ML17331B149

NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - Nsws One-Time LAR (CACs MG0242 and MG0243, EPID L-2017-LLA-0299)

ML17331B149
Person / Time
Site:	McGuire, Mcguire
Issue date:	11/21/2017
From:	Michael Mahoney Plant Licensing Branch II
To:	Hentz L Duke Energy Corp
References
L-2017-LLA-0299, MG0242, MG0243
Download: ML17331B149 (3)

Text

NRR-DMPSPEm Resource From: Mahoney, Michael Sent: Tuesday, November 21, 2017 11:39 AM To: 'Hentz, Lee A' Cc: Jeff Thomas (Jeff.Thomas@duke-energy.com)

Subject:

Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - NSWS One-Time LAR (CACs MG0242 and MG0243, EPID L-2017-LLA-0299)

Lee, By letter to the U.S. Nuclear Regulatory Commission (NRC) dated September 14, 2017 (Agencywide Documents Access Management System (ADAMS) Accession No. ML17262A090), Duke Energy, (the licensee), requested changes to the Technical Specifications (TSs) for McGuire Nuclear Station, Units 1 and 2 (McGuire). The proposed amendment will permit the 'A' Train NSWS to be inoperable for a total of 14 days to address a non-conforming condition on the 'A' Train supply piping from the Standby Nuclear Service Water Pond (SNSWP).

In order to complete its review, the U.S. Nuclear Regulatory Commission staff requests the following additional information. Please provide your response to the following requests for additional information (RAIs) within 30 days of the date of this correspondence.

RAI-01

McGuire described a defense-in-depth consideration where procedures and designated operators will be available to align the B Train Standby Nuclear Service Water Pond (SNSWP) suction path to the A Train Nuclear Service Water System (NSWS) pump suction following an earthquake that exceeds operating basis earthquake (OBE) or causes damage to the Cowans Ford Dam or low level intake (LLI) piping. These events would cause loss of the 1A and 2A NSWS pumps. McGuire further stated that if a failure of a B Train NSWS pump occurred subsequent to the events described above, an additional defense in depth contingency would be available, i.e. procedures and designated operators will be available to align the affected unit 'A' NSWS pump to the SNSWP via the shared 'B' NSWS piping to restore NSW flow to the affected unit.

McGuire has stated, in support of the contingency, the following conditions will be established before the start of activities in the LAR:

• The 'A' train supply header crossover valve (ORN-14A) will be opened prior to the evolution and power will be removed from the valve operator.

• 'B' train supply header crossover valve (ORN-15B) will be maintained closed with the ESFAS signal from each unit blocked prior to the evolution. Maintaining valve ORN-15B closed with power removed satisfies operability requirements for the 'B' Train NSWS. Valve ORN-15B can be opened from the control room after power is restored if conditions warrant the use of this contingency.

The NRC staff observed that until the A NSWS pumps could be realigned to the B NSWS header, the 1A and 2A diesel generators would not have required cooling. With the absence of cooling to the 1A and 2A diesel generators and the loss of off-site power caused by the seismic event, MOVs 0RN148A,C and 0RN147A,C and 0RN149A may not have power available, since these MOVs have emergency power from either the 1A or 2A diesel generator. Yet these MOVs have to be repositioned to align the A NSWS pumps to the B NSWS header as shown in Figures 6 and 7 of the LAR.

With loss of cooling to the 1A and 2A diesel generators causing the possible unavailability of these diesel generators, and the loss of offsite power caused by the seismic event:

1

a) Describe how the licensee will affect the lineup required by Figure 7 of the LAR, including repositioning MOVs 0RN148A,C and 0RN147A,C and 0RN149A, in order to supply the A NSWS pumps from the B NSWS header, which in turn would supply the 1A and 2A diesel generators.

b) With the loss of cooling to the 1A and 2A diesel generators during this event, discuss the effects on safety loads powered from the diesel generators and the effect on nuclear safety.

RAI-02

Figure 9, Personnel Access Manway, of the LAR, as presented in the original package provided to the NRC, is not legible.

Please provide a legible copy of Figure 9.

Once this email is added to ADAMS, I will provide the accession number for your reference.

Thanks Mike Michael Mahoney McGuire and Catawba Project Manager, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Desk: (301)-415-3867 Email: Michael.Mahoney@NRC.GOV 2

Hearing Identifier: NRR_DMPS Email Number: 3 Mail Envelope Properties (BL0PR0901MB2388C96D2E8657BC0891D5ABE5230)

Subject:

Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 -

NSWS One-Time LAR (CACs MG0242 and MG0243, EPID L-2017-LLA-0299)

Sent Date: 11/21/2017 11:39:18 AM Received Date: 11/21/2017 11:39:19 AM From: Mahoney, Michael Created By: Michael.Mahoney@nrc.gov Recipients:

"Jeff Thomas (Jeff.Thomas@duke-energy.com)" <Jeff.Thomas@duke-energy.com>

Tracking Status: None

"'Hentz, Lee A'" <Lee.Hentz@duke-energy.com>

Tracking Status: None Post Office: BL0PR0901MB2388.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 4058 11/21/2017 11:39:19 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

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