FR-S Daily Quiz Flashcards
What is a Condition 2 event?
Moderate frequency
Plant capable of recovery with corrective action
Shall not cause loss of fuel cladding or fission product barriers
What is an ATWS?
Common failure which prevents rods from being inserted into the core (condition 2 event)
Design basis of Reactor Protection System?
Maintain minimum DNBR
Maintain RCS Pressure within design limits
What fission product barriers are challenged the most by an ATWS?
Fuel Clad
Pressure Boundary
Biggest chance to challenge to DNB from ATWS?
LOOP due to loosing all RCPs
Biggest chance to challenge RCS pressure boundary from ATWS?
Loss of load causing significant temperature rise
Why shouldn’t a manual SI be initiated until at the required setpoint during an ATWS?
SI causes a Feed Water Isolation
Three possible causes of positive reactivity during an ATWS?
Control Rods fail to fully insert
Dillution of the RCS
Excessive cooldown
Events assumed by ATWS analysis?
Loss of Turbine Load Loss of Feed Water LOOP RCS depressurization Rods uncontrolled withdrawl
Immeadiate actions of FR-S.1 an basis?
Check RX trip - safeguards assume only heat input from decay heat and RCP heat
Actuate AMSAC - start AFW and ensure turbine tripped
Turbine Trip - prevent uncontrolled cooldown to not challenge SG inventory
Major actions of FR-S.1?
Reduce core power
Borate
Check for possible sources of positive reactivity
Verify subcritical
What is the basis for checking RCS pressure less than PRZ PORV setpoint in FR-S.1?
Verifies boration flow possible
What key indication allows you to exit FR-S.1 following an ATWS?
WR Power <5% and a negative SUR
What is the minimum AFW flow during an ATWS event?
450K lbm/hr
If SI is actuate during an ATWS what must operator do to verify boration flow?
Check RCS Pressure <2335 psig
