MT Ctrls

Question 1

What is IOPS powered by?

Answer 1

CRIDS I, II, III

Question 2

What does IOPS do?

Answer 2

• Backup Overspeed protection at 110% (Hardwire trip)
• Its energize to trip (2/3) passive probes

Question 3

What is the DCS power supply?

Answer 3

BOP Battery System (250 VDC) thru inverter

- BLC/CLC backup to inverters **

Question 4

What is the DCS purpose?

Answer 4

Supply hydraulic fluid (motive force) for stop/control valve operation during normal and emergency conditions.

Question 5

What does hood spray protect against?

Answer 5

Prevents LPT blade overheating

Question 6

How fast do 10% and 20% manual runbacks go?

Answer 6

100 MW/min

Question 7

When is a loss of a MFP runback enabled?

Answer 7

Unit 1 = 54.5%
Unit 2 = 60%

Question 8

When a MFP is lost, how far do the main turbines runback?

Answer 8

Unit 1= 625 MW
Unit 2 = 752 MW

Question 9

What will the Load Target be for an Over Power Delta Temperature and Over Temperature Delta Temperature Runback be?

Answer 9

• Target Load to 30 MW

Question 10

When is power load unbalance armed?

Answer 10

Armed when 1st Stage Press > 40% (from DCS)

Question 11

What is the Main Turbine Load Reference for a power load unbalance?

Answer 11

Load Ref to 30 MW

Question 12

What does the Droop Speed override signal do?

Answer 12

• Biases Load Ref signal which closes down on control valves and Intermediate Valves
• Protects from overspeed condition with output breaker closed

Question 13

When is the Droop Speed override signal active?

Answer 13

> 1805 rpm

Question 14

What is the primary tripping device of the Main Turbine?

Answer 14

• Trip Block Assembly

Question 15

What is the one turbine trip input from TSI?

Answer 15

Thrust Bearing position

Question 16

Will a failure of all 3 PLC speed sensors on the Turbine give you a turbine trip while on the grid?

Answer 16

NO!! Only if you’re NOT paralleled.

Question 17

What is the load target for an ATWS runback?

Answer 17

1 MW

Question 18

What is the purpose of Power Load Unbalance?

Answer 18

• Provides overspeed protection in the event of a large load rejection
• Used only on ATWS when the MT also fails to trip with manual AMSAC or Solenoid Trip

Question 19

Which valves will reposition when resetting the Main Turbine?

Answer 19

The Reheat Valves open

Question 20

What do the combined stop and intercept valves do for the turbine?

Answer 20

protect against overspeed of the turbine from residual steam from the MSRs on a turbine trip

Question 21

If moving the turbine in MW Control IN, what happens?

Answer 21

Load reference will ramp toward the Load Target and the PLC sends a signal to the control valves to match Load Reference.

Question 22

When in MW control IN, what happens when lake temperature moves around?

Answer 22

Valves will move around to maintain a constant MW value

Question 23

When in MW control OUT, what happens when lake temperature moves around?

Answer 23

Valve position stays constant, but MWs will move around

Question 24

What is unique to the Power Load Unbalance Runback?

Answer 24

Forced to MW OUT. All other Runbacks are forced to MW IN

Question 25

What kind of probes does IOPS use?

Answer 25

passive probes

Question 26

With regards to the solenoids for the Trip Block assembly, the MT will trip when how many solenoids do what?

Answer 26

2/3 de-energize

Question 27

When an operator places MT DCS to MW IN, the values for the Load Target, Actual Load and Load Reference will go to what value?

Answer 27

the MW value of the Actual Load

Question 28

The power load unbalance system is armbed above ____% and looks for a large rate of change in generator ____ per second

Answer 28

40% and amps

Question 29

When is turbine warming required for Unit 1? And what is used?

Answer 29

Chest warming required < 460ºF Shell warming required < 250ºF Utilize SV2