Ontario announces nearly $66 million in Darlington reactor contracts

Ontario announced Nov. 9, 2026, that Gillam Construction Group and Mansteel Rebar had been awarded contracts valued by the province at nearly $66 million for an administration building and reinforcing steel at the Darlington small modular reactor project in Clarington. The province gives conflicting values for Mansteel’s contract.

The work is part of Ontario Power Generation’s Darlington New Nuclear Project, which calls for four small modular reactors at the Darlington nuclear site. The province approved construction of the first reactor in 2025 and says the four units will have a combined generating capacity of 1,200 megawatts once complete.

Gillam Construction Group, based in Carp, will receive nearly $35 million to construct the project’s administration building, according to the Ministry of Energy and Mines. The ministry says the contract will create 100 jobs.

Pembroke-based Mansteel Rebar will receive $31 million for reinforcing steel work, according to the ministry. Mansteel’s work involves fabricating, supplying and installing reinforcing steel for five of the plant’s core buildings. The province says that work will support 100 jobs and add another 20 during construction.

Renfrew–Nipissing–Pembroke MPP Billy Denault called it a $17-million contract in the province’s release, rather than the $31 million listed by the ministry.

Mansteel general manager Allen Piddington said the company already has workers on site and sources all its reinforcing steel from Canadian steel mills.

The two companies join more than 100 Canadian firms that have signed agreements with Ontario Power Generation for the project, the ministry said. Companies in the Greater Toronto and Hamilton Area received 14 project contracts the previous week.

Ontario says 80 per cent of project spending is to go to Ontario companies. Ontario is investing $1 billion in the project through the Building Ontario Fund, and the federal government is investing $2 billion through the Canada Growth Fund.