ML20141K337

Forwards Draft Repts Re Technical Insights Gained from PRAs for Review by 860210.Repts Discuss General Insights on Plant Strengths & Weaknesses & Contribution to Core Melt Frequency from Sequences Induced by Initiating Events.W/O Encls

ML20141K337
Person / Time
Site:	Maine Yankee
Issue date:	01/09/1986
From:	Thadani A Office of Nuclear Reactor Regulation
To:	Randazza J Maine Yankee
References
NUDOCS 8601220455
Download: ML20141K337 (2)

Text

January 90 1986

~

Docket No. 50-309 NRC & Local PDR ACRS (10) FMiraglia MY File JPartlow PKreutzer BGrimes PSears AThadani PWR8 Reading Edordan

• Dockst" File %

Mr. J. B. Randazza i

Executive Vice President Maine Yankee Atomic Power Company 4 83 Edison Drive

Augusta, Maine 04336

SUBJECT:

REPORTS ON PRA INSIGHTS Enclosed are two draft raports concerning technical insights gained from Probabilistic Risk Assessments (PRAs). These reports are the outcome of an ongoing effort to make available and utilize in numerous technical and managerial activities the information in probabilistic risk assessments regarding the factors which dominate the risk associated with nuclear power plants. This effort includes identification of the features of design or operational practices which have been found to be important to safety in the types of plants which have been subjected to risk assessments. In addition, the section on insights into PRA methodologies focuses on areas which are sensitive to the results and the overall perception of plant weaknesses and vulnerabilities.

In particular, these reports contain discussions of: general insights on plant strengths and weaknesses gained from PRAs; the contribution to core melt frequency

from classes of sequences induced by various initiating events; rodifications, l both hardware and procedural, which have been implemented to address problems identified in the conduct or as a result of PRAs; insights into PRA methodologies; and the contribution to measures of risk (core melt frequency and consequences of radioactive releases) from systems, components and events.

These reports will be published in their final forms in approximately two months.

These reports are being provided to you, as well as all other licensees, in advance of formal publication for your information. If, after reviewing these reports, you wish to provide comments to the staff, please provide them by February 10, 1986.

Sincerely,

/S/

j Ashok Thadani, Director PWR Project Directorate #8 Division of PWR Licensing - B

Enclosures:

As Stated

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. I j o Mr. J. B. Randazza Maine Yankee Atomic Power Company Maine Yankee Atomic Power Station l

i cc:

i Charles E. Monty, President Mr. P. L. Anderson, Pro.iect Manager j Maine Yankee Atomic Power Company Yankee Atomic Electric Company

! 83 Edison Drive 1671 Worchester Road i Augusta, Maine 04336 Framingham, Massachusetts 07101 I

! Mr. Charles B. Brinkman Mr. G. D. Whittier j Manager - Washington Nuclear Licensing Section Head Operations Maine Yankee Atomic Power Company

{ Combustion Engineering, Inc. 83 Edison Drive 7910 Woodmont Avenue Augusta, Maine 04336

) Bethesda, Maryland 20814 John A. Ritsher, Esquire Ropes & Gray 225 Franklin Street Boston, Massachusetts 02110 i

State Planning Officer Executive Department

! 189 State Street l Augusta Maine 04330 1

l Mr. John H. Garrity, Plant Manager j Maine Yankee Atomic Power Company i P. O. Rox 408 l t-Wiscasset, Maine 04578 i

, Regional Administrator, Region I

! U.S. Nuclear Regulatory Connission ,

l 631 Park Avenue '

King of Prussia, Pennsylvania 19406 l First Selectman of Wiscasset j Municipal Building

U.S. Route I Wiscasset, Maine 04578

! Mr. Cornelius F. Holden j Resident inspector c/o ll.S. Nuclear Regulatory Commission ,

P. O. Box E Wiscasset, Maine 04578 1

I I

)

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