Effects of Microorganisms Growth on the Long-Term Stability of Cement and Bitumen

1992 ◽  
Vol 294 ◽  
Author(s):  
Marie F. Libert ◽  
R. Sellier ◽  
G. Jouquet ◽  
M. Trescinski ◽  
H. Spor
Keyword(s):  
Organic Acids ◽  
Nuclear Waste ◽  
Long Term Stability ◽  
Mineral Acids ◽  
Ph Conditions ◽  
Waste Repositories ◽  
Coating Matrix ◽  
Geological Formations ◽  
Growth Of Fungi

ABSTRACTCement is used as a coating matrix for nuclear waste or as an engineered barrier of waste repositories situated in geological formations.The effect of mineral acids excreted by bacteria (Thiobacillus) or organic acids produced by fungi, on the biodegradation of cement is discussed. Organic acids are quantitatively and qualitatively determined during growth of fungi over a two-year period. Even with high pH conditions, pH of the cement ≈ 11, growth of microorganisms occurs.Biodeterioration of cement is expressed in terms of bioleaching velocity of calcium and is observed by electron microscopy.

scholarly journals A multiple-code simulation study of the long-term EDZ evolution of geological nuclear waste repositories

2008 ◽  
Vol 57 (6) ◽  
pp. 1313-1324 ◽  
Author(s):  
Jonny Rutqvist ◽  
Ann Bäckström ◽  
Masakazu Chijimatsu ◽  
Xia-Ting Feng ◽  
Peng-Zhi Pan ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Simulation Study ◽  
Multiple Code ◽  
Waste Repositories

LONG-TERM THERMOHYDROLOGIC BEHAVIOR OF NUCLEAR-WASTE REPOSITORIES

1982 ◽  
pp. 101-115
Author(s):  
J.S.Y. Wang ◽  
C.F. Tsang ◽  
N.G.W. Cook ◽  
P.A. Witherspoon
Keyword(s):  
Nuclear Waste ◽  
Waste Repositories

Long-term stability of hydrogen and organic acids production in an anaerobic fluidized-bed reactor using heat treated anaerobic sludge inoculum

2009 ◽  
Vol 34 (9) ◽  
pp. 3679-3688 ◽  
Author(s):  
Gessia Momoe Shida ◽  
Aruana Rocha Barros ◽  
Cristiane Marques dos Reis ◽  
Eduardo Lucena Cavalcante de Amorim ◽  
Márcia Helena Rissato Zamariolli Damianovic ◽  
...  
Keyword(s):  
Organic Acids ◽  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Anaerobic Sludge ◽  
Term Stability ◽  
Long Term Stability ◽  
Heat Treated ◽  
Anaerobic Fluidized Bed Reactor

Glass/Water Reaction with and without Bentonite Present - Experiment and Model

1985 ◽  
Vol 50 ◽  
Author(s):  
B. Grambow ◽  
H. P. Hermansson ◽  
I. K. Björner ◽  
L. Werme
Keyword(s):  
Nuclear Waste ◽  
Water Permeability ◽  
Borosilicate Glass ◽  
Waste Form ◽  
Nuclear Waste Repository ◽  
Aqueous Environment ◽  
Long Term Stability ◽  
Chemical Effects ◽  
Waste Repository

In nuclear waste repository design bentonite has been included as part of the backfill for its sorbtive capacity and low water permeability. Nevertheless, it cannot keep the waste form dry once intrusion of groundwater has occured [1]. Leach experiments [2], [3] with the radioactive nuclear waste form borosilicate glass JSS-A have been performed with and without bentonite present to provide a database which allows the long term stability of the glass in aqueous environment to be forecasted and the chemical effects of bentonite to be studied.

