PNO-I-86-034, on 860424,plant Shut Down Due to Main Turbine Drain Line Steam Leak from Turbine Control Valve Header. Caused by Failed Weld at Socket Joint.Repairs Being Performed.Commonwealth of PA Notified

PNO-I-86-034:on 860424,plant Shut Down Due to Main Turbine Drain Line Steam Leak from Turbine Control Valve Header. Caused by Failed Weld at Socket Joint.Repairs Being Performed.Commonwealth of PA Notified

ML20203K945
Person / Time
Site:	Three Mile Island
Issue date:	04/24/1986
From:	Baunack W, Kister H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-86-034, PNO-I-86-34, NUDOCS 8605010090
Download: ML20203K945 (1)

r DCS No: 50289860424 Date: April 24, 1986 PRELIMINARY N0flFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-86-34 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region I staff on this date.

Facility: GPU Nuclear Corporation Licensee Emergency Classification:

Three Mile Island, Unit 1 Notification of Unusual Event DN 50-289 Alert Site Area Emergency

_ General Emergency

_X_ Not Applicable

Subject:

PLANT SHUTDOWN DUE TO MAIN TURBINE DRAIN LItlE LEAK About 11:25 a.m. on April 24, a steam leak was identified on a drain line from its associated main turbine control valve header. The leak appears to be a failed weld at a socket joint. Several failures had occurred on these lines in October 1985; but the lines had been modified since then.

In order to make repairs the licensee reduced power from 56*4 and took the turbine generator off the grid to isolate the steam supply to the drain line. Reactor power is being maintained at 5-10*;. The repairs are expected to take about 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to complete.

However, the generator may be kept off line longer for vendor evaluation of higher than normal vibration that had been noted on the generator exciter bearings.

This preliminary notification is issued for information only and the TMI-1 resident staff is following up onsite.

The Commonwealth of Pennsylvania has been notified.

CONTACT: Walter H. Baunack Harry B. Kister 488-1232 488-1233 DISTRIBUTION:

H. St. MNBB Phillips E/W Willste Mail: ADM:DM8 Chairman Palladino EDO flRR IE NMSS DOT:Trans only Comm. Zech PA OIA RES Comm. Bernthal ELD AE00 Comm. Roberts Comm. Asselstine ACRS A i r R i g h t s d:* 5 / *' INP0--y.. q- ,r^ -

SECY SP NSAC--- j r.n CA PDR Regional Offices _ TMI Resident Section 4 *e F m .

RI Re:,ident Office _ uf . , e. m .

Licensee:

(iie"adoTTicsses)'

Region I Form 83 (Rev. July, 1984) 0605010090 860424 PDR I&E PNO-I-86-034 PDR 16 c

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