ML20236K143

Interim Part 21 & Deficiency Rept Re Inductive Current Interruptive Capacity of Solid State Protection Sys Motor Driven Relay Contacts.Shunt Suppression Device Will Be Added to Solenoid

ML20236K143
Person / Time
Site:	Vogtle
Issue date:	11/02/1987
From:	Gucwa L GEORGIA POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
REF-PT21-87, REF-PT21-87-201-000 PT21-87-201, PT21-87-201-000, SL-3508, NUDOCS 8711090113
Download: ML20236K143 (2)

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Georgia Poor Ccmpanyn ,

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- A' 333 Piedmont Avenue . 1

"%+ At! nti, Georgia 30308 '

y; T;lephona 404 526-6526 -

' Mamng Address:

Fbst ottice Box 4645 '

' Atlanta, Georgia 30302 L

Georgia Power I"*

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X7GJ17-V100 November 2, 1987 U. S.' Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 PLANT V0GTLE - UNIT 1 i NRC DOCKET 50-424 0PERATING LICENSE'NPF-68.

, SOLID STATE PROTECTION' SYSTEM RELAYS

. Gentlemen:

In letters GN-1266, dated December 29, 1986, and GN-1313, dated

. January 10, 1987,- Georgia Power Company described a concern involving the inductive current interruptive capacity of solid state protection system (SSPS) motor- driven relay (MDR) contacts. This condition was determined to exist on those circuits where the magnitude of the inductive current interruptive requirement for "in-line" process solenoid valve coil control circuits exceeded the relay contact rating. Specifically, the concern. involved ' safety related SSPS and Main Steam Isolation Valve

, (MSIV) circuits, and non-safety related Diesel Generator Building heating, ventilation and air conditioning circuits. Letter GN-1313 described this concern, identified it as a reportable condition pursuant to 10 ' CFR 50.55(e) and 10 CFR 21, and justified plant operations with this condition for a period of at least the first fuel cycle (approximately two years). A commitment was made to provide a description of any required long term corrective action to the NRC no later.than' November 1, 1987.

Georgia Power has elected to make hardware modi fications to the F Effected circuits to resolve this issue. 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 modifications will be completed on Unit 1 prior to startup of the second cycle of operation.

" N 871'1090113 871102 PDR ADOCK 05000424

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U. S. Nuclear Regulatory Commission

- Noveniber 2,1987.

Page Two

. Should. you have any questions in this regard, please contact this 4 office at any time, i Sincerely, pA  %

L. T. Gucwa

.LHS:LTG:ju c: Georaia Power Comoany:

Mr. R. E. Conway Mr. G. Bockhold, Jr.

Mr. L. T. Gucwa Mr. .J. E. Swartzwelder

.Mr. C. H. Hayes GO-NORMS Southern Comoany Services.

Mr. R. A. Thomas i Mr. J..A. Bailey-

, U. S. Nuclear Reaulatory Commissi'on. Hashinaton. D. C.

Ms. M. A. Miller, Licensing Project Manager, NRR (2 Copies)

.- U. S. Nuclear Reaulatory Commission. Reaion II 1 Dr. J. N. Grace, Regional Administrator ~

Mr. J. F. Rogge, Senior Resident Inspector-0perations, Vogtle Shaw. Pittman. Potts & Trowbridge Mr. B. H. Churchill, Attorney-at-Law. i l

Troutmac. Sanders. Lockerman & Ashmore Mr. A. H. Comby. Attorney-at-Law '

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