Analysis of Coolant Pressure Fluctuation and Induced Vibration of Liquid-Metal Fast Breeder Reactor Fuel Pins

An analytical model describing pressure fluctuation of turbulent flow in liquid-metal fast breeder reactor (LMFBR) fuel assemblies has been proposed, and the oscillation amplitude of a fuel pin thus caused has been calculated. In the treatment, the statistical model for pressure fluctuation in stable turbulent flow was assumed, and the fluctuation was estimated from pressure loss of flow and velocity gradient. The vibration amplitude was calculated by solving a Langevin equation. According to the comparison of the calculated results with experimental data, this model realistically describes the fuel pin vibration in LMFBR fuel assemblies.