Reactor Auxiliary Cooling Flashcards
What are the RACS SW cooling isolations?
Reactor Level 1 (-129”)
Drywell Pressure (1.68#)
RACS Room Flooded (1”)
A Level Switch – Isolates HV-2203 & Gives OHA
B Level Switch – Isolates HV-2204 & Gives OHA
C Level Switch – Isolates In/Out Vlvs & No OHA
*2204 ((B) No close if RSP), 2203 ((A) Can op via keylock)
What are the RACS pump trips?
LOCA Level 1 (-129” or 1.68#) * only A&B trip
Overcurrent/Undervoltage/Bus Pwr Failure
*Only A&B pumps (pwrd from ‘A’ and ‘B’ non-1E busses) will load shed during LOCA (can be O/R). All pumps will be lost during LOP; however, you will be able to bring back A & B since they are powered from 1E.
When do the RACS demins isolate?
High Conductivity
EIAC Start
When do the RACS containment supply and returns isolate?
LOCA Level 1 (-129” or 1.68#)
LOP
When do the RACS to Recirc seals isolate?
LOCA Level 1 (-129” or 1.68#)
What interlock is associated with the HX inlet valve?
Either HX inlet valve must be full open to start the RACS pump
If there is a rupture between RACS and SSW where will the leakage go?
SSW
What flow rates do the RACS pumps try to maintain?
- 1 pump – 3300 gpm
- > 2 pumps – 5600 gpm
What channel provides power to the RACS head tank M/U and what happens when the valve fails?
RACS Head tank M/U fails open on loss of air. Must be manually isolated to prevent overfilling the RACS head tank – ‘A’ Channel
What happens when operating RACS in parallel with CW?
This will overfill CW head tank and drain the RACS Head tank.
How long do you have to secure systems after RACS is lost?
- RWCU – 5 min
- Recirc – 5 min
What happens when the RACS flow control valve looses power?
Flow Control Valve fails OPEN on a loss of power, temps will rise.
What are the minimum and maximum temperatures for the CRD equipment and what happens when the temperatures are exceeded?
Min-Max operating temperature is 40-95F, beyond 95F, all loads get secured.
What are the limitations on RACS when there is no SSW to cool it?
Limited to
1. One CRD pump
2. One Recirc pump
3. Two Cleanup pumps
4. Above 95F, all loads need to be secured.
What occurs in RACS when a LOP occurs?
All RACS pumps will trip as a function of the breaker UV protection on a LOP. The sequencer will then start A and B only.
Loss - RACS to/from RW Isol (Recover when bus restored)
T+13 - Both Loops of CW to the DW isolate.
DW Cooling fans start.
T+55 - Service Water Pump Starts.
T+85 - Both HX Inlet Valves Open.
A&B RACS Pumps Start.
RACS Supply to DW Opens.
