ML20236J537
| ML20236J537 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/29/1987 |
| From: | Rice P GEORGIA POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| REF-PT21-87, REF-PT21-87-202-000 GN-1407, PT21-87-202, PT21-87-202-000, NUDOCS 8711060160 | |
| Download: ML20236J537 (2) | |
Text
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- d'M'3'SOH Wgtiv Prowct October 29, 1987 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk File:
X7BG03-M134 Washington, D. C.
20555 Log:
GN-1407
Reference:
Vogtle Electric Generating Plant - Unit 2; 50-425; Solid State Protection System Relays Letters GN-1266 dated 12/29/86, GN-1313, dated 1/10/87 Gentlemen:
In the referenced correspondence, Georgia Power Company described a concern involving the Solid State Protection System (SSPS) motor driven relay (MDR) contacts inductive current interruptive capacity.
Correspondence GN-1313, dated 1/10/87 described this
- concern, identified it as a reportable condition pursuant to 10CFR50.55(e) and 10CFR21, and justified the plant condition to be adequate for at least the first fuel cycle (approximately two years).
Any long term corrective action required was committed to be provided to the NRC no later than November 1,
1987.
This condition was previously determined to exist on safety related SSPS and MSIV ci rcui ts, and non-safety-related Diesel Generator Building HVAC circuits.
Specifically, those circuits where the magnitude of the inductive current interruptive requirment for "in-line" process solenoid valve coil control circuits exceeded the relay contact rating.
Georgia Power Company has elected to make hardware modifications to the affected circuits rather than establish the long term life of the MDR's in an application that exceeds their rated inductive current interruptive capacity.
To reduce the effects of the inductive loading on the affected current interrupting contacts, a shunt suppression device will be added across the solenoid and a resistance-capacitance shunt network will be added across the relay contacts.
Implementation of this modification assures that the design will be adequate for the life of the plant.
The safety-related SSPS and MSIV circuit modi fications will be completed on Unit 2 prior to fuel load, commensurate with the Unit 2 construction schedule.
The Unit 1 response on this issue will be made in a separate letter.
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8711060160 G71029 DR ADOCK 0500 5
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File:. X78G03-M134
, Log: GN-1407 j
.Page two
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This correspondence contains no proprietary information and may be placed -in the NRC Public Docurnent Room.
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1 P. D. Rice PDR/wkl xc:
H. G. Baker, Jr.
D. R. Altman L. T. Gucwa 1
R. E. Conway J. A. Bailey C. W. Hayes J. P. O'Reilly G. Bockhold, Jr.
R. W. McManus R. H. Pinson G. R. Frederick Sr. Resident (NRC)
E. D. Groover J. F. D'Amico D. H. Smith (0PC) l C.
T.,
Moore G. A. McCarley NORMS J. E. Joiner (TSLA) i 3
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