Feedwater Control System

Question 1

What two entries to the steam generators does the Feedwater enter through?

Answer 1

Downcomer region

Economizer region

Question 2

Why is there a downcomer region and an economizer region into the steam generator?

Answer 2

Downcomer: to cools the water that is already doing the heat transfer
Economizer: to provide more heat transfer right before entering the cold leg (greater delta T = greater heat transfer)

Question 3

At what power levels are the downcomer valves providing flow?

Answer 3

Less than 15%: full open

Greater than 50%: 10% flow

Question 4

At what power levels are the economizer valves providing flow?

Answer 4

15%-50%: full open

Greater than 50%: open in accordance to power level

Question 5

Single Element Control of the Feedwater Control System

Answer 5

Measures Steam Generator Level

Used when Power

Question 6

Three Element Control of the Feedwater Control System

Answer 6

Measures Steam Generator Level
measures and compares Steam Flow and Feedwater Flow
When power is > 16.5%

Question 7

What does feedwater flow rate maintain during a reactor trip override?

Answer 7

RCS temperature at 565 degrees F

Tracking when level