Development and analysis of a metal‐fueled accelerator‐driven burner

The purpose of this paper is to compare the safety characteristics of an accelerator driven metal‐fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcriticality of the system. To accomplish this, an accelerator proton beam/tungsten neutron source model is surrounded by a subcritical blanket using metallic fuel and sodium as coolant. The consequences of typical accident transients, namely unprotected transient overpower (TOP), loss of heat sink (LOHS), and loss of flow (LOF) were calculated for the hybrid system and compared to corresponding results for a metal‐fueled fast reactor. Results indicate that the subcritical system exhibits superior performance for TOP (reactivity‐induced) transients; however, only in the critical system are reactivity feedbacks able to cause passive shutdown in the LOHS and LOF events. Therefore, for a full spectrum of accident initiators considered, the overall safety behavior of accelerator‐driven metal‐fueled systems can neither be concluded to be worse nor to be better than advanced reactor designs which rely on passive safety features.