Circulating Water

Question 1

What are the major system trips associated with the Circulating Water system?

Answer 1

Big ones:

Discharge valve not full open - 90s time delay from reaching <90% open (allows the valve 90s to open on pump start)

Condenser room flooding - 3” above the floor

Question 2

What valves/pumps/breakers are affected by the condenser room flooding logic?

Answer 2

• Directly trips circulating water pumps
• Pump trips causes pump discharge valves to go closed
• Closes condenser water box inlet and outlet valves F001A/B and F002A/B
• Closes Turbine Building PSW Isolation valves 2P41F316A/D (1P41F310A/D) - CANNOT BE OVERRIDDEN
• Trips 4160 A/B normal and alternate breakers
• Loss of 4160 A/B causes loss of power to the ASDs, which results in a loss of the Rx Recirc Pumps (not a direct trip!)

Question 3

What is the time delay associated with restarting a tripped Circulating water pump?

Answer 3

90s time delay to restart the pump
Discharge valve will go closed on the pump trip, but does not have to be fully closed (or even close at all) to restart the pump after 90s

Question 4

Which systems provide the sealing water for the Circulating water pumps?

Answer 4

U2 - Demin water

U1 - Sanitary water

Question 5

What chemical is added to the circulating water system and why is it added?

Answer 5

Sodium Hypochlorite

To prevent biological fouling

Question 6

What are some of the indications of condenser tubes leaking in the circulating water system?

Answer 6

• Increased condensate demineralizer influent conductivity
• Decreased lifetime of condensate demineralizer units
• Increased Condensate Storage Tank inventory
• Annunciator “Polishing Demineralizer Trouble”

Question 7

Is a SCRAM required on condenser room flooding?

Answer 7

Per 34AR-650-164-2

• IF reactor has scrammed, enter 34AB-C71-001-2, Scram Procedure.
• IF reactor NOT scrammed, enter 34AB-C71-001-2, Scram Procedure, AND SCRAM reactor.
• Enter 34AB-P41-001-2, Loss of Plant Service Water.
• Enter 34AB-B31-001-2, Reactor Recirculation Pump(s) Trip Or Recirc Loops Flow Mismatch.
• Enter 34AB-N71-001-2, Circulating Water System Failure.
• Notify Unit 1 operator of possibility of Unit 1 Condenser Room flooding condition.