TIVERTON, Ont. -- Bruce Power has synchronized its Unit 2 to Ontario's electricity grid, producing power from the unit for the first time in 17 years.

The company says final commissioning activities will now be carried out, including safety-system shutdown testing.

Plans to connect the unit to the grid were delayed in May due to damage to non-nuclear equipment at the site.

The utility's Unit 1 was reconnected in September.

Bruce Power says once both units are at full strength, they'll generate enough electricity to power cities the size of Ottawa and London, Ont., combined.

The return to service of Units 1 and 2 brings the site back to its eight-unit capacity, doubling the number of operational units from 10 years ago when the company began a revitalization program.

The company calls it a "major milestone."

"This gets us one step closer to the finish line and for the first time in nearly two decades, we're in the midst of returning the site to its full operational capacity," the company's president and CEO, Duncan Hawthorne, said in a statement.

Bruce Power has two units containing four Candu reactors each at its site in Tiverton, Ont., on the shores of Lake Huron.