CVCS Flashcards
CVCS
STATE the five functions of the Chemical and Volume Control System (CS).
- Maintain the programmed water level in the pressurizer (ensure required inventory in the RCS)
- Maintain the seal water injection flow to the RCP #1 seals
- Control the reactor coolant water chemistry, radioactivity levels and concentration of soluble chemical neutron absorber (boron)
- Provide emergency core cooling (High head portion of Safety Injection)
- Provide a means of filling, draining and pressure testing the RCS
DRAW and LABEL the Chemical and Volume Control System (CS) including major components and the related system flow paths
- normal letdown and charging
- excess letdown
- RHR purification
- ECCS injection and recirculation
STATE the function of the following CS component: Letdown level control valves (LCV-459 & 460)
- Normal letdown isolation valves
- Interlocked with CS-V-145
- Auto Close:
- Low Pressurizer Level ( 17%
- CS-V-145 Full Closed
- Air-operated, fail closed valves
STATE the function of the following CS component: Letdown isolation valve (V-145)
- Interlocked with LCV-459/460 (both valves must be full open and pressurizer level >17% to open)
- Keeps HX pressurized when placing in service or responding to a low pressurizer level/inadvertent LV-459/460 closure
- Interlocked with Containment Isolation valves CS-V-149/150. Either valve “not full open” will auto close CS-V-145 which will prevent the relief valve from lifting
- Air operated, fail closed
STATE the function of the following CS component: Letdown hand control valves (HCV-189 & 190)
drag valves, where pressure is reduced from operating pressure (2235 psig) to 350 psig
STATE the function of the following CS component: Letdown containment isolation valves (CS-V149 & 150)
- V149 is motor operated (IRC)/ V150 is air operated, (ORC) fail closed
- Close on a T (Phase A) Signal and High Energy Line Break (HELB) isolation signal
- Either valve “not full open” will auto close CS-V-145.
STATE the function of the following CS component: Letdown pressure control valve (PCV-131)
• Maintains 350 psig pressure downstream of drag valves to prevent steam flashing
STATE the function of the following CS component: Letdown high temperature divert valve (TCV-129)
- Used to bypass Letdown and BTRS demins to prevent resin damage (> 165 °F).
- Auto divert interlocks: letdown temperature >134 °F or inlet to BTRS demins > 157°F.
- Air operated, 3-way valve controlled from MCB
STATE the function of the following CS component: Letdown divert valves (LCV-112A and LV-112A)
- LCV-112A is an air operated, 3-way divert valve, fails to the VCT and is used when degasifier is not in service
- Used to divert letdown to PDT
- LV-112A is an air operated, 3-way divert valve, fails to the VCT
- Used when degasifier is in service and diverts to BWST
STATE the function of the following CS component: Charging pump suction valves from VCT (LCV-112B and LCV-112C)
- Isolate VCT from CCP suction
* Close on an SI and Lo-Lo VCT Level 5%
STATE the function of the following CS component: Charging pump suction valves from RWST (LCV-112D and LCV-112E)
- Open on low-low VCT level or SI
* Isolate the RWST from the CCP suction
FCV-121
- Controls total pump flow rate (charging + seal injection)
* Pressurizer master level controller controls position of FCV-121 when in auto
HCV-182
Controls seal injection flow rates by controlling the back pressure supply to the seals
STATE the normal values for the following:
L/D flow and pressure
VCT temperature and pressure
Charging pump discharge pressure
Charging header flow
Seal water injection flow and temperature
Seal water return flow
L/D flow and pressure 120 gpm / 2235 psig / 350 psig
VCT temperature and pressure 90 °F/ 25 psig
Charging pump discharge pressure: 2425 psig
Charging header flow 132 gpm
Seal water injection flow and temperature 32 gpm / 120 °F
Seal water return flow 12 gpm
