GA: Service Gases Flashcards
What is the purpose of the 6 N2 storage bottles out by the N2 Skid?
They increase the operating time of the ADVs to 16 hours during a Station Blackout.
How is the High Pressure N2 Header pressure maintained?
With 2 PCVs
One set at 650 psig with a backup set a 630 psig
When will the high pressure alarm for the H2 header announce in the Control Room?
110 psig
Where do we send H2 in the plant?
To the Main Generator
To the VCT
What will trip the N2 Pumps?
Cavitation
High Discharge Pressure - 2400#
Low Vapor Temperature - < -20 F
Low Storage Tank Level - 25”
When will the HP N2 Header alarm in the Control Room?
On High Pressure at 690 psig
How long will the HP N2 Storage Cylinders supply the header?
They are designed for 7 days
When will the low pressure alarm for the H2 storage banks announce in the Control Room?
200 psig
Can the High Pressure N2 Header supply the Low Pressure N2 Header?
Yes, via PV-41
Do the N2 Pumps supply the Low Pressure N2 Header?
No
What happens when a N2 pump first starts?
It goes through a 15 minute cool down cycle
Liquid N2 flows into the pump
When will the HP N2 cylinders alarm on low pressure in the Control Room?
750 psig on either bank
How is the H2 header pressure maintained?
With 2 PCVs
One set at 105 psig with a backup set a 95 psig
Describe how the N2 Pumps maintain HP N2 cylinder pressure.
Positive displacement pump starts when pressure in the cylinders reaches 1400 psig. The pump will automatically stop when pressure in the tanks reaches 2100 psig.
What is the power supply to the N2 Pumps?
NH
NHN-M30
What is the power supply to the N2 Containment Isolation Valves?
PKA
When will the standby N2 pump start?
It won’t because it has its local disconnect open
What does N2 supply in Containment?
The SITs
The RDT
How is the Low Pressure N2 Header pressure maintained?
With 2 PCVs
One set at 115 psig with a backup set a 110 psig
Are the solenoid operated N2 Containment Isolation Valves inside Containment or outside?
Outside. The lines have check valves inside Containment
What is the administrative limit for H2 Storage Bank pressure?
300 psig
How are the HP N2 storage cylinders arranged?
Total of 8 cylinders
Two banks of 4
Each bank has a PCV
Banks are isolated from one another
What will cause the N2 Containment Isolation Valves (GAA-UV-1 and GAA-UV-2) to close automatically?
CIAS
Describe the High Pressure N2 flowpath.
From the N2 Storage Tank, to one of two positive displacement pumps, to the HP vaporizer, to the 8 storage cylinders, to the HP N2 header.
