AOP-24 "S/G Tube Leak"

Question 1

AOP-24 entry conditions

Answer 1

• Primary to Secondary leak rate >= 0.003 gpm in Modes 1 and 2, or 0.05 gpm in Modes 3 and 4
• Adverse trends in any of the following:
  
  • RIA-0631, Off Gas Rad Monitor
  • RIA-0707, S/G Blowdown Process Monitor
  • RIA-2323, Main Steam Safety and Dump Valve Discharge
  • RIA-2324, Main Steam Safety and Dump Valve Discharge
  • RIA-2325, Particulate Stack Monitor Remote Readout
  • RIA-2326, Normal Range Noble Gas Stack Monitor
  • RIA-2327, High Range Noble Gas Stack Monitor

Question 2

AOP-24 automatic actions

Answer 2

• P-55A, Charging Pump, speed rises
• P-55B and/or P-55C, Charging Pumps, start (if tube leakage plus letdown flow exceeds the capacity of P-55A)
• S/G Blowdown Valves close (if RIA-0707, S/G Blowdown Monitor, setpoint is exceeded)

Question 3

AOP-24 reactor trip criteria

Answer 3

• A sustained rise in the CVCS charging rate is needed to maintain PZR level at program level
• PCS makeup requirements exceed those expected for the rate of power reduction in progress
• Radiation monitor response exceeds those expected for the rate of power reduction in progress

Question 4

AOP-24 immediate actions

Answer 4

NONE