scholarly journals Modern Sorption Materials for Cesium and Strontium Radionuclide Extraction from Liquid Radioactive Waste

2020 ◽  
Vol 13 (4) ◽  
pp. 80-89
Author(s):  
V. V. Milyutin ◽  
◽  
N. A. Nekrasova ◽  
V. O. Kaptakov ◽  
◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Liquid Radioactive Waste ◽  
Pilot Scale ◽  
Distribution Coefficients ◽  
Unbiased Manner ◽  
Radionuclide Composition ◽  
Materials Used ◽  
Experimental Values ◽  
Strontium Radionuclides ◽  
Sorption Characteristics

The paper describes the main types of sorption materials used to remove cesium and strontium radionuclides from low-level and intermediate-level liquid radioactive waste (LRW). It mainly focuses on sorbents produced at an industrial or pilot scale in Russia. Based on a developed standardized technique, it presents the experimental values for 137Cs and 90Sr distribution coefficients (Kd ) accounting for various types of sorbents. The study demonstrates that based on the developed technique, sorption characteristics of various types of sorption materials can be compared in an unbiased manner and most effective sorbents can be reasonably selected to treat liquid radioactive waste of various salt and radionuclide composition.

Experimental investigation on buffer/backfill materials for radioactive waste repository downward facing sorption additivity of cesium, strontium and cobalt with different concentrations

Kerntechnik ◽  
2021 ◽  
Vol 86 (5) ◽  
pp. 375-381
Author(s):  
C.-P. Lee ◽  
Y. Hu ◽  
Y. Sun ◽  
Y. Shi ◽  
N.-C. Tien ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Distribution Coefficients ◽  
Test Method ◽  
Radioactive Waste Disposal ◽  
Batch Test ◽  
Backfill Materials ◽  
Mixing Proportion ◽  
Synthetic Groundwater ◽  
Waste Repository ◽  
Sorption Characteristics

Abstract Buffer/backfill materials for radioactive waste disposal sites consist of pure bentonite or bentonite-rock mixtures. In this study, the batch test method was used to obtain the sorption characteristics of important radionuclides such as Cs, Sr and Co on buffer/backfill materials; i. e., mixing Wyoming MX-80 bentonite or local Taiwanese Zhi-Shin bentonite with possible host rock (argillite and granite) in different proportions (0∼100%). The distribution coefficients (Kd) for Cs, Sr and Co were obtained from the experiments. The distribution coefficient for the bentonite-rock mixtures were found, with more than 50% of mixing proportion of bentonite to argillite or granite, to have very similar values to that of pure bentonite. Furthermore, it was clearly found that the sorption of Cs, Sr and Co to bentonite-rock mixtures is decreased as ionic strength of the liquid phase is increased from 0.001M to 1M for NaCl solutions. According to the experimental results, in synthetic groundwater, it is quite convenient and helpful to assess the distribution coefficients (Kd) of Cs, Sr and Co for buffer/backfill materials using batch sorption experiments with bentonite-rock mixtures of fixed mixing proportions.

Sorption-Reagent Method in Liquid Radioactive Waste Management

2002 ◽  
Vol 713 ◽  
Author(s):  
Valentin A. Avramenko ◽  
Veniamin V. Zheleznov ◽  
Elena V. Kaplun ◽  
Dmitri V. Marinin ◽  
Tatiana A. Sokolnitskaya ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Reverse Osmosis ◽  
High Salinity ◽  
Liquid Radioactive Waste ◽  
Distribution Coefficients ◽  
Radioactive Waste Management ◽  
Combined Application ◽  
Multi Stage ◽  
Co Precipitation

ABSTRACTMethods of liquid radioactive waste (LRW) decontamination from radionuclides including their co-precipitation at specific conditions or adsorption on selective sorption materials are well known and extensively used in LRW management technologies. At the same time, it was shown in a number of papers that some forms of organic and inorganic ionexchangers react with solutions containing specific components that results in formation of virtually insoluble precipitates inside the sorbent matrix or on its surface. Here in some cases the sorbent selectivity to some radionuclides increases substantially.The sorption-reagent materials synthesized for decontamination purposes are the most highly selective in regard to such difficult to remove radionuclides as strontium-90 and cobalt-60. It was shown by comparative analysis of radionuclide removal efficiency by traditional selective sorbents and developed sorption-reagent materials that the latter have the highest distribution coefficients in systems too complex for “pure” sorption/ion-exchange decontamination. For example, the sorption-reagent materials have strontium distribution coefficients several dozens higher than those of commercially available sodium titanates and silicotitanates.The mechanism of radionuclide sorption on sorption-reagent materials of different types was studied. It was shown that this is a multi-stage process and the course of different stages of chemical reactions and sorption is determined by the parameters of medium from which radionuclides are sorbed. It was also shown that these materials application in liquid radioactive waste management enables one to develop simple technological setups combining the advantages of sorption and precipitation methods.One of the main fields of the sorption-reagent materials application can be decontamination of high-salinity radioactive waste formed whether as a result of ionexchanger filters regeneration in LRW management systems or in reverse osmosis installations. Use of sorption-reagent materials for high-salinity waste management enables one to reduce several ten-fold or even hundred-fold the volume of solid radioactive waste (SRW) to be sent for final disposal and, therefore, to decrease the cost of LRW management. The approach consisting in combined application of reverse-osmosis and sorption-reagent methods for LRW decontamination is suggested.

