ML20137L265

Forwards for Comments by 860224,two Draft Repts Re Pras. Insights Re Plant Strengths & Weaknesses,Core Melt Frequency,Procedural & Hardware Mods & PRA Methodologies Discussed.Repts Will Be Published in 2 Months.W/O Encls

ML20137L265
Person / Time
Site:	Perry
Issue date:	01/22/1986
From:	Stefano J Office of Nuclear Reactor Regulation
To:	Edelman M CLEVELAND ELECTRIC ILLUMINATING CO.
References
NUDOCS 8601270375
Download: ML20137L265 (3)

Text

. .

JAN 2 2 in Docket Hos. 50-440/441 DISTRIBUTION L Docket File JStefano NRC PDR MRushbrook Mr. Murray R. Edelman Local PDR ACRS (10)

Vice President - Nuclear Operations PD#4 Reading The Cleveland Electric RBernero Illuminating Company Woodhead, OELD Post Office Box 5000 EJcrdan Cleveland, Ohio 44101 BGrimes JPartlow

SUBJECT:

REPORTS ON PRA INSIGHTS Enclosed are two draft reports concerning technical insights gained frcm Probabilistic Risk Assessments (PRAs). These reports are the outcome of an ongoing effort to nake 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 a'.sessments. In additicn, the section on insights into PRA method focuses on areas which are sensitive to the results and the overall perception of plant weaknesses and vulnera-bilities.

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; irodifications, 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 approxinately two months. These reports are being provided to you, as well as all other licensees, in advance of formal publication for your information. If, efter reviewing these reports, you wish to provide ccmments to the staff, please provide them by February 24, 1986.

Sincerely, orwna; nnca by John J. Stefano, Project Manager BWR Project Directorate No. 4 Division of BUR Licensing

Enclosures:

As stated f cc: See next page PD#4/PM Stefano:lb 1/')t/86 0

$$0# Och 0 a

., +f jog UNITED STATES 8 o NUCLEAR REGULATORY COMMISSION 5 p WASHINGTON, D. C. 20555

.....* JATJ 2 21336 Docket Nos. 50-440/441 Mr.11urray R. Edelman Vice President - Nuclear Operations The Cleveland Electric Illuminating Company Post Office Box 5000 Cleveland, Ohio 44101

SUBJECT:

REPORTS ON PRA INSIGHTS Enclosed are two draft reports 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 method focuses on areas which are sensitive to the results ano the overall perception of plant weaknesses and vulnera-bilities.

In particular, these reports contain discussions of: general insights on plant strengths and weaknesses gained f rom 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 prcblems 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 ycur infonr.ation. If, after reviewing these reports, >cu wish to provide comments to the staff, please provide them by February 24, 1986.

Sincerel , ,-

v.bte a roje t nager BW R Pro-ect Di ectora No. 4

[ D'visi<n of B < Lice s ng l

Enclosures:

As stated cc: See next page

\1

\

, Mr. Murray R. Edelman Perry Nuclear Power Plant The Cleveland Electric Units 1 and 2 Illuminating Company cc:

Jay Silberg, Esq. Mr. Larry 0. Beck Shaw, Pittman, & Trowbridge The Cleveland Electric 1800 M Street, H. W. Illuminating Company Washington, D. C. 20006 P. O. Box 97 E-210 Perry, Ohio 44081 Donald H. Hauser, Eso.

The Cleveland Electric Illuminating Company P. O. Box 5000 Cleveland, Ohio 44101 Resident Inspector's Office

~

U. S. Nuclear Regulatory Commission i Parmly at Center Road Perry, Ohio 44081 Regional Administrator, Region Ill U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Donald T. Ezzone, Esq. .

Assistant Prosecuting Attorney 105 hain Street Lake County Administration Center Painesville, Ohio 44077 Ms. Sue Hiatt OCRE Interin Representative 8275 Munson Mentor, Chio 44060 Terry J. Lodge, Esq.

618 N. Michigan Street Suite 105 Toledo, Ohio 43624 John G. Cardinal, Esq.

Prosecuting Attorney Ashtabula County Courthouse Jefferson, Ohio 44047

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