THERMIT-2: a two-fluid model for light water reactor subchannel transient analysis. Final report

Technical Report · Wed Apr 01 00:00:00 EST 1981

OSTI ID:5163002

Kelly, J E; Kao, S P; Kazimi, M S

The broad effort of developing and assessing the two fluid model computer code THERMIT for light water reactor (LWR) subchannel analysis is described. The developmental effort required a reformulation of the coolant-to-fuel rod coupling so that THERMIT is now capable of traditional coolant-centered subchannel analysis. A model that accounts for mass, momentum and energy transport between mesh cells due to turbulent mixing for two-phase conditions has also been introduced. This model is the first such attempt in a two-fluid context. The liquid-vapor interfacial exchange terms in the two-fluid model have been modified for improved accuracy. A systematic evaluation of the exchange models has been performed. The mass and momentum exchange rates between the vapor and the liquid for pre-CHF conditions were evaluated by comparison to void fraction data in over 30 one-dimensional steady-state experiments reported in the open literature. The liquid-vapor energy exchange rate for post-CHF conditions was assessed using 15 steady-state, one-dimensional wall temperature measurements. The mixing model was tested against G.E. and Ispra BWR and PWR rod-bundle measurements. Comparisons with these measurements have shown the appropriateness of this model.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Energy Lab.
• OSTI ID: 5163002
• Report Number(s): PB-82-180225; MIT-EL-81-014
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
COMPUTER CODES
T CODES
FUEL CHANNELS
TWO-PHASE FLOW
WATER COOLED REACTORS
COOLANTS
CRITICAL HEAT FLUX
FUEL ELEMENT CLUSTERS
REACTOR CORES
REACTOR SAFETY
TRANSIENTS
FLUID FLOW
FUEL ASSEMBLIES
HEAT FLUX
REACTOR CHANNELS
REACTOR COMPONENTS
REACTORS
SAFETY
220900* - Nuclear Reactor Technology- Reactor Safety