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Grant
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: NFRP-06-2014 | Award Amount: 9.66M | Year: 2015

The Modern2020 project aims at providing the means for developing and implementing an effective and efficient repository operational monitoring programme, taking into account the requirements of specific national programmes. The work allows advanced national radioactive waste disposal programmes to design monitoring systems suitable for deployment when repositories start operating in the next decade and supports less developed programmes and other stakeholders by illustrating how the national context can be taken into account in designing dedicated monitoring programmes tailored to their national needs. The work is established to understand what should be monitored within the frame of the wider safety cases and to provide methodology on how monitoring information can be used to support decision making and to plan for responding to monitoring results. Research and development work aims to improve and develop innovative repository monitoring techniques (wireless data transmission, alternative power supply sources, new sensors, geophysical methods) from the proof of feasibility stage to the technology development and demonstration phase. Innovative technical solutions facilitate the integration and flexibility of required monitoring components to ease the final implementation and adaptation of the monitoring system. Full-scale in-situ demonstrations of innovative monitoring techniques will further enhance the knowledge on the operational implementation of specific disposal monitoring and will demonstrate the performance of the state-of-the-art, the innovative techniques and their comparison with conventional ones. Finally, Modern2020 has the ambition to effectively engage local citizen stakeholders in the R&D monitoring activity by involving them at an early stage in a repository development programme in order to integrate their concerns and expectations into monitoring programmes.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: Fission-2008-1.1.2 | Award Amount: 5.11M | Year: 2009

The MoDeRn project aims at providing a reference framework for the development and possible implementation of monitoring activities and associated stakeholder engagement during relevant phases of the radioactive waste disposal process, i.e. during site characterisation, construction, operation and staged closure, as well as a post-closure institutional control phase. Monitoring provides operators and other stakeholders with in-situ data on repository evolutions, to contribute to operational safety, to help manage construction, operation and/or closure activities, and may allow for a comparison with prior safety assessments. It thus provides information to inform necessary decisions. If, in addition, monitoring activities respond to stakeholder needs and provide them with understandable results, they will contribute to transparency and possibly to stakeholder confidence in the disposal process. The project is structured into six work packages (WPs). The first four WPs are dedicated to (i) analyze key objectives and propose viable strategies, based on both technical and stakeholder considerations; to (ii) establish the state of the art and provide technical developments to match specific repository requirements; to (iii) conduct in-situ monitoring demonstration experiments using innovative techniques; and to (iv) conduct a case study of monitoring and its integration into staged disposal, including specific scenarii analysis aimed at providing guidance on how to handle and communicate monitoring results, in particular when these provide unexpected information. In order to provide a shared international view on how monitoring can be developed within a given national context, WP5 regroups key dissemination activities and WP6 will provide a reference framework integrating project results and describing feasible monitoring activities, suggesting relevant stakeholder engagement activities, and illustrating possible uses of monitoring results for decision-making.


Schlegel R.,Dynardo GmbH | Will J.,Dynardo GmbH | Jobmann M.,DBE Technology GmbH
2nd EAGE Workshop on Geomechanics and Energy: The Ground as Energy Source and Storage | Year: 2015

In the framework of a heater experiment at the Meuse/Haute-Marne rock laboratory, DBE TECHNOLOGY and Dynardo performed an analysis of the rock behaviour in response to heating. New approaches describing rock permeability as a function of streb and plastic strain were used, and statistical methods for parameter identification were applied. The methods comprise automatic sensitivity analysis and optimization algorithms that allow a parameter fitting and an analysis of the importance of individual parameters for the general system development. The identification proceb resulted in a parameter set that allows a good description of the rock behaviour while being heated. © Copyright 2015 EAGE.


