Fabio Currò

A framework for risk assessment and decision-making strategies in dangerous good transportation

The risk from dangerous goods transport by road and strategies for selecting road load/routes are faced in this paper, by developing an original site-oriented framework of general applicability at local level. A realistic evaluation of the frequency must take into account on one side inherent factors (e.g. tunnels, rail bridges, bend radii, slope, characteristics of neighborhood, etc.) on the other side factors correlated to the traffic conditions (e.g. dangerous goods trucks, etc.). Field data were collected on the selected highway, by systematic investigation, providing input data for a database reporting tendencies and intrinsic parameter/site-oriented statistics. The developed technique was applied to a pilot area, considering both the individual risk and societal risk and making reference to flammable and explosive scenarios. In this way, a risk assessment, sensitive to route features and population exposed, is proposed, so that the overall uncertainties in risk analysis can be lowered.

MATHEMATICAL MODELING OF FLUID SPRAY CURTAINS FOR MITIGATION OF ACCIDENTAL RELEASES

In this article experimental and theoretical investigations on liquid spray curtains are presented, in the context of absorbing and dispersing accidental releases of chlorine in air. A mathematical model of a two-phase jet is developed to evaluate the entrained air rate in connection with the liquid flow rate. The model was successfully compared by means of replicated wind tunnel experimental runs adopting spray nozzles suitable to create a two-blade barrier. The experimental work demonstrated that it is possible to distinguish two regions in the barrier. One region is dominated by the liquid inertia and is comparable to an airplane jet. The other region is dominated by gravitational effects, and its dimensions do not vary appreciably. An analytical solution to the problem is obtained, taking into account the instantaneous and nonreversible chemical reactions, i.e., chlorine absorption in alkaline solutions, in the case of still air. The developed methodology could be applied to more complex situations, allowing the attainment of a more generalized approach for the design of a curtain given the release parameters, the site layout, and vulnerable target specifications.

Risk assessment and decision-making strategies in dangerous good transport. From an Italian case-study to a general framework

Publisher Summary This paper discusses the risk associated with the transportation of dangerous goods by road and strategies for selecting road load/routes by developing a site-oriented framework of general applicability. A methodological approach for the assessment of standard vehicle and dangerous good truck flows was applied to a pilot area, allowing a statistical reinforced evaluation of intrinsic enhancing/mitigating parameters. In this way a risk assessment sensitive to route specifics and population exposed is proposed and the overall uncertainties by the risk analysis can be lowered. The developed model, of general applicability, can represent a useful tool not only to estimate transport risk but also to define strategies for the reduction of risk and emergency management. Poor appreciation of factors related to road conditions such as road class, designated speed limits, traffic density, as well as of the population characteristics, is likely to result in a risk assessment insensitive to route specifics and over- or under-estimating the overall level of risk. The results show that the risk associated with the transport of hazardous materials on the highway considered in the chapter is at the limit of the personally acceptable level of risk.