It wasn’t that long ago when the Husky Energy Refinery in Superior, WI, was shutting down in preparation for a five-week turnaround when an explosion occurred, sending several people to area hospitals with injuries.
The ensuing fire after the explosion could have been worse, had it not been for a relationship between the refinery and the local fire department.
As a result, the Chemical Safety Board (CSB) issued a video showing the incident and revealing details of the relationship between the refinery and local fire department.
The initial explosion occurred April 26 in the refinery’s Fluid Catalytic Cracking Unit (FCCU) at 10 a.m. while the refinery was shutting down the FCCU for periodic maintenance and inspection, CSB investigators said.
To date the CSB has determined the following:
• The explosion took place during a planned maintenance shutdown of the refinery FCCU.
• The incident occurred during a scheduled break time and many workers previously in the unit before the explosion had moved either into blast resistant buildings or away from the process unit.
• One piece of debris from the explosion flew about 200 feet, and struck a large, nearby, aboveground storage tank containing about 50,000 barrels of asphalt. The side of the tank was punctured, resulting in the release of over 15,000 barrels of hot asphalt into the refinery.
• Approximately two hours after the release, the asphalt ignited, resulting in a large fire.
• As a result of the explosion, 36 people sought medical attention, including 11 refinery and contract workers who sustained OSHA recordable injuries. In addition, a large portion of Superior, Wisconsin, evacuated.