Category Archives: Comprehensive nuclear materials

Filler particles

Filler-coke particles with good basal plane alignment were highly susceptible to microcracking along basal planes at low stresses. This cleavage was facilitated by the needle-like cracks that lay parallel to the basal planes and which were formed by anisotropic contraction of the filler-coke particles during the calcination process. Frequently, when a crack propa­gating through the binder phase encountered a well […]

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Vaporization

Vapor pressures have been established by Langmuir vaporization of C-saturated ZrC and by Knudsen effusion studies of ZrC in equilibrium with graphite. These are plotted in Figure 10. Langmuir studies are internally consistent, but give higher pressures than for the Knudsen method. Pollock37 and Coffman eta/.38 assumed the congruent evaporation composition

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Point defects created by radiation damage

The perturbations of the crystal lattice due to the displacement of atoms, that is point defects (intersti­tials, vacancies) and extended defects (defects clusters, dislocations, voids), contribute to the degradation of the thermal conductivity by scattering or limiting the mean free path of the phonons. This perturbation at the atomic scale is of the same nature as for soluble fission products […]

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Japan

Early in the 1960s, comprehensive R&D programs concerning MOX fuel were started in Japan and they resulted in the JAEA process that was adopted by the Plutonium Fuel Fabrication Facility (PFFF) which started operation in 1972. The PFFF used local control equipment to fabricate MOX fuel for the advanced thermal reactor FUGEN,63 and the experimental fast reactor JOYO on an […]

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Precipitation Behavior During Elevated Temperature Aging

Generally, austenitic stainless steels that have no 8-ferrite stay austenitic from room temperature up to about 550 °C, at which temperature they can start to experience the effects of thermal aging. Aging causes the alloy to decompose from a solid solution into various carbide or intermetallic precipitate phases and a more stable austenite phase. The decomposition of a quaternary Fe-Cr-Ni-Mo […]

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Damage Mechanisms

The basic damage phenomena in unidirectional com­posites under on-axis tensile loads involve multiple microcracks or cracks that form in the matrix perpen­dicular to fiber direction and that are arrested by the fibers by deflection in the fiber-matrix interface. In the composites reinforced with fabrics of fiber bundles, matrix damage is influenced by a multilength scale structure.39 Furthermore, 2D CVI SiC/SiC […]

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High pressures

The results presented earlier are valid only for the liquid phase and under condition that thermody­namic coefficients do not depend on pressure. In order to take into account the pressure dependence of the LM thermodynamic parameters, different thermal EOS were developed and applied to LM. Two main directions were followed with more suc­cess: the generalization of the well-known EOS of […]

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