PNO-II-86-061, on 860827,turbine & Reactor Manually Tripped Due to High Bearing Vibration on Main Turbine.Caused by Damage to Some Turbine Blades on Last Stage of Low Pressure Turbine.Corrective Action Being Evaluated

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PNO-II-86-061:on 860827,turbine & Reactor Manually Tripped Due to High Bearing Vibration on Main Turbine.Caused by Damage to Some Turbine Blades on Last Stage of Low Pressure Turbine.Corrective Action Being Evaluated
ML20214P542
Person / Time
Site: North Anna Dominion icon.png
Issue date: 08/29/1986
From: Brownlee V, Croteau R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-86-061, PNO-II-86-61, NUDOCS 8609230231
Download: ML20214P542 (1)


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August 29, 1986 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-86-61 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region II staff on this date.

FACILITY: Virginia Electric & Power Company Licensee Emergency Classification:

North Anna Unit 1 X Notification of Unusual Event Docket No. 50-338 Alert Mineral, Virginia Site Area Emergency General Emergency Not Applicable

SUBJECT:

DAMAGE TO LOW PRESSURE TURBINE BLADES Plant operators manually tripped the turbine and reactor of North Anna Unit 1 at 10:41 a.m.

(EDT) August 27 after high bearing vibration developed on the main turbine while the unit was operating at 100 percent power. An unusual event was declared, in accordance with the site emergency plan, but was terminated at 11:40 a.m. after the reactor was in hot standby and the turbine was on the jacking gear.

A preliminary inspection yesterday disclosed damage to some turbine blades on the last stage of one of the low-pressure turbines. The unit will be cooled down and placed on the residual heat removal system while Virginia Power and representatives of Westinghouse d:velop a course of action for evaluating and repairing the damage. North Anna Unit 2 is op2 rating at 100 percent power.

Virginia Power is prepared to respond to media inquiries.

Tha Commonwealth of Virginia has been informed.

Virginia Power informed the NRC headquarters duty officer of.this occurrence by telephone at 11:32 a.m. August 27. This information is current as of 8 a.m. today. ,

Contact:

R. Croteau, 242-4468 V. L. Brownlee, 242-5583 DISTRIBUTION:

H. Street MNBB Phillips Efj{ Willste MAIL:

Chairman Zech Ei6- NRR IE NMSS ADM:DMB Comm. Roberts PA OIA RES DOT: Trans Only Comm. Asselstine MPA AE0D Applicable State Comm. Bernthal ELD r Air Rights INP0 - +

SECY SP NSAC Regions:

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M' Licensee: h a!Tt[

(Reactor Licensees)

Applicable Resident Site 3 ,g 7 h

8609230231 860829 M-I!-86-061 PDR oh a-f34