ML19317E887
| ML19317E887 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/12/1973 |
| From: | Stello V US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001070687 | |
| Download: ML19317E887 (2) | |
Text
r NRR 12 gy3 R. C. DeYoung, Assistant Director for Pressurized Water Reactors, L RIEL DI2tSITICATIOft REVIEW OF OCONEE 1 In our ongoing fuel densification review of Oconee 1, we find that-the ground rules to be used in the safety analysis by MW needs more definition. ho particular items have arisen where there is dissgreement between EW and the staff as to what are appropriate ground rules in regard to vent valve malfunctions and when film boiling should be assumed to occur.
In this regard, we feel it necessary to state the ataff's position on these items to the affected applicant Duke Power Company, and request you forward the attached position.
t origtnni signed by Victor Stello Victor Stallo, Jr., Assistant Director for Reactor Safety Directorate of Licensing Distribution:
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To clarify the ground rules for the safety analyses to be conducted in the Regulatory staff's continuing review of the oconee operating license application, our position in regard to c
the appropriate con.scrvative assumptions for an assumed vent valve malfunction and the criteria for determining departure from nucicate boiling and subscouent degraded heat transfer is given below:
1.
Since the status of vent valves (open or closed) are not directly monitored and there is limited operating experience i
with these devices; one vent valve should be assumed to malfunction in either the closed or open position (whichever is more conservative) for safety analyses.
2.
Departure from nucleate boiling (DNB) and a subsequent degraded heat transfer condition should be assumed whenever a DNBR equal to or less than 1.3 is predicted. For this purpose the use of the TEMP code and the B&W-2 correlation is acceptable.
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