ML19262B983
| ML19262B983 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/10/1980 |
| From: | Trimble D ARKANSAS POWER & LIGHT CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| 1-010-08, 1-10-8, NUDOCS 8001220376 | |
| Download: ML19262B983 (2) | |
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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 C5C ) 371-4000 January 10, 1980 1-010-08 Director of Nuclear Reactor Regulation Attention:
Mr. R. W. Reid, Chief Operating Reactor Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Control Room Toxic Gas Protection (File: 3600, 1510)
Gentlemen:
In response to your letter on this subject dated December 14, 1979, which requests chlorine detectors, automatic isolation and a reduction of the control room isolation air exchange rate, the following is provided:
1)
Request:
Install quick-response chlorine detectors in the fresh air inlets.
Response
Redundant, quick acting chlorine detectors are prescatly in place in the. control room fresh air inlet.
2)
Request:
Isolate control room automatically on high chlorine alarm within ten (10) seconds.
This is the time interval between the chlorine concentration exceeding 5 ppm at the isolation dampers and the time the dampers are completely closed.
1785 193 8001220 3 76 fV'E MDE A MC1E ECUTH UTILITiE S SYS*E *."
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1-010-08 Mr. R. W. Reid January 10, 1980
Response
The chlorine detectors' signals initiate automatic isolation of the ANO 16 2 common control room and provide an audible alarm in both sections of the control room in case of high chlorine gas concentration.
The detectors are able to detect and signal a step increase in chlorine concentration of 0 to 15 ppm within 5 seconds (based on 66% response).
Control room isolation is accomplished within 5 seconds after detector trip.
These detectors are described in Section 9.4.1.1.2 of the ANO-2 FSAR, and the design criteria described in this response has been reviewed and approved by the Staff (ANO-2 Safety Evaluation Report, Section 9.5.1, page 9-7).
Based on this approval, we propose that the ANO-1 criteria be consistent with that of ANO-2.
- 3) Request:
The control room isolation air exchange rate should be re-duced from 3 to 0.06 air changes per hour.
Response
In the event of high chlorine, the combined ANO-16 2 control rooms are isolated from both outside air and adjacent rooms.
The control room emergency air filtration system is based on a minimum of three (3) room air changes per hour for the combined control room volume.
A higher recirculation rate of fifteen (15) air changes per hour is provided by the emergency air conditioning system.
This system is described in the ANO-2 FSAR, Section 9.4.1, and has been reviewed and approved by the Staff (ANO-2 SER Section 9.5.1, page 9-7).
Based on this approval, we propose that the ANO-1 criteria be consistent with that of ANO-2.
Very truly yours,
.0we2 C. "LdA David C. Trimble Manager, Licensing DCT: ERG:bj m 1785 194'
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