6.2 Risk analysis

RiskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event analysis involves interactive exchange among riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event assessors, riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event managers, regulators, local community, news media and interest groups. A qualitative type of riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event analysis should be performed at the early stages of a project to help site screening, site selection, communicating project aspects to the public, and aiding regulators in permitting projects. Subsequent to more detailed site characterisation and modelling efforts, quantitative riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event analysis may be performed to estimate the likelihood of human health and environmental risks. Furthermore, stakeholders such as regulators and insurers may require riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event analysis to support incentives, such as loan guarantees to large projects. A successful riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event analysis will always be linked to monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions and modelling plans for a given storage(CO2Carbon dioxide) A process for retaining captured CO2Carbon dioxide, so that it does not reach the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) site. The riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event analysis results can be used by industry, investors, and insurers to understand the potential liability associated with projects and build that into the cost of developing a CCSCarbon dioxide CaptureThe separation of carbon dioxide from other gases before it is emitted to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) and Storage project (NETL, 20112011 - NETLRisk Analysis and Simulation for Geologic Storage of CO2, Version 1.0see more). Once risks are understood, a project developer must take steps to avoid or manage the risks that are not judged acceptable. In the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event management step (Fig. 6-3), inputs from the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event and characterization processes, and a variety of social, political, and techno-economic parameters are used to prioritize, monitor, control and mitigate risks (NETL, 20112011 - NETLRisk Analysis and Simulation for Geologic Storage of CO2, Version 1.0see more).

It is important to distinguish between riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event and uncertainty, although they may be related (DNV, 20102010 - DNVCO2QUALSTORE - Guideline for selection and qualification of sites and projects for geological storage of CO2see more). Uncertainty is a critical factor to assess in the context of riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event/performance assessment (NETL, 20112011 - NETLRisk Analysis and Simulation for Geologic Storage of CO2, Version 1.0see more) that can be related to different features:

1. Parameter uncertainty, associated with input parameters, is commonly recognized and addressed in modelling approaches, via e.g. numbers of simulations based on a randomly sampling of uncertain parameters (Monte CarloA modelling technique in which the statistical properties of outcomes are tested by random inputs approach).

2. Conceptual model uncertainty, concerning how the real world (geological cross-sections, faults or fractures zones, etc.) is represented and abstracted.

3. Modelling uncertainty, concerning the underlying mathematical modelling and its inherent assumptions, e.g. boundary conditions. Modelling uncertainty can be assessed qualitatively by comparison of results from different mathematical models, via benchmarking exercises, which are recommended to enhance modelling credibility and confidence.

4. ScenarioA plausible description of the future based on an internally consistent set of assumptions about key relationships and driving forces; note that scenarios are neither predictions nor forecasts/event uncertainty, relating to whether scenarios/events representing all potential hazards have been identified and analysed (Stenhouse et al., 2009).

A core part of qualitative or quantitative ranking of risks for CGSCO2 Geological Storage; Injection accompanied by storage of CO2 streams in underground geological formations. involves assessing the level of knowledge available, and the subsequent implications on the level of riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event. Proper management of uncertainty helps to manage down the assessed level of riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event throughout the life of a CGSCO2 Geological Storage; Injection accompanied by storage of CO2 streams in underground geological formations. project. In particular, if risks are ranked conservatively, reducing uncertainty will generally result in a lowering of the assessed riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event (DNV, 20102010 - DNVCO2QUALSTORE - Guideline for selection and qualification of sites and projects for geological storage of CO2see more).

An important step of a detailed riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event is the qualitative or semi-quantitative prioritisation of the risks, where risks are categorised and ranked in terms of likelihood and magnitude of consequence. The ranking allows high-priority risks to be identified and plans for mitigating or controlling them to be developed, while lower-priority risks can be placed on a watch list. Other risks, with mid- or unknown-priorities, may undergo further analysis or investigation. As more information is obtained from site characterisation, modelling, and monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions, the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event priorities can be updated. Later stages may also include model simulations to assess the probabilities and impacts of selected scenarios. Such plans will heavily rely on monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions data and will generally stipulate an "if-then" process: if the monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions system detects a problem, then specific actions will be performed to address the problem, either immediate action or need for an additional, focused monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions. A good monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions and mitigationThe process of reducing the impact of any failure plan will decrease the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event and uncertainty associated with many potential consequences (NETL, 20112011 - NETLRisk Analysis and Simulation for Geologic Storage of CO2, Version 1.0see more).