Abstract
In the current work, the stochastic point reactor model is analyzed using the Wiener-Hermite expansion (WHE). The simplified stochastic point reactor model (Ayyoubzadeh and Vosoughi, 2014), at which no matrix square root, is considered. The stochastic system is reduced to a set of deterministic equations that are solved to get the mean and variance of the neutron and precursor populations. The well-known numerical deterministic techniques are used to get the solution without the need for the time-consuming sampling techniques. Estimations of the neutron and precursor groups fluctuations at the startup are quantified. Many cases are tested and compared with the results in the literature. The current technique is shown to be efficient, accurate and simple compared with the available techniques. (C) 2019 Elsevier Ltd. All rights reserved.