Advanced Sample Environments for In Situ Neutron Diffraction Studies of Nuclear Materials

Generation IV nuclear reactor concepts, such as the supercritical-water-cooled nuclear reactor (SCWR), are actively researched internationally. Operating conditions above the critical point of water (374˚C, 22.1 MPa) and fuel core temperature that potentially exceed 1850˚C put a high demand on the surrounding materials. For their safe application, it is essential to characterize and understand the material properties on an atomic scale such as crystal structure and grain orientation (texture) changes as a function of temperature and stress. This permits the refinement of models predicting the macroscopic behavior of the material. Neutron diffraction is a powerful tool in characterizing such crystallographic properties due to their deep penetration depth into condensed matter. This leads to the ability to study bulk material properties, as opposed to surface effects, and allows for complex sample environments to study e.g. the individual contributions of thermo-mechanical processing steps during manufacturing, operating or accident scenarios.. Authors: Reiche, Helmut Matthias [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); New Mexico State Univ., Las Cruces, NM (United States)]. DOE Contract: AC52-06NA25396. Subjects: Atomic & Molecular Physics(74); Condensed Matter Physics, Superconductivity & Superfluidity(75); Engineering(42); General Studies of Nuclear Reactors(22); Instrumentation Related to Nuclear Science & Technology(46); Materials Science(36); Nuclear Physics & Radiation Physics(73)