An analytical study of gas-bubble nucleation mechanisms in uranium-alloy nuclear fuel at high temperature

Fundamental Studies of Irradiation-Induced Defect Formation and Fission Product Dynamics in Oxide Fuels

“…The gas in solution needs to reach a critical value before a multi-atom nucleation process can occur. At higher temperatures, this dynamic solubility limit is reduced so that the nucleation occurs at a lower dose [15]. This result is confirmed by previous studies of gas atom precipitation conditions.…”

“…At the final dose of 5x10 15 ions/cm 2 (figure 2.2 (a7)), in addition to the similar dislocation line structure, small individual dislocation loops could still be distinguished.…”

“…This result is confirmed by previous studies of gas atom precipitation conditions. Evans [14] reported that no visible bubbles were found below 400°C in irradiation of 200 keV Kr in UO 2 for the dose of 5x10 15 ions/cm 2 . More recently, Sabathier [9] found Xe bubbles in UO 2 at 1x10 16 ions/cm 2 after annealing to 670 K.…”

“…The expanding of loop size leads to interaction of dislocation loops at higher doses, which started from the dose of 3x10 15 ions/cm 2 (figure 2.2 (a6)) at 600°C and 8x10 14 ions/cm 2 (figure 2.2 (b4)) at 800°C. The dislocation loops then developed into line structure as shown in figure 2.2 (b6), and slowly aggregated to form dislocation networks by climb motion (figure 2.2 (b7)).…”

The effect of lattice and grain boundary diffusion on the redistribution of Xe in metallic nuclear fuels: Implications for the use of ion implantation to study fission-gas-bubble nucleation mechanisms

“…Understanding of nucleation, growth, and coalescence of fission-gas bubbles in metallic fuels is an essential element of a predictive capability. Recently, Rest proposed a multi-atom gas-bubble-nucleation mechanism in a uranium-alloy nuclear fuel operating in the high-temperature equilibrium c-phase [1]. This is in contrast to the conventional two-atom bubble-nucleation mechanism [2,3].…”