Hazards related to transportation and storage of Liquefied Natural Gas (LNG) are widely studied due to an increasing importance of LNG in the overall energy supply. Large scale LNG spills on water are of particular interest as much of LNG transport is conducted by sea. The present work focuses on modelling approaches and their capabilities to predict different phenomena related to LNG spills. It describes in detail a developed CFD based methodology that is able to simulate the behaviour of LNG spills from their initial release, spreading on the water surface, Rapid Phase Transition (RPT) to subsequent dispersion. The methodology is based on a homogeneous multiphase formulation of the liquid layer and therefore suitable for implementation in most of commercial CFD packages. An LNG release from a process train on a FLNG vessel was used to demonstrate capabilities of the developed approach. A CFD simulation was conducted to calculate the volume and distribution of the flammable cloud, and the overpressure generated by an RPT event. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.