ML24361A129
| ML24361A129 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/21/2025 |
| From: | Robert Kuntz NRC/NRR/DORL/LPL3 |
| To: | Rhoades D Constellation Energy Generation |
| Klett, AL | |
| References | |
| EPID L-2022-LLA-0140 | |
| Download: ML24361A129 (1) | |
Text
January 21, 2025 David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LIMERICK GENERATION STATION, UNITS 1 AND 2 - REGULATORY AUDIT REPORT ON THE EQUIPMENT QUALIFICATION PORTION OF LIMERICK DIGITAL INSTRUMENTATION AND CONTROLS LICENSE AMENDMENT REQUEST (EPID L-2022-LLA-0140)
Dear David Rhoades:
By letter dated September26, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22269A569, non-publicly available), as supplemented by letters dated August12,2022 (ML22224A149), November 29, 2022 (ML22333A817), February 8, 2023 (ML23039A141), February 15, 2023 (ML23046A266), March 30, 2023 (ML23089A324), April 5, 2023 (ML23095A223), May 23, 2023 (ML23143A342), June 26, 2023 (ML23177A224),
July 31, 2023 (ML23212B236), and January 26, 2024 (ML24026A296), Constellation Energy Generation, LLC (Constellation), submitted a license amendment request (LAR) for Limerick Generation Station, Units 1 and 2 (Limerick). The proposed amendment request would change both the design and technical specifications to permit the use of a new single digital instrumentation and controls system to replace analog instrumentation of reactor protection system, analog nuclear steam supply shutoff system, emergency core cooling system, reactor core isolation cooling system, and end-of-cycle recirculation pump trip at Limerick. In addition, the proposed amendments would change the classification of the redundant reactivity control system from safety-related to non-safety-related, eliminate the automatic redundant reactivity control system feedwater runback function, eliminate several surveillance requirements, and allow the use of automated operator aids (or automated controls) from main control room.
To assist in its review of the Limerick digital instrumentation and controls LAR, the U.S.
Nuclear Regulatory Commission staff conducted a regulatory audit on the equipment qualification (EQ) portion of the LAR between December 5 through 8, 2023, at the testing facility in New Stanton, Pennsylvania consistent with the audit plan issued September 7, 2023.
The scope of major EQ audit activities includes the environmental, electromagnetic compatibility, and Class 1E to non-1E isolation qualification. A summary of the activities completed during this audit are in the enclosed audit report.
If you have any questions, please contact me by telephone at 301-415-3733 or by email to robert.kuntz@nrc.gov.
Sincerely,
/RA/
Robert F. Kuntz., Senior Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and50-353
Enclosure:
Audit Report cc: Listserv
Enclosure AUDIT REPORT FOR EQUIPMENT QUALIFICATION PORTION OF DIGITAL INSTRUMENTATION AND CONTROLS LICENSE AMENDMENT REQUEST CONSTELLATION ENERGY GENERATION, LLC LIMERICK GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-352 AND 50-353
1.0 BACKGROUND
By letter dated September 26, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22269A569; non-publicly available), as supplemented by letters dated August 12, 2022 (ML22224A149), November 29, 2022 (ML22333A817), February 8, 2023 (ML23039A141), February 15, 2023 (ML23046A266), March 30, 2023 (ML23089A324), April 5, 2023 (ML23095A223), May 23, 2023 (ML23143A342), June 26, 2023 (ML23177A224), July 31, 2024 (ML23212B236), and January 26, 2024 (ML24026A296), Constellation Energy Generation, LLC (Constellation), submitted a license amendment request (LAR) for Limerick Generation Station, Units 1 and 2 (Limerick). The proposed amendment request would change both the design and technical specifications to permit the use of a new single digital instrumentation and controls (I&C) system to replace analog instrumentation of reactor protection system, analog nuclear steam supply shutoff system, emergency core cooling system, reactor core isolation cooling system, and end-of-cycle recirculation pump trip at Limerick. In addition, the proposed amendments would change the classification of the redundant reactivity control system from safety-related to non-safety-related, eliminate the automatic redundant reactivity control system feedwater runback function, eliminate several surveillance requirements, and allow the use of automated operator aids (or automated controls) from main control room.
