scholarly journals Cementation of Bioproducts Generated from Biodegradation of Radioactive Cellulosic-Based Waste Simulates by Mushroom

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
S. B. Eskander ◽  
S. M. Abd El-Aziz ◽  
H. El-Sayaad ◽  
H. M. Saleh
Keyword(s):  
Radioactive Waste ◽  
Portland Cement ◽  
Current Work ◽  
Waste Form ◽  
Pleurotus Pulmonarius ◽  
Long Term Stability ◽  
Surrounding Environment ◽  
Solidified Waste ◽  
Physical And Chemical

The current work was devoted to study the solidification of bioproducts originated from the bioremediation of mixture of solid cellulose-based radioactive waste simulates using a mushroom (Pleurotus pulmonarius), in Portland cement. The obtained solidified waste form was subjected to mechanical integrity qualification after curing periods of 28 and 90 days. Chemical performance of the cement-waste form was also evaluated in different leachant media during 540 days. The results obtained gave useful information about the mechanical, physical, and chemical performances of the final cement-waste form incorporated the radioactive bioproducts. Moreover, it indicated that cement can provide a highly durable form that ensures a long-term stability of the solidified waste material and can act as a first barrier against the release of radiocontaminants from radioactive wastes to the surrounding environment.

Radiation Damage in Materials – Effects of Disorder

2009 ◽  
Vol 1193 ◽  
Author(s):  
Karl R. Whittle ◽  
Mark G. Blackford ◽  
Gregory R. Lumpkin ◽  
Katherine L. Smith ◽  
Nestor J. Zaluze
Keyword(s):  
Critical Temperature ◽  
Radiation Damage ◽  
Chemical Properties ◽  
Waste Form ◽  
Physical And Chemical Properties ◽  
Long Term Stability ◽  
Effects Of Disorder ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractRadiation damage and the effect on physical and chemical properties is an important component in the prediction of the long-term stability of waste form materials. As part of the ongoing goal of increasing the accuracy of long-term predictions of radiation damage, two types of material, based on proposed materials with a waste form application have been irradiated. Results have shown that Y2TiO5 (Y2.67Ti1.33O6.67), and Yb2TiO5 (Yb2.67Ti1.33O6.67), both of which are non-stoichiometric, disordered pyrochlore-based compounds, behave significantly different to the stoichiometric, ordered pyrochlore equivalent. For example the critical temperature, the temperature above which materials remain crystalline during irradiation, is found to decrease from the ordered equivalents, e.g. Y2Ti2O7. ⁡ A second material based on La2TiO5 has been found to behave differently to both La2/3TiO3 and La2Ti2O7, with a change in Tc of ∼ 200 K.

Long-term Stability of Oxygen Sensitive Membrane using Ruthenium Complex for Corrosion Monitoring of Radioactive-waste Repository

2019 ◽  
Vol 16 (11) ◽  
pp. 451-456
Author(s):  
Yuki Nakamura ◽  
Yusuke Koshiba ◽  
Daisuke Ito ◽  
Takashi Yokoyama ◽  
Shinji Okazaki ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Ruthenium Complex ◽  
Corrosion Monitoring ◽  
Radioactive Waste Repository ◽  
Term Stability ◽  
Long Term Stability ◽  
Oxygen Sensitive ◽  
Waste Repository ◽  
Sensitive Membrane

scholarly journals Bitumen Coating as a Tool for Improving the Porosity and Chemical Stability of Simulated Cement-Waste Forms

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
H. M. Saleh
Keyword(s):  
Experimental Tests ◽  
Waste Form ◽  
X Ray Diffraction ◽  
Microscope Examination ◽  
X Ray ◽  
Bitumen Emulsion ◽  
Waste Forms ◽  
Surrounding Environment ◽  
Simulated Waste ◽  
Physical And Chemical

Coating of simulated cement-based waste form was investigated by performing physical and chemical experimental tests. Moreover, X-ray diffraction, Fourier transform infrared spectroscopy, and electron microscope examination were applied on coated and noncoated simulated waste forms. Experimental results indicated that coating process improved the characterizations of cement-based waste form such as porosity and leachability. Diffusion coefficients and leach indecies of coated specimens were calculated and showed acceptable values. It could be stated that by coating cemented-waste form by bitumen emulsion, the radioactive contaminants were isolated, thus reducing the back release to surrounding environment during flooding by groundwater and consequently, saving the environment.

