Ice condenser Flashcards
What is the Primary function of the ice condenser?
to limit peak pressure in containment during a DBA, LOCA, Steam line break.
What ensures that the steam will go through the ice condenser?
All high energy sources are in lower containment and there is a divider barrier that separates lower containment from upper containment.
What is the flow path of steam during a DBA, LOCA, Steam line break?
In through the lower deck doors, through the turning vains, up through the ice bed through the intermediate deck doors through the upper deck doors in to upper containment. The CEQ fans take suction from upper containment and discharge back into lower containment.
What is the required Boron concentration for the ice?
1800 to 2300 ppm.
What is sublimation?
The process by which a solid (like ice) passes to a vapor state without first becoming a liquid. Two problems caused by sublimation Frost build up Loss of water contents
What is the flow path of the ice condencer AHU?
Suction from upper plenum.
All air handlers discharge into common air distribution header (duct) next to ice.
Circulated air returns to upper plenum through air distribution header (duct) next to contament wall.
The motive force for air flow through the ice condenser compartment is the DT of cold air and warm air.
What are the three modes of opperatio for ice condencer AHU?
Running AHU
AHU In Defrost (4, 8, or 12 AHUs in defrost at a time.40 minutes defrost)
5 minutes off (Both Lights off)
5 minute cooldown (ALL run)
Next Group cycles on.
What is the reasion glycol pumps 1,2,3 and 4,5,6 sould be operated in groups?
Because the auto function only looks at the pumps in that group. ie if pump 1 is in run and pump 5 is in auto and both are aligned to the same unit if pump 1 fails pump 5 will not auto start beause it is looking at pump 4 and 6.
What will automaticly close VSO-20 ,21 and VCR 10,20?
expansion tank Lo-Lo level.
Per procedure where must people be stationed when you are filling the glycol expansion tank?
Co-ordination and communication between personnel at the fill or drain area, the glycol expansion tank, Ice Condenser Refrigeration Sub-panel and the Control Room must be developed prior to any fill or drain evolutions starting
What is the purpose of sodium Tetraborate?
Sodium acts to remove radioactive iodine from the steam leaving the reactor coolant system.
Boron acts as a neutron absorber, and thus aids in maintaining the reactor shutdown.
