Transcript Slide 1

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?
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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
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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.
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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?
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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?
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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?
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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.
Yucca Mountain Nevada
How did they contain the
radioactivity?
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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?
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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.
Chernobyl’s Legacy!
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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?
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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 longlived 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?
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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?
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In your opinion, what should the role of the
government be in such an accident?
References
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www. greenfacts.org/en/chernobyl/#1
www.inmotion,magnumphotos.com/es
says/chernobyl.aspx