The Boiling Water Reactor (BWR) Power Plant and its Advantages and Disadvantages
- The arrangement of a boiling water reactor power plant is shown in Figure. It uses enriched uranium as fuel and water is used both as coolant and moderator.
- These reactors do not require a heat exchanger as needed in case of pressurized water reactors since the water is directly converted in a saturated steam at about 285°C at 70 bar pressure.
- For these reason, this system is also called as direct cycle boiling water reactor power plant. The feed water circulated in the reactor is converted into saturated steam by transfer of energy released by fission in the reactor core.
- This steam is supplied to steam turbine in a conventional power plant working on the cycle. The mechanical power developed by the turbine is converted into electric energy by the generator.
- The exhaust of steam from turbine is condensed in the condenser. The condensate is returned to reactor as feed water by the feed water pump.
- In India the Tarapur atomic power plant works on BWR principle.
- It eliminates the use of heat exchanger, pressuriser, circulating pump and piping. Therefore system is simple, cheap and efficiency is high.
- Use of low pressure reactor further reduces the cost of plant.
Disadvantages of Boiling Water Reactor :
- It has the possibility of radioactive contamination of steam turbine.
- It cannot meet the sudden changes in load on the plant.
- System requires extensive safety devices against radioactive radiations which are costly.