Plans to bring the Taltson hydroelectric dam back online next week are being postponed after "serious corrosion" was discovered in the plant's 60-year-old surge tank and the unit could require "major remediation work," says the NWT Power Corporation.
"The surge tank is an essential part of the Taltson plant and is between the main dam and the powerhouse," NTPC stated on Aug. 8. "It is used to stabilize the water going into the plant. If the plant shuts down due to an unplanned event, the water will 'surge' into the tank until the headgate at the main dam can close.
"The length of the delay is not known at this time but NTPC acknowledges that it is possible that major remediation work on the 60-year-old surge tank will be required."
Corrosion in the surge tank was known to NTPC for several years, the public notice adds, but a third-party inspection concluded the corrosion was significantly worse than first believed.
Remediating the tank was not in the original work plan for the Taltson hydroelectric overhaul, which was supposed to wrap up its finishing touches during a three-week shutdown following a two-year overhaul.
Customers in Hay River, K'atl'odeeche First Nation and Enterprise who normally rely on the Taltson dam for their power have been switched over to diesel generators, which have also been plagued with problems. Shortly after the diesel generation went online, a major equipment failure led to a total power outage across the grid on July 30. The system was down for much of the day as emergency equipment was brought in. Two days later, another major power outage hit the region as the emergency equipment also malfunctioned. The South Slave was in the midst of a heat wave at the time, with Environment Canada warning temperatures could rise as high as 30 C.
NNSL Media has reached out to NTPC for more information.
