Transformer failure and fire causes oil spill at Churchill Falls switchyard

What happened

A transformer failure and fire at the Churchill Falls switchyard in Newfoundland and Labrador resulted in an oil spill on Thursday night, 29 October 2020, according to Nalcor Energy, the provincial Crown corporation that operates the site. The transformer held 53,000 litres of oil, which was released in the area of the switchyard. Once it was safe to do so, the company's environment team accessed the site. In a media release on Friday evening, Nalcor said crews were assessing the volume released and preparing a cleanup plan.

The oil, known as Voltesso, is a transformer oil that the company described as biodegradable over a long time period. Nalcor said there was no indication the oil had reached the Churchill River. Workers deployed booms in the river as a precaution, and a spill response team was activated along with a helicopter patrol to assess dispersion. The cause of the fire was not yet known and an investigation was under way.

Contributing factors

The source attributes the spill to a transformer failure and fire. The company said the cause of the fire was not yet known and an investigation was under way. Not reported: the volume actually released.

Lessons learned

1. Large oil-filled transformers need condition monitoring and fire protection, including oil containment and drainage, so that a failure does not become a spill.
2. Operators should pre-plan containment for each switchyard, including booms and response teams that can be activated quickly.
3. Clear early communication on the oil product, its biodegradability and the volume released helps regulators and the public judge the risk, and the released volume should be measured rather than assumed from the transformer's full capacity.

More lessons on detection and monitoring, emergency response and public communication, from every incident on the register.

Source

cbc.ca