You might already know that we are in fear of radiation from nuclear plants in Fukushima.
People watched lots of news about the situation of plants, but it is not easy to understand how the system of plants are working. Even people in Japan don't actually grasp the image of it much.
So, I collected a lot of information, and try to tell you briefly.
When the first huge earthquake hit northern Japan, two plants were working in Fukushima.
Plant No.1 had 6 active nuclear facilities and Plant No.2 had 4 active facilities.
Those plants were forced to stop the system automatically by the huge quake.
I add a necessary information to help you understand the whole image of the explanation here.
Nuclear fuels generate over 2,700℃ Celsius heat in a 5-layer container and cannot stop its reaction suddenly. So, it takes a lot of time to make the fuels inactive.
Water is continuously put in the container and it is cooled down. Once the water doesn't cover the container, the container itself is melted down and huge amount of radiation is out as a result.
So, two plants stopped working but the nuclear fuels still were active and generates lots of heat.
In a regular situation, the container in which nuclear fuels have a reaction is cooled down by lots of water and it is regulated automatically with electricity.
Substations were all fallen down and stopped the supply of the electricity to the plants in that area because of the huge quake.
Although cadmium and boronic acid which inactivate neutrons were stored, the engineers couldn't drop those chemical elements in the containers because of the loss of electricity.
However, the plants still had two backups for this situation.
(1) The main backup was two controllers called diesel generators.
People considered 7m tsunamis when they built the plants, but it's estimated that 14m tsunami hit the plants. Therefore, the electrical system of two diesel generators were lost the control by water.
(2) The other backup was a storage battery. However, the electricity worked only for the first 7 hours.
Engineers at TEPCO had put water to the container by a large pump after the storage battery run out,
However, the pump got broken and the engineers decided to put seawater into the container which means to wreck the whole facilities.
Also, you know that there were explosions at the nuclear plants.
The explosions were not directly caused from nuclear fuels. Water is continuously put in the container, and water react with Zirconium of container and generates hydrogen.
The generated hydrogen is oxidated and get back to oxygen in a situation which can use electricity.
However, the electricity is off in the facility and they cannot generate that reaction.
Therefore, they let hydrogen out. As a result, the hydrogen accumulated outside of the container and exploded.
So, the officials say those explosions don't affect the container and nuclear fuels.
I wrote a lot to explain the system of nuclear plants and what they have hundled with.
Although there were some problems in TEPCO's estimation, all people in Japan really appreciate their effort now. Workers there have done their best with the fear of radiation exposure.
My father had worked for TEPCO for 40 years and he retired last year.
I called him last night and he said he is also really worried about the workers there. He is not sure, but some of them might be his coworkers.
I really wish the situation doesn't get worse than now, and nobody is harmed by this.