Canada’s Ontario Power Generation (OPG) on 19 February was permitted by the provincial government to go ahead with the refurbishment of unit 3 at the Darlington nuclear station, an 878MWe Candu pressurised water reactor.
The Ontario ministry of energy said the refurbishment would ensure that reliable, nuclear energy “continues to be the backbone" of the generation fleet. All four units at Darlington are being refurbished as part of a phased CAD12.8bn ($9bn) project scheduled for completion by 2026. Darlington 3 will be the second unit to undergo refurbishment. Work on unit 2 is 50% complete. The plans require refurbishment of Darlington 2 to be completed before work starts on Darlington 3 to benefit from “lessons learned”.
Refurbishment of Darlington 2 formally began in October 2016 after six years of planning and is expected to take 40 months. The project remains on time and budget, OPG said. To date, all 960 end fittings from the reactor's fuel channels have been removed from core, and work has started to remove the pressure tubes using remotely controlled automated retooling platforms. Removal and replacement of the reactor's 480 calandria tubes, 480 pressure tubes and 960 feeder pipes are the most significant project tasks.
Work on Darlington 3 is scheduled to begin in February 2020, on Darlington 1 in July 2021 and Darlington 4 in January 2023. The project will enable the 3512MWe plant to continue operating until 2055. Each unit is being taken out of service for three years to allow the work to be carried out. Between 2016 and 2033, ten Candu units will be refurbished – four at Darlington and six at Bruce NPP. Work has already completed on two of Bruce’s eight units. The Pickering nuclear plant will continue to operate until 2024 to provide baseload electricity during the Darlington and Bruce refurbishments.
Photo: Darlington nuclear plant (Credit: OPG)