Fundamental philosophy on the safety design of the HTTR-IS hydrogen production system

Ohashi, Kazutaka; Nishihara, Tetsuo ; Kunitomi, Kazuhiko 

Japan Atomic Energy Agency (JAEA) has been conducting an R&D work on the VHTR reactor system and IS hydrogen production system to realize hydrogen production using nuclear heat. As a part of this activity, JAEA is planning to connect an IS test system to the High Temperature Engineering Test Reactor (HTTR) to demonstrate its technical feasibility. This paper proposes a fundamental philosophy on the safety design of the HTTR-IS hydrogen production system including the methodology to select postulated abnormal events and its event sequences and to define safety functions of the IS system to ensure the reactor safety. Also the measure to clarify the IS system as non-reactor system is proposed.