G33 - RWCU

Question 1

What are the trips for the RWCU pumps?

Answer 1

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

Question 2

when will the F035 (blowdown to RW) Auto close?

Answer 2

high level in Aux Bldg Eq Drain tank level

Question 3

when can the F035 (blowdown to RW) be reopened after an auto closure?

Answer 3

After signal clears

Question 4

What are the purposes of RWCU?

Answer 4

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

Question 5

What should be done immediately after RWCU pump trips?

Answer 5

Isolate RWCU blowdown

Question 6

What group 8 isolations can be bypassed?

Answer 6

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

Question 7

What pre-pump AND post-pump modes of RWCU

Answer 7

Pre-pump < 100 psig RX pressure, pumps before Hx

Post-pump >100 psig RX pressure, Hx before pumps

Question 8

What are the power supplies for RWCU?

Answer 8

11/12

Question 9

why is pre-pump used when < 100 psig?

Answer 9

Ensure NPSH

Question 10

what percent must BWRT be to perform backwash?

Answer 10

<48%

Question 11

What level trips backwash transfer pump?

Answer 11

2”

Question 12

when do RWCU holding pumps start?

Answer 12

162 gpm

Question 13

what are the div 1 and 2 group isolation valves?

Answer 13

Div 1 - outboards: 250, 253

Div 2 - Inboards: 251, 252

Question 14

What is temp maintained at for demin inlet?

Why?

Answer 14

130 deg F.

140 deg F, Resin breaks down

Question 15

What flow can you have with 1 pump and no filters?

Answer 15

300 gpm

Question 16

what flow can you have with 2 pumps and no filters?

Answer 16

300-500 gpm

Question 17

What are group 6 isolation signals?

Answer 17

Rx level -41.6”

DW pressure 1.23 psig

Question 18

What are the group 8 isolation signals?

Answer 18

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

Question 19

how long after RWCU pump trip can it be restarted if a FD was in service?

Answer 19

2 minutes after flow has stopped

Question 20

how many pumps can be in service if suction is from bottom head only?

Answer 20

1

Question 21

how long can a test/normal switch be left in test?

Answer 21

8 hours

Question 22

why should the F046 or F041 AND F035 not be opened at the same time during blowdown

Answer 22

vacuum will be lost to radwaste

Question 23

what is RWCU blowdown used for? and where does it go to?

Answer 23

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)

Question 24

where can RWCU blow down to after group 6 isolation?

Answer 24

radwaste

Question 25

where can RWCU blow down go to after Aux bldg isolation?

Answer 25

Radwaste or main condenser

Question 26

how many RWCU pumps should be used when > 100 but < 200 psig Rx pressure?

Answer 26

one

Question 27

Why should pre-pump not be used >100 psig Rx pressure?

Answer 27

so you don’t exceed 200 deg F on ctmt penetrations 87 and 88

Question 28

when will the G36 -F003 Auto close on a Filter demin fault?

Answer 28

Hi Filter Demin Differential pressure 30 psid

Effluent post-strainer hi Diff pressure 10 psid

FD outlet flowlow of 36 gpm (20%)

Mode switch in filter with 80 second TD

Question 29

When will the G33-F033 close? (blowdown FCV)

Answer 29

Upstream flow controller <5 psi

Downstream controller > 140 psig and > 5% output