Headquarters Daily Report
DECEMBER 28, 2001
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REPORT NEGATIVE NO INPUT
ATTACHED INPUT RECEIVED RECEIVED
HEADQUARTERS X
REGION I X
REGION II X
REGION III X
REGION IV X
PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION II DEC. 28, 2001
Licensee/Facility: Notification:
Southern Nuclear Operating Company MR Number: 2-01-0020
Hatch 1 2 Date: 12/28/01
Baxley,Georgia
Dockets: 50-321,50-366
BWR/GE-4,BWR/GE-4
Subject: UNIT 2 REACTOR SCRAM
Discussion:
Reference Event Number: 38592
On December 25, 2001, Unit 2 automatically scrammed due to high neutron
flux. The licensee initially attributed the cause of the scram to a
speed increase of the 2A Reactor Recirculation Pump.
On December 26, 2001, after reviewing additional data the licensee
determined that a rapid steam flow reduction in the 'B' steam line
resulted in a Reactor Pressure Vessel pressure increase. The licensee
conducted testing of the 'B' steam line and determined that the Outboard
Main Steam Isolation Valve disc had separated from the stem. The
resulting pressure increase due to the MSIV failure cause in a positive
reactivity insertion due to void collapse causing the reactor to scram.
The licensee is in the process of evaluating the cause of the stem
failure and has planned a 94 hour forced outage to repair the valve.
Regional Action:
None.
Contact: Curt Rapp (404)562-4674
Joel Munday (912)367-9881
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