Primary Flashcards
Loop 1 starting at RCP
CL Narrow Tcold PZR spray Accum / RHR / SI injection Normal CVCS charging HL RHR suction / SI injection Narrow Thot x 3 IL Flow
Loop 2 (start at RCP)
CL Narrow Tcold PZR spray Accum / RHR / SI HL RHR injection Narrow Thot x 3 IL Flow
Loop 3 (start at RCP)
CL Narrow Tcold Accum / RHR / SI HL RHR injection Narrow Thot x 3 IL Flow Normal CVCS letdown
Loop 4 (start at RCP)
CL Narrow Tcold Alternate CVCS charging Accum / RHR / SI HL Narrow Thot x 3 PZR surge RHR suction SI injection IL Excess letdown
Where does the PZR connect?
Loop 1 spray line
Loop 2 spray line
Loop 4 surge line
Where does the CVCS connect?
Loop 1 normal charging
Loop 3 normal letdown
Loop 4 alternate charging
Loop 4 excess letdown
Pros / cons of constant Tavg program
+ constant volume (minimize PZR)
+ smaller MTC impacts
- large steam pressure variations
Pros / cons of constant Psteam
+ turbine simpler
- Thot too high; low DNB margin
- Large PZR
- Large MTC impacts
CVCS functions
RCS inventory (PZR level) RCP seal injection Chemistry High head SIS flow Fill /drain RCS
List the CVCS heat exchangers and what cools them
Regen - flow returning to the RCS
Letdown - CCW
Seal - CCW
Excess letdown - CCW
PZR level required to open letdown
17%
Why is letdown limited to 120 gpm?
Protect the demins
What should be isolated if letdown is isolated?
What should be maintained?
Charging
Seal injection
Where does water go if the VCT gets too full?
Holdup tank
What happens if the VCT gets too low?
CCP suction shifts to RWST
What is the primary sign of a RCS leak?
Increased auto-makeup to the VCT
CCP functions
PZR level control
Seal injection
High head SI
What controls CCP flow? What happens if operator adjusts seal flow?
Automatic PZR level control
The system will automatically compensate for operator adjustment to split between PZR and seals
What happens to CVCS on SIS?
Letdown isolation closes
CCPs align to RWST
How does PPZ P respond during a level transient?
P follows level, i.e., increasing level causes increasing P
CVCS flow rate breakdown
75 letdown CCP 32 to RCPs (8 per pump) 20 returns to RCS (5 per pump) 12 returns to CVCS (3 per pump) Total CCP = 32 + (75 - 20) = 87
Excess letdown flow breakdown
20 gpm
For use when normal letdown is isolated
Allows seal injection
CCP flow of 32
Purpose of bank overlap
Create a more even DRW
Purpose of RILs
Maintain SDM
Limit REJ
Maintain acceptable peaking
RIL alarms and responses
Lo - 10 steps above, borate
Lo-lo - At/below, emergency borate
RMU modes and where they discharge
Auto - CCP suction Dilute - VCT spray Alt dilute - VCT spray and CCP suction Borate - CCP suction Emergency - CCP suction
Does increase RMU flow increase rate of boration / dilution?
No since PZR level controller doesn’t change CCP flow. This will change the VCT level.
What is the difference between a leak and a LOCA?
Whether or not the CCPs can keep up
What are the options for responding to a RCS leak?
Within TS: start trending
Outside TS:
- if within 1 CCP, controlled shutdown
- beyond 1 CCP, trip and initiate SI
