ML15324A371

Prairie Island Nuclear Generating Plant, Units 1 and 2- Transmittal of U.S. Army Corps of Engineers Flood Hazard Reevaluation Information (Public)

ML15324A371
Person / Time
Site:	Prairie Island
Issue date:	11/18/2015
From:	Hall V E Japan Lessons-Learned Division
To:	Davison K K Northern States Power Co
HALL, VE
Shared Package
ml15296a361	List: ML15324A371
References
TAC MF3697, TAC MF3698
Download: ML15324A371 (4)

Text

OFFICIAL USE ONLY

- SECURITY-RELATED INFORMATION OFFICIAL USE ONLY

- SECURITY-RELATED INFORMATION

November 18, 2015 Mr. Kevin K. Davison Site Vice President Northern States Power Company - Minnesota Prairie Island Nuclear Generating Plant 1717 Wakonade Drive East Welch, MN 55089-9642

SUBJECT:

PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 - TRANSMITTAL OF U.S. ARMY CORPS OF ENGINEERS FLOOD HAZARD REEVALUATION INFORMATION (TAC NOS. MF3697 AND MF3698)

Dear Mr. Davison:

The purpose of this letter is to transmit the U.S. Army Corps of Engineers (USACE) portion of the Prairie Island Nuclear Generating Plant, Units 1 and 2 flood hazard reevaluation (FHR) associated with the assessment of flood hazards due to flooding in streams and rivers, including potential site flooding due to dam failure. By letters dated May 5, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML14065A112 and ML14064A291), Northern States Power Company - Minnesota (the licensee), doing business as Xcel Energy (Xcel), requested assistance from the U.S. Nuclear Regulatory Commission (NRC) in obtaining information from the USACE to support Xcel's development of a report documenting the FHR in response to the March 12, 2012, request for information (ADAMS Accession No. ML12073A348). The NRC staff held meetings to discuss the details of the information being provided by USACE with Xcel and the USACE on the following dates:

• August 5, 2014 (summary at ADAMS Accession No. ML14220A283)

• July 9, 2015 (summary at ADAMS Accession No. ML15271A207)

These meetings were closed to the public due to the discussion of security-related information.

Enclosures 2 and 3 to this letter contain the results of the USACE flood hazard reevaluation and is non-public for security-related information. Xcel needs to consider the USACE results for Prairie Island as part of its flood hazard reevaluation report, which is due to the NRC within 180 days of this letter (May 16, 2016). The information contained in the enclosures was developed in accordance with Japan Lessons-Learned Directorate (JLD) interim staff guidance (ISG) JLD-ISG-2013-01, "Interim Staff Guidance For Assessment of Flooding Hazards Due to Dam Failure," Revision 0, dated July 29, 2013 (ADAMS Accession No. ML13151A153), and on the USACE knowledge of the river system.

Enclosures two and three to this letter contain Security-Related Information. When separated from Enclosures two and three, this letter and Enclosure one are DECONTROLLED.

OFFICIAL USE ONLY

- SECURITY-RELATED INFORMATION

OFFICIAL USE ONLY

- SECURITY-RELATED INFORMATION If you have any questions, please contact me at (301) 415-2915 or by e-mail at Victor.Hall@nrc.gov.

Sincerely, /RA/

Victor Hall, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation

Docket Nos. 50-282 and 50-306

Enclosures:

1. Description of Information Requested and Transmitted 2. CD containing USACE FHR spreadsheets, plots, and GIS files 3. Hydrographs and Inundation Maps

cc w/o encls: Distribution via Listserv

Pkg: ML15296A361 Letter: ML15296A349 *via e-mail OFFICE NRR/JLD/JHMB/PM NRR/JLD/JHMB/LA NRR/JLD/JHMB/BC NAME VHall SLent MShams DATE 10/26/15 11/4/15 11/15/15 OFFICE NRO/DSEA/RHM1/BC NRR/JLD/JHMB/PM NAME CCook ARiveraVarona for* VHall DATE 11/2/15 11/18/15 OFFICIAL USE ONLY

- SECURITY-RELATED INFORMATION Enclosure 1 OFFICIAL USE ONLY - SECURITY-RELATED INFORMATION Licensee Requested Information for Prairie Island Nuclear Power Plant:

Licensee Requested Information USACE Provided Information -

Filename in Enclosure 2 Flow and Stage Hydrographs (River miles 902.7, 900.6, and 899.3) Appendix E - Hydrographs.pdf 1 Hydrographs - Excel Format.xls 1 Maximum flow velocities at four cross sections Max Water Surfaces and Depths.xls 1 GIS shapefile of all cross sections between river miles 902.7 and 894.4 Prairie Island RAS XS Locations 2 Maximum water surface elevation at all cross sections between river miles 902.7

and 894.4 Max Water Surfaces and Depths.xls 1 Average water depth (or top width and flow area) at each cross section between river miles 902.7 and 894.4 Max Water Surfaces and Depths.xls 1 GIS shapefile of limits of inundation between river miles 902.7 and 894.4 Prairie Island_Inundation 2 1 Monticello Nuclear Power Plant and Prairie Island Nuclear Power Plant information are provided in the same pdf file and Excel spreadsheets.

2 GIS files include files with .shp, .shx, .dbf, and .prj extensions.