A natural cement analogue study to understand the long-term behaviour of cements in nuclear waste repositories: Maqarin (Jordan)

2016 ◽  
Vol 71 ◽  
pp. 20-34 ◽  
Author(s):  
Lukas H.J. Martin ◽  
Andreas Leemann ◽  
Antoni E. Milodowski ◽  
Urs K. Mäder ◽  
Beat Münch ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Analogue Study ◽  
Waste Repositories

scholarly journals Bentonite clay barriers in nuclear waste repositories

2020 ◽  
Vol 205 ◽  
pp. 01003
Author(s):  
Lyesse Laloui ◽  
Alessio Ferrari ◽  
Jose A. Bosch
Keyword(s):  
Nuclear Waste ◽  
Constitutive Models ◽  
Bentonite Clay ◽  
In Situ Experiment ◽  
Future Prediction ◽  
Bentonite Clays ◽  
High Level ◽  
Waste Repositories ◽  
Clay Barriers

Deep disposal of high-level radioactive waste is the preferred solution worldwide for the long-term disposal of nuclear waste. This concept involves a series of geological and engineered barriers that provide isolation of the waste from the biosphere. Most designs involve bentonite clays as seals in different forms. During the operation of the repository, the bentonite will be subjected to a series of complex thermo-hydro-mechanical phenomena that will interact with each other. Predicting the long-term safety of geological repositories thus involve a rigorous analysis of these multi-physical processes. This paper presents a review of recent numerical approaches and analyses that have aimed to improve the understanding of processes that will take place in clay barriers over the lifetime of nuclear waste repositories. The understanding of bentonite behavior from laboratory experiments under relevant conditions is analyzed. Constitutive models that attempt to predict such behavior are presented, focusing on the stress-strain model ACMEG-TS. These models are implemented in the finite element code Lagamine which allows for the study of real scale tests. Two application cases are presented: the performance of a clay barrier according to the Swiss design, and a model of the FEEBX in situ experiment, which was modelled after a real repository under natural conditions. Overall, the relevant processes are well captured quantitatively by the models, allowing for the establishment of sound basis for future prediction and long-term design of the final underground repositories.

Predicting Pu Concentrations in Solutions Contacting Geologic Materials

1981 ◽  
Vol 6 ◽  
Author(s):  
Richard G. Strickert ◽  
Dhanpat Rai
Keyword(s):  
Nuclear Waste ◽  
Safety Assessment ◽  
High Level Waste ◽  
Stable Phase ◽  
Borosilicate Glasses ◽  
Geologic Materials ◽  
Solid Phases ◽  
High Level ◽  
Waste Repositories

ABSTRACTKnowledge of Pu solid phases present in nuclear wastes is important for predicting the geochemical behavior of Pu. Thermodynamic data and experimental measurements using discrete Pu compounds, Pu-doped borosilicate glasses (simulating a high-level waste form), and Pu contaminated sediments suggest that PuO2(c) is very stable and is expected to be present in the repository. The solubility of the stable phase, such as PuO2(c), can be used to predict the maximum Pu concentration in solutions for long-term safety assessment of nuclear waste repositories.

Application of electrochemical methods in the development of models for fuel dissolution and container corrosion under nuclear waste disposal conditions

1997 ◽  
Vol 75 (11) ◽  
pp. 1566-1584 ◽  
Author(s):  
D.W. Shoesmith ◽  
W.H. Hocking ◽  
B.M. Ikeda ◽  
F. King ◽  
J.J. Noël ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Anodic Dissolution ◽  
Nuclear Waste ◽  
Chloride Solutions ◽  
Long Term Stability ◽  
Waste Container ◽  
Transport Barriers ◽  
Long Term Performance ◽  
Term Performance

The permanent disposal of nuclear fuel wastes requires the development of models that can assess the performance of a disposal vault over long periods of time. Models to assess the long-term stability of the nuclear fuel (UO2) and the corrosion performance of the waste container (either copper or titanium) have been based on electrochemical principles. Here we review the chemical/electrochemical performance of fuel and the two candidate container materials, and describe some of the electrochemical studies undertaken either to develop the mechanistic understanding upon which these models are based or to measure the values of parameters required to evaluate long-term performance. These include the following: the anodic dissolution of UO2; the reduction of O2 on various specimens of UO2; the crevice corrosion of various titanium alloys; the impedance characteristics of passive films on Ti alloys; the anodic dissolution of copper in chloride solutions; the reduction of O2 on copper; the effect of various transport barriers on the corrosion of copper; and the prediction of the corrosion potential of copper in aerated chloride solutions. Keywords: uranium dioxide, copper, titanium, nuclear waste, oxygen.

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