Sorption of 137Cs, 90Sr, Se, 99Tc, 152(154)Eu, 239(240)Pu on fractured rocks of the Yeniseysky site (Nizhne-Kansky massif, Krasnoyarsk region, Russia)

Rozov, Konstantin; Rumynin, Vyacheslav G.; Nikulenkov, A. M.; Leskova, P.G.

doi:10.1016/j.jenvrad.2018.08.001

Cited by 17 publications

(4 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the clay microbial complex activity study, suspended clay samples (1 g) in penicillin vials were incubated in 10 mL of low-mineral liquid medium simulating the groundwater composition at the Yeniseisky site where a DGR storage facility is planned [37,38]. The medium composition was (mg/L): NaHCO 3 , 272; CaCl 2 , 71.8; MgSO 4 *7H 2 O, 70; pH 7.0; t = 20 • C. A mixture of sodium acetate, 1000 and glucose, 1000 was used as a carbon source for microbial stimulation.…”

Section: Model Experimentsmentioning

confidence: 99%

Characteristics and Rates of Microbial Processes in Clays of Different Mineral and Elemental Composition in Relation to Safety Prediction for ESB Clay Materials

et al. 2022

View full text Add to dashboard Cite

Microbial activity in clay barrier materials during radioactive waste disposal can lead to a violation of important physicochemical properties of the barrier system as a whole, thereby reducing the safety of the storage facility. This work evaluates the activity of the microbial complex of five bentonite and two kaolin clays. All clay materials were found to contain microorganisms, mostly with organotrophic aerobic and anaerobic metabolism capable of forming hydrogen sulfide and transforming basic and impurity clay minerals. The activity of microorganisms can increase with the ingress of degradation products of aluminophosphate matrices and cement barriers, as well as radiolysis products. For all clay the rates of microbial processes were shown to exhibit a direct correlation with the content of organic matter, kaolinite, and potassium feldspar, and an inverse correlation with montmorillonite content. A systematic methodological approach is proposed for clay materials and their susceptibility to microbial processes. The approach makes it possible, based on the content of organic matter, biophilic elements in the samples, parameters of the respiratory activity of the microbial complex, the formation of hydrogen sulfide, and other parameters, to assess in advance the possibility of using them in barriers.

show abstract

Section: Model Experimentsmentioning

confidence: 99%

Characteristics and Rates of Microbial Processes in Clays of Different Mineral and Elemental Composition in Relation to Safety Prediction for ESB Clay Materials

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Solutions simulating the underground natural water of the "Yeniseisky" site [18] and containing one of the studied radionuclides (Cs-137, Sr-90 or Am-241) were prepared for sorption experiments, both on the whole fractured sample R-11 and on the crushed samples of mineral phases. The radionuclide concentration in the solution without carriers was 10 −9 mol L −1 , that corresponds to the initial activity of Cs-137, Sr-90 or Am-241 in solution 430, 285, 15 Bq mL −1 , respectively.…”

Section: Characterization Of the Model Water Solutionmentioning

confidence: 99%

“…The sorption properties of the crushed samples of the fracture filler material of the Nizhnekansky granitoid massif with respect to Cs, Sr, Se, Tc and Eu were studied in the work [18]. It was established that the highest sorption activity towards Cs, Eu and Pu demonstrate rocks from the contact zone of gneisses and dolerites, with distribution coefficients about 10 3 mL•g −1 .…”

Section: Introductionmentioning

confidence: 99%

Sorption and Spatial Distribution of 137Cs, 90Sr and 241Am on Mineral Phases of Fractured Rocks of Nizhnekansky Granitoid Massif

