ML19296D287
| ML19296D287 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/22/1980 |
| From: | Trimble D ARKANSAS POWER & LIGHT CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19296D288 | List: |
| References | |
| 2-1510, NUDOCS 8003030250 | |
| Download: ML19296D287 (2) | |
Text
y
[
2 L
~
s ARKANSAS POWER & LIGHT COMPANY POST OmCE DOX 551 UTTLE ROCK. ARKANSAS 72203 (501)371-4000 February 22, 1980 2-020-08 Director of Nuclear Reactor Regulation ATTN:
Mr. R. W. Reid, Chief Operating Reactors Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Containment Purge System (File:
2-1510)
Gentlemen:
In response to your request of January 3,1980, the following is provided.
1.
ESFAS OVERRIDING Overriding of an Engineered Safeguards Feature Actuation System (ESFAS) signal is not a design feature for the ANO-2 Containment Purge / Vent System.
2.
ECCS BYPASS CONTROLS A trip channel bypass is provided for each type trip for each of the four ESFAS channels to be employed for maintenance and testing.
An electrical interlock allows only one channel for any type trip to be bypassed at one time.
The ESFAS pressurizer pressure bypass is provided to allow plant de-pressurization without undesired actuation of ESF equipment.
This bypass must be initiated manually by switches in each protective channel and is possible only below 400 psia.
This bypass is automat-ically removed if pressurizer pressure rises above 500 psia.
3.
ECCS BYPASS ANNUNCIATION All bypasses are annunciated visually and audibly to the operator.
4.
CONTAINMENT ISOLATION Our letters of January 18, 1980, and January 31, 1980, documented our method of compliance with Category A Lessons Learned requirement 2.1.4 of NUREG-0578. We presently have the diverse actuation signals of high containment pressure and low RCS pressure for containment isola-tion.
Both of these signals are derived from safety grade equipment.
8 3030 250 MEMOE A MtOOLE SOUTH UTILITIES SYSTEM c>
2-020-08 February 22, 1980 Containment isolation on high radiation, to our knowledge, is not re-quired and is not provided in our design.
No modifications are expected to add this isolation signal due to the small number and low probability of events which might lead to high radiation prior to high containment pressure or low RCS pressure.
5.
ESFAS The instrumentation and control system provided to initiate containment isolation, ESFAS, is designed and qualified as safety grade equipment.
6.
AUTOMATIC REOPENING The overriding or resetting of the isolation actuation signal does not causs the automatic reopening of any isolation / purge valve, as delineated in our letters of January 18 and January 31, 1980.
Attached are three copies of the schematic drawings for the ANO-2 purge and vent system (E-2369 and E-2370).
Very truly yours,
- f. f David C. Trimble Manager, Licensing DCT: ERG: ska Attachments