This article presents a summary of the development of the computer code AZKIND. This code is based on multi-group neutron diffusion theory, where the kinetics equations include delayed neutron precursors. For space discretization a Galerkin process is applied using a nodal finite elements method, and the well-known 8-method is used for time discretization. A high performance computing methodology was implemented in AZKIND to solve the resulting linear algebraic system A (v) over right arrow = (b) over right arrow where numerical solution of large algebraic systems representing full nuclear reactor cores is achieved with an acceleration technique based on the open source linear algebra PARALUTION library. This implementation allows AZKIND threading into a GPU thousands of arithmetic operations for parallel processing. The acceleration is demonstrated with the use of different nuclear fuel arrays resulting in extremely large matrices, getting a speedup ratio up to 48. Finally, the acceleration capabilities of the HPC implementation are presented in the simulation of a power transient in an actual boiling water reactor core. (C) 2016 Elsevier Ltd. All rights reserved.