GNRO-2011/00074, Supplemental Information Regarding Extended Power Uprate

Supplemental Information Regarding Extended Power Uprate

ML112420169
Person / Time
Site:	Grand Gulf
Issue date:	08/30/2011
From:	Krupa M Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2011/00074
Download: ML112420169 (5)

Text

Entergy Operations, Inc.

P. O. Box 756 Port Gibson, MS 39150 Michael A. Krupa Director, Extended Power Uprate Grand Gulf Nuclear Station Tel. (601) 437-6684 GNRO-2011/00074 August 30, 2011 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Supplemental Information Regarding Extended Power Uprate Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29

REFERENCES:

1. License Amendment Request, Extended Power Uprate, dated September 8, 2010 (GNRO-2010/00056, NRC ADAMS Accession No. ML102660403)

2. Response to Request for Additional Information Regarding Extended Power Uprate - Electrical Branch, dated May 5, 2011 (NRC ADAMS Accession No. ML111250552)

Dear Sir or Madam:

By letter Grand Gulf Nuclear Station, Unit 1 (GGNS) submitted an Extended Power Uprate (EPU) License Amendment Request (LAR) (Reference 1). The environmental qualification (EQ) accident temperature profiles for all plant EQ zones and elevations were provided as Figure 2.3-1 of LAR Attachment 5, Safety Analysis Report for Grand Gulf Nuclear Station. On July 29, 2011, an error was identified associated with the drywell accident temperature profiles reflected in Revision 6 of the design specification Environmental Parameters for GGNS (E100.0). The error, which was documented in the GGNS corrective action program, occurred in 2008 when E100.0 Revision 6 was developed; the curve set for the drywell accident temperature profile was inadvertently changed. This profile had been used in the EPU evaluation. A copy of the corrected curve is included in Attachment 1.

As a result of this error, a review of the EQ information contained in EPU LAR Attachment 5 and the responses to the Electrical Branch questions (Reference 2) has been performed. Based on this review, Entergy has determined two aspects of the EQ-related information are affected by this error:

1. The description of the post-LOCA temperature profile provided in EPU LAR Attachment 5, Section 3.2.1, Environmental Qualification of Electrical Equipment, in

GNRO-2011/00074 Page 2 of 3 the subsection titled Inside Containment is incorrect. A similar discussion was included in the response to questions 1 and 2 from the Electrical Branch (Reference 2).

2. The revised CLTP drywell EQ accident temperature profile used for qualification of equipment does not bound the EPU drywell enveloping accident temperature profile.

However, based on a review of the 37 EQ data packages associated with the components in the drywell using the revised EPU drywell curve, the evaluation results presented in EPU LAR (including EPU LAR Tables 2.3-1 and 2.3-2) are not affected. In addition, the conclusions, other than the characteristics of the curves, to the responses to the Electrical Branch EQ related questions (Reference 2) are unaffected by the revised curves.

No change is needed to the no significant hazards consideration included in the initial EPU LAR (Reference 1) as a result of the additional information provided. There are no new commitments included in this letter.

If you have any questions or require additional information, please contact Jerry Burford at 601-368-5755.

I declare under penalty of perjury that the foregoing is true and correct. Executed on August 30, 2011.

Sincerely, MAK/FGB/dm Attachments:

1. Revised EPU LAR Attachment 5 Figure 2.3-1

GNRO-2011/00074 Page 3 of 3 cc: Mr. Elmo E. Collins, Jr.

Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 East Lamar Blvd., Suite 400 Arlington, TX 76011-4005 U. S. Nuclear Regulatory Commission ATTN: Mr. A. B. Wang, NRR/DORL (w/2)

ATTN: ADDRESSEE ONLY ATTN: Courier Delivery Only Mail Stop OWFN/8 B1 11555 Rockville Pike Rockville, MD 20852-2378 State Health Officer Mississippi Department of Health P. O. Box 1700 Jackson, MS 39215-1700 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150

Attachment 1 GNRO-2011/00074 Grand Gulf Nuclear Station Extended Power Uprate Revised EPU LAR Attachment 5 Figure 2.3-1 to GNRO 2011/00074 Page 1 of 1 Revised EPU LAR Attachment 5 Figure 2.3-1 Worst Case EQ Enveloping Accident Temperature Profiles (All Plant EQ Zones and Elevations) 340 320 300 280 260 240 220 TEMPERATURE (°F) 200 180 160 140 120 100 80 1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06 1.00E+07 TIME (SECONDS)

CLTP DRYWELL EPU DRYWELL CLTP AUXILIARY BUILDING ENVELOPING EPU AUXILIARY BUILDING ENVELOPING CLTP AND EPU CONTAINMENT ENVELOPING (OUTSIDE DRYWELL)