ML19331B630

Interim Deficiency Rept Re Contact & Indication Malfunction of Series 20,Type PR-20 Electro Switches.Evaluation Incomplete.Determination of Reportability & Final Rept Will Be Sent by 801028

ML19331B630
Person / Time
Site:	Grand Gulf
Issue date:	07/30/1980
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:
References
AECM-80-172, NUDOCS 8008120514
Download: ML19331B630 (3)

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CA _U MISSISSIPPI POWER & LIGHT COMPANY i -] Helping Build Mississippi Em M P. O. S C X 16 4 0, J A C K S O N MIS SIS SIP PI 3 9 2 0 5 sve:. EAR PACoUCTioN CEPARTMENT July 30, 1980 Office of Inspection & Enforcement U. S. Nuclear Regulatory Cet: mission Region II 101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Director

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/38, Status Report, Electro Switch Malfunctions AECM-80/172 On July 2, 1980, Mississippi Power & Light notified Mr. F.

Cantrell of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency con-cerns contact and indication malfunctions of Electro Switches, Series 20, Type PR-20.

The scope of our investigation has been expanded to include an additional problem with Electro Switches. Our investigation and evaluation have not been completed. Details are in the attached status report.

We expect to determine reportability and submit a final report by October 28, 1980.

Yours truly, Jg' b ,w0J (-

k J. P. McGaughy, Jr.

Assistant Vice President, Nuclear Production I

AIR:st Attach =ent 80081205/#[ Member Middle South uenicies System

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MIENCCIPPI POWER O LIGHT COMPANY I

l Mr. J.'P. O'Reilly AECM-80/172 NRC Page 2 t

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cc: Mr. N. L. Stampley Mr. R. B. McGehee Mr. T. B. Conner i

j Mr. Victor Stello, Director -

g Division of Inspection & Enforcement ..

U. S. Nuclear Regulatory Commission Washington, D.C. 20555 i

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4 Attach::st to AECM-80/172

' Pega 1 of 1 STATUS REPORT. PRD-80/38 I. Descriotion of Deficiency

a. Electro Switches, Series 20, Type PR-20, supplied by General Electric, shewed contact and indication =alfunctions during system testing. The malfune:1cn is when the switch is turned to the STOP position and released quickly, the internal cen-tact arrange =ent is such that the AUTO fres START position contacts close.rather than the AUTO frca STOP positica centacts.

A similar =alfunction occurs when the switch is quickly re-leased frc= the START position. Three (3) sweiches (No. 53A, S33, 53C) which experienced this =alfunction are used in the Residual Heat Removal (RER) System.

b. Electro Switch, GE Switch Number S3A, contains an additienal probles with the internal contact arrange =ent of the switch.

The contacts are arranged such that turning the switch to the STOP positien vould start the RER pu=p and vice versa. This switch controls RER Pump "A". ,

II. Safety Implications The evaluation as to the safety implicatiens has not been ecmpleted by cur NSSS supplier.

III. Corrective Action Taken Corrective actions are centingent on the results of the evaluation of safety i=plications.

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