American Nuclear Society

Home / Store / Journals / Electronic Articles / Nuclear Technology / Volume 128 / Number 2

Evaluation of the Slip Options in RETRAN-3D

Daniel Maier, Paul Coddington

Nuclear Technology

Volume 128 / Number 2 / November 1999 / Pages 153-168


Member Price:$27.00
Member Savings:$3.00

The RETRAN-3D code provides the user with a range of options for calculating the liquid-vapor slip. In the three-equation model, for example, two drift flux correlations are available, while the four-equation model includes an additional momentum equation with three interphase friction options. To assess the adequacy of these options, RETRAN-3D has been evaluated against a wide range of rod bundle void fraction data. The data used for this analysis includes information on 83 experiments from nine facilities performed in four different countries.

The results of the assessment show that all options provide an excellent prediction of the data for conditions typical of boiling water reactor normal operation. However, there is a progressive worsening of the predictive quality of all options, except that of the Chexal-Lellouche correlation, as first the flow rate and second the system pressure is reduced. At low mass fluxes and pressures, there is some overprediction by the Chexal-Lellouche correlation, while at very low pressures the code fails to reach a converged solution. An assessment of the five-equation subcooled boiling model shows an overprediction of the void fraction for negative values of the equilibrium quality.

Questions or comments about the site? Contact the ANS Webmaster.