No injuries were reported and there was no disruption to operations after a small explosion at the Tesoro Alaska Petroleum Co. refinery in Nikiski early Wednesday afternoon.
Company spokesperson Ron Noel in Anchorage said welders were installing a metal liner in an oily water drainage canal at the time of the explosion.
"At this time I can't tell you exactly what happened, but vapors may have traveled along (the canal) and ignited in the sump," Noel said.
He said the explosion in the lead-lined underground sump chamber was like a flash fire.
"It made a big 'whump' noise," Noel said.
He said there was no subsequent fire associated with the blast and operations at the refinery were not affected.
"There were no injuries, no fire and no spill," Noel said. "The plant is all clear, and the refinery manager is investigating the incident."
The Nikiski Fire Department responded to the blast, but returned to base shortly after arriving. No department spokesperson was available to comment.
Noel said there is a procedure in place for the company to follow after an incident like this, and the investigation into exactly what happened is ongoing.
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