CORE FLOOD Flashcards
Power operation with one idle RCP in each loop shall
be restricted to how long? If the reactor is not
returned to an acceptable RC pump operating
combination at the end of the time period, the reactor
shall be in what condition in the next how long?
24 hours
24 hours, then the reactor shall be in hot shutdown
condition within the next 12 hours
Each safety related snubber shall be operable.
Whenever the system protected by the snubber is
required to be OPERABLE with one or more subbers
inoperable, within 72 hours replace or restores the
inoperable snubbers to OPERABLE status and
perform engineering evaluation OR what do you have
to do ?
DECLARE THE ATTACHED SYSTEM INOPERABLE
AND FOLLOW THE APPROPRIATE ACTION
STATEMENT FOR THAT SYSTEM.
Core flood
Purpose
Floods core when RCS pressure drops below 600#
Basis for Core Flood
Need both CFT’s to completely re-flood core for hot
and cold line breaks
10CFR50.46 acceptance criteria, injects borated water
for what reasons? (5)
Limit peak cladding temp < 2200 degF
- Limit cladding oxidation < 17% of total cladding
thickness
- Limit hydrogen generated zirc-water reaction <1%
if all cladding were to react.
- Ensure a coolable core geometry
- Establish long term cooling for DHR
Minimum required for ECCS analysis for core flood
2 CF tanks
1 HPI train
1 LPI train
CF-V-1A/B
What position are the valves normally positioned?
Normally OPEN
Procedurally
During heat up position valves which way at what
pressure
During cooldown
Open valves when RCS between 650# and 700#
during heatup
Close valves when RCS between 700# and 650#
during cooldown
If valves out of position for current RCS pressure what
alarm do you get?
Alarm D-3-8
CF-V-1A/B
Power supply
Breaker normally what with EST applied
Where do you have indication as required by T.S?
1C ESV MCC
Breaker normally open
Still have indication on ES status panel as required
by T.S.
Core Flood Nozzle
Limits flow out of the reactor vessel in the event of
what?
In the event of a core flood line rupture
CF Tank sample/drain outlet isolation, CF-V-2A/B
Power supply
Closes on what ES on which train?
1A ESV MCC
CLOSE on 4# ES (A’ Train) and RTI (A’ Train)
CF Tank sample/drain CF-V-20A/B
Power supply
Interlocks (4)
1F DC (B’ train) via XCL
Interlocks (closed on ALL)
1.) Loss of DC
2.) Loss of IA
3.) 4# ES (B’ train)
4.) RTI (B’ Train)
CF tank vent to vent header, CF-V-3A/B
Power supply
Bkr normally what with EST applied?
Powered from 1A/B RW MCC
Breaker normally open, EST applied
CF tank makeup (N2 or H20) isolation CF-V-19A/B
Power supply
Interlocks
1M DC via XCR
Interlocks all closed on the following:
1.) Loss of DC
2.) Loss of IA
3.) 4# ES (A’ or B’ train)
4.) RTI (A’ or B’ train)
Operating parameters
Nitrogen Makeup:
Normal band
Psig overhead alarm D-2-7/8
Psig required by tech specs
Normal band 590-610 psig
Psig overhead alarm 585-615 psig
Psig required by tech specs 575-625
Level/Boron Makeup
Can fill tanks from MU system, but not while what?
Normal bands?
But NOT WHILE CRITICAL
Normal band: 11.35 – 11.81 ft
Boron
Normal band
Required by tech spec band
Normal band: 2350-2750 ppmB
Required by tech spec band: >2270 ppmB
Level/Boron Makeup
Temperature
Normal band
CF tank metal temperature low alarm?
Normal band >70 degF but <140 F
CF tank metal temp low alarm: 75 F
Limits and precautions
OP-TM-213-000
CF level indication will be erroneously high with the
tank depressurized. Level indication is approximately
how many inches above actual when CFT pressure is
what?
7” above actual when CFT pressure is 0
Limits and precautions
OP-TM-213-000
To avoid an invalid reading, do not allow CF-Tank level
to exceed how many ft? exceeding that limit will result
in filling the CF tank what with water?
Exceeding 14ft
Filling the CF tank reference leg with water
During startup, the core flood tank isolation valves
must be in what position? When the reactor coolant
system pressure rises to what pressure? But is less
than what pressure?
Core flood tank isolation valves must be OPENED
when reactor coolant system pressure rises to 650
psig, but is less than 700 psig.
During normal reactor plant cooldown, what position
do core flood tank isolation valves go to when reactor
coolant pressure drops to less than what pressure but
greater than what pressure?
Core flood tank isolation valves CLOSED
Normal vent path
Waste gas header, normal vent **
