b'Figure 2. Prototypic FAST fuel slugs casting using the pressure differential assisted gravity casting technique.Figure 1. Mockup hardware for the FAST irradiation test to be used in the ATR outboard A and Small I positions.Accomplishments: The first step in showing feasibility of fabricating the FAST test was to cast surrogate fuel slugs in a manner that could consistently produce acceptable slugs. Nearly all of the previous AFC metallic fuel tests were cast using an arc casting technique. In arc castingnon-consistent during casting and is the fuel is heated by means of anseen as a large schedule risk. This risk electric arc to a temperature aboveis greatly compounded by the small the melting point, after which thesize of the FAST samples. To mitigate fuel flows into the mold. Although,this risk, modifications were made to this method has been used almostthe arc melting apparatus which will extensively for the AFC tests it can beforce the molten fuel into the mold 2019|AFC ACCOMPLISHMENTS 173'