Mode 1 to Mode 3

Question 1

What protects the plant in event of uncontrolled CEA withdrawal in Mode 3?

Answer 1

CPC trips available
Maintain boron > Hot Zero Power minimums per core data book

NOTE: Applies from time RTSG breakers closed until shutdown CEA’s are fully withdrawn

Question 2

Why do we prefer to shutdown the reactor by going to 20% and then TRIP?

Answer 2

Avoids potential uncontrolled transients due to power reduction thru swapover

Question 3

When must CEDMCS be taken out of Auto Sequential mode?

Answer 3

If power will be lowered to 2-4% power

Question 4

During power reductions…What should be maintained on the auto controlled SBCV?

Answer 4

At least 10% open by throttling closed on any SBCV in Manual.

Question 5

What is modulated at LOW power levels to maintain RCS temperatures?

Answer 5

Main Turbine Stop Valve before seat drain valves

Question 6

Before Mode 3, what must Boron concentration be maintained at?

Answer 6

SDM concentrations

Question 7

When would we report an abnormal condition to GE (Turbine manufacturer)?

Answer 7

Any thrust bearing temp > 180F.
Any sudden increase in metal temp 10F or greater above initial reference temp

NOTE: No Ops allowed when thrust bearing is > 190F

Question 8

What is the MT vibration trip criteria for “Filtered Journal Bearing Vibration”?

Answer 8

> 10 mils (and abrupt trend towards 12 mils)

>10mils (and slow increase to 12 over 15 minutes)