Experiments on CO2-water-rock interaction at hydrothermal temperatures have been performed to investigate dissolution and precipitation phenomena, including Ca extraction from rocks that might occur during CO2 sequestration into geothermal fields. Distilled water samples were exposed to a CO2 atmosphere at a temperature of 25°C and pressures up to 6 MPa. The resulting solutions were then reacted with granodiorite samples from the Ogachi hot/dry rock field and labradorite, at 200°C and 120°C respectively. The calcium concentrations in the solutions that had reacted with CO2 were twice those with N2 instead of CO2. Combined with the results of thermodynamic calculations, these observations indicate that calcium can be released from rocks (silicates) easily and might be removed as CaCO3 and/or CaSO4 during CO2 sequestration into geothermal fields.
UK Nirex Limited (Nirex) is investigating a site at Sellafield in Cumbria to assess its suitability as a host formation for a deep disposal facility for solid low and intermediate level radioactive waste. As part of the evaluation process, extensive characterization work has been performed. This characterization has included the acquisition of various types of information and data from the area around the site, and the use of this information in developing an understanding of the groundwater flow regime at Sellafield. Modelling the groundwater flow processes at the site is an important input to assessing the performance of the site as a host for a radioactive waste repository.
This report presents a critical review of the international literature on microbial effects
in and around a deep geological repository for higher activity wastes. It is aimed at
those who are familiar with the nuclear industry and radioactive waste disposal, but
who are not experts in microbiology; they may have a limited knowledge of how
microbiology may be integrated into and impact upon radioactive waste disposal
safety cases and associated performance assessments (PA).
Ontario Power Generation (OPG) is proposing to build a Deep Geologic Repository (DGR) for Low and Intermediate Level Waste (L&ILW) near the existing Western Waste Management Facility at the Bruce nuclear site in the Municipality of Kincardine, Ontario. The Nuclear Waste Management Organization, on behalf of OPG, is preparing the Environmental Impact Statement (EIS) and Preliminary Safety Report (PSR) for the proposed repository.
The postclosure safety assessment evaluates the long-term safety of the proposed facility and provides supporting information for the EIS and PSR.
This report describes the DGR system and its evolution under a range of possible scenarios that might affect the system in the future. The DGR system comprises the waste and its packaging, the engineered repository, its geological setting, and the surface environment.
Evidence to date indicates that leakage is of low probability if site selection, characterisation and storage project design are undertaken correctly. In Europe, the Storage Directive (EC, 2009) provides a legislative framework, implemented by Member States, which requires appropriate project design to ensure the storage of CO2 is permanent and safe. However, it is incumbent on storage site operators to demonstrate an understanding of the potential impacts on surface ecosystems should a leak occur. The RISCS (Research into Impacts and Safety in CO2 Storage) project has produced a Guide to potential impacts of leakage from CO2 storage (the 'Guide'). RISCS assessed the potential effects of CO2 leakage from geological storage on both onshore and offshore near-surface ecosystems and on potable ground water. This assessment was achieved through laboratory and field experiments, through observations at sites of natural CO2 seepage and through numerical simulations. The Guide summarises some of the key findings of the project. The Guide provides information on the best approaches to evaluate potential impacts of hypothetical leakage from CO2 storage sites and to provide guidance on appraising these impacts. This information will be relevant to regulators and operators in particular, but also to other stakeholders who are concerned with CO2 storage, such as national and local governments, and members of the public.
This paper describes the problems associated with the underwater transmission from an offshore generating station, Included is a description of the cable requirements, types of cables proposed by suppliers and the research and development required in order to optimize the cable installation.