Development of HTTR fuel temperature estimation model

Tochio, Daisuke ; Fujimoto, Nozomu; Nojiri, Naoki ; Nakagawa, Shigeaki  

In the High Temperature engineering Test Reactor established in JAEA, the reactor outlet coolant temperature of 950 C is achieved at April, 2004. In the current HTTR fuel temperature estimation model, the homogenized fuel block model is used and maximum fuel temperature is estimation with the consideration of hot spot factor representing heterogeneous-model effect. This method was used in the HTTR designing and constructed for the purpose of estimation of conservative fuel temperature. On the other hand, from the point of view of FP release behavior, more realistic fuel temperature estimation is required. In the present research, the realistic core-shape estimation model is constructed, and fuel temperature is estimated for reactor outlet coolant temperature 950C.