Assessment of the impact of an unconfined vapour cloud explosion at a major hazard facility in Melbourne close to a large proposed housing development

Abstract

An increasing problem in Australia is the encroachment of residential areas into former industrial zones near to operational Major Hazard Facilities (MHFs). The consequences of scenarios such as unexpected UVCE or Unconfined Vapour Cloud Deflagration (UVCD) events can be catastrophic with significant loss of life and extensive property damage. They follow from the formation of clouds of gases and vapours resulting from accidental release of flammable liquids or pressurised heavier–than–air flammable gases and their subsequent ignition. The paper describes superimposition of the published 2005 UK Buncefield accident overpressure contours on the Gellibrand Tank Farm (GTF) in Williamstown and presents the findings of a targeted CFD modelling study. The modelling was limited by absence of data for the GTF. The purpose of the work is to emphasise the need for a full and independent quantified risk assessment study to be performed as would be required in the UK, with respect to a major housing development proposed on former nearby industrial land.