ML20084A903

AO 50-244/75-04:on 750213,during Performance of PT-20,MSIV Solenoid Trip Test,One Air Supply Solenoid Valve Failed to Operate When Tested.Caused by Flat Spot or Burr on Latching Pin.Linkage Adjusted

ML20084A903
Person / Time
Site:	Ginna
Issue date:	02/21/1975
From:	White L ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20084A905	List: ML20084A903 ML20084A914
References
AO-50-244-75-04, AO-50-244-75-4, NUDOCS 8304050674
Download: ML20084A903 (3)

Text

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. ROCHESTER GAS AND ELECTRIC CORPORATION e 69 EAST AVENUE, ROCHESTER, N.Y.14649 LEON D. WHITE. JR. Tatep o%c vlCE PatssottqY Aata coce rie 54G 2700 February 21, 1975 9 9 d' 4 Mr. James P. O'Reilly, Director e.

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U. S. Nuclear Regulatory Commission - gIS7 _

Office of Inspection and Enforcement E Rt ,hh,[s ,$g 2 4^ .

Region I *IM'y,'

631 Park Avenue 9 d King of Prussia, Pennsylvania 19406 m b

Subject:

Abnormal Occurrence 75-04, Failure of solenoid test valves to operate on "A" Main Steam Isolation Valve during surveillance test R. E. Ginna Nuclear Power Plant, Unit No.1 Docket No. 50-244

Dear Mr. O'Reilly:

In accordance with Technical Specifications, Article 6.6.2a, the attached report of Abnormal Occurrence 75-04 is hereby submitted. 'Two additional copies of this letter and the attachment are enclosed.

Very truly yours, s

L. D.~ White , Jr.

Attachment cc: Mr. Donald F. Knuth (40) 2172 8304050674 750221 -*

PDR S ADOCK 05000244 PDR_.

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o 1.

R7 port Numbst: 50-244/75-04 o

!O 2a. Report Date: February 21, 1975 2b. Occurrence Date: February 13, 1975

3. Facility: R. E. Ginna Nuclear Power Plant, Unit No.1 l

4. Identification of Occurrence:

This abnormal occurrence is defined by Technical Specifications Article 1.9d: Failure of one or more components of an engineered safety feature or plant protection system that causes or threatens to cause the feature or system to be incapable of performing its intended function.

5. Conditions Prior to Occurrence:

. The unit was operating at a steady state level of 100 percent power.

l 6. Description of Occurrence:

l l During the performance of the surveillance test, PT-20, " Main l Steam Isolation Valve Solenoid Trip Test", upon actuating the Main Control l Board (MCB) control switch for the "A" Steam Line Isolation Valve, one of the two series air supply solenoids did not trip to the closed position although the coil armature did pick up.

An immediate retest resulted in the repeated failure of the same air supply valve to trip and in addition, one of the air exhaust valves failed to operate at this time. The MCB control switch operation and necessary resets were then performed several times with similar and erratic failure results . Instrument and Control Repairman personnel witnessed the operation and then made a minor adjustment to the latching mechanism.

Following this the test was satisfactorily performed five times without l failure.

I l The test of the "B" Main Steam Isolation Valve trip was completed l without incident.

l l 7. Designation of Apparent Cause of Occurrence:

In all cases the coil armature operated as required. The failure

! of the "A" solenoid valves was in their mechanical operation. It is l

believed that a flat spot or burr may have developed on the latching pin of the air supply valve trip mechanism. Rotation of this pin from its fixed position produced the successful retesting. The exhaust valve trip mechanisms appeared stiff in action and responded properly after the several test operations.

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AOR 50-244/75-hnt'd. .2

8. Analysis of Occurrence:

1 .

There was no hazard to plant personnel or the public. Due to the

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i arrangement of the four solenoid valves, failure of the two solenoid valves

) in question would not have prevented closure of the "A" Main Steam l Isolation valve.

i The solenoid valves are tested every two months and had operated properly during the last three tests of August, October and December of i 1974. .

1 j 9. Corrective Action: -

! As described above, a reposition of the latching pin and the exer-cising'of the mechanisms to overcome any linkage friction or binding of i valve packings apparently corrected the problem.

1 ..

i The PORC met at 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> on February 13,1975 to discuss the -

l failure and recommended that the test be re'peated prior to our scheduled j outage on March 15, 1975 to determine the amount of maintenance to be-

! performed on this system during the shutdown.

]

l 10. Failure Data:

i

! Since the valves were mounted on the containment wall to reduce l

a vibration problem, there has been-one other dissimilar failure of these

i. .

solenoids prior to this occurrence. This failure occurred on June 26,1974' i

j. and was reported as Abnormal Occurrence 74-11.

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i The valves are Laurence Solenoid Valves, Cat. # 125434W (air j vent valves), and Cat. # 110114W (air supply valves) for 125 psi, air.

l They are manufactured by the R. G. Laurence Company, Inc. , Tenafly, I New Jersey 07670.

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