ML19291A087
| ML19291A087 | |
| Person / Time | |
|---|---|
| Site: | Midland, 05000595 |
| Issue date: | 06/10/1977 |
| From: | Ross D Office of Nuclear Reactor Regulation |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML111090060 | List:
|
| References | |
| FOIA-80-515, FOIA-80-555 NUDOCS 7904070090 | |
| Download: ML19291A087 (2) | |
Text
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UNITED STATES ch NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D. C. 20555 c wJ.i jun io 1977 Docket No.00-595 MEMORANDUM FOR:
D. B. Vassallo, Assistant Director for LWRs, DPM D. F. Ross, Jr., Assistant Director for Reactor Safety, DSS FROM:
SUBJECT:
SECOND ROUND COMMENTS - SWESSAR-P1 Plant Name:
SWESSAR-P1 Docket Number:
000595 Licensing Stage:
CP Responsible Branch LWR-1 and Project Manager:
H. Elliott Chakoff Systems Safety Branch Involved: Reactor Systems Branch Description of Review:
Second Round Comments Requested Completion Date:
July 1, 1977 Review Status:
Continuing The enclosed comment specifies requirements for systems to detect and isolate passive failures during long-term cooling following a LOCA.
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dY Denwood c. Ross, Jr., Assista.
irector for Reactor Safety Division of Systems Safety-
Enclosure:
Branch Position cc:
S. Hanauer T. Novak R. Heineman G. Mazetis J. Stol:
S. Israel S. Varga F. Orr K. Kniel RSB Members
- 0. Parr D. Ross H.E. Chakoff
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Contact:
Frank Orr, NRR 49-27591 g
7904070 0 9(;
Leak Detection Requirements for ECCS Passive Failures Reactor Systems Branch reviews postulated passive failures during long-term cooling following a postulated LOCA.
The passive failures considered are limited to leaks resultant from failures to valve stem packing and These leak rates range up to the equivalent of the sudden
-pump seals.
failure of the seal of the largest ECCS pump (about 50 gpm).
is the Reactor Systems Branch position that detection and alarms be It provided to alert the operator to passive ECCS failures during long-term cooling which allow suf ficient time to identify and isolate the f aulted The leak detection system should meet the following ECCS line.
requirements:
Identification and justification of maximum leak rate should be (1)
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provided.
Maximum allowable time for operatar action should be provided and (2) justified.
Demonstration should be provided that the leak detection system will (3) be sensitive enough to initiate (by alarm) operator action, permit identification of the faulted line, and isolation of the line prior to the leak creating undesirable consequences such as flooding of The minimum time to be considered is 30 minutes.
redundant equipment.
"'(4)
It should be shown that the leak detection system can identify the faulted ECCS train and that the leak is isolable.
(5) The leak detection system must meet the following standards:
(a) Control Room Alarm-(b) IEEE-279, except single failure requirements