(162e) A Study on Quantitative Risk Assessment Model for Lng Storage Tank I

This study presents a standard QRA (Quantitative Risk Assessment) model for LNG storage tank, which consists of several analysis modules that are linked together. While the major modules are FAM (Frequency Assessment Module) and CAM (Consequence Assessment Module), each of them could be used independently as a subordinate assessment model. The risk related to LNG storage tank could be determined by risk matrix, F-N curve, societal risk or individual risk based on the results from operation of the two major modules.

FAM is divided into two parts based on LNG release event as its starting point; one is FTA (Fault Tree Analysis) for cause analysis, and the other is ETA (Event Tree Analysis) for consequence determination.

The actual case study for Korean LNG storage tanks has been also performed considering accident types decided through consequence determination of ETA. This case study enabled us to identify the outcomes from probable accidents such as jet-fire, pool-fire, flash-fire, VCE and BLEVE with their probability, and individual risk of them. The consequence was estimated based on the worst weather condition. Asphyxiation injury or facility damage caused by lack of oxygen and cryogenic exposure after release of LNG was excluded in consequence assessment of this study, but these two aspects must be considered in hazard evaluation of LNG storage tank.