Non symmetric alternating direction explicit method applied to the calculation of ADS transients

Highlights: • Transients in ADS time reactors are simulated using NSADE spatial kinetics method. • A code was developed for this purpose and has been validated with results in literature. • It was possible to predict the general behavior of two-dimensional subcritical system driven by an external source, which made it possible to infer about evolution of these systems under transient conditions. - Abstract: ADS systems – Accelerator Driven Systems, along with Generation IV reactors, have been receiving great attention, especially due to their capability of transmutation and eventually incineration of nuclear waste. To study ADS safety aspects, kinetic models are used to analyze transients. Currently, there are quite a few studies involving transient in ADS systems. Furthermore, most existing studies make use of the Point Kinetics equations. In this context, this work presents a proposal to implement a space dependent kinetics formalism, the Non-Symmetric Alternating Direction Explicit Method, to analyze ADS systems under transient conditions. The computer code developed in this study has satisfactorily reproduced results in the literature of the transients tested. The results are in accordance to what should be expected from the physical point of view.