To assist in its review of the Limerick digital I&C LAR, the U.S. Nuclear Regulatory Commission (NRC) staff conducted a regulatory audit on the equipment qualification (EQ) related information in the LAR to enable the NRC staff to gain understanding, verify information, and identify information that may be required to support a safety determination in its safety evaluation. The plan for this audit was issued by letter dated September 7, 2023 (ML23241A945).
2.0 AUDIT SCOPE AND ACTIVITIES The audit scope includes the environmental, EMC, and Class 1E to non-1E isolation qualifications of equipment to be installed in the Limerick main control room (MCR) and plant protection system (PPS) cabinets for the Limerick DMP.
During the audit, the NRC staff found out that the component interface module (CIM) system for the Limerick DMP was included as part of a representative PPS cabinet which was tested for the EQ. In addition, the licensee stated in the Licensing Technical Report (LTR) of the LAR that previous EQ records for the AP1000 CIM system were not credited for the Limerick DMP.
Therefore, the NRC staff did not audit previous AP1000 CIM EQ records although it was included in the audit plan.
The audit was started on December 5 and ended on December 8, 2023. The audit was conducted at the Westinghouse Electric Company LLC (Westinghouse) testing facility in New Stanton, PA. The audit commenced at 9:00 a.m. each day from December 5 (Tuesday) to December 8 (Friday), 2023, and concluded before noon on December 8, 2023.
During the audit entrance briefing, the NRC staff provided an overview of the audit plan and agenda for the audit. The NRC staff held debriefing on observations made each day with representatives from the licensee and its contractor, Westinghouse. During the exit briefing on December 8, 2023, the NRC staff and the licensee with its contractor, Westinghouse, went through the list of all observations made during the audit and associated action items. See Section 5.0 of this report for details.
Each day the NRC staff reviewed non-docketed testing plans, procedures, and some testing records related to the EQ for the Limerick DMP described in the LAR. The NRC staff also held discussions with representatives of Constellation and its contractor Westinghouse. In addition, on the afternoon of December 5, 2023, the NRC staff toured the testing facility and PPS test specimen cabinets EQ-1 and EQ-2 which were tested for qualification as the equipment under test (EUT) for the Limerick DMP. On the morning of December 7, 2023, the NRC staff observed some actual environmental testing and asked the Westinghouse testing technician to perform some simple safety function as sample checks.
3.0 DOCUMENTS AND OTHER MATERIAL REVIEWED The documents which were reviewed during the audit include:
EQ testing plans and procedures used for the Limerick DMP, which include test sequence, specified service conditions, margins, test levels, performance and environmental conditions, and general acceptance criteria.
o EQ-MR-13-GLIM, Rev. 0, Equipment Qualification Strategy and Plan for the Plant Protection System Upgrade, Westinghouse Electric Company LLC.
o WNA-TP-07423-GEN, Rev. 3, Mechanical Preconditioning Test Procedure for the Plant Protection System Equipment Qualification Subassemblies, Westinghouse Electric Company LLC.
o WNA-TP-07320-GEN, Rev. 1, Plant Protection System Upgrade Equipment Qualification Test Monitoring Procedure, Westinghouse Electric Company LLC.
o WNA-TP-07634-GEN, Rev. 0, Plant Protection System Upgrade Equipment Qualification Test Cabinet Acceptance Test Procedure, Westinghouse Electric Company LLC.
o WNA-TP-07651-GEN, Rev. 2, Plant Protection System Upgrade MCR Components Equipment Qualification Test Monitoring Procedure, Westinghouse Electric Company LLC.
o EQ-TP-517-GEN, Rev. 1, Generic Electromagnetic Compatibility Qualification Test Procedure to meet the Requirements of EPRI TR-102323, Revision 4, Westinghouse Electric Company LLC.
