ML19022A029

NRR E-mail Capture - Draft Request for Additional Information for LaSalle License Amendment Request to Adopt TSTF-334-A, Revision 2

ML19022A029
Person / Time
Site:	LaSalle
Issue date:	12/13/2018
From:	Kimberly Green Plant Licensing Branch III
To:	Sprengel R Exelon Generation Co
References
Download: ML19022A029 (4)

Text

NRR-DMPSPEm Resource From: Green, Kimberly Sent: Thursday, December 13, 2018 8:31 AM To: Sprengel, Ryan:(GenCo-Nuc)

Subject:

Draft Request for Additional Information for LaSalle License Amendment Request to Adopt TSTF-334-A, Revision 2 Attachments: LaSalle Draft RAI for TSTF-334 - CLEAN.docx

Dear Mr. Sprengel:

By letter dated February 7, 2018, Exelon Generation Company, LLC (EGC) requested a revision to the LaSalle County Station, Units 1 and 2, Technical Specifications to adopt Technical Specification Task Force (TSTF)

Traveler TSTF-334-A, Revision 2, Relaxed Surveillance Frequency for Excess Flow Check Valve Testing, dated October 31, 2000 (Agencywide Documents Access and Management System Package Accession No. ML18152A922). The proposed change would revise the number of excess flow check valves tested by Surveillance Requirement 3.6.1.3.8 from each to a representative sample.

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has identified an area where additional information is needed to complete its review. Attached, please find a draft request for additional information (RAI).

The draft RAI is being sent to ensure that the request is understandable and the regulatory basis for the request is clear. This email and the attachment do not convey or represent an NRC staff position regarding EGC's request.

Please let me know if EGC needs a call to clarify the NRC staffs request.

Kimberly Green (301) 415-1627 kimberly.green@nrc.gov 1

Hearing Identifier: NRR_DMPS Email Number: 765 Mail Envelope Properties (BL0PR0901MB241976385E00E0732BB7C6878FA00)

Subject:

Draft Request for Additional Information for LaSalle License Amendment Request to Adopt TSTF-334-A, Revision 2 Sent Date: 12/13/2018 8:30:54 AM Received Date: 12/13/2018 8:30:00 AM From: Green, Kimberly Created By: Kimberly.Green@nrc.gov Recipients:

"Sprengel, Ryan:(GenCo-Nuc)" <Ryan.Sprengel@exeloncorp.com>

Tracking Status: None Post Office: BL0PR0901MB2419.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1257 12/13/2018 8:30:00 AM LaSalle Draft RAI for TSTF-334 - CLEAN.docx 30695 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

DRAFT REQUEST FOR ADDITIONAL INFORMATION FOR LASALLE COUNTY STATION, UNITS 1 AND 2 AMENDMENT REQUEST TO REVISE SURVEILLANCE REQUIREMENT 3.6.1.3.8 By letter dated February 7, 2018, Exelon Generation Company, LLC (EGC) requested a revision to the LaSalle County Station, Units 1 and 2 (LSCS), Technical Specifications to adopt Technical Specification Task Force (TSTF) Traveler TSTF-334-A, Revision 2, Relaxed Surveillance Frequency for Excess Flow Check Valve Testing, dated October 31, 2000 (Agencywide Documents Access and Management System Package Accession No. ML18152A922). The proposed change would revise the number of excess flow check valves tested by Surveillance Requirement 3.6.1.3.8 from each to a representative sample.

RAI EICB-1:

The LSCS updated final safety analysis report (UFSAR) indicates that the excess flow check valves (EFCVs) at LSCS are equipped with position status indication lights that appear to comply with the guidance of Regulatory Guide (RG) 1.11, Instrument Lines Penetrating Primary Reactor Containment, Revision 0, and the requirements of Section 4.20 of IEEE Std. 279-1971, Criteria for Protection Systems for Nuclear Power Generating Stations. The EFCV position status indication function provides timely information to the operator on the status of the plant protection functions. An EFCV in the closed status may indicate that the reactor protection and engineered safeguards instruments connected to that line may not be reliably performing due to an instrument line breach.

The LSCS UFSAR, Appendix B, also indicates that the design of the instrument sensing lines that penetrate or connect to the primary containment are designed to strict penetration requirements, and that the provisions of RG 1.11 are incorporated into the design of the instrument sensing lines that penetrate or connect the primary containment at LSCS.

Furthermore, the UFSAR states that the design of these lines complies with the guidance in RG 1.11. The RG 1.11 states that sensing lines connected to instruments that are part of the protection system are extensions of that system and should satisfy the requirements for redundancy, independence, and testability for the protection system, to assure that the protective function will be accomplished. The RG also states that the status (opened or closed) of all such isolation valves should be indicated in the control room, and that without such an indication, a valve may be closed and the effectiveness of the instrument impaired for long periods of time. In addition, Section 4.20 of IEEE Standard 279-1971, which is the design basis for LaSalles protection system, states: The protection system shall be designed to provide the operator with accurate, complete, and timely information pertinent to its own status and to generating station safety. The design shall minimize the development of conditions which could cause meters, annunciators, recorders, alarms, etc., to give anomalous indications confusing to the operator.

A request for relief from the requirements of ASME OM Code ISTC-3522 and ISTC-3700 for the EFCV was submitted with the LAR. In this request the licensee indicates that if the proposed request is approved, the remote position status capability associated with the ECFVs would be verified to be accurate at the same frequency as the sampling program for ECFVs, which would be equivalent of each remote position status indicator being verified once per 10 years. The

staff recognizes that position/limit switch contacts that are idle for multiple years have experienced known failure mechanisms, such as sticking-in-place and mis-positioning.

Therefore, such electric circuits are usually tested periodically, such as quarterly.

Please justify that a reduced surveillance interval, equivalent to once-per-10-years, is adequate to verify the reliability of the EFCV position status indication function given potential failure modes experienced with position/limit switch indicators.

Alternatively, describe the approach or method that would be used to demonstrate the ability of operators to timely identify when an EFCV may be in its closed (checked) status without the functionality of the EFCV position status indicators. The description should discuss the relative timeliness of alerting operators to a potential problem in the instrument sensing line, impacting the functionality of the plant protection systems, in comparison to the use of EFCV position status indications.