et al. 2022

View full text Add to dashboard Cite

The sorption behavior and spatial microdistribution of Cs-137, Sr-90 and Am-241 onto the surface of a fractured rock sample from the R-11 borehole of the exocontact zone of the Nizhnekansky granitoid massif were studied. The sorption efficiency of the fractured sample increases in the row of Sr < Cs < Am, where americium is the most retained radionuclide. Based on the image processing of radiograms and scanning electron microscopy data, the mineral relative sorption efficiency (RSE) values were determined to quantify the contribution of the mineral phases of the fractured sample to radionuclide retention. It was established that cesium and strontium are predominantly retained in cracks filled with secondary mineral chlorite. Zeolite is a less effective sorbent with respect to cesium and strontium. Americium sorption is uniform over the whole surface of the fractured sample, with close RSE values for all mineral phases (RSE ~1). The behavior of cesium in heterogeneous and monomineral systems of crushed mineral phases of quartz, biotite and zeolite NaA imitating minerals of the fractured rock sample R-11 was determined. It was shown that the fraction of the sorbed cesium in a heterogeneous system of two mineral phases—biotite and quartz—was larger than the sum of sorption values for the same separated mineral phases. Based on the models of radionuclide sorption on illite–smectite minerals, it was able to estimate the depth of the penetration of solution into the fractured rock sample R-11. The variations of penetration depths for solutions of specific radionuclide into the fractured rock sample were established.

show abstract

“…Since no reliable data currently exists on the composition of the groundwater of the Yeniseyskiy Site at the target depth, synthetic groundwater (hereafter referred to as SGW) was used in the experiments and developed based on available hydrogeological data and data in [19], which is characterized by a pH of 8.1, ionic strength of 6.5 mmol/L, and ionic composition: Na + -0.760, Mg 2+ -0.494, Ca 2+ -1.217, K + -0.115, Cl − -2.549, SO 4 2− -0.494, and HCO 3 − -0.76 mmol/L. Compacted bentonite specimens were allowed to saturate by absorbing SGW from burettes connected to inlets at cell bases to let trapped air escape through outlets at cell tops for 28 days, then to inlets at cell tops for 87 days to reach the most homogeneous saturation of bentonite possible (Figure 1b).…”

Section: Experiments and Conditionsmentioning

confidence: 99%

Swelling Pressure and Permeability of Compacted Bentonite from 10th Khutor Deposit (Russia)

2021

View full text Add to dashboard Cite

Bentonites from the 10th Khutor deposit (Republic of Khakassia, Russia) are considered a potential buffer material for isolation of radioactive waste in the crystalline rocks of Yeniseyskiy site (Krasnoyarskiy region). This study presents the results of a series of permeameter experiments with bentonite compacted to dry densities of 1.4, 1.6, and 1.8 g/cm3, saturated and permeated by the artificial groundwater from Yeniseyskiy Site. Permeation was conducted at hydraulic gradients of 180–80,000 m/m to simulate potential hydraulic conditions in the early post-closure phase of a deep geological repository (DGR). The respective swelling pressures of 0.8 ± 0.3, 2.2 ± 0.6, and 6.3 ± 0.3 MPa and permeabilities of (27 ± 15) × 10−20, (3.4 ± 0.8) × 10−20, and (0.96 ± 0.26) × 10−20 m2 were observed for the hydraulic gradient of 2000 m/m, which is recommended for the determination of undisturbed swelling pressures and permeabilities in permeameter experiments. Upon incremental increases in the hydraulic gradient, swelling pressures at all densities and permeability at the density of 1.8 g/cm3 remained unchanged, whereas permeabilities at 1.4 and 1.6 g/cm3 decreased overall by a factor of approximately 5 and 1.7, respectively. Seepage-induced consolidation and/or reorganisation of bentonite microstructure are considered possible reasons for these decreases.

show abstract

Sorption of 137Cs, 90Sr, Se, 99Tc, 152(154)Eu, 239(240)Pu on fractured rocks of the Yeniseysky site (Nizhne-Kansky massif, Krasnoyarsk region, Russia)

Cited by 17 publications

References 17 publications

Characteristics and Rates of Microbial Processes in Clays of Different Mineral and Elemental Composition in Relation to Safety Prediction for ESB Clay Materials

Characteristics and Rates of Microbial Processes in Clays of Different Mineral and Elemental Composition in Relation to Safety Prediction for ESB Clay Materials

Sorption and Spatial Distribution of 137Cs, 90Sr and 241Am on Mineral Phases of Fractured Rocks of Nizhnekansky Granitoid Massif

Swelling Pressure and Permeability of Compacted Bentonite from 10th Khutor Deposit (Russia)

Contact Info

Product

Resources

About