As Low As Reasonably Practicable (ALARP) demonstration is a continuous process in ensuring risks are managed in all phases of a project lifecycle (i.e. Assess to Operate phase). However, there is often a misconception that risks reported within the ALARP region are misinterpreted as representing acceptable risk levels or risk levels that are ALARP. It is important that risks reported within the ALARP region of any risk tolerability framework should only be deemed acceptable or tolerable once it has been demonstrated that all reasonably practicable risk reduction measures have been implemented. INPEX has developed a systematic process for ALARP demonstration and this paper discusses the ALARP demonstration for the installation of firewater curtain for the Liquefied Petroleum Gas (LPG) sphere at the LNG regasification terminal. Hazard assessment conducted in the design phase were reviewed based on operating experience and parameters and consequence assessment were re-modelled using Potential Hazard Analysis Software Tool (PHAST). Consequence assessment revealed that for release size 25mm and above, the gas cloud dispersion and radiation distance could exceed the plant distance separation distance of 65m. This research also points out the limitation of consequence modelling using PHAST. Installation of firewater curtain does not provide additional risk reduction outweighing the expenditure required for firewater curtain installation. Existing risk reduction strategy and measures put in place are enough to control the residual risk arising from LPG sphere.