A5009155723- Soil and Unsaturated Flow
- Groundwater flow and contamination studies
- Nuclear and radioactivity studies
- Graphite, nuclear technology, radiation studies
- Concrete and Cement Materials Research
- Clay minerals and soil interactions
- Radioactive element chemistry and processing
- Nuclear Materials and Properties
- CO2 Sequestration and Geologic Interactions
- Radioactive contamination and transfer
- NMR spectroscopy and applications
- Hydraulic Fracturing and Reservoir Analysis
- Environmental Policies and Emissions
- Landfill Environmental Impact Studies
- Nuclear materials and radiation effects
- Groundwater and Isotope Geochemistry
- Nuclear reactor physics and engineering
- nanoparticles nucleation surface interactions
- Minerals Flotation and Separation Techniques
- Research in Social Sciences
- BIM and Construction Integration
- Vehicle emissions and performance
- Asphalt Pavement Performance Evaluation
- Grouting, Rheology, and Soil Mechanics
- Analytical chemistry methods development
VTT Technical Research Centre of Finland
1999-2024
Tieto (Finland)
2020
University of Helsinki
1986-2006
Chalmers University of Technology
1995
Abstract Data science (digitalisation and artificial intelligence) became more than an important facilitator for many domains in fundamental applied sciences as well industry is disrupting the way of research already to a large extent. Originally, data were viewed be well-suited, especially, data-intensive applications such image processing, pattern recognition, etc. In recent past, particularly, data-driven physics-inspired machine learning methods have been developed extent that they...
Mass and elemental concentrations of particles were determined in indoor outdoor air urban suburban Helsinki, Finland. The effects outdoor-to-indoor transport sources on particle studied detail. Resuspension deposition to surfaces also investigated. experimental results are used develop specify an aerosol physical model for behavior air, which is presented at the end.
Abstract The swelling and cation exchange properties of montmorillonite are fundamental in a wide range applications ranging from nanocomposites to catalytic cracking hydrocarbons. results several factors and, though widely studied, information on the effects single factor at time is lacking. In this study, density functional theory (DFT) calculations were used obtain atomic-level montmorillonite. Molecular dynamics (MD) was investigate montmorillonites with different layer charges...
Abstract Bentonite clay is planned to form a part of deep-geological repositories spent nuclear fuel in several countries. The extremely long operation time the repository requires an indepth understanding structure and properties used materials. In this work microstructure simplified system Ca-montmorillonite investigated using set complementary methods: X-ray diffraction, small angle scattering, magnetic resonance, transmission electron microscopy ion exclusion. paper presents experimental...
Abstract The planned final disposal repositories of spent nuclear fuel in several countries, including Finland, pose significant scientific challenges due to their extremely long lifespan. One the key materials proposed for use Posiva Oy's repository Finland is MX-80 bentonite a compacted, water-saturated state. Border cases calcium and sodium forms purified were included this study. expected undergo cation exchange composition groundwater. clays studied at different dry densities between...
Baryte (BaSO4) is a critical raw material with no functional recycling since the used applications are dissipative. Significant quantities of baryte end up in tailings as side stream from mining industry. secondary source was filler plastics for low duty radiation shielding and an aggregate geopolymers needed safely storing low-radioactive waste ash. Mechanical strength remained at high level 0–50 % additions. Low-cost plastic composites additions showed promising attenuation X-rays...
Summary Experimental data for uranium adsorption on a complex weathered rock were simulated by twelve modelling teams from eight countries using surface complexation (SC) models. This intercomparison was part of an international project to evaluate the present capabilities and limitations SC models in representing sorption geologic materials. The assessed terms their predictive ability, requirements, number optimised parameters, ability simulate diverse chemical conditions transferability...
Abstract Compacted bentonite is to be used as a buffer material between waste canisters and the bedrock in deep geological disposal of high-level nuclear several countries. In spite fact that such large systems have long equilibration times, estimation properties performance repository conditions often based on short-term, laboratory-scale experiments. Sample-preparation procedures these experiments may differ from natural evolution repository, however, affecting properties. The present...
Copper canister is a central technical barrier for radioactive release from high level nuclear waste in the so called KBS-3 concept planned to be used Finland and Sweden disposal of spent fuel. Canisters will placed granitic bedrock at about 400–500 m depth surrounded by layer bentonite clay protect any chemical mechanical damage, especially acting as diffusion barrier. While researching possibility stress corrosion cracking phosphorus microalloyed copper presence sulphides groundwater,...
Safe management of radioactive waste is challenging to producers and organisations. Deployment thermal treatment technologies can provide significant improvements: volume reduction, passivation, organics destruction, safety demonstration facilitation, etc. The EC-funded THERAMIN project enables an EU-wide strategic review assessment the value applicable Low Intermediate Level streams (ion exchange media, soft operational waste, sludges, organic liquids). compiles database wastes, which could...
Deep geological disposal aims to contain and isolate radioactive waste from the biosphere. Repository systems are made of multiple barriers working together, typically comprising natural barrier provided by repository host rock its surroundings an engineered system. Due their excellent properties for confinement contaminants, including low permeability, high sorption capacity, swelling/self-sealing clayey materials considered as and/or in most designs under development Europe. During...
Finnish spent nuclear fuel final disposal is planned to be based on the Kärnbränslesäkerhet 3-Vertical concept, which was originally for fractured crystalline bedrock. Within this role of bentonite buffer considered central. The aim study model evolution repository during thermal phase (heat-generating period fuel) when initially only partially saturated. There an essential need determine how temperature influences saturation and both these factors affect chemistry bentonite.In Long-Term...
For the safe final disposal and/or long-term storage of radioactive wastes, deep or near-surface underground repositories are being considered world-wide. A central safety feature is prevention, sufficient retardation, radionuclide (RN) migration to biosphere. To this end, sorption one most important processes. Decreasing uncertainty in may contribute significantly reducing overall a performance assessment (PA). PA, typically characterised by distribution coefficients ( K d values). The...
Abstract VTT has developed a gasification-based technology for processing low- and intermediate-level waste (LILW) rich in organic matter. VTT’s process is based on well-controlled thermal fluidised-bed gasification followed by efficient gas cleaning, conditioning/oxidation, wet scrubbing of the oxidised (flue gas), finally, filtering through high efficiency particulate air (HEPA) filter, which acts as backup cleaning system. In case an ion exchange resin (IXR) primary product from fine...