ML18166A187

NRR E-mail Capture - LaSalle 1 and 2, EPID-L-2018-LLR-0012, LAR CSCS, Request for Additional Information (RAI)

ML18166A187
Person / Time
Site:	LaSalle
Issue date:	06/14/2018
From:	Bhalchandra Vaidya Plant Licensing Branch III
To:	Gullott D Exelon Corp
References
L-2018-LLA-0012
Download: ML18166A187 (3)

Text

NRR-DMPSPEm Resource From: Vaidya, Bhalchandra Sent: Thursday, June 14, 2018 2:27 PM To: david.gullott@exeloncorp.com; Sprengel, Ryan:(GenCo-Nuc)

Subject:

LaSalle 1 and 2, EPID-L-2018-LLR-0012, LAR RE: CSCS, Request for Additional Information (RAI)

Subject:

LaSalle County Station, Units 1 and 2 - License Amendment Request for Temporary Extensions to Technical Specifications Supporting Maintenance on Portions of the Core Standby Cooling System.

EPID- L-2018-LLA-0012 (CAC NOS. 000976/05000373/ L-2018-LLA-0012, and 000976/05000374/ L-2018-LLA-0012)

Docket Nos. 50-373 and 50-374 David and Ryan, By application dated January 24, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18024A275), Exelon Generation Company, LLC (EGC), the licensee requested an amendment to Renewed Facility Operating License Nos. NPF-11 and NPF-18 for LaSalle County Station (LSCS), Units 1 and 2, respectively. The license amendment request (LAR) is related to temporary extensions to technical specifications supporting maintenance on portions of the core standby cooling system. The proposed changes modify Technical Specifications (TSs) 3.7.2, "Diesel Generator Cooling Water (DGCW) System," 3.8.1, "AC Sources-Operating" and the associated TS Bases. The proposed changes allow an extended period to install isolation valves to support replacing degraded Core Standby Cooling System piping.

The NRC staff has determined that additional information is necessary to complete its review regarding the requested amendment.

The NRC Staffs request for additional information (RAIs) are provided below:

========================================================

REQUEST FOR ADDITIONAL INFORMATION BY THE CONTAINMENT AND PLANT SYSTEMS BRANCH LICENSE AMENDMENT REQUEST FOR TEMPORARY EXTENSIONS TO TECHNICAL SPECIFICATIONS SUPPORTING MAINTENANCE ON PORTIONS OF THE CORE STANDBY COOLING SYSTEM EXELON GENERATION - LASALLE COUNTY STATION, UNITS 1 AND 2 DOCKET NOS. 50-373 and 50-374 EPID Number L-2018-LLA-0012 RAI- SCPB 1 Applicable Regulatory Requirements Appendix A, General Design Criteria for Nuclear Power Plants, to Title 10 of the Code of Federal Regulations (10 CFR)

Part 50, General Design Criterion (GDC) 2, Design bases for protection against natural phenomena, states:

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. The design bases for these structures, systems, and components shall reflect: (1)

Appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated, (2) appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena and (3) the importance of the safety functions to be performed.

10 CFR Part 50.36, "Technical specifications," establish the requirements related to the content of the TSs. Section 50.36(c)(2)(ii) states:

Limiting conditions for operation. Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.

Issue The licensee stated:

The portion of DGCW return piping to be replaced is directly connected to the lake and below normal cooling lake level, replacement will require isolation. Isolation will be accomplished by hot tapping, installing temporary line stops (stopples), and then installing new isolation valves.

1

The associated carbon steel piping surfaces and the nature of impurities in lake water could make leak tight seating of the stops difficult. Additionally, the hot tap hardware during the hot tap process would add temporary additional seismic weight and moment loads to the pipe and pipe joints.

Request for Additional Information a) Identify and discuss the possible impact on plant safety caused by expected leakage past the line stops.

b) What precautions will be needed and implemented to mitigate the effects of leakage?

c) Considering the added weight and moment of the hot tap hardware, what actions will be taken or analysis will be performed to ensure plant safety during a seismic event, including a seismic induced loss of offsite power?

d) Since the pipes to be replaced are not isolable and below lake level, what contingency plans are there to combat flooding caused by possible gross failure of line stops or pipe?

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Subsequent to the discussion with your staff on June 14, 2018, you have provided the confirmed date of response as COB July 16, 2018.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources.

If you have any questions, please contact me at (301) 415-3308.

Bhalchandra K. Vaidya Licensing Project Manager NRC/NRR/DORL/LPL3 (301)-415-3308 (O) bhalchandra.vaidya@nrc.gov 2

Hearing Identifier: NRR_DMPS Email Number: 418 Mail Envelope Properties (Bhalchandra.Vaidya@nrc.gov20180614142600)

Subject:

LaSalle 1 and 2, EPID-L-2018-LLR-0012, LAR RE: CSCS, Request for Additional Information (RAI)

Sent Date: 6/14/2018 2:26:57 PM Received Date: 6/14/2018 2:26:00 PM From: Vaidya, Bhalchandra Created By: Bhalchandra.Vaidya@nrc.gov Recipients:

"david.gullott@exeloncorp.com" <david.gullott@exeloncorp.com>

Tracking Status: None "Sprengel, Ryan:(GenCo-Nuc)" <Ryan.Sprengel@exeloncorp.com>

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 5407 6/14/2018 2:26:00 PM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: