SBCS: Steam Bypass Control System Flashcards Preview

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Flashcards in SBCS: Steam Bypass Control System Deck (77)
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1

What is SBCS designed to do?

Prevent unnecessary reactor trips and opening of Pressurizer and SG Safeties.

2

How much of a load rejection can SBCS handle without a RPCB?

57%

3

What valves make up Group X in SBCS?

1001, 1004, 1003, 1006

4

When does Group X Quick Open?

On a Reactor Trip if Tc > 575F
A step change of 15%-20%

5

What valves make up Group Y in SBCS?

1002, 1005, 1007, 1008

6

When does Group Y Quick Open?

A step change of 45%-50%

7

How many SBCS valves does each condenser shell have?

A - 3
B - 2
C - 1
Atmosphere - 2

8

Why the uneven number of SBCS valves to the condenser shells?

To ensure equal shell loading

9

What is the only position the System Mode Selector Switch can be in where SBCS will work?

OPERATE

10

What must be done prior to changing the TLI Selection in the SBCS?

You have to be in EMERGENCY OFF or you have to be in MANUAL on the Master Controller.

11

When changing the position of the System Mode Selector Switch on the SBCS, what must be done?

You have to be in EMERGENCY OFF or a QO may be generated.

12

What is the black needle on the SBCS Master Controller?

The local setpoint generated with the thumbwheel

13

What is the black and white needle on the SBCS Master Controller?

The remote setpoint

14

What is the Modulation signal based on when in AUTO on the SBCS Master Controller?

error between steam header pressure and the pressure setpoint

15

When in MANUAL on the SBCS Master Controller, how is the output controlled?

Via the slide switch

16

What must be done before going to LOCAL on the SBCS Master Controller?

You have to go to Manual or you'll get a QO.

17

If power is lost to the SBCS Master Controller for < 2 seconds, in what mode will it return?

Manual

18

If power is lost to the SBCS Master Controller for > 2 seconds, in what mode will it return?

SBCS shifts to EMERGENCY OFF

19

What SBCS function is not available while in REMOTE/AUTO on the Master Controller?

Quick Open

20

To what does the output on the SBCS Master Controller go when a Quick Open occurs? Why?

83.3%

So that transfer to modulation occurs smoothly

21

What do you want to do before going to LOCAL/AUTO on the SBCS Master Controller?

Input manual permissives to prevent popping SBC valves.

22

When in AUTO, from where do the Individual Controllers get their demand signal?

From the SBCS Master Controller

23

What are the implications of going to MANUAL on an Individual Controller in the SBCS?

It reduces your availability

24

What indicates actual valve position on an Individual Controller in the SBCS?

The red needle

25

When an Individual Valve in the SBCS is placed in OFF on the switch, what happens?

The valve will not open under any circumstances

26

When an Individual Valve in the SBCS is placed in AUTO on the switch, what happens?

The valve will get its permissive signal from the permissive circuit

27

When an Individual Valve in the SBCS is placed in MANUAL on the switch, what happens?

The permissive signal is manually input and energizes the permissive solenoid. White light comes in.

28

How many Individual Valves in SBCS can be given a manual permissive at a time?

one

29

What provides the inputs to the Modulation Circuit for SBCS?

Steam Pressure (PT-1024)
Steam Flow (FT-1011/1012)
Pzr Pressure (PT-100X)

30

What provides the inputs to the Permissive Circuit for SBCS?

Steam Pressure (PT-1027)
Steam Flow (FT-1021/1022)
Pzr Pessure (PT-100Y)