b'High Temperature Cladding Creep Performance of Cr-coated CladdingPrincipal Investigator: Mackenzie RidleyTeam Members/Collaborators: Samuel Bell, Danney Schappel, Dan Sweeney, Nathan CappsC r coated zirconium alloysbasis accidents. Specifically, this are considered nuclear fuelwork focused on LOCA scenarios, cladding candidates as anwhere fuel claddings are subject accident tolerant fuel cladding. Thisto rapid heating rates in steam is primarily due to the low neutronenvironments with a large absorption cross-section of Cr andpressure differential across the Zr, the excellent oxidation resistancecladding. The objectives were to of Cr, and the improved mechanicalutilize in situ strain measurements performance during postulatedin three dimensions to quantify accident conditions such as loss oftemperature and stress-dependent coolant accidents (LOCA). Yet, theparameters, relating to tempera-exact mechanism for the improve- ture and stress-dependent mecha-ments witnessed during LOCA isnisms for cladding deformation. not well understood. DevelopingSuch parameter development will a mechanistic understanding ofimprove understanding on why Cr cladding deformation during designcoatings, typically on the order of basis accidents is critical for accel- microns thick, show measurable erating the qualification of accidentdelays in cladding rupture until tolerant cladding materials and forhigher temperatures. Addition-improvement of modelling efforts.ally, this information will inform This work involved modificationsfuel cladding vendors on design of the Oak Ridge National Labora- space processes that are needed tory (ORNL) Severe Accident Testfor development of alternative Station (SATS) to enable capturecladding concepts with enhanced of cladding deformation duringrupture resistance during design simulated LOCA tests. Digitalbasis accidents. Deformation image correlation (DIC) was used toparameters will be used to inform monitor strain in situ, and posttestmodelling efforts, such as BISON, analysis provided insights on theso that qualification of accident mechanisms for deformation oftolerant fuel cladding candidates tubing under high pressures andcan occur more rapidly. Acceler-rapid temperature transients. ated qualification of advanced nuclear materials will increase the Project Description: competitiveness of nuclear power This work involved establishing ageneration through enhanced reliable DIC framework at ORNLsafety margin, opportunities for to investigate the reasons for theincreased fuel duty cycles, and known benefits of Cr coatingsopportunities for improved reactor during light water reactor design 112 2023|AFC ACCOMPLISHMENTS'