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Title: Westinghouse best-estimate LOCA analysis model: WCOBRA/TRAC

Conference · · Trans. Am. Nucl. Soc.; (United States)
OSTI ID:7118611

A rule change for 10CFR50.46 and Appendix K has been proposed by the US Nuclear Regulatory Commission (NRC). This change would allow the use of realistic (best-estimate) thermal-hydraulic computer codes to predict the emergency core cooling system performance for a postulated large-break loss-of-coolant accident (LOCA). The NRC staff expects that the analytical techniques used for predicting the design-basis large-break LOCA, will use realistic thermal-hydraulic models and will be based on applicable experimental data. WCOBRA/TRAC is a three-dimensional separated flow code that models the two-phase flow with three component fields: vapor phase, continuous liquid phase, and entrained liquid. The formulation of the governing equations is complete and includes turbulence models for the continuous phase. There is one continuity equation for each field, three momentum equations for each field (total of 9), and two energy equations. WCOBRA/TRAC meets the requirements for a realistic thermal-hydraulic model, which can be used to accurately predict postulated accident transients for a pressurized water reactor.

OSTI ID:
7118611
Report Number(s):
CONF-8711195-; TRN: 88-032073
Journal Information:
Trans. Am. Nucl. Soc.; (United States), Vol. 55; Conference: American Nuclear Society winter meeting, Los Angeles, CA, USA, 15 Nov 1987
Country of Publication:
United States
Language:
English