Abstract
Channel stability, core-wide stability, and regional stability experiments were conducted for a wide range of operating conditions of a BWR-5 with UOX (uranium dioxide) type 9×9A fuels installed, including maximum power points along the minimum pump speed line and the natural circulation line. The SIRIUS-F facility, used in this study, was designed and constructed for highly accurate simulation of void-reactivity feedback of BWRs. The decay ratios and the resonance frequencies are in good agreement with those from the design analysis code, ODYSY. The SIRIUS-F experimental results demonstrated stability characteristics such as a stabilizing effect of the power, and revealed a sufficiently large stability margin even under hypothetical conditions of power enlargement.
