AOP-28 "PZR Pressure Control Malfunctions"

Question 1

AOP-28 entry conditions

Answer 1

• EK-0753 “Pressurizer Pressure Off Normal HI-LO” (HI - 2110 psia, LO - 1975 psia)
• EK-0754 “Pressurizer Pressure Off Normal HI-LO” (HI - 2110 psia, LO - 1975 psia)
• EK-1373 “SV and/or PORV Open”
• Charging or Letdown malfunctions during solid plant operations

Question 2

AOP-28 automatic actions

Answer 2

Possible reactor trip

Question 3

AOP-28 reactor trip criteria

Answer 3

Either Spray Valve failed open and PZR pressure not being maintained

Question 4

AOP-28 equipment trip criteria

Answer 4

• If CV-1057, Pressurizer Spray Valve failed open, then trip P-50A and P-50B. If Pressurizer pressure not being maintained, then also trip P-50D
• If CV-1059, Pressurizer Spray Valve failed open, then trip P-50C and P-50D. If Pressurizer pressure not being maintained, then also trip P-50A
• If PZR pressure < 235 psia for > 1 minute or < 200 psia for any amount of time, then trip all operating PCPs

Question 5

AOP-28 immediate actions

Answer 5

NONE