EW

Question 1

What is the purpose of EW

Answer 1

• Support normal/ emergency S/D’s
• Reject heat to ESP’s
• Intermediate barrier RCS - ESP’s
• Backup cooling for SFP
• Backup cooling NC priority loads
  - RCP’s
  - CEDM Normal ACU’s
  - Normal Chillers
  - Nuclear Sample coolers

Question 2

What is the purpose of EW

Answer 2

• Support normal/ emergency S/D’s
• Reject heat to ESP’s
• Intermediate barrier RCS - ESP’s
• Backup cooling for SFP
• Backup cooling NC priority loads
  - RCP’s
  - CEDM Normal ACU’s
  - Normal Chillers
  - Nuclear Sample coolers

Question 3

How is leakage into or from EW detected

Answer 3

• Hi/Lo surge tank levels
• Rad monitor
• Each system served is monitored

Question 4

What does EW Cool

Answer 4

• SDC HX
• EC Condenser
• SFP backup
• NC priority loads Backup

Question 5

How does EW act as an intermediate system?

Answer 5

EW pressure AT THE EW HX is less than SP press

Question 6

How is NPSH for the EW pump accomplished

Answer 6

• The pump is below the surge tank

- N2 cover gas is for oxygen control NOT NPSH

Question 7

What will Auto start EW?

Answer 7

SLACCC

• SIAS
• LOP
• AFAS
• CSAS
• CREFAS
• CRVIAS

Question 8

What will Auto Stop EW

Answer 8

• Load Shed

- Brkr Trip

Question 9

When does EW Surge tank makeup normal come in

Answer 9

Open - 22”

Close - 26”

Question 10

What are the EW surge tank Hi/Lo levels

Answer 10

Hi - 50” Alarm
Lo - 18” Alarm
LO - 17” A Train x-conn auto closes
LoLo - 14” Makeup isolates

Question 11

What is the Refrigerant Head Pressure Control Vlv and what does it help with

Answer 11

• It is a pressure controlled bypass vlv for the EC
  Condenser
• Helps prevent stacking by bypassing the condenser
  to prevent cooling EC refrigerant too much

Question 12

What is the MOST limiting postulated EW condition

Answer 12

17% degraded EW pump while concurrently aligned to SFP

Question 13

What are the NC priority loads

Answer 13

• RCP
  
  • Seal coolers
  • HP coolers
  • Thrust Brng coolers
  • Motor Coolers
  • Motor lube oil coolers
• CEDM Normal ACU
• Normal Chillers
• Nuc Sample Coolers

Question 14

What additional IN FIELD action is required when EW is aligned to NC Priority loads

Answer 14

Throttle SDC HX until RCP NC Flow alarms clear

Question 15

How is NC Restored to NC Priority loads after being supplied by EW

Answer 15

• EW must be secured to NC loads

- This will temporarily secure cooling flow again

Question 16

What is the most limiting component for supplying cooling flow to NC Priority loads

Answer 16

• RCP’s
• 10 minutes with seal injection
• 3 minutes without seal injection

Question 17

What is required to restore EW to “Operable” after supplying SFP cooling

Answer 17

a Flow Balance must be performed

Question 18

What Auto Features do the Train A EW - NC x-connect vlvs have

Answer 18

Auto close on:

• SIAS
• Lo Surge tank level 17”

SIAS can be overridden to reopen, Lo level CANNOT

Question 19

What is required for EW to be “Operable”

Answer 19

Modes 1-4
2 Trains of EW Shall be operable

2 trains inop: 1 HOUR
- Restore at least 1 train

Question 20

What Special Feature is required by TLCO for MOV thermal overload protection

Answer 20

TLCO 3.8.102 requires the thermal overload for MOV’s on safety related equipment to be bypassable to ensure safety functions are performed

Question 21

What is the effect of isolating the SDC HX

Answer 21

Isolating EW to the SDC HX inops the SDC HX and EW