Presentation on theme: "What do you see in this picture? How does this picture make you feel? What questions come to mind when you see this picture?"— Presentation transcript:
What do you see in this picture? How does this picture make you feel? What questions come to mind when you see this picture?
What happened at Chernobyl? The disaster that occurred at a nuclear power plant in Chernobyl in the former USSR (now Ukraine) plant on April 25th 1986 is an example of the devastation that can occur when a nuclear reaction goes wrong. The Chernobyl nuclear power plant located 80 miles north of Kiev had 4 reactors and whilst testing reactor number 4 numerous safety procedures were disregarded.
Timeline of Events 26 April 1986, 1:23:00: A test of the cooling system begins in unit no. 4 of the Chernobyl power plant 26 April 1986, 1:23:40: The emergency shutdown fails. 26 April 1986, 1:23:44: The reactor in unit no. 4 runs out of control and explodes. 26 April 1986: In the town of Pripyat, 3 km away, there are 45,000 people, including 16,000 children. On 26 April 1986 they are enjoying the first warm Sunday of the spring. 26 April to 4 May 1986: Most of the radiation is released in the first ten days. 27 April to 5 May 1986: About 1800 helicopter flights deposit around 5000 tons of extinguishing materials such as sand and lead onto the burning reactor. 27 April 1986: The inhabitants of the Pripyat power plant settlement are evacuated. 28 April 1986, 21:00: The Soviet news agency Tass announces that there has been an accident at the Chernobyl nuclear power station and that there have been casualties. An investigative committee is established.
28 April 1986, 23:00: A Danish nuclear research laboratory announces that an MCA (maximum credible accident) has occurred in the Chernobyl nuclear reactor. 29 April 1986: The MCA at Chernobyl is first reported in German newscasts. Up to 5 May 1986: Over the ten days following the accident, 130,000 people are evacuated from a 20 mile zone around the reactor. 6 May 1986: The release of radiation stops. 15 to 16 May 1986: New fires break out and more radiation is released. 23 May 1986: A Soviet government committee orders the distribution of iodine preparations. At this point, such prophylaxis is of no medical value. Radioactive iodine is only active for ten days, and will already have accumulated in the thyroid glands of the inhabitants of the contaminated territories.
Where did the radiation go? An estimated 100 to 150 million curies of radiation, primarily radioactive isotopes of iodine and cesium, escaped into the atmosphere At present, more than five million people live in areas that are considered to be contaminated with radioactive materials from the Chernobyl accident
What is low versus high level radioactive waste? Low-level waste includes items that have become contaminated with radioactive material or have become radioactive through exposure to neutron radiation. This waste typically consists of contaminated protective shoe covers and clothing, wiping rags, mops, filters, reactor water treatment residues, equipments and tools, luminous dials, medical tubes, swabs, injection needles, syringes, and laboratory animal carcasses and tissues. The radioactivity can range from just above background levels found in nature to very highly radioactive in certain cases such as parts from inside the reactor vessel in a nuclear power plant. Low-level waste is typically stored on-site
Where do we store it? High-Level Radioactive Waste is: the irradiated fuel from the cores of nuclear reactors The liquid and sludge wastes that are left over after irradiated fuel has been reprocessed (a procedure used to extract uranium and plutonium) The solid that would result from efforts to solidify that liquid and sludge from reprocessing.
How did they contain the radioactivity? Finally, workers erected an enormous concrete-and-steel shell or sarcophagus over the damaged reactor to prevent radioactive materials, including gases and dust, from escaping.
How was human health affected? Because of contaminated milk, the thyroids of many children were heavily exposed to radioactive iodine. It is roughly estimated that the total number of deaths from cancers caused by Chernobyl may reach 4000 among the 600,000 people having received the greatest exposures.
Chernobyls Legacy! Thousands of those who were children and adolescents at the time of the accident have developed thyroid cancer as a result of exposure to radioactive iodine. The majority of those cancers have been treated successfully.
How was the environment affected? Regarding agriculture, the contamination of crops, meat, and milk with short-lived radioactive iodine was a major concern in the early months after the accident. Forest food products such as berries, mushrooms, and game contain particularly high levels of long- lived radioactive cesium and this contamination is expected to remain high for several decades. As a result of the accident, water bodies and fish became contaminated with radioactive materials. The contamination soon decreased as a result of dilution and decay but some of the materials remained trapped in the soils around contaminated rivers and lakes.
Are we safe? In the year of the accident, a shelter was built to contain the damaged reactor. The shelter has some imperfections because it was built quickly and under very difficult conditions, as the construction personnel was being exposed to severe radiation levels.
What are the social and economic costs of the Chernobyl accident? In your opinion, what should the role of the government be in such an accident?