ML19211A441

Forwards Request for Addl Info to Complete Evaluation of Electrical Override/Bypass Aspects of Containment Purge Sys

ML19211A441
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/19/1979
From:	Lainas G Office of Nuclear Reactor Regulation
To:	Reid R Office of Nuclear Reactor Regulation
References
TAC-42588, NUDOCS 7912180198
Download: ML19211A441 (2)

Text

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NUCLEAR REGULATORY COMMISSION E

WASHINGTON, D. C. 20555 N

NOV 1 9 1079 HEMORANDUM FOR:

R. Reid, Chief, Operating Reactors Branch #4, 00R FROM:

G. Lainas, Chief, Plant Systems Branch, D0R

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - CONTAINMENT PURGE SYSTEM - ARKANSAS NUCLEAR ONE, UNIT 2 (TAC 10212)

Plant Name: Arkansas Nuclear One, Unit 2 Docket No.:

50-268 Project Manager:

G. Vissing Review Status: Awaiting Information Plant Systems Branch has identified the enclosed additional information as being required in order that we can complete our evaluation of the electrical override / bypass aspects of the containment purge matter.

G. Lainas, Chief Plant Systems Branch Division of Operating Reactors

Enclosure:

As stated

Contact:

R. Scholl X-27162 cc w/ enclosure:

D. Eisenhut D. Shum W. Ganmill J. Kerrigan 1607 34)~

L. Nichols G. Knighton G. Lainas V. Noonan E. Reeves F. Witt E. Adensam J. Zudans G. Vissing R. Scholl D. Tondi V[u p t 6 0 l T b

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ENCLOSURE g

i REQUEST FOR ADDITIONAL INFORMATION FOR CONTAINMENT PURGE SYSTEM AND CONTAINMENT VENTING SYSTEM FOR ARXANSAS NUCLEAR ONE, UNIT 2

_Dy '.ET NO. 50-368 1.

Your response does not adequately address the following areas.

Please discuss how your design confonns with each:

1 - The overriding

• of one type of safety actuation signal (e.g., radiation) should not cause the blocking of any other type of safety actuation signal (e.g., pressure) to the isolation valves.

2 - Sufficient physical features (e.g., key lock switches) should be provided to facilitate adequate administrative controls.

3 - The system-level annunciation of the overridden status should be provided for every safety system impacted when an override is active.

4 - Diverse signals should be provided to initiate isolation of the containment ventilation system. Specifically, containment high radiation, safety injection actuation, and containment high pressure should automatically initiate Containment Ventilation Isolation (CVI).

5 - The instrumentation and control systems provided to initiate CVI should be designed and qualified as safety-grade equipment.

6 - The overriding or resetting

• of the isolation actuation signal should not cause the automatic reopening of any isolation / purge valve.

2.

Provide the schematic drawing of your purge and vent systen.

• The following definitions are given for clarify of use in this issue:

Override - the signal is still present, and it is blocked in order to perfonn a function contrary to the signal; Reset - the signal has come and gone, and the circuit is being cleared to return to the nonnal condition.

1607

$46