Assignment A: Account
According to the online information site HowStuffWorks, the whole nuclear disaster in Japan in 2011 was started because of an earthquake. As a result of the earthquake the four reactors was automatically shut down. The plants then stopped producing power, and the cooling pumps were started. The cooling pumps should help cooling the water. The cooling pumps needed electricity to work, but because of the automatically shut down, the cooling pumps couldn’t use the first source of electricity. The plants could then get electricity from the power grid, but that shut down as well. So it started using the power from the diesel generator. The diesel generator has been tested many times, and also in this case it worked very well. But then the tsunami hit the power plant few moments later. The diesel generators were therefor under water, and couldn’t produce power anymore. It was time for the last source of electricity, which were the batteries. The batteries worked well, but they were produces to last for only few hours. The operators tried to send new generator to the power plant, but it was to late. The batteries ran out, and the cooling pumps failed. Without any cooling system in the reactor, the water began boiling. And as the water was boiling away, something called metal tubes was overheated and cracked. The cracks allowed water to enter in the pipes to the fuel pellets. This started something called thermolysis, where the generator began generating hydrogen gas, which is a highly explosive gas. The pressure from the hydrogen gas was build up, and needed to be vented out. The pressure needed to be vented out so quickly, that it exploded in the reactor. The same happened in the other reactors. The explosions damaged the concrete and steel buildings around the pressure vessels.
Assignment B: An eyewitness report.
It was Friday March 11th and I was in a hotel in Fokushima in Japan....