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Entergy Basis for Performance of the Mitigating Strategies Assessment with the Flood Hazard Information and Report for Recommendations 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident
	ML16088A025
Person / Time
Site:	Indian Point
Issue date:	03/21/2016
From:	Coyle L; Entergy Nuclear Northeast
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	NL-16-029
	Download: ML16088A025 (7)
	v • d • e

A Entergy Nuclear Northeast Indian Point Energy Center

~ Entergx 450 Broadway, GSB P.O. Box 249 Buchanan , NY 10511 -0249 Tel 914 254 6700 Lawrence Coyle Site Vice President NL-16-029 March 21 , 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11545 Rockville Pike, TWFN-2F1 Rockville , MD 20852-2738

SUBJECT:

Entergy Basis For Performance of the Mitigating Strategies Assessment with the Flood Hazard Information And Report For Recommendations 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident Indian Point Units 2 and 3 Docket Nos. 50-24 7 and 50-286 License Nos. DPR-26 and 64 REFERENCES : 1. Entergy Letter to NRC, NL-15-151 , "Entergy Submittal of Revision 1 to "Flood Hazard Re-evaluation - Combined Effect Floods - Coastal Processes" In Response to NRC Request for Information Pursuant to 10 CFR 50.54(f)

Regarding the Flooding Aspects of Recommendations 2.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," dated December 10, 2015.

2. FEMA, 2011 . FEMA P-55, Coastal Construction Manual: Principles and Practices of Planning , Siting , Designing , Constructing, and Maintaining Residential Buildings in Coastal Areas , 4th Edition , Federal Emergency Management Agency, 2011 . Available at http://www.fema.gov/media-library/assets/documents/3293.

3. ASCE , 2010. Minimum Design Loads for Buildings and Other Structures, ASCE Standard ASCE/SEI 7-10, American Society of Civil Engineers.

Dear Sir or Madam:

The purpose of this letter is to commit to perform the Flooding Hazard Mitigating Strategy Assessment (MSA) and report for Indian Point 2 and 3 using the combined effect flood determined by Reference 1.

Entergy will perform the MSA using the deterministic Probable Maximum Storm Surge (PMSS) of 150,000 cfs as discussed with the NRC staff in the audit of February 3 and 4 at NRC headquarters in Rockville Maryland . The results are a maximum stillwater elevation of 18.9 feet, NGVD29 at IPEC with coincident wave activity as discussed at the audit. Coincident wave activity is discussed below. NRC acceptance of this commitment will be included in the Mitigating Strategies Flood Hazard Information ftol/J tJ I- r--

NL-16-029 Docket Nos. 50-247 and 50-286 Page 2 of 2 (MSFHI) letter. This commitment is for the MSA at the site only and acceptance in the MSFHI letter does not change the Entergy position on the beyond design basis flooding applicable to the Indian Point site found in Reference 1 until such time as it changes .

The coincident wind-wave activity was calculated for wave crest and wave runup elevations at specific locations on the IPEC site during the controlling combined effects flood . Figure 1 of Attachment 1 presents the locations of five representative points for calculating wave action associated with the maximum stillwater elevation of 18.9 feet, NGVD29. Table 1 of Attachment 1 presents a summary of re-evaluated flood elevations at the locations shown on Figure 1.

The wave crest elevations at applicable locations at IPEC were based on deep water waves just off-shore of IPEC outboard of the river bulkhead that were calculated to have a height of 5.7 feet and a period of 4.2 seconds under conditions expected during the PMSS . These waves break at the river bulkhead thereby limiting the size of wave that can propagate across the inundated site area inboard of the bulkhead (per Reference 2 the maximum height in shallow water of the breaking wave is usually 78 percent of the stillwater depth). The wave form in shallow water is distorted so that the crest and trough are not equidistant from the stillwater level , with 70 percent of the wave height above the stillwater elevation. When an unbroken wave encounters a vertical wall , a reflected wave is formed and Reference 3 indicates that the crest of the reflected wave extends above the stillwater elevation by 120 percent of the depth (higher than the initiating wave) .

