LOT 202.03 Main Turbine

Question 1

• LOT 202.03 Main Turbine*
• • *

What will trip the turbine?

Answer 1

Electrical Overspeed (110%)

Mechanical Overspeed (111%)

Condenser Vacuum - Low (21.0”)

Thrust Bearing Wear (±40 mils)

P-14 (SGWL 87.5%)

P-16 (Rx Trip)

SI

Bearing Oil Pressure - Low (6.0 psig ± 1)

Stator Cooling Water D/P - Low (19 psid) [40 sec TC]

AMSAC

Generator Trip

Manual (Local/MCR)

Question 2

• LOT 202.03 Main Turbine*
• • *

What will auto open/close the steam chest drain valves? (4 total)

Answer 2

• Auto Open:*
• *≥ 20% power w/ high drain pot level**

< 20% power

• Auto Close:*
• *≥ 20% power w/ low drain pot level**

20% override: Will remove “< 20% power” auto open signal and allow drains to cycle on drain pot level.

Note:
Steam line drains on CP006 and Turbine steam chest drains on CP007

Question 3

• LOT 202.03 Main Turbine*
• • *

How many stages does the HP turbine have?

Answer 3

• *8 Stages**
• 1 Impulse / 7 Reaction*

LP turbines have 10 reaction stages

Question 4

• LOT 202.03 Main Turbine*
• • *

When will the governor and IVs close to prevent a overspeed condition?

Answer 4

103%

• Note:*
• Governor and IVs will reopen at 100%*

Question 5

• LOT 202.03 Main Turbine*
• • *

What is the flowpath of the steam as it enters the main turbine?

Answer 5

• *Enters through throttle valves (4)**
• 2 per steam chest*

Flows into Steam Chests (2)

• *Flows through Governor Valves (4)**
• 2 per steam chest*

Directed to steam chest quadrant

• *Flows axially through HP Turbine**
• 1 Impulse Stage / 7 Reaction Stages*

Flows through Cross Under piping to MSR

• *Flows through Crossover Piping to RSVs (6)**
• 3 per MSR*
• *Flows through IVs (6)**
• 3 per MSR*

Flows through 3 LP turbines

Goes to Condenser

Question 6

• LOT 202.03 Main Turbine*
• • *

What will auto open the exhaust hood spray valves?

Answer 6

Crossover Steam Pressure < 15%
AND
Turbine Speed > 600 RPM

• Maintains spray pressure 116 psig (40 gpm)
• Alarm set at 175 ˚F

Note:
Controlled on CP007

Question 7

• LOT 202.03 Main Turbine*
• • *

Where is the Turbine Supervisory Instrumentation physically located?

Answer 7

EAB 35’ Relay Room

Subsystem of the IVMS.

• Note:*
• Alarms acknowledged on the Human Machine Interface (HMI). (Behind CP004)*

Question 8

• LOT 202.03 Main Turbine*
• • *

Where does the extraction steam go on the LP Turbine?

Answer 8

• Turbine End:*
• *4^th Stage: FWH 14A/B**
• *6^th Stage: FWH 15A/B/C**
• *8^th Stage: FWH 16A/B/C**
• Generator End:*
• *2^nd Stage: FWH 13A/B**
• *6^th Stage: FWH 15A/B/C**

Question 9

• LOT 202.03 Main Turbine*
• • *

Where does the extraction steam go on the HP Turbine?

Answer 9

4^th Stage Extraction: FWH 11A/11B

Exhaust: DA (FWH 12)

Question 10

• LOT 202.03 Main Turbine*
• • *

Where is the thrust bearing located on the main turbine?

Answer 10

Between LP12 and LP13

Question 11

• LOT 202.03 Main Turbine*
• • *

Where are the drain valves located in the main turbine system?

Answer 11

• Steam Chest Drip Legs:*
• *Inlet to steam chest (4)**
• 1 per steam line*

Turbine Drain Valves:*
Between GVs and HP Turbine (4)
HP Turbine 1st Stage (1)
Crossunder lines to MSR (6)

The turbine drain valves auto open on turbine trip and loss of power/air.

Note:
Drains to main condenser

Question 12

• LOT 202.03 Main Turbine*
• • *

What are the turning gear start permissives?

Answer 12

Bearing Oil Lift Pressure > 850 psig

Bearing Oil Header Pressure > 3.7 psig

Turning Gear Engaged

Turbine at zero speed

Controlled locally and CP007.

Question 13

• LOT 202.03 Main Turbine*
• • *

How are the throttle and governor valves controlled during a turbine startup?

Answer 13

• 0 RPM - 1700 RPM:*
• *Governor Valves full open**
• *Throttle valves control speed**
• 1700 RPM - 1800 RPM:*
• *Throttle valves full open**
• *Governor valves control speed**

Governor valves open in a 2, 3, 1, 4 pattern to minimize stress on the HP turbine 1st stage.