RCPs

Question 1

What are the RCP trips?

Answer 1

• Phase Differential
• Overcurrent
• Overload
• Manual trip when #1 seal outlet temp > 185°F

Question 2

What are the RCP interlocks?

Answer 2

• Bearing Lift Pump Motor Starter Closed

- Bearing Lift Oil # @ 510#

Question 3

What are the RCP power sources?

Answer 3

• B #1 RCP
• C #2 RCP
• D #3 RCP
• A #4 RCP

Question 4

How much heat is added to the RCS by the RCPs?

Answer 4

• 14 MW of heat added to RCS

Question 5

What does the Flywheel do on the RCP?

Answer 5

• helps remove decay heat immediately after trip ***

- increases pump inertia which causes a longer coast down time to help prevent DNB

Question 6

What is the seal injection flowpath of the RCPs?

Answer 6

1. Seal water enters below Radial Bearing and #1 Seal (Normally 8 gpm per RCP)
2. 5 gpm flows down RCP shaft into the RCS
3. 3 gpm flows up thru #1 seal **
4. 3 gph flow up thru #2 seal **
5. 100 cc/hr flows up thru #3 seal **

Question 7

What is the seal return flow path?

Answer 7

• # 1 Seal - Seal Water hx to CCP suction (or VCT) **
• # 2 Seal - RCP Standpipe and to the RCDT.
• # 3 Seal - Outlet of RCDT

Question 8

What are the purpose of the labyrinth seals?

Answer 8

• Minimize thermal barrier heat exchanger bypass flow

- Minimizes RCS leakage to the seal package on a failure of the seals

Question 9

What is the purpose of the Anti-Rotation device (Ratchet Plate)

Answer 9

• Minimize reverse flow through an idle pump

- Lowers starting current when starting RCP with one RCPs already running

Question 10

Where are the RCP bearing lift pumps powered from?

Answer 10

• 600v AC EZC panels

Question 11

What are the types of seals the RCP has?

Answer 11

• # 1 Seal - Film Riding
• # 2 Seal - Face Rubbing
• # 3 Seal - Face Rubbing
• Both 1 & 2 seals can handle RCS #

Question 12

What supplies cooling to the Motor Air coolers?

Answer 12

• NESW

Question 13

What supplies cooling to the Upper and Lower bearing oil coolers?

Answer 13

• CCW

Question 14

What supplies cooling to the thermal barrier heat exchangers?

Answer 14

• CCW

Question 15

What has to be done if you lost CCW to the RCPs or if the plant has had a Phase B actuation?

Answer 15

• Trip RCPs within 2 min to prevent damaging bearings

Question 16

Which ONE of the following completes the following statements?
The RCP Bearing Lift Pump WHITE light will illuminate (1) after sufficient oil pressure is developed. The RCP Bearing Lift pump (2) required to be started on a RCP Shutdown.

(1) 			        (2)
A. immediately 	is
B. immediately 	is NOT
C. 2 minutes 		is
D. 2 minutes 		is NOT

Answer 16

• B. (1) Immed (2) Is NOT

Question 17

What cools the RCP if there is a failure of seal injection to the seals?

Answer 17

• RCS then cools the RCP by leaking past the labyrinth seal and past the thermal barrier

Question 18

What does the shutdown seal do?

Answer 18

• Actuates when seal leakoff temp exceeds 250°F
• Rated for 24 hours
• Must actuate on stopped shaft
• Limits leakage to 1 gpm

Question 19

If there is a loss of CCW to the thermal barrier, does the RCP need to be tripped?

Answer 19

• No, as long as there is still seal flow and all parameters stay within spec

Question 20

If you have a rupture of the thermal barrier, where will it most likely indicate first if its a small leak?

Answer 20

• CCW Surge Tank Lvl