PRA Flashcards
TRA00221
Why did the columbia shuttle disaster occur?
No risk analysis
What defines CDF threshold?
> 10% of core
What defines FDF threshold?
<10% of core
What are included in CDF?
Fuel in the core and canal
What is PRA level 1?
Determine the frequency or probability per year of severe fuel damage event sequences
What is PRA level 2?
Determine the characteristics and frequency of radionuclide release to the environment
What is PRA level 3?
Determine the health and other consequences to the public and INL
What level does the ATR PRA project encompass?
Level 2 analysis
What is the power limit for Power Ops PRA?
> 3 MW
What is the power limit for shutdown and fuel handling PRA?
< 3 MW
What are the four initiating event groups for PRA?
Reactivity insertion
Transients
Loss of coolant
Canal and load handling
What are the success criteria to protect fuel cladding?
Reactivity control/shutdown
Core decay heat removal
Core coolant inventory control
Canal irradiated fuel storage coolant inventory control
What are the success criteria to protect PCS pressure boundary?
PCS Pressure control
PCS integrity
Severe external events (seismic)
What are the success criteria to protect confinement?
Plant conditions
Plant/equipment response
Personnel response
What are the two general event trees?
Transient ET
Canal drain ET
What are the End States or ATR Plant Damage States?
P1-P2: PCS Failure and Core Uncovery
P3M: Direct damage
P4: ATWS
P3/6/9: LOCAs
P5/P5M: Reactivity Insertions
P7/P8: Canal Draining and Fuel Uncovery
P10: Core crushing
PFD-1/2/3: Local fuel damage
What are the specific success criteria that protect fuel cladding?
Reactivity control
Decay heat removal
EFIS
Vessel vents
Vessel level alarm
LOCA PCP shutoff
What are the specific success criteria that protect PCS pressure boundary?
High pressurepzr and gs pump shutoff
Vessel high dp PCP shutoff
Primary relief valves
Design to meet seismic criteria
