CFG Services

Orléans, France

CFG Services

Orléans, France
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Necib S.,Andra Inc | Bataillon C.,Chatenay Malabry | Crusset D.,CEA Saclay Nuclear Research Center | Daumas S.,CFG Services | And 2 more authors.
EUROCORR 2013 - European Corrosion Congress | Year: 2013

Carbon steel has been chosen to be the material for the metallic components of the high level waste (hLW) French repository. There are two main metallic components involved. One is called "liner" and its main function is to ensure mechanical resistance. The second one called "overpack", is to prevent water from reaching the vitrified HLW during the thermal phase. One of the key issues was to measure the instantaneous in situ corrosion rate of carbon steel in clay environments at 80°C under anoxic conditions. Electrochemical impedance spectroscopy (eIS) has been used to measure instantaneous corrosion rates of different types of carbon steel materials under consideration to be used in the future HLW repository concept. The measurements have been performed by connecting the carbon steel materials to a potentiostat. Potential measurements have been carried out before and after measuring the corrosion rate in order to check the stationary state, as well as, the impact of the EIS measurements on it. Water sampling has been performed for chemical and microbial analyses, to understand the corrosion processes. After four years of experiment, carbon steel materials have shown a decrease of the corrosion rate over time in clay environments. This was explained by the passivating effect of the corrosion products formed on the surface of the materials under anoxic conditions. Passivation is promoted by the confinement of the environment in contact with the carbon steel materials. Results from microbial analyses show the presence of sulphate reducing bacteria (SRB) and thiosulphate reducing bacteria (TRB). Their metabolism was confirmed by a decrease of the sulphate concentration present in clay pore water. Their impact on general corrosion was negligible. However, investigation on localised corrosion will have to be considered further after dismantling.

Blount G.,Savannah River National Laboratory | Gorensek M.,Savannah River National Laboratory | Hamm L.,Savannah River National Laboratory | O'Neil K.,Partnering in Innovation Inc. | And 2 more authors.
Energy Procedia | Year: 2014

Partnering in Innovation, Inc. (Pi-Innovation) introduces an aqueous post-combustion carbon dioxide (CO2) capture system (Pi- CO2) that offers high market value by directly addressing the primary constraints limiting beneficial re-use markets (lowering parasitic energy costs, reducing delivered cost of capture, eliminating the need for special solvents, etc.). A highly experienced team has completed initial design, modeling, manufacturing verification, and financial analysis for commercial market entry. Coupled thermodynamic and thermal-hydraulic mass transfer modeling results fully support proof of concept. Pi-CO2 has the potential to lower total cost and risk to levels sufficient to stimulate global demand for CO2 from local industrial sources. © 2014 The Authors. Published by Elsevier Ltd.

Kervevan C.,Bureau de Recherches Géologiques et Minières | Beddelem M.-H.,CFG Services | O'Neil K.,Partnering in Innovation Inc.
Energy Procedia | Year: 2014

The CO2-DISSOLVED project evaluates the feasibility of coupling capture and storage in saline aquifer of dissolved CO2, and geothermal heat recovery. The proposed system basically relies on the integration of a patented water-based in-well CO2 capture facility (Pi-CO2) in a classical low-enthalpy geothermal doublet. The results of this preliminary engineering design study demonstrated that (1) the use of composite materials for the wells casings would be compatible with the injection of the corrosive CO2-rich brine; (2) the housing of the Pi-CO2 system in a separate large diameter well associated with a dedicated CO2 injection line integrated in the doublet injection well is the best option for efficient CO2 capture and dissolution in brine. © 2014 The Authors. Published by Elsevier Ltd.

Randi A.,CNRS Georesources lab | Sterpenich J.,CNRS Georesources lab | Morlot C.,CNRS Georesources lab | Pironon J.,CNRS Georesources lab | And 3 more authors.
Energy Procedia | Year: 2014

The CO2-DISSOLVED project aims at assessing the feasibility of the coupling between dissolved CO2 storage in aquifer and geothermal heat recovery. The MIRAGES-2 experimental setup has been designed to study, at the centimeter scale and under relevant conditions of pressure and temperature, the chemical interactions in the near-injection well area between the reservoir rock, the cement phases, and the corrosive CO2-rich solution. This original experimental setup allows performing flow-through experiments with continuous in-situ data acquisition of pressure, temperature, flow rate, pH, and dissolved CO2 concentration. The datasets acquired will be further interpreted with the help of geochemical models, in order to better understand the effects of the key physical-chemical processes involved. © 2014 The Authors. Published by Elsevier Ltd.

