POINT TUPPER: Nova Scotia Power (NSP) is in the midst of a major renovation to its Point Tupper Generating Station, and one well-known structure at the site is on its way down.
On August 26, NSP announced that it started the process of dismantling its 91-metre stack, and it will come down the way it was constructed, one section at a time.
“It’s a fairly slow process, starting at the top, as we remove the stack layer by layer,” said Steve Kyle, Plant Manager at the generating station. “But the end result will be a dramatic one. It will change the landscape, that’s for sure.”
Hamon Custodis Cottrell Canada, specialists in power stack removal, will conduct the work on the 50-year-old stack, which is expected to take up to three months to complete. Scaffolding will be attached to the stack, made of reinforced concrete, and workers will lower the debris through the stack chimney as it’s removed.
NSP communications manager Patti Lewis explained this keeps dust to a minimum.
“We’re removing the outer portion of the stack and because of the inner liner [which has already been removed], it would not have been in contact with flue gas,” Lewis explained.
All debris will be disposed according to government regulations. Explosives will not be used, and noise and dust are expected to be minimal, NSP said.
“We have a very experienced contractor who is very aligned with Nova Scotia Power’s ‘safety-first’ approach,” said Kyle.
The power stack has been out of service since Point Tupper’s Unit #1 generator was decommissioned in 1987. The dismantling process is a two-phased project, as in 2018, the inner lining of the power stack was removed.
A second, 101-metre power stack remains in service, serving Unit #2. The Point Tupper Generating Station produces 154 megawatts of electricity.
The Point Tupper plant began operations in 1969 when the site was selected by government to supply steam for the processes of an adjacent facility that was built to produce heavy water for the nuclear power industry. Unit #2, which was added in 1976, originally ran on imported oil and was converted in 1987 to use coal that was mined locally at the time. Once that conversion was complete, Unit #1 was decommissioned.
Although coal dust was not a factor because Unit #1 used oil for fuel and was not converted to coal like Unit #2, Lewis said there is lead paint in the upper portion of the stack.
“The contractor is trained to safely manage its removal and will ensure the disposal occurs as per regulatory requirements,” Lewis noted. “Testing was completed to ensure there were no other contaminants.”
Lewis also explained that the coal pier and transport infrastructure in Point Tupper will remain.
“They were constructed during the coal conversion process for Unit #2 which is still in use,” she said. “Unit #1 was oil fired. The coal infrastructure is not associated with Unit #1.”
With construction expected to conclude before the snow starts, Lewis said NSP is relying on stations like Point Tupper during this transition period.
Because renewable electricity is largely weather dependent – wind for wind power and rain or snow melt for hydroelectricity – Lewis said the amount of renewable electricity being generated varies from day-to-day, and sometimes hour-to-hour.
“Point Tupper plays a vital role in providing baseload generation and filling in the gaps when renewable generation is low,” she stated. “Point Tupper and the neighbouring Port Hawkesbury Biomass facility, provide necessary and dependable backup to renewable energy, ensuring electricity is there when people need it.”
Along with the stack dismantling, Lewis added that the company just completed a $14.5 million refurbishment of the plant’s turbine and generator.