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New candidate materials for GenIV or fusion nuclear energy systems, e.g., nanostructured ferritic alloys, are distinguished from older-generation nuclear materials by much smaller feature sizes and complex local nanochemistry and crystallography. Established and perspective nuclear materials, e.g. reactor pressure vessel steels or plasma-facing tungsten, also form small nanoscale structures under in-reactor service. Here, we discuss recent advances in materials characterization – high-efficiency X-ray mapping combined with datamining; transmission Kikuchi diffraction; and atom probe tomography – that make it possible to quantitatively characterize these nanoscale structures in unprecedented detail, which enables advances in understanding and modelling of radiation service and degradation.

Jefferson Laboratory is developing a set of innovative superconducting magnets for the 12 GeV upgrade in JLAB Hall C. Here, we will report on the finite element analysis (FEA) of the force collar for the Super High Momentum Spectrometer Cosine Theta Dipole magnet. The force collar is designed with an interference fit and intended to provide enough pressure after cool down to operating temperature to counteract Lorentz forces acting on the dipole coil during operation. By counteracting the Lorentz forces and keeping the coil pack in overall compression, movement of the coils is expected to be minimized. The dimensional geometrymore » of the cold mass is maintained in the commercial solid modeling code UG/I-DEAS while the magnetic field design is maintained in the commercial TOSCA code from Vector Fields. The three dimensional FEA was conducted in the commercial codes ANSYS and IDEAS. The method for converting the models and calculating the loads transferred to the structure is discussed. The results show the cold mass response to: force collar assembly preload, differential thermal contraction, and operational Lorentz loads. Evaluations are made for two candidate force collar materials and two candidate force collar designs.« less

Advanced optical diagnostic techniques and instruments are being developed to operate successfully in the high-temperature coal combustion environments of large scale facilities. The success of these instruments depends heavily on maintaining a clear optical path into and out of the gas stream for long periods of time. The buildup of slag at the access port and contaminate fouling of the optical window require special systems to maintain the optical path. The rationale for, and design of, two such systems are presented in this article. The first system, a remotely operated window changer, provides for exchanging fouled windows for clean windows.more » The second system, a remotely operated slagbuster, provides for removing slag buildup in the access port. The design and operation of both systems are discussed. Parts lists, drawings, and schematics are presented also.« less

The authors discuss an investigation to determine analytically if the performance of concrete beams and columns in a hydrocarbon pool test fire would differ significantly from their performance in a standard test fire. The investigation consisted of a finite element analysis to obtain temperature distributions in typical cross sections, a comparison of the resulting temperature distribution in the cross section, and a strength analysis of a beam based on temperature distribution data. Results of the investigation are reported.