Brenot A.,Bureau de Recherches Géologiques et Minières | Negrel P.,Bureau de Recherches Géologiques et Minières | Petelet-Giraud E.,Bureau de Recherches Géologiques et Minières | Millot R.,Bureau de Recherches Géologiques et Minières | Malcuit E.,CFG Services
Applied Geochemistry | Year: 2015

The multi-layered Eocene aquifer is a regional scale sedimentary aquifer system occupying ~120,000km2 within the Adour-Garonne district (France). Local authorities have recently identified the aquifer as being at risk from extensive irrigation abstractions, threatening the sustainability of this key resource. Because large water abstractions for human activities can significantly influence the natural functioning of such aquifer systems, e.g., with leakage between aquifer layers, which can lead to water quality degradation, the characterization of such large systems constitutes a key point to protect and prevent further deterioration of aquatic ecosystems. This study provides further insight on this large aquifer through a geochemical approach, which addresses the limited number of groundwater wells where sampling is possible. For that purpose, a geochemical analysis combining two isotope systems (δ34SSO4, δ18OSO4 and 87Sr/86Sr) has been applied. The Eocene sedimentary aquifer system (detrital to carbonate deposits) is made up of four aquifer layers, Eocene Infra-Molassic sand, Early Eocene, Middle Eocene and Late Eocene, and has a mineralized area north of the Aquitaine Basin, where groundwater shows strong mineralization and anomalous levels of critical substances (SO4, F, etc.), increasing the difficulty of resource exploitation. The extreme heterogeneity of the geochemical composition of the groundwater between the aquifers and within a single aquifer is discussed in terms of the lithological control induced by the lateral variation of facies and interconnections between aquifer layers. Geochemical tools, especially the δ34S and δ18O from dissolved sulfates and the 87Sr/86Sr ratio, suggest that evaporite dissolution (both sulfate and halite) is the main process controlling the high salinity levels observed in the groundwater, explaining the spatial variations observed at the aquifer system scale. Isotopic tools also provide new information regarding the interconnections between aquifer layers, supporting the hypothesis that the Eocene aquifer system integrates groundwater from the Oligocene-Miocene aquifer through leakage effects. These new insights will likely help decision-makers adjust their choices when managing quality problems, in particular in the "mineralized area of the Entre-Deux-Mers," where targeted groundwater wells used for drinking water display anomalous levels of critical substances. © 2014 Elsevier Ltd.

Malcuit E.,CFG Services | Atteia O.,ENSEGID IPB | Larroque F.,ENSEGID IPB | Franceschi M.,ENSEGID IPB | Pryet A.,ENSEGID IPB
Journal of Contaminant Hydrology | Year: 2014

Fluoride (F-) commonly threatens groundwater quality. This is the case around the city of Bordeaux (France), where numerous wells tapping the thick and complex Eocene aquifer are contaminated by fluoride, which presents an issue for drinking water supply. The joint analysis of the spatial distribution of fluoride with other species like sulfate suggests that concentrations are mainly related to the occurrence of low-permeability layers containing evaporites or fluorite deposits. In order to identify the origin of the observed concentrations, a radial flow and transport model is implemented at the borehole scale. The hydraulic conductivity of the low-permeability layers and the vertical dispersivity of the aquifer were optimized to match the observed values of sulfate and fluoride concentrations. Interestingly, each of these parameters influences differently the simulated concentrations. This model has been successfully implemented to a neighboring well with the same parameter values, which tests the approach. The major conclusions drawn are: (i) the contamination in fluoride originates from the low-permeability layers, (ii) every low-permeability layer intercepted by the well releases fluoride (iii) Contamination not only originates from pore water of low-permeability layers, but may persist with long-term pumping due to mineral dissolution. As a consequence, fluoride contamination is likely to persist for a long time and the only solution to reduce fluoride concentration in abstracted water is to seal well screens facing low-permeability layers. © 2014 Elsevier B.V.

