ML20141N081

Forwards Draft Repts Re Technical Insights Gained from Pras. Repts Include General Insights on Strengths & Weaknesses Gained from PRAs & Mods Implemented to Address Problems Identified During Pra.Comments Requested by 860325.W/o Encl

ML20141N081
Person / Time
Site:	LaSalle
Issue date:	02/24/1986
From:	Bournia A Office of Nuclear Reactor Regulation
To:	Farrar D COMMONWEALTH EDISON CO.
References
NUDOCS 8603030534
Download: ML20141N081 (2)

Text

. - . .

February 24, 1986 Docket Nos: 50-373 DISTRIBUTION:

and 50-374 .Doclet Nos. 50-373/374 NRC PDR Local PDR Mr. Dennis L. Farrar BWD-3 r/f Director of Licensing EAdensam-Commonwealth Edison Company EHyl ton P.O. Box 767 ABournia Chicago, Illinois 60690 RBernero -

Attorney, OELD. ,

Dear Mr. Farrar:

EJordan BGrimes

Subject:

Reports on PRA Insights j JPartlow ACRS (10)

-Enclosed are two draft reports concerning technical insights gained from i Probabilistic Risk Assessments (PRAs). These reports are the outcome of an on-going effort to make available and utilize in numerous technical and managerial

, activities the infomation 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 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; modifi-cations, both hardware and procedural, which have been implemented to address problems identified in the conduct or as a result of PRAs; insights into PRA i methodologies; and the contribution to measures of risk (core melt frequency l and consequences of radioactive releases) from systems, components and events.

1

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

i 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 i '

reports, you wish to provide comments to the staff, please provide them by

. March 25, 1986.

Sincerely, i

/S/

] Anthony Bournia, Project Manager BWR Project Directorate No.-3 Division of BWR Licensing _

Enclosures:

As stated 8603030534 e60224

, PDR ADOCK 05000373 P PDR cc: See next page g .

I BWD-3: DBL B  : DBL ABournia/hmc E e sam

-2/9 /86 2g(/86 7

4 y , c-, ,

e Mr. Dennis L. Farrar la Salle County Nuclear Power Station Commonwealth Edison Company IJnits 1 & 2 cc:

Philip P. Steptoe. Esquire John W. McCaffrey Suite 4200 Chief, Feblic Utilities D! vision One First Natioral Plaza 160 North La Salle Street, Room 900 Chicago, Illinois 60603 Chicago, Illinois 60601 Assistant Attorney General 188 West Randolph Street Suite 2315 Chicago, Illinois 60601 Resident Inspector /LaSalle, NPS U.S. Nuclear Regulatory Commission Rural Route No. 1 Post 0Ffice Box 224 Marseilles, Illinois 61341 Chairman La Salle County Board of Supervisors La Salle County Courthouse Ottawa, Illinois 61350 Attorney Aeneral 500 South 2nd Street Springfield, Illinois 62701 Chairman Illinois Commerce Commission Leland Building 527 East Capitol Avenue Springfield, Illinois 62706 Mr. Gary N. Wright, Manager Nuclear Facility Safety Illinois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 Regicnal Administrator, Region III U. S. Nuclear Regulatory Commission 799 Rossevelt Road Glen Ellyn, Illinois 60137 l

!