[AS] - Auxiliary Steam Flashcards
Why do we send [AS] to MSRs?
-steam blanket while the MT is offline
-prevent tube corrosion
[AS]
When would you use [AS] to provide [GS] to the Main Turbine and MFWPs?
Aux Feed
Main Feedwater Pumps
-unit startup
[AS]
What does [AS] provide overspeed testing for?
(2)
Main FW Pumps
‘A’ [AF] Pump
[AS]
[SG] provides steam to [AS] through pressure reducing valves during Normal Ops. What supplies this during shutdown/startup?
[AS] of another operating unit
[AS]
What is the typical pressure for Main Steam and what pressure does it get reduced to for use in [AS] ?
1000-1150 psig
to 250 psig
[AS]
What pressure will [AS] reliefs lift?
275 psig
[AS]
[AS] pressure is reduced again to 50 psig for use by what components?
(3)
[LR]
Gas stripper
BAC
Evaporator
What pressure is [AS] reduced before being sent to MSRs for steam blanketing?
52.3 psig
[AS]
What does RU-7 monitor?
[AS] Condensate Receiver Tank
What does [NH] power in [AS]? What happens if we lose [NH]?
-Condensate Receiver Transfer Pumps
1- [AS] in AB secured until power is restored
2- Gas stripper, Evaporator, and BAC will be OOS
[AS]
What does [NC] do for [AS]?
What happens if we lose [NC]?
[AS] Vent Condenser cooling
-[AS] to AB secured until [NC] is restored
[AS]
[AS] and loss of [SQ] ?
[SQ] Radiation Monitoring System
sample Condensate before sending back to the main condenser
[AS]
If [AS] system condensate drains are contaminated, where are they sent to?
[LR] Liquid Radwaste
[AS]
Why do we establish a steam blanket in the MSRs during a shutdown?
-corrosion inhibition
[AS]
What is the Condensate Receiver volume? Design operating pressure?
335 gallons
50 psig
[AS]
What is the purpose of the [AS] Vent Condenser?
-Condenses steam which would otherwise vent to atmosphere and returns it to the receiver
[AS]
What cools the [AS] Vent Condenser?
(Tube Side)
[NC] Nuclear Cooling Water
[AS]
What is the purpose of the [AS] Condensate Transfer Pump min flow lines?
-Returns 5 gpm to the receiver
-prevents pump from overheating
[AS]
Where is the Condensate Receiver Package located?
AB 51’ 6”
What will happen if RU-7 detects high radioactivity in the condensate?
What must be done when the condition clears?
Condensate will be directed to the [LR] TDS holdup tanks
ASN-RV-11A must be manually reset by lifting the latch lever upward until it engages with the latch.
How do ASN_RV-11A and -11B fail upon a loss of instrument air?
RV-11A fails closed, RV-11B fails open
What is auto feature associated with [AS] supply valves to [LR] BAC, Evap, and gas stripper, AS-PV-331 and -332? What activates it?
-trip shut on a ruptured [AS] line in AB, CST pipe tunnel, or HUT tunnel
-20 pressure switches scattered throughout the building (1.0 +/- 0.1 psig)
Valves manually reset by lifting latch lever
During all modes of operation, [AS] can provide low pressure steam to what equipment?
gas stripper
LR evaporator
BAC
If a unit is receiving [AS] from another unit, where does the condensate go?
-sent to the [CD] receiver package and returned to the main [CD] of the unit supplying the [AS]
What makes up the [AS] condensate receiver package?
receiver tank
vent condenser
2 [AS] condensate transfer pumps
Where does [AS] vent condenser send non condensable gases?
[HA] AB HVAC
Where does the AS condensate from the turbine building drain to?
main condenser
How does the AS system interface with the ED (feedwater heater extraction steam and drain) system?
AS sends aux steam condensate drains to the ED blowdown stack
describe the manual and auto controls of the AS condensate transfer pump.
manual: local three position switch- start, stop and auto
Auto: controlled through alternator and level switches (hi-hi, lo-lo, high and low)
All AS steam is eventually condensed, with one exception. What happens to the steam after it leaves the A aux. feedwater pump turbine?
exhausted to atmosphere
Normally, all units have their AS systems cross-tied, With one unit having ASN-V015 open and the other two have ASN-V014 open. What is the purpose of this?
allows a rapid restoration of turbine GS steam via the cross tie in the event of a MSIS
Define water hammer. What causes it?
Pressure change in a closed system resulting from a change in liquid velocity. Change in liquid momentum exerts an impulse (F*t) on the liquid, and the associated energy change dissipates as a pressure shock wave. This shock wave travels at the speed of sound in the liquid.
rapid throttling of valves, introducing liquid to a voided line, steam/water interfaces where condensing steam may suddenly remove a resistance to flow of either liquid or seam