scholarly journals Seawater purification from cesium and strontium radionuclides

2019 ◽  
Author(s):  
Keyword(s):  
Sea Water ◽  
Liquid Radioactive Waste ◽  
Salt Content ◽  
Sorption Isotherms ◽  
Distribution Coefficients ◽  
Liquid Phases ◽  
Hydrated Zirconium Dioxide ◽  
Hydrated Zirconium ◽  
Strontium Radionuclides ◽  
Hydrated Titanium

The article deals with the study of sorption (under batch conditions) of cesium and strontium radionuclides from sea water with ferrocyanidic sorbents based on hydrated titanium and zirconium dioxides (Т-35, NPF-HTD), glauconite and clinoptilolite natural aluminum silicates (NPF-G, NPF-C), zirconium phosphate (Т-3А), modified hydrated zirconium dioxide (Т-3К), and manganese dioxide based on hydrated titanium dioxide (MD-HTD). We have obtained the sorption isotherms, defined the cesium and strontium distribution coefficients. Dependences of the cesium distribution coefficient by the sorbents in seawater saline content have been obtained. The authors recommend NPF-G and NPF-HTD sorbents for treatment of liquid radioactive waste based on seawater with various salt content. Coefficients of the cesium distribution between solid and liquid phases were 1,0∙105 and 1,0∙104 mg/l, respectively, even at solutions with the salt content of 100 g/l. In the process of strontium sorption from seawater, the strontium distribution coefficients do not exceed 1,9·102 ml/g, this is connected with big proportion (34±7 %) of stable colloidal forms of strontium in the simulated seawater.

Simulation of adsorption-coagulation purification of liquid radioactive waste to remove surfactants

2012 ◽  
Vol 85 (1) ◽  
pp. 46-51 ◽  
Author(s):  
M. G. Ivanets ◽  
T. A. Savitskaya ◽  
D. D. Grinshpan ◽  
N. G. Tsygankova ◽  
A. E. Savkin
Keyword(s):  
Radioactive Waste ◽  
Liquid Radioactive Waste

Immobilization of NPP evaporator bottom high salt-bearing liquid radioactive waste into struvite-based phosphate matrices

2021 ◽  
Vol 416 ◽  
pp. 125902
Author(s):  
Oleg A. Kononenko ◽  
Vitaly V. Milyutin ◽  
Vadim I. Makarenkov ◽  
Evgeny A. Kozlitin
Keyword(s):  
Radioactive Waste ◽  
Liquid Radioactive Waste ◽  
High Salt

scholarly journals Influence of Geopolymer Binder Components on Properties of Compounds during Cementation of Boron-Containing Liquid Radioactive Waste

2021 ◽  
Vol 21 (2) ◽  
pp. 71-77
Author(s):  
Yu. G. Fedorenko ◽  
◽  
Yu. A. Olkhovyk ◽  
A. N. Rozko ◽  
G. P. Pavlyshyn ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Liquid Glass ◽  
Potassium Hydroxide ◽  
Linear Equations ◽  
Liquid Radioactive Waste ◽  
Correlation Coefficients ◽  
Component Composition ◽  
Normative Values ◽  
Leaching Rate ◽  
Base Compound

The paper presents an analysis of the experimental results of the use of geopolymer binders for cementing boron-containing liquid radioactive waste (LRW). The dependence of the properties of compounds on the component composition of binders has been studied. The following components are considered: liquid glass with a silicon modulus of 2.9, a mixture of ash of Darnytsya TPP with slag of the Mariupol metallurgical plant in a ratio of 1: 1 and potassium hydroxide. To perform a factor analysis of the effect, the mass of these substances was taken as three factors in the analysis at two levels. For the manufacture of compounds imitation LRW was mixed with zeolite in a ratio of 10:1 at a temperature of about 60 оC. Subsequently, the above components were added to the mixture, the weight of which varied by ±17% relative to the weight of the base compound. To study the properties, samples of different sizes 5×5×5 cm, 1.5×1.5×1.5 cm and rectangular samples with an outer surface from 96 cm2 to 104 cm2 were made. Each property was studied in 8 samples. The obtained results allowed to construct linear equations that quantitatively link the corresponding characteristic of the compound with the composition of the binders. The correlation coefficients between the experimental and the data calculated by the equation are estimated. The average values of the correlation coefficients may indicate that not all factors were taken into account. The obtained regularities show that in the conditions of the experiment slag and ash increase, and liquid glass and potassium hydroxide reduce the rate of setting of the samples. The density of the samples is increased by ash and slag, while liquid glass and potassium hydroxide are reduced. The compressive strength of liquid glass and potassium hydroxide is reduced, while the mixture of ash and slag is increased. The leaching rate Сs of liquid glass and potassium hydroxide is increased, the mixture of ash and slag is reduced. At the same time, the leaching rate of Sr increases the ash/slag mixture, while liquid glass and potassium hydroxide decrease. The time during which the leaching of Cs reaches the normative values, slag and ash are reduced, and liquid glass and potassium hydroxide are lengthened. The obtained results can be taken into account when optimizing the composition of geopolymer binders for cementing LRW.

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