Papers by Keyword: Fusion Energy

Abstract: The first wall material in a nuclear fusion reactor endures a series of complex processes, resulting in irradiation damage of its structural materials and eventually questioning its operative safety. Experimental and computer simulation are currently applied to search for irradiation damage. We used, the Material Studio software to model and calculate the crystal structure and mechanical properties, and the CASTEP module, primitive cell of iron, Fe-Cr alloy and Fe-Cr alloy with defects to calculate, analyze, and obtain the values of elastic constants and Young’s modulus. Our results showed that addition of Cr atom to conventional first wall metal materials of nuclear reactor, enhanced endurance by increasing the values of elastic constant and Young’s modulus, but distorted the symmetry of the crystal structure. We preliminarily prove and predict the possibility of the changes of mechanical properties of Low-activation martensite/ferrite under irradiation effects.

Abstract: This study deals with the low cycle fatigue (LCF) behaviour of two steels strengthened by oxide dispersion. The ODS Eurofer steel shows cyclic softening, slower than in the case of the same steel without oxide particles. The 14Cr ODS ferritic steel is cyclically stable, even a slight cyclic hardening is observed at 650 °C. The reasons for this different behaviour lie probably in the less resistant matrix with a lot of weak subgrain boundaries in ODS Eurofer, because no clear difference in the oxide particles distribution was found.

Abstract: Lithium-based ceramics have been recognized as promising tritium breeding-materials for D-T fusion reactor blankets. Lithium silicates, Li4SiO4 and Li2SiO3, are recommended by many ITER research teams as the first selection for the solid tritium breeder. The solid-state reaction method is the most important way to synthesize lithium silicates. In present study, the processes of solid-sate reaction between amorphous silica and Li2CO3 powders was investigaed by TGA/DSC; the lithium silicate powders were synthesized at 700~900°C with different Li:Si molar ratio using solid-state reaction method. The optimized synthesis temperature and the solid-state reaction mechanism were derived on the base of experimental results.

Abstract: Planning for a U.S. test blanket module to operate in the internationally-sponsored ITER reactor has focused attention on the many coating and compatibility issues that will need to be solved before fusion energy moves from concept to commercial reality. Examples are given for (1) a dual-layer, electrically-resistant coating as a potential solution to reduce the magnetohydrodynamic pressure drop with liquid Li and (2) materials compatibility issues with eutectic Pb-Li for conventional alloys and SiC/SiC composites. Because of the reduced activity of Li in Pb-Li, a wider range of functional materials can be considered in this system. Nevertheless, an Al2O3 scale on FeCrAl was transformed to LiAlO2 after exposure to Pb-Li at 800°C.

Abstract: Ceramic matrix composites (CMC’s), particularly silicon carbide (SiC) fiber-reinforced SiC-matrix (SiC/SiC) composites, have been studied for advanced nuclear energy applications for more than a decade. The perceived potentials for advanced SiC/SiC composites include the ability to operate at temperature regimes much higher than heat-resistant alloys, the inherent low inducedactivation nuclear properties, and the tolerance against neutron irradiation at high temperatures. This paper reviews the recent research and development of the advanced radiation-resistant SiC/SiC composites for nuclear applications. Additionally, remaining general and specific technical issues for SiC/SiC composites for nuclear applications are discussed.