Boiling Water reactor System
Process in The Water Reaction System
Pressurized water reactors and boiling water are two main types of generators, which the United States. uses to generate electricity. pressurized water reactors are composed of a single installation of 200 fuel elements cadded zircaloy fuel "pins." These "anchors" is immersed in a large stainless steel tank containing ordinary "light" water. Light water serves both as coolant and moderator. Light water has a greater capacity to absorb neutrons than heavy water (D2O). This implies that increasing the percentage of 235U in the core. Uranium dioxide is the source of fuel for the reactor. The pressure vessel consists of a rod through the lid, light, water pressure, and heart of the reactor. The water temperature reaches about 270 degree Celcius without boiling, due to pressure of about 13.8 to 17.2 MPa. This pressure is maintained by a pressurizer. A "light" water circulates in a closed circuit with heat exchanger. This causes the water in a heat exchanger to heat and convert to steam. This steam one or more turbine generators, is condensed and pumped back into the steam generator. Another stream of water from lakes, rivers or cold, the steam is used to condense. It is necessary to disable the reactor completely remove the cover and replace the corresponding part of the axis of fuel to refuel, which takes place every 12 to 18 months. (See figure above)
There is a potential threat, with the possibility of cracks in the pipes of the cooling system. If this happens, there would be no way to prevent the reactor from overheating. Therefore, the danger, the reactors are surrounded by double walls of the building pressure and include a number of emergency cooling systems base.
A more effective way to remove heat is to allow the water to a boil. Coolant boiling water reactors of the reactor allows the heart to a boil. The steam generated is then separated, dried and sent directly to the turbines. After crossing generators, steam is condensed and transferred to the heart of reactor. As with a pressurized water reactor, boiling water reactor fuel U-235 enriched uranium dioxide. In addition, collection of steam is also present in the upper reactor. Yet a boiling water reactor, in common with a pressurized water reactor is that it must be stopped for refueling. (See figure above)
Regarding security, the entire reactor is housed in the first housing chamber, which contains, under the great ring-shaped tunnel filled with water a little. If water or steam to escape, he falls into the tunnel and condensed. In addition, the tunnel, there are several alarm systems in place.