Leaching of 137Cs from Chernobyl fuel debris: corium and “lava”

2019 ◽  
Vol 107 (12) ◽  
pp. 1155-1160 ◽  
Author(s):  
Bella Yu. Zubekhina ◽  
Boris E. Burakov ◽  
Oksana G. Bogdanova ◽  
Yuriy Yu. Petrov
Keyword(s):  
Mass Loss ◽  
Quantitative Data ◽  
Specific Activity ◽  
Chemical Durability ◽  
Distilled Water ◽  
Leach Test ◽  
Simulated Seawater

Abstract Samples of Chernobyl fuel debris such as corium and “lava” had been studied using repeated static leach test MCC-1 at temperature of 25 and 90 °C in distilled water and simulated seawater. A normalized 137Cs mass loss (NLCs) estimated for corium samples after 168 days in distilled and seawater was 3.2–3.5 g/m2 at 25 °C and 113–114 g/m2 at 90 °C. For “lava” samples NLCs varied from 1.4 to 13.2 g/m2 at 90 °C for 56 days (in distilled and seawater) and from 0.1 to 0.4 g/m2 at 25 °C in seawater for 140 days. Chemical durability of Chernobyl “lava” in distilled and seawater evaluated using 137Cs specific activity in leachates is higher than one for corium. Further study is proposed in order to obtain more quantitative data.

Leaching of Plutonium from “Old” Samples of Single Phase Ceramics Based on Zr0.79Gd0.14Pu0.04O1.93 and La0.9Pu0.1PO4 Doped with 238Pu

MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4249-4253 ◽  
Author(s):  
Bella Yu Zubekhina ◽  
Boris E. Burakov
Keyword(s):  
Mass Loss ◽  
Radiation Damage ◽  
Single Phase ◽  
Xrd Analysis ◽  
Distilled Water ◽  
High Radiation ◽  
Cubic Zirconia ◽  
Leach Test

ABSTRACTSamples of 238Pu-doped single-phase ceramics based on cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, and monazite, La0.9Pu0.1PO4, have been studied by static leach test in distilled water. Before leach test accumulated doses were (in alpha-decays/m3 x 1026): from 1.6 to 1.7 – for cubic zirconia; and 1.0 – for monazite. Despite high radiation damage both phases remained crystalline according to XRD analysis. The results of static leach tests demonstrate the following Pu normalized mass loss (in g/m2, 90°C, 28 days): from 0.3 to 0.7 – for cubic zirconia; and 1.6 – for monazite. These data are discussed in comparison with results of previous leach tests carried out at lower accumulated doses.

scholarly journals Long-Term Aging of Chernobyl Fuel Debris: Corium and “Lava”

2021 ◽  
Vol 13 (3) ◽  
pp. 1073
Author(s):  
Bella Zubekhina ◽  
Boris Burakov ◽  
Ekaterina Silanteva ◽  
Yuri Petrov ◽  
Vasiliy Yapaskurt ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Mass Loss ◽  
Nuclear Power ◽  
Distilled Water ◽  
Chemical Alteration ◽  
Laboratory Conditions ◽  
Fukushima Daiichi ◽  
Important Basis

Samples of Chernobyl fuel debris, including massive corium and “lava” were collected inside the Chernobyl “Sarcophagus” or “Shelter” in 1990, transported to Leningrad (St. Petersburg) and stored under laboratory conditions for many years. In 2011 aged samples were visually re-examined and it was confirmed that most of them remained intact, although some evidence of self-destruction and chemical alteration were clearly observed. Selected samples of corium and “lava” were affected by static leaching at temperatures of 25, 90 and 150 °C in distilled water. A normalized Pu mass loss (NLPu) from corium samples after 140 days was noted to be 0.5 g/m2 at 25 °C and 1.1 g/m2 at 90 °C. For “lava” samples NLPu was 2.2–2.3 g/m2 at 90 °C for 140 days. The formation of secondary uranyl phases on the surface of corium and “lava” samples altered at 150 °C was confirmed. The results obtained are considered as an important basis for the simulation of fuel debris aging at Fukushima Daiichi nuclear power plant (NPP).

