Plant Cooling Water Flashcards
What are the purposes of plant cooling water (PW)?
Remove heat from:
TC, NC, AR pump seal coolers
Reject heat to CW
Fill main condenser water boxes and CW system during startup or after maintenance
Provide water to the CW screen wash area
Provide water to the chlorine injection system acid injection static mixers
What is the normal PW supply header pressure?
50 psig with one pump running
Where is the alternate return path for PW?
it returns to the #2 cooling tower if the normal path is not available
What powers the PW pumps?
NBN-S01 & S02
What is the minimum canal level needed to prevent air binding of the PW pumps?
19 feet 0”
What cools the PW pump motor bearings?
Oil lubricated and air cooled
What pressure does the standby pump usually start at?
it will auto start at 40 psig of discharge pressure from the operating pump
What are the circ water fill valves used for?
to line up PW to fill the main condenser via the CW main condenser inlet line for start up
What are the outlet valves to the TC and NC heat exchangers throttle to in order to get the desired flow rate?
33% open
Which pressure is higher, PW or NC and why?
PW is higher in order to minimize the chance of getting radioactive contamination in the CW canal from the NC system if there were to be a leak.
What is the high differential level across the trash screens that will cause us to have to have them removed and cleaned?
12”
What happens if a condition that causes a reduction or loss of flow in the PW system cannot be corrected?
The plant will have to be manually tripped due to higher temps in the NC, TC, and AR systems.
