U1 Main Turbine Cooling/SS/LO

Question 1

What are the U1 MT Trips?

Answer 1

DCS:

• Condenser Vacuum ≤ 24.1” Hg OR 30 minutes < low setpoint (variable)
• Overspeed 107%
• Oil # (Bearing) < 8# for 5 sec ***
• Low EHC # 1100#
• Low trip header pressure 2/3 < 800#

Hardwire Trips:

• AMSAC (activated at > 40% pwr, auctates at < 25% FW flow 3/4)
• SI
• SG Hi Hi Lvl at 67% 2/3 on 1 SG (P14)
• Manual
• Overall HEA
• IOPS 110%
• Stator Water (10 second delay)
  - Low Pressure 36 #
  - Low Flow 499 gpm
  - High Temp 81°C (+ 5 second delay)
• Thrust Bearing Wear Abnormal > 39 mils (axial)
• Unit HEA
• Reactor Trip
• Emergency Trip

Question 2

What auto starts a AC Suction LO Pump on U1?

Answer 2

• Low Suction Press < 10# from the Shaft Driven Oil Pump

- Turbine Trip

Question 3

What auto starts a DC Emergency Bearing Oil Pump on U1?

Answer 3

• Low discharge press < 125# from the Shaft Driven Oil Pump WITH Turning Gear oil pp discharge press < 10# ***
• Turbine Trip

Question 4

What auto starts the Turning Gear Oil pump and the DC Backup Oil Pump?

Answer 4

• Bearing Header pressure < 15#

- Turbine Trip

Question 5

When do the Bearing Lift Pumps auto start?

Answer 5

• Auto start on Turbine Low Speed Switch only (Does NOT start on turbine trip)

Question 6

When do Bearing Lift Pumps 2 and 4 start?

Answer 6

• Start 20 seconds after Turning Gear engagement to ensure sufficient drag on turbine shaft to prevent the Turning Gear from disengaging

Question 7

What are the Bearing Lift Pumps interlocks?

Answer 7

• Interlocked to have Lift Pump suction pressure of > 8# to start Lift Pump

Question 8

When do lift pumps stop?

Answer 8

• Lift Pumps stop when suction pressure < 2#.

Question 9

Which stop valve allows pre-heating of chest and shell (HPT)?

Answer 9

• # 2 Stop Valve

Question 10

When does the U1 Turning Gear auto engage?

Answer 10

• When the turbine stops (< 1/2 rpm)

Question 11

What are the U1 Turning Gear interlocks?

Answer 11

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)
- Any lift pump not operation (except 2 and 4)
- Bypass buttons available
for lift pumps and #2 Stop Valve interlocks

Question 12

What does the Thrust Bearing maintain and support?

Answer 12

• Limits axial movement of the turbine rotor to prevent stationary and rotating blade contact

Question 13

What do the Combined Stop/Intercept valves do?

Answer 13

• Control flow of steam from MSRs to 3 LPTs

- Close on turbine trip to avoid overspeed due to steam in MSRs***

Question 14

What are Main Turbine Steam seals supplied by during startup, shutdown, and low load operation?

Answer 14

• 50# Aux Steam (SRV-10 and SMO-10) (Maintains steam seals at 4#

Question 15

What are Main Turbine Steam seals supplied by during normal operation?

Answer 15

• Leakage from exhause ends of HP & MFP turbines AND stem leak-off

Question 16

Where does SRV-11 dump to?

Answer 16

• 1 A/B heaters

Question 17

How does SRV-10 Fail(Aux Steam supply to Steam Seals)?

Answer 17

• Fails Open

Question 18

How does SRV-11 Fail (Steam Seal Dump Valve?

Answer 18

• Fails closed

Question 19

What are the EHC pump auto starts?

Answer 19

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

Question 20

What will trip an EHC heater?

Answer 20

• Low Low EHC tank Lvl

Question 21

What will isolated on a Extreme High Lvl in the Gland Steam Condenser?

Answer 21

• CMO-630 (TACW supply valve) will isolate