Work underway to fix a broken turbine at the Snare Falls power plant in the NWT has exposed a list of further problems that could take up to half a year to fix, according to the NT Power Corp. (NTPC).
A bearing broke at one of the four plants on the Snare hydro system in mid-February, throwing Yellowknife into blackness and thrusting the already dehydrated community onto more diesel at an additional cost of $40,000 per day.
Now, upon further investigation, it appears the busted bearing is just the start of repairs required at Snare Falls.
“Late last week the plant was partially de-watered, below the river water level, in order to do a more thorough inspection of the turbine and that inspection revealed cracks in some of the turbine blades,” NTPC reported last Monday.
The discovery means a complete de-watering is required at the plant – something normally reserved for the summer months due to the difficulty posed by ice. Divers were required to seal the chamber over several days last week before being able to perform a complete inspection of the lower chamber to determine the extent of the damage and repairs needed.
NTPC engineers will now work with the turbine manufacturer to decide if the turbine can be repaired or if a complete overhaul is required to get the plant up and running “with a reasonable expectation of it not failing again,” according to the Power Corp.
A complete overhaul would require a four to six-month shutdown, in which case all additional fuel costs will be absorbed into a capital project spread over the life of the plant. Such an overhaul was scheduled for the summer of 2016.
If it can be fixed more simply, NTPC says repairs could be done by the end of the month.
“Fortunately, if a short-term solution is the best course of action, the parts were sent out for refurbishing with the bearing and will be back in five or six days,” according to NTPC. “This plan will increase the current repair time by about 10 days – putting the unit back in service about the end of March.”
An increased cost estimate will be revealed once the extent of the repair is known.