ML20085C872

AO 50-254/74-37:on 741108,ball Valve for TIP Machine 5 Failed in Open Position.Caused by Failure of Spring & Malfunction of Limit Switch.Spring Tension & Limit Switch Readjusted

ML20085C872
Person / Time
Site:	Quad Cities
Issue date:	11/18/1974
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085C873	List: ML20085C872 ML20085C885
References
AO-50-254-74-37, NJK-74-390, NUDOCS 8307130179
Download: ML20085C872 (3)

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November 18, 1974 Mr. John F. O' Leary, Director Directorate of Licensing Regulation U.S. Atomic Energy Commission Washington, D.C. 20545

REFERENCE:

Quad-Cities Nuclear Power Station Docket No. 50-254, DPR-29 Anpendix A, Sections 1.0.A.2, 3.7.D.1, 3.7.D.3,

& 6.6.B.l.a.

Dear 'tr. O' Leary:

Enclosed clease find Abnormal Occurrence Report No. AO 50-254/74-37 for Quad-Cities Nuclear Power Station. This occurrence was previously recorted to Region III, Directorate of Regulatorv Operationn by telephone on 'lovember S , 1974 and to vou and Region III, Directorate of Rcqulatory Operations by telecopv on November 8, 1974.

This report is submitted to you in accordance with the require-ments of Technical Specification 6.6.B.l.a.

Very truly yours, CO'010NWEALTH EDISON CO?tPANY QUAD-CITIES NUCLEAR POWER STATION f' .

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• w,/ /w.'t:Wh M. J. Kalivianakis Station Sunerintendent NJK/RAR/saa cc: Region III, Directorate of Regulatorv Operations

-J. S. Abel 8307130179 741118 1 ' Q  ;

Alvd-PDR ADOCK 05000254 4 S PDR l COPY SENT REGJON I' 2

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REPORT NUMBER:

o. AO-50-254/74-37 o

REPORT DATE: November 18, 1974 O'CCURRENCE DATE: November 8, 1974

', FACILITY: Quad-Citics Nuclear Power Station Cordova, IL 61242 IDENTIFICATION OF OCCURRENCE:

.The ball valve for TIP Machinc #5 of Unit One failed in the open position.

L CONDITIONS PRIOR TO OCCURRENCE:

Tne unit was' in the RUN Mode at a steady state power level of 2261  ;

MMt and 735 MWe. P DESCRIPTION OF OCCURRENCE: ,

.On November 8, 1974.at 0715 hours0.00828 days <br />0.199 hours <br />0.00118 weeks <br />2.720575e-4 months <br />, while making a normal curvey of his control pancia, the Unit One operator discovered that the ball valve for TIP Machine #5 was in the open position. Operating the manual control switch on the TIP Drive Control Unit failed to close the hal1 valvo. The Instrument Maintenance Department was notified and preparations were made to make an entry into the Unit One TIP cubicle. After a preliminary attempt to repair the ball valve in place failed, the t,all valve wa%, declared inoper-able and at' ll50 hours on Novencer 8, an orderly shutdown at the rate of 20 MWo por hour was initiated. .The control key for the shear valve was positioned in the control room for immediate use if necessary. These actions ucre in comoliance with sections

- 3.7.D.1 and 3.7.D.3 of the Technical Specifications.

DESIGN 4 TION OF APPARENT CAUSE OP OCCURRENCE: ~

Component f ailEre - The cause of the occurrc6ce was a combination

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of two component failures. The valve is solenoid-operated to the open position and spring loaded to the closed position.

There arc limit switches which provide open and closed indica-tions to the control room. The spring was failing to return the ball valvo conpletely to the closed position. Also, after this problem was initially corrected, the closed indication limit switch was not actuating properly, e

ANALYSIS OF OCCURREUCE:

Although the open ball valve was discovered at 0715 hours0.00828 days <br />0.199 hours <br />0.00118 weeks <br />2.720575e-4 months <br /> on November 8, 1974, it is not known preci.scly when the failure occurred. The latest written record of TIP Machine #5 being

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operated was at >150.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> on November 5,1974. The actions of the operator-afte'r the discovery-were adecuate. Under accident conditions, with thc.drywell pressurized to 62 psig, the flow through thp open ponctration would have been 72.1 SCFM.

Since the Standby Gas Treatrent System would automatically start in the event of a loss-of coolant accident, this loakage would be. processed through it. This.72.1 SCPM represents only a small percentage of the. rated flow of the SBGT system, thus ~chere would u.

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AO-E C,- >5 4 /7 4 ( ()Movember18, 1974 have been no significant amounts of radioactive materials rcleased, nor would the public health and safety have been

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endangered.

CORRECTIVE ACTIOM:

On November 8,~ 1974 at the time that the shutdown was initiated, the instrument mechanics removed the failed ball valvo and capped the primary containnent penetration for TIP Machine #5. The ball valve was partially dismantled and inspected for an accumulation of the dry type lubricant used in the TIP tubes. This had been a cause of past ball valve failures. No accunulation was found.

The valve was actuated on the bench and it was noticed that the valve was not returning completely to the closed position. The spring tension was adjusted. The valve was re-installed in the unit and functionally tested. It was then discovered that the open light remained on. After additional repair attempts failed, the valve was lef t out of the unit and the tube capped until November 12, 1974. The unit load reduction was terminated at 385 MWo.

On 11ovember 12, 1974, the ball valve was completely dismantled and it was discovered that the limit switch for the closed position was not actuating. All moveable parts of the valve vere cleaned and lubricated, the spring tension was re-adjusted, and the limit switch uns adjusted. The ball valve was re-installed and functionally tested saticfactorilv.

FAILURE DATA:

EOUIPI!EMT IDE'lTIPICATIOM:

thElpment Picco Number 700-733. Solenoid operated ball valve conforming to General Electric Drawing ll2C2391P001.

RECORD OF FAILURES:

No previous failures of this enuinment due to the causes discussed have occurred. However, there hava been failures arising fron the related problen of the dry lubricant in the TIP tubo binding the ball valves and preventing their closure. The following is a list of these failures:

Date_ Unit Ball Valve Number 3-22-74 1 5 4-7-74 2 3 7-25-74 1 3 There are no safety implications for this abnormal occurrence due to the cumulativo experience since this is the first failure of this type experienced.

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