Technology Type

The Boiling Water Reactor (BWR) is the second most common nuclear reactor type worldwide, representing about 22% of operating reactors. It features a single-circuit design where water boils directly inside the reactor core at about 285°C and 75 times atmospheric pressure. The steam-water mixture rises through the core, passes through moisture separators, and flows directly to the turbines to generate electricity. BWRs are distinguished by their ability to operate in load-following mode through coolant flow adjustment using recirculation pumps and control rods. The design is simpler than PWRs due to its single circuit, but requires additional shielding and radiological protection during maintenance due to the steam's direct contact with the reactor core.