ML20084S028

AO 50-249/74-25:on 740807,ball Isolation Valve on Transversing in-core Probe Machine B Failed to Close.Caused by Broken Wire on Solenoid Coil Actuator.Top Actuator of Valve Replaced

ML20084S028
Person / Time
Site:	Dresden
Issue date:	08/19/1974
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084S030	List: ML20084S028 ML20084S043
References
597-74, AO-50-249-74-25, NUDOCS 8306160114
Download: ML20084S028 (3)

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C:tnnharelth Edison One First twenal Piaza. Ch::ago, in nom

/. . Address Reply to: Post Othee Box 7G7 Chicago, ll!inois 60690 BBS Ltr.#597-74 Dresden Nuclear Pcwer Station R. R. #1 -m Morris, Illinois 6045R(*.a-@g 0

50-249 August 19, 1974 g

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Mr. James G. Keppler, Regional Director ,, 14 MC'7, !Cl d Directorate of Regulatory Operations-Region III U. S. Atomic Enargy Co::xnission hh[ <hY:

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799 Roosevcit Road a '6 Glen Ellyn, Illinois 60137 SUBJECI: _ REPORT OF ABNORMAL OCCURRENCE PER SECTION 6.6.B OF '1V2 TECHNICAL SPECIFICATIONS.

TIP MACHINE EALL VALVE FAILURE TO CLOSE.

References:

1) Regulatory Guide 1.16 Rev.1 Appendix A -

2) Notification of Region III of AEC Regulatory Operations Telephone: F. Maura,1415 hourc on August 8,1974 Telegram: J. Keppler, 1447 hours0.0167 days <br />0.402 hours <br />0.00239 weeks <br />5.505835e-4 months <br /> on August 8,1974 Report Number: 50-249/1974-25 Report Date: August 19, 1974 Occurrence Date: August 7, 1974 Facility: Dresden Nuclear Power Station, Morris, Illinois IDEffrIFICATION OF OCCURRENCE The ball isolation valve on the Unit 3 "B" transversing incere proba (TIP) machine failed to close as is nor=al following the retraction of the 3B TIP probe into its shield.

CONDITIONS PRIOR TO CCCURRENCE

, The ball valve had been actuated open for the purpose of taking l dcta with the TIP system approximately three hours prior to the observed failure. During these three hours, the valve remained open. No abnormal operation of the 3B TIP machine was noted during the data taking.

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Mr. James G. Kappist August 19, 1974

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DESCRIPTION OF OCCURRENCE ,

Data from the Unit 3 TIP system was taken from approximately 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br /> until 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br /> on August 7,1974. To begin the data taking, all TIP probes were driven out of their shields, and all isolation ball valves were actuated open. Data taking proceeded normally, with no TIP machine malfunctions noted, save a position tracing probica on two traces, which was attributed to dirty contacts.

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The ball valve malfunction was noted at the TIP machine operating

panel by means of an indication light, which illuminates when the ball valve is in the open position. The valve normally closes when the TIP probe is retracted into its shield, or can be manually actuated to close. Neither method was observed to work, and the ball valve was considered failed at 1910 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.26755e-4 months <br /> on August 7,1974.

Following the observed malfunction, a safety related work request

(#7114) was issued at urgent priority. The 3B TIP machine was placed out of service, and while workers were in the TIP machine room, the entire TIP system ,

for Unit 3 was placed out of service.

l Repairs to the 3B TIP machine ball isolation valve were completed on August 9, 1974, and the TIP system was returned to service.

Subsequent operation of the TIP machines proceeded normally.

APPARENT CAUSE OF OCCURRENCE (Component Failure)

Examination of the failed ball valve identified c broken wire on the solenoid coil actuator as the cause of the failure.

I ANALYSIS OF OCCURRENCE The isolation ball valve is part of the p'rimary containment, in series with the isolation shear valve. The latter actuates under emergency isolation conditions, and was checked and found operable at the time of the repair. Thus, emergency primary containment was not compromised by the ball valve failure, and no threat to plant or public health and safety existed.

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The occurrence is directly attributed to the malfunction of the 3B TIP machine ball isolation valve and to no other cause.

CORRECTIVE ACTION Repairs done to the 3B TIP machine ball isolation valve fnvolved replacement of the top actuator portion of the valva with a new unit.

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e Mr. James G. Kepplar o O August 19, 1974 l

. 1 FAILURE DATA On June 19,1974, 3B TIP machine ball isolation valve failed to close, but was inspected and found closed and successfully cycled subsequent to the apparent failure. See deviation report no. D12-3-74-33, " Unit 3 TIP Ball Valve Apparent Failure".

EQUIPMENT IDENTIFICATION 580A56 Valve, Nuclear Instrumentation, General Electric Company NID. ~

1. 112C2391P001, Ball, Eor Transversing In-Core Probe.

Sincerely,

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B,/B. S_tephenson -

Superintendent BBS:JGT:do O

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