LOT 202.36 Essential Chilled Water

Question 1

• LOT 202.36 Essential Chilled Water*
• • *

Where is the essential chilled water expansion tank physically located?

Answer 1

• *MAB 26’**
• CCW HX Room*

Pressurized with N₂ (26 - 30 psig) for NPSH

• Still OPERABLE if expansion tank at P_atm
• • *
• _​Note:*
• Unlike level control which is a manual valve, the N₂ pressure control valve is a self-actuated pressure regulator valve.*

Question 2

• LOT 202.36 Essential Chilled Water*
• • *

What system fills the essential chilled water expansion tank?

Answer 2

Demin Water

Filled with manual valve. (+5” - +12”)

Question 3

• LOT 202.36 Essential Chilled Water*
• • *

What AHUs in the FHB are supplied by Essential Chilled Water?

Answer 3

SFP AHU

Containment Sump Isolation Valve AHU

ESF pump cubicles AHU

Question 4

• LOT 202.36 Essential Chilled Water*
• • *

What permissives must be met in order for the essential chillers to sequence onto the ESF DGs?

Answer 4

• *Chill Water Outlet Temp ≥ 38 ˚F**
• Resets at 39 ˚F*
• *Chill Water D/P across evaporator HX ≥ 5 psid**
• 5 psid [5 sec TD] / Reset at 7 psid*

Chill Water pump breaker shut

Question 5

• LOT 202.36 Essential Chilled Water*
• • *

What spaces in the EAB are cooled by Essential Chilled Water?

Answer 5

EAB Main Supply

• *EAB Pen Space**
• Cooled by Emergency MAB AHU located in MAB*

CRE

Question 6

• LOT 202.36 Essential Chilled Water*
• • *

How many trains of essential chilled water is normally in operation?

Answer 6

2 Trains

LCO 3.7.14 Essential Chilled Water Loops requires 3 trains to be OPERABLE in MODES 1 -4.

• Note:*
• Due to 2 trains of EAB HVAC in operation*

Question 7

• LOT 202.36 Essential Chilled Water*
• • *

What cools the essential chillers?

Answer 7

ECW

Question 8

• LOT 202.36 Essential Chilled Water*
• • *

What ECW pond temperature would make the Essential Chilled Water system inoperable?

Answer 8

< 41 ˚F

Per POP02, declare inoperable in MODES 1 - 4.

Question 9

• LOT 202.36 Essential Chilled Water*
• • *

What powers the essential chillers and the essential chilled water pumps?

Answer 9

• Essential Chillers:*
• *E1A / E1B / E1C**
• Essential Chilled Water Pumps:*
• *MCC E1A1 / E1B1 / E1C1**

Question 10

• LOT 202.36 Essential Chilled Water*
• • *

What AHUs in the MAB are supplied by Essential Chilled Water?

Answer 10

Essential Chiller Room

Rx Makeup Water Cubicle

Boric Acid Transfer Pumps Cubicle

CVCS Valves Room

CVCS Pump Room

Radiation Monitoring Room

Question 11

• LOT 202.36 Essential Chilled Water*
• • *

When will the running and standby essential chillers start on a LOOP / SI? (ESF DG Sequencer)

Answer 11

• Standby:*
• *35 sec**
• (Chilled Water Pump / Chiller Oil Pump)*
• *65 sec (30 sec prelube cycle)**
• Essential Chiller*
• Running:*
• *240 sec**
• (Chilled Water Pump / Chiller Oil Pump)*
• *270 sec (30 sec prelube cycle)**
• Essential Chiller*

Running essential chiller must complete 135 sec post lube cycle before it can be restarted on ESF DG sequencer.

Note:
ESF sequencer bypasses the 30 min anti-recycle timer permissive

Question 12

• LOT 202.36 Essential Chilled Water*
• • *

How do the pre-rotation vanes and hot gas bypass work?

Answer 12

• Pre-Rotation Vanes:*
• *Control chill water temp from 10% - 100%**
• *Temp↑ Vanes open**
• *Temp↓ Vanes close**
• Hot Gas Bypass:*
• *When Vanes 10% open control shifted to Hot Gas Bypass**
• *Sends hot gas from condenser to evaporator**
• *Once Hot gas bypass full open control shifted back to vanes**
• *Vanes will then close**

Vanes and hot gas bypass will not move for 4 minutes on startup to prevent oil foaming.