Ontario Power Generation received final investment decision approval on May 8, 2025 to build four BWRX-300 SMRs at Darlington — the first operating commercial SMR in any G7 country. Total projected cost is CAD 20.9 billion for all four units delivering up to 1,200 MW. Canada Growth Fund and Building Ontario Fund are investing CAD 3 billion in total taking minority stakes to de-risk construction. The federal government pledged $2 billion toward the project. OPG signed a deal with French company Orano for enriched uranium fuel supply diversification. Units 2–4 follow Unit 1 which broke ground in 2024.