Numerical simulation of non-steady state neutron kinetics of the TRIGA Mark II reactor Vienna

•Power changes after reactivity changes have been measured with high time resolution.•Time dependent power changes after reactivity changes have been calculated numerically including feedback mechanisms.•The model has been verified by comparing numerical results to experimental data.•The verified model has been used to predict time dependent power changes after several reactivity changes. This paper presents an algorithm for numerical simulations of non-steady states of the TRIGA Mark II reactor in Vienna, Austria. The primary focus of this work has been the development of an algorithm which provides time series of integral neutron flux after reactivity changes introduced by perturbations without the usage of thermal-hydraulic/neutronic numerical code systems for the TRIGA reactor in Vienna, Austria. The algorithm presented takes into account both external reactivity changes as well as internal reactivity changes caused by feedback mechanisms like effects caused by temperature changes of the fuel and poisoning effects. The resulting time series have been compared to experimental results.