ML20128L293

Forwards SER Re GL 88-20, Individual Plant Exam for Severe Accident Vulnerabilities, & Technical Evaluation Rept

ML20128L293
Person / Time
Site:	Davis Besse
Issue date:	10/02/1996
From:	Gundrum L NRC (Affiliation Not Assigned)
To:	Jeffery Wood CENTERIOR ENERGY, TOLEDO EDISON CO.
Shared Package
ML20128L299	List: ML20128L293 ML20128L300 ML20129D821
References
GL-88-20, TAC-M74402, NUDOCS 9610150002
Download: ML20128L293 (3)

Text

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49 -SLQ ge yg 4 UNITED STATES s** ,j

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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2066H001

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October 2, 1996 Mr. John K. Wood Vice President - Nuclear, Davis-Besse  ;

Centerior Service Company c/o Toledo Edison Company i i

Davis-Besse Nuclear Power Station i 5501 North State Route 2 )

Oak Harbor, OH 43449-9760

SUBJECT:

STAFF EVALUATION REPORT FOR GENERIC LETTER 88-20, " INDIVIDUAL PLANT EXAMINATION - DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 (TAC NO. M74402) i

Dear Mr. Wood:

Enclosed is the NRC Staff Evaluation Report (SER) for the Davis-Besse Nuclear Power Station (DBNPS) Individual Plant Evaluation (IPE) based on your submittals of February 26, 1993, as supplemented on September 11, 1995. Your 1

submittals were in response to Generic Letter (GL) 88-20, " Individual Plant Examination For Severe Accident Vulnerabilities." ,

i A " Step 1" review was performed which examined the IPE results for their l

" reasonableness" considering the design and operation of DBNPS. The staff employed Brookhaven National Laboratory (BNL) to review the IPE submittal.

The enclosed BNL Technical Evaluation Report was evaluated by the IPE " Senior Review Board" as part of the quality assurance process. The Senior Review Board is comprised of NRC staff and a consultant from Sandia National Laboratory with probabilistic risk assessment expertise.

The IPE estimated a total core damage frequency (CDF) of 6.6E-5 per reactor year, including a contribution from internal flooding of 2.0E-6 per reactor year. Of this total frequency, transients contribute 86 percent (including a 2 percent contribution from station blackout), loss-of-coolant accidents (LOCAs) 8.6 percent, internal flooding 3 percent, interfacing system LOCAs 1.3 percent, and steam generator tube rupture 0.7 percent.

You defined a vulnerability as either (1) a CDF significantly higher than 1.0E-4 per reactor year with one or a few aspects of the plant design or operating practices contributing to such a high frequency, (2) a single plant feature (or a few features) which causes a disproportionately high j contribution to the CDF, or (3) a CDF that is very sensitive to a hi.ghly uncertain aspect of plant response. Based on this definition, you did not identify any vulnerabilities. Plant improvements, however, were identified and have either been implemented or are under evaluation.

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100093 NRC FILE CEM M -

9610150002 961002 PDR ADOCK 05000346 p PDR

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_2- j Based on this " Step 1" review, the NRC staff concluded that you have met the intent of.GL 88-20 and as:9ciated guidance in NUREG-1335, " Individual Plant Examination: Submittal Guidaime."

Sincerely,.

M.58Hd W Linda L. Gundrum, Project Manager Project Directorate III-3 Division of Reactor Projects III/IV -

1 Office of Nuclear Reactor Regulation i Docket No. 50-346

Enclosures:

1. Safety Evaluation

2. Appendix - Technical Evaluation Report cc w/encls: See next page r

Distribution w/encls:  !

IDocket File:-e PUBLIC PD3-3 Reading >

ACRS ,

OGC Distibution w/o Enc 1 2 PD3-3 Reading j JRoe EAdensam (E)

GMarcus RHernan JCaldwell, RIII JLane, RES DOCUMENT NAME: G:\DAVISBES\DB74402.SER

• SE input dated 9/23/96 was provided and no major changes were made.

To receive e copy of this document, Indicate in the box: "C" = copy without enclosures *E" = Copy with enclosures "N" = No copy 0FFICE PD33-LA l El PD33-PM lE RES/ DST l l l NAME DFoster-Curseen LGundrum >QYd,

• DATE 10/A/96 D . ht)/; /96 _ 9/23/96

1. OFFICIAL RECORD COPY

Mr. John K. Wood Davis-Besse Nuclear Power Station Toledo Edison Company Unit No. I cc:

Mary E. O'Reilly Robert E. Owen, Chief Centerior Energy Corporation Bureau of Radiological Health 300 Madison Avenue Service Toledo, Ohio 43652 Ohio Department of Health P. O. Box 118 Mr. James L. Freels Columbus, Ohio 43266-0118 Manager - Regulatory Affairs i Toledo Edison Company Davis-Besse Nuclear Power Station Attorney General ,

5501 North State - Route 2 Department of Attorney Oak Harbor, Ohio 43449-9760 30 East Broad Street Columbus, Ohio 43216 Gerald Charnoff, Esq.

Shaw, Pittman, Potts Mr. James W. Harris, Director and Trowbridge Division of Power Generation 2300 N Street, M.P. Ohio Department of Industrial I Washington, D.C. 20037 Regulations P. O. Box 825 Regional Administrator Columbus, Ohio 43216 U.S. NRC, Region III 801 Warrenville Road Ohio Environmental Protection Agency Lisle, Illinois 60523-4351 DERR--Compliance Unit ATTN: Zack A. Clayton Mr. Robert B. Borsum P. O. Box 1049 Babcock & Wilcox Columbus, Ohio 43266-0149 Nuclear Power Generation Division 1700 Rockville Pike, Suite 525 State of Ohio Rockville, Maryland 20852 Public Utilities Commission 180 East Broad Street Resident Inspector Columbus, Ohio 43266-0573 U. S. Nuclear Regulatory Commission j 5503 N. State Route 2 Mr. James R. Williams .

Oak Harbor, Ohio 43449 Chief of Staff l Ohio Emergency Management Agency l Mr. James H. Lash, Plant Manager 2855 West Dublin Granville Road Toledo Edison Company Columbus, Ohio 43235-2206 Davis-Besse Nuclear Power Station 5501 North State Route 2 President, Board of County Oak Harbor, Ohio 43449-9760 Commissioner of Ottawa County Port Clinton, Ohio 43452 1

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