Jobmann M.,DBE Technology GmbH | Billaux D.,ITASCA Consultants S.A.S
International Journal of Rock Mechanics and Mining Sciences | Year: 2010

An excavation damaged zone (EDZ) around emplacement boreholes for radioactive waste represents a potential pathway for radionuclides, due to its increased porosity and crack permeability. As clay is one of the potential host rocks for radioactive waste disposal, a methodical approach was developed for permeability calculation of damaged opalinus clay. The approach was based on a permeability-porosity relationship and on the theory of fractals, which allows the description of rock mass properties by fractal dimensions. It was calibrated against laboratory test data and provides the possibility to calculate the permeability from the pore size parameters "effective porosity" and "pore radius" as well as from the fractal dimension. An application of this relationship was given in terms of calculating the EDZ permeability around a vertical 50. m deep emplacement borehole in opalinus clay at a German generic repository site. The Particle Flow Code (PFC) was applied to simulate the fissure development in the EDZ. The results of the simulation provide the necessary pore size parameters. Considering the thermo-mechanical impact of adjacent, already filled, boreholes in an emplacement field for heat-generating radioactive waste, the crack occurrence and evolution over time in the EDZ of a newly drilled borehole was calculated on a 2D horizontal plane. A 3D calculation as well as a verification against in-situ data is still pending. © 2010 Elsevier Ltd.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: Fission-2012-1.1.1 | Award Amount: 15.74M | Year: 2012

DOPAS aims to improve the adequacy and consistency regarding industrial feasibility of plugs and seals, the measurement of their characteristics, the control of their behavior over time in repository conditions and also their hydraulic performance acceptable with respect to the safety objectives. This DOPAS project addresses the design basis, reference designs and strategies to demonstrate the compliance of the reference designs to the design basis, for plugs and seals in geological disposal facilities. The project focuses on shaft seals for salt rock (German repository concept), tunnel plugs for clay rock (French and Swiss repository concepts), and tunnel plugs for crystalline rock (Czech, Finnish and Swedish repository concepts). Five different demonstration experiments are part of the project and will take place in Sweden, France, Finland, Czech Republic and Germany. They are in different state-of-development. The Swedish demonstrator will be constructed prior to start of the DOPAS project and will basically provide experience on demonstration of compliance of reference design to the design basis. German demonstrator will be installed after the DOPAS project and will focus on demonstration of suitability by performance assessment. The French, Finnish, Swedish,German and the Czech experiments will address developments in all phases of design basis, reference designs and strategies to demonstrate compliance of reference designs to design basis. The studied concepts will be developed in the DOPASs five thematic scientific/technological work packages, which each integrate the results of the individual experiments. The DOPAS project is derived from the IGD-TPs Strategic Research Agenda that points out the topic of plug and seals as a first priority issue for joint European RTD projects.


Jobmann M.,DBE Technology GmbH | Wilsnack Th.,IBeWa Ingenieurpartnerschaft | Voigt H.-D.,TU Bergakademie Freiberg
International Journal of Rock Mechanics and Mining Sciences | Year: 2010

An excavation damaged zone (EDZ) around emplacement boreholes for radioactive waste represents a potential pathway for radionuclides due to its increased porosity and crack permeability. As clay is one of the potential host rocks for radioactive waste disposal, Opalinus clay samples from the underground rock laboratory at Mont Terri were investigated regarding their hydraulic properties - and related crack occurrence - after excavation and during stress-dependent crack closure. After determination of their hydraulic properties in untreated conditions, the samples were artificially cracked by tensile strength tests. The cracked samples were put into a triaxial pressure cell and the permeability and effective porosity were measured during stepwise increase and decrease of confining pressure. When the pressure was increased, a continuous decrease of permeability was found, which was similar for all test samples, and a mathematical expression was identified. When the pressure was decreased, no increase of permeability was observed until the samples were completely depressurized, leading to the assumption that during pressurization some kind of sealing process took place resulting in a permanent crack closure. In addition to the dependence on pressure, a time-dependent permeability reduction and thus crack closure at constant pressure was found, indicating a creep compaction behaviour of the clay. By knowing the initial permeability immediately after excavation of an emplacement borehole, the permeability reduction due to time-dependent stress variation can be calculated for use in long-term safety analyses. © 2009 Elsevier Ltd. All rights reserved.


