Why and how did the nuclear reactors in japan fukushima partially meltdown?

Luther

i need an answer quick! Why and how did the nuclear reactors introduce Japan (Fukushima) partially meltdown? divert include full and precise widen. Information forth a website please as i have to write a bibliography regarding each reply. I backside't remember hugely but our don vocalized something involving the tsunami and earthquake (obviously), cool air, a fuel pool, leaks, fuel rods had to do with this. thanks!



Hartford

In nuclear reactors, the "fuel" is a fissionable substance such as uranium235. Typically uranium is enriched to about 3% uranium235 & then used in the form of UO2 pellets. These enriched uranium pellets are encased in zirconium or stainless steel tubes. Rods composed of materials such as cadmium or boron control the fission process by absorbing neutrons. These control rods regualte the flux of neutrons to keep the reaction chain self-sustaining while preventing the reactor core from overheating. The reactor is started by a neutron-emitting source; it is stopped by inserting the control rods more deeply into the reactor core, the site of the fission. The reactor core also contains a moderator which acts to slow down the neutrons so that thay can be captured more readily by the fuel. A cooling liquid circulates through the reactor core to carry off the heat generated by the nuclear fission. Most of the time the reactor core which contains the control rods, fuel rods & circulating cooling fluid cannot reach supercritical levels and explode which the violence of an atomic bomb (full meltdown) because the concentration of uranium 235 is too low. However if the core overheats sufficient damage might be done to release radioactive materials into the environment (partial meltdown) which is what is happening in the case of Japan. The tsunami & earthquake has damaged the electrical connections in the reactor, the primary coolant which passes through the core is in low levels in the reactor core. Hence the fuel rods faces a risk of overheating & burning their way through the steel pressure vessel reactor core they are confined in. That is why Japan is trying hard now to pour seawater into the plant to keep the fuel rods inside the reactor core from being exposed to the air where they could reach critical stage and go into full meltdown.



Rosalie

Here is an informative article describing the situation:http://bravenewclimate. com/2011/03/13/fu…And here is where you find current, factual status information:http://www. iaea. org/newscenter/news/tsun…And here is a chart that helps make sense of the numbers:http://www. xkcd. com/radiation/Polly, great answer, but one point. The seawater has now been replaced with freshwater, except for the storage pools.



Parkton

Made in America. Look up GE BWE reactors and their design flaw on CNN or google.