Reactor Coolant System

Question 1

What size outsurge is the pressurizer sized for?

Answer 1

Provide enough water volume to prevent pressurizer heaters from being uncovered by the outsurge following a step load decrease of 10% from 25% to 15% power or a 5%/min ramp decrease from 100% to 15% power.

Question 2

What are the RCP temperature limits for operation?

Answer 2

To prevent “lift”, operation of RCPs is limited to 3 or less when temperature is below 500oF. For P-T concerns, only two (2) RCPs are allowed below 200oF.

Question 3

What are the starting criteria for an RCP?

Answer 3

BONE -
(B) Seal Bleed-off valve fully open
(O) Lift Oil
(N) NC Flow is sufficient
(E) No electrical fault

Question 4

What is the Tech Spec Safety Limit for Reactor Coolant System Pressure?

Answer 4

2750 psia (Tech Spec 2.1.2)
(design pressure is 2500)

Question 5

At what pressure will the Pressurizer Safety valves lift? Where do they discharge to?

Answer 5

2475 psia (Tech Spec 3.4.10 Modes 1-3 TS 3.4.11 Mode 4)
Discharge to Reactor Drain Tank (in Containment)

Question 6

What are the power and control power supplies for the Reactor Coolant Pumps?

Answer 6

NAN-S01/S02
control power from NKN-D44 (located on NKN-M46)

Question 7

What does the anti-reverse rotation device on the RCP do?

Answer 7

Stops a pump when it reaches a zero speed as it decelerates from running speed while
other pumps continue to operate.

Will withstand reverse torque in case of reversed power leads or during accident conditions.

Question 8

What is the interlock to close an RCP bleedoff valve from the Control Room?

Answer 8

The RCP breaker must be open

• Controlled bypass flow (seal bleedoff) may be isolated for each pump.
  o Seal Bleedoff Isolation Valves are interlocked with running RCPs.
  o Will NOT close if associated RCP is running.

Question 9

How do the RCP Lift Oil Pump handswitches operate?

Answer 9

Lift Oil Pump (NHN):
* Manual Start - will run until RCP started (have to hold in start if pump is already running)
* Auto Starts - when you secure a RCP (must be manually stopped)
* Auto Stops - After 2 min once the RCP is running

Question 10

What are the vent paths for the reactor vessel head? What type of valves are used?

Answer 10

Head / PZR Vents
* SOVs flow to RDT or CTMT

Question 11

What does High Seal Bleedoff header pressure indicate?

Answer 11

Failed RCP Seal

Question 12

What position do CHN-UV-540 and CHN-UV-560 go to when RDT pressure reaches 10 psig?

Answer 12

RDT vent to waste gas header valve CHN-UV-540 will close

CHN-UV-560 will open if closed