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Flashcards in Steam Dump System Deck (14):
1

What is the purpose of the steam dump system?

Permits the plant to sustain a reactor trip at 100% power with out lifting the steam generator safeties.
Permits the plant to sustain a 50% load rejection with out causing a reactor trip. (40% dumps 10% rods).

2

How many steam dumps are there in each unit?

9
Three groups of 3.

3

Unit 1 is running @ 100% power, all components are performing normally.
1 - If the unit suffers a 25% load rejection, how does the system respond?
2 - which control mode are we in?

1 - group 1 and group 2 dump valves would be available and open.
2 - T-ave load rejection controller.

4

Unit 2 is running at 100% power, all components are performing normally.
1 - If the turbine trips how does the system respond?
2 - which control mode are we in?

1 - You would have groups one and two steam dumps available.
2 - You would be on the turbine trip controller.

5

What arms conditional C7A for steam dumps? And what groups does this effect?

A load reject of 10% or greater.
Only groups 1 and 2.

6

What arms conditional C8 for steam dumps? And how does it effect the different groups?

To arm C8 you need all 4 turbine stop valves closed and 2 of 3 EHC pressure switches below 800 psig. This will arm groups 1 and 2 and block group 3.

7

What arms conditional C7B and which groups are effected?

A load reject of 30% or greater. This only effects group three and makes it available.

8

What do you need to arm Conditional C9? And what groups does it effect?

1 circ water pump
Crid #2
All three condensers @ 20.6"Hg.
This effects all three groups.

9

What arms Permissive P12 for steam dumps and what groups does it effect?

You must be greater than 541*f on 3 of 4 RCS loops. This effects all three groups.
***you can place the control selector switch to "bypass interlock" this bypasses the P12 for group 1 only.

10

How does group 1 steam dump valves move?

One at a time.

11

How do groups 2 and 3 steam dump valves move?

All valves in that group move simultaneously.

12

When would you have the most steam dump valves open?

A load rejection of 30% or greater. You would have all three groups open (9 valves)

13

What does the turbine trip controller look at?

Aucioneered T Avg - T no load

14

What does the load rejection controller look at?

Auctioneered T-avg - T ref.