Nuclear Science User Facilities 50 reproduceability of testing that provides quantitative yield-strength values and a real-time look at deformation processes makes this an exciting technique.This specific project was to conduct micro-scale mechanical testing on annulus spacers irradiated at 180 and 300°C in service for approximately 14 and 19 equivalent full-power years to quantify differences in mechanical properties.This research supports efforts to make the micro-scale investigation and testing of nuclear core structural components more reproduceable, quantitative, and cost-effective by minimizing the use of hot cells and developing new in-situ small-scale mechanical testing techniques. Because these CANDU core components are nickel superalloys, they incur more pronounced radiation damage effects (increased displacement damage and helium and hydrogen content) and can be used as a predictive model for future effects that will occur in LWR structural materials. Accomplishments Large foils of active Inconel X-750 spacers were fabricated on the focused ion beam at the Materials Fuels Complex (MFC) in Idaho under the direction of Colin Judge and Cameron Howard, and shipped to the University of California Berkeley nuclear materials laboratory.This research was conducted primarily by Cameron Howard and facilitated in large part by staff at MFC, including microscopist James W . Madden, staff scientist Brandon D. Miller, and project director Collin J. Knight.These foils were subsequently sectioned into individual specimens and an in-situ lift‑out three-point bending test technique was developed Figure 2. (a) cross-section of an Inconel X-750 spring showing focused ion beam (FIB) milled foils of material taken from both edge and center regions (b) resulting bending beam structures cut into the large lift-out foil which has already been removed from the bulk spring (c) side view of a finished three-point bend specimen (d) top view of a completed three- point bend specimen.