Integrity & Inventory Control CSFs (RQ-C-4771)

Question 1

During a LBLOCA, a red path on Integrity causes the crew to Transition to FR-P.1. If the E RHR pump is tagged out and the West RHR tripped on overcurrent, how should the crew navigate through Step 1?

Answer 1

RHR flow verification is a back up to RCS pressure indication. During a LBLOCA, PTS is not a serious concern and FR-P.1 does not need to be implemented.

Question 2

How is the ECCS flow termination criteria in FR-P.1 less restrictive than ES-1.1 termination criteria

Answer 2

FR-P.1 only cares about the core being covered (RVLIS > 59%) whereas ES-1.1 requires level to be in the pressurizer.

This is because you want to stop any cool down and mass injection caused by ECCS while in FR-P.1 once you have validated that a SBLOCA is not in progress (Subcooling > 90 deg F)

Question 3

What are the Major Action Categories for FR-P.1 in your own words (i.e., what is the overall strategy for FR-P.1)

Answer 3

• Stop Cooldown
• Terminate SI if possible
• Depressurized
• Stabilize
• Soak