AOP-28, Pressurizer Pressure Control Malfunctions

Question 1

What are the entry conditions for AOP-28, Pressurizer Pressure Control Malfunctions?

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 System malfunctions during solid plant operation

Question 2

What are the automatic actions of AOP-28, Pressurizer Pressure Control Malfunctions?

Answer 2

Possible reactor trip on TM/LP.

Question 3

What are the trip criteria (reactor/equipment) of AOP-28, Pressurizer Pressure Control Malfunctions?

Answer 3

Reactor Trip

• Either Pressurizer Spray Valve failed open AND Pressurizer pressure not being maintained.

Equipment Trip

• CV-1057 Pressurizer Spray Valve failed open.

Trip P-50A and P-50B, PCPs.

Pressurizer pressure not being maintained. Trip P-50D, PCP.

• CV-1059 Pressurizer Spray Valve failed open.

Trip P-50C and P-50D, PCPs.
Pressurizer pressure not being maintained. Trip P-50A, PCP.

• Operating PCPs
• Pressurizer pressure less than 235 psia for greater than 1 minute, on PI-0104,
• Narrow Range Pressurizer Pressure Ind.
• Pressurizer pressure less than 200 psia on PI-0104, Narrow Range Pressurizer Pressure Ind.

Question 4

What are the immediate actions of AOP-28, Pressurizer Pressure Control Malfunctions?

Answer 4

None

Question 5

What are the three main branching areas of AOP-28, Pressurizer Pressure Control Malfunctions?

Answer 5

• Pressurizer Pressure Control Malfunctions
• Solid Plant Control (Letdown Pressure Control)
• LTOP System Actuation

Question 6

What pressurizer heaters are fed from D-bus?

Answer 6

Group 2 - 75KW

Group 3 - 300KW

Group 4 - 375KW

Question 7

What is the 2-hour load limit for the 1-2 EDG?

Answer 7

2750 KW

Question 8

Why would a containment entry be required for AOP-28, Pressurizer Pressure Control Malfunctions?

Answer 8

On pressurizer spray valve failed open and heaters not keeping up, you trip the reactor.

Post trip you trip P-50A and P-50B. (P-50C/D)

If that doesn’t allow heater to maintain, you trip P-50D (P-50A).

You may need to perform an entry to isolate spray valves manually.

Question 9

How does shutdown margin relate to AOP-28, Pressurizer Pressure Control Malfunctions?

Answer 9

You may need to establish shutdown margin per EM-04-08 “Shutdown Margin Requirements” or COLR section 2.1 “Shutdown Margin”

Question 10

If it is a letdown pressure control issue, what might you do?

Answer 10

Manually operate PIC-0202, Intermediate Pressure Controller.

Alternate Backpressure Regulating Valve CV-2012 or CV-2122

Question 11

How many starts can you perform on a tripped charging pump?

Answer 11

One Attempt

Question 12

When do you trip primary coolant pumps for low pressure?

Answer 12

Less than 235 psia, on PI-0104, Narrow Range Pressurizer Pressure Ind, for more than 1 minute

Question 13

When does LTOP alarm for no protection?

Answer 13

EK-0759, “No PCS Protection Channel A”

EK-0765, “No PCS Protection Channel B”

at 460F on a Tc

Question 14

What are the LTOP trip setpoints?

Answer 14

Normal per LTOP Curve with pre-trip at 50-psi before set-point.

Shutdown Cooling

Trip 310 psia

Pre-trip 265 psia