GATINEAU, QC, June 4, 2013 /CNW/ - The Transportation Safety Board of Canada (TSB) has concluded in its investigation report (P12H0105) that a pre-existing flaw in the pipe was the primary cause of a Westcoast Energy Inc. pipeline explosion that occurred on 28 June 2012, approximately 40 km northwest of Buick, British Columbia.
On 28 June 2012, the 16-inch Nig Creek pipeline ruptured; gas escaping from the ruptured pipeline ignited, and the resulting fire spread to the surrounding forested area. Approximately 25 minutes later, the 6.625-inch Bonavista Energy Corporation pipeline, located 3 meters away in the same right-of-way, ruptured due to its exposure to the fire, and the escaping gas also ignited.
The TSB investigation found that certain types of pipe welded using a low-frequency electric resistance welding technique have an increased likelihood for the presence of defects such as cracks, and that this increases the risk that the pipe might fail. Following the accident, the National Energy Board directed Westcoast to conduct necessary integrity assessments and repairs prior to seeking approval to return the pipeline into service.
Since the accident, Westcoast Energy Inc. has taken a number of actions aimed at ensuring the integrity of its pipeline. It has conducted a successful pressure test on the entire Nig Creek pipeline, and filed a monitoring and verification plan for the pipeline's fitness for service with the National Energy Board. It has also commissioned additional metallurgical analysis of other segments of the pipeline and scheduled an extensive inspection of the pipeline from the inside. Further, the company has begun a pipeline control room management review. It is anticipated that the resulting changes will improve response times during an emergency.
The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
SOURCE: Transportation Safety Board of Canada
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