BWR 9×9 Fuel Assembly Thermal-Hydraulic Tests: 1 — New Formula for Post Boiling Transition Heat Transfer Correlation and Rewet Correlation

Nuclear Power Engineering Corporation (NUPEC) conducted thermal-hydraulic projects for verification of thermal-hydraulic design reliability for BWR high-burnup 8 x 8 and 9 x 9 fuel assemblies, entrusted by the Ministry of Economy, Trade and Industry (METI). As a part of the NUPEC thermal-hydraulic projects, post boiling transition (post-BT) tests by the use of full-scale test assemblies simulating 9 x 9 fuel were carried out to evaluate BWR fuel integrity. Two kinds of post-BT tests, the steady-state post-BT test and transient post-BT test were performed, and the test results were applied to development of new heat transfer and re-wet correlations for the estimation of fuel rod surface temperature. (authors)