ML063200384

Final Accident Sequence Precursor Analysis of April 2003 Operational Event, LER 416/03-002 - Letter to Licensee W/Copy of Final ASP Analysis

ML063200384
Person / Time
Site:	Grand Gulf
Issue date:	12/05/2006
From:	Bhalchandra Vaidya NRC/NRR/ADRO/DORL/LPLIV
To:	Brian W Entergy Operations
Vaidya B, NRR/DORL/LP4, 415-3308
Shared Package
ML063210035	List: ML063200384
References
Download: ML063200384 (4)

Text

December 5, 2006 Mr. William R. Brian Vice President of Operations Grand Gulf Nuclear Station Entergy Operations, Inc.

P.O. Box 756 Port Gibson, MS 39150

SUBJECT:

GRAND GULF NUCLEAR STATION, UNIT 1 - RE: FINAL ACCIDENT SEQUENCE PRECURSOR ANALYSIS OF APRIL 2003 OPERATIONAL EVENT, LER 416/03-002

Dear Mr. Brian:

Enclosed are the final results of the Accident Sequence Precursor (ASP) analyses of an event which occurred at Grand Gulf Nuclear Station, Unit 1 (GGNS), as documented in Licensee Event Report (LER) 416/03-002. The subject event occurred on April 14, 2003, during which GGNS experienced an automatic reactor scram due to loss of offsite power with the condenser vacuum pump inoperable and subsequent failure of instrument air, and was reported in LER 416/03-002. The ASP analysis (Agencywide Documents Access and Management System (ADAMS) Accession No. ML062710045) calculated a mean conditional core damage probability of 1.3 x 10-6. The final ASP analyses were previously sent to the licensee and the Office of Nuclear Reactor Regulation (NRR) staff for review. NRR and licensee comments have been addressed in the enclosed analyses.

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.

• 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).

W. Brian 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.

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

If you have any questions, please contact me at 301-415-3308.

Sincerely,

/RA/

Bhalchandra Vaidya, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-416

Enclosure:

Final ASP Analysis cc w/encl: See next page

Pkg ML063210035 (Letter ML063200384, Enclosure ML062710045)

OFFICE NRR/LPLIV/PM NRR/LPLIV/LA RES/DRASP/D NRR/LPLIV/BC NAME BVaidya LFeizollahi FEltawila DTerao DATE 11/28/06 11/27/06 11/1/06 11/30/06 Grand Gulf Nuclear Station cc:

Executive Vice President Office of the Governor

& Chief Operating Officer State of Mississippi Entergy Operations, Inc. Jackson, MS 39201 P.O. Box 31995 Jackson, MS 39286-1995 Attorney General Asst. Attorney General Chief State of Mississippi Energy and Transportation Branch P.O. Box 22947 Environmental Compliance and Jackson, MS 39225-2947 Enforcement Division Mississippi Department of Environmental Vice President, Operations Support Quality Entergy Operations, Inc.

P.O. Box 10385 P.O. Box 31995 Jackson, MS 39289-0385 Jackson, MS 39286-1995 President Director Claiborne County Nuclear Safety Assurance Board of Supervisors Entergy Operations, Inc.

P.O. Box 339 P.O. Box 756 Port Gibson, MS 39150 Port Gibson, MS 39150 Regional Administrator, Region IV Director U.S. Nuclear Regulatory Commission Nuclear Safety & Licensing 611 Ryan Plaza Drive, Suite 400 Entergy Operations, Inc.

Arlington, TX 76011-8064 1340 Echelon Parkway Jackson, MS 39213-8298 Senior Resident Inspector U.S. Nuclear Regulatory Commission Manager, Licensing P.O. Box 399 Entergy Operations, Inc.

Port Gibson, MS 39150 P.O. Box 756 Port Gibson, MS 39150 General Plant Manager Operations Richard Penrod, Senior Environmental Entergy Operations, Inc. Scientist/State Liaison Officer P.O. Box 756 Office of Environmental Services Port Gibson, MS 39150 Northwestern State University Russsell Hall, Room 201 Attorney General Natchitoches, LA 71497 Department of Justice State of Louisiana P.O. Box 94005 Baton Rouge, LA 70804-9005 State Health Officer State Board of Health P.O. Box 139 Jackson, MS 39205 November 2006