Junk Plant Watts Bar 2: Simulator Training and Fidility Sucks?

These are the guys with safety culture problems and the NRC is concerned TVA employees are talking to me.

Licensee Event Report 391/2016-005-00, Main Feedwater Pump Trip on Loss of Condenser Vacuum Leads to Turbine Trip and Reactor Trip

On June 20,2016, the 28 Main Feedwater Pump (MFP) {EllS:P} kipped on a loss of vacuum in the 28 MFP turbine condenser, resulting in a loss of normalfeed {El|S:SJ}, and the subsequent trip of the main turbine. While operators were reducing power to within the capacity of Auxiliary

Feedwater (AFW) {EllS:BA} , the reactor tripped at 1540 Eastern Daylight Time (EDT) on Steam Generator Water Level (SGWL) Lo Lo in Steam Generator No.4. SG water level lowered rapidly due to shrink from the relatively cold AFW following the trip.

The cause(s) and circumstances for each human performance related root cause. 

Operations staff did not recognlze that, based on the system alignment present shown in Figure 1, that lowering the 2A MFPT condenser below a certain point would cause a loss of vacuum on the 28 MFPT condenser. Additionally, when taking manual control of steam generator water level, the TTDs for steam generator level were already actuated, and operators should have manually tripped the reactor prior to reaching an automatic trip. The MFPT Condensers for the 2A and 28 MFPs share a common MFPT Condenser Drain Tank. When AUOs drained the 2A MFPT Condenser completely, an air in leakage path was created from the turbine steam seals on the 2A MFPT (steam seals were out of service) through the 2A MFPT Condenser to the MFPT Condenser Drain Tank to the 28 MFPT condenser (see Figure 1). This resulted in a loss of vacuum on the 28 MFPT Condenser and a trip of the 28 MFPT.

Loss of the 28 MFP led to a main turbine trip. Operations attempted to reduce power such that the AFW system could maintain SG level, but were unsuccessful.