b'Figure 2. Machined annular fuel pin. of overheating the fuel and cuttingsuccessfully performed on a 0.75 tool during the machining process,long, 0.192 outer diameter slug of machine oil was used to cool theU-20Pu-10Zr fuel using a 0.116 drill machined surface. First the fuel slugbit to create an annular fuel pin with was held in place and turned downlittle under 65% smear density. Figure using the lathe attachment in order2 shows the machined annular slug. to reduce its diameter and also toIt was found during this process that smooth the surface. The fuel was thenthe machine oil was not necessary to held in place while a drill bit waskeep the materials from overheating. used to hollow out the center andThe second geometry machined was a create an annular geometry. Machineclover leaf. This geometry requires oil was applied liberally to the drillthat slots be machined down the bit each time it was removed fromlength of the fuel pin to allow space the center of the fuel rod. This wasfor swelling and heat transfer without 168 2019|AFC ACCOMPLISHMENTS'