Loading...
Search for:
chemical-durability
0.003 seconds
Study on Chemical Durability of Vitrified High Level Waste in Borosilicate Glass Matrix
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Sepehrian, Hamid (Supervisor) ; Yadollahi, Ali (Co-Supervisor)
Abstract
As nuclear energy continues to be used as a useful energy resource, waste management, especially management of high-level nuclear waste (HLW), will always be a major concern, as the future generations should not be deprived of the valuable benefits of this energy. Vitrification of liquid high-level radioactive waste (HLW) has received greater attention, worldwide, than any other high-level waste solidification process. The high solubility of HLW in borosilicate glass, the controllable temperature of this type of glass and its low leaching rate in repository environment, have introduced borosilicate glass as a suitable host for HLW immobilization. In this project, the immobilization of the...
Study on Immobilization of the Spent Ion Exchange Resins of Tehran Research Reactor in Borosilicate Glass
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Yadollahi, Ali (Supervisor) ; Sepehrian, Hamid (Co-Supervisor)
Abstract
Considering the operation of the current nuclear reactors and the country's policy to achieve 10,000 megawatts of nuclear power in the horizon of 1420, as well as the construction of research reactors, we will face a huge amount of radioactive waste in the coming years. Meanwhile, spent ion exchange resins constitute a large amount of low and intermediate level (LILW) solid radioactive waste produced from the nuclear industry. Therefore, appropriate precautionary measures should be taken for the immobilization and disposal of these radioactive wastes in order to ensure the sustainable development of the nuclear industry and the protection of the environment and human health. In this study,...
Mechanism of deleading of silicate glass by 0.5 N HNO3
, Article Journal of Non-Crystalline Solids ; Volume 355, Issue 48-49 , 2009 , Pages 2400-2404 ; 00223093 (ISSN) ; Rahimi, R. A ; Raisali, G ; Foruzanfar, F ; Sharif University of Technology
2009
Abstract
Mechanism of removal of lead from silicate glass containing 68.5 wt% PbO by 0.5 N HNO3 was investigated by incorporation of the chemical-analyses/weight-loss data into shrinking-core model (SCM) and minimization of the difference. Scanning electron microscopy (SEM), emission spectrometry with inductively coupled plasma (ICP), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS) were used to determine the compositional changes of the lead-silicate glass (LSG) samples. Dual inter-diffusion chemical reaction mechanisms having respective activation energies of 83.49 and 47.80 kJ/mol dominated the deleading process. © 2009 Elsevier B.V. All rights reserved
Chemical corrosion and gamma-ray attenuation properties of Zr and Ti containing lead silicate glasses
, Article Journal of Nuclear Materials ; Volume 385, Issue 3 , 2009 , Pages 527-532 ; 00223115 (ISSN) ; Raisali, G ; Sadrnezhaad, K ; Alipour, A ; Sharif University of Technology
2009
Abstract
Lead silicate glasses (LSGs) have high gamma-ray attenuation but low chemical durability properties. In this work, LSGs with (55.5-68.5 wt%) PbO content containing ZrO2 and TiO2 additions were produced. The chemical corrosion of various produced LSGs in 0.5 N HNO3 aqueous solution and determination of their gamma-ray attenuation coefficients for 60Co and 137Cs sources were investigated. The weight loss measurements, the SEM micrographs, the EDS analysis of the sample surfaces and the ICP analysis of solution were used to characterize the dissolution process. The effects of PbO content, ZrO2 and TiO2 additives on chemical corrosion, and also the effect of PbO on gamma-ray attenuation...
Chemical durability of metallic copper nanoparticles in silica thin films synthesized by sol-gel
, Article Journal of Physics D: Applied Physics ; Volume 41, Issue 23 , November , 2008 ; 00223727 (ISSN) ; Sharif University of Technology
2008
Abstract
In this study, chemical durability of metallic copper nanoparticles dispersed in sol-gel silica thin films was investigated by exposing the films to air after a reduction process. At first, heat treatment in air for 1 h produced silica films containing crystalline cupric oxide nanoparticles agglomerated on the film surface. Subsequently, reduction of the oxidized films in a reducing environment of N2-H2 for another 1 h at temperatures of 400, 500 and 600 °C resulted in the formation of crystalline metallic Cu nanoparticles diffused in the silica matrix. The time evolution of the surface plasmon resonance absorption peak of the reduced Cu nanoparticles was studied after the reduction...