There are two new commitments contained in this submittal. If you have any questions regarding this confirmation of receipt, please contact Mr. Robert Walpole , Manager, Regulatory Assurance at (914) 254-6710.

Respectfully,

Attachment:

1. Calculated Water Elevations For Wind - Wave Activity Effects With a Figure Showing Wave Effect Locations

2. List of Regulatory Commitments cc: Mr. Douglas Pickett, Senior Project Manager, NRC NRR DORL Mr. Daniel H. Dorman, Regional Administrator, NRC Region 1 NRC Resident Inspector Mr. John B. Rhodes , President and CEO, NYSERDA Ms. Bridget Frymire, New York State Dept. of Public Service

ATTACHMENT 1 TO NL-16-029 CALCULATED WATER ELEVATIONS FOR WIND -WAVE ACTIVITY EFFECTS WITH A FIGURE SHOWING WAVE EFFECT LOCATIONS ENTERGY NUCLEAR OPERATIONS, INC.

INDIAN POINT NUCLEAR GENERATING UNIT NOS. 2 AND 3 DOCKET NOS. 50-247 AND 50-286

Attachment 1 NL-16-029 Docket Nos. 50-247 and 50-286 Page 1 of 2 Table 1: IPEC Hazard Evaluation Summary Table - River Flow of 150,000 cfs Mechanism Stillwater Wave Height I Reevaluated Figure Storm Surge Elevation Run up Hazard Location Evaluation 18.9ft 5.7 ft H.3 Combined Flood Event 21 .8 ft NGVD29 (Wave) A Riverward of U2 Intake NGVD29 Structure 18.9ft 3.9 ft H.3 Combined Flood Event 21.0 ft Between A and NGVD29 (Wave)

Landward of U2 Intake NGVD29 B Structure 18.9 ft 4.7 ft H.3 Combined Flood Event 23.6 ft NGVD29 (Runup) B Riverward of U2 Turbine NGVD29 Building 18.9ft Minimal 18.9ft H.3 Combined Flood Event NGVD29 NGVD29 c

East of U2 Turbine BuildinQ 18.9 ft 4 .7 ft H.3 Combined Flood Event 23.6 ft NGVD29 (Runup) D Riverward of U3 Turbine NGVD29 Building 18.9 ft H.3 Combined Flood Event minimal 18.9ft NGVD29 East of U3 Turbine Building NGVD29 E Note: Conservatively, only areas behind the turbine buildings have been designated as sheltered from waves . Other locations and systems may also be locally sheltered , partially or fully, by existing structures on the site. Examples include the Unit 2 intake pumps.

Attachment 1 NL-1 6-029 Docket Nos. 50-24 7 and 50-286 Page 2 of 2 Figure 1: Selected Point Locations (A through E) for Wave Calculation

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MCclllaur 1-aemtaut Unit 2 Intake Structure Condenstate Pol isher Bu ild ing Un it 3 Intake Structu re Admin istration Bu ild ing Note: All elevations references NGVD29.

0 50 100 200 300 400

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ATTACHMENT 2 TO NL-16-029 LIST OF REGULATORY COMMITMENTS ENTERGY NUCLEAR OPERATIONS, INC.

INDIAN POINT NUCLEAR GENERATING UNIT NOS. 2 AND 3 DOCKET NOS. 50-247 AND 50-286

Attachment 2 NL-16-029 Docket Nos. 50-247 and 50-286 Page 1 of 1 List of Regulatorv Commitments The following table identifies those actions committed to by Entergy in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

TYPE (Check One)

SCHEDULED COMMITMENT ONE- COMPLETION DATE CONTINUING TIME (If Required)

COMPLIANCE ACTION Entergy will perform the mitigating strategies assessment flooding at IPEC using maximum Stillwater of 18.9 feet, NGVD29 (reflecting PMSS of 150,000 cfs) [v") To be established and coincident wind-wave activity as documented in NL-16-029 subject to NRC concurrence in a MSFHI letter.

Provide NRC a report of MSA. [v") To be established