o EQ-TP-528-GEN, Rev. 1, U.S. NRC Regulatory Guide 1.180, Revision 2 Generic Electromagnetic Compatibility Qualification Test Procedure, Westinghouse Electric Company LLC.
o EQ-TP-542-GLIM, Rev. 0, Seismic Test Procedure for the Limerick Generating Station Main Control Room Components, Westinghouse Electric Company LLC.
o EQ-TP-538-GLIM, Rev. 0, Environmental Test Procedure for the Main Control Room Class 1E Components for Limerick Units 1&2, Westinghouse Electric Company LLC.
o EQ-TP-544-GLIM, Rev. 0, Seismic Test Procedure for the Limerick PPS Equipment Qualification Cabinets, Westinghouse Electric Company LLC.
o EQ-TP-547-GLIM, Rev. 0, Environmental Test Procedure for Limerick EQ Cabinet.
Testing records for EQ tests conducted, both summary and detailed, and associated documents.
o WNA-TR-06567-GEN, Rev. 0, Plant Protection System Upgrade Equipment Qualification Test Cabinet Preconditioning Test Report, Westinghouse Electric Company LLC.
o WNA-TR-06566-GEN, Rev. 1, Plant Protection System Upgrade Equipment Qualification Test Cabinet Acceptance Test Report, Westinghouse Electric Company LLC.
o WNA-TR-06618-GEN, Rev. 0, "Plant Protection System Upgrade Equipment Qualification Test Cabinet Seismic Functional Monitoring Test Report," Westinghouse Electric Company LLC.
o EQLR-522, Rev. 0, Electromagnetic Compatibility Report for the Plant Protection System Upgrade MCR Components. Scheduled for December 2023.
o EQLR-529, Rev. 0, Seismic Qualification Test Report for the Limerick Generating Station Main Control Room Components, Westinghouse Electric Company LLC.
o EQLR-536, Rev. 0, Environmental Test Report for the Main Control Room Class 1E Components for Limerick Units 1&2, Westinghouse Electric Company LLC.
o EQLR-544, Rev. 0, EMC Report for Limerick EQ Cabinets Scheduled for December 2023.
o JID 23-00364, Rev. 4, Seismic Report for Limerick EQ Cabinets, Clark Testing Laboratory.
o 00000-ICE-37764, Rev. 4, Summary Qualification Report of Hardware Testing for Common Q Applications, Westinghouse Electric Company LLC.
o EQLR-517, Rev. 0, Seismic Qualification Test Report for Flat Panel Display, Westinghouse Electric Company LLC.
o WCAP-16166-P SUPPLEMENT 1-E05, Rev. 5, Equipment Qualification Report for AC160 Platform - PC Node Box / Flat Panel Display System Components, Westinghouse Electric Company LLC.
o EQLR-470, Rev. 0, Mild Environment Test Report for the Core Protection Calculator System Equipment, Westinghouse Electric Company LLC.
o RITS: 78988, 78985, 78937, 78745, 78719, 78716, 78713, 78683, and 77994.
o CN-EQT-22-8, Rev. 1, Qualification Evaluation of Plant Protection System Equipment for Limerick Generating Station Units 1 and 2 Main Control Room, Westinghouse Electric Company LLC.
o CN-EQT-23-4, Rev. 1, Dynamic Similarity of the Plant Protection System Cabinets for the Digital Modernization Program at Limerick Units 1&2, Westinghouse Electric Company LLC.
o EQ-EV-386-GLIM, Rev. 3, Comparison of Equipment Qualification Hardware Testing for Common Q Applications to Limerick Requirements, Westinghouse Electric Company LLC.
o EQ-EV-402-GLIM, Rev. 0, Environmental Evaluation for the Plant Protection System (PPS) for Use in Limerick Units 1&2, Westinghouse Electric Company LLC.
Sample documentation that demonstrates the implementation of a suitable quality assurance program implemented at the licensees and its contractors facilities.
o WNA-PQ-00538-GLIM, Rev. 2, Limerick Generating Station Plant Protection System Digital Modernization Project Units 1&2 Project Quality Plan, Westinghouse Electric Company LLC.
o ISO 9001 certificate.
o 4500883285 (Clark Purchase Order).
