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 50 This project is a collaborative effort between the Idaho National Laboratory (INL), Savannah River National Labora- tory, and Drexel University aiming to explore the neutron irradiation response of MAX phases (i.e., Ti3SiC2 andTi3AlC2) for advanced nuclear applications. Samples of each composition were irradiated in the AdvancedTest Reactor (ATR), with nominal irradiation conditions of 0.1, 1, and 9 dpa at 100, 500, and 1000°C. Post-irradiation examina- tion was performed at the Center for Advanced Energy Studies, including X-ray diffraction (XRD), scanning electron microscope (SEM), transmis- sion electron microscope (TEM), and resistivity testing. Project Description Robust materials are critical to meet evolving advanced reactor and fuel designs.These materials need to operate in extreme environments of elevated temperatures, corrosive media, and high-radiation fluences, with lifetime expectation of greater than 60 years. Full understanding of a material’s response to irradiation is paramount to long‑term, reliable service.The layered ternary carbides and nitrides, known as MAX phases, have the potential to be used in the next‑generation nuclear reactors.All MAX phases are fully machinable even though some of them, such asTi3SiC2 andTi3AlC2, are similar to titanium metal in density, but are three times as stiff.The thermal and electrical conductivities are high and metal-like. They have relatively high-fracture toughness values and some are chemi- cally stable in corrosive environments. They also have shown irradiation damage tolerance in heavy ion studies. The aim of this project is to investi- gate the damage inTi3SiC2,Ti3AlC2, and chemical vapor deposition SiC (for comparison) after exposure to a spectrum of neutron irradiations consistent with conditions found in light water nuclear reactors.The carbides are exposed to a series of neutron fluence levels (0.1, 1, and 9 dpa) at moderate to high irradiation temperatures (100, 500, and 1000°C) in the ATR at INL.The damage to the microstructures and the effects of the radiation on the mechanical and Advanced Damage-Tolerant Ceramics: Candidates for Nuclear Structural Applications Michel W. Barsoum – Drexel University – barsoumw@drexel.edu The MAX phases, a class of machinable, layered, ternary carbides, and nitrides, have great promise for use in the next‑generation of nuclear reactors. This is the first time the MAX phases have been neutron irradiated at temperatures as high as those carried out here.