ML16341D782
| ML16341D782 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/16/1986 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Shiffer J PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8606240513 | |
| Download: ML16341D782 (6) | |
Text
June 16, 1986 Docket Nos.
50-275 and 50-323 J.
D. Shiffer, Vice President Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Francisco, California 94106
Dear Mr. Shiffer:
DISTRIBUTION w/o enclosure
- ~
NRC POR H. Thompson N. Thompson H. Schierling C. Vogan S.
Varga
- ACRS(10)-
S. Davis N. Chokshi L. Reiter G. Giese-Koch PAD-3 Rdg.
B. Grimes J. Partlow OELD PDR (Local PDR with enclosure)
SUBJECT:
NRC REPORTS ON PRA INSIGHTS - DIABLO CANYON Enclosed are two draft reports concerning technical insights gained from Probabilistic Risk Assessments (PRAs).
These reports are the outcome of an ongoing NRC effort to make available and utilize in numerous technical and managerial activities the information in PRA's 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 PRA's; 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 PRA's; 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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These reports are being provided to you, as well as other licensees, in advance of formal publication for your information.
Your comments and suggestions are welcome on these reports.
Sincerely, cc: w/o enclosre:
See next page
Enclosures:
Steven A. Varga, Director PWR Project Directorate No.
3 Division of PWR Licensing-A, NRR 1.
"Insights Gained from Probabilistic Risk Assessments" by S. Davis,
- USNRC, September 20, 1984.
2.
"Probabilistic Risk Assessment (PRA)
Insights",
NUREG/CR-4405; BNL/NUREG-51931, Brookhaven National Laboratory, December 1985.
PAD-3 C.
Vogan H. Schi ing;b S.
Va a
06/12/86 06/e86 06+
l c I
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1 3
l I
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These reports are being provided to you, as well as other licensees in advance of formal publication for your information.
Your comments and suggestions are welcome on these reports.
Sincerely, cc: w/o enclosre:
See next page
Enclosures:
Steven A. Varga, Director PWR Project Directorate Po.
3 Division of PWR Licensi6g-A, NRR' k
n
'\\
1.
Insight Gained from Probabilistic Risk Assessments" by S. Davis,
- USNRC, September 20, 1984.
2.
"Probabilistic Risk Assessment (PR
)
(PRA) Insight", NUREG/CR-4405; BN /NUREG-51931, Brook Laren National Laboratory, Department 1985.
PAD-3 5 PAD-3 PAD-3 C.
Vogan H.
Sc ierling;bs S.
Varga 06/0/86 06/
86 06/ /86
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