著者

上広 勝信 饒 燕飛 福田 研二

出版者

九州大学

雑誌

九州大学大学院総合理工学研究科報告 (ISSN:03881717)

巻号頁・発行日

vol.17, no.2, pp.245-252, 1995

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An analytical model is proposed to study regional instabilities in parallel boiling channels with the voidreactivity feedback. The model takes into consideration the effect of interaction between channels with different void fraction change by modeling the diffusion of neutrons. Linear stability analysis in the frequency domain is performed to investigate dominant factors of unstable oscillation mode. In the case of 2 channels, two stability boundaries are found to exist on the stability map, one for the in-phase and the other for the out-of-phase mode instabilities respectively. It is found that the interaction between channels affects the out-of-phase mode instability. For a certain range of the void-reactivity coefficient, the void-reactivity feedback loop is found to be unstable in a certain region on the stability map, which has an effect on the stability of the in-phase mode stability.