Loss of DHR sequences at Browns Ferry Unit One - accident-sequence analysis
This study describes the predicted response of Unit One at the Browns Ferry Nuclear Plant to a postulated loss of decay heat removal (DHR) capability following scram from full power with the power conversion system unavailable. In accident sequences without DHR capability, the residual heat removal (RHR) system functions of pressure suppression pool cooling and reactor vessel shutdown cooling are unavailable. Consequently, all decay heat energy is stored in the pressure suppression pool with a concomitant increase in pool temperature and primary containment pressure. With the assumption that DHR capability is not regained during the lengthy course of this accident sequence, the containment ultimately fails by overpressurization. Although unlikely, this catastrophic failure might lead to loss of the ability to inject cooling water into the reactor vessel, causing subsequent core uncovery and meltdown. The timing of these events and the effective mitigating actions that might be taken by the operator are discussed in this report.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6168063
- Report Number(s):
- NUREG/CR-2973; ORNL/TM-8532; ON: DE83012314
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of small-capacity, high-pressure injection systems on TQUV sequences at Browns Ferry Unit One
Severe-accident-sequence assessment of hypothetical complete-station blackout at the Browns Ferry Nuclear Plant
Related Subjects
210100 -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
AFTER-HEAT REMOVAL
BROWNS FERRY-1 REACTOR
BWR TYPE REACTORS
COMPUTER CALCULATIONS
CONTAINMENT
CONTAINMENT SYSTEMS
COOLING SYSTEMS
ENERGY SYSTEMS
ENERGY TRANSFER
ENGINEERED SAFETY SYSTEMS
ENRICHED URANIUM REACTORS
FAILURES
FLUID MECHANICS
HEAT TRANSFER
HYDRAULICS
MECHANICS
MIXED SPECTRUM REACTORS
POWER REACTORS
PRESSURE GRADIENTS
PRESSURE SUPPRESSION
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR SAFETY
REACTORS
REMOVAL
RHR SYSTEMS
SAFETY
TEMPERATURE GRADIENTS
WATER COOLED REACTORS
WATER MODERATED REACTORS