ML19330A864

Forwards Status Rept 2 of Potentially Reportable Deficiency Re Malfunctions of Limitorque Valve Operators.Caused by Excessive Threading of Stem Protectors.Final Rept by 801103

ML19330A864
Person / Time
Site:	Grand Gulf
Issue date:	07/23/1980
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:
References
AECM-80-74, NUDOCS 8007290666
Download: ML19330A864 (2)

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MISSISSIPPI POWER & LIGHT COMPANY

] Helping Build Mississippi EmetinHMdB P. O . 8 0X 164O. J AC K S O N MIS SIS SIP PI 3 9 2 05 NuctzAn PacoucnoN oEPARTMENT July 23, 1980 Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission -

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 l Docket Nos. 50-416/417 I File 0260/15525/15526 PRD-80/08, Status Report #2, Limitorque Valve Operator Malfunctions AECM-80/165 Referenca: AECM-80/74, 4/11/80 on March 14, 1980, Mississippi Power & Light notified Mr. F.

Cantrell of your office of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site.

The deficiency concerns malfunctions of Limitorque valve opera-tors. ,

i Our investigation into this matter has not been completed.

Preliminary infor=ation is provided in the attached status report.

We expect to determine reportability and submit a final report by '

November 3, 1980.

Yours truly,

'y; D J. P. McGaughy, Jr.

Assistant Vice President, Nuclear Production [

ATR:st l

Attachment '

cc: Mr. N. L. Stampley Mr. Victor Stello, Directog4 THIS COPY FOR Mr R. 3. McGehee Division of Inspection & Enforcement Mr. T. 3. Conner U. S. Nuclear Regulatory Ccesission Washington, D.C. 20555 800729O N h 3 Member Middle South utitities System

Attachm:nt to AECM-80/165

. Peg 2 1 of 1 o

STATUS REPORT //2 FOR PRD-80/08 I. Description of Deficiency During testing of the Condensate System (N19) non-safety related valves malfunctioned. These were identified as Limitorque Valve .

operators (Type SMB) with valve stem protectors. The valve stem protectors caused the motor operator to malfunction which, in turn, prevented the valve from opening to its maximum opening position.

The cause of the malfunction was excessive threading of the stem.. protector. This allowed the stem protector to be screwed too far into the operator. When the valve is operated elec-trically, the sten protector acts as' a jam-nut against the sten lock nut which causes the torque switch to trip the motor on high opening torque.

11. Safety Implications Although the malfunction occurred on a non-safety related valve, the generic implications are being investigated since the same type valve operators are used in safety-related systems.

III. Corrective Actions Corrective actions are to be developed on completion of the in- -

vestigation and an evaluation of the results. Bechtel MCAR GGNS-65 is tracking this condition.

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