Component cooling Flashcards
Purpose of CC system:
- Heat removal from plant components during normal operation, plant cooldown and post accident.
- Intermediate heat removal system:
a. Removes heat from potentially radioactive components
b. Transfers heat to SX (Ultimate heat sink).
CC design
During NORMAL operation, the temperature of the CC HX outlet should not exceed 105F, based on max SX inlet temp of 100F.
During the INITIAL PHASE OF RHR COOLDOWN, the temperature may be permitted to increase to 120F for up to 3 hours.
The 120F CC design limit is based on ______________ limits.
Thermal barrier
3 pumps/ 2 HXs yields a CD rate of _____ with RHR on _____.
40F/hr; maximum
CC pump auto starts (3)
- SI
- UV on ESF bus (20 seconds)
- Discharge pressure <=85 psig (4 sec TD, blocked on emerg start of DG for 20 seconds)
The low discharge pressure auto start of CC pumps occurs at ______psig, has a ______seconds time delay and is blocked for ______ seconds after ____________.
<=85psig
4
20
EDG emergency start
U0 CC pp will only auto start if _________
A or B CS in PTL
U-0 pp control power fuses installed
U0 PP breaker racked into that bus
RSP C/S in _____ will/will not inhibit auto pump starts.
Local; will not
Normal temperatures, pressures and flow rates:
70-100F, min temp limit 60F for RCP thermal barriers
135-140 psig, min press 85# max press 150#
Flow rates:-4800 GPM at 130#
-7000 GPM runout
-500 GPM minimum
CC201A and CC202A open at_____
CC201B and CC202B open at _____
CC201A and CC201B auto close when level rises ______ above setpoints and following a _____time delay.
CC202A and CC202B close at ______
30%
22%
10% above setpoint and following 5 minute time delay
90%
CC17 auto _____ on a _______ signal.
closes; radiation
Pump trips:
- Low surge tank level 13%
- OC on phase A or C
- UV
- Ground over current
The U-0 CC pp will not auto trip on level of 13% if ______.
Control power fuses are removed from the associated CC01PA or CC01PB breakers.
LT670/LSL072 side of surge tank trips the _____ pumps at______. Also operates PW makeup valve CC-182 to maintain level _______.
LT676/LSL073 side of surge tank trips the _____ pumps at _____. Also operates WM makeup valve CC-183 to maintain level ________.
A/O CC; 13%; 42-55%
B/0 CC; 13%; 50-55%
With common CC HX aligned to Unit 1, ____ supplies U1 A and B safety loops and __________ safety loop. U2 supplies U2s ________only.
U1; U2 A train; B safety train loop only
All CC relief valves have a setpoint of ______with the exception of the relief associated with _____ which lifts at _____.
150#; RCP thermal barrier; 2485#
CV-182 fails _____ and CV-183 fails _____ on loss of IA.
closed; open
CC surge tank functions: (4)
- Exp and Contraction of CC from temp changes
- Immediate sources of makeup water in CC leak
- Suction head for CC pumps
- Accommodates in-flow of RCS from RCP thermal barrier heat exchanger tube rupture for approximately 3 minutes.
The CP fuses for ______ pumps do/do not need to be installed for the U0CC pump to auto start and do/do not need to be installed for low level trip.
A and B
Do not
Do
0/1/2 SX007 is used to _______ to the CC HXs; a local _____ must be closed to perform this action.
Throttle cooling flow; disconnect
Low flow alarm for CC from each individual RCP MOTOR cooling comes in at _____. Normal flow from each thermal barrier is approximately____ with a low flow alarm of _____.
170 GPM
40 gPM
38 GPM
On either side of containment is a ______operated valve for both the _____cooling return header and the ______ cooling return header. All 4 valves close on a ________. Outside containment return from the ______ cooling header closes on high______ of ______.
Motor
motor
thermal barrier
Phase B signal
Thermal barrier
flow rate of 240 gpm
The CC supply header to the RCPs has two ______operated valves located inside/outside containment. These valves auto _____on a ______signal.
Motor
Outside
Close
Phase B
The Excess LD heat exchanger CC supply and return valves are both ______ operated valves located inside/outside containment that fail ______ on loss of IA and auto _____ on a _______ signal.
Air
Outside
Closed
Close
Phase A
