Wednesday, July 26, 2017

New Plant Watts Bar 2 Tried To Restart from Collapsed Condenser, Then New Scram  

This is a very troubled site. Systemic NRC safety culture problems, poor quality equipment and severe capacity factor problems.
Facility: WATTS BAR
Region: 2 State: TN
Unit: [ ] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BRIAN MCLINAY
HQ OPS Officer: VINCE KLCO
Notification Date: 07/25/2017
Notification Time: 11:07 [ET]
Event Date: 07/25/2017
Event Time: 04:28 [EDT]
Last Update Date: 07/25/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
ALAN BLAMEY (R2DO)

UnitSCRAM CodeRX CRITInitial PWRInitial RX ModeCurrent PWRCurrent RX Mode
2M/RN0Hot Standby0Hot Standby
Event Text
MANUAL REACTOR TRIP DUE TO ROD POSITION INDICATION SYSTEM BEING INOPERABLE

"On July 25, 2017, at 0428 Eastern Daylight Time (EDT) Watts Bar Nuclear Plant (WBN) Unit 2 was in Mode 3, beginning a Reactor Startup. While in the initial phase of withdrawing the first of four Control Rod banks, the two associated group demand position indicators deviated greater than 2 steps from each other. In accordance with Technical Requirement 3.1.7, Position Indication System, Shutdown, with one or more group demand position indicators inoperable, the reactor trip breakers are to be opened immediately. Operations personnel opened the reactor trip breakers immediately by initiating a manual trip of the Reactor Protection System (RPS). The Auxiliary Feedwater system was in service and controlling Steam Generator water levels at the time of the event and did not receive any valid actuation signals. No other system actuations occurred as a result of this reactor trip and all systems operated as designed.

"The cause of the position indication system inoperability is currently under investigation.

"NRC Resident Inspector has been notified."

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