TransCanada Energy Ltd. (TC Energy) – Request to Return to Service at Maximum Operating Pressure (MOP) Mainline (ML) 100-4, Mainline Valve (MLV) 2-9
File OF-Surv-Inc-2013 150
3 November 2020
Ms. Leslie Kass
Manager, Canadian Regulatory
Senior Vice President, Technical Centre
450 1st Street SW
Calgary, AB T2P 5H1
Dear Ms. Kass:
TransCanada Energy Ltd. (TC Energy)
Request to Return to Service at Maximum Operating Pressure (MOP)
Mainline (ML) 100-4, Mainline Valve (MLV) 2-9
Safety Order SG-T211-002-2014
Amended Order AO-001-SG-T211-002-2014
On 9 October 2020, the Commission of the Canada Energy Regulator (Commission) received a request from TC Energy to return pipeline segment ML 100-4, MLV 2-9, to its licensed MOP of 6065 kPa. The operating pressure of this segment was restricted by Safety Order SG-T211-002-2014, issued by the National Energy Board (NEB) on 10 April 2014 and amended on 17 April 2014. On 28 August 2019, the Canada Energy Regulator (CER) replaced the NEB and all orders issued by the NEB are considered to have been made under the Canadian Energy Regulator Act (CER Act)and may be enforced as such.Footnote 1
With its request, TC Energy submitted a revised Engineering Assessment (EA) to demonstrate that the pipeline segment is fit to return to service and to outline additional integrity activities that would enhance safe operations. An EA had been previously submitted to the CER on 20 July 2020. The EA was the subject of assessment and informal information exchanges between CER staff and TC Energy until such time as TC Energy filed the revised EA.
The Commission has considered the information provided in the revised EA and acknowledges that significant In-Line Inspection (ILI), ILI validation excavation and remediation to the pipe has taken place on the pipeline segment over the last two years. The Commission understands that the predominant threats to the pipeline’s integrity are external corrosion, Stress Corrosion Cracking (SCC) and construction anomalies, all of which are being managed by TC Energy. The threats posed by external corrosion and SCC have been mitigated and pipe condition monitoring will continue through ILI at appropriate intervals. TC Energy, in its EA, has asserted that construction anomalies, such as girth weld cracks or crack like anomalies, will remain stable at MOP and are unlikely to fail in the absence of significant stresses.
The Commission finds that the information presented in the supporting EA demonstrates that the pipeline segment is fit for service at its MOP. Pursuant to Condition 1 of Safety Order SG-T211-002-2014, the Commission approves TC Energy’s request to increase the operating pressure of the pipeline segment to service at its licensed MOP of 6065 kPa. As all the conditions of the Safety Order have now been satisfied, the Safety Order has no further effect.
Original signed by
Secretary of the Commission
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