BWR
Boiling Water Reactor
Boiling water reactor (BWR) uses light water as both moderator and coolant, boiling directly in the core to produce steam for turbines.
BWRs operate at pressures around 7 MPa and temperatures up to 290°C, using slightly enriched uranium (3-5% U-235) in zircaloy-clad fuel assemblies. Steam separators and dryers in the vessel ensure turbine quality. Over 50 BWRs operate worldwide, mainly in the US and Japan, with designs like GE's ABWR and ESBWR featuring passive safety.
Why it matters now
BWR-derived SMRs like GE Hitachi's BWRX-300 are advancing NRC licensing in 2025, targeting data center PPAs amid rising power demand. Legacy BWR fleet extensions support grid reliability.