Darlington Nuclear Refurbishment

Rank 2021


Industry Sector: Energy

Project Type: Nuclear

Project Value: $12.8 billion

Funding Source: Public

Provincial Funding: $12.8 billion

Province: Ontario

City / Region: Clarington

Estimated End Date of Substantial Completion: 2026

The commencement of the execution phase marks the joint venture’s (JV) successful delivery of the definition phase (2012-2016) of the project, which included the construction of a full-scale reactor mock-up facility to simulate key elements of the refurbishment work and the testing of specialized tooling and to help prepare a comprehensive estimate and schedule for the project.

A $35-million reactor vault mock-up and re-tube and feeder replacement (RFR) was completed as part of the preliminary phase of the refurbishment project. Led by SNC Lavalin Nuclear (SLN) and Aecon Nuclear, the mock-up helped to train the team for feeder and fuel channel replacements to be undertaken as part of the overall refurbishment project.

The execution phase of the project will involve the replacement of main reactor components using tools and methods that were developed and tested during the project’s definition phase, carried out by the JV. Each of the four Darlington Candu reactors will be taken out of service sequentially for approximately three years to allow for the replacement of fuel channels, feeder pipes, calandria tubes and end fittings. 

The first outage took place in October of 2016, with the first reactor scheduled to be down for 40 months. The overall project is scheduled for 112 months.

In September 2020, work commenced on the refurbishment of Unit 3. Work was originally set to commence in May, however it had to be delayed as a result of the pandemic.

Project Owner: Ontario Power Generation

Engineer: Wood (consulting)

Project/Construction Manager: Aecon (Aecon Group Inc.);SNC-Lavalin (execution phase of the Retube and Feeder Replacement)

Other Key Players: GE Power; ABB; Deloitte; Kiewit; Black & McDonald; Tetra Tech; BDI Canada; Burns & McDonnell/Modus (Independant Project Oversight); Cameco (calandria tubes and annulus spacers); Alstom AA6Power & Transport Canada Inc. (turbine generator refurbishment); Hatch (engineering services); Armtec; Comtech (Project Control Consultant Services); Golder

Supplier Other: DECAST; Laker Energy (nuclear components); Nu-Tech Precision Metals (calandria tubes)

Legal: Blake, Cassels & Graydon; Torys (acting for the owner)

2020 Rank: 3

2019 Rank: 2

2018 Rank: 2

2017 Rank: 2


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