ML20084G783
| ML20084G783 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 09/07/1973 |
| From: | Amish K ROCHESTER GAS & ELECTRIC CORP. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20084G779 | List: |
| References | |
| REF-SSINS-6820 IEB-73-02, IEB-73-2, NUDOCS 8304220334 | |
| Download: ML20084G783 (1) | |
Text
. _ _
i 6
C o
/
t is September 7,1973 Mr. James P. O'Reilly, Director Directorate of Regulatory Operations Region I U. S. Atomic Energy Commission 631 Park Avenue King of Prussia, Pennsylvania 19406
Subject:
R. E. Ginna Nuclear Power Plant, Unit No.1 RO Bulletin 73-2 Docket No. 50-244
Dear Mr. O'Reilly:
This letter is in response to your Regulatory Operations Bulletin 73-2, dated July 18, 1973, which requested us to review the design of the control circuit for the containment ventilation system isolation valves to determine whether the failure of a single control switch could result in the simultaneous failure of the redundant supply valves or redun-dant exhaunt valves and provide your office with our findings within 45 days of e receipt of your letter.
A review of our electrical prints indicates that each valve may be indi-vidua!!y opt ated by a separate main control board switch: consequently, a single control switch failure could not render the associated redundant valve inoperable.
The containment ventilation isolation trip relay contacts are series connected with the individual switch contacts supplying D. C. power to the respective isolation valves actuating solenoids. This configur-ation ensures that all of the concerned containment ventilation isolation valves will close upon receipt of a containment ventilation isolation signal regardless of any postulated switch being inoperable.
Very truly yours,
V n
s
!eith W. Amish K
xc: Mr. J. F. O' Leary 050h0k4 i
PDR A