Sample documents to show the certifications of accreditation and calibration for the EQ test equipment.
o Certificate of Calibration # 0011446009, Type T Thermocouple and Certificate of Calibration # 0011451691 for Temperature/Humidity meter.
o EMC test logs for the PPS cabinets.
Identification, description, and quantity of the samples to be tested including significant information, such as manufacturer, model(s), and serial numbers to uniquely identify the sample.
o Appendix A of Test Reports specifies Equipment Under Test.
o 10173D40 (ECO-23-00088-15), Rev. 4, Limerick PPS Equipment Qualification Cabinet Assembly Configurations, Westinghouse Electric Company LLC.
o WNA-MWO-22-00010, Rev. 10, Limerick PPS EQ, Westinghouse Electric Company LLC.
o WNA-TC-03406-GEN, Rev. 1, Test Configuration Record for EQT Limerick Cabinet Qualification Test Procedure Westinghouse Electric Company LLC.
Safety functions are tested by the test procedures.
o WNA-TS-00216-GEN, Rev. 2, Plant Protection System Upgrade Equipment Qualification Unit Configuration and Test Specification, Westinghouse Electric Company LLC.
o LTR-GIC-23-041, Rev. 0, Limerick PPS EQ Trip Time Response Soltec Datalogger File Evaluation by MATLAB Script and Excel Spreadsheet, Westinghouse Electric Company LLC.
o WNA-RL-07247-GLIM, Rev. 2, "Software Release Record for Limerick PPS EQ AC160 Software," Westinghouse Electric Company LLC.
o WNA-RL-07248-GLIM, Rev. 1, "Software Release Record for Limerick PPS EQ FPDS Software," Westinghouse Electric Company LLC.
o WNA-RL-06783-GEN, Rev. 0, Software Release Record for the Generation II-A PC Node Box and HSL Modem Equipment Qualification FPDS Software, Westinghouse Electric Company LLC.
o WNA-RL-06782-GEN, Rev. 0, Software Release Record for the Generation II-A PC Node Box and HSL Modem Equipment Qualification AC160 Software, Westinghouse Electric Company LLC.
Mounting, connection, and other interface requirements.
o 10173D40 (ECO-23-00088-15), Rev. 4, Limerick PPS Equipment Qualification Cabinet Assembly Configurations, Westinghouse Electric Company LLC.
o 10173D41 (ECO-23-00143-7), Rev. 2, LIMERICK PPS EQUIPMENT QUALIFICATION SUPPORT EQUIPMENT, Westinghouse Electric Company LLC.
o 10173D42 (ECO-22-00018-13), Rev. 0, Limerick EQ1 and EQ2 Cabling Configuration, Westinghouse Electric Company LLC.
o EQ-TP-542-GLIM, Rev. 0, Seismic Test Procedure for the Limerick Generating Station Main Control Room Components, Westinghouse Electric Company LLC.
o EQ-TP-544-GLIM, Rev. 0, Seismic Test Procedure for the Limerick PPS Equipment Qualification Cabinets, Westinghouse Electric Company LLC.
o EQLR-529, Rev. 0, Seismic Qualification Test Report for the Limerick Generating Station Main Control Room Components, Westinghouse Electric Company LLC.
o JID 23-00364, Rev. 4, Seismic Report for Limerick EQ Cabinets, Clark Testing Laboratory.
Sample training records for EQ technicians, engineers, and approvers.
o Per the NRC staffs request, Westinghouse provided internal training records for a few EQ technicians, engineers, and approvers who have been involved in the EQ for the Limerick DMP.
4.0 AUDIT OBSERVATIONS During the audit, the NRC staff made a few major observations, which are summarized below with their resolutions and responses provided by the licensee and its contractor Westinghouse during and after the audit.
