Random media criticality analysis using randomized Fourier series and incomplete randomized Weierstrass function

Ueki, Taro  

Criticality analysis of continuously mixed random media is crucial for safely retrieving fuel debris. Initially, a Monte Carlo method was established using the Incomplete Randomized Weierstrass Function (IRWF) to model a single-mode inverse power law power spectrum. However, image analysis showed that oxide debris mock-ups require a more complex model. To address this, a new function called the Randomized Fourier Series (RFS) was developed to represent arbitrary power spectra. RFS is versatile, incorporating Brownian motion models and aiding reactor physicists in analyzing various scenarios. Numerical results compare the fluctuation of neutron multiplication factor in various media generated by RFS and IRWF, identifying the spectral range most affecting k.