New route for synthesis of Synroc-like ceramic using non-selective sorbent LHT-9

MRS Advances ◽  
2018 ◽  
Vol 3 (20) ◽  
pp. 1111-1116 ◽  
Author(s):  
B.Yu. Zubekhina ◽  
B.E. Burakov ◽  
Yu.Yu. Petrov ◽  
S.N. Britvin ◽  
V.F. Mararitsa ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Chemical Durability ◽  
Bulk Liquid ◽  
Distilled Water ◽  
Selective Sorbent ◽  
Ceramic Synthesis ◽  
Multi Stage ◽  
High Level ◽  
Radionuclide Incorporation ◽  
Titanate Ceramic

ABSTRACT:Immobilization of bulk liquid high level radioactive waste (HLW) in Synroc ceramic is well-known reliable way for final isolation of dangerous long-lived radionuclides from biosphere. The alternative method of Synroc-like ceramic synthesis has been proposed. Radionuclide incorporation into crystalline titanate host-phases can be provided as a result of direct radionuclide sorption from liquid HLW using non-selective sorbent – layered hydrazinium titanate (LHT-9). Such an approach allows excluding expensive multi-stage procedure of precursor preparation. The precipitate obtained after sorption can be easily transformed into Synroc-like ceramic by cold pressing followed with sintering in air at 1000-1200°C. The highly radioactive samples of titanate ceramic loaded with real HLW have been synthesized and preliminary studied at KRI hot-cell facility. Chemical durability of this sample has been studied using static leach test in distilled water at 90°C and the leach rates for 154Eu, 241Am, 244Cm were (in g·m-2·day-1) from 2·10-4 to 5·10-3. Normalised 137Cs mass loss was 0.3 g·m-2 for 110 days at the same conditions.

The Geochemical and Mineralogical Assessment of Lime Stabilized Waste from the Petroleum Industry in Croatia

2004 ◽  
Vol 126 (2) ◽  
pp. 112-118 ◽  
Author(s):  
Goran Durn ◽  
Nediljka Gaurina- Med¯imurec ◽  
Heinz Fro¨schl ◽  
Ivan Meandzˇija ◽  
Boris Veronek ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Petroleum Industry ◽  
Underground Water ◽  
Distilled Water ◽  
Ongoing Research ◽  
Mineral Oils ◽  
Leach Test ◽  
Organophilic Clay ◽  
Siliceous Earth

The aim of this study was to geochemically and mineralogically assess materials from two already closed pits. Total testing and leachate testing (Equilibrium Leach Test and Sequential Leach Test) of topsoil, waste stabilized with lime and underlying rock was performed on composite samples. An analysis of underground water from underlying rock was also accomplished. Major pollutants in stabilized waste from investigated locations differ. High total values of some heavy metals in stabilized waste from one of the investigated locations can probably be attributed to high barite content (mercury, zinc and cadmium) and pipe dope (lead). Mercury, zinc and cadmium are enriched in the organic-sulfide fraction that might indicate they are tied up as sulfide impurities in barite. In distilled water lecheate of stabilized waste from this location higher concentrations of Pb, Hg and TOC were observed. In the stabilized waste from the second location high total values of total oils and mineral oils, PAH and BTEX were detected, while distilled water lecheate is enriched with Hg, total oils and mineral oils, AOX and TOC. This investigation shows that stabilization with lime is not always a suitable method for treatment of wastes from the petroleum industry, particularly those that are contaminated with both organic and inorganic contaminants. Proper characterization of the waste material to be processed is needed in order to select the most appropriate method of treatment. Our ongoing research study uses different pretreatment techniques and different absorbents (organophilic clay, calcined siliceous earth, etc.) to preferentially absorb organic contaminants that can be used before stabilization/solidification.

scholarly journals Cavitation erosion degradation of Belzona® coatings

2017 ◽  
Vol 17 (1) ◽  
pp. 22-33
Author(s):  
Ł. Bolewski ◽  
M. Szkodo ◽  
M. Kmieć
Keyword(s):  
Mass Loss ◽  
Steel Surface ◽  
Cavitation Erosion ◽  
Superior Performance ◽  
Distilled Water ◽  
Cavitation Resistance ◽  
Maritime Industry ◽  
Drilling Mud ◽  
P110 Steel ◽  
High Elasticity

Abstract In hydrocarbon and maritime industry there is a constant need of materials and coatings withstanding severe conditions. One of adverse phenomena present there is cavitation erosion. The paper presents evaluation of cavitation resistance of three different steel coatings. Belzona 2141 (ACR-Fluid Elastormer), 1321 (Ceramic S-Steal) and 5831 (ST-Barrier) were deployed on P110 steel and subjected to ultrasound cavitation in distilled water and drilling mud environment. According to mass loss measurements Belzona 2141 shows superior performance comparing to two other coatings and bare p110 steel surface. This is due to its high elasticity comparing to steel.

