CVCS Flashcards
Describe LCV-459 & 460
- air open, fail close
- auto close on Lpzr < 17% (459-control chnl)(460 b/u)
- all three orifice valves must be closed to manually close 459/460
Norm value regen hx
Letdown inlet
Letdown outlet
Charging inlet
Charging outlet
545 degrees
290
130
480
Describe Orifice isolation valves CVCS-8149 A, B, & C
- air open, fail close with nitrogen b/u
- CS on VB2 and HSDP
- close on phase A
- close on Lpzr < 17%
- close if LCV-459 or 460 off open seat
- close loss of all charging
- close if LTDN hx room >/= 150 degrees (HELB)
Describe CIV CVCS-8152
- air open, fail close with nitrogen b/u
- outside CNMT
- close on phase A
- close on LTDN hx room >/= 150 degrees (HELB)
Describe HCV-133
- provide letdown flow via RHR when RCS d/p is too low to develop flow via CVCS
Describe Letdown hx
- CCW cooled hx
- removes heat from letdown to protect resin and RCP seals
- TCV-130 maintains ~100 degrees outlet (controls CCW flow)
Describe PCV-135
- air operated back pressure control valve
- maintains 350 psig downstream of orifices (prevent flashing)
- nominal set point is 58.3%
- controls pressure of RCS when solid (?)
Describe TCV-149
- air operated, three way globe valve
- directs flow to demins or VCT
- fails to VCT(loss air)
- auto bypass to VCT if temp at 136 degrees
Describe demineralizers MB (2) Cat bed (1) Deborating (2) Filters (2)
MB- maintain RCS chemistry(remove unwanted ions)
CB- reduce RCS pH by removing Li+ ions
DB- remove Boron when [B] so low it would take a lot of water to dilute (1-1 is MB used during forced O2)(1-2 is anion bed used to remove boron)
Ltdn filter- collects resin fines & other particulates
How does temperature affect resin beds affinity for boron
- increased temp, saturated bed will release boron
- reduced temp, saturated bed will absorb more boron
boron sweats!
Purpose of Zinc injection system
- reduces source term
- reduce general corrosion of primary system materials
(Materials made up of alloy 600)(pwscc) - injects downstream of seal water hx, upstream VCT
Describe Argon injection
- increase source term to enhance ability to detect primary to secondary leak
- argon has short half life (1.8 hrs) and non-condensible => able to be monitored by SJAE rad monitor, injected into zinc injection line
Describe LCV-112A
- air operated, fails to VCT (loss air) three way divert valve
- at set point (norm 40%) valve will divert flow from VCT to LHUTs ( mods using prop cntrlr)(LT-114)
- can be controlled manually
- trip signal from LT-112 (87% Lvct)
Purposes of VCT
- NPSH for CCP’s
- maintain chemistry (H2 /N2 for O2 control)
- maintain chemistry (degas RCS)
- means to add boric acid and pri water to RCS
- back pressure on #1 Seals
LT-112 outputs
- trip open signal @ 87% Lvct (ovrds mod sig)
- stop auto m/u @ 24%
- start auto m/u @ 14%
- 1/2 input to xfr CCP suction to RWST @ 5%
- ind on VB-2
LT-114 outputs
- modulates LCV-112A divert to LHUTS @ 40% (based on cntrlr set point)
- 1/2 input to swap CCP suction to RWST @ 5%
- ind @ HSDP & ppc
Describe CCP’s
P.S.
1-1
1-2
1-3
- hi head ECCS pumps
- normal charging (1-3, then 1-2/1-1)(1-3 is air cl)
- return letdown flow to RCS
- cool regen hx
- seal injection
P.S
1-1 F
1-2 G
1-3 G (air cooled)
Auto starts on ECCS CCP
Manual start
SI
XFR to diesel
(Auto start will not wait for oil Press)
Manual will not start in man if oil Press < 9psig
Trips on ECCS CCP
O.C.
Xfr to diesel (load shed)
CCP 1-3
Trips
Air cooled
UV
O.C.
Xfr to diesel
What will cause CCP suction to swap from VCT to RWST?
LCV-112B, 112C close
8805A, 8805B open
Both LT-112 & 114 = 5% Lvct
SI
As soon as one RWST valve is f.o., VCT valves will shut
Describe purpose, interlock and p.s. for 8107 and 8108
Close on SI
Isolates charging(downstream of HCV-142)
8107-F, 8108-G
Motor operated CIV
Different possible loads on seal water hx?
During SI
Seal return
Excess letdown
CCP recirc
Only CCP recirc
