ML110190647

Document Report, Subject: Failure Mechanism of 21 Main Transformer, and Extent of Condition IP

ML110190647
Person / Time
Site:	Indian Point
Issue date:	11/07/2010
From:	NRC Region 1
To:
References
FOIA/PA-2011-0045, FOIA/PA-2011-0066
Download: ML110190647 (4)

Text

Failure Mechanism of 21 Main Transformer and Extent of Condition CR: IP2-2010-6801 CA: 15 Summary:

Outside of Scope

,*Atl18:39 on 11/-7l/l10,"with !the plant at approximately

100%

ona-2lTVMain 'Transformeriwhich-resultedjn, a Unit :power, afault o-6ccurred°n

.Aler wasideclared, in acc rdance.With-EAL,8.2.:3;,,d 2 autbmatic-trip,.,An ue to:the subsequent 21 Main Trarsfotmer explosion.

Outside of Scope t4 ~)

-~

L I The'transformer' experienceda rapid increase in pressure due

'B'.phase high voltage bushing. Thisý sudden to the-failure-of the.

increase caused the tank to fail.

,Combustible gases, from arcing, built up in theitransformer leaked. from-the tank~breach After several rmore6 aszthe insulating oil minutes, enough oxygen

,combined .,with the hot gasescausing.a secondary.,explosion!

forphotos' of damage to bushings and ruptured See Attachment 3 transformer tank.

Outside of Scope

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Outside of Scope (23 Pages)

Outside of Scope (42 Pages)