scholarly journals THE EFFECTS OF OSMOTIC LYSIS ON THE OXIDATIVE PHOSPHORYLATION AND COMPARTMENTATION OF RAT LIVER MITOCHONDRIA

1968 ◽  
Vol 36 (1) ◽  
pp. 15-31 ◽  
Author(s):  
Arnold I. Caplan ◽  
John W. Greenawalt
Keyword(s):  
Succinate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Rat Liver ◽  
Specific Activity ◽  
Liver Mitochondria ◽  
Progressive Increase ◽  
Outer Membrane Vesicles ◽  
Rat Liver Mitochondria ◽  
Distilled Water ◽  
Osmotic Lysis

Rat liver mitochondria isolated in 0.25 M sucrose were osmotically lysed with distilled water. The effect of osmotic lysis on mitochondrial compartmentation was monitored by following the changes in the specific Mg++-ATPase and the stimulation of this activity by DNP. Each resuspension in distilled water caused a progressive increase in the specific Mg++-ATPase and a decrease in DNP-stimulation. Lysed mitochondria yielded P:O ratios of slightly less than 1.0 when each of the "site-specific" substrates, NADH, D-ß-hydroxybutyrate, succinate, and ascorbate, were oxidized. These data indicate that only site 3 phosphorylation remained undiminished. The crude, lysed mitochondria were subfractionated by centrifugation on linear sucrose density gradients. Assays for protein, malate dehydrogenase, D-ß-hydroxybutyrate dehydrogenase, and succinate dehydrogenase indicated that the inner compartment could be clearly separated from the outer membrane vesicles. The results also suggested that the small vesicle fraction contained a small proportion of vesiculated inner membranes. Inner mitochondrial compartments, "contracted" by preincubation in the presence of ATP, sedimented to a markedly lower density on the gradients than did the unincubated preparations and about 50% of the ghosts showed a highly condensed morphology. In the contracted preparations, relatively low malate dehydrogenase and D-ß-hydroxybutyrate dehydrogenase activities were found in the fractions comprised of the inner compartments. The specific activity and distribution of succinate dehydrogenase were about the same as were found with the unincubated, lysed mitochondria.

scholarly journals Heavy Metals Leaching of Cementitious Matrices Containing Waste Ash from Brazzaville Landfills (Republic of Congo)

2019 ◽  
pp. 1-11
Author(s):  
K. M. Mbemba ◽  
M. B. Mabiala Loubilou ◽  
J. M. Ouamba
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Chemical Durability ◽  
Retention Rates ◽  
Household Waste ◽  
Distilled Water ◽  
Leaching Tests ◽  
Republic Of Congo

Inadequate management of ash generated by household waste burned in open air in Republic of Congo, generates pollution sites especially through heavy metal contamination (Pb, Ni, Cr, Cu, Zn). The aim of this study is to evaluate the chemical durability of cementitious matrices containing waste ashes and their ability to retain in their structure heavy metals contained in these ashes. To do this, we collected 40 kg of waste coming from 4 landfills (A, B, C, D) in Brazzaville city. Waste was then burned and turned into ash. 6 cementitious matrice formulations (P1, P2, P3, P4, P5, P6) based on Dolisie Portland cement were made by varying the cement/ash/lime rations. We carried out static leaching tests with raw ashes and cementitious matrices at pH = 7 and at 25°C in distilled water during 30 days. This study shows that cementitious matrices containing ash have good potentiality for retention of heavy metals (more than 75%). But, cementitious matrices containing ash and lime give better results with retention rates between 90-99%.

scholarly journals The Effects of Sand Particles on the Synergy of Cavitation Erosion-Corrosion of MIG Welding Stainless Steel Coating in Saline Water

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Haodan Pan ◽  
Jun Tao ◽  
Meng E ◽  
Hongxiang Hu ◽  
Zhengbin Wang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Mass Loss ◽  
Cavitation Erosion ◽  
Saline Water ◽  
Mass Loss Rate ◽  
Silica Sand ◽  
Distilled Water ◽  
Mig Welding ◽  
Corrosive Solution ◽  
Sand Particles

