Radiation-Induced Changes in Quartz, A Mineral Analog of Nuclear Power Plant Concrete Aggregates

Abstract

Quartz single-crystal samples consisting of α-quartz crystal structure were neutron irradiated to fluences of 5 × 10, 4 × 10, and 2 × 10 n/cm (E > 0.1 MeV) at two temperatures (52 and 95 °C). The changes in the α-quartz phase as a function of these two conditions (temperature and fluence) were studied using X-ray powder diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM), and the results acquired using these complementary techniques are presented in a single place for the first time. XRD studies showed that the lattice parameters of α-quartz increased with increasing neutron flux. The lattice growth was larger for the samples that were neutron irradiated at 52 °C than at 95 °C. Moreover, an amorphous content was determined in the quartz samples neutron irradiated at 4 × 10 n/cm, with the greater amount being in the 52 °C irradiated sample. Complete amorphization of quartz was observed at a fluence of 2 × 10 n/cm (E > 0.1 MeV) using XRD and confirmed by TEM characterization and Raman spectroscopic studies. The cause for α-quartz lattice expansion and sample amorphization was also explored using XRD and Raman spectroscopic studies.

Thermochromatographic behavior of iodine in fused silica columns when evaporated from lead–bismuth eutectic

“…These relations can be used to identify the molecular species of iodine occurring in the experiments. Additionally due to chemical similarities, the choice of fused silica as an adsorbent gives information regarding the iodine behavior on concrete, a major structural component in nuclear reactors [16].…”

Irradiation-induced damage in concrete-forming aggregates: revisiting literature data through micromechanics

“…This leads to atomic bonds stretching and eventually breaking [10,11]. Cumulated defects result in macroscopic change of the physical [4,[12][13][14], chemical [15][16][17], and mechanical properties of irradiated minerals [18][19][20]. Most silicate-bearing minerals, metal-bearing oxides, and to a lesser extent, carbonated minerals of initial pristine crystalline structures experience RIVE as a density decrease caused by irradiationinduced amorphization, which is also called metamictization [21].…”

Raman characterization of phonon confinement and strain effects from latent ion tracks in α‐quartz

“…The higher the ion fluence, the smaller the areal fraction of defect-free crystalline material. [20,21,32,[59][60][61] It should be noted, however, that even up to fluences of 1 Â 10 11 ions cm À2 , no amorphous background was observed. This suggests that the actual areal fraction of amorphous or glassy material is below detection limits and that the observed changes in line shape are more likely due to the phonon confinement effect.…”