ML23241A945

Generation Station, Units 1 and 2 Regulatory Audit Plan Supporting Review of the Equipment Qualification Portion of Limerick Digital Instrumentation and Controls License Amendment Request

ML23241A945
Person / Time
Site:	Limerick
Issue date:	09/27/2023
From:	Marshall M Plant Licensing Branch 1
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
Sreenivas V, NRR/DORL/LPLI, 415-2597
References
EPID L-2022-LLA-0140
Download: ML23241A945 (8)

Text

September 27, 2023 Mr. 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 PLAN SUPPORTING REVIEW OF THE EQUIPMENT QUALIFICATION PORTION OF LIMERICK DIGITAL INSTRUMENTATION AND CONTROLS LICENSE AMENDMENT REQUEST (EPID L-2022-LLA-0140)

Dear Mr. Rhoades:

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), and July 31, 2024 (ML23212B236), Constellation Energy Generation, LLC (Constellation), submitted license amendment requests (LARs) for Limerick Generation Station, Units 1 and 2. The proposed amendment requests 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 the automatic isolation function for the turbine enclosure main steam line tunnel temperature high indication, eliminate several surveillance requirements, and allow the use of automated operator aids (or automated controls) from main control room.

The U.S. Nuclear Regulatory Commission staff has determined that a regulatory audit is needed to assist in the review of the Limerick digital instrumentation and controls LAR. This audit will be focused on the equipment qualification portion of the LAR. The regulatory audit will be conducted between November 6 through November 9, 2023, at the testing facility in New Stanton, Pennsylvania. Additional details for the audit are in the enclosed audit plan.

D. Rhoades If you have any questions, please contact me by telephone at 301-415-2871 or by e-mail to michael.marshall@nrc.gov or Nick Smith by telephone at 301-415-2509 or by e-mail to nicholas.smith@nrc.gov.

Sincerely,

/RA/

Michael L. Marshall, Jr., Senior Project Manager Plant Licensing Branch 1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

Audit Plan cc: Listserv

AUDIT PLAN FOR EQUIPMENT QUALIFICATION PORTION OF LIMERICK 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), and July 31, 2024 (ML23212B236), Constellation Energy Generation, LLC (Constellation), submitted license amendment requests (LARs) for Limerick Generation Station, Units 1 and 2. The proposed amendment requests 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 the automatic isolation function for the turbine enclosure main steam line tunnel temperature high indication, eliminate several surveillance requirements, and allow the use of automated operator aids (or automated controls) from main control room.

The U.S. Nuclear Regulatory Commission (NRC) staff has determined that a regulatory audit is needed to assist in the review of the Limerick digital I&C LAR. This regulatory audit will 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 NRC staffs review of the equipment qualification (EQ) portion of the LAR covers the environmental, electromagnetic compatibility, seismic, and Class 1E to non-Class 1E isolation qualifications for the Limerick digital modernization projects as stated in the above LAR. The EQ is necessary to ensure safety-related equipment for the instrumentation and control system for the Limerick digital modernization projects meet design basis and performance requirements when the equipment Enclosure

is exposed to the normal and adverse environments associated with its location. The basic objectives of EQ for safety-related systems are to reduce the potential for common mode failure due to environmental, electromagnetic interference and radio frequency interference, seismic, and Class 1E to non-Class 1E isolation effects and to demonstrate that the safety-related equipment can perform its designated safety function during and after a design basis event.

2.0 REGULATORY AUDIT BASES A regulatory audit is a planned license activity that includes the examination and evaluation of primarily non-docketed information. The audit is conducted with the intent to gain understanding, to verify information, and to identify information that will require docketing to support the basis of a licensing or regulatory decision. Performing a regulatory audit is expected to assist the NRC staff in efficiently conducting its review and gaining insights to the licensees processes and procedures. Information that the NRC staff relies upon to make the safety determination must be submitted on the docket. This audit will be conducted in accordance with NRR Office Instruction LIC-111, Regulatory Audits, Revision 1, dated October 2019 (ML19226A274). This audit is being conducted to support the NRC staffs review of the Limerick digital I&C license amendment request. It should be noted that this audit is in addition to the open item audit conducted remotely.

