IR 05000413/2007012

IR 05000413-07-012, and IR 05000414-06-012, Duke Energy Carolinas, LLC, NRC Final Significance Determination and Closure of Unresolved Item - Report

ML070800461
Person / Time
Site:	Catawba
Issue date:	03/21/2007
From:	Moorman J NRC/RGN-II/DRP/RPB1
To:	Morris J Duke Energy Carolinas, Duke Power Co
References
IR-06-012, IR-07-012
Download: ML070800461 (5)

Text

rch 21, 2007

SUBJECT:

CATAWBA NUCLEAR STATION - NRC FINAL SIGNIFICANCE DETERMINATION AND CLOSURE OF UNRESOLVED ITEM - REPORT 05000413/2007012 AND 05000414/2006012

Dear Mr. Morris:

On December 6, 2006, the U.S. Nuclear Regulatory Commission (NRC) completed a Special Inspection at your Catawba Nuclear Station Units 1 and 2 related to flooding vulnerabilities of the turbine building and some safety-related areas. The results of this inspection were documented in NRC Special Inspection Report 05000413/2006010 and 05000414/2006010.

This report contained Unresolved Item 05000413,414/2006010-01.

This unresolved item was opened to re-quantify the risk for a Green non-cited violation (NCV 05000413,414/2006004-02) issued on October 26, 2006. This NCV documented your failure to maintain appropriate design control to ensure that below-grade electrical conduits were properly sealed to prevent water intrusion into areas of the plant containing safety-related equipment.

The NRC Special Inspection identified that additional flooding vulnerabilities were present from April 6, 2005 to May 22, 2006, and determined that a requantification of the station risk was appropriate.

The NRC staff has completed requantification of the station risk for this issue and determined that the change to core damage frequency that resulted from the additional water ingress paths was less than 1E-6 (Green) because of the low frequency of rainfall events with the potential to flood the susceptible areas. Therefore, the risk significance of this issue, which was dispositioned as Green NCV 05000413/2006004-02, 05000414/2006004-02, will not change.

Thank you for your assistance in this matter. If you have any questions concerning this matter, please contact me at (404) 562-4647.

DPC 2 In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Web site at www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

James H. Moorman, III, Chief Reactor Projects Branch 1 Division of Reactor Projects Docket Nos.: 50-413, 50-414 License Nos.: NPF-35, NPF-52 cc: (See page 3)

_________________________

OFFICE RII:DRP RII:DRP SIGNATURE RHB /RA/ JHM /RA/

NAME RBernhard JMoorman DATE 03/21/2007 03/21/2007 E-MAIL COPY? YES NO YES NO YES NO YES NO YES NO YES NO YES NO

DPC 3 cc: North Carolina Electric Randy D. Hart Membership Corporation Regulatory Compliance Manager Electronic Mail Distribution Duke Power Company LLC d/b/a/Duke Energy Carolinas, LLC Peggy Force Electronic Mail Distribution Assistant Attorney General N. C. Department of Justice Lisa F. Vaughn Electronic Mail Distribution Associate General Counsel and Managing Attorney County Manager of York County, SC Duke Energy Corporation Electronic Mail Distribution 526 South Church Street-EC 07H Charlotte, NC 28202 Piedmont Municipal Power Agency Electronic Mail Distribution Kathryn B. Nolan Senior Counsel R. L. Gill, Jr., Manager Duke Energy Corporation Nuclear Regulatory Issues 526 South Church Street-EC 07H and Industry Affairs Charlotte, NC 28202 Duke Power Company LLC d/b/a Duke Energy Carolinas, LLC David A. Repka 526 S. Church Street Winston & Strawn LLP Charlotte, NC 28201-0006 Electronic Mail Distribution Distribution: (See page 4)

North Carolina MPA-1 Electronic Mail Distribution Henry J. Porter, Asst. Director Div. of Radioactive Waste Mgmt.

S. C. Department of Health and Environmental Control Electronic Mail Distribution R. Mike Gandy Division of Radioactive Waste Mgmt.

S. C. Department of Health and Environmental Control Electronic Mail Distribution Elizabeth McMahon Assistant Attorney General S. C. Attorney General's Office Electronic Mail Distribution Vanessa Quinn Federal Emergency Management Agency Electronic Mail Distribution

DPC 4 Letter to J. from James Moorman, III dated March 21, 2007 SUBJECT: CATAWBA NUCLEAR STATION - NRC FINAL SIGNIFICANCE DETERMINATION AND CLOSURE OF UNRESOLVED ITEM - REPORT 05000413/2007012 AND 05000414/2006012 Distribution:

J. Stang, NRR C. Evans, RII EICS L. Slack, RII EICS RIDSNRRDIRS OE Mail PUBLIC