Applying Inherent Safety to Mitigate Offsite Impact of a Toxic Liquid Release

摘要

A chemical plant site has a large storage tank containing a regulated toxic and flammable material that consequence modeling indicated a potential for significant offsite impact in the event of a large release. The initial modeling analysis indicated that high evaporation rates from the large pool surface area inside the containment dike were the major factor in the offsite impact. Although monitoring devices will detect any leakage from the tank, the site wanted to reduce the potential for offsite impact and the need for any offsite emergency response measures. The site made modifications to reduce the effective surface area inside the containment dike. Additional consequence modeling was conducted for the new design under worst case scenario conditions. This paper discusses the approach used to reduce the offsite potential of a large spill, including the initial evaluations, the design modifications, and the final results. The final dispersion analyses indicate that offsite impact will not occur and offsite response will not be required. Only onsite response will now be required to handle any range of releases at the facility.