Uncertainty analyses of neutron noise simulations in a Zero-Power reactor

A comprehensive uncertainty analysis methodology has been established for the modeling of stationary neutron flux oscillations induced by fuel rods vibration in a zero-power reactor. The includes propagation and sensitivity analysis. target event is based on an actual experimental campaign at CROCUS reactor corresponds to simultaneous oscillation 18 metallic uranium periphery core. Both commonly use large part entire process, from selection uncertain parameters code simulations. Applying random sampling-based approach, input are sampled N times their distribution information used as inputs noise simulations using CORE SIM +. quantity interest (QoI) amplitude Auto-Power Spectral Density various detector locations, which normalized Cross-Power reference detector. Their uncertainties determined following 4th order Wilks’ formula two-sided limits. Through determination correlations among QoI installed it demonstrated that near area oscillating (noise source) have different behavior compared further away source. analyses carried out multiple correlation coefficients within grouped parameters. As expected correlations, QoIs two locations (near far influenced Near source, driven position while nuclear data U-235 U-238 leading contributors This paper provides general how perform simulations, well quantitative estimates computational required validation computer programs under development simulation noise.