NUREG/CR-4405, Forwards Advance Copies of Draft NUREG/CR-4405, PRA Insights & Reliability & Risk Assessment Branch Draft Rept, Insights Gained from Pras, for Comments & Suggestions
| ML20210K637 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Oconee, Seabrook, Comanche Peak, 05000000, Shoreham |
| Issue date: | 04/21/1986 |
| From: | Noonan V Office of Nuclear Reactor Regulation |
| To: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| Shared Package | |
| ML20210K640 | List: |
| References | |
| RTR-NUREG-CR-4405 NUDOCS 8604280409 | |
| Download: ML20210K637 (1) | |
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Docket Nos.
50-445 and 50-446 Mr. W. G. Counsil Executive Vice President Texas Uitilties Generating Company 400 North Olive Street, L B. 81 Dallas, Texas 75201
Dear Mr. Counsil:
SUBJECT:
REPORTS ON PRA INSIGHTS - Comanche Peak 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 PRAs 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; 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.
These reports are being provided to you, as well as all other licensees, in advar.ce of formal publication for your information. Your comments and suggestions are welcome on these reports.
Sincerely, Vincent S. Noonan, Director PWR Project Directorate # 5 Division of PWR I.icensing-A Dis ibution:
Enclosures:
As stated NRC PDR.
A. Vietti-Cook P
DIR:PD#5 Local PDR M. Rushbrook PD#5 R/F ACRS (10) 4/6/86 T. Novak OELD J. Partlow 8604200409 860421 B. Grimes PDR ADOCK 0500 5
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