A Simplified Method to Assess the Risk of Geotechnical Engineering under Hydro-Chemical Corrosion

2011 ◽  
Vol 243-249 ◽  
pp. 2952-2957
Author(s):  
Peng Li ◽  
Guo He Li ◽  
Jian Liu
Keyword(s):  
Mechanical Properties ◽  
Chemical Kinetics ◽  
Geotechnical Engineering ◽  
Damage Index ◽  
Chemical Thermodynamic ◽  
Chemical Corrosion ◽  
Long Term Stability ◽  
Physical And Chemical ◽  
Reaction Direction

Rock mass are subject to continuous changes induced by physical and chemical processes of natural and anthropic origin. Such changes affect their mechanical properties. To quantitatively evaluate the hydro-chemical corrosion, the theories of chemical thermodynamic and chemical kinetics are introduced. An index was proposed, which provides a criterion to judge whether the corrosion would be happened and indicated the reaction direction. Then based on theoretical and testing results, a hydro-chemical damage index was proposed. And a series of damage degrees of sandstone under different circumstances, which consider the variations of pH values, temperatures, ions species and ions concentrations, were calculated by chemical kinetics method. Based on the results, the sensitivity of influencing factors was discussed. According to the calculation and the theory of poromechanics or testing results, the mechanical properties of geotechnical materials under hydro-chemical corrosion process can be predicted, so can assess the risk of geotechnical engineering long-term stability.

Glass/Water Reaction with and without Bentonite Present - Experiment and Model

1985 ◽  
Vol 50 ◽  
Author(s):  
B. Grambow ◽  
H. P. Hermansson ◽  
I. K. Björner ◽  
L. Werme
Keyword(s):  
Nuclear Waste ◽  
Water Permeability ◽  
Borosilicate Glass ◽  
Waste Form ◽  
Nuclear Waste Repository ◽  
Aqueous Environment ◽  
Long Term Stability ◽  
Chemical Effects ◽  
Waste Repository

In nuclear waste repository design bentonite has been included as part of the backfill for its sorbtive capacity and low water permeability. Nevertheless, it cannot keep the waste form dry once intrusion of groundwater has occured [1]. Leach experiments [2], [3] with the radioactive nuclear waste form borosilicate glass JSS-A have been performed with and without bentonite present to provide a database which allows the long term stability of the glass in aqueous environment to be forecasted and the chemical effects of bentonite to be studied.

Improving the Durability of Protective Materials Based on Inorganic Binders when Exposed to Short-Wave Radiation

2015 ◽  
Vol 725-726 ◽  
pp. 391-395 ◽  
Author(s):  
Oleg Makarevich ◽  
Olga Smirnova
Keyword(s):  
Radioactive Waste ◽  
Portland Cement ◽  
Short Wave ◽  
Wave Radiation ◽  
Optimal Composition ◽  
Short Wave Radiation ◽  
Long Term Storage ◽  
Term Storage

The concretes and mortars based on the Portland cement are able to perform the functions of the protective and durable materials for the disposal and long term storage of radioactive waste. It has investigated the influence of fineness of the carbon-containing component and the type of the water-reducing polycarboxylate-based admixtures on the properties of protective concrete of the recommended optimal composition.

A review of low-temperature H2S gas sensors: fabrication and mechanism

2021 ◽  
Author(s):  
Sara Ghaderahmadi ◽  
Milad Kamkar ◽  
Nishat Tasnim ◽  
Mohammad Arjmand ◽  
Mina Hoorfar
Keyword(s):  
Low Temperature ◽  
Power Consumption ◽  
Chemical Modification ◽  
Gas Sensors ◽  
Operating Temperature ◽  
Lower Power ◽  
Long Term Stability ◽  
Hazardous Gases ◽  
Physical And Chemical

Reduced detection temperature of hazardous gases such as H2S can lower power consumption and increase the long-term stability. The decreased operating temperature can be achieved via physical and chemical modification of the sensing layer.

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