U1 Main Turbine Cooling/SS/LO Flashcards
What are the U1 MT Trips?
Hardwire Trips
- Reactor Trip
- AMSAC (activated at > 40% pwr, auctates at < 25% FW flow 3/4)
- SI
- Overall HEA
- Unit HEA
- IOPS 110%
- Loss of SCW (10 second delay)
- Low Pressure 13 #
- Low Flow 195 gpm
- High Temp 95°C (+ 5 second delay) - Thrust Bearing Wear Abnormal > 39 mils (axial)
- Manual
- P14 (SG Hi Hi Lvl at 67% 2/3 on 1 SG)
PLC Trips
- Low EHC # 1100#
- EHC 2/3 < 800#
- Overspeed 107%
- Low Bearing Oil # < 8# for 5 sec ***
- Low Condenser Vacuum ≤ 24.1” Hg OR 30 minutes < low setpoint (variable)
- Loss of both DCS Pwr supplies
What auto starts a AC Suction LO Pump on U1?
- Low Suction Press < 10# from the Shaft Driven Oil Pump
- Turbine Trip
What auto starts a DC Emergency Bearing Oil Pump on U1?
- Low discharge press < 125# from the Shaft Driven Oil Pump WITH Turning Gear oil pp discharge press < 10# ***
- Turbine Trip
What auto starts the Turning Gear Oil pump and the DC Backup Oil Pump?
- Bearing Header pressure < 15#
- Turbine Trip
When do the Bearing Lift Pumps auto start?
- Auto start on Turbine Low Speed Switch only (Does NOT start on turbine trip)
When do Bearing Lift Pumps 2 and 4 start?
- Start 20 seconds after Turning Gear engagement to ensure sufficient drag on turbine shaft to prevent the Turning Gear from disengaging
What are the Bearing Lift Pumps interlocks?
- Interlocked to have Lift Pump suction pressure of > 8# to start Lift Pump
When do lift pumps stop?
- Lift Pumps stop when suction pressure < 2#.
Which stop valve allows pre-heating of chest and shell (HPT)?
- # 2 Stop Valve
When does the U1 Turning Gear auto engage?
- When the turbine tops (< 1/2 rpm)
What are the U1 Turning Gear interlocks?
Will start if:
- 1 oil pump on (Turn Gear Oil, Backup Oil, Emerg Oil)
- Bearing oil # > 25#
- Lift pump disch # > 440# (Except pumps 2 & 4)
- Bypass buttons available
for lift pumps and #2 Stop Valve interlocks
- Main Turbine stop valves closed
What is the turning gears purpose?
- Prevents/removes turbine bow on the shaft
- Removes a temporary rotor bow during turbine warm up, before a turbine roll
At what speed does IOPS start sensing speed of the turbine?
- 100 rpm
What are the Main Turbine Vib alarms?
- high at 8 mils
- High High at 14 mils (Bearings 3-8) and 12 mils (bearings 1, 2, 9-12)
- Manual Trip required on Turbine Vib High High
What does the Thrust Bearing maintain and support?
- Limits axial movement of the turbine rotor to prevent stationary and rotating blade contact
What does the Journal Bearing maintain and support?
- Support the weight of the turbine and generator rotors and restrict movement to axial direction only
What do the Combined Stop/Intercept valves do?
- Control flow of steam from MSRs to 3 LPTs
- Close on turbine trip to avoid overspeed due to steam in MSRs***
Which turbines have a rupture disc and when does it rupture?
- LPTs contain rupture discs that release if pressure exceeds 5#
What does 33VED (Turbine Trip) provide?
- Generator Motoring Alarm
- Starts Motor Suction Oil Pump
- DC Emergency Lube Oil Pump
- DC Backup Oil Pump
- Actuation of Overall Differential HEA
What does Overall Differential HEA actuate?
- Open Generator Output Breakers
- Opens Generator Field Breakers
- Fast Bus Transfer to RAT
- Enables Main Transformer Fire Deluge Valve
What are Main Turbine Steam seals supplied by during startup, shutdown, and low load operation?
- 50# Aux Steam (SRV-10 and SMO-10) (Maintains steam seals at 4#
What are Main Turbine Steam seals supplied by during normal operation?
- leakage from exhaust of HPT and MFPTs supply steam to LPTs and MFPT exhaust end seals, SRV-11 ctrls at 4#
Where does SRV-11 dump to?
- 1 A/B heaters
How does SRV-10 Fail(Aux Steam supply to Steam Seals)?
- Fails Open
How does SRV-11 Fail (Steam Seal Dump Valve?
- Fails closed
What are the EHC pump auto starts?
Auto 1 - 1450# - if run pump goes to status other than run or test - 3/3 EHC transmitters fail - Auto 1 Test Signal Auto 2 - 1375# - Auto 1 Test Signal
What will trip an EHC heater?
- Low Low EHC tank Lvl
What does SRA-1800 look for on U1?
- Primary to secondary tube leak
What will isolated on a Extreme High Lvl in the Gland Steam Condenser?
- CMO-630 (TACW supply valve) will isolate
What maintains the bearing oil header pressure for the U1 Main Turbine?
- 1-SV-248 maintains it at 25#
What are the EHC loads?
- Main Feed Pumps
- Main Stop Valves
- Front Standard
- Main Control Valves
- Right Intermediate Valves
- Left Intermediate Valves
If starting up, what is supplying steam seals and how are srv-10 and svr-11?
- SRV-10 is throttled open and SRV-11 is closed
