ML18030A154

Interim Deficiency Rept Re Excessive Voltage Drops in Ac Motor Operated Valve Controls Circuits Er 100450 & Er 100508.Caused by Sizeable Resistance of Small Control Cable Long Lengths.Alternatives Being Evaluated

ML18030A154
Person / Time
Site:	Susquehanna
Issue date:	10/20/1980
From:	Curtis N PENNSYLVANIA POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, PLA-560, NUDOCS 8010240456
Download: ML18030A154 (4)

Text

REGULATORY, %FORMATION DISTRIBUTION SY EM (RIOS)

ACCESSION NBR: 8010200056 OOC i'DATE t 80/10/20 NOTARIZED: NO DOCKET FACIL!50 387 Susquehanna Stea~ Electric Stationg Unit ir Pennsy'Iva 50 388 Susquehanna Steam Electric Stationi Unit 2r Pennsylv 050003 AUTH, NAME AUTHOR AFFILIATION CURTIS' ~ H ~ Pennsylvania Poser 8 Light Co, REC IP ~ NAME RKC I PIKNT AFFILIATION ,I li GRIERg B,H, Region ii Philadelphiar Office of the Director

SUBJECT:

Interim deficiency rept re excessive vo,ltage drops in ac motor. operated valve controls circuits KR 100450 8 ER 100508;Caused by sizeable resistance of small control cable long lengths.Alternatives being evaluated>

DISTRIBUTION CODE: B019S COPIES RKCEIVKDeLTR I, ENCL 6 SIZE:

TITLE: Construction Deficiency Report- (10CFR50.55E)

NOTES:Send I8K 3 copies FSAR 8 all amends. 05000387 Send ILE; 3 copies FSAR L all amends. 05000388 RECIPIENT COPIES COPIES

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I TWO NORTH NINTH STREET, ALLENTOWN, 'PA: 18101 PHONEs (215) 821 ~ 5151 NORMAN W. CURTIS Vice President-Engineering IL Conairuction-Nuclear 821-5381 October 20, 1980 Mr. Boyce H. Grier Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 SUSQUEHANNA STEAM ELECTRIC STATION INTERIM REPORT OF A DEFICIENCY ON EXCESSIVE VOLTAGE DROPS IN AC MOTOR OPERATED VALVE CONTROL CIRCUITS ERs 100450/100508 FILE 840-4 PLA-560

Dear Mr. Grier:

This letter serves to confirm information provided by telephone to NRC Region I Inspector Mr. J. Durr by Mr. R. A. Schwan of PPGL on September 18, 1980. During that conversation Mr. Durr .:was advised that the subject con-dition was under evaluation for reportability under the provisions of 10CFR50.55(e).

The deficiency involves excessive voltage drops in the control circuitry of the motor starters for some motor operated valves (MOVs). (Motor starters are devices which provide the control of power to motors.) For AC powered MOVsr the motor starter operating coils are supplied via a control transformer tapped off the MOV power supply. Multiple switches and relay contacts are wired in this control circuit to make up the control logic for the MOV.

At Susquehanna SES, excessive voltage drops occur in motor starter control cables when size 2, or larger, starters for motor operated valves are energized.

These voltage drops, which are severe enough to prevent motor starter operation, are caused by the sizeable resistance (several ohms) of long lengths (several thousand Eeet) of small (114 cu) control cable.

Twenty-two (22) size 2 or larger motor starters are located in Class lE safety systems such as Reactor Recirculation and Residual Heat Removal and must be checked to determine if excessive voltage d'rops occur.

Since these valves are required to operate to mitigate a design basis event, the aforementioned failure to operate represents a significant deficiency in design. Therefore, the deficiency is deemed reportable under 10CFR50.55(e).

Further, since the details of this report provide." information relevant to the reporting requirements of 10CFR21, this correspondence is considered to also discharge any formal responsibility PPGL may have for reporting in compliance thereto. Ao(

'gal SI0$ 0g40 PENNSYLVANIA POWER Es LIGHT COMPANY

\

Mr. Boy'ce'.5. Grier October 20, 1980 PPGL Engineering is in the process of evaluating several alternatives in order to determine an optimum course of action. We currently estimate that a final report of'he deficiency and the corrective action taken will be transmitted to you in January, 1981.

Very truly yours, N. W. Curtis Vice President-Engineering a Construction-Nuclear FLW:mcb cc: Mr. Victor Stello (15)

Director-Office of Inspection 6 Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555

<Mr. G;--McDonald,Director.

Office of Management Information 6 Program-Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Robert M. Gallo U. S. Nuclear Regulatory Commission P. O. Box 52 Shickshinny, Pennsylvania 18655