Mode 1 to Mode 3

Question 1

What is contained in the scope of 40OP-9ZZ07 Shutdown Mode 1 to Mode 3?

Answer 1

• Reactor trip from 20%
• Reactor trip if unable to maintain 7-12%
• Maintaining 10-12% with Turbine on-line
• Maintaining 7-12% with Turbine NOT on-line

Question 2

Describe the major general steps contained in 6.1, Rx shutdown by opening RTBs.

Answer 2

• Power is 18-22% or a shutdown is in-progress
• Adjust VARS to zero
• PZR boron equalization is in progress
• Only two Charging pumps running
• Trip reactor from B05
• Remove generator core condition monitor from service (AO standing by ahead of time)
• Go to SPTAs

Question 3

How is ASI monitored and controlled during power reduction below 20% in section 6.2?

Answer 3

• ASI is between ± 0.45 on CPC PID 187
  
  • Monitor every 15 minutes
  • Trip Reactor if exceeding ± 0.45 and trending towards Aux Trip setpoint (± 0.5) and Aux trip still possible (rule of 45)
  • When sum of the 3 NIs is < 45%, ASI will change to the canned value (no aux trip)

Question 4

What actions should be taken if the MG < 410 MWe and condenser vacuum is >4” HgA for more than 1 hour or >= 5” HgA?

Answer 4

The reactor must be tripped.

Question 5

How is MFW valve swapover performed once 15% power is approached?

Answer 5

• MFW valve swapover (15%)
  
  • Turbine / reactor power matched
  • SBCVs closed
  • Adjust MFP bias to > 1290 psig discharge pressure
  • Reduce power to 10-12% with CEAs or boration while maintaining Tcold 562.5-563.5°F
  • Once swapover is complete, adjust turbine load to maintain Tcold 564-566°F
  • Isolate Economizer Line Stop valves (< 12%) (due to ECCV leakage)

Question 6

What actions are taken if the MT will be shutdown in 40OP-9ZZ07?

Answer 6

• If Turbine will be shutdown:
  
  • Transfer load to SBCS / reduce load to 65-75 MWe and shutdown the generator
  • Reclose PCBs within 2 hours (breaker life / breakdown of surge capacitors)
  • Stop HDTPs
  • Stabilize 7-12%

Question 7

When is the generator core monitor shutdown and why?

Answer 7

PRIOR to <1000 rpm on the MT. There is not enough air flow to provide sufficient cooling. The generator core condition monitor is removed from service (AO standing by ahead of time) to protect it from overheating.