b'Figure 2. Three welds for basic refabrication capability are shown. Two circumferential welds and a single seal weld completed under pressure.Accomplishments HFEF-compatible helium leak-check During FY2020, out of hot cellsystem which is used to perform postA new refabrication methodologies were establishedseal welding inspection.capability has been for performing bulk mechanicalFor mechanical defueling, thedeveloped to support defueling, fuel chemical dissolution,existing HFEF in-cell 3-axis end millfollow on irradiation rodlet end preparations for welding,was selected for use. An out-of-celland out of pile testing circumferential welding of end caps,demonstration was performed andof irradiated fuel.pressurized seal welding, and postidentified the need to develop a welding leak inspection. This includeddebris collection system to meet designing, fabricating and assemblingfacility requirements for collecting equipment hardware, equipmentand accounting for removed material. control systems, establishing opera- A vacuum system was developed for tional procedures, and performingthis purpose and is currently being out of cell functional and verificationfabricated. Once fabrication of the testing. In addition, basic facilityvacuum system is completed, an infrastructure needs were identifiedin-cell mechanical defueling demon-and in some cases necessary designstration can take place.was completed such as for a new hot cell wall penetration feedthrough toWet/chemical defueling utilizes an support the welding system poweracid bath to dissolve the fuel and and controls cables. In other cases,remove it from the cladding. This existing systems were identified andprocess uses 6M HNO3 heated to near restored to functionality such as the 2020|AFC ACCOMPLISHMENTS 15'