In situ TEM study of temperature-induced fission product precipitation in UO2

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

“…These values are in good agreement with previously reported values [9,14,16]. Kashibe [16] observed the bubble size and density in low burnup spent fuel (23 MWd/kg) were 2 nm and 10 24 m -3 , which are comparable with present ion irradiation results.…”

“…Kashibe [16] observed the bubble size and density in low burnup spent fuel (23 MWd/kg) were 2 nm and 10 24 m -3 , which are comparable with present ion irradiation results. In addition, Xe bubbles which were 1.8±0.3 nm in size with a density of (4±2)x10 23 m -3 were found by Sabathier [9].…”

“…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.…”

TEM investigation of irradiation damage in single crystal CeO2

“…These features were identified as dislocation loops induced during the Ar ion-milling process, and had the same appearance as the loops produced by Kr ion irradiation. Such polishing damage might be removed by annealing at a high temperature ($1400°C) [15,16]. This step will be included in the future specimen preparation procedure.…”

Variable energy positron beam study of Xe-implanted uranium oxide

“…These noble fission gases have a low solubility in UO 2 and do not interact with it or with any other fission product, and, as a result, Xe segregates and forms bubbles [1,2], which have been observed as well in other materials [3][4][5][6]. The nucleation and diffusion of Xe bubbles in UO 2 have been studied by different experimental methods such as Electron Probe Micro Analysis (EPMA) [7], Secondary Ions Mass Spectroscopy (SIMS) [8], X-ray absorption spectroscopy (XAS) [9], and Transmission Electron Microscopy (TEM) [10][11][12]. One of the processes considered in modeling the fission gas release in UO 2 consists in intragranular bubble diffusion to the grain boundaries taking into account the precipitation of single atoms into intragranular bubbles accompanied by resolution of gas atoms.…”