ML19309F339
| ML19309F339 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/24/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Rubenstein L Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8004290290 | |
| Download: ML19309F339 (7) | |
Text
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TI&
8004290 M o
. - 6 400 Chestnut Street Tower II April 24, 1980 Director of Nuclear Reactor Regulation Attention:
Mr. L.
S. Rubenstein, Acting Chief Light Water Reactors Branch No. 4 Division of Project Management U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Rubenstein:
In the Matter of the Application of
)
Docket Nos. 50-327 Tennessee Valley Authority
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50-328 The Sequoyah Nuclear Plant Engineered Safety Features (ESF) were reviewed in accodance with the six criteria transmitted by your letter to H. G. Parris dated March 19, 1980.
Enclosed are the results of this review.
TVA is in compliance with all of the criteria except f;r the one point outlined in item 1.
Design changes have been initiated to bring Sequoyah Nuclear Plant into full compliance.
If you have any questions, please get in touch with D. L. Lambert at FTS 854-2581.
Very truly yours, TENNESSEE VALLEY AUTh0RITY A
l
- d. /D< b$
. M. Mills,' Manager Nuclear Regulation and Safety Enclosure gou se
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(1)
It is the NRC's position that the overriding of one type of safety actuation signal (e.g., particulate radiation) should not cause the blocking of any other type of safety actuation signal (e.g.,
iodine radiation, reactor pressure) for those valves that have no function other than containment isolation.
Response
The containment high radiation and containment isolation (safety injection signal) are treated as one signal.
If one of the signals is present and has been overridden bv the manual reset switch, the other signal will be blocked as long as the overridden signal is present. This is part of the Westinghouse solid state protection system design. These signals control the containment purge valves.
i (2)
It is the NRC's position that physical features (e.g., key lock switches) should be provided to ensure adequate administrative controls.
Resconse Physical features are used, where required, to ensure adequate aduini-strative controls.
l (3)
It is the NRC's position that a system level annunciation of the overridden status should be provided for every safety system impacted when any override is active.
(See Regulatory Guide 1.47).
Response
Bypass signals are annunciated. Manual override of signals is not annunciated but is indicated on status lights.
This meets the require:aents of Regulatory Guide 1.47, " Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems."
(4)
It is the NRC's position that the following diverse signals should be provided to initiate isolation of the containment purge /ventila-tion system; containment high radiation, safety injection actuation, and containment high pressure (where containment high pressure is not a portion of safety injection actuation).
Response
Iso.'.ation of containment purge valves is initiated by containment radiation and safety injection where containment high pressure is a portion of S.I.
actuation.
(5)
It is the NRC's position that the instrumentation systems provided to initiate containment purge ventilation isolation should be designed and qualified to Class IE criteria.
Response
Instrumentation systems used to initiate containment purge isolation are qualified to Class IE criteria.
(6)
It is the NRC's position that the overriding or resetting of the ESF actuation signal should not cause any equipment to change position.
Response
The requirement that overriding or resetting ESF actuation signals should not cause any equipment to change position is undergoing review and verification as required by IE Sulletin No. 80-06.
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