Review: The Effects of Radiation Chemistry on Solvent Extraction 4: Separation of the Trivalent Actinides and Considerations for Radiation-Resistant Solvent Systems

2010 ◽  
Vol 28 (4) ◽  
pp. 415-436 ◽  
Author(s):  
Bruce J. Mincher ◽  
Giuseppe Modolo ◽  
Stephen P. Mezyk
Keyword(s):  
Solvent Extraction ◽  
Radiation Chemistry ◽  
Trivalent Actinides ◽  
Radiation Resistant ◽  
Solvent Systems ◽  
Effects Of Radiation

scholarly journals To scavenge or not to scavenge, that is STILL the question

2012 ◽  
Vol 20 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Elizabeth G. Allan ◽  
Melissa C. Kander ◽  
Ian Carmichael ◽  
Elspeth F. Garman
Keyword(s):  
Crystal Size ◽  
Chemical Species ◽  
Absorbed Dose ◽  
Dose Dependence ◽  
Radiation Chemistry ◽  
X Ray ◽  
On Line ◽  
Crystallization Conditions ◽  
Effects Of Radiation ◽  
Dose Tolerance

An extensive radiation chemistry literature would suggest that the addition of certain radical scavengers might mitigate the effects of radiation damage during protein crystallography diffraction data collection. However, attempts to demonstrate and quantify such an amelioration and its dose dependence have not yielded consistent results, either at room temperature (RT) or 100 K. Here the information thus far available is summarized and reasons for this lack of quantitative success are identified. Firstly, several different metrics have been used to monitor and quantify the rate of damage, and, as shown here, these can give results which are in conflict regarding scavenger efficacy. In addition, significant variation in results from data collected from crystals treated in nominally the same way has been observed. Secondly, typical crystallization conditions contain substantial concentrations of chemical species which already interact strongly with some of the X-ray-induced radicals that the added scavengers are intended to intercept. These interactions are probed here by the complementary technique of on-line microspectrophotometry carried out on solutions and crystals held both at 100 K and RT, the latter enabled by the use of a beamline-mounted humidifying device. With the help of computational chemistry, attempts are made to assign some of the characteristic spectral features observed experimentally. A further source of uncertainty undoubtedly lies in the challenge of reliably measuring the parameters necessary for the accurate calculation of the absorbed dose (e.g.crystal size and shape, beam profile) and its distribution within the volume of the crystal (an issue addressed in detail in another article in this issue). While microspectrophotometry reveals that the production of various species can be quenched by the addition of scavengers, it is less clear that this observation can be translated into a significant gain in crystal dose tolerance for macromolecular crystallographers.

scholarly journals Solvent Extraction Studies for the Separation of Trivalent Actinides from Lanthanides with a Triazole-functionalized 1,10-phenanthroline Extractant

2020 ◽  
Vol 38 (7) ◽  
pp. 719-734 ◽  
Author(s):  
Peter Zsabka ◽  
Tomas Opsomer ◽  
Karen Van Hecke ◽  
Wim Dehaen ◽  
Andreas Wilden ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Trivalent Actinides

ChemInform Abstract: SEPARATION OF TRIVALENT ACTINIDES FROM LANTHANIDES BY SOLVENT EXTRACTION

1979 ◽  
Vol 10 (38) ◽  
Author(s):  
G. B. KASTING ◽  
E. K. HULET ◽  
J. A. HEPPERT ◽  
J. F. WILD
Keyword(s):  
Solvent Extraction ◽  
Trivalent Actinides

scholarly journals RADIATION RESISTANT BINDING MATERIALS BASED ON SILICATE ALUMOBARIUM CEMENTS

2020 ◽  
Vol 1 (154) ◽  
pp. 67-70
Author(s):  
N. Tsapko
Keyword(s):  
Physical And Mechanical Properties ◽  
High Strength ◽  
Technological Parameters ◽  
Protective Properties ◽  
Initial Strength ◽  
Radiation Resistant ◽  
Biological Protection ◽  
Effects Of Radiation ◽  
Main Components ◽  
High Degree

The article analyzes the possibility of developing custom binders with a set of set properties. Particular attention is paid to the development of radiation-resistant barium-containing cements based on aluminates and barium silicates. In order to normalize the radiation situation in Ukraine, it is urgent to develop structural materials with specified high protective properties against the effects of radiation, a high degree of biological protection in combination with high strength and fire resistance. The main components of the technological parameters of synthesis of the presented cements are determined. Test results of physical and mechanical properties of refractory radiation resistant cements are presented and general recommendations on the scope of the developed binder materials are given. It is determined that the resulting refractory cement can be used as a bond in the manufacture of special concretes and materials that have high protective properties while exposed to high temperatures and radiation. Thermal stability of concrete based on silicate alumobarium cement with different fillers was determined (cooling of the samples was carried out in air). As a result of the tests, it was found that all concrete specimens withstood more than 20 cycles (1000 ° C - air), while maintaining more than 80 % of the initial strength. These results confirm the known pattern: the higher the material density, the greater the material's ability to absorb radiation. Thus, the obtained data allow us to conclude that concrete based on silicate alumobarium cement have high absorption rates of brake radiation, which is more than 1.5 times higher than currently used concrete based on Portland cement. Therefore, it can be concluded that the concretes obtained are radiation resistant, with a high degree of attenuation of gamma rays and can be recommended as protective materials. Keywords: cement, composition, synthesis parameters, radiation resistance, property, strength

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