Consequences of LNG Marine Incidents

The LNG industry in the US is currently facing challenges obtaining approvals for new receiving terminals. A factor of concern at public meetings relates to the potential hazards associated with marine transport accidents or terrorist events. The purpose of this study is to develop a range of well conceived maximum credible failure cases from accidental or terrorism causes and to predict hazard zones using a well validated model. Hazard zones that are presented in this paper tend to fall below many of the values previously quoted. While additional experimental trials may be warranted, current results are of sufficient confidence to draw valid conclusions. Currently there are 5 import and 1 export LNG terminals in the US including Puerto Rico. There are over 30 proposed developments in the US and in nearby parts of Canada and Mexico. While a small number of new terminals have been approved or are proceeding through the approval process, a number have failed to go forward and local opposition to LNG has developed. Part of the public objections relate to safety concerns about the potentially large consequence zones for LNG shipping incidents. While some of these estimates have been based on non-credible assumptions and inappropriate models, others have been based on sound assessments but with overly pessimistic assumptions. The objective of this paper is to review the range of potential LNG marine spillage events from collision, grounding, operational error, and terrorism. The identification of credible hole sizes for loss of containment events is based on a review by specialists knowledgeable in all aspects of the LNG transport activity. Credible in this context means those events whose precursors are technically feasible but still highly unlikely within a future context of LNG activity in the US - 30 terminals, 30 years, 100 visits/year. The consequences from maximum credible events are assessed, regardless of their likelihood - none of which have occurred in the 40 years of LNG shipping and many of which will be extremely unlikely given the excellent