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March 11th, an earthquake and a tsunami destroyed large parts of of Japans sealine and left 8000 dead and 12000 missing, still not found. The disaster shook Fukushima I, a nuclear power plant which left it unstable. The reactors were "shut down" immediately, but nuclear reactors continue to generate large amount of excess heat even after the primary reaction is stopped. That's why large amounts of cooling water are needed on the reactors over a number of days to bring it down to a stable temperature.
However, in Fukushima, the large tsunami (caused by the earthquake) destroyed power and backup power generators for the cooling water, so temperature in the reactors continued to rise. This caused pressure to increase and steam was vented most likely to relieve this pressure. The steam was radioactive but unlikely at dangerous levels. The explosions were most likely caused by steam being vented into the space between the main reactor and the outer wall, and the steam combusting in a "hydrogen explosion". These explosions are unlikely to have breached the inner reactor, and therefore the most dangerous radioactive material is not being released to the atmosphere.
Cooling water was restored (though the situation seems to change daily) but if the plant was left unattended, nuclear fuel rods in the main reactor would melt (they have only partly melted so far). Still, the inner reactor walls should hold (this is what they are designed for). In a worst case scenario, these walls break or crack and radioactive iodine and cesium (among other things) is released into the atmosphere. These are particularly dangerous and will continue to pose a threat to people's health for many years. Relatively small amounts may have already been released into the atmosphere and nearby ocean though I am not sure exactly how.
The worst case scenario is still fairly unlikely, and it would be much less deadly than the Chernobyl disaster, which was a particular kind of incident only possible with the Russian reactor design. A worst case disaster at Fukushima would not effect countries like the USA, and the deaths (if any) would pale in comparison to those killed in the original earthquake and tsunami.
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As of May 24, TEPCO, the owner of the plant, has acknowledged that there have been three meltdowns. Reactor 1 has been described as having been completely melted down, with its fuel in a single lump at the bottom of the pressure vessel. Reactors 2 and 3 are described as having gone through partial meltdowns. There is also discussion about one or more of the reactors having been breached.
There is a link below to the May 24 entry for a timeline in Wikipedia.
What else can I help you with?
Is reactor number 3 really in critical at Fukushima?
As of the most recent information available, reactor number 3 at the Fukushima Daiichi nuclear power plant is not in a critical state. The situation at the plant is being closely monitored, and any developments regarding reactor number 3 and the overall safety of the plant will be reported by relevant authorities.
What is their relationship to the Fukushima Nuclear Power plant?
The Fukushima Nuclear Power plant is a Japanese nuclear power plant in which the reactor meltdown occurred after the tsunami and earthquake in 2011. It is a site of paramount historical global significance to the nuclear energy and safety sector.
When did the Fukushima nuclear accident happen?
It happened on March 11th, 2011 at 2:46 local time.
Where did fukushima happen?
Fukushima is not an event that happened, it is a place, a prefecture, or district, in Japan. There are two Fukushima nuclear power plants. The plant where the accident took place, Fukushima Daiichi, is located in Okuma, Fukushima, Japan.
How did the Fukushima nuclear power plant work?
The Fukushima nuclear power plant used nuclear fission to generate heat, which was then used to produce steam that drove turbines to generate electricity. However, a tsunami in 2011 caused a series of failures that led to overheating and meltdowns of the reactor cores, resulting in a nuclear accident.
Is reactor number 3 really in critical at Fukushima?
As of the most recent information available, reactor number 3 at the Fukushima Daiichi nuclear power plant is not in a critical state. The situation at the plant is being closely monitored, and any developments regarding reactor number 3 and the overall safety of the plant will be reported by relevant authorities.
What is their relationship to the Fukushima Nuclear Power plant?
The Fukushima Nuclear Power plant is a Japanese nuclear power plant in which the reactor meltdown occurred after the tsunami and earthquake in 2011. It is a site of paramount historical global significance to the nuclear energy and safety sector.
What is the Fukushima Power Plant?
There are two Fukushima power plants. Both are in the prefecture of Fukushima, Japan. The plant you have in mind is probably the Fukushima Daiichi Nuclear Power Plant, which experienced a series of meltdowns after an earthquake and tsunami of March 11, 2011. The other is the Fukushima Daini Nuclear Power Plant.
When did the Fukushima nuclear accident happen?
It happened on March 11th, 2011 at 2:46 local time.
Where did fukushima happen?
Fukushima is not an event that happened, it is a place, a prefecture, or district, in Japan. There are two Fukushima nuclear power plants. The plant where the accident took place, Fukushima Daiichi, is located in Okuma, Fukushima, Japan.
How did the Fukushima nuclear power plant work?
The Fukushima nuclear power plant used nuclear fission to generate heat, which was then used to produce steam that drove turbines to generate electricity. However, a tsunami in 2011 caused a series of failures that led to overheating and meltdowns of the reactor cores, resulting in a nuclear accident.
Where is the Fukushima power plant?
There are two Fukushima nuclear power plants, both of which are in the Fukushima district on the east coast. Fukushima Daiichi, where the meltdowns happened, is at a town called Okuma. Fukushima Daini, is at a town called Naraha.
What is the function of a nuclear reactor of a nuclear plant?
simply, the nuclear reactor is the source of heat (or steam) for the nuclear power plant.
How old is Fukushima Daiichi nuclear power plant?
Construction for the Fukushima Daiichi plant began on July 25, 1967. The first reactor to go on line was Unit 1, commissioned on March 26, 1971. At the time of the meltdowns, the plant had been in operation for almost 40 years.
Where is Japans' nuclear plant that has a leak?
Fukushima
What is the difference between nuclear reactor and nuclearpower plant?
a nuclear reactor converts binding energy into heat. a nuclear power plant uses a nuclear reactor to generate electricity.
How many reactors have exploded at the Fukushima Daiishi nuclear power plant?
I think four of the six on site, but they have not all had the same problems. The explosions were actually in the reactor buildings, not inside the reactor pressure vessels, and these explosions were due to hydrogen accumulating and forming an explosive mixture with air
