Reactor Feedwater - 1.0

Question 1

What are the steam supply paths to the RFP Turbine?

Answer 1

1) When the Main Turbine is on-line, LP steam from the cross-around header provides the motive force for RFPT operation.
2) When the Main Turbine is not on-line, HP steam from upstream of the Main Turbine Stop Valves provides the motive force for RFPT operation.

Question 2

Are all steam paths available to the RFT Turbine when the MT is on the grid?

Answer 2

If the Main Turbine is not online and synced to the grid, you do not have low pressure steam available to the feedpumps.

Question 3

How does the RFP controller operate when in Manual?

Answer 3

RFPT in manual controls turbine speed demand only. Manual mode will attempt to automatically control turbine speed by adjusting the control valve position.

Question 4

What are the interlocks associated with the Feed pump suction valve?

Answer 4

To open the HV-1781 the following must be shut:
HV-1769 Discharge valve
FV-1783 Min Flow valve

Question 5

What are the interlocks/automatic actions associated with the RFP oil pumps?

Answer 5

• Main and Aux Oil Pump will auto start when in AUTO
  AND
  Bearing pressure (8-10psig)
  OR
  Control Oil pressure (100psig)
• RFP Emergency Oil Pump Starts: Lube oil pressure 6-8psig

Question 6

What are the RFP Turbine Trips?

Answer 6

• Manual PB (10C651, By Turbine, Turbine control panels)
• Low-Low Lube Oil Pressure (5psig / 3sec) [2/3]
• Low suction pressure (230psig / 10sec) [2/3]
• Low Condenser Vacuum (10”HgA) [2/3]
• Low flow and speed >5400rpm
• Low Control Oil Pressure (60 psig) [2/3]
• Hi-Hi RFP discharge pressure (1700psig) [2/3]
• Hi Rx Level (+54”) [2/3]
• Hi Exhaust Pressure (2psig) [2/3]
• Hi Exhaust Temperature (230F) [2/3]
• Power Failure to the trip system
• Loss of both speed sensing signals to overspeed trip
• Overspeed (>6100rpm)
• Thrust Bearing Wear Detector (danger)
• RFPT Speed <100rpm >60 sec after opening control vlvs
• Suction valve not full open
• Mositure Removal Drain valve not full open (1765)

** Steam Header drains auto open on RFPT trip
And HP & LP Stop and CVs close

Question 7

What are the RFPT Turning Gear Interlocks?

Answer 7

• Moisure removal drain full open
• 1st stage drain full open
• RFPT high pressure stop vlvs closed
• RFPT low pressure stop vlvs closed
• Lube Oil Pressure normal
• Zero speed relay satisfied
• RFPT is tripped

Question 8

What is the key information regarding the RFP runbacks caused by the PCPs and SCPs?

Answer 8

RFP Runback SCP (PCP) Trip SCP – 89.3% (PCP – 86.3%)
* Total FW Flow > 73.65%
* 2 or 3 RFPT’s on line
* All 3 Secondary (Primary) Condensate Pumps Running
* One Secondary (Primary) Condensate Pump Trips

Question 9

What occurs during an RRCS RFP runback?

Answer 9

RRCS Runback Runback to minimum speed (2500RPM) – if there is a digital speed control failure, it falls to the woodward minimum speed of 650rpm

Question 10

What provides RFP Shaft Seal Water?

Answer 10

SCP discharge. Prevents leakage, cools, and lubricates.

Question 11

At what setpoint does the RFP rupture diaphragm rupture?

Answer 11

5 PSIG

Question 12

What are the key operations associated with the RFP min flow valve?

Answer 12

1. Fails open on a loss of air (water directed to condenser)
2. Nominally set to maintain 3500gpm.
3. Min flow isolation valve (1797) must be full open to reset RFPT
   * Main or Aux Lube oil pump must be running to open.

Question 13

How do you control feed on a loss of digital control?(fancy soft button)

Answer 13

On loss of digital control you have a subsequent xfer to manual, use the bezel buttons for RFPs (that we never use) to directly control RFP governor speed.

1. The normal digital softkey buttons are called “TURB CONTROL INC SPEED DEC SPEED” pushbuttons
2. The RFPT mechanical governer bezel backup push button is called “REACTOR FEEDPUMP A(B, C) SPEED CONTROLER DMND INC OR DEC” pushbutton

Question 14

What causes the RFP trip at 1.68#?

Answer 14

Feed pumps trip on load shed of the bearing oil system