Development scenario of the iodine-sulphur hydrogen production process to be coupled with VHTR system as a conventional chemical plant

Japan Atomic Energy Agency (JAEA) started design studies of the thermochemical water-splitting iodine-sulphur (IS) process to be coupled with the HTTR to demonstrate hydrogen production from a very high-temperature reactor (VHTR) system. It is important from an economic point of view that a non-nuclear-grade, rather than nuclear-grade, IS process plant be built based on conventional chemical plant construction standards. In order to construct the IS process as a conventional chemical plant, some critical safety issues must been studied and clarified prior to the application for safety case review from the government. JAEA has launched R and D for a non-nuclear-grade IS process to be coupled with the HTTR, which is the Japan's first VHTR capable of supplying 900degC secondary helium for process heat application. In this paper, we describe the development scenario for a non-nuclear grade hydrogen production system. Utilizing the HTTR-IS system as a reference system, the R and D map is proposed for the VHTR-IS hydrogen production system. (author)