ML20141K282

Forwards Draft Repts Re Technical Insights Gained from Four PRAs for Review.Comments Should Be Provided by 860210. Discussion Includes General Insights on Plant Strengths & Weaknesses.W/O Encls

ML20141K282
Person / Time
Site:	Fort Saint Vrain
Issue date:	01/14/1986
From:	Berkow H Office of Nuclear Reactor Regulation
To:	Walker R PUBLIC SERVICE CO. OF COLORADO
References
NUDOCS 8601220429
Download: ML20141K282 (4)

Text

I / 'o UNITED STATES

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8 o NUCLEAR REGULATORY COMMISSION y a E WASHINGTON, D. C. 20655

% , , , , , +# January 14, 1986 i

Docket No. 50-267 Mr. R. F. Walker, President Public Service Company of Colorado Post Office Box 840 Denver, Colorado 80201

SUBJECT:

REPORTS ON PRA INSIGHTS Enclosed are two draft reports concerning the technical insights that have been gained from four 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 and/or operational practices which have been found to be important to safety in the plants which have been subjected to the risk assess:aents. In addition, the section on insights into PRA methodologies focuses on areas which are seccitive 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; modifications, 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.

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I Mr. R. F. Walker 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 nuclear power plant licensees, in advance of formal publication for your information. If, after reviewing these reports, you wish to prdvide comments to the staff, please provide them by February 10, 1986. -

Sincerely, l j -

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/ Herbert N. Berkow, Director .

Standardization and Special Projects Directorate .

Division of PWR Licensing-B

Enclosures:

As stated cc w/ enclosure:

See next page

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6 Mr. R. F. Walker Public Service Company of Colorado Fort St. Vrain cc:

C. K. Millen Albert J. Hazle, Director Senior Vice President Radiation Control Division Public Service Company 4210 East lith Avenue of Colorado Denver, Colorado 80220 P. O. Box 840 Denver, Colorado 80201 J. W. Gahm Nuclear Production Manager Mr. David Alberstein, 14/159A Public Service Company of Colorado GA Technologies, Inc. P. O. Box 368 P. O. Box 840 Platteville, Colorado 80651 Denver, Colorado 80201 J. K. Fuller, Vice President Public Service Company of Colorado P. O. Box 840 Denver, Colorado 80201 Senior Resident Inspector U.S. Nuclear Regulatory Commission P. 0. Box 640 Platteville, Colorado 80651 Kelley, Stansfield & 0'Donnell

, Public Service Company Building Room 900 550 15th Street Denver, Colorado 80202 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Office of Executive Director for Operations 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Chairman, Board of County Commissioners '

of Weld County, Colorado Greeley, Colorado 80631 Regional Representative Radiation Programs Environmental Protection Agency 1800 Lincoln Street Denver, Colorado 80651 jk

. January 14, 1986 Mr. R. F. Walker These reports will be published in their final forms in approximately two months. These reports are tseing provided to you, as well as all other nuclear power plant licensees, in advance of formal publication for your information. If, after reviewing these reports, you wish to provide coments to the staff, please provide them by February 10, 1986.

Sincerely.

Original signed by Herbert N. Berkow, Director Standardization and Special Projects Directorate Division of PWR Licensing-B

Enclosures:

As stated cc w/ enclosure:

See next page DISTRIBUTION:

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