AS- Auxiliary Steam

Question 1

Why would we send Aux Steam to the MSRs?

Answer 1

To establish a steam blanket while the Main Turbine is offline to prevent tube corrosion

Question 2

Under normal conditions, when would I use AS to provide Gland Sealing steam to the Main Turbine and MFWPs?

Answer 2

During a unit startup

Question 3

The AS system can provide overspeed testing for what components?

Answer 3

Main Feedwater Pumps and ‘A’ AFP

Question 4

Normally, Main Steam provides steam to the AS system through pressure reducing valves. During a shutdown or startup, where else may it be supplied from?

Answer 4

Auxiliary Steam of another operating unit

Question 5

What is the typical Main Steam pressure and what does it get reduced to for use in the AS system?

Answer 5

1000-1150 psig

Reduced to 250 psig

Question 6

At what pressure will the AS reliefs lift?

Answer 6

275 psig

Question 7

AS pressure is further reduced to 50 psig for use by what components?

Answer 7

Gas stripper, BAC, and LRS evaporator

Question 8

At what pressure is AS reduced to be sent to the MSRs for steam blanketing?

Answer 8

52.3 psig

Question 9

What does RU-7 monitor?

Answer 9

AS Condensate Receiver tank

Question 10

What does NH power in the AS system? What happens if we lost NH?

Answer 10

Condensate Receiver Transfer Pumps

AS in Aux Building will have to be secured until power is restored

Gas stripper, LRS evaporator, and BAC will no longer be available to process water for disposal or recycle

Question 11

What does NC do for the AS system? What if we lose NC?

Answer 11

Cools AS systems’ vent condenser

If lost, AS to Aux Building will have to be secured until NC is restored

Question 12

How is AS affected by a loss of Radiation Monitoring System (SQ)?

Answer 12

Condensate will have to be sampled before it can be sent back to the main condenser

Question 13

If AS system condensate drains are contaminated, where are they sent to?

Answer 13

Liquid Radwaste System

Question 14

Why do we establish a steam blanket in the MSRs during a shutdown?

Answer 14

To keep the tubes from being exposed to moisture and oxygen, minimizing corrosion

Question 15

What is the Condensate Receiver volume? Design operating pressure?

Answer 15

335 gallons

50 psig

Question 16

What is the purpose of the AS Vent Condenser?

Answer 16

Condenses steam which would otherwise vent to atmosphere and returns it to the receiver

Question 17

What, for cooling water, flows through the tubes of the AS Vent Condenser?

Answer 17

Nuclear Cooling Water

Question 18

What is the capacity of the AS Condensate Transfer Pumps?

Answer 18

115 gpm

Question 19

What is the purpose of the AS Condensate Transfer Pump minimum flow lines?

Answer 19

Returns approximately 5 gpm to the receiver to prevent pump from overheating

Question 20

What is the maximum operating temperature for the mechanical seals in the AS Condensate Transfer pumps? How does that affect the receiver?

Answer 20

250F

This limits the maximum operating pressure of the receiver to about 15 psig

Question 21

Where is the Condensate Receiver Package located?

Answer 21

51’ 6” of Aux Building

Question 22

What will happen if RU-7 detects high radioactivity in the condensate? What must be done when the condition clears?

Answer 22

ASN-RV-11A will close and -11B will open, directing the condensate from the main condenser/condensate cross-tie to the in-service low TDS holdup tank

If condition clears, ASN-RV-11A must be manually reset by lifting the latch lever upward until it engages with the latch

Question 23

How do ASN_RV-11A and -11B fail upon a loss of instrument air?

Answer 23

RV-11A fails closed, RV-11B fails open

Question 24

What is the automatic feature associated with, AS supply valves to BAC, LRS evap, seal injection HX and gas stripper, AS-PV-331 and -332? What activates it?

Answer 24

They will trip shut on a 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 1.0 +/- 0.1 psig

Valves will have to be manually reset by lifting latch lever

Question 25

During all modes of operation, the AS system can provide low pressure steam to what equipment?

Answer 25

gas stripper

LR evaporator

BAC

Question 26

If a unit is receiving aux. steam from another unit, where does the condensate go?

Answer 26

sent to the condensate receiver package and then returned to the main condenser of the unit supplying aux steam

Question 27

What are the components of the AS condensate receiver package?

Answer 27

receiver tank, vent condenser and two AS condensate transfer pumps

Question 28

Where does the AS vent condenser send non condensable gases?

Answer 28

aux. building hvac

Question 29

Where does the AS condensate from the turbine building drain to?

Answer 29

main condenser

Question 30

How does the AS system interface with the ED (feedwater heater extraction steam and drain) system?

Answer 30

AS sends aux steam condensate drains to the ED blowdown stack

Question 31

describe the manual and auto controls of the AS condensate transfer pump.

Answer 31

manual: local three position switch- start, stop and auto

Auto: controlled through alternator and level switches (hi-hi, lo-lo, high and low)

Question 32

All AS steam is eventually condensed, with one exception. What happens to the steam after it leaves the A aux. feedwater pump turbine?

Answer 32

exhausted to atmosphere

Question 33

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?

Answer 33

allows a rapid restoration of turbine GS steam via the cross tie in the event of a MSIS

Question 34

Define water hammer. What causes it?

Answer 34

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