Safety implications of CLiFF liquid metal first walls

In this article we explore some of the safety issues associated with the Advanced Power Extraction (APEX) liquid metal first wall (FW) concept called the Convective Liquid Flow First Wall (CLiFF) design. In particular, we examine the chemical reactivity of and site boundary dose from three liquid metals being proposed for the CLiFF FW during a worst case confinement-boundary-bypass accident. The liquid metals considered are: lithium, tin, and gallium. The accident analyzed is a loss-of-vacuum accident (LOVA), during which air enters the CLiFF vacuum vessel (VV) from an adjoining room through a connecting diagnostic port or plasma-heating duct. The resulting lithium fire was analyzed and the energy released from this fire was found to be manageable for the CLiFF blanket design presently under consideration. The estimated dose at the site boundary is less than the no-evacuation limit of 10 mSv for ground level releases if plant isolation occurs within several hours.