclear Radiological Emergency Plan Annex for Revision 32

Limerick Generating Station

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