40AO-9ZZ05 Loss of CH or LD

Question 1

During a Loss of LD what actions are taken if Lpzr is going up and 56% will be challenged

Answer 1

• All CH pump in PTL
• Close Seal Injection flow control vlvs
• App. C for extended operation without LD

Question 2

During a loss of LD what CH pump combination would you run, when

Answer 2

Lpzr 33% or greater and going up

- 1 CH pump only

Question 3

How do CHB-UV-515/523 differ on a high temperature failure

Answer 3

515 - requires jumper installed to reopen

523 - override and reopen (does not affect CIAS closure)

Question 4

Why do we minimize PZR Boron equalization during an extended loss of LD

Answer 4

Boron equalization depletes RCS hydrogen

Question 5

What are the major actions for App. C Extended loss of LD

Answer 5

• Minimize PZR Boron equalization
• Stop all CH pumps and Iso. seal inj. if 56% challenged
• Operate CH as needed for Lpzr 33-53% OR seal inj. needed

Question 6

How quickly will Bleedoff lower Lpzr with no CH

Answer 6

approx. 10% every 55 minutes

Question 7

During a loss of CH when would a Rx trip be required

Answer 7

Lpzr 33% and restoration not impending

Question 8

What are indications of CH gas binding

Answer 8

• CH hdr flow/press fluctuations
• CH hdr flow less than expected
• CH suction source level loss

Question 9

What actions should be taken for CH pump gas binding

Answer 9

• <40gpm isolate LD and all CH pump PTL
• > 40gpm determine pump bound
• Primary determination is noise
• once determined PTL affected pump and isolate locally

Question 10

When can a HPSI pump be used to maintain PZR level during a loss of CH

Answer 10

• Modes 3-5
• RWT >11%
• Aligned to Cold leg injection
• Prcs <1800psia

Question 11

During a loss of LD when can a plant cooldown be used to maintain Lpzr <56%

Answer 11

Modes 3-5