b'4.3 REFABRICATION OF FUEL RODS FOR FOLLOW-ON TESTINGRefabrication of Fuel Rods for Follow-On TestingPrincipal Investigator: Jason SchulthessTeam Members/ Collaborators: Justin Yarrington, Spencer Parker, Joe Palmer, James Zillinger, Clayton Turner, Connor Woolum, Mark Cole Advanced refabricationI rradiated fuel rod refabricationcapability and benchmarking is a crucial enabling capabilityagainst capabilities that had been that bridges between base reactorpreviously available at the Halden capability will supportirradiation and subsequent experi- reactor project. Specific objectives using instrumented fuelmentation and/or re-irradiation. Itincluded performing evaluations rodlets in follow is key to performing meaningfulof the Halden drilling and welding on experiments. research and development (R&D)modulus using surrogate materials, on fuels with any level of burnup,evaluating the potential engineering especially at the Transient Reactorneeds and facility requirements for Test (TREAT) Facility and opens theestablishing a cryogenically cooled door to R&D for materials tested infuel drilling system in a hot cell commercial nuclear power plants.environment, evaluating alternative Refabrication allows access to fuelfuel drilling methods that do not at any point in its lifetime, allowingrequire cryogenically cooling the opportunity to apply instrumentation fuel, and options for remotely and perform experiments to measurewelding/attaching thermocouples performance under a variety ofto the outer surface of fuel cladding specified conditions. Secondly, theboth in the remote environment ability to repackage previouslyand in a manner compatible with irradiated fuel into experimentthe current design of the transient vehicles is an enabling capabilitywater irradiation system for TREAT that ensures experiments are(TWIST) irradiation device. These instrumented and contain desiredadvanced refabrication capabilities boundary conditions for experimentare necessary to support experiments objectives. Measurements on highusing highly instrumented rodlets.burnup fuels are impractical, if not impossible, without refabricationAccomplishmentsand experiment preparation capability. Halden had developed separate defueling, fuel drilling and welding Project Description modules over the course of thirty+ Basic refabrication capabilityyears of refabrication development. was established in FY2021 andTo rapidly gain experience with included the ability to section rods,refabrication, Idaho National Labora-defuel the ends to create spacetory (INL) procured a defueling, fuel for new end caps, weld new enddrilling and welding module from caps in place, and finally seal weldHalden. The Halden fuel drilling under pressure and leak check.module utilizes a cryogenic system Objectives in FY2022 includedto stabilize the fuel during drilling evaluation of advanced refabricationoperations, while the welding 148 2022|AFC ACCOMPLISHMENTS'