ML18153B257
| ML18153B257 | |
| Person / Time | |
|---|---|
| Site: | Surry, Zion  |
| Issue date: | 12/14/1994 |
| From: | Hodges M NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Henry R FAUSKE & ASSOCIATES, INC. |
| References | |
| RTR-NUREG-CR-6109 NUDOCS 9503230101 | |
| Download: ML18153B257 (1) | |
Text
Dr. Robert E. Henry~
Fauske & Associates,..,,c.
- 16W070 West 83rd Street Burr Ridge, IL 60521
Dear Dr. Henry:
December 14, 1994 **
I have enclosed for your review a revised draft of NUREG-CR-6109, "The Probability of Containment Failure by Direct Containment Heating in Surry."
In its original draft form NUREG/CR-6109 was entitled, "Integrated Report on DCH Issue Resolution for PWRs" and as such the report addressed both the Zion and Surry plants as well as extrapolation to other PWR reactors.
In this revised draft, discussion of direct containment heating (DCH) issue resolution is confined to the Surry plant only, in much the same way as NUREG/CR-6075 and its supplement addressed DCH issue resolution for the Zion plant.
Extrapolation of DCH issue resolution findings to other reactors will be addressed in future documents.
In the preparation of this revised draft of NUREG/CR-6109 we have intended to address the nature of the peer review comments received during the review of NUREG/CR-6075, "The Probability of Containment Failure by Direct Containment Heating in Zion." Thus this report follows the methodology and scenarios described in the Zion reports, with obvious adjustments for the Surry design.
In that regard the evaluation of DCH loads was based on an assessment for new splinter scenarios shown to be consistent with the insights from SCDAP/RELAP5 analysis.
The notable area of difference between this report on Surry and the reports on Zion is that the Surry report describes that work done to evaluate the probability of unintentional depressurization (e.g., hot leg failure) due to circulation of hot gases/vapors in the reactor system.
This work is included to demonstrate how, in the broad evaluation of DCH, the probability of reactor vessel failure at low pressure may be factored to reduce the probability of containment failure.
While the probability of unintentional depressurization was not needed to show acceptable results for Surry (based on a loads evaluation there was no intersection of the loads and fragility curves) the discussion is provided as an indication of how such an integrated treatment of depressurization and loads evaluation would be undertaken.
We would like to receive your written comments by January 15, 1995.
The material in Appendices D and E will be forwarded as soon as it becomes available.
Please note that all comments received, along with the authors response, will be included in an Appendix to the final report. Should you have any questions regarding this request, please direct them to Dr. Richard Lee {301) 415-6795 of my staff.
Sincerely'/sl
( ------9503230l01--94121'f:*
M. Wayne ~ocfges, Director PDR ADOCK 05000280
/
Di vision of Systems Research E
PDR __
Office of Nuclear Regulatory Research
Enclosure:
As stated Identical Letters.sent to: Dr. Joseph E. Shepherd, Dr. Fred J. Moody, Dr. Mohammed Modarres, Dr. Mohammed Modarres, Dr. Salomon Levy, Professor M. Ishii Distribution DSR Chron, ~
Tinkler r/f, Tinkler, King, Hodges CF N
PDR N
Name: NUREG-CR.REV Disk: Tinkler 3 Office:
Name:
Date:
Official Record Copy 2~~0069 (rt1tZS~1
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