Week 2: Reactor Coolant Pumps

Question 1

What is the overall purpose of the Reactor Coolant Pumps?

Answer 1

To circulate water through the RCS, thereby transporting heat from the fuel assemblies to the SGs
To heat up the RCS during startup

Question 2

What are the 3 sections of the RCPs?

Answer 2

Motor
Seal
Hydraulics

Question 3

What components are contained within the motor section of the RCP?

Answer 3

Upper/Lower guide bearing
Flywheel
Motor Stator
Thrust Bearing
Spool Piece

Question 4

What components are contained within the seal section of the RCP?

Answer 4

Standpipe
Seals #1, #2, and #3

Question 5

What components are contained within the hydraulic section of the RCP?

Answer 5

Impeller
Thermal Barrier/Thermal Heat Exchanger
Pump Radial Bearing

Question 6

Describe the #1 Seal type, leakoff rate, and pressure drop.

Answer 6

Film riding seal
Leakoff rate of 3 gpm to the VCT outlet
2250 -> 50 psig

Question 7

Describe the #2 Seal type, leakoff rate, and pressure drop.

Answer 7

Face type rubbing seal
Leakoff rate of 3 gph to the RCDT
50 -> 3 psig

Question 8

Describe the #3 Seal type, leakoff rate, and pressure drop.

Answer 8

Face-type rubbing seal with a double dam
Leakoff rate of 400 cc/hr to Containment Sump, 400 cc/hr to #2 seal leakoff line
3 -> Atmosphere

Question 9

Describe the RCP standpipe.

Answer 9

A section of vertical piping above the #3 seal that supplies 800 cc/hr of clean water to the #3 seal and provides 3 psig of backpressure.

Question 10

What is the required amount of oil lift pressure to be achieved before starting an RCP?

Answer 10

550 psig

Question 11

Can an RCP still be operated when seal injection has been lost?

Answer 11

Yes; RCS coolant will flow through the seal at 3 gpm, cooled by the thermal barrier heat exchanger (cooled by CCW).