Critical Heat Flux Tests for an Application of the Three-Pin Fuel Test Loop in HANARO

摘要

Critical heat flux (CHF) tests in a three-rod bundle were carried out, and a CHF database was established in order to obtain an operational license for the three-pin fuel test loop (FTL) in HANARO (High-flux Advanced Neutron Application Reactor). Two kinds of CHF tests are currently being performed for the CANDU and PWR-type fuel test loop. In this study, an experimental work on the CHF tests for the CANDU-type fuel test loop is explained, and a new CHF prediction methodology is proposed. In all, 108 experimental data points have been obtained, and the data are analyzed and compared with the available CHF correlations for a bundle or an annulus geometry. The 1986 AECL look-up table with a bundle correction factor and the Doerffer's correlation for annuli are compared with the present CHF data. It is found that the 1986 AECL look-up table with a bundle correction factor results in a better prediction than the Doerffer's correlation for annuli geometry. A three-pin correction factor is developed to account for the geometric effects of the three-rod bundle and to improve the prediction accuracy. It is concluded that the best estimate thermal hydraulic system code, MARS 3.0, which uses the same look-up table for a CHF prediction, can be used for a safety analysis of the CANDU-type three-pin FTL to obtain a license if it is corrected by the developed three-pin correction factor.