Wiki · SMR · Canada and United States
BWRX-300
Under constructionGE-Hitachi's boiling water SMR, derived from the ABWR, under construction at Darlington since 2025.
The BWRX-300 is a 300 MWe natural-circulation BWR that simplifies the ABWR: no recirculation pumps, isolation valves integrated into the vessel and passive cooling by isolation condensers for seven days. It is the only boiling water SMR under construction.
Ontario Power Generation started building the first unit at Darlington in May 2025, with four planned by 2035. Tennessee Valley Authority, in the United States, and Poland follow.
Quick facts
| Power | ≈ 300 MWe |
|---|---|
| Type | natural-circulation BWR |
| Construction | Darlington, Canada, since May 2025 |
| First operation | 2029 to 2030 |