In the EQ Summary Report EQ-QR-433-GLIM, Revision 2 and relevant documents, the NRC staff did not locate a complete list of components with manufacturer, model number, version, part number installed in the EQ test specimen cabinets EQ-1 and EQ-2. During the audit, the licensee and Westinghouse agreed to include such a list of components in revision 3 of EQ Summary Report EQ-QR-433-GLIM. However, the NRC staff found that EQ Summary Report EQ-QR-433-GLIM, Revision 3 submitted on January 26, 2024, still does not include a full list of critical components in EQ-1 and EQ-2 cabinets. This observation was addressed in a request for additional information (RAI) 10 provided by NRC email dated March 19, 2024 (ML24079A292). The licensee provided a response to RAI 10 in a letter dated May 3, 2024 (ML24124A043).
According to NRC-endorsed EPRI TR-107330, Section 6.3.6, Class 1E to non-1E isolation testing should be performed. The NRC staff found that the EQ testing summary report EQ-QR-433-GLIM, Rev. 2 does not include any isolation testing results. During the audit, the licensee and Westinghouse did not make any Class 1E to non-1E isolation testing results available for audit, although its related testing plan and procedure document were made available and audited. During the audit, the licensee and its contractor Westinghouse stated that isolation barrier test results would be provided after the barrier tests are completed.
The NRC staff found that EQ Summary Report EQ-QR-433-GLIM, Revision 3, which was submitted on January 26, 2024, still does not include any information related to Class 1E to non-1E isolation testing results. This observation was addressed in RAI 9 in the NRC staffs March 19, 2024, email. The licensee provided a response to RAI 9 in a letter dated May 3, 2024.
For the EMC and environmental qualification testing, the NRC staff found that the testing procedures do not require the functional testing during the EQ testing and only static functional tests at steady state conditions without stressors applied are required to be conducted before and after each test. This is not consistent with guidance in NRC-endorsed EPRI TR-107330. To address this observation, the licensee and Westinghouse created two corrective action program (CAP) issue reports IR-2023-12161 and IR-2023-12158 during the audit. The recently submitted EQ Summary Report EQ-QR-433-GLIM, Revision 3, states that the issues documented in these two CAP reports will be resolved as part of the hardware reconciliation process.
During the audit, the NRC staff found that the environmental testing profiles shown in Figure 6.6-1 of Test Procedure EQ-TP-547-GLIM, Rev. 0, for the PPS cabinets and Figure 6.6-1 of Test Procedure EQ-TP-538-GLIM, Rev. 0, for the MCR equipment are different from the environmental testing profile in Figure 4-4 of the NRC-endorsed EPRI TR-107330.
During the audit the licensee provided a response to this observation. The licensee offered that EPRI TR-107330 does provide generic requirements for qualification; however, this requirement is not invoked as a requirement in Limerick specification NE-402 or Westinghouse document EQ-MR-13-GLIM. Further, the licensee said that the environmental condition and method employed for Limerick PPS equipment is consistent with Common Q platform requirements and WCAP-8587 Rev 6-A which have been accepted by the NRC and is referenced in Section 1.1 of EQ-MR-13-GLIM. Therefore, the environmental conditions specified in the Westinghouse document EQ-TP-547-GLIM to test equipment (i.e., simulate abnormal environmental extremes separately) is acceptable and representative to demonstrate qualification of Limerick PPS equipment.
The NRC staff notes that environmental conditions used for the Limerick DMP and methods are consistent with Common Q platform requirements.
As required in Constellation (Exelon) Specification NE-402, Rev. 3, the maximum reactor protection system (RPS) response time from the change of state of a sensor input contact to and including the opening of the contacts on the main trip actuators (scram contacts) is less than 50 milliseconds. However, the NRC staff found that the EQ time response for the EUT time response Path 1 as shown in Figure 3.3.10-3-1 of WNA-TP-07634-GEN, Rev. 0 (PPS Upgrade EQ Test Cabinet Acceptance Test Procedure) is expected to be approximately 195 milliseconds. Its understood that the production RPS response time will not be the same as the EQ response time because of different algorithms. But the expected EQ response time is almost 4 times the required response time in the Specification NE-402 for the EQ test specimen cabinet which is representative of all production PPS cabinets.
