Core Flood System Flashcards
What are the 3 phases of a LOCA?
- ) Blowdown - rapid loss of coolant
- ) Refill - both CFT discharge
- ) Reflood - HPI & LPI Injection
What is Function of CFT System?
Passive system that provides core protection following intermediate to large breaks where combined volume is sufficient to cover 3/4 of core.
What is design bases for ECCS?
HPI, both CFT and LPI provide protection to core during worst case leak (Double ended pipe rupture of cold leg at discharge of RCS)
What 5 acceptance criteria’s is ECCS system designed to meet?
1) Peak cladding temp < 2200 F
2) Cladding oxidation < 17% thickness
3) H2 generation < 1% of all that could be generated
4) Coolable core geometry
5) Long term cooling
What is the required CFT boron concentration?
2270 - 3500 ppm
What is TS and admin limits for CFT level? What are these limits based on?
Admin - 13 +/- 0.3 ft TS - 13 +/- 0.4 ft
High limit - maintains adequate gas volume to ensure proper injection and fully discharge contents
Low limit - Ensures both CFTs provide enough inventory to cover 3/4 of core
What is TS and admin limits for CFT pressure? Why are these limits based on?
Admin - 600 +/- 20 psig TS - 600 +/- 28 psig
High limit - limit loss of coolant through the break
Low limit - Has enough pressure to properly discharge into core per analysis
Describe the motor operated vent valve operation on CFTs.
Vent valve is used for over pressure adjustments during pressurization of CFTs and are equipped with flow limiting orifices sized to minimize loss of nitrogen if failure occurs. It is sized to allow time to align nitrogen before reaching minimum pressure.
What panel is position indication for CF-2 located?
C-18
What are the NDTT limits of CFTs?
Temp must be greater than 65 degrees F when pressurized above 140# CFT pressure limited < 25# when delta T between CFT metal and N2 temp > 100 Degrees F
When are CFT outlet MOVs operated and what are the alarms associated with them?
MOVs are opened prior to reaching 800# and closed prior to 700#
If RCS pressure > 750# and MOV not full open a local horn and flashing red lights on C16/C18 will illuminate
If RCS pressure < 700# and MOVs not fully closed annunciator K10-E5 will come in
What is the interlock for MOV outlets associated with DH suction valves?
CV-1050 is interlocked with CV-2415 to close if CFT outlet not 100% closed to prevent overpressurizing DH suction. CV-1410 interlocked with B CFT outlet (CV-2419)
How many level and pressure instruments are each CFT equipped with and how many are required?
Each CFT equipped with 2 level and pressure instruments on C16/18 TRM 3.3.5 require only 1 of each for each CFT to be operable.
What is the TS/TRMs are required for CFTs and the modes of applicability?
TS 3.5.1 requires both CFTs operable in modes 1,2 and 3 (RCS pressure > 800#) TRM 3.3.5 requires 1 level and pressure instrument for each CFT (same applicability as TS)
When are the CFT outlet MOVS prohibited from being opened?
RCS temperature < 259 degrees and RV head installed MOV outlet valve breakers are prohibited from being closed Exceptions: ASME code testing or CFT pressure < max RCS pressure for temp allowed by PT curves per TS 3.4.3
