A nuclear and radiation accident is defined by the International Atomic Energy Agency as “an event that has led to significant consequences to people, the environment or the facility. Examples include lethal effects to individuals, large radioactivity release to the environment, or reactor core melt.” The prime example of a “major nuclear accident” is one in which a reactor core is damaged and significant amounts of radiation are released, such as in the Chernobyl Disaster in 1986.
Effect on life
Normally reactor sites pose no health threat and strict regulations are in place to protect the public. But, natural disasters cannot be predicted and machinery malfunctions and human error is always a possibility, mix these two and the results can be deadly. Any living organism can be killed by radiation if exposed to a large enough dose, but the lethal dose varies greatly between species. Humans are among the most radiosensitive of all living organisms and can be affected somatically – which is damage to the individual, and genetically – which is damage to one’s offspring Although a dose of just 25 rems causes some detectable changes in blood, doses to near 100 rems usually have no immediate harmful effects. Doses above 100 rems cause the first signs of radiation sickness including:
o some loss of white blood cells
Doses of 300 rems or more cause temporary hair loss, but also more significant internal harm, including damage to nerve cells and the cells that line the digestive tract. Severe loss of white blood cells, which are the body’s main defense against infection, makes radiation victims highly vulnerable to disease. Radiation also reduces production of blood platelets, which aid blood clotting, so victims of radiation sickness are also vulnerable to hemorrhaging. Half of all people exposed to 450 rems die, and doses of 800 rems or more are always fatal. Besides the symptoms mentioned above, these people also suffer from fever and diarrhea. As of yet, there is no effective treatment–so death occurs within two to fourteen days. In time, for survivors, diseases such as leukemia (cancer of the blood), lung cancer, thyroid cancer, breast cancer, and cancers of other organs can appear due to the radiation received. Example
The Kyshtym disaster was a radiation contamination incident that occurred on 29 September 1957 at Mayak, a nuclear fuel reprocessing plant in Russia (then a part of the Soviet Union). It measured as a Level 6 disaster on the International Nuclear Event Scale, making it the third most serious nuclear accident ever recorded (after the Chernobyl disaster, and Fukushima Daiichi nuclear disaster, both Level 7 on the INES). The event occurred in the town of Ozyorsk, a closed city built around the Mayak plant. Since Ozyorsk/Mayak (also known as Chelyabinsk-40 and Chelyabinsk-65) was not marked on maps, the disaster was named after Kyshtym, the nearest known town. 8,015 people had died within the preceding 32 years as a result of the accident.”
By contrast, only 6000 death certificates have been found for residents of the Tech riverside between 1950 and 1982 from all causes of death, though perhaps the Soviet study considered a larger geographic area affected by the airborne plume. The most commonly quoted estimate is 200 deaths due to cancer, but the origin of this number is not clear. More recent epidemiological studies suggest that around 49 to 55 cancer deaths among riverside residents can be associated to radiation exposure. This would include the effects of all radioactive releases into the river, 98% of which happened long before the 1957 accident, but it would not include the effects of the airborne plume that was carried north-east.
The level of radiation in Ozyorsk itself is claimed to be safe for humans, but the area of EURT is still heavily contaminated with radioactivity. To reduce the spread of radioactive contamination after the accident, contaminated soil was excavated and stockpiled in fenced enclosures that were called “graveyards of the earth”. The Soviet government in 1968 disguised the EURT area by creating the East-Ural Nature Reserve, which prohibited any unauthorised access to the affected area.