Chernobyl Consequences and Solutions

1
Chernobyl Consequences and Solutions

• Amy Banks 4005714
• Sam Blackburn 4003810

H23 G07 Environmental Geotechnics Presentation
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Background and History

• April 26th 1986 Chernobyl Nuclear Power Plant
  suffered a horrendous accident.
• Nuclear Fallout scattered over Ukraine, Belarus
  (70), Russia.
• Fallout found as far away as Wales (most of the
  Northern Hemisphere experienced some
  contamination).
• 50 deaths directly attributed so far to the
  accident, however recent studies estimate this
  will rise to 4,000.
• Substantial economic, social and healthcare
  effects.
• Initial concerns were based around radioactive
  iodine, but now theres increasing concern around
  the contamination of soil by Strontium-90 and
  Caesium-137.

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Chemicals of Main Concern

• Caesium-137 (Gamma rays)
• Highly Toxic with a half life of 30 years
• Similar to Potassium
• Found in top soil
• Easily absorbed by plants and animals.
• 21 of Belarus Remains Contaminated

• Strontium-90 (Beta rays)
• Highly Toxic with a half life of 28 years
• Easily soluble in water, consequently difficult
  to track
• Contributes to bone disorders and diseases,
  Substitutes for calcium in bone
• 80 Strontium now passed into natural cycles

4
Containing the Disaster

• Zone of Alienation (30 km Radius).
• A large concrete slab placed underneath the
  reactor to prevent radioactive material leaching
  into the groundwater.
• Measures to cultivate clean products/food
  stuffs in contaminated areas.
• Combining lime, with manure and mineral
  fertilisers effective in reducing caesium content
  by a factor of 30.
• Prussian blue.
• Radical Improvement.

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Radical Improvement

• Most effective countermeasure for coping with
  radioactive contamination from the nuclear
  fallout.
• Involves the ploughing, reseeding and application
  of NPK fertilisers (Nitrogen, Phosphorus,
  Potassium) and lime.
• Ploughing diluted radioactive contamination in
  upper layers of soil where plant roots absorb
  their nutrients.
• Fertilisers increased plant production, therefore
  diluted the radioactivity in the plant.
• Repeated fertilisation was needed at some sites.
• Reduction by a factor of 2-4 in soil plant
  transfer of strontium-90.

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Alternative Measures

• Using plants to modify the environment by
  absorbing strontium-90 and caesium-137
  (Phyto-Remediation)
• The Plants absorb the harmful radioactive waste
  and through chemical process transform it into
  less harmful waste.
• Accumulation/Extraction/Degradation.
• Sunflowers already effective, and research into
  the use of Indian Mustard Plants.
• Plant clean ups between a tenth and a quarter of
  the cost of conventional methods.

7
Chernobyl Today / Tomorrow

• Last operating reactor at Chernobyl was
  permanently shut down on 14th December 2000.
• Original sarcophagus currently being stabilised.
• Construction contract for NSC (New Safe
  Confinement) will be awarded this year.
• Once NSC built, removal of original sarcophagus
  will take place.
• Fuel removal of reactors 1 to 3.