Back مفاعل الماء المغلي Arabic ফুটন্ত জল চুল্লী Bengali/Bangla Reactor d'aigua bullent Catalan Varný reaktor Czech Siedewasserreaktor German Bolakva reaktoro EO Reactor de agua en ebullición Spanish واکنشگاه آب جوشان FA Kiehutusvesireaktori Finnish Réacteur à eau bouillante French
A boiling water reactor (BWR) is a type of nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating nuclear reactor after the pressurized water reactor (PWR).
BWR are thermal neutron reactors, where water is thus used both as a coolant and as a moderator, slowing down neutrons. As opposed to PWR, there is no separation between the reactor pressure vessel (RPV) and the steam turbine in BWR. Water is allowed to vaporize directly inside of the reactor core (at a pressure of approximately 70 bars) before being directed to the turbine which drives the electric generator. Immediately after the turbine, a heat exchanger called a condenser brings the outgoing fluid back into liquid form before it is sent back into the reactor. The cold side of the condenser is made up of the plant's secondary coolant cycle which is fed by the power plant's cold source (generally the sea or a river, more rarely air).
The BWR was developed by the Argonne National Laboratory and General Electric (GE) in the mid-1950s. The main present manufacturer is GE Hitachi Nuclear Energy, which specializes in the design and construction of this type of reactor.