Lopez S.,Bureau de Recherches Géologiques et Minières | Hamm V.,Bureau de Recherches Géologiques et Minières | Le Brun M.,Bureau de Recherches Géologiques et Minières | Schaper L.,Bureau de Recherches Géologiques et Minières | And 3 more authors.
Geothermics | Year: 2010

Geothermal energy has been supplying heat to district networks in the Paris Basin for more than 40 years. The most serious difficulties have been corrosion and scaling related problems that occurred in many geothermal loops in the mid-1980s. The main target of all exploration and exploitation projects has been the Dogger aquifer. Most of the operating facilities use the "doublet" technology which consists of a closed loop with one production well and one injection well. Injection of the cooled brines leads to the progressive exhaustion of the resource at the local doublet scale. Consequently, most of the research effort has been focused on quantifying the temporal evolution of the cooling, and to forecast the lifetimes of doublets and the occurrence of the "thermal breakthrough" At the turn of the 21st century, there was a revival of geothermal energy development in France and new projects are presently being considered. The 40 years of experience in geothermal exploitation of the Paris basin constitutes a firm basis upon which to devise a sustainable regional management approach for the geothermal resource. Several governmental policies seek to promote further geothermal development of the Dogger aquifer with structures in place to facilitate technical studies. © 2010 Elsevier Ltd.

Schlegel M.L.,CEA Saclay Nuclear Research Center | Schlegel M.L.,University of Évry Val d'Essonne | Necib S.,Andra Inc | Daumas S.,CFG Services | And 4 more authors.
Corrosion Science | Year: 2016

The corrosion interface of low-alloy carbon steel (C-steel) coupons (P235, ferrite-pearlitic with a columnar microstructure) reacted in clay porewater seeping in a test chamber in situ in the Callovo-Oxfordian formation of the Meuse-Haute Marne Underground laboratory (France) was probed by microscopic and microspectrocopic techniques. Two series of samples were investigated, with extensive and limited corrosion, respectively. For extensively corroded coupons, several layers of inner corrosion products were observed. The innermost layer was made of Cl-rich Fe (hydr)oxide, later evolving to form a massive β-Fe2(OH)3Cl unit close to C-steel, and sometimes crossed by magnetite ribbons sticking to cementite lamellas, or by patches of green rust. The second inner layer was made of veinlets of Fe hydrated silicate with a sponge-like morphology, a molecular-scale structure reminiscent of clay minerals, and containing nodules of siderite and chukanovite. These (hydroxy)carbonate solids sometimes merged to form a massive layer close to the trace of the original surface. The layers external to this original surface were discontinuous and made of successively Ca-doped siderite (ankerite), Fe sulfide, S-rich Fe silicate, and finally pyrite nodules and ankerite. For the samples with limited damage, no β-Fe2(OH)3Cl layer was observed, siderite or chukanovite were in close contact with metal, sometimes with interfacial magnetite, and the veinlets of Fe hydrated silicate were less developed. Only external layers of Fe sulfide and ankerite were observed. This suggests that these slightly corroding samples were in fact confined. Evidence for microbial activity was obtained in the form of a Fe sulfide fringe mixed with ankerite. Microbial activity may have induced some local heterogeneity in corrosion processes, e.g. by changing local pH conditions at mm-scale. © 2016 Elsevier Ltd.

In the 1980s, the oil and gas industry discovered that pitting and crevice corrosion on carbon steel (GS) pipelines and well casings were caused by sessile bacteria such as sulfate-reducing bacteria (SRB) and thiosulfate-reducing bacteria (TRB).

Bouchot V.,Bureau de Recherches Géologiques et Minières | Gadalia A.,Bureau de Recherches Géologiques et Minières | Traineau H.,CFG Services | Caritg S.,Bureau de Recherches Géologiques et Minières
Transactions - Geothermal Resources Council | Year: 2014

The recent surface exploration data acquired in Martinique led to a revisit of the conceptual models of three geothermal systems in active volcanic arc context: Petite Anse in the Southwest of the island, Lamentin in the center, Montagne Pelée in the North. These three explored systems are compared with each other and with the developed Bouillante geothermal field in Guadeloupe (15 MWe). From parameters, such as reservoir temperature, duration of the geothermal system using fossils events, age and duration of magmatism, degree of equilibrium of geothermal fluid, we propose a continuum model of geothermal system including three successive stages: prograde, peak and retrograde. Copyright © (2014) by the Geothermal Resources Council All right reserved.

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