Aux Steam Flashcards
Why should we send aux steam to the MSRs
To establish a steam blanket while the main turbine is offline
Under normal conditions when should I use AS to provide GS to MT and MFWPs?
During a unit startup
The AS system can provide overspeed testing for what components?
Main feedwater pumps and ‘A’ AFP
Normally, main steam provides steam to the AS system. During a shutdown or startup where else may it be supplied from?
Another unit
what is typically main steam pressure and what does it get reduced to for use in the AS system
1000-1150 psig and reduced to 250psig
what pressure do the AS reliefs lift?
275 psig
AS pressure is further reduced to 50psig for use in what components?
Gas stripper, BAC, Evaporator
What pressure is AS used for steam blanketing in the MSRs?
52.3 psig
What does RU-7 monitor?
AS condensate receiver tank
What does NH power in the AS system? what happens if we lost NH?
Condensate transfer pumps
AS in aux building will be secured until power is restored and Gas stripper, BAC and evaporator cannot process
What does NC do for the AS system and what happens if it is lost?
Cools AS vent condenser and AS will need to be secured in the aux building
How is AS affected by a loss of rad monitoring?
condensate will need to be sampled before it can be sent to the main condenser
If AS system condensate drains are contaminated where are they sent?
LRS
Why do we establish steam blanket in the MSRs during shutdown?
To minimize corrosion and keep the tubes from moisture and oxygen
What is the condensate receiver volume and operating pressure?
335 gallons
50 psig
What is the purpose of the AS vent condenser?
condenses steam that would otherwise go to atmosphere via vent but instead returns to the receiver
What flows thru the vent condenser?
NC
What is the capacity of the AS condensate transfer pumps?
115gpm at 155 TDH
What is the purpose of the AS condensate transfer pump mini flow lines?
returns 5 gpm to the receiver to prevent pump from overheating
what is the max operating temp for the mech seals in the AS CT pumps? how does it affect the receiver?
250F
Limits max operating pressure of the receiver to 15psig
where is the condensate receiver package located?
52’ aux building
What will happen if RU-7 detects high rad in the condensate? What must be done when the condition clears?
ASN-RV-11A will close and 11B will open directing the condensate to the inservice low TDS holdup tank.
if condition clears the 11A must be manually reset by lifting the latch lever upward until it engages the latch
How do RV-11A and -11B fail upon loss of IA?
11A fails closed
11B fails open
What is the automatic feature associated with AS-PV-331 and -332?
What activates it?
They will trip shut on ruptured AS line in the aux building, CST pipe tunnel or HUT tunnel.
Activated by any of the 20 pressure switches scattered throughout the building as indicated by the 1+- .1 psig.
Valves will have to manually reset by lifting the latch lever.
