Modeling of Critical Heat Flux in Light-Water Flow with Heavy-Water-Based Correlation

Abstract

Critical heat flux (CHF) data were obtained with light-water flow over a 37-element bundle simulator and were transformed into heavy-water-equivalent values using the fluid-to-fluid CHF modeling parameters. These equivalent values were used to derive a heavy-water-based CHF correlation for use in regional-overpower protection and safety analyses. The heavy-water-based CHF correlation has been assessed against the light-water CHF data for the 37-element bundle directly without applying the fluid-to-fluid modeling parameters. The assessment indicated an underprediction of about 5% of the light-water CHF data. This implies that applying the light-water correlation would overpredict the heavy-water CHF data by a similar bias.