Fukushima-1 nuclear power plant goes on record - as the duration of emissions, and their volumes. Emissions of radiation from the reactor and spent fuel storage basins at the plant Fukushima-1 continues the seventeenth day. Dangerous radionuclides fall and into the atmosphere and the ocean. How long will it last, can not say no. Yesterday reported the plutonium contamination ... is finished. Worst fears continue to come true. Next to the emergency plant Fukushima-1 detected plutonium. Plutonium - it is a long-lived alpha-emitting artificial radionuclides that are formed in working on the uranium fuel nuclear reactors.Under normal conditions, plutonium is not volatile, but during the most serious accidents such as Chernobyl or Fukushima, plutonium into the environment, to stay with us for hundreds of thousands of years.
Plutonium
Late in the evening on March 28 operating nuclear power plant emergency organization, the company TEPCO (TEPCO) said at a press conference that in soil samples taken at five locations at the site of Fukushima nuclear power plant-1 were detected isotopes of plutonium: plutonium 238, 239 and 240. Soil samples were taken 21 and 22 March, the Japanese took 6 days for their research and publication of results.
According to TEPCO in one sample of plutonium-238 is about 0.54 Bq / kg dry soil, and the mixture of plutonium isotopes 239 and 240 in the other two samples - 1.2 Bq / kg.From these data, it is unclear what is the density of alpha radioactive isotopes, how many becquerels per square meter.
"The ratio of activity of plutonium-238 found in the soil of industrial area, the activity of plutonium-239 and 240 is 2.0 and 0.94, respectively.This exceeds the ratio of 0.026, which is characteristic of atmospheric nuclear tests were, therefore, that plutonium is the result of a recent accident ", - states TEPCO.
There remains the question comes whether the plutonium in the environment only because of the damaged reactor with steam and (or) leakage, or also from the emergency reactor spent fuel storage of spent nuclear fuel. On the third unit to use uranium-plutonium fuel (so-called MOX fuel), it is possible that this particular unit has contributed to the detection of the diversion.
Plutonium contamination undoubtedly dangerous.It is known that over time, the plutonium oxide from the inactive form goes into soluble compounds, it is possible to expect that the plutonium will be left to lie at the site of accident. TEPCO says that the detected levels of contamination are not dangerous to health.
Chief Cabinet Secretary Yukio Edano believes that a leak of plutonium confirms that the melting of nuclear fuel: "It is likely that the appearance of plutonium associated with the situation with the fuel rods.They were able to partially melt.
Prime Minister of Japan, Naoto Kan said that the emergency NPP Fukushima-1 "remains an unpredictable situation that requires the government to maximum exertion.
Radiation fallout continues
IAEA confirms that there is evidence of loss of radionuclides already in 17 prefectures in Japan. In the seven prefectures in the daily rate are: iodine-131 - less than 500 becquerels per square meter. meter, cesium-137 - less than 100 becquerels per square meter. meter. It is important to emphasize that we are talking about the daily precipitation and the concentration of radioactive iodine, cesium and other radionuclides will rise.AGATE report: "March 26 greatest magnitude [fallout radionuclides] observed in Yamagata (Yamagata): 7500 becquerels per square meter. meter for iodine-131 and 1200 Bq per square meter. meter for the cesium-137. It also reported that at distances of 30-41 km from the power plant pollution beta and gamma radionuclides is from 0,03 to 3,1 Megabekkerel per sq. km. meter, which represents a very significant amount.
Radionuclides in drinking water and food
At the moment, remain in force recommendations for the Prohibition of drinking tap water due to excess iodine-131 in seven regions (for children and for children and adults - in one).Samples of milk with a higher concentration of iodine-131 from 23 to 25 March were found in five prefectures, with a high concentration of cesium-137 - one (prefektkra Chiba (Chiba)).
Although the content of these radionuclides in breast milk following the "norms" set in Japan, with their consumption of the risks of artificial radionuclides to get inside the body, which leads to internal exposure is many times more dangerous than the external from natural background radiation or x-ray.
But there is excess temporarily installed at the time of the disaster rules.The IAEA said: "In the three prefectures of Chiba, Ibaraki and Tochigi (Chiba, Ibaraki, Tochigi), iodine-131 found in celery, parsley, spinach and other leafy vegetables in concentrations prevyshayuschin established by the Japanese authorities. Cesium-137 has also been detected in quantities exceeding the limits in one sample of spinach on 24 March in the prefecture of Tochigi.
It is clear that emissions are continuing, territory, water and food continue to pollute.In the short term for the inhabitants of Japan represents a special danger of iodine-131, which is getting into the body, accumulates in the thyroid gland, exposing her to radiation as a result of which may have dysfunction of vital organs and even cancers.
But the half-life of radioactive iodine about 8 days, so we can assume that it is completely disintegrate in 80 days.That is 2,5 months infested products and territories will be free from radioactive iodine. Spinach is unlikely dolezhit until this time, and milk may well be processed into powder ...
A completely different situation with cesium-137, half-life - 30 years. He just completely fall apart after 300 years. That is, areas contaminated by cesium hundreds of years would be dangerous and in Japan developed its own zone - as Chernobyl or the result of an accident in 1957 East-Ural radioactive trace ...
Radiation in the ocean
March 26 TEPCO (TEPCO) and the Agency of Nuclear and Industrial Safety in Japan revealed the results of measurements of radioactive contamination of the ocean.At 330 meters the concentration of radionuclides in the tens, hundreds or thousands of times the limit - iodine-131 - 50 Bq / cu. cm (in excess of 1250 times), cesium-134 - 7 Bq / cu. cm (in excess of 117 times), cesium-137 - 7.2 Bq / cu. cm (in excess of 79.6 times). This is the result of the ongoing flushing into the ocean contamination and leakage from the damaged reactor and spent fuel pools.
TEPCO enmeshed in the millions ...
TEPCO announced that due to faulty instrument had previously been circulated false information about the dose of radiation near the damaged reactor.First was announced figure exceeded allowable is 10 million times.
Then the Japanese government formally apologized to the public for the incident, and "calm" - even serviceable devices show excess of the norms of 100 thousand times. Obviously, the radionuclides coming from the damaged reactor and ponds and exceeding standards in hundreds of thousands of times - not the limit.
"Do not spray the radiation!", A poster on anti-nuclear demonstration in Tokyo, March 27, 2011
How long will it last?
At a briefing in Vienna on March 27 the IAEA continues to say that the situation on emergency nuclear plant is still very serious. "On the same day in Tokyo, a mass anti-nuclear demonstration. Opposing the use of atomic energy in Japancontinue.
Links on the subject material:
Nuclear accident in Japan: Lessons for Dummies
Japan: major accident at the reactor spent fuel storage of nuclear waste plant Fukushima
Nuclear accident in Japan: the situation is worsening with each passing hour
Wikileaks: The Japanese authorities have long been aware of nuclear insecurity
The accident at the nuclear power plant in Japan: radionuclides could reach Russia in the seafood