The info is gathered from Wikipedia, Swedish, Hungarian and English websites. Pictures are pulled from the web.
Japan has 17 nuclear power plants with 55 active reactors. Ten companies own 52 of the reactors within the Federation of Electric Power Companies of Japan (FEPC) The other 3 reactor are private. Two reactors are being build and there are plans to build another 11 reactors.
So what has happened until know and what is the history behind the damaged power plants?
Altogether 11 reactors have stopped working after the earthquake, from these 3 nuclear power plants was having problems with the backup cooling system.
Fukushima power plants is situated 250 km away from Tokyo, it consists of two power plants, Fukushima 1 and Fukushima 2.
Fukushima 1 has 6 reactors, built between 1971 and 1979. Reactor 4 and 6 where shut down during the earthquake due to maintainance. Fukushima 2 is around ten km from Fukushima 1, it has 4 reactors and was built between 1982 and 1987.
Fukushimas reactor 1 and 3 most likely experienced partial meltdown. On Saturday, a huge explosion blew apart the building housing reactor 1, where technicians had been venting steam to cool the reactor. Sea water was injected into the other reactor in an attempt to cool it.
Update (March 14): Fukushima 1 reactor 3 also exploded due to Hydrogen gas formation this monday morning, Japan claim, little risk of radioactivity, ( I cant help but wonder if this is the entire truth) reactor 2 is reported having problems with the cooling, for me it looks like they have gotten their own Tjernobyl by now.
Update (march 15)
A third explosion took place in Fukusima 1, this time it was reactor 2, officials says there might be a risk for massive leakage, the blast may have damaged the vessel that holds reactor 2.
The radiation reading at 0831 local time (2331 GMT) climbed to 8,217 microsieverts an hour from 1,941 about 40 minutes earlier, Tepco said. The annual legal limit is 1,000 microsieverts. These values are a risk for human health.
Japan’s PM says there is a ‘very high’ risk of further radiation leaks
A fire which briefly broke out at the plant’s reactor 4 on Tuesday is also believed to have led to radioactive leaks.
Higher radiation levels were recorded on Tuesday south of Fukushima, Kyodo news agency reported.
Levels in Tokyo were higher than normal, but officials said there were no harmful levels. According to NHK world TV stream they say they can find small amounts of both Cesium and iodine particles in Tokyo.
There is also talk about Fukushima 1 and 2 stores used up radioactive material under the plants.
Picture: Fukushima reactor 1.
Picture: Fukushima before the accident.
Tokai was Japan’s first nuclear power plant. It was built in the early 1960s and generated power from 1966 until it was decommissioned in 1998. A second nuclear plant, was built at the site in the 1970s.
Unit 1 was thought be the first nuclear reactor to be decommissioned in Japan, the reactor stopped working in 1998 and was planned to be completely removed this year.
The number 2 reactor was one of eleven nuclear reactors to be shut down automatically. It was reported on 14 March that a cooling system pump for the number 2 reactor had stopped working. Japan Atomic Power Company stated that there was a second operational pump and cooling was working, but that two of three diesel generators used to power the cooling system were out of order.
Excessive radiation levels were recorded in Onagawa, although the shutdown was functioning properly. They believe the high measurements are findings from Fukushima power plant.
The Onagawa Nuclear Power Plant was the most quickly constructed nuclear power plant in the world. The Onagawa-3 unit was the most modern reactor in all of Japan at the time of its construction. The plant conforms fully to a set of international environmental management standards. All the reactors were constructed by Toshiba.
Onagawa has three units. Since November 11, 2006 unit 1 has been shut down due to the result of a test. Unit 2 also had problems. In may 2006 it was confirmed that a pipe was leaking due to debris damage. In june 7, 2006 it had difficulties with pressure control prompted further inspections and in july 7, 2006 it was determined that the plant’s performance was not satisfactory.
Reactor nr 3 in Onagawa was in July 7, 2006 due to pipe integrity concerns shut down, in November 25, 2006 following repairs the reactor was restarted. March 11, 2011 due to the earthquake damaged the turbines after a fire broke out and was shut down.
Picture of Onagawa.
Update on Japan
The past days have been largely a chaos of same, reactor 1,2 or 3 or 4 is either burning or leaking, the radiation levels are undulating, things are far away from solved.
Latest is that they managed to get electricity to the power plant, hopefully, this might solve a huge problem. To what extent the failsafe containment vessels has been damaged is something no one can answer, and what consequences can happen?
This is taken from CNN.
When the earthquake struck and the Fukushima Daiichi reactors shut down, the water pumps lost power. Emergency diesel generators began to power the pumps. However, the tsunami that soon followed damaged the diesel generators. The pumps then operated on emergency battery power, which lasted for 8 hours before being exhausted.
Reactor No. 4 is one of the three reactors shut down for inspection when the earthquake and tsunami hit. However, nuclear fuel was still present in the building in the storage pond.
These fuel rods are not within the concrete and steel containment system that houses the reactor vessel. CNN contributors warn that a fire in the spent fuel storage pond could spread radioactive material directly into the surrounding environment.
The International Atomic Energy Agency (IAEA) developed the International Nuclear and Radiological Event Scale to identify the severity of incidents involving nuclear energy.
Chernobyl was a level 7 accident, the highest level, denoting a “major accident.”
Three Mile Island was classified a category 5, which is an “accident with wider consequences.”
The IAEA is not yet rating the incident in Japan on the INES scale.
Latest update: 12 April, Fukushima is classified as a 7. It took the authorities some while to come forward with it. Even though its a 7, it differs in severity from Tjernobyl as for now,