COLSS

Question 1

How does COLSS calculate NKBDELT?

Answer 1

Primary pressure
Hot leg temperature
Volumetric and Mass flow rates:
- Tcold
- RCP D/P (RCP Speed)
- Pressurizer pressure

Question 2

How does the Power Limit Margin indicator choose what to display?

Answer 2

4 digit red LED indicator on board 4
Displays the margin to the most restrictive power limit
Smoothed plant power is compared to license power, DNBR POL, and LPD POL
Most restrictive value is displayed

Question 3

What is the effect on a VOPT actuation if a heat balance calculation resulted in actual feed flow to be higher than indicated feed flow?

What is the effect on indicated power if blowdown is secured but you haven’t updated the constants?

Answer 3

It will become less conservative (trip at a higher actual power)

Question 4

Describe how we get JSCALOR

Answer 4

1. Calculate a Secondary Calorimetric: (h stm)(FW flow - BD flow) + (h BD)BD flow - (h FW)FW flow
   This calculation will give us BSCRAW
2. Filtered to smooth oscillations to produce JSCALOR

FW Flow
FW Temp
Steam Flow = FW flow - BD flow
Steam Pressure - gives us h stm
BD flow is entered as a constant in the PC and CMC