GEOLOGY

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GEOLOGY WASTE DISPOSAL
Anne Wilkins 15th October 2002
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WASTE

• Waste can be classified as either
• Managed (Controlled) Waste
• OR
• Unmanaged (Uncontrolled) Waste

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CONTROLLED WASTE

• 1. Inert Waste e.g. builders rubble
• 2. Non-hazardous Waste e.g. wood paper
• 3. Difficult Waste e.g. batteries, car tyres
• 4. Hazardous Waste e.g. radioactive
• 5. Toxic Waste e.g. petrochemical
• 6. Clinical Waste e.g. syringes, needles

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UNCONTROLLED WASTE

• 1. Mine Spoil
• 2. Quarry Spoil
• 3. Agricultural Wastes

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Geology Waste Disposal

• Nuclear Waste
• a) Radiation
• b) Sources of Nuclear
• Waste
• c) Types of Nuclear Waste
• d) Disposal Of Nuclear Waste

• Municipal Waste
• a) Sources of Waste
• b) Historical Landfills
• c) Modern Landfill Site Selection

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RADIATION NUCLEAR WASTE
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IONISING RADIATION

• Elements consist of one or more isotopes with
  different atomic weights.
• Radioisotopes are unstable isotopes which change
  into another isotope, either stable or unstable,
  and in the process emit radiation.
• There are three main types of radiation.

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TYPES OF RADIATION
1. Alpha ? 2. Beta ? 3. Gamma ?
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RADIO-ISOTOPES
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RADIATION TERMS
Roentegen or Röntegen- Named after Wilhelm
Roentgen, the German scientist who discovered
X-rays in 1895. A unit of exposure measuring