Cavitation erosion (CE) is a common problem troubling many flow-handling equipment such as valves, orifice plate pipes, and propellers. The coating technique is a widely used strategy to resist CE. It is important to understand the CE-corrosion behavior of the coatings in the corrosive solution, especially in the sand-containing saline water. A newly designed MIG welding precipitated hardened martensitic stainless steel (PHMSS) coating was performed, and its silt-CE was investigated in a suspension composed of 3.5 wt.% sodium chloride and 3% silica sand using an ultrasonic vibrator processor. The microstructure of the coating was characterized by optical microscopy and scanning electron microscopy. The effects of the sand particles on the CE-corrosion were analyzed using mass loss measurement, potentiodynamic polarization curve, and surface morphology observation. The results showed that the PHMSS coating was mainly composed of the lath martensitic phase alone. Its mass loss rate was in ascending order in the solution of distilled water alone, sand-containing distilled water, saline water alone, and sand-containing saline water. Sand particles played more roles in the CE in the distilled water than in the saline water. The synergy of CE and corrosion was much less in the sand-free saline than in the sand-containing saline. The maximum component was the erosion enhancement due to the corrosion in the saline without sand particles but was the pure erosion component in the saline with sand particles. The mechanism of the sand particles’ effect on the CE was also discussed.

scholarly journals Time-depending solubility of different fixed prosthetic permanent luting cements

2017 ◽  
Vol 63 (01) ◽  
pp. 35-39
Author(s):  
Nikola Gigovski ◽  
Vesna Korunoska Stevkovska ◽  
Aneta Mijoska ◽  
Sanja Pancevska ◽  
Emilija Valjakova Bajraktarova ◽  
...  
Keyword(s):  
Mass Loss ◽  
Prolonged Exposure ◽  
Single Case ◽  
Distilled Water ◽  
Glass Ionomer ◽  
Dental Cement ◽  
Luting Cements ◽  
Oral Fluids ◽  
Before And After

The solubility of dental cements is important property due to their prolonged exposure to oral fluids. Тhe recommended standard is 0.2% mass loss for 24 hours. The aim of the study is to measure and compare the values of the solubility in different types of permanent cements as a function of time of exposure to the solvent. Four types of cements were selected: zinc phosphate (ZP), glass-ionomer (GI), resin-modified glass-ionomer (RG) and polycarboxylate (PC) cement. Totally 120 samples, equally divided in 4 series, were fabricated according to the experimental method recommended for in vitro laboratory measuring of the mass loss of the cement due to solubility. Distilled water was used as a solvent. The measuring of every sample weight was performed before and after immersing in solvent for 1, 7, 14 and 21 days and mass loss was calculated as a percent of initial weight of the sample. According to the results, the mass loss of selected cements after immersion in distilled water for the initial 24hours period was 0.28% for ZP cement, 0.32% for RG, 0.51% for PC and 0.57% for GI cement. After this period, the mass loss decreased and was minimal at the end of the third week. The precise evaluation of this basic characteristic is necessary for predicting clinical behavior of the permanent cement and the exact cement selection in every single case. Keywords: permanent cementation, dental cement, solubility, dissolution

A high-resolution membrane probe

1990 ◽  
Vol 48 (3) ◽  
pp. 36-37
Author(s):  
James F. Hainfeld ◽  
James J. Lipka ◽  
F. Elsie Quaite
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Mass Loss ◽  
Specific Activity ◽  
Membrane Dynamics ◽  
Keggin Structure ◽  
Head Group ◽  
Membrane Probe ◽  
Varying Length

Labeling the lipids of membranes for E.M. is frequently done by using radioactive phospholipids. Membrane dynamics can then be followed by autoradiography. Unfortunately, it takes approximately 6 months to expose the emulsion due to the low specific activity of the labels. Also, the resolution is limited to about 0.2 μm by this technique.An alternative is to develop a phospholipid-like molecule that is electron dense and could be visualized directly. Several such molecules have been synthesized and one is shown in Fig. 1. They have a phosphotungstate “head” group that has a 4 (-) charge and is hydrophilic and an aliphatic “tail” of varying length that is hydrophobic. The tungstate cluster contains 11 tungsten atoms in the “Keggin” structure with a 1.0 nm diameter and has previously been studied in the electron microscope. It was shown to be almost completely resistant to beam induced mass loss.

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