Hydrogen production by thermochemical water-splitting IS process utilizing heat from high-temperature reactor HTTR

Sakaba, Nariaki ; Kasahara, Seiji  ; Ohashi, Hirofumi ; Sato, Hiroyuki  ; Kubo, Shinji  ; Terada, Atsuhiko  ; Nishihara, Tetsuo ; Onuki, Kaoru; Kunitomi, Kazuhiko 

High-temperature reactors (HTRs) are particularly attractive due to their wide industrial application from electricity generation to hydrogen production. The Japan Atomic Energy Agency's (JAEA's) HTTR, which is the first HTR in Japan, attained its maximum reactor-outlet coolant temperature and successfully delivered 950C coolant helium outside its reactor vessel. A hydrogen production system based on the thermochemical water-splitting iodine sulphur (IS) process is planned to be connected to the HTTR in the near future. This will establish the hydrogen production technology with an HTR, including the system integration technology for connection of hydrogen production system to HTRs. It will probably be the world's first demonstration of hydrogen production directly using heat supplied from an HTR. The HTTR-IS system design was launched from a conceptual design in 2005. This paper shows the summary of the HTTR, plan for developing the IS process in JAEA, thermal efficiency evaluation for the HTTR-IS system, etc. The verification of the hydrogen production by the HTTR-IS system by using heat from a nuclear reactor is greatly expected to contribute to the commercialization of nuclear hydrogen in coming hydrogen society.