SUBJECT: SHUTDOWN DUE TO CONDENSER FAILURE
On March 23, 2017, at 12:14 a.m., Watts Bar Unit 2 was operating at 16 percent power when
the B waterbox of the main condenser experienced a structural failure causing the loss of the
running main feedwater pump and an automatic turbine trip. All Auxiliary Feedwater Pumps
(AFW) started as expected and operators manually inserted control rods to lower reactor power
to about 3 percent as directed by plant procedures. Subsequently, the operators shut all Main
Steam Isolation Valves (MSIVs) due to steam in the turbine building from the damaged B
condenser waterbox. Upon closure of the MSIVs, heat removal was maintained through the
steam generator power operated relief valves. The reactor was later shut down as part of a
planned evolution. Watts Bar Unit 2 is currently stable in Mode 3.
This preliminary notification is issued for information only and no specific reactive inspection by
the staff is anticipated. Region II received initial notification of this occurrence by telephone from
the senior resident inspector at 1:07 a.m. on March 23. Subsequently, at 2:48 a.m., the
Tennessee Valley Authority (TVA) issued an 8-hour Event Notification (EN) 52630 due to the
automatic start of the AFW pumps in response to the main feedwater pump trip. The
information presented herein has been discussed with TVA and the State of Tennessee, and is
current as of 1:00 p.m., March 23.
People I know say the hole is large enough for 3 people to walk through at once. Hearsay is rampant but I've heard 3 6 and 8 months to fix.