Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 76 Page 77 Page 78 Page 79 Page 80 Page 81 Page 82 Page 83 Page 84 Page 85 Page 86 Page 87 Page 88 Page 89 Page 90 Page 91 Page 92 Page 93 Page 94 Page 95 Page 96 Page 97 Page 98 Page 99 Page 100 Page 101 Page 102 Page 103 Page 104 Page 105 Page 106 Page 107 Page 108 Page 109 Page 110 Page 111 Page 112 Page 113 Page 114 Page 115 Page 116 Page 117 Page 118 Page 119 Page 120 Page 121 Page 122 Page 123 Page 124Nuclear Science User Facilities 90 Atom Probe Tomography of Fe-U-Pu-Zr Systems Assel Aitkaliyeva – Idaho National Laboratory – assel.aitkaliyeva@inl.gov Project Description The objectives of this work were to perform advanced characterization of fuel-cladding chemical interaction products and determine chemical composition of complex intermetallic phases formed between U-Pu-Zr fuels and Fe cladding upon exposure to high temperatures.This study investigated the interdiffusion between metal fuel and cladding via diffusion couple technique, formation of various intermetallic phases upon exposure to high tempera- tures, and fuel-cladding microstructural development at the atomic scale using the atom probe tomography (APT) technique in a local electrode atom probe (LEAP) instrument.The results allowed comprehensive 3-D analysis of the formed phases, which was not previously attainable due to the inherent difficulties associated with sample preparation. Implementation of focused ion beam technology allowed prepara- tion of site-specific lift-outs from the formed brittle fuel-cladding interaction layers with minimal hands-on sample processing, which allowed a thorough cross-sectional examination of all phases formed during annealing. Accomplishments Specimens were fabricated using focused ion beam at Electron Micros- copy Laboratory at INL and then analyzed in transmission electron microscope (TEM) and LEAP instru- ments.The goal of this project, to visualize the complex phases formed between U-Pu-Zr fuels and Fe clad- ding, has been achieved and success- fully incorporated into a publication in the Metallurgical and MaterialsTransactions E.A second manuscript is being prepared at this time. Future Activities The project is now complete. Publications and Presentations 1. Aitkaliyeva,A., J. Madden, B. Miller, C. Papesch, J. Cole, 2015, “Fuel-cladding interaction between U-Pu_Ze fuel and Fe,” Metall.Mater.Trans.E.,Vol. 2, No. 4, 2015, pp. 220–228. The results are amongst three known attempts to prepare transuranic- bearing nuclear fuels in the FIB and examine these fuels in TEM. This is a first-documented attempt to characterize this type of fuel in a LEAP instrument. Distributed Partnership at a Glance NSUF and Partners Facilities and Capabilities Center for Advanced Energy Studies Microscopy and Characterization Suite Idaho National Laboratory Electron Microscopy Laboratory Collaborators Idaho National Laboratory Assel Aitkaliyeva (principal investigator), Cynthia Papesch (collaborator)