b'1.3 SHOWCASE CAPABILITIESIrradiated Fuel Rod RefabricationPrincipal Investigator: Jason SchulthessTeam Members/ Collaborator: Spencer Parker, Evans Chambers, Jordan Argyle, Kim Davies, Mark Cole,Colby Jensen, Cad Christensen and Gene MatrangaI rradiated fuel rod refabricationrication capability includes segmenting is a crucial enabling capabilityfull length fuel rods, defueling the that bridges between base reactorends to make space for new end caps, irradiation and subsequent experi- attaching and welding in place new mentation and/or re-irradiation.end caps, and pressurizing and seal It is key to performing meaningfulwelding the new rods, followed by leak research and development (R&D)check inspection, which are then avail-on fuels with any level of burnup,able for follow on irradiation or out of especially at the Transient Reactorpile testing. Installation of the basic fuel Test (TREAT) Facility, and opens therod refabrication system is planned for door to R&D for materials tested infiscal year (FY) 2021. commercial nuclear power plants.The basic refabrication welding Several industry-led projects alreadysystems have been designed to provide exist that are dependent uponmaximum flexibility and reliability refabrication capability to generateto perform the three necessary welds. data to support licensing for AccidentTwo circumferential welds to attach the Tolerant Fuels (ATF) and extensionend caps, and one seal weld to ensure of fuel burnup limits. Refabricationhermeticity of the rodlet. All three allows access to fuel at any point inwelds are performed using commer-its lifetime, allowing opportunity tocially established micro-Tungsten Inert apply instrumentation and performGas (TIG) welding methodology. The experiments to measure performancecircumferential welds are performed under a variety of specified condi- using a custom designed welding lathe, tions. Measurements on high burnupwhich holds the welding torch in a fuels are impractical, if not impos- single position and rotates the rodlet, sible, without refabrication capability. which provides the most consistent Project Description: welding on these materials. The Figure 1. Out of cell demonstration ofA fuel refabrication system has beenlathe system further incorporates an rodlet end preparations for welding,designed and constructed to beautomated variable voltage controller, specifically, removal of the exteriorinstalled in the Hot Fuel Examinationwhich supports consistent welds if the oxide layer for welding. Facility (HFEF) hot cell to enable basicrods are found to be non-circular (e.g., fuel rod refabrication. The basic systemelliptical). The seal welding system also will include limited options to rein- utilizes micro-TIG methodology and strument irradiated fuel, which isencapsulates the rodlet in a pressurized currently planned as an advanced refab- chamber capable of pressurizing the rication and reinstrumentation systemrodlet from 500 psi to 2250 psi to to work in concert with the basicallow for experiments to be conducted refabrication capability. The basic refab- with variable rodlet internal pressures.14 2020|AFC ACCOMPLISHMENTS'