OPG said the potential four-month delay to the return to service of Unit 2 is a result of delays related to fabrication and installation of feeder tube components. The fabrication delays resulted in upper, middle and lower feeders being installed at the same time, creating logistical and physical challenges with overlapping work.
The impact of the Unit 2 fabrication delays has been fully resolved and will not affect future units, OPG said.
“The refurbishment of Unit 2 remains on budget and the overall budget and schedule for the 10-year refurbishment project also remains on track,” it said.
OPG said it has completed 85% of the Unit 2 construction work. The installation of fuel channels, upper and middle feeders, and the installation of reactivity safety system mechanisms were recently completed. Thirty-three of 58 major plant systems have also been returned to service.
The refurbishment of Unit 3 is scheduled to begin in the first quarter of 2020. Design and engineering are more than 90% complete and are on track for full completion by the end of 2019.
Darlington-2 is the first of the Darlington station’s four Candu units to undergo refurbishment in a project that will enable the station to continue operations until 2055. All four units are to be refurbished in a phased CAD 12.8bn ($9.7bn, €8.4bn) project which is scheduled for completion by 2026.
Each of the four units will be taken out of service for three years for work to be carried out.
Ten Candu units in Canada are being refurbished between 2016 and 2033 – four at Darlington and six at Bruce. The Pickering nuclear station will continue to operate until 2024 to provide baseload electricity during the Darlington and Bruce refurbishments.