Northwest Territories Power Corporation's Snare Falls generating plant repaired and back in service

The turbine at the Northwest Territories Power Corporation's (NTPC) Snare Falls hydroelectric plant is back in service and generating power for Yellowknife and North Slave as of 4 p.m. Monday, March 16, 2015.

"We were able to bring this unit back online a few days ahead of schedule thanks to the crews' and experts' commitment and dedication to getting this issue resolved safely and quickly," said Emanuel DaRosa, President and CEO of NTPC. "I'd also like to thank our customers for their conservation efforts during this time - it helped minimize the amount of diesel used."

The turbine failed on February 15 and actions were immediately taken to minimize lost water. Operations shifted to the most water efficient strategy - limiting the use of hydro to minimize diversion around the Snare Falls plant while building up the reservoir for later use.

The investigation pointed to a damaged bearing and at that time all spare bearings were shipped to a machine shop in Vancouver for refurbishment - parts arrived back at Snare on Saturday, March 7. These bearings have a shelf life of approximately three to five years, as without use, some of the materials can separate making them unusable.

NTPC brought in an expert to determine the extent of the repair and a certified contractor to build scaffolding to ensure a safe work environment while crew dismantled the turbine.

Two weeks ago the plant was partially de-watered to do a thorough inspection of the turbine. That inspection revealed cracks in some of the turbine blades. This prompted a complete de-watering which is rarely done during the winter months due to the difficulty that ice build-up adds to the process, however in this case it was unavoidable. This process identified an additional bearing in the lower chamber as requiring replacement.

To bring the turbine unit back into service the blades were repaired, both upper and lower bearings were replaced, and the unit was re-aligned and re-watered. While the unit is functioning normally at this time, it is still scheduled for a complete overhaul later this spring when demand for electricity is lower and the need for additional diesel generation is decreased.

Current estimate of repairs is $505,000 and additional fuel is estimated at $1.16 million. NTPC is working closely with our Shareholder - the GNWT -- to minimize the impact of this event on customers and cost of living in the Territories.