Residual Heat Removal System (RHR)

Question 1

What causes a RHR pump to Auto Start

Answer 1

L1 17.8”
1.68#s in DW

Question 2

P1 A/B RHR Pump Trips

Answer 2

1. Loss of suction path
   - MOV1 (supp pool suction) closed
   OR
   - MOV2, 112, 113 closed

Question 3

When does RHR pumps realign to inject?

Answer 3

Always re-aligns to inject except SDC. The pump will trip if in SDC.

Question 4

Is LPCI mode OPERABLE during Supp Pool Cooling?

Answer 4

LPCI Mode is INOP during Supp Pool Cooling due to the time required to align to LPCI Mode.

Question 5

How many starts in succession are allowed from ambient temp?

Answer 5

2 starts
After the 2 starts a 60 min wait is required.

Question 6

How many starts in succession are allowed from rated temp?

Answer 6

1 start
After the attempted start a 60 min wait is required prior to subsequent starts.

Question 7

What must be done when aligning B RHR return to supp pool and why?

Answer 7

2RHS*MOV4C must be closed due to the potential for air getting into P1C in the event of a LOOP/LOCA.

Question 8

What is the desired Supp Pool level when preparing to drain the Rx Cavity?

Answer 8

196.5’

Question 9

What is MAX total Drive Flow during an outage?

Answer 9

5,700gpm
- protect incore instrumentation.

Question 10

What are the Interlocks for MOV1 Supp Pool Suction valve

Answer 10

1. MOV2 A/B must be shut (prevent draindown)

Question 11

What are the Interlocks for MOV2 SDC Suction valve

Answer 11

MOV1, 33, 38 A/B must be shut. (prevent draindown)

Question 12

What are the Interlocks for MOV8 A/B HX bypass valves

Answer 12

Opens on a LOCA with a 10 min seal-in. If manually closed it will re-open. This is to maximize LPCI flow.

Question 13

What are the Interlocks for MOV33 A/B Supp Chamber Spray valves

Answer 13

1. Closes on LOCA (maximize LPCI)
2. Manual Open during LOCA. (amber light)
   - LOCA signal in
   - MOV24 shut
   - DW >1.68#s
   - auto closes when DW <1.68
3. Normal Ops - can only open if MOV2 A/B shut

Question 14

What are the Interlocks for MOV15/25 A/B DW Spray valves

Answer 14

1. Both can open if:
   - LOCA signal
   - DW>1.68
   - MOV24 shut
2. Does NOT auto close.
   - DW pressure <1.68 valve will stop where it is and must be manually closed.
3. Normal Ops - can only open 1 at a time.

Question 15

What are the Interlocks for MOV38 A/B/C Supp Pool Cooling valves

Answer 15

1. Closes on LOCA
2. Can override Open during LOCA with MOV24 shut. Amber light wil clear when LOCA signal is reset.
3. Normal Ops - Can open if MOV2s are shut.

Question 16

What are the Interlocks for MOV24 A/B/C LPCI injection valves

Answer 16

1. Opens with LOCA signal
   AND
   - <130psid discharge to RPV (~480#s RPV)
   - Can be manually closed (amber light)
   - Will stay overridden until the LOCA signal has been manually reset on PNL 601.
   - Will NOT auto open if overridden
   - Will continue to stroke open with motor overload with LOCA signal. (Throttleable if no LOCA)