ML070520450

Regarding Accident Sequence Precursor Analysis of the May 20, 2006 Operational Event, LER 413/06-001

ML070520450
Person / Time
Site:	Catawba
Issue date:	02/27/2007
From:	Stang J NRC/NRR/ADRO/DORL/LPLII-1
To:	Morris J Duke Power Co
Stang J, NRR/DORL, 415-1345
References
LER 413/06-001
Download: ML070520450 (5)

Text

February 27, 2007 Mr. J. R. Morris Site Vice President Catawba Nuclear Station Duke Power Company LLC 4800 Concord Road York, SC 29745

SUBJECT:

CATAWBA NUCLEAR STATION, UNITS 1 AND 2 - FINAL ACCIDENT SEQUENCE PRECURSOR ANALYSIS OF THE MAY 20, 2006, OPERATIONAL EVENT, LER 413/06-001

Dear Mr. Morris:

Enclosed are the final results of the Accident Sequence Precursor (ASP) analyses of an event which occurred at Catawba Nuclear Station, Units 1 and 2 (CNS), as documented in Licensee Event Report (LER) 413/06-001. The subject event occurred on May 20, 2006, during which CNS Units 1 and 2 experienced an automatic reactor scram due to loss of all offsite power (LOOP) and was reported in LER 413/06-001. The ASP analysis available in the Agencywide Documents Access and Management System (ADAMS), Accession No. ML062710061, calculated a mean conditional core damage probability (CCDP) of 9 x 10-5 for Unit 1 and a mean CCDP of 6 x 10-5 for Unit 2.

The Nuclear Regulatory Commission (NRC) established the ASP Program in 1979 in response to the Risk Assessment Review Group report (see NUREG/CR-0400, dated September 1978).

The ASP Program systematically evaluates U.S. nuclear power plant operating experience to identify, document, and rank the operating events that were most likely to have led to inadequate core cooling and severe core damage precursors, accounting for the likelihood of additional failures.

The ASP Program has the following objectives:

• Provide a measure for trending nuclear power plant core damage risk.

• Provide a partial check on dominant core damage scenarios predicted by probabilistic risk assessments (PRAs).

• Provide feedback to regulatory activities.

• Evaluate the adequacy of NRC programs.

The NRC also uses the ASP Program to monitor performance against the safety goal established in the agency's Strategic Plan (See NUREG-1100, Vol. 21, dated February 2005).

For more information about the ASP Program, see the annual ASP Program Report at http://www.nrc.gov/reading-rm/doc-collections/commission/secys/2005/secy2005-0192/2005-01 92scy.pdf.

J. Morris The enclosure is provided for your information and no response is requested.

If you have any questions regarding this correspondence, please contact me at 301-415-1345.

Sincerely,

/RA/

John Stang, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-413 and 50-414

Enclosure:

Final ASP Analysis cc w/encl: See next page

J. Morris February 27, 2007 The enclosure is provided for your information and no response is requested.

If you have any questions regarding this correspondence, please contact me at 301-415-1345.

Sincerely,

/RA/

John Stang, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-413 and 50-414

Enclosure:

Final ASP Analysis cc w/encl: See next page DISTRIBUTION:

PUBLIC RidsResDrasp (FEltawila)

LPL2-1 R/F RidsAcrsAcnwMailCenter RidsRgn2MailCenter(JMoorman) JRobinson, PGCB RidsNrrDorlLpl2-1 (EMarinos) GDemoss, DRASP/OERA RidsNrrDorl (CHaney/JLubinski) RidsOgcRp RidsNrrPMJStang (hard copy) EGoldfeiz, DRASP/OERA RidsNrrLAMOBrien (hard copy)

Accession No.: ML070520450 OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA RES/DRASP/D NRR/LPL2-1/BC NAME JStang:nc MOBrien FEltawila EMarinos DATE 2/26/07 2/26/07 02/06/07 2/27/07 OFFICIAL RECORD COPY

Catawba Nuclear Station, Units 1 & 2 Page 1 of 2 cc:

Mr. Dhiaa Jamil Senior Resident Inspector Vice President U.S. Nuclear Regulatory Commission Catawba Nuclear Station 4830 Concord Road Duke Power Company, LLC York, South Carolina 29745 4800 Concord Road York, SC 29745 Mr. Henry Porter, Assistant Director Division of Waste Management Mr. Lee Keller, Manager Bureau of Land and Waste Management Regulatory Compliance Dept. of Health and Environmental Control Duke Energy Corporation 2600 Bull Street 4800 Concord Road Columbia, South Carolina 29201-1708 York, South Carolina 29745 Mr. R.L. Gill, Jr., Manager Ms. Lisa F. Vaughn Nuclear Regulatory Issues Associate General Counsel and Managing and Industry Affairs Attorney Duke Energy Corporation Duke Energy Carolinas, LLC 526 South Church Street 526 South Church Street - EC07H Mail Stop EC05P Charlotte, North Carolina 28202 Charlotte, North Carolina 28202 North Carolina Municipal Power Saluda River Electric Agency Number 1 P.O. Box 929 1427 Meadowwood Boulevard Laurens, South Carolina 29360 P.O. Box 29513 Raleigh, North Carolina 27626 Mr. Peter R. Harden, IV, Vice President Customer Relations and Sales County Manager of York County Westinghouse Electric Company York County Courthouse 6000 Fairview Road York, South Carolina 29745 12th Floor Charlotte, North Carolina 28210 Piedmont Municipal Power Agency 121 Village Drive Mr. T. Richard Puryear Greer, South Carolina 29651 Owners Group (NCEMC)

Duke Energy Corporation Mr. Leonard G. Green 4800 Concord Road Assistant Attorney General York, South Carolina 29745 North Carolina Department of Justice P.O. Box 629 Ms. Kathryn B. Nolan Raleigh, North Carolina 27602 Senior Counsel Duke Energy Carolinas, LLC NCEM REP Program Manager 526 South Church Street - EC07H 4713 Mail Service Center Charlotte, NC 28202 Raleigh, North Carolina 27699-4713 North Carolina Electric Membership Corp.

P.O. Box 27306 Raleigh, North Carolina 27611

Catawba Nuclear Station, Units 1 & 2 Page 2 of 2 cc:

Division of Radiation Protection NC Dept. of Environment, Health, and Natural Resources 3825 Barrett Drive Raleigh, North Carolina 27609-7721 Mr. Henry Barron Group Vice President, Nuclear Generation and Chief Nuclear Officer P.O. Box 1006-EC07H Charlotte, NC 28201-1006