Security Vulnerability Assessment Of A Hypothetical Lng Gas Treating Plant Using A Spreadsheet Template

Abstract

The upsurge of terrorism and attacks on chemical plants in several nations, including Nigeria, has necessitated the need for vulnerability studies. This study uses the Security Vulnerability Assessment, Prevention, and Prediction approach to analyze the vulnerabilities of a hypothetical chemical plant using a developed spreadsheet template. With a safety barrier method, an attack model based on security barriers was developed. External, internal, interior, critical, and fail-safe security barriers were proposed to help avert an attack, coupled with two supervisory barriers (political and management & organization) to influence the process at every event. The security barriers prior failure were calculated using fault tree and Bayesian inference combined with the Noisy-AND model. The consequences of various event scenarios were evaluated using event tree analysis. Comparison of results from spreadsheet template with those from literature indicate that it is reasonably accurate for vulnerability calculations. The prior failure probability of the Critical (1.59%) and Political (3.17%) barriers are the same. Sensitivity analysis showed that the security barriers’ have an impact on the consequences. The External (6.446%) and Political (3.17%) barriers were the most important barriers in the attack model sequence, with both having a high failure probability. Based on these results, a number of security countermeasures are proposed. These include placing guard towers around the perimeter fence and developing a security check to monitor and restrict business traffic in the plant as well as establishing and maintaining positive labor relations to mitigate the conception of disgruntled employees.