Presentation Information
[2D15]Stochastic Equation Modelling of Fuel Debris Power Spectrum
*Taro Ueki1 (1. Japan Atomic Energy Agency)
Keywords:
stochastic differential equation,fuel debris,power spectrum,Solomon,randomization,criticality fluctuation
The Solomon code has refined its method for evaluating criticality fluctuations of fuel debris by generating randomized replicas so that their power spectra can range from inverse power-law forms to arbitrary shapes. To make full use of these capabilities of power spectra, we have developed a mathematical model that includes a white-noise term, a resistance term representing effects such as air or fluid drag, and a restoring-force term representing inertia. We solved the corresponding stochastic differential equation, derived by transforming white noise into Brownian motion, using a standard numerical method. The results show that the model can reproduce the spectral characteristics observed in the image analysis of a fuel debris mock-up.