Von Berlepsch T.,DBE Technology GmbH | Haverkamp B.,DBE Technology GmbH
Elements | Year: 2016

Rock salt formations can make suitable hosts for the disposal of highlevel radioactive wastes. The performance of salt as a host rock for a repository over million-year timescales has been investigated for the potential site for a geological repository at Gorleben in Germany. The main threat towards the stability of a natural salt barrier is its high solubility. Hence, prevention of water access into the waste emplacement area has to be ensured. Geological factors to be assessed in this context include diapirism, the formation of (future) glacial channels, the impact of loads and stresses imposed by glaciers, hydrocarbons, and the local hydrogeology. The disadvantages of salt are, however, outweighed by its beneficial properties: high thermal conductivity, good hydro-mechanical properties, and a tendency to creep and thus seal cracks. These characteristics make rock salt a very attractive candidate to host a geological repository for essentially all kinds of radioactive waste. © 2016 by the Mineralogical Society of America.


Muller-Hoeppe N.,DBE Technology GmbH | Schmidt H.,DBE Technology GmbH
Mechanical Behavior of Salt VIII - Proceedings of the Conference on Mechanical Behavior of Salt, SALTMECH VIII | Year: 2015

In former times, grouting measures in rock salt were applied in case brine was intruding. However, due to the lack of knowledge that the site-specific conditions were essential to control the injection procedure, the success of the grouting measures varied. In accordance with present knowledge, the injection procedure can be optimized by selecting suitable grouting material and by defining the technical parameters of the injection process. This fact implies that the limits of successful grouting measures are defined by the site-specific conditions. © 2015 Taylor & Francis Group, London.


Engelhardt H.-J.,DBE Technology GmbH | von Borstel L.E.,DBE Technology GmbH
Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften | Year: 2014

Alkaline sodium silicate solutions, also known as water glass, are a combination of sodium oxide, silica and water. The solutions react with soluble salts and brines which induce the formation of solids. The solutions have a long history of use as a particle-free grout to seal pathways for fluids in rocks and building materials. The applications demonstrate the ability of sodium silicates to seal active brine intrusions. For the grouting of rock salts it was necessary to prove the long-term stability of the reaction products. The investigations showed a formation of silicate phases and halite. In contact with MgCl2- dominated brines or MgCl2 containing minerals, e.g. bischofite or carnallite, the main additional reaction products are magnesium oxichlorides. The silicates and oxichlorides are characterised by a very low solubility, and halite is insoluble in the brines. Accordingly, sodium silicate solutions are capable to seal rock salts permanently.


Jobmann M.,DBE Technology GmbH | Meleshyn A.,GRS Society for plants and Reactor Safety
Mineralogical Magazine | Year: 2015

DBE TECHNOLOGY, BGR and GRS are developing a methodology to demonstrate the safety of a repository for high-level waste and spent fuel (HLW/SF) in clays according to the requirements of the German regulating body. In particular, these requirements prescribe that the barrier effect of host rocks must not be compromised by a thermal impact resulting from HLW/SF emplacement. To substantiate and quantify this requirement, we carried out a literature survey of research on thermally-induced changes on clay properties. Effects thus compiled can be divided into thermo-hydro-mechanical and chemical-biological-mineralogical effects and were analysed with regard to their relevance to the integrity of clay host rocks. This analysis identified one effect of major influence within each group: thermal expansion and compaction as well as results of microbial activities. Importantly, it further revealed that a moderate temperature increase above 100°C cannot be expected to compromise the integrity of the geological barrier according to the current knowledge state. Evidence is presented in this paper that temperature increases up to 150°C can actually contribute to an improved performance of a radioactive waste repository by increasing the consolidation of the clay and sterilizing the repository's near-field to depress the deteriorative microbial effects. A quantitative temperature criterion for thermal impact of HLW/SF on clay host rocks is accordingly proposed. © 2016 by Walter de Gruyter Berlin/Boston.

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