The quantitative assessment of damage to the environment in major accidents caused by natural events

The release of hazardous materials induced by natural events affecting industrial facilities presents peculiar characteristics because of the huge potential extension of the affected areas. The reduction of both the likelihood and the magnitude of such events represents an essential step to reduce the risk associated with Natech accidents. Nevertheless, the evaluation of damage to the environment in Natech events has been poorly addressed. In the present study, past accidents analysis was carried out, using both a detailed description of specific accidents and an extended database of Natech events. Lessons learnt as well as possible common patterns and main features related to such accidents were identified and discussed. The results of the present study can be intended as a preliminary step for the development of models for the quantitative assessment of damage to the environment in major accidents caused by natural events

Risk of Subsea Blowouts in Marine CCS

In the foreseeable future, Carbon dioxide Capture and Sequestration (CCS) technique represents a promising method to contribute to the fulfilling of the ambitious objectives of carbon dioxide (CO2) emission reduction posed by the European Commission (EU). The permanent storage of CO2 is a step in the CCS chain that is of great concern due to the possibility of major accidents that could harm both humans and the environment. In the Adriatic Sea, the perspective of reusing depleted natural gas fields to stock CO2 has become more and more appealing since it provides a competitive option to reduce emissions in the short term. With that comes the need to estimate the risk of potential CO2 leakage events, particularly of blowout scenarios, which are one of the main hazards in CO2 injection due to the potential extended duration and high flow rate of the release. Thus, in the present study an assessment of the effects of CO2 blowouts in shallow water has been performed, identifying a set of models and tools available for the analysis of the consequences of subsea gaseous leakages and applying them to specific case studies. The aim of the current investigation is to highlight the specific aspects of the risk profile of CO2 blowouts with respect to those of natural gas, considering that the risk of gas blowouts is not new and has previously been effectively controlled and managed in areas where natural gas reservoirs were exploited

Assessment of the risk related to environmental damage following major accidents in onshore pipelines

Major accidents may cause both direct damages to the exposed population and damage to the environment, indirectly affecting the population by the contamination of land, surface water and groundwater. A wide attention was paid to date to the assessment of the direct risk for the population deriving from major accidents (fires, explosions, toxic releases). Less work was devoted to the quantitative assessment of the risk due to the environmental consequences of major accidents. In the present study, an innovative GIS-based approach was developed for the quantitative assessment of the risk caused by damage to the environment deriving from major accidents involving pipelines. The method allows the calculation of local and overall environmental risk indexes, expressed both in physical and monetary terms. These are structured so that in perspective they can be combined with the risk obtained for the exposed population, providing a comprehensive risk figure of the potential consequences of major accidents involving oil pipelines. A specific software tool was developed to support the application of the methodology. A real-life case-study is presented and discussed in order to assess the potentiality of the approach. The results confirm that, in the frame of safety guidelines and good practices for pipelines, the proposed methodology represents a useful tool to fulfil requirements concerning the comprehensive risk assessment of pipeline operation, providing useful information on safety-critical segments and on the expected severity and economic impact of spill scenarios. © 2018 Elsevier Lt

A methodology for the analysis of domino and cascading events in Oil & Gas facilities operating in harsh environments

The present study is aimed at defining a structured approach to the quantitative assessment of cascading events triggered by fire, accounting for the influence of harsh environmental conditions on the emergency response and on the performance of hardware safety barriers. A specific metric was defined in order to consider the external factors related to harsh environments on the determination of hardware and emergency safety barriers availability, with a specific focus on operations in extremely cold climates. The metric allows evaluating the time scale of emergency and the related efficiency of barriers in contrasting accident escalation. The values obtained for availability and effectiveness of barriers were input to a specific event tree analysis in order to support the quantitative assessment of accident frequency associated to cascading events. The approach is tested by its application to a case study, aimed at the assessment of the influence of extremely cold environmental conditions on the risk due to cascading events in an industrial site

Assessment of the risk related to environmental damage following major accidents in onshore pipelines

none3noMajor accidents may cause both direct damages to the exposed population and damage to the environment, indirectly affecting the population by the contamination of land, surface water and groundwater. A wide attention was paid to date to the assessment of the direct risk for the population deriving from major accidents (fires, explosions, toxic releases). Less work was devoted to the quantitative assessment of the risk due to the environmental consequences of major accidents. In the present study, an innovative GIS-based approach was developed for the quantitative assessment of the risk caused by damage to the environment deriving from major accidents involving pipelines. The method allows the calculation of local and overall environmental risk indexes, expressed both in physical and monetary terms. These are structured so that in perspective they can be combined with the risk obtained for the exposed population, providing a comprehensive risk figure of the potential consequences of major accidents involving oil pipelines. A specific software tool was developed to support the application of the methodology. A real-life case-study is presented and discussed in order to assess the potentiality of the approach. The results confirm that, in the frame of safety guidelines and good practices for pipelines, the proposed methodology represents a useful tool to fulfil requirements concerning the comprehensive risk assessment of pipeline operation, providing useful information on safety-critical segments and on the expected severity and economic impact of spill scenarios. © 2018 Elsevier LtdmixedBonvicini S., Antonioni G., Cozzani, V.Bonvicini S., Antonioni G., Cozzani, V

Quantitative assessment of environmental risk due to accidental spills from onshore pipelines

The transport of hazardous materials by pipeline is widely used for the transfer of significant quantities of oil and chemicals. Due to the extremely low frequency of spills, pipelines are considered the safest mode for the land transportation of hazardous substances. Accident records, while confirming that Loss Of Containment (LOC) events are rare, also point out the major-accident hazard of pipelines, due to the extremely severe potential consequences of spills. Quantitative Risk Analysis (QRA) techniques have been applied to pipelines since many years with the aim of evaluating risk for workers or exposed population. However, releases of liquids, as oil and oil products, also create an hazard to the environment, due to the potential of extensive soil and groundwater contamination. An integrated model was developed for the environmental risk analysis of spills from pipelines. Specific environmental risk indexes were defined, expressing the risk of soil and groundwater contamination, both in physical and economic terms. A case-study is presented and discussed to illustrate the features of the methodology. The results confirmed that the proposed model may be considered an important tool within a comprehensive approach to the management of risk related to onshore pipelines

Threshold-Based Approach

Escalation thresholds are widely used as a baseline approach to the assessment of the hazard posed by domino scenarios. These should be intended as conservative values of physical effects (thermal radiation, maximum overpressure, etc.) below which the escalation is deemed not credible. The present section deals with this preliminary approach to domino hazard assessment, revising the values provided in the literature for escalation thresholds and providing suggested values based on recent results obtained in the revision of past accident data and in the modeling of equipment damage