Entergy's Waterford Plant In Trouble With Their Emergency Feedwater System.

Originally posted on 8/10...

Docket No. 50-382

July 30, 2015 SUBJECT: WATERFORD STEAM ELECTRIC STATION,UNIT 3 – NRC INTEGRATED INSPECTION REPORT 05000382/2015002

The Waterford Steam Electric Station, Unit 3, began the inspection period at 100 percent power. On April 17, 2015, the licensee lowered power to 70 percent due to a level switch failure on the low pressure feedwater heater 5C. Following repairs, the licensee raised power to 100 percent on April 20, 2015. On June 3, 2015, the control room operators manually tripped the reactor due to the automatic isolation of feedwater heater 2C and subsequent trip of main feedwater pump A. Following repairs to the feedwater heater 2C normal level control valve, the licensee restarted the reactor on June 6, 2015, and achieved 100 percent power on June 8, 2015. The licensee shutdown the reactor on June 23, 2015, to address a steam leak on an isolation valve that was downstream of a main feedwater regulating valve. The licensee restarted the reactor on June 24, 2015, and achieved 100 percent power on June 25, 2015. The unit maintained 100 percent power for the remainder of the inspection period.

Why does Entergy's Louisiana nuclear plants have so many issues with emergency and normal reactor cooling feedwater feed? Why all the problems with feed water pump trips.     

Loss of Feed water pump...I called it sabotage?  

I can't begin to tell you how bad this is. It indicates the plant is effectively out of control. A component failure occurs, then a important safety system such as the emergency feed water system is found to be broken. It is really bad when two components show up broken in the same plant event.

So there were never any pre operational testing of the emergency feedwater system...this system had been inop from first start-up.

I think 10% to 15% of domestic nuclear industry fleet capacity factor is illegitimate. We would have between 10% to 15% less capacity if the licensees were forced to follow all the rules and tell the truth. There is widespread blatant dishonesty and blatant rules violations that supports up to 15% of our domestic nuclear plant average fleets capacity factor. This is a tremendous amount of money.   

Licensee Event Report (LER) 2015-004-00, Emergency Feedwater System Flow Oscillations and LER 2015-005-00, Manual Reactor Trip due to Low Steam Generator Levels Waterford Steam Electric Station, Unit 3 (Waterford 3)

The safety function of the EFW system is to provide sufficient supply of cooling water to one or both SGs for the removal of decay heat from the Reactor Coolant System (RCS) [AB] in response to any event causing low SG level coincident with the absence of a low pressure trip.

On June 3, 2015, at 1707, following a manual reactor scram [RCT] from 100% power, an Emergency Feedwater Actuation Signal (EFAS) [JE] was automatically actuated to both Steam Generators (SGs). Following flow initiation, the Emergency Feedwater (EFW) [BA] Backup Flow Control Valves (BFCVs) [FCV] for both trains exhibited wide, frequent oscillations. The Primary Flow Control Valves (PFCVs) [FCV] operated correctly in automatic. To prevent further oscillations, operators took manual control of both trains of EFW in accordance with station procedures and stabilized flow. Both channels of EFAS flow control logic [JB] and both trains of EFW BFCVs were subsequently declared INOPERABLE and Technical Specifications (TSs) 3.3.2.b and 3.7.1.2.d were entered, respectively. The EFW system functioned adequately to fill the SGs and maintain the specified safety function (Reactor Coolant System Heat Removal).

The air operated EFW valves are provided with nitrogen backup from dedicated accumulators [ACC] which are only used during a loss of the instrument air (IA) system [LD]. These nitrogen accumulators also supply backup nitrogen to the Atmospheric Dump Valves (ADVs) [V]. Follow up analysis has determined that the identified valve cycling would have exceeded the assumed nitrogen consumption rate and, without operator intervention, would have exhausted the accumulators prior to the credited 10 hour analyzed mission time. The specified safety functions of both trains of EFW and both ADVs would not have been fulfilled.

Investigation into this event revealed that the components comprising the EFW flow control system were not configured to appropriately respond to the changes observed in the system operating parameters and that periodic testing to confirm the stability of the BFCVs in the automatic flow control mode had not been performed. It is therefore reasonable to assume that this condition has likely existed within 3 years of the time of discovery.

Compensatory measures have been put in place to station a dedicated operator to control the EFW BFCVs in manual following a reactor trip to establish and maintain the SG level in accordance with emergency operating procedures. This action will protect the associated nitrogen accumulators from depletion due to the excessive cycling of the BFCVs during an EFW actuation. Crediting the established compensatory measures, the EFW and ADVs are capable of performing their specified safety functions for the evaluated mission times.

The air operated EFW valves are provided with nitrogen backup from dedicated accumulators [ACC] which are only used during a loss of the instrument air (IA) system [LD]. These nitrogen accumulators also supply backup nitrogen to the Atmospheric Dump Valves (ADVs) [V]. Follow up analysis has determined that the identified valve cycling would have exceeded the assumed nitrogen consumption rate and, without operator intervention, would have exhausted the accumulators prior to the credited 10 hour analyzed mission time.

One contributing cause of this event was that there is no periodic testing that confirms the stability of the BFCVs in the automatic flow control mode. No startup test exists where the system was allowed to shift the BFCVs to the flow control mode and control in this mode.