Feasibility study on naturally safe HTGR (NSHTR) for air ingress accident

摘要: Abstract A new design activity for an advanced reactor, referred to as a naturally safe high temperature gas-cooled reactor (NSHTR), has been launched by authors after the accident at Fukushima Daiichi Nuclear Power Station. The concept of NSHTR is that release radioactive materials kept very low level and no harmful effect on people environment ensured only physical phenomena even in absence engineered safety features. At air ingress accident, possible events lead loss or degradation confinement function fuel-coating layers are crack coatings caused explosion carbon monoxide (CO) produced graphite oxidation failure melting sublimation core heat up due reaction oxidation. In this study, CO concentration generated inside circular tube were evaluated parametrically using steady-state one-dimensional model confirm feasibility severe condition (i.e., massive simultaneous rupture two primary pipes). It was confirmed outlet coolant channel can be maintained below limit with oxygen air, removed decay under certain conditions geometry without any results revealed technically feasible terms suppression removal accident.