Essential Cooling Water (EW)

Question 1

What ESFAS signals start the Essential Cooling water pump?

Answer 1

SLACCC -
SIAS
LOP
AFAS
CREFAS/CRVIAS/CSAS

Question 2

When will the BOP-ESFAS auto-sequencer start the Essential Cooling water pumps during a SIAS?

Answer 2

20 seconds

Question 3

Which train EW surge tank will close the EW-NC cross tie on a low level?

Answer 3

Train A -
The EW to NC cross-tie valves will automatically close on either of the following signals: SIAS and LO Level in the Surge Tank.
The Control Room Operator has the capability to override the SIAS signal at the handswitch for EWA-UV-65 and EWA-UV-145. There is no capability to override the surge tank LO Level signal.

Question 4

What are the EW radiation monitors?

Answer 4

Ru-2 for EW A
Ru-3 for EW B

Question 5

What is the Design Basis for Essential Cooling Water system?

Answer 5

The required cooling water flow and associated heat transfer capability are compatible with providing the required ESF system cooling water within the maximum design limit of 135° F during a postulated LOCA.

Question 6

What components receive cooling from the Essential Cooling water system?

Answer 6

The EW system supplies cooling to the following components:
* Shutdown Cooling Heat Exchanger
* Essential Chiller
* NC Priority Loads (Backup)
* SFP Heat Exchangers (Backup)

Question 7

What are the Nuclear Cooling Water priority loads?

Answer 7

• RCPs (Seal coolers, HP coolers, Thrust bearing coolers, Motor coolers, and Motor Lube Oil
  Coolers)
• CEDM Normal ACUs
• Normal Chillers
• Nuclear Sample Coolers

Question 8

If Essential Chiller (EC) A is isolated from Essential Cooling Water A, is Essential Cooling (EW) system INOPERABLE?

Answer 8

No
Isolation of the EW System to the Essential Chiller, while rendering the Essential Chiller inoperable, is acceptable and does not impact the OPERABILITY of the EW System. Isolation of the EW System to SDC system heat exchanger is not acceptable and would render both the EW System and the SDC system inoperable.

Question 9

What are the sources of makeup water for the Essential Cooling (EW) system?

Answer 9

Demineralized water (DW) is the normal source of water to the solenoid operated -makeup valves.
Backup make-up water is available from condensate storage and transfer (CT), cooling water holdup (CM), and fire protection (FP) as an emergency source only.

Question 10

What causes a white SEIS alarm for the “A” EW Pump?

Answer 10

• EWA-P01 lockout relaty actuated
• 4160 VAC circuit breaker closing spring NOT charged
• Loss of 125 VDC control power to the 4160 VAC supply breaker