Long-term behavior of a portland cement-electroplating sludge waste form in presence of copper nitrate

AbstractOne of the unique and scientifically most difficult aspects of nuclear waste isolation is the extrapolation ofshot-term laboratory data (hours to years) to the long time periods (103-105 years) required by regulatory agencies for performance assessment. The direct verification of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural analogues of both the repository environment (e.g. radionuclide migration at Oklo) and nuclear waste form behavior (e.g. alteration of basaltic glasses and radiation damage in minerals) have been used to demonstrate the long-term behavior of large scale geologic systems and, on a smaller scale, waste form durability. This paper reviews the use of natural analogues to predict the long-term behavior of nuclear waste form glasses. Particular emphasis is placed on the inherent limitations of any conclusions that are based on “proof” by analogy. An example -- corrosion of borosilicate glass -- is discussed in detail with specific attention to the proper and successful use of natural analogues (basaltic glass) in understanding the long-term corrosion behavior of borosilicate glass.

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

ISRN Chemical Engineering ◽

10.5402/2012/329676 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 10

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.

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Mobilization/Retention of Radionuclides during Corrosion of High Burnup Spent Fuel and Backfill Materials in Salt Brines

MRS Proceedings ◽

10.1557/proc-757-ii8.2 ◽

2002 ◽

Vol 757 ◽

Cited By ~ 1

Author(s):

Andreas Loida ◽

Bernhard Kienzler ◽

Horst Geckeis

Keyword(s):

Near Field ◽

Waste Form ◽

Spent Fuel ◽

The Matrix ◽

Backfill Materials ◽

Salt Brine ◽

Solid Phases ◽

Long Term Behavior ◽

The Impact

ABSTRACTWith respect to the assessment of the long-term behavior of the waste form spent fuel it is of high importance to study the fuel alteration in contact with groundwater and near field materials. The aim of this work is to evaluate the impact of candidate backfill materials hydroxylapatite and magnetite on the overall corrosion behavior of this waste form in salt brine; both materials are used in corrosion tests together with spent fuel. The instant releases and the matrix dissolution rates appear to be similar in presence and in absence of any backfill material under study. However, Am,Np,Pu,U and Sr are retained at different ratios on the hydroxylapatite, on the magnetite and on the fuel sample, indicating possibly the formation of different radionuclide containing new solid phases.

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Plutonium-Doped Monazite and Other Orthophosphates—Thermodynamics and Experimental Data on Long-Term Behavior

Sustainability ◽

10.3390/su13031203 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1203

Author(s):

Polina Mikhailova ◽

Boris Burakov ◽

Nikolai Eremin ◽

Alexei Averin ◽

Andrey Shiryaev

Keyword(s):

Current Data ◽

Waste Form ◽

Atmospheric Moisture ◽

Gibbs Energies ◽

Structural Types ◽

Crystalline Crust ◽

Acidic Compounds ◽

Short Time ◽

Long Term Behavior

The paper consists of two main parts: a microscopic and spectroscopic investigation of the single crystal of 17-year-old 238Pu-doped Eu-monazite, and a theoretical calculation of the properties of several structural types of orthophosphates. It is shown that actinide-doped monazite is prone to the formation of mechanically weak, poorly crystalline crust, presumably consisting of rhabdophane. Its formation is likely promoted by the formation of peroxides and, potentially, acidic compounds, due to the radiolysis of atmospheric moisture. The calculations of mixing the enthalpies and Gibbs energies of binary solid solutions of Pu and rare earth element (REE) phosphates that were performed for the principal structural types—monazite, xenotime, rhabdophane—show that, in the case of light REEs, the plutonium admixture is preferentially redistributed into the rhabdophane. This process strongly affects the behavior of actinides, leached from a monazite-based waste form. The applications of these results for the development of actinide waste forms are discussed. The current data on the behavior of real actinide-doped monazite suggest that this type of ceramic waste form is not very resistant, even in relatively short time periods.

