Abstract
An analytical method to obtain the amplitude of limit-cycle inphase oscillation in boiling water reactors is proposed, which is applicable to small-amplitude limit cycles actually observed in various stability tests. The expression of a zero-power transfer function including the limit-cycle amplitude can be derived by considering higher-order nonlinear interaction between neutron density and feedback reactivity. In a limit-cycle oscillation, the gainand phase-margin of the open-loop transfer function, which is defined by the product of the zero-power and a feedback transfer function, must be zero. From this requirement the oscillation amplitude and resonance frequency can be determined. A numerical example indicates that the fifth-order nonlinear approximation is adequate for the evaluation of the amplitude and that the resonance frequency is only slightly dependent on the amplitude. Assuming the independence of the resonance frequency from the amplitude, a simple formula can also be derived. When a resonance frequency is obtained by linear stability analysis, the oscillation amplitude can be readily determined from the formula expressed as a function of the amplitude by a polynomial.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
