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Visar resultat 1 - 5 av 19 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Maturation of Clay Seals in Deep Bore Holes for Disposal of Radioactive waste : Theory and Experiments

   Författare :Ting Yang; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-level radioactive waste; HLW; very deep borehole; VDH; disposal; saturation degree; water transport; maturation; model; shear strength; hydraulic conductivity; swelling pressure; homogenization; Geoteknik; Soil Mechanics;

   Sammanfattning : KBS-3 and very deep borehole (VDH) concepts are two major types of long-term geologicaldisposal methods for high-level radioactive waste (HLW) isolating from the biosphere. TheKBS-3V concept for isolating the HLW at the depth of 400-500 m, is the officially proposedoption in Sweden and has been the subject of considerable research in the past few decades,while the VDH concept was considered as an option in the 1950s but later became discouragedbecause of insufficient experience in drilling technology. LÄS MER

3. 2. Numerical modeling of groundwater and air flow between compacted bentonite and fractured crystalline rock

   Författare :Benoît Dessirier; Jerker Jarsjö; Andrew Frampton; Stefan Finsterle; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Two-phase flow; porous media; fractured media; compacted bentonite; crystalline rock; numerical modeling; geological disposal; Physical Geography; naturgeografi;

   Sammanfattning : The geological repository for final storage of spent nuclear fuel, envisioned by the Swedish Nuclear Fuel and Management Company (SKB), relies on several barriers: copper canisters deposited in holes in the floor of underground tunnels in deep bedrock, embedded in a buffer of compacted bentonite. The initially unsaturated buffer would take up water from the surrounding rock mass and swell to seal any potential gap. LÄS MER

4. 3. The complexation of some radionuclides with natural organics : Implications for radioactive waste disposal

   Författare :Maria Nordén; Linköpings universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

   Sammanfattning : Natural organics like humic substances are important for the speciation, mobility and bioavailability of metals in the environment. This ability necessitates the investigation of what impact humic substances may have on radionuclides that accidentally can escape from radioactive waste repositories. LÄS MER

5. 4. Borehole sealing with expandable buffer clays in HLW disposal : Lab-scale performance

   Författare :Ting Yang; Jörn Kasbohm; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soil Mechanics; Geoteknik;

   Sammanfattning : Two basically different multibarrier concepts for high-level radioactive waste (HLW) are the often cited KBS-3 V/H concepts, for isolating nuclear waste at 400-600 m depth and Very Deep Boreholes concepts (VDH) for placement at 2000-4000 m depth. Both make use of expandable clay as isolating medium of canisters with HLW and as backfill material in shafts and tunnels in repositories for safe disposal of such waste. LÄS MER

7. 5. Fractured Rock Masses as Equivalent Continua - A Numerical Study

   Författare :Ki-Bok Min; KTH; []
   Nyckelord :fractured rock masses; equivalent continuum; discrete fracture Network DFN ; Distinct Element Method DEM ; Finite Element Method FEM ; Nuclear Waste Disposal; Coupled Thermo-Hydro-Mechanical Processes;

   Sammanfattning : In this thesis, fractured rock masses are treated asequivalent continua for large-scale analyses of rockengineering projects. Systematic developments are made for thedetermination of equivalent mechanical and hydraulic propertiesof fractured rock masses using a hybrid discrete fracturenetwork - distinct element method (DFN-DEM) approach. LÄS MER