Events on the emergency NPP Fukushima-1 in Japan continue to evolve dramatic scenario

The media all over the world almost every hour during the day passed reports of new emergency at the plant. The most disturbing — as a result of a thermal explosion in the second power unit is damaged primary reactor containment. And this news confirms experts from the International Atomic Energy Agency.
Also, according to the IAEA in the area of Fukushima radiation levels rose to dangerous levels. The situation is so vague, that while the experts can not calculate any immediate or long-term consequences for the world's nuclear power industry.
Helicopters from the U.S. aircraft carrier "Ronald Reagan", delivering humanitarian aid to the victims, make a great hook — the sky over the nuclear power plant "Fukushima-1" closed within 30 kilometers. March 15 morning, the second power unit started a fire and explosion. Apparently, the experts say, it is from this second reactor, and there was a powerful release of radiation.
Things were not the way to the third and the first block. It blasts a mixture of hydrogen and oxygen in the Saturday and Monday came under a roof space in which there are reactors. Durable concrete reactor vessels is not affected. In the second block was damaged reinforced concrete is a protective case. In all three cases, the cause of PE was overheating. Plain and backup cooling systems have failed.
According to the head of department equipment and operation of nuclear power plants Obninsk Institute of Nuclear Power Sergei Leskinen, lack of water in the core led to the fact that it began to overheat, the water of the core into a vapor. "Part of the fuel in the reactor core could well have melted, but it can not lead to a nuclear explosion, reactor physics itself does not allow this," — said the expert.
Experts say that every hour through the core, that is, an area where actually is the fission of uranium needed to pump 50 to 80 thousand cubic meters of water, or fuel assemblies overheat and begin to melt. To do this under normal circumstances are special powerful pumps and steam turbine plant.
"Turbine sets no, they lost it, accordingly, no steam, no drive for this turbopitatelnogo pump and fire hydrants to upload a similar amount of sea water into the reactor is impossible" — said the prow of the Public Council of "Rosatom" Vladimir Kuznetsov.
The process of the accident at the second power after the explosion could develop as follows. Water level has dropped to the lowest level. The so-called fuel rods began to overheat, and at temperatures above 2 thousand degrees Celsius — to melt. Then the whole mass fell to the bottom of the concrete hull, which was damaged. This explains the sharp increase in the radiation level at the station. The only figures that were presented today by Japan — radiation levels of 400 millisieverts per hour. "The average dose received by the population of the globe, 2.4 mSv, the dose received by the population of Finland from natural background of 7.5 mSv, Republic of Altai — 9.7, there are areas where they receive, and 10, and in this sense it is a natural dose natural radiation, which, of course, no harm can not be, — said the first deputy director of the Institute for Safe Development of RAS Rafael Harutyunyan. — A simple thing — full scan, so to speak, she 10 millisieverts, there are people who, for a test 2-3 years gaining 40-30 mSv. "
In this case we are talking about the accumulated exposure over the year. Radiation levels of 400 millisieverts per hour was recorded at the site near the fourth nuclear power plant unit at 10 am local time. This means that a lethal dose of a man who does not wear a protective suit, could not get here in just 2-3 hours.
This morning, Japanese Prime Minister Naoto Kan has publicly insisted that the station personnel not to leave their jobs. Moreover, according to Japanese media reports, the prime minister excoriated the management of the company, which owns the nuclear power plant. Supposedly even the ever discreet Naoto Kan stormed into office with the words, "What the hell is going on?" It turns on Saturday, the first explosion at the plant, Prime Minister learned from press reports. Today Naoto Kan again addressed the nation, calling on all those who have not yet had time to leave the 20-kilometer zone around the plant, for emergency evacuation. Within a radius of 30 kilometers in no way be out of their homes, said the prime minister. "We are taking all necessary measures to stabilize the situation, but there is a possibility of a new radiation leak" — Naoto Kan said.
Happy company that operates a nuclear power plant, announced that the background radiation is increased so that the staff can not be in the control rooms of power units. Who removes the consequences of the accident — is not clear. Also not clear for how long they can work there. For example, during the aftermath of the Chernobyl accident helicopter hover over the roof of the destroyed reactor is not more than a minute, and they received a very high dose of radiation.
In the pictures you can see from space, as now looks station "Fukushima-1": the building on the first and third reactor is destroyed, the building of the second reactor remained intact, but this reactor is now the greatest danger. He damaged internal — robust housing.
Day it was reported that a serious situation exists in spent nuclear fuel at the plant "Fukushima-1". This is a large swimming pool next to the fourth block in which the water is stored here are similar to them or fuel assemblies. They have already been removed from the reactor and the technology that must be cooled for several years.
"If the water boils away, there will begin some unpredictable reactions, chemical, radiochemical reactions, radio-chemical reactions, — the head of the program for nuclear radiation safety Socio-Ecological Union, Alexei Yablokov. — This is also a great danger, because a lot of radionuclides." According to Yablokov, "it's clear that will be contaminated and polluted large areas for tens of kilometers."
Radioactive trail now extends to the south-east, in the direction of Tokyo. The closer to the station, the more the level of contamination. In the future, given the wind rose in the region, and the clouds will move in the direction of the Pacific Ocean and may have spread far enough.
The accident in Japan has caused a wave of disturbing statements from foreign governments. Many already say that we are ready to seriously reconsider their attitude to nuclear power. For example, Germany, today announced that the 3-month stop the seven reactors built before 1980. And the European Union has decided to immediately check all their nuclear power plants. The fact that a thorough revision of plans to build nuclear power plants, announced Lithuania, Bulgaria, Brazil, Malaysia and Thailand.

 

Maxim Semin

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