ML19345B939
| ML19345B939 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse, Rancho Seco, Crane |
| Issue date: | 02/07/1980 |
| From: | Abbott E, Bickel J, Kastenberg W Advisory Committee on Reactor Safeguards |
| To: | Okrent D Advisory Committee on Reactor Safeguards |
| Shared Package | |
| ML19345B940 | List: |
| References | |
| ACRS-R-0862A, ACRS-R-862A, NUDOCS 8012020797 | |
| Download: ML19345B939 (1) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION 8 ' 3,,
g ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON. D. C. 20555 r
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February 7, 1980 David Okrent, Chairman, Subcomittee on Reliability and Probabilistic Assessment ANALYSIS OF FEEDWATER TRANSIENT SEQUENCES IN B&W NUCLEAR STEAM SUPPLY SYSTE To aid in the Subcomittee's work in formulating a response to Congressman Udall's letter of July 29, 1979, please find attached a draft of our analysis of the t ree Mile Island, Rancho Seco, and Davis Besse events. Using the WASH-1400 event trees and data directly gives meaningless results because several important features of the sequences are omitted. Using an event tree which we constructed for B&W feedwater transients, and using WASH-1400 methodo-logy and data, we obtain the following:
-4 Rancho Seco 1.2 x 10 /B&W reactor year
-3 Davis Besse 1.2 x 10 /B&W reactor year
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-4 t ree Mile Island 1.5 x 10 /B&W reactor year A major uncertainty is the characterization of operator behavior. It appears that with appropriate use of WASH-1400 methodology and data, events of this type m uld be anticipated.
The study will be distributed to all Subcommittee Members and appropriate con-sultants.
If you have any questions, please do not hesitate to call us.
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Edward Abbott, ACRS Senior Fellow
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John Bickel, ACRS Fellow William Kastenber'g, ACRS Seni ellow f 6 /20% b77 7
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