OPG installs first prefabricated basemat at Darlington

Ontario Power Generation installed the first prefabricated basemat module at the Darlington New Nuclear Project this month, lowering the completed unit into place with a heavy-lift crane rather than performing a continuous on-site concrete pour.

The basemat was built off-site and transported to the Darlington site in Ontario, shortening the period of intensive foundation work compared with a multi-day continuous pour and large on-site rebar assembly.

The prefabricated module replaces the traditional method of pouring continuous concrete and assembling extensive rebar lattices across several acres. Project engineers expect the approach to reduce the scale and duration of foundation work for small modular reactor facilities.

GE Vernova leads the Darlington effort alongside Ontario Power Generation. Other participants listed in project materials include BWX Technologies, which will engineer and manufacture the reactor pressure vessel, Doosan Enerbility, Samsung C&T and Hitachi.

Project documents describe the work as part of a plan to develop a repeatable reactor design that could be exported and built at other sites. Building modules off-site allows components to be fabricated under controlled conditions and then transported to the plant for assembly.

At Darlington, the heavy-lift crane lowered the basemat module into position, avoiding the extended continuous concrete pours that have historically been used for large reactor foundations.

Industry observers and financial analysts tracking nuclear supply chains and related investment vehicles are monitoring the installation. Indexes such as the VettaFi Nuclear Renaissance Index (NUKZX) and the Range Nuclear Renaissance ETF (NUKZ) include companies that supply equipment and services for SMR projects.

Supporters of small modular reactors say the smaller physical footprint and standardized modules can shorten construction time and reduce capital intensity compared with large traditional reactors that have experienced delays and cost overruns.

Governments and industry groups in G7 countries have promoted SMRs as a source of carbon-free baseload power and have set targets to expand nuclear capacity by 2050. The Darlington basemat installation provides a data point on modular construction for a commercial-scale SMR project in a G7 country.