HTTR-IS Nuclear Hydrogen Demonstration Program in Japan

Recently, climate changes and effect to the ecosystem are concerning because of the global warming induced by the emissions of greenhouse gases such as carbon dioxide. Nuclear hydrogen production is gathering worldwide attention since it can produce hydrogen, a promising energy carrier, without an environmental burden. In 2008, a massive hydrogen production technology utilizing nuclear heat source was selected as one of the innovative technologies which could achieve a favorable balance between a sustainable development and an environmental protection was undertaken by the Council for Science and Technology Policy [1]. Also, the Japan Atomic Energy Commission addressed a roadmap of nuclear energy research and development (R&D) [2] positioning the nuclear hydrogen production as a candidate of the technologies that can achieve the vision for applying a nuclear reactor as a heat source. In the roadmap, it is declared that the prototype demonstration of commercial nuclear hydrogen plants should start by 2020. Japan Atomic Energy Agency (JAEA) has been conducting R&D on enabling technologies for nuclear hydrogen demonstration. High-Temperature Gas Reactor (HTGR) was selected as nuclear heat source due to the reactor’s inherent safety, economic viability, high efficiency, very high burn up, and wide industrial applicability from electricity generation to hydrogen production. As for the reactor technology, R&D related to fuel, material, thermalfluid, neutronics, and high-temperature components technologies have been conducted since 1970s. Based on the technology, the HTTR (high-temperature engineering test reactor, which is the first HTGR in Japan, has been constructed and is in operation at the site of JAEA Oarai R&D Center) [3]. The HTTR has successfully delivered 950°C helium coolant to the outside of the reactor vessel [4]. The reactor outlet coolant temperature of 950°C makes CONTENTS