Performance of the liquid reactivity control system in BWRs (boiling water reactors)
- California Univ., Santa Barbara, CA (USA). Dept. of Chemical and Nuclear Engineering
Boiling water reactors rely on the injection of soluble neutron absorbers to control power in case of failure in the control rod (scram) system. Typically this liquid poison'' is injected from eight small holes on a standpipe positioned vertically near the outer edge of the core shroud in the lower plenum. The achievement of control is predicated on good mixing of this injected liquid with the coolant which is recirculating around the core upper plenum and downcomer. However, because the flows are rather low ({approximately}20% of rated with pumps tripped as expected under such conditions) and the injected solution density is much higher than that of the primary fluid, there have been concerns raised about the efficiency and completeness of this mixing. This work provides the first openly available data addressing such concerns. To avoid potentially important scaling compromises, the data were obtained from full-scale simulations. From the experiments performed so far, we can conclude that complete boron mixing (entrainment) will occur for recirculation flow rates down to 8.2% of rated. 3 refs., 60 figs., 2 tabs.
- Research Organization:
- Nuclear Regulatory Commission, Washington, DC (USA). Div. of Regulatory Applications; California Univ., Santa Barbara, CA (USA). Dept. of Chemical and Nuclear Engineering
- Sponsoring Organization:
- USNRC
- OSTI ID:
- 5387472
- Report Number(s):
- NUREG/CR-5422; ON: TI90002986; TRN: 90-001087
- Country of Publication:
- United States
- Language:
- English
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99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
BWR TYPE REACTORS
REACTOR CONTROL SYSTEMS
BORON
COMPARATIVE EVALUATIONS
DRESDEN-3 REACTOR
EFFICIENCY
FLOW RATE
FLUID POISON CONTROL
FUNCTIONAL MODELS
GEOMETRY
HEAT TRANSFER
HYDRAULICS
LOSS OF COOLANT
MATHEMATICAL MODELS
MIXING RATIO
PEACH BOTTOM-3 REACTOR
REACTIVITY
REACTOR COOLING SYSTEMS
REACTOR CORES
REACTOR SAFETY
RESEARCH PROGRAMS
SCRAM
ACCIDENTS
CONTROL
CONTROL SYSTEMS
COOLING SYSTEMS
ELEMENTS
ENERGY SYSTEMS
ENERGY TRANSFER
ENRICHED URANIUM REACTORS
FLUID MECHANICS
MATHEMATICS
MECHANICS
POWER REACTORS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR SHUTDOWN
REACTORS
SAFETY
SEMIMETALS
SHUTDOWNS
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
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