2017 | AFC ACCOMPLISHMENTS 133 The newly produced alloys were arc cast in much the same manner as previously, with the exception of the mold material.The original irradiation alloys were cast using a quartz mold, however, it has been found that a re-usable copper mold produces less waste, is more repeatable, and because molds are easily machined give greater diameter flexibility. Also, in some of the previous alloys, silicon contamination was found during the microstructural analysis, by using the copper molds silicon is removed from the process. Although copper contamination is also possible, due to its high thermal conductivity, and the large mass of the arc hearth and mold the copper is not heated to a high enough temperature to allow detrimental interactions with the mold and hearth. Previously, laser flash diffusivity samples have been cast using a 10-12 mm mold. However, this size of mold necessitates using large amount of limited TRU feedstocks, and is much larger than is needed for other characterization processes. Because of this it was decided that the FY17 characterization alloys would be cast at 5 mm diameter, which allow for additional laser flash analysis technique development. In this way a single casting batch can produced samples suitable for differential scanning calorimetry, microstructural analysis, chemical analysis, and laser flash analysis. The transmutation fuel package has supplied fuel samples for thermal and microstructural characterization of legacy AFC-1 and AFC-2 using recently recovered minor actinide feedstocks of americium and neptunium.