Systems Exam 2 - CVCS Flashcards
(51 cards)
PS-5385/5385A (upstream of PCV-131) provides local pressure indication and HELB alarm at…
≤ 200 psig
Closure of 8152 or 8160 (CIV downstream of orifice valves) will cause relief valve 8117 to lift and discharge to the PRT, resulting in a….
LOCA. Operator action required to isolate LTDN at this point.
Letdown HX Outlet Temp
95°F
(inlet temp is 260° F)
Purpose of the mixed bed demins
(2 mixed beds, one in use at a time)
Use lithiated resin to remove corrosion products by filtration and ionic impurities (chemical contaminants and fission products) from the RCS
VCT Backpressures
→H2 pressure maintained around 25 psig
→ >15 psig for Seal #1 backpressure for adequate flow to #2 Seal
→10 psig when degassing to prevent reverse pressurization on #2 RCP seal
The CCP alternate miniflow relief valves recirc to where?
RWST
(lift at 2200 psig)
What PDP speed is required to maintain adequate oil pressure?
55 gpm. Otherwise the PDP is likely to trip on low oil pressure (4 psig) 90 seconds after breaker closure.
How does PDP speed fail on loss of air?
to its maximum speed
(98 gpm)
What is required to start the PDP?
→8109 must be open (PDP recirc valve)
→No train A BO (OL)
→No train A SI (AL)
→HS taken to START
Note: If HS is taken to START with 8109 closed, it will auto-open. Once 8109 is open, PDP HS will need to be taken back to START to start the pump.
PDP Trips
→Train A SI (breaker is load shed/shunt tripped)
→Low Lube Oil Pressure (4 psig, >90 sec after pump start)
→Undervoltage
→Overcurrent
What is the power supply for LCV-459/460?
How do they operate?
→uED1-1
→AOVs fail closed on loss of air or power
→power supplied from Train A only
How do 8149A/B/C Orifice Isolation Valves operate?
HCV-128 RHR to Letdown Line power supply and use
→Hagan controller powered from uPC1
→AOV, fails closed
→Used when RHR is aligned to letdown for Modes 4-6
→Used full open; flow is controlled via PCV-131.
→can come from either train RHR
TCV-129 CVCS Demin Bypass purpose and setpoints
→powered from uED1-1
→diverts to VCT; bypasses CVCS demins at 135° F (input from TIS-129) and BTRS at 155° F (TIS-382)
→three position handswitch: Demin, Normal, VCT
→if it diverts to VCT on high temp, when the temp comes back down, it will remain in VCT; must take handswitch back to Demin to change valve position back to demin
LCV-112B/C VCT Outlet Auto Close
→VCT Lo-Lo of 2% on BOTH LT-112 and LT-185
→SI
(also switches charging suction source to RWST on VCT Lo-Lo of 2%)
FCV-121 Alarms
→Lo Flow Alarm ≤ 55 gpm
→Hi Flow Alarm ≥ 150 gpm
→Mini flow in auto is 55 gpm
→fail open AOV fed from FT-121
→charging flow indication limited to 270 gpm due to FT-121
(Normally measures charging flow + RCP #1 seal leakoff. After SI, it will measure RCP Seal Injection flow.)
→8145 Aux Spray should not be used when…
→8145 Aux Spray shall not be used when…
→ΔT exceeds 320° F between charging out of Regen Hx and PZR temp
→ΔT exceeds 625° F
VCT Level Control (Level Channel 112) makeup start and stop setpoint
→Makeup starts 46%
→Stops at 56%
(10% level ≈ 200 gal)
What occurs when you raise/lower Letdown HX outlet temperature?
→Raise T: negative reactivity due to releasing boron
→Lower T: positive reactivity due to absorbing boron in mixed beds
→Per SOP-103, when placing a standby bed in service, special care should be taken not to add positive reactivity due to absorption of boron in the bed
RCS Limits on Letdown Flow (per # of demins)
→ ≥500°F in RCS, limit letdown flow to 140 gpm
→ <500°F w/1 demin in service, limit flow to 170 gpm
→ <500°F w/2 demins in service limit flow to 195 gpm
Do Hagan controllers work automatically?
No.
What is the power supply for the PDP?
uEB1
Where does Normal Letdown tap off of?
Loop 3 intermediate leg
Where does Excess Letdown tap off of?
Loop 1 Intermediate Leg
