Darlington New Nuclear — BWRX-300 Unit 1

Current state

Notes

First grid-scale SMR construction in the West; the FOAK cost/schedule benchmark for the entire BWRX-300 order book (Poland, TVA, SK).

Milestone log

• 2025-04-04 — CNSC licence to construct granted; OPG/Ontario approved ~C$20.9bn for four units (source)
• 2026-06-24 — OPG applied to CNSC for 20-year operating licence — would be first operating SMR in a G7 country (source)
• 2026-07-01 — Unit 1 reactor building shaft excavation past 80%; reactor pressure vessel in manufacturing (source)

The milestone log is append-only: corrections are recorded as new entries, never rewrites. Full history via /api/v1/changes.

Sources

1. https://www.gevernova.com/nuclear/carbon-free-power/bwrx-300-small-modular-reactor/bwrx-300-darlington-ontario
2. https://www.opg.com/