核电站3（Nuclear power plant 3）.docVIP

核电站3（Nuclear power plant 3） The reactor at the Fukushima nuclear power plant belongs to the Boiling Water Reactors (abbreviated as BWR). The boiling water reactor is similar to our usual steam pressure cooker. The nuclear fuel heats the water, which vaporizes when it boils, and then the steam drives the turbine to produce electricity, and then the steam cools and goes back to the liquid, and then sends the water back to the nuclear fuel to heat it up. The temperature in a steam pressure cooker is usually about 250 degrees centigrade. The aforementioned nuclear fuel is uranium oxide. Uranium oxide is a ceramic with a melting point of 3000 degrees centigrade. The fuel is made into small columns (imagine, like a small column of Lego size). These small columns are placed in a long barrel made of zirconium tin alloy (melting point 2200 degrees Celsius) and sealed. This is a fuel rod (fuel, rod). The fuel rods are then put together to form a larger unit, and then the fuel cells are put into the reactor. All of these are the contents of a nuclear reactor core (core). The zirconium tin alloy shell is the first layer shield used to isolate radioactive nuclear fuel from the world. Then the core is put into the pressure cabin, which is the metaphor of the steam pressure cooker we mentioned earlier. The pressure cabin is the second layer shield. Its a sturdy, large pot designed to hold a core that can reach hundreds of degrees celsius. Before the core cooling measures are resumed, the pressure cabin plays a certain role in protection. All of these hardware - - pressure tanks, pipes, pumps - of a nuclear reactor, The cooling water is then encapsulated into the third layer shield. The third shield is a fully sealed, very thick sphere made of the strongest steel and concrete. The design, construction, and testing of the third - layer shield is for one purpose: wrapped in the core when it is completely molten. To achieve this, a huge, massive concrete bowl was cast underneath the p