Hydrogen, rather than oil, must be produced in volumes not provided by the currently employed methods. In this work, two high-temperature hydrogen production methods coupled with an advanced nuclear system are presented. A new design of a pebble-bed accelerator nuclear-driven system called TADSEA (Transmutation Advanced Device for Sustainable Energy Applications) was chosen because of the advantages in transmutation and safety. A detailed flowsheet of the high-temperature electrolysis process coupled to TADSEA through a Brayton gas cycle was developed using chemical process simulation software: Aspen HYSYS (R). It is obtained 0.1627 kg/s of hydrogen with the model with optimized operating conditions, resulting in an overall process efficiency of 34.51%, a value in the range of results reported by other authors. A conceptual design of a plant using the iodine-sulfur thermochemical water splitting cycle was carried out producing 5.66e-2 kg/s and electric energy in cogeneration. The overall efficiency was calculated performing an energy balance resulting in 22.56%. A brief hydrogen production cost estimation was performed for both methods obtaining 5.96$/kg for the sulfur-iodine (SI) and 4.8 $/kg for the high-temperature electrolysis (HTE) process. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.