THEDA-2 Code Verification with Data from Model Tests of a Once-Through Steam Generator

A computer code (THEDA-2) developed for predicting the thermal and hydraulic performance of nuclear once-through and inverted U-tube steam generators was benchmarked. Data from a full-length laboratory steam generator, representative of Babcock & Wilcox once-through nuclear steam generators, were obtained and compared to THEDA-2 predictions. Two geometrical arrangements of the laboratory steam generator were tested to produce detailed, multidimensional data for thoroughly evaluating THEDA-2 capabilities. Agreement between code-predicted and measured steam generator fluid temperatures was good -- generally within 5°F (2.8°C). Results from this study indicated that further improvements in predictive capabilities will come from improvement in empirical correlations.