The U.S. Chemical Safety Board (CSB) team investigating an explosion at the Husky Energy oil refinery in Superior, Wisconsin has narrowed its focus to equipment within the refinery’s Fluid Catalytic Cracking, or FCC, unit. The April 26, 2018 blast injured approximately 20 employees and caused an evacuation of residents in the surrounding area.
When the incident occurred, the refinery was preparing to enter a 5-week maintenance turnaround, during which time equipment is shut down so that it can be opened, inspected, and repaired as needed. The initial explosion took place within the FCC unit, which “cracks” heavy, high boiling point hydrocarbon molecules into smaller molecules with lower boiling points. CSB is reviewing documentation pertaining to the FCC unit.