FR-P Daily Quiz

Question 1

How does RTndt change over vessel life and how does this affect the vessels fracture mechanics?

Answer 1

Rises, make the vessel more brittle at higher temps

Question 2

What is more limiting concerning RCS integrity, heat up or cooldown and why?

Answer 2

Cooldown due to tensile stress on inner wall

Question 3

What is the worst case PTS event and why?

Answer 3

SBLOCA when both RCS forced flow and natural circ flow are lost and cold RWST water reaches vessel belt line unmixed

Question 4

If multiple faulted SGs cause RCS cold leg temps to lower below 285 what will be the highest priority?

Answer 4

Implement FR-P.1 to try and prevent a crack in the vessel

Question 5

If the subcooling criteria for terminating SI in FR-P.1 is not satisfied what contingencies are performed?

Answer 5

Start RCP to mix ECCS flow to minimize thermal stresses

Question 6

What must the condition of RCS temp be for the one hour soak period of FR-P.1?

Answer 6

Stable, clock doesn’t start until its stable

Question 7

What are the major action categories of FR-P.1?

Answer 7

Stop RCS cooldown
Terminate SI
Depressurize RCS
Establish normal operating conditions
Soak if necessary

Question 8

What conditions would allow exiting FR-P.1 without performing any of the actions to minimize stresses on the vessel?

Answer 8

RCS Pressure < 300psig
and
RHR Flow > 400gpm

Question 9

How are hot leg temps and RCS presure controlled in FR-P.1 to mitigate a PTS event prior to the soak period?

Answer 9

Hold Hot Leg temp stable

Lower RCS pressure to minimize subcooling

Question 10

What actions may not be performed during the soak period per FR-P.1?

Answer 10

Raise pressure or lower temperature

Question 11

Are the SI termination criteria of FR-P.1 more or less restrictive than the standard termination criteria?

Answer 11

Less restrictive, to limit cooldown from ECCS and allow faster reduction in RCS pressure