TACW

Question 1

What are the TACW pump auto starts?

Answer 1

• Low disch # at **
  155# (U1)
  145# (U2)

Question 2

What are the TACW pump trips?

Answer 2

• Load Con
• Load Shed
• Overload/Overcurrent

Question 3

What are the TACW Loads?

Answer 3

• Exciter Coolers
• Bus Duct Cooling
• H2 Coolers
• Stator Water Coolers
• Steam Packing Exhauster (U1)
• Gland Steam Condenser (U2)

Question 4

Where are the TACW pumps powered from?

Answer 4

• 11/21 A

- 11/21 B

Question 5

When do the TACW Inlet Valves to the Steam Packing Exhauster and Gland Steam Condenser (CMO-630/635) go closed??

Answer 5

• on an Extreme High Level

Question 6

Where does TACW fit in on the condensate system?

Answer 6

• TACW supply and return lines tap into the Condensate System between the HWP discharge and the Excess Flow Line to the CST

Question 7

What is TACW cooled by?

Answer 7

• CW in the TACW HX tubes

Question 8

What does CMO-600 do for the TACW system?

Answer 8

• Its the TACW bypass valve and it can only be manually operated

Question 9

What are the Auto action(s) that occur in the TACW Sys? (besides Pump auto start)?

Answer 9

• Steam Packing Exhauster and Gland Steam Condenser TACW Inlet valves close on an Extreme High Level

Question 10

During a Startup when is the TACW sys placed in service?

Answer 10

• Placed in service prior to drawing vacuum and placing steam seals in service

Question 11

Describe how makeup water is added to TACW System?

Answer 11

• Makeup water is supplied through a small bypass line around open cycle shutoff valve C-210, which is closed at this time.

Question 12

Above what temperature must TACW be in “Closed Cycle”?

Answer 12

• TACW from Hotwell temps

> 95°F (U1) (> 104°F (U2)) must be in CLOSED CYCLE

Question 13

With TACW in “Closed Cycle” is Cycle efficiency better or worse?

Answer 13

• Rejects heat to lake lowering cycle efficiency

Question 14

With TACW in “Open Cycle” is Cycle efficiency better or worse?

Answer 14

• Increases cycle efficiency

Question 15

What is TACW “Modified Open” cycle [Toad Cycle]?

Answer 15

• Open cycle with the TACW Hx
• Used to Reduce overall condensate temperatures
• Used up to 30% power to reduce overall condensate temperatures

Question 16

The Turbine Auxiliary Cooling Water System supply and return lines tap into the Condensate System between the:

A. Hotwell Pump discharge and the Excess Flow Line to the Condensate Storage Tank.

B. Excess Flow Line to the Condensate Storage Tank and the SJAE Condensers.

C. SJAE Condensers and the tap-off for the Turbine Exhaust Hood Sprays.

D. HWP recirc line and the CBP suction

Answer 16

A. HWP discharge and the Excess Flow Line to the CST.

Question 17

Describe the flowpath of the TACW Sys in “Closed Cycle”?

Answer 17

• One of two TACW pumps takes suction on the common return header and discharge through the TACW Heat Exchanger. The flowpath is then through the parallel loads into a common return header and back to the pump suction.

Question 18

Describe the flowpath of the TACW Sys in “Open Cycle”?

Answer 18

• TACW pump suction is supplied from the HWP discharge header through open cycle shutoff valve C-210.
  One of two TACW pumps discharge through Heat Exchanger Bypass Valve CMO-600 to the parallel loads.
  The flow exits the loads to a common return header and returns to the HWP Discharge Header through the Open Cycle Shutoff Valve C-249

Question 19

With regards to TACW, what happens if power is lost to Train B and cannot be restored

Answer 19

You lose TACW cooling which cools the stator with will require the unit to be tripped