Conceptual design of the HTTR-IS hydrogen production system; Assumed abnormal accidents caused by the IS process

Sato, Hiroyuki  ; Ohashi, Hirofumi ; Sakaba, Nariaki ; Nishihara, Tetsuo ; Kunitomi, Kazuhiko 

Japan Atomic Energy Agency (JAEA) has been conducting R&D on the hydrogen production system to be coupled with the high-temperature gas-cooled reactors (HTGRs). Thermochemical water-splitting iodine-sulphur process (IS process) is a progressive candidate for its hydrogen production system. Since the reactor needs to keep its operation during abnormal events caused by the IS process in the hydrogen production system coupled with HTTR (HTTR-IS system), countermeasure for the abnormal accidents caused by IS process should be established. In this study, assumed abnormal accidents caused by IS process was extracted and dynamic behaviour of the HTTR-IS system during the abnormal condition was calculated by the newly developed dynamic simulation code based on the RELAP5 code. It was confirmed that the cooling system using steam generator with air cooler had superb functionality to mitigate the influence of abnormal events caused by the IS process.