How been possible for a last-generation nuclear power plant to remain a realistically predictable disaster as a earthquake in a seismic zone?
Emergency diesel power generators was all located at a few meters above sea level; this caused the lack of electricity and the blockage of the main cooling systems in three reactors.
Times are different, but over the next few days, at different times, the kinks of all three reactors underwent complete meltdown.
I can assure you but the biggest nuclear disaster after Chernobyl was caused by the fact that it was an emergency generator, or rather, of their poor installation.
Let’s see how it went …
Fukushima Dai-ichi, built on the coast at the ocean, was made up of six General Electric nuclear reactors managed by the Tokyo Electric Power Company (TEPCO). At the time of the earthquake alone reactors 1, 2 and 3 were active. The reactors 4, 5 and 6 were extinguished since they are required to be kept constantly cooled by storage in the outer tanks. The reactor core 4 had already been emptied and the exhausted bars had been deposited in the tube.
At the time of the earthquake, the central safety systems automatically determined the emergency shutdown (SCRAM) of the reactors 1, 2 and 3. With the reactors switched off, the electricity required to power the cooling systems of the reactors themselves is available. The reactors have cooled for some time even after their shutdown, since the core continues to produce heat as a result of the decay of the fission isotopes accumulated therein. To fill a story, it has been entrusted with a generation of diesel safety systems. Safe security systems have never been hit by the wave of tsunami.
The two reactor emergency generators number 6 were not damaged and made available, the reactor cooling system 5, whose generators had been destroyed. But in reactor number 4 there is no electricity needed to power the water pumping systems and all the secondary systems. It turned out impossible to reactivate reactor cooling systems no. 1 that are completely refrigerated for at least 24 hours, as well as the cooling systems of reactors 2 and 3 which remained completely inactive for many hours.