Category Archives: Comprehensive nuclear materials

Role of Solute Segregation and Precipitation

Solute atoms of importance include elements origi­nally added to the material during fabrication and species produced by nuclear transmutation reactions (e. g., He and H, and a range of other elements). Solute atoms may exhibit preferential coupling with point defects created during irradiation, leading to either enhancement or depletion of solutes at point defect sink structures such as dislocations, grain […]

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He Energetics and He-Defect Complex Interactions

The results of atomistic modeling of He-defect inter­action energies are presented in this section for both ab initio and MD and molecular statics (MS) meth­ods. The ab initio results provide interaction energies 0 K that can be used in Monte Carlo simulations that are generally restricted to very small, nonequilib­rium, high-pressure (solid) He-vacancy (V) clusters. This contrasts with the models […]

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Electronic Defects

1.02.4.1 Formation Electronic defects are formed when single or small groups of atoms in a crystal have their electronic structure changed (e. g., electrons removed, added, or excited). In particular, they are formed when an electron is excited from its ground state configuration into a higher energy state. Most often this involves a valence electron, although electrons from inner orbits […]

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Dislocation Channeling and Flow Localization

Mechanical deformation of metals and alloys after irradiation at temperatures below recovery Stage V produces deformation microstructures that typically evolve from predominantly dislocation cell micro­structures in the unirradiated and low-dose irradiated conditions to a variety of localized deformation microstructures above a threshold damage level including twinning, planar dislocation deformation, and formation of dislocation channels.314-316 Forma­tion of cleared dislocation channels has […]

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Radiation Effects in Other Ceramics

Numerous additional ceramics have been either used or proposed for nuclear reactor materials applica­tions. These include graphite (discussed in other chapters in this volume) as well as carbides and nitrides, such as ZrC and ZrN, which have higher thermal conductivities than their sister oxide com­pound, ZrO2. Research into the radiation damage properties of these materials is in its infancy, and […]

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