An analytical and experimental investigation of natural circulation transients in a model pressurized water reactor
Natural Circulation phenomena in a simulated PWR was investigated experimentally and analytically. The experimental investigation included determination of system characteristics as well as system response to the imposed transient under symmetric and asymmetric operations. System characteristics were used to obtain correlation for heat transfer coefficient in heat exchangers, system flow resistance, and system buoyancy heat. Asymmetric transients were imposed to study flow oscillation and possible instability. The analytical investigation encompassed development of mathematical model for single-phase, steady-state and transient natural circulation as well as modification of existing model for two-phase flow analysis of phenomena such as small break LOCA, high pressure coolant injection and pump coast down. The developed mathematical model for single-phase analysis was computer coded to simulate the imposed transients. The computer program, entitled ''Symmetric and Asymmetric Analysis of Single-Phase Flow (SAS),'' were employed to simulate the imposed transients. It closely emulated the system behavior throughout the transient and subsequent steady-state. Modifications for two-phase flow analysis included addition of models for once-through steam generator and electric heater rods. Both programs are faster than real time. Off-line, they can be used for prediction and training applications while on-line they serve for simulation and signal validation. The programs can also be used to determine the sensitivity of natural circulation behavior to variation of inputs such as secondary distribution and power transients.
- Research Organization:
- Maryland Univ., College Park (USA). Dept. of Chemical and Nuclear Engineering; Nuclear Regulatory Commission, Washington, DC (USA). Div. of Reactor Systems Safety
- OSTI ID:
- 6839824
- Report Number(s):
- NUREG/CR-4788; ON: TI87900512
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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PWR TYPE REACTORS
REACTOR COOLING SYSTEMS
TRANSIENTS
NATURAL CONVECTION
AUXILIARY SYSTEMS
DATA ACQUISITION SYSTEMS
FLOW MODELS
FLUID FLOW
MATHEMATICAL MODELS
MOCKUP
TWO-PHASE FLOW
CONVECTION
COOLING SYSTEMS
ENERGY SYSTEMS
ENERGY TRANSFER
HEAT TRANSFER
MASS TRANSFER
REACTOR COMPONENTS
REACTORS
STRUCTURAL MODELS
WATER COOLED REACTORS
WATER MODERATED REACTORS
210200* - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled