Reactor Auxiliary Cooling

Question 1

What are the RACS SW cooling isolations?

Answer 1

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)

Question 2

What are the RACS pump trips?

Answer 2

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.

Question 3

When do the RACS demins isolate?

Answer 3

High Conductivity
EIAC Start

Question 4

When do the RACS containment supply and returns isolate?

Answer 4

LOCA Level 1 (-129” or 1.68#)
LOP

Question 5

When do the RACS to Recirc seals isolate?

Answer 5

LOCA Level 1 (-129” or 1.68#)

Question 6

What interlock is associated with the HX inlet valve?

Answer 6

Either HX inlet valve must be full open to start the RACS pump

Question 7

If there is a rupture between RACS and SSW where will the leakage go?

Answer 7

SSW

Question 8

What flow rates do the RACS pumps try to maintain?

Answer 8

• 1 pump – 3300 gpm
• > 2 pumps – 5600 gpm

Question 9

What channel provides power to the RACS head tank M/U and what happens when the valve fails?

Answer 9

RACS Head tank M/U fails open on loss of air. Must be manually isolated to prevent overfilling the RACS head tank – ‘A’ Channel

Question 10

What happens when operating RACS in parallel with CW?

Answer 10

This will overfill CW head tank and drain the RACS Head tank.

Question 11

How long do you have to secure systems after RACS is lost?

Answer 11

1. RWCU – 5 min
2. Recirc – 5 min

Question 12

What happens when the RACS flow control valve looses power?

Answer 12

Flow Control Valve fails OPEN on a loss of power, temps will rise.

Question 13

What are the minimum and maximum temperatures for the CRD equipment and what happens when the temperatures are exceeded?

Answer 13

Min-Max operating temperature is 40-95F, beyond 95F, all loads get secured.

Question 14

What are the limitations on RACS when there is no SSW to cool it?

Answer 14

Limited to
1. One CRD pump
2. One Recirc pump
3. Two Cleanup pumps
4. Above 95F, all loads need to be secured.

Question 15

What occurs in RACS when a LOP occurs?

Answer 15

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.

Question 16

What loads are supplied during a LOP?

Answer 16

RACS Supplies the following Loads in lieu of CW during a LOP:
-Drywell Air Coolers
-RR Pump Motor Air Coolers
-DWEDS
-Steam Tunnel Air Coolers

Question 17

What occurs to RACS on a LOCA?

Answer 17

RACS Pump Trip
RACS to Recirc Seals Isolate
RACS Cont. Sup and Rtn Isolate
RACS Sup/Rtn to RW Isolates
SSW Cooling to RACS Isolates
* Power to RACS can be O/R and restored. However, SSW to the HX CANNOT be restored.

Question 18

What does RACS cool in the Rx Building?

Answer 18

RWCU Pumps -Pump Cover, Seal, and Bearing Oil Coolers.
RWCU Non-Regen Heat Exchangers (2).
Rx Bldg Sample Station Coolers.
Recirc Pumps - Motor oil (upper & lower) clr & Seal clr.
CRD Pump Coolers - Thrust Bearing & Gear Box Coolers.
Rx Bldg Equipment Drain Sump Cooler.
Alternate Cooling to Selected Chilled Water Loads:
(DW Air Clr (8), Recirc Motor Air Clr (1/pump), DWEDS (1))
NOTE: Above 3 loads are downstream of the PCIV’s.
Steam Tunnel Air Coolers (2).

Question 19

What does RACS cool in the Aux Building?

Answer 19

Charcoal Compartment Refrigeration (1).
Standby Charcoal Compartment Refrigeration (1).
Glycol Refrigeration Machine (1).
Standby Glycol Refrigeration Machine (1).
Feed Gas Cooler Condensers (2).

Question 20

What does RACS cool in the Turbine Building?

Answer 20

EIAC - intercooler, lube oil cooler and after cooler

Question 21

What is the difference between a LOP and a LOCA with regard to CW?

Answer 21

NORMALLY Supplied CW Loads