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Long-Term Behavior of Bitumen Waste Form

MRS Proceedings ◽

10.1557/proc-608-571 ◽

1999 ◽

Vol 608 ◽

Cited By ~ 6

Author(s):

I.A. Sobolev ◽

A.S. Barinov ◽

M.I. Ojovan ◽

N.V. Ojovan ◽

I.V. Startceva ◽

...

Keyword(s):

Waste Form ◽

Long Term Behavior

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Study of Natural Minerals of U-Ryrochlore-Type Structure as Analogues of Plutonium Ceramic Waste-form

MRS Proceedings ◽

10.1557/proc-713-jj2.2 ◽

2002 ◽

Vol 713 ◽

Cited By ~ 1

Author(s):

Roman V. Bogdanov ◽

Yuri F. Batrakov ◽

Elena V. Puchkova ◽

Andrey S. Sergeev ◽

Boris E. Burakov

Keyword(s):

Chemical Shifts ◽

Pyrochlore Structure ◽

Type Structure ◽

Waste Form ◽

X Ray ◽

Ceramic Waste ◽

Natural Minerals ◽

The Us ◽

Pyrochlore Type

ABSTRACTAt present, crystalline ceramic based on titanate pyrochlore, (Ca,Gd,Hf,Pu,U)2Ti2O7, is considered as the US candidate waste form for the immobilization of weapons grade plutonium. Naturally occuring U-bearing minerals with pyrochlore-type structure: hatchettolite, betafite, and ellsworthite, were studied in orders to understand long-term radiation damage effects in Pu ceramic waste forms. Chemical shifts (δ) of U(Lδ1)– and U(Lβ1) – X-ray emission lines were measured by X-ray spectrometry. Calculations were performed on the basis of a two-dimensional δLá1- and δLδ1- correlation diagram. It was shown that 100% of uranium in hatchettolite and, probably, 95-100% of uranium in betafite are in the form of (UO2)2+. formal calculation shows that in ellsworthite only 20% of uranium is in the form of U4+ and 80% of the rest is in the forms of U5+ and U6+. The conversion of the initial U4+ ion originally occurring in the pyrochlore structure of natural minerals to (UO2)2+ due to metamict decay causes a significant increase in uranium mobility.

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Effects of acute seizures on cell proliferation, synaptic plasticity and long-term behavior in adult zebrafish

Brain Research ◽

10.1016/j.brainres.2021.147334 ◽

2021 ◽

Vol 1756 ◽

pp. 147334

Author(s):

Charles Budaszewski Pinto ◽

Natividade de Sá Couto-Pereira ◽

Felipe Kawa Odorcyk ◽

Kamila Cagliari Zenki ◽

Carla Dalmaz ◽

...

Keyword(s):

Cell Proliferation ◽

Synaptic Plasticity ◽

Adult Zebrafish ◽

Acute Seizures ◽

Long Term Behavior

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Using Generalized Cell Mapping to Approximate Invariant Measures on Compact Manifolds

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127497001667 ◽

1997 ◽

Vol 07 (11) ◽

pp. 2487-2499 ◽

Cited By ~ 10

Author(s):

Rabbijah Guder ◽

Edwin Kreuzer

Keyword(s):

Dynamical Systems ◽

Invariant Measures ◽

Nonlinear Dynamical Systems ◽

Powerful Method ◽

Cell Mapping ◽

Generalized Cell Mapping ◽

Nonlinear Dynamical ◽

Long Term Behavior ◽

Mapping Theory

In order to predict the long term behavior of nonlinear dynamical systems the generalized cell mapping is an efficient and powerful method for numerical analysis. For this reason it is of interest to know under what circumstances dynamical quantities of the generalized cell mapping (like persistent groups, stationary densities, …) reflect the dynamics of the system (attractors, invariant measures, …). In this article we develop such connections between the generalized cell mapping theory and the theory of nonlinear dynamical systems. We prove that the generalized cell mapping is a discretization of the Frobenius–Perron operator. By applying the results obtained for the Frobenius–Perron operator to the generalized cell mapping we outline for some classes of transformations that the stationary densities of the generalized cell mapping converges to an invariant measure of the system. Furthermore, we discuss what kind of measures and attractors can be approximated by this method.

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