Generation-IV nuclear power plants represent a set of advanced reactor designs that are currently going through extensive research for commercial applications. Generation-IV nuclear energy systems include the nuclear reactor, its energy conversion systems and necessary fuel-cycle technologies.
The Generation IV International Forum (GIF) selected six systems as generation-IV technologies: gas-cooled fast reactor (GFR), lead-cooled fast reactor (LFR), molten salt reactor (MSR), sodium-cooled fast reactor (SFR), supercritical-water-cooled reactor (SCWR) and very high-temperature reactor (VHTR) (NEA, 2014). According to IAEA (2013), the VHTR system is considered the prime candidate for large scale hydrogen production. The VHTR is a graphite-moderated, helium-cooled reactor with thermal neutron spectrum. It can be used for heat applications such as process heat for hydrogen production – the heat application process is generally coupled with the reactor through an intermediate heat exchanger. The VHTR can produce hydrogen by using thermochemical processes, combined thermochemical and electrolysis, high temperature steam electrolysis, or from heat, water and natural gas by applying the steam reformer technology (NEA, 2014).