Regulations relevant to the NRC staffs review of the EQ portion of the LAR include:

Appendix A, General Design Criterion (GDC) 2, Design bases for protection against natural phenomen of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, which states, in part, that structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions.

Appendix A, GDC 4, Environmental and Dynamic Effects Design Bases, of 10 CFR Part 50, which states, in part, that structures, systems, and components important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents.

For nuclear power plants with construction permits issued after January 1, 1971, but before May 13, 1999, Section 50.55a(h), Protection and safety systems, of 10 CFR Part 50, requires protection systems to meet the requirements in Institute of Electrical and Electronic Engineers (IEEE) Standard (Std) 279-1968, Proposed IEEE Criteria for Nuclear Power Plant Protection Systems, IEEE Std 279-1971, Criteria for Protection Systems for Nuclear Power Generating Stations, or the requirements in IEEE Std 603-1991, Criteria for Safety Systems for Nuclear Power Generating Stations, and the correction sheet dated January 30, 1995. Limerick received construction permits on May 19, 1974. IEEE Std 279-1971 is included in the licensing basis for Limerick, and as stated in the LAR will not change the Limerick licensing basis. Clause 4.4 of IEEE Std 279-1971, Equipment Qualification states that:

Type test data or reasonable engineering extrapolation based on test data shall be available to verify that protection system equipment shall meet, on a continuing basis, the performance requirements determined to be necessary for achieving the system requirements.

3.0 PURPOSE AND SCOPE The NRC staff will review non-docketed testing plans, procedures, and records related to the EQ for the digital modification described in the LAR. The audit scope includes the qualification of equipment to be installed in the main control room, plant protection system (PPS) cabinets, and previous EQ records for the component interface module (CIM) system credited in the LAR.

If needed, the NRC staff will discuss the overall EQ program and testing plans utilized by Constellation and its contractors (e.g., Westinghouse). The NRC staff will observe the testing facilities and testing activities associated with the digital equipment described in the LAR.

The regulatory guidance (RG) that the NRC staff plan to use for the audit activities are:

RG 1.100, Seismic Qualification of Electric and Mechanical Equipment for Nuclear Power Plants, which describes methods that the staff of the U.S. NRC considers acceptable for use in the seismic qualification of electrical and active mechanical equipment and the functional qualification of active mechanical equipment for nuclear power plants.

RG 1.180, Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems, endorses and includes guidance for conformance with Military Standard MIL-STD-461G, Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment, and International Electrotechnical Commission (IEC) 61000 series standards for evaluation of the impact of electromagnetic interference, radio frequency interference, an electrical fast transient, and electrical power surges on safety-related I&C systems.

RG 1.209, Guidelines for Environmental Qualification of Safety-Related Computer-Based Instrumentation and Control Systems in Nuclear Power Plants, which endorses IEEE Std 323, IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations, with enhancements and exceptions.

EPRI TR-107330, Generic Requirements Specification for Qualifying a Commercially Available PLC for Safety-Related Applications in Nuclear Power Plants as endorsed by the NRC presents a specification in the form of a set of requirements to be applied to the generic qualification of programmable logic controllers (PLCs) for application and modification to safety-related l&C systems in nuclear power plants. It is intended to provide a qualification envelope corresponding to a mild environment that should meet regulatory acceptance criteria for a wide range of plant-specific safety-related applications.

4.0 INFORMATION AND OTHER MATERIAL NECESSARY FOR THE REGULATORY AUDIT Please upload the following documentation by October 2, 2023, to the online portal being used by Constellation to support the ongoing open items audits:

o Constellation (Exelon) Document LS-0192, Revision 0, Dynamic Qualification Requirements for Control Room Panels, March 2, 1998.

o Westinghouse Document JID:2312-R, Revision 0, Seismic Test for the Westinghouse Electric Company Three (3) AP1000 PMS Pentair Cabinets, June 2013.

o Westinghouse Document, EQLR-232, Revision 0, Environmental Test Report for the AP1000 Protection and Safety Monitoring System and Nuclear Instrumentation System Auxiliary Panels, November 2012.

o Westinghouse Document EQ-QR-252-APP, Revision 0, AP1000 Plant Protection and Safety Monitoring System Pentair Cabinets Seismic Qualification Report, August 2013.

In addition, please upload the following documentation by October 2, 2023, to the online portal being used by Constellation to support the open items audit. If Constellation prefers, it can make hard copies of the documents available to the audit team upon request at the beginning of the audit, instead of uploading the documents to the online portal.

o All testing plans and procedures used for EQ.

o Testing records for EQ tests conducted, including any failures which might have occurred during the complete EQ testing process and the documentation that demonstrates the failures or deficiencies were corrected or resolved.

o Documentation to demonstrate the implementation of a suitable quality assurance program implemented at the licensees and its contractors facilities.

o Documents to show the Certifications of Accreditation and Calibration for the EQ test equipment.

o Test reports, both summary and detailed, produced by the licensee or its contractor Westinghouse.

o 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 Equipment safety function(s) to be demonstrated and qualified life objective.

o Mounting, connection, and other interface requirements.

o Test sequence.

o Specified service conditions and margins or test levels.

o Performance and environmental conditions to be measured, including measurement accuracy.

o Operating conditions and measurement sequence in detail, including monitoring requirements.

o General acceptance criteria (ultimate acceptance criteria are plant-specific based on application of the equipment).

o Maintenance and replacement during age conditioning, if required.

o Provisions for control of modifications during tests.

o Previous EQ testing records, detailed reports, and associated summary reports for the CIM and its related safety remote node controller, single width transition panel, and double width transition panel components which are proposed to be used for the new PPS.

5.0 AUDIT TEAM The members of the audit team are:

Jack Zhao, Senior Electronics (Digital I&C) Engineer, Audit Team Co-Leader Richard Stattel, Senior Electronics (Digital I&C) Engineer, Audit Team Co-Leader Michael Marshall, Senior Project Manager, Audit Team Member Nick Smith, Project Manager, Audit Team Member 6.0 LOGISTICS The audit will start on November 6 and end on November 9, 2023. The audit will be conducted at the Westinghouse testing facility in New Stanton, PA. The audit will commence at 9:00 a.m.

each day from November 6, 2023 (Monday), to November 9, 2023 (Thursday), and conclude by noon on November 9, 2023. If the audit team determines it has completed its audit activities sooner, then the audit schedule and its closeout will be adjusted. During the audit entrance briefing, the NRC staff will provide an overview of the audit plan and discuss the objectives for the audit. During the exit briefing, the NRC staff will provide a summary of the NRC audit and its observations made during the audit.

The audit team will not remove any non-docketed documents or other materials from the online portal or location of the audit. If the audit team identifies information that requires docketing to support the basis for a regulatory decision concerning the review of the Limerick digital I&C license amendment request, the NRC staff will use the request for additional information process.

Any changes in the audit logistics will be coordinated and communicated through the assigned NRC project managers.

7.0 SPECIAL REQUEST If available, please provide the audit team with a small, enclosed conference room or similar space for the audit teams use and access to guest wi-fi.

8.0 DELIVERABLES An audit summary, which may be public, will be prepared within 90 days of the completion of the audit. If the NRC staff identifies information during the audit that is needed to support its regulatory decision, the staff will issue requests for additional information to the licensee.

ML23241A945 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NRR/DEX/EICB/BC NAME MMarshall KZeleznock RStattel DATE 08/29/2023 08/30/2023 09/14/2023 OFFICE NRR/DORL/LPL1/BC NRR/DORL/LPL1/PM NAME HGonzález MMarshall DATE 09/19/2023 09/27/2023