LP Feedwater Heater Tube Failure Point Beach Nuclear

LP Feedwater Heater Tube Failure Point Beach Nuclear Plant Kelly Oetting System Engineer FSRUG 2015 Conference January 26 -29, 2015

2011 Power Uprate • Westinghouse 2 – Loop PWR, Unit 1 1970, Unit 2 1972 • 17% • 545 MWe to 637 MWe (1540 MWth to 1800 MWth) • Unit 2 – 120 Days (3/1/11 - 6/19/11) • Unit 1 – 75 Days (10/3/11 – 12/17/11) • Approximately 35 Major Modifications for Each Unit • New FWHs 5 Stages, Two Trains (4 LP & 1 HP FWH/Train) 2

New #1 & #2 Duplex LP FWH 3

FWH Design Change Details Before EPU After EPU Westinghouse (shell) Southwest Eng. (tube bundle) Yuba 41 ft 9 in 49 ft 68 in 79. 25 in Heat Transfer #1 147, 500, 000 Btu/hr 141, 100, 000 Btu/hr Heat Transfer #2 116, 700, 000 Btu/hr 126, 600, 000 Btu/hr #1 & #2 LP FWHs Length Diameter 4

#2 FWH Tube Failures April 2014 - #1&#2 Drain valves started opening more May 2014 - #1&#2 Dump Valve started to open Step change down in #2 drain temperature Monitored until October 2014 Refueling outage Found 6 tubes leaking in #2 FWH 2 tubes sheared off Stabilizers installed in 14 tubes 16 tubes plugged 5

6

7

Motor Bearing Housing Sightglass 8

Potential Causes 1. Water level too low – knee test never performed 2. Drain piping and/or drain valve sized too small 9

Actions Raised level in all #1, #2, and #3 FWHs Will be pursuing a study of the drain piping. 10