PNO-III-88-067, on 880722,controlled Shutdown Initiated to Repair Steam Leak.Unit Down for More than 48 H for Steam Leak Repair & Portions of Piping Which Exhibited Wall Thickness of Less than Three Inches.State of Il Notified

PNO-III-88-067:on 880722,controlled Shutdown Initiated to Repair Steam Leak.Unit Down for More than 48 H for Steam Leak Repair & Portions of Piping Which Exhibited Wall Thickness of Less than Three Inches.State of Il Notified

ML20151K420
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	07/25/1988
From:	Forney W, Hinds J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-88-067, PNO-III-88-67, NUDOCS 8808030180
Download: ML20151K420 (1)

I PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-88-67 Date July 25, 1988 (AO is preliminary notification constitutes EARLY notice of events of POSSIBLE safety

'public interest significance. The information is as initially received without erification or evaluation, and is basically all that is known by the Region III staff on this date.

Facility: Commonwealth Edison Company Licensee Emergency Classification:

Zion Unit 1 Notification of an Unusual Event Zion, IL 60099 Alert Site Area Emergency D'acket No. 50-295 General Emeriency [l X Not Applicalle

Subject:

SHUTDOWN TO REPAIR STEAM LEAK At 11:22 a.m. (CDT), July '22, 1988, with the unit at 98 percent power, a steam leak was identified in the vicinity of the extraction steam piping between the high pressure turbine and a bank of feedwater heaters.

The licensee decreased power to 40 percent and removed piping insulation to locate the leak. The licensee subsequently initiated a centrolled shutdown (the unit tripped at 10 percent power) and conducted an ultrasonic inspection of the 16-inch diameter piping.

Preliminary results indicate the pipe wall thickness in the vicinity of the leak had been reduced to .087 inches from the 0.5-inch nominal wall thickness. Additional examination revealed pipe wall degradation at other locations on the extraction steam piping. .

The unit will be down for more than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> while the licensee repairs the steam leak and those portions of the piping which exhibit a wall thickness of less than 0.3 inches.

Region III (Chicago) is following the licensee's course of action.

The State of Illinois will be notified.

Region III was notified of this event at about 3 p.m. (CDT), July 22, 1988. This information is current as of 3:30 p.m. (CDT), July 25, 1988.

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.'b N CONTACT- J Hinds W. Forney b 1TS 388-5575 FTS 388-559 W' S

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SECY OGC Resident Inspector D0T (Trans. Only)

OGC-H FAX T0: Nicholson Lane Regions CA INPO 4'.61 RES Region I GPA NSAC q 30 Region II ACRS Licensee a4 .% Region IV PDR HQS. Operations Officer 4 1 6 Region V Region III Rev. June 1988