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Nine-Month Supplemental Response to NRC Generic Letter 2008-01. Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems
	ML083290096
Person / Time
Site:	Grand Gulf
Issue date:	11/20/2008
From:	Krupa M; Entergy Operations
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GL-08-001, GNRO-2008/00068
	Download: ML083290096 (5)
	v • d • e

~Entergy Entergy Operations, Inc.

7003 Bald Hill Road PO. Box 756 Pori Gibson, MS 39150 Tel 601 437 6694 Michael A. Krupa Director

~'l.Jclear Safety Assurance November 20, 2008 GNRO-2oo8/oo068 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington. D.C. 20555-0001

Subject:

Nine-Month Supplemental Response to NRC Generic Letter 2008-01.

"Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal. and Containment Spray Systems" Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29

References:

1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling. Decay Heat Removal, and Containment Spray Systems" dated January 11, 2008 (GNRI 2008-00006).

2. Clarification of Commitment in Three Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling. Decay Heat Removal, and Containment Spray Systems" (GNRO 2008-00050) dated June 30, 2008

3. Nine-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling. Decay Heat Removal, and Containment Spray Systems" (GNRO 2008-00066) dated October 13, 2008

Dear Sir or Madam:

The Nuclear RegUlatory Commission (NRC) issued Generic Letter (GL) 2008-01 (Reference 1) to request that each licensee evaluate the licensing basis, design, testing, and corrective action programs for the Emergency Core Cooling Systems (ECCS).

Residual Heat Removal (RHR) system, and Containment Spray system, to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.

GNRO-2008/00068 Page 2 GL 2008-01 requested each licensee to submit a written response in accordance with 10 CFR 50.54(f) within nine months of the date of the GL to provide the information summarized below':

(a) A description of the results of evaluations that were performed pursuant to the requested actions; (b) A description of all corrective actions, including plant, programmatic, procedure, and licensing basis modifications that were determined to be necessary to assure compliance with the quality assurance criteria in Sections III, V, XI, XVI, and XVII of Appendix B to 10 CFR Part 50 and the licensing basis and operating license as those requirements apply to the subject systems; and, (c) A statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

Grand Gulf Nuclear Station (GGNS) provided a response to the items noted above in Reference 3. As committed to in Reference 2 GGNS has completed its assessments of the inaccessible drywell portions of these systems/functions during Refuel Outage 16. The attached supplemental response documents completion of that commitment.

The Attachment to this letter contains the GGNS nine-month supplemental response to NRC GL 2008-01.

There are no commitments contained in this submittal.

If you have any questions or require additional information regarding this matter, please contact Dennis Coulter at 601-437-6595.

I declare under penalty of perjury that the foregoing is true and correct. Executed on November 20, 2008.

Yours truly, MAKlDMC:dmc

Attachment:

Nine-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems.

cc: (See Next Page)

GNRO-2008/00068 Page 3 cc: NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 U. S. Nuclear Regulatory Commission AnN: Mr. Elmo E. Collins, Jr. (w/2)

Regional Administrator, Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 U.S. Nuclear Regulatory Commission AnN: Mr. Carl F. Lyon, NRR/ADRO/DORL (w/2)

ATTN: ADDRESSEE ONLY AnN: U.S. Postal Delivery Address Only Mail Stop OWFN/O-881 Washington, D.C. 20555-0001

Attachment to GNRO-2008/00068 Nine-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems"

Attachment to GNRO-2008/00068 Nine-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" This attachment contains the nine-month supplemental response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008.

This attachment provides additional information that was not available for the first nine-month response submitted on October 13, 2008 (GNRO 2008-00066). Specifically, drywell walk downs were not complete at the time the first response was submitted. Drywell walk downs are now complete. The results of the walk downs are provided in this supplemental response.

Section numbers below correspond to the section numbers submitted on October 13, 2008 (GNR02008-00066) Attachment 1. Only section numbers for updated sections are provided.

A. EVALUATION RESULTS 2 DESIGN EVALUATION 2.3 System Walkdowns The nine month response to Generic Letter 2008-01 was submitted on October 13, 2008. Due to inaccessibility, selected drywell piping walk-downs remained to be completed prior to the nine month due date. These remaining walk-downs were completed during Grand Gulf Refueling Outage 16.

Approximately 95% of High Pressure Core Spray (HPCS), 95% of Low Pressure Core Spray (LPCS), 50% of Residual Heat Removal (RHR) System Band 45% of RHR System C piping were visually inspected in the drywell. This visual inspection included selected high point vents and test connections.

Confirmatory visual inspections of selected portions of the HPCS, LPCS and RHR systems in the drywell determined that the actual piping runs, location of vent valves, and other components were as shown on the isometric drawings. The drywell inspections did not reveal any discrepancies between isometric drawings and installed piping. No corrective actions were identified.

RHR A was not inspected due to previously verified correlation between isometric drawings and piping installation outside the drywell and difficulty in accessing the piping inside the drywell.

Due to the verified accuracy of the isometric drawings, there is a high confidence level that the RHR A piping is installed as shown in these drawings.

5 CONCLUSION Based on the additional drywell walk-down evaluations completed and documented herein, GGNS concludes that the evaluated systems are in compliance with the current licensing basis, design basis, and applicable regulatory requirements and are operable. No corrective actions were identified from the drywell walk-downs.