Chernobyl Exclusion Zone

In the Chernobyl Zone of Alienation (Ukrainian Зона відчуження Чорнобильської АЕС, Russian Зона отчуждения Чернобыльской АЭС; literally "zone of alienation of the Chernobyl Nuclear Power Plant " ), is a restricted area, which in 1986, with a radius of 30 km around the stricken reactor block 4 the Chernobyl nuclear power plant was built on the territory of modern Ukraine.

The exclusion zone was set up to protect the residents in the surrounding areas especially before the radioactive fallout. This was accompanied by the evacuation of the cities of Pripyat and Chernobyl, and Kopatschi and other villages that were located within this area.

The access to this restricted area is controlled by the Ukrainian militia and is permitted only with permission.

Establishment of the closed area

After the first of the 44,000 inhabitants Prypjats were evacuated 37 hours after the accident, it was decided on 2 May 1986 to evacuate an area with a radius of about 30 km around the reactor, based on dose rate measurements. The evacuation was completed on May 6. First, about 116,000 people were taken from an area of about 3,500 km ². In subsequent years, this number increased to approximately 350,000 people.

Since the end of the Soviet Union are affected by the radioactive fallout areas Homelskaja Woblasz in Belarus and the Bryansk Oblast in Russia, which included at that time with the established restricted area, under their own management.

Released radionuclides

From 190.3 t radioactive material, which was located in the reactor core, were released into the environment in the first ten days from April 26 to May 5, 1986 6.7 t. Among other things, the following are particularly relevant radiotoxic nuclides were released:

• Strontium -90 (half-life: 28.8 years; β - emitters; replaces calcium in the body, for example in the bones )
• Iodine -131 (half-life: 8 days; β - emitters; accumulates strongly in the thyroid at )
• Caesium -137 (half-life: 30.1 years; β - emitters; decays in 95 % of cases barium - 137m, which after 2.5 min to barium -137 decays, and thus is largely responsible for the γ - radiation; cesium accumulates particularly in soils and fungi in )
• Plutonium -241 (half-life: 14.4 years; β - emitters; regenerated americium -241, plutonium binds to proteins and is deposited in the kidneys and liver from )
• Americium -241 (half-life: 432 years; α emitters; accumulates in bone (biological half-life: 50 years) and liver ( biological half-life: 20 years ) and the gonads (permanent) to )

Radiation exposure as a result of the nuclear accident

As a result of the nuclear accident, there were three mutually different phases in which different exposures have occurred.

Phase I is characterized by the first 20 days after the accident, in which there is acute short-lived radionuclides by (molybdenum -99, Tellur-132/Iod-132, xenon -133, iodine -131, Barium-140/Lanthan-140 ) radiation damage has come. Most of these nuclides were deposited on plants and the soil and led there to dose rates of up to 20 Gy / d in the first days after the accident. Released Radioiodnuklide led to thyroid damage in many vertebrates.

Phase II is the period from the summer to the autumn of 1986, fell into many of the short-lived radionuclides and long-lived radionuclides deposited on the biological, chemical or physical means in the environment, transformed and transported. The total dose rate of freigetzten in the accident radioactive material fell during this period to one-tenth of the initial value. Approx. 80 % of the radiation dose that has accumulated in plants and animals, were received within the first three months after the accident. 95 % of which resulted from beta radiation.

Phase III is the persisting phase in which the radiation exposure equivalent to 1% of the initial value and is mainly caused by the cesium -137 contamination. The propagation of plants as well as the influx of new animals into the restricted area provides here a very different bioaccumulation of the remaining radionuclides.

Living in the Zone

Returnees

In the restricted area of Chernobyl currently live 197 Samosjoli (Russian: самосёлы, Ukrainian: самосели - " settlers" ) (as of 2012). The returnees are mostly elderly people who have illegally returned after the evacuation in their former homeland. Today, they are tolerated by the state.

Flora and Fauna

The influence of radioactive contamination on the flora and fauna is controversial among scientists. Investigations especially in birds show albinism and smaller brain sizes, whereas the stock of mammals that live directly on the floor of the restricted area increases.

Plant

Since the accident occurred in late April, the damaging effects of the radioactive fallout in a period of increased growth was noticeable. Within the restricted zone activities of 0.7-3.9 GBq / m were measured. This led among other things to temporary sterility, growth and developmental disorders. Necroses, weathered leaf tips, disruption of photosynthesis and gene defects were observed. 40 % of winter wheat were affected. Abnormalities were still a few years later, identifiable. The strong dose rates in excess of 20 Gy / d were felt acutely in the radiosensitive conifers. In a coniferous forest, which stood west of the reactor is 1.5 km away, the radiation damage in yellowing of the needles were noticeable, which then fell off. The remaining needleless tree trunks gave the forest the name " Red Forest ". Meanwhile, this forest was leveled.

Animals

The time of the accident was also in the animals with a time of increased activity - reproduction and moulting - together. Within the 3-7 km zone around the reactor, the stock of invertebrates was reduced by a factor of 30. Dose rate of 3 Gy resulted in early mortality of the offspring and reproductive problems. Within a year, however, migrated other invertebrates from less contaminated areas in the restricted area, so that after two and a half years, no difference in the populations to control groups was more noticeable, although species diversity was significantly reduced. The total recovery of the diversity of invertebrates could not be detected until 1995. Current estimates of the authorities go from a stock of about 7000 wild boars, wolves, 150, 3000 deer, 1500 beavers, foxes, 1200, 15 lynx, several thousand elk and 280 bird species, many of which are rare or endangered.

Tourism

More recently, makes intensified day tourism in guided small groups, starting from the capital Kiev noticeable. The Government of Ukraine has announced plans to increase the number of tourists from 60,000 to one million.