Reactor Coolant System

Question 1

What is core bypass flow for?

Answer 1

prevent stagnant areas of water and keeps water in the head below Tsat.

Question 2

What is our normal RCS pressure?

Answer 2

2250 PSIA

Question 3

What is our cold leg temp?

Answer 3

557 degrees F

Question 4

What is our hot leg temp?

Answer 4

617 degrees F

Question 5

What is the motive force for main spray?

Answer 5

RCP’s

Question 6

What is the Steam generator separates the primary and secondary side?

Answer 6

Tube sheet and U-tubes

Question 7

What normally provides heat removal for the RCS system?

Answer 7

Main Steam and FW

Question 8

Where can the primary sampling system get a sample from?

Answer 8

Loop 1 hot leg, surge line, pressurizer steam space

Question 9

What are the three types of CEA’s?

Answer 9

Regulating, part strength, and shutdown

Question 10

How many CEA’s are there?

Answer 10

89

Question 11

What is the 4 spring-loaded pressurizer safety valves setpoint?

Answer 11

2750 psia

Question 12

Why is a fuel rod pressurized with helium

Answer 12

Preclude clad collapse

Improve thermal conductivity

Question 13

Describe the construction of a typical fuel rod

Answer 13

Slightly enriched UO2 pellet
Round wire compression spring
Spacer discs at each end of the fuel column

Question 14

Where do the pressurizer over-pressure relief valves go to on an overpressure?

Answer 14

Reactor Drain Tank

Question 15

What cools the RCP’s?

Answer 15

NCW

Question 16

What does NCW cool on the RCP’s?

Answer 16

• RCP motor air cooler
• RCP motor lube oil cooler
• RCP thrust bearing oil cooler
• RCP seal coolers

Question 17

How many regulating groups are there and how are they designated?

Answer 17

five groups

1,2,3,4,5

Question 18

What components makeup a fuel assembly?

Answer 18

Fuel spacer grids, upper end fitting, hold down plate, lower end fitting, guide tubes, fuel rods

Question 19

Describe a fuel rod?

Answer 19

U02 pellets
Round wire SS compression spring with a spacer disc located at each end of the fuel column all encapsulated in a seal welded tube and pressurized with helium

Question 20

What components makeup a steam generator?

Answer 20

Primary chamber
tube sheet and u-tubes
secondary side shell 
feedwater ring 
economizer
wrapper plate
moisture separators
steam dryers

Question 21

How is oil supplied during normal RCP operation?

Answer 21

Impeller that is keyed to the main drive shaft assy of the pump.

Question 22

Will the lift pump start in auto if the RCP trips?

Answer 22

No, the operator must start the pump. There is no auto start, only the auto stop after 2 minutes of the RCP running

Question 23

What are the three fission barriers?

Answer 23

Fuel Cladding
Reactor Coolant Boundary
Containment

Question 24

How do we regulate RCS pressure?

Answer 24

Pressurizer heaters and Main Spray
Pzr Heaters- (36 of them) Boil water to increase mass of steam in vapor space.
Main Spray- Condense steam in vapor space with subcooled water.

Question 25

How do we regulate pressurizer level?

Answer 25

PZR level control system

Question 26

Explain the main spray valves?

Answer 26

- 100E/F - Start to open- 2275 psia - Full open - 2300 psia

Question 27

Describe the pressurizer?

Answer 27

- Acts as a surge volume to minimize pressure changes - Ensures primary system integrity by preventing over pressurization - Maintains RCS subcooled

Question 28

How is main spray bypass flow rate controlled?

Answer 28

Bypass valves around the main spray bypass valves. Manually adjusted to achieve a flow rate to establish a delta-T between the CL and spray nozzle of the PZR of 70 degrees F.

Question 29

What does IA supply air to in the RCS system?

Answer 29

- Pzr spray valves - Controlled bleedoff containment iso valves - Bleedoff isolation to RDT

Question 30

What are the starting permissives for a RCP?

Answer 30

No motor faults Oil lift flow sufficient NCW flow sufficient RCP seal bleedoff valve fully open

Question 31

RCP automatic trips

Answer 31

Undervoltage Coastdown Overcurrent Speed less then 600 RPM 14 seconds after start

Question 32

Describe the flow path of seal injection through RCP shaft seal assembly.

Answer 32

- 6.6 gpm from CVCS enters HP piping thru jet pump - mixes with 16 gpm from lower journal bearing - 22.6 gpm flows thru HP cooler - Splits. 20 gpm to aux impeller thru journal bearings - Of that 20 gpm, 16 gpm goes back to jet pump - Of that 20 gpm, 4 gpm goes to the RCS - 2.6 of the 22.6 gpm flows thru labyrinth seals - 3 stages (42%/42%/16%) - Most flow back to VCT (of the 2.6 gpm) - Any leakage past vapor seal to RDT