Redundant Reactivity Control Sys (RRCS)

Question 1

What is the DIV I Power Supply for RRCS?

Answer 1

DIV I, Channel A: AC/DC (UPS2A/C & BYSSWG002)
DIV I, Channel B: DC (BYSSWG002)

Question 2

What is the DIV II Power Supply for RRCS?

Answer 2

DIV II, Channel A: AC/DC (UPS2B/D & BYSSWG002)
DIV II, Channel B: DC (BYSSWG002)

Question 3

In regard to RRCS, what prevents the potential consequences of an Anticipated Transient Without SCRAM (ATWS)?

Answer 3

ARI (Alternate Rod Insertion)

Question 4

In regard to RRCS, what mitigates the potential consequences of an Anticipated Transient Without SCRAM (ATWS)?

Answer 4

1. Recirc Pump Transfer/Trip
2. LF-MG Trip
3. FW Runback (LV10s & 55s close and Min Flow vlvs open)
4. SLC System

Question 5

What is the High Pressure RRCS ATWS sequence?

Answer 5

T=0 Hi Pressure - 1065psig
- ARI initiates
- RCS Pumps fast spd trips
- RCS pumps downshift to slow on LFMG
T=25
- If APRMs are not downscale THEN:
- RCS LFMG trips (RCS pump trip)
- FW level control Vlv runback & min flow vlvs open.
T=30
- ARI ready to reset
- ARI Seal-IN drops out
T=50
Control of FW lvl returned to Operator & min flow vlvs return to normal
T=98
- 10 min timer starts for reset
- SLS initiates, WCS isolates

Question 6

What is the Low Level RRCS ATWS sequence?

Answer 6

T=0 L2 108.8”
- ARI initiates
- RCS pumps trip OFF
T=30
- ARI ready to reset
- ARI Seal-IN drops out
T=98 (L2 still in) timer keeps timing even if L2 clears.
- 10 min timer starts for reset
- SLS initiates, WCS isolates

Question 7

What happens to the FWC valves if they are locked up and a High Pressure RRCS initiates?

Answer 7

The valves will still runback even if they are locked up. The runback will override the lockup.

Question 8

What happens to RRCS on a loss of AC power?

Answer 8

RRCS will work without AC power. MUST have DC power.

Question 9

What is the Manual Initiation RRCS ATWS sequence?

Answer 9

T=0 Arm & Depress
- ARI initiates
T=30
- ARI ready to reset
- ARI Seal-IN drops out
T=98 (APRMs not downscale OR INOP)
- 10 min timer starts for reset
- SLS initiates, WCS isolates

Question 10

What APRMs are tied to what RRCS Channels?

Answer 10

APRM Chart
1 2 1A
3 4 1B
2A 2B