As part of the audit the licensee provided a response to this observation. The licensee noted that the EQ system is a simplified representation of the entire Limerick PPS set of components. Acceptance criteria were established specifically for the EQ system configuration under test. The actual time response was measured. During EQ testing, three paths were measured continuously, with the Digital Inputs (DIs) started by a function generator cycling every 3 seconds.
The licensee further noted that the EQ testing evaluated the time response of the equipment that comprises the simplified fast trip path.The purpose of the EQ response time functional test is to provide reasonable assurance that the hardware components that make up the actual time response path continue to meet the response time values used in the Limerick Response Time Calculation (WNA-CN-00603-GLIM). The acceptance criteria of the EQ EUT are validated during EQ testing.
Additionally, the licensee stated that Westinghouse calculation WNA-CN-00603-GLIM, Rev. 2, documents the response time assumptions for the equipment that comprise various automatic scram functions of the PPS design and architecture. All calculated PPS system time response values will be validated during system integrated testing.
Further the licensee noted that response time was not measured during the static steady state functional testing. As a part of evaluation and reconciliation efforts that will be planned to address the CAP IR-2023-12161 Evaluate RT/ESF paths thru SCRAM and CIM relays for Limerick PPS EQ - CRA-2023-067, Westinghouse will review whether each active component in the safety-related time response circuits (e.g., relay, AC160 I/O module, processor module, CIM) has been considered to determine time response during the seismic, EMC, and environmental tests. If the review and evaluation determine that components were not included, additional analysis and/or testing will be performed as part of the reconciliation effort.
LTR Section 6.2.2.19 states that Constellation is developing a new Fiber Optic cable specification specific for the DMP. Its document number and title are NE-381, Nuclear Safety Related Specification for Fiber-Optic Instrumentation and Control System Cable.
This document will ensure the fiber optic cable used for the high-speed links (HSLs) meets the Limerick Generating Station site environmental qualification requirements.
This item is also plant specific action item #20 identified in the safety evaluation of the generic Common Q topical report, which states that: licensee implementing an application based upon the Common Q platform that utilizes fiber optic cables to connect HSLs between safety divisions shall ensure that all plant specific environmental qualification requirements for this cabling are met. None of the documents made available during the audit included any information on the qualification of the new Fiber Optic cable. This observation was addressed by RAI 14 provided by email dated March 19, 2024. The licensee provided a response to RAI 14 in a letter dated May 3, 2024.
5.0 LIST OF AUDIT PARTICIPANTS The following persons attended the whole or partial audit in person or virtually:
Name Affiliation Michael Marshall NRC Jack Zhao NRC James Berg Constellation Name Affiliation Ashley Rickey Constellation Gerald P. Segner Constellation Brian T. Devine Constellation Francis J. Mascitelli Constellation Mark Samselski Constellation Steven R. Hess Constellation Kenneth G. Lunz Westinghouse Stephen L. Packard Westinghouse Robert Beasley Westinghouse Warren R. Odess-Gillett Westinghouse Jason E. Mears Westinghouse Matthew A. Shakun Westinghouse Suresh Channarasappa Westinghouse Andrew V. Lutz Westinghouse Dominic Mocello Westinghouse Angela L. Zubroski Westinghouse Christopher D. Crefeld Westinghouse Dante Mincin Westinghouse Lynette Little Westinghouse Boyan A. Setchenski Westinghouse Daniel W. Martin Westinghouse Miguel A. Vallarta Westinghouse Donna McCloy Westinghouse
ML24361A129 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL1/LA NRR/DEX/EICB/BC NAME RKuntz KEntz FSacko DATE 12/20/2024 1/6/2025 1/13/2025 OFFICE NRR/DORL/LPL1/BC NRR/DORL/LPL3/PM NAME HGonzález RKuntz DATE 1/21/2025 1/21/2025