ML053130108

Slides - Electrical Grid Problems Identified at Palo Verde

ML053130108
Person / Time
Site:	Palo Verde
Issue date:	11/02/2005
From:	Thomas Koshy NRC/NRR/ADES/DE
To:
References
FOIA/PA-2004-0307
Download: ML053130108 (4)

Text

Electrical Grid Problems Identified at Palo Verde Thomas Koshy, EEIB Division of Engineering (n

Office of Nuclear Reactor Regulation V..

o, X

. M.M CD 01

Purpose X Proposed by Richard Barrett, Director, DE X Information to understand grid vulnerabilities that could lead to loss of offsite power for long duration Success

• ET & LT understand the grid centered problems Not For Public Release 2

Agenda

• Description of the event

• Root cause

• Design Deficiency

• Impact on 500KV Grid

• Corrective Actions Not For Public Release 3

Event Description

• On June 14, 2004 at 7:44 a.m. all three Palo Verde Units tripped. One EDG for unit #2 failed to run

• Unit #2 went into an Alert because of one EDG and all offsite power unavailability

. All three units tripped from loss of load

• Electrical fault remained for 39sec.,

• Offsite power recovered by 8:18 a.m.

• 9:51 a.m. safety buses energized from offsite power for unit#2 Not For Public Release 4