Investigators have concluded that a ruptured pipe is to blame for an explosion and fire at the Co-op crude oil refinery in Regina last Christmas Eve.
An investigation determined that a bypass line froze and ruptured following a maintenance procedure on a polymerization unit, which is used to make gasoline.
Once the air temperature warmed, petroleum product was released through the line, resulting in an explosion and subsequent fire, Federated Co-operatives Limited said in a news release Wednesday.
No one was injured and everyone was accounted for after the Christmas Eve blast, which was heard and felt around Regina and surrounding areas.
Investigations into the incident were undertaken by the Regina Fire Department and the Technical Safety Authority of Saskatchewan. Co-op also conducted its own internal review.
It was the fourth fire in about two years at the refinery.
In February, a fire in a coker unit sent flames shooting nearly 20 metres in the air, but was quickly brought under control.
In October 2011, corrosion in a pipe triggered a fireball that sent seven contract workers to hospital and forced 1,400 workers from the facility.
In May 2012, a much smaller fire occurred when an overheated crude oil pump ignited. There were no injuries.
