i learned from wikipedia that the water pumps back to reactor where it is heated again and the cycle begins again. but then i saw this diagram
As you factor out it was once the double-punch of the earthquake and tsunami that caused the problems at Fukushima. The diesel mills have been enough to control the pumps to cool the reactor but then the tsunami got here and swamped them. Shutting down the reactor after an earthquake is typical defense system. The diesel turbines had been designed to be a backup in the occasion of an earthquake. They functioned quality even after the large quake. If the quake didn't occur, but instead the planet was once just hit with the aid of the tsunami, the other planets in unaffected areas of Japan would still be operating so this implies the engineers onsite might have jerryrigged anything in order that the pumps would be powered through the country wide vigor grid even though the diesel pumps were knocked out. No longer shutting the reactors down would have resulted in much more radiation being launched as a result of the damaged structures and containment units.
I can see why you're a little confused. There are actually 3 separate loops in most reactor designs and you can see this in the diagram. The primary heat transport loop contains the water that touches and cools the fuel and this is the water that is pumped back to the reactor where it is heated again.... It is shown in the diagram in pink. The water from the primary heat transport loop passes into a steam generator which is full of water but the water in these two systems is kept separate to ensure all radioactivity stays in the primary heat transport loop and in the containment building. Basically the pipes from the primary heat transport system pass through a large tank of water and heat the water in the tank causing it to boil. The steam is then passed out of the generator, out of containment, and into the turbine. Next it goes into a heat exchanger which is similar to the steam generator except it is used to cool the water. The cooled water then passes back into containment and into the steam generator to be boiled again. Finally, the third heat transport loop moves cold water from either a lake, ocean, or cooling tower, into the turbine building where it cools the water in the secondary heat transport loop. This water is kept completely separate from the water in the secondary heat transport loop to ensure that if the secondary loop water somehow becomes contaminated, it doesn't pass into the third loop and get into the lake, ocean, or atmosphere. I hope that clears things up :)
Its clear enough. The water is heated and changed to steam in steam generators. Then the steam is used to turn the turbines to form energy. The steam is then condensed using cold water. The condensed steam or water is then 'pumped back to the steam generator' to create steam and the cycle continues. Need any more help ? feel free to mail me.
