b'on each weld TC junction, when done on an oxidized sample, will work for removing the oxide layer at a TC junction point reducing porosity in the weld. A total of 5 different jigs were fabricated and experimented with. The final configuration, called Jig revision 5 (see Figure 3), added a second linear guide to square up the heat sinks. This helped improve contact surface of the heat sink to the clad-ding to ensure welds were more consistent. Three TC wire sets were loaded into the jig resulting in three successful welds with satisfactory results on wash up and color. Figure 4 shows the results of one of the three welds.Figure 2. Out-of-cell welding systemwas fabricated and tested out-of-Refined dry drilling techniques of with first jig iteration cell. Figure 2 shows the out-of-cellUO 2pellets utilizing the existing welding system with the firstHot Fuel Examination Facility iteration of the TC holder jig inside(HFEF) mini-mill equipment. The the chuck. Initially, each weld wasbasic refabrication steps were attempted with a single arc. Afterdemonstrated in fiscal year (FY)21 adding heat, the results producedinside the HFEF. These steps (see the necessary burn back to cutFigure 5) included sectioning, defu-the wire free from the jig, howevereling a section of an irradiated fuel the wire tended to ball up at thepin for a new spacer, wave springs, base of the heat sink. If the currentdrilling, and end caps welding. was increased to get the properDuring refabrication, a carbide washup, a substantial divot inendmill was used and able to drill the weld was produced. Furtherthrough the fuel. A continuation experimentation utilized runningof this research was performed a lower current on two welds onto demonstrate more advanced each wire. The first weld would cutrefabrication on surrogate and pre-the wire free from the heat sinkirradiated fuel pins. These refab-and the second weld would washrication steps included defueling, the wire end into the puddle. Itdrilling a centerline hole in the fuel, was observed in previous circum- supporting the hole with a molyb-ferential welds with end caps ondenum tube, and enabling the an oxidized part, that when properinsertion of a thermocouple down gas coverage was provided, thethe centerline of the fuel to monitor oxide layer at and next to the weldthe temperature during further was eliminated/reduced. Basedresearch. In FY23, there were three on these results, its anticipatedprimary refabrication processes that the first arc strike on setupresearched and experimented on.206 2023|AFC ACCOMPLISHMENTS'