Aux Steam

Question 1

Why should we send aux steam to the MSRs

Answer 1

To establish a steam blanket while the main turbine is offline

Question 2

Under normal conditions when should I use AS to provide GS to MT 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. During a shutdown or startup where else may it be supplied from?

Answer 4

Another unit

Question 5

what is typically main steam pressure and what does it get reduced to for use in the AS system

Answer 5

1000-1150 psig and reduced to 250psig

Question 6

what pressure do the AS reliefs lift?

Answer 6

275 psig

Question 7

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

Answer 7

Gas stripper, BAC, Evaporator

Question 8

What pressure is AS used for steam blanketing in the MSRs?

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 transfer pumps
AS in aux building will be secured until power is restored and Gas stripper, BAC and evaporator cannot process

Question 11

What does NC do for the AS system and what happens if it is lost?

Answer 11

Cools AS vent condenser and AS will need to be secured in the aux building

Question 12

How is AS affected by a loss of rad monitoring?

Answer 12

condensate will need to be sampled before it can be sent to the main condenser

Question 13

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

Answer 13

LRS

Question 14

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

Answer 14

To minimize corrosion and keep the tubes from moisture and oxygen

Question 15

What is the condensate receiver volume and operating pressure?

Answer 15

335 gallons
50 psig

Question 16

What is the purpose of the AS vent condenser?

Answer 16

condenses steam that would otherwise go to atmosphere via vent but instead returns to the receiver

Question 17

What flows thru the vent condenser?

Answer 17

NC

Question 18

What is the capacity of the AS condensate transfer pumps?

Answer 18

115gpm at 155 TDH

Question 19

What is the purpose of the AS condensate transfer pump mini flow lines?

Answer 19

returns 5 gpm to the receiver to prevent pump from overheating

Question 20

what is the max operating temp for the mech seals in the AS CT pumps? how does it affect the receiver?

Answer 20

250F
Limits max operating pressure of the receiver to 15psig

Question 21

where is the condensate receiver package located?

Answer 21

52’ aux building

Question 22

What will happen if RU-7 detects high rad 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 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

Question 23

How do RV-11A and -11B fail upon loss of IA?

Answer 23

11A fails closed
11B fails open

Question 24

What is the automatic feature associated with AS-PV-331 and -332?
What activates it?

Answer 24

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.