LOT 202.07 GSS

Question 1

• LOT 202.07 GSS*
• • *

What will auto start the GS HX Exhaust Fan B?

Answer 1

CD-504 OR CD-506 Open

GS Exhaust Fan A is normally running and has no autostarts.

• Note:*
• Opening either valve aligns condensate to the desuperheaters to condense steam if condensate isolated from GSS HX.*

Question 2

• LOT 202.07 GSS*
• • *

What MCR controls and indications are there for the GSS?

Answer 2

• CP009 Indications:*
• *Header Pressure**
• *Spillover Pressure**
• *Header Temperature**
• *Steam Supply Source**
• *GSS HX Exhaust Fan**
• *GSS HX Cond’t Side Pressure**

CP009 Controls:
GS Header Steam Isolation (GS014)
GS Header Steam Isolation Bypass (GS016)
Desuperheaters Cond’t Supply (CD504/CD506)
HP Turbine Spillover Bypass (GS079)
GS Steam Supply Selector (MS316/MS542)
Selects MSS or other unit’s ASS

Question 3

• LOT 202.07 GSS*
• • *

What supplies steam to the GSS?

Answer 3

• *Main Steam**
• > 185 psig*

Aux Steam from opposite unit

Question 4

• LOT 202.07 GSS*
• • *

What cools the gland steam condenser?

Answer 4

Condensate

Water goes to seal leakoff tank.

Air goes to atmosphere using GS exhaust fans.

• Note:*
• Desuperheaters condense steam when condensate secured to GSS HX.*

Question 5

• LOT 202.07 GSS*
• • *

What components does the GSS reduce leakage on?

Answer 5

• Turbines:*
• *Main Turbine**
• HP Turbine self-sealing at high powers*
• *SGFPTs**
• Valves:*
• *Throttle Valves**
• *Governor Valves**
• *Reheat Stop Valves**
• *Intercept Valves**

PV-6156 relieves to condenser to keep HP Turbine < 6 psig

• Note:*
• Reduces leakage on valves where stem leaves the bonnet.*