ML19340C107

Deficiency Rept Re Limitorque Valve Operator Malfunctions.No Stem Protectors Have Been Found to Cause Valve Malfunctions. Valve Testing Continuing.Final Rept Will Be Submitted by 810117

ML19340C107
Person / Time
Site:	Grand Gulf
Issue date:	11/03/1980
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
80-005-03L, 80-5-3L, AECM-80-271, NUDOCS 8011140001
Download: ML19340C107 (2)

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unihnaammal MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P. O. B O X 16 4 0, <J A~C K S O N, M I S S I S S I P P I 3 9 2 0 5

. ?!" 4 MO : 0 0 JAjj$Mg}f November 3, 1980 20 005-034 j .

Office of Inspection & Enforcement U. S. Nuclear Regulatory Co= mission Region II 101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303 1

Attention: Mr. J. P. O'Reilly, Director

Dear Mr. O'Reilly:

i

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 {

Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/08, Status Report #3, L I

Limitorque Valve Operator Malfunctions AECM-80/271

References:

1) AECM-80/74, 4/11/80

2) AECM-80/165, 7/23/80 i l

On March 14, 1980, Mississippi Power & Light Company notified l Mr. F. Cantrell, of your office, of a Potentially Reportable Defi-ciency site. (PRD) at the Grand Gulf Nuclear Station (GGNS) construction The deficiency concerns malfunctions of Li=itorque valve operators.

Our investigation into this matter has not been completed. In- '

formation supplementing in the attached our previously submitted reports is ccntained status report.

an i submit a final report by JanuaryWe 17,expect 1981. to determine reportability Yours truly, l Ol A 5 fpr J. P. McGaughy, Jr. ,

ATR:st I

Attachment "

cc: Mr. N. L. Stampley Mr. R. B. McGehee Mr. Victor Stello, Director l Mr. T. B. Conner Division of Inspection & Enforcament '

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

l 3140001 Member Middle South utilities System # ~' #

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• Attachment to AECM-80/271

, Page 1 of 1 I. Description of Deficiency During testing of the Condensate System (N19) non-safety related valves malfunctioned. These were identified as Limitorque Valve operators (Type SNB) 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 electrically, the stem protector acts as a jam-nut against the stem lock nut which causes the torque switch to trip the motor on high opening torque.

II. Approach to Resolution of Deficiency The Constructor's Checkout & Turnover Organization (CTO) will stroke Unit I valves to determine whether or not stem protectors interfere with proper valve operation. Results of this testing will be transmitted to the Architect / Engineer for evaluation.

A decision to investigate Unit II valves will be made en comple-tion of this evaluation.

III. Status of Proposed Resolution The Checkout & Turnover Organization has completed testing of 50 Unit I safety related motor operators and has found no stem protectors causing valve malfunctions. The CTO is continuing to test valves as they are released by the constructor.

IV. Reasons for Delaying Final Report All valves have not been released by the Constructor to the CTO.

V. Projected Final Report Submittal Date The final report will be submitted on completing the testing of the valves. It is estimated this will be accomplished by January 17, 1981.

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