U1 Main Turbine Cooling/SS/LO

Question 1

What are the U1 MT Hardwired Trips?

Answer 1

AMSAC
SI
Steam generator Level Hi-Hi 67%
Manual
Overall HEA
IOPS 110%
Stator Cooling Water (10 sec delay)
- Lo Press
- Lo Flow
- Hi Temp
Thrust Bearing position Abnormal ±39 mils
Unit HEA
Reactor Trip
Emergency Trip

Question 2

What auto starts an AC Suction LO Pump on U1?

Answer 2

• Turbine Trip
• 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

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

Question 4

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

Answer 4

-Turbine Trip
- Bearing Header pressure < 15 psig

- Turbine Trip

Question 5

When do the Bearing Lift Pumps auto start?

Answer 5

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

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

Question 7

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

Answer 7

2 Stop Valve

Question 8

When does the U1 Turning Gear auto engage?

Answer 8

When the turbine stops (< 1/2 rpm)

Question 9

What is the turning gears purpose?

Answer 9

Prevents/removes turbine bow on the shaft

- Removes a temporary rotor bow during turbine warm up, before a turbine roll

Question 10

Is there an auto trip on high vibrations for the Unit 1 Main Turbine

Answer 10

No

Question 11

What is the purpose of the Main Turbine Thrust Bearing?

Answer 11

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

Question 12

What is the purpose of the Main Turbine Journal Bearing?

Answer 12

Support the weight of the turbine and generator rotors and restrict movement to the axial direction only

Question 13

What supplies Main Turbine Steam seals when starting up?

Answer 13

50# Aux Steam

Question 14

What supplies Main Turbine Steam seals during normal operation?

Answer 14

Leakage from exhaust of HPT and MFPTs

Question 15

What are the EHC pump auto starts?

Answer 15

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 16

What does SRA-1800 look for on U1?

Answer 16

Primary to secondary tube leak

Question 17

What maintains the bearing oil header pressure for the U1 Main Turbine?

Answer 17

1-SV-248, Main Turbine Oil Turbine Driven Lube Oil Booster Pump Discharge Safety Valve, maintains it at 25#

Question 18

What are the EHC loads?

Answer 18

• Main Feed Pumps
• Main Stop Valves
• Front Standard
• Main Control Valves
• Right Intermediate Valves
• Left Intermediate Valves

Question 19

What are the Unit 1 Main Turbine Trips from PLC

Answer 19

• Low Condenser Vacuum
• Overspeed 107%
• Oil Press (Bearing)
• Lo EHC header Press
• Lo Trip Header Press
• Loss of both DCS Power Supplies

Question 20

What are the 3 purposes of the Main Turbine and Control System?

Answer 20

1. Convert Thermal Energy into mechanical energy

2.Control the flow of steam entering the main turbine under normal conditions

3. Prevents steam from entering the main turbine in the event of emergency conditions

Question 21

Immediately following a Unit 1 Main Turbine Trip, which Lube Oil System pumps are running?

Answer 21

1. Turning Gear Oil Pump.
2. AC Suction oil pump.
3. DC Backup Oil Pump.
4. DC Emergency Bearing Oil Pump.

Question 22

U1 MT backup overspeed trip (IOPS) is what percent of rated speed?

Answer 22

110%

Question 23

What is the purpose of mist eliminator in U1 MTLO system?

Answer 23

Remove oil vapor from the discharge flow of the vapor extractors. Water vapors can go out roof!

Question 24

What is the purpose of the Intercept Valves?

Answer 24

Prevents overspeed on a turbine trip. The Reheat stop valve is a backup

Question 25

With U1 Main Turbine / Generator paralleled to the grid, the Main Turbine begins to overspeed. A Turbine trip will occur when the PLC senses turbine speed at

Answer 25

107% speed on 2/3 speed sensors

Question 26

What is the setpoint for the Low Bearing Oil Pressure on the Unit 1 Main Turbine?

Answer 26

Less than 8 psig for greater than 5 secs

Question 27

What is the Low EHC Header Pressure Trip for the Unit 1 Main Turbine?

Answer 27

Less than 1100 psig

Question 28

What is the Low Trip Header Pressure for the Unit 1 Main Turbine?

Answer 28

Less than 800 psig (2/3)

Question 29

When will the loss of all 3 speed sensors trip the Main Turbine?

Answer 29

Only if the unit is NOT paralleled

Question 30

What is the risk of operating without the MSRs in service?

Answer 30

Could result in water damage to the LP Turbine blades. Also results in lower efficiency.

Question 31

What is the result of a loss of steam seal and packing exhaust?

Answer 31

Loss of the system results in steam leaking from turbine to atmosphere or air entering turbine casings.

LOSS OF VACUUM

Question 32

What happens if the Steam Packing Exhauster trips?

Answer 32

Steam will come out!

Question 33

How do 1-SRV-10 (Steam Seal Pegging Valve) and 1-SRV-11 behaved while coming up in power?

Answer 33

SRV-10 will throttle as necessary until about 50% power. SRV-11 will be closed.

Question 34

What are the trips of the Unit 1 Main Turbine associated with SCW?

Answer 34

Low pressure at 36 psig
Low Flow at 499 gpm
High Temp at 81°C

Question 35

What is the vacuum trip set point from PLC for the Unit 1 Main Turbine at 100% power?

Answer 35

22.5” Hg