G33 - RWCU Flashcards
What are the trips for the RWCU pumps?
CLAMS
C - Cooling water high temp 195 degF L - Low suction flow < 70 gpm, 15 sec TD A - Any suction valve not full open M - MPD S - SLC handswitch initiation A&B
when will the F035 (blowdown to RW) Auto close?
high level in Aux Bldg Eq Drain tank level
when can the F035 (blowdown to RW) be reopened after an auto closure?
After signal clears
What are the purposes of RWCU?
minimizes heat transfer surface functions
limits rad levels
discharges excess rx water to either the hotwell, or to RW
Prevents thermal stratification with no recirc pumps running
What should be done immediately after RWCU pump trips?
Isolate RWCU blowdown
What group 8 isolations can be bypassed?
Differential flow high 79 gpm for 45 seconds
All room temps: MSL tunnel temp, RWCU pump/valve/hx rooms
Loss of LDS logic control power
What pre-pump AND post-pump modes of RWCU
Pre-pump < 100 psig RX pressure, pumps before Hx
Post-pump >100 psig RX pressure, Hx before pumps
What are the power supplies for RWCU?
11/12
why is pre-pump used when < 100 psig?
Ensure NPSH
what percent must BWRT be to perform backwash?
<48%
What level trips backwash transfer pump?
2”
when do RWCU holding pumps start?
162 gpm
what are the div 1 and 2 group isolation valves?
Div 1 - outboards: 250, 253
Div 2 - Inboards: 251, 252
What is temp maintained at for demin inlet?
Why?
130 deg F.
140 deg F, Resin breaks down
What flow can you have with 1 pump and no filters?
300 gpm
what flow can you have with 2 pumps and no filters?
300-500 gpm
What are group 6 isolation signals?
Rx level -41.6”
DW pressure 1.23 psig
What are the group 8 isolation signals?
M - Manual isolation initiation
S - SLC actuation
T - Steam tunnel hi temp 185 deg F (E31)
Ex area temps: (E31)
Pump 170 deg f
Valve 135 deg f
HX 120 deg f
D - diff flow hi 79 gpm for 45 seconds (E31)
L - Low reactor water level -41.6”
L - Loss of LDS control power to LDS logic (E31)
N - Non Regen outlet temp (FD inlet temp) high 140 F
how long after RWCU pump trip can it be restarted if a FD was in service?
2 minutes after flow has stopped
how many pumps can be in service if suction is from bottom head only?
1
how long can a test/normal switch be left in test?
8 hours
why should the F046 or F041 AND F035 not be opened at the same time during blowdown
vacuum will be lost to radwaste
what is RWCU blowdown used for? and where does it go to?
used for startup to reject water due to 60 gpm entering reactor from CRD with no steam exiting.
reject to hotwell or aux bldg eq drain (hotwell is preferred)
where can RWCU blow down to after group 6 isolation?
radwaste
