LOT 202.22 Circulating Water

Question 1

• LOT 202.22 Circulating Water*
• • *

What will auto start the CW Screen Wash Pumps?

Answer 1

Lead Pump:
Screen D/P > 6”
One Screen Running

First Lag Pump:
10 Sec after lead pump start, Pressure < 102 psig
4 Screens Running

Second Lag Pump:
10 Sec after 1st lag pump start, Pressure < 102 psig
7 Screens Running

If pump started on low pressure will not stop. (Must reset)

Note:
Spray valves will open when pressure > 90 psig

Question 2

• LOT 202.22 Circulating Water*
• • *

What reservoir temperature will require running all four CW pumps?

Answer 2

69 ˚F

Running all four CW Pumps < 69 ˚F will raise the plant’s condensate depression and lower overall efficiency.

Question 3

• LOT 202.22 Circulating Water*
• • *

What will energize the blue start permissive light on CP009?

Answer 3

Discharge Column filled*

• *Seal Pressure > 30 psig**
• < 50 psig starts standby pump*

Discharge Valve Closed

> 5 mins since last CW pump start

Can use Jet pump to draw air and moisture out of CW discharge column.

• Uses screen wash header as prime water

Question 4

• LOT 202.22 Circulating Water*
• • *

What is the CW pump securing sequence?

Answer 4

• Third and Fourth Pumps:*
• *Once Discharge MOV 80% Open, Pump Stops**

Discharge MOV fully Closes

• First and Second Pumps:*
• *Once 2^nd pump’s Discharge MOV 95% Open, BOTH PUMPS TRIP**

Valves Remain As-Is (95% Open / Fully Open)

Must wait 5 mins between securing pumps

Note:
PTL:**Bypasses 5 min TD but Discharge MOVs will still fully close

Question 5

• LOT 202.22 Circulating Water*
• • *

What is the CW pump start sequence?

Answer 5

• First Pump:*
• *10 sec after start, Discharge MOV opens to 40%**
• Second Pump:*
• *10 sec after start, 2^nd Pump’s Discharge MOV fully opens**

Once 2^nd Pump’s Discharge MOV is 35% open, 1^st Pump’s Discharge MOV fully opens

• Third / Fourth Pump:*
• *10 sec after start, Discharge MOVs fully open**

Pump trips:

• Discharge MOV NOT moving after 24 sec
• Discharge MOV NOT 35% open in 32 sec

Question 6

• LOT 202.22 Circulating Water*
• • *

What systems utilize the CW discharge piping?

Answer 6

OL-ACW

ECW Blowdown

• *LWPS**
• Connects to OL-ACW (MAB Chiller 11 in overhead)*

Question 7

• LOT 202.22 Circulating Water*
• • *

What will trip a CW pump?

Answer 7

• Starting Pump:*
• *Discharge MOV NOT moving after 24 sec**

Discharge MOV NOT ≥ 35% open in 32 sec

• Stopping Last 2 CW Pumps:*
• *Stopping 1 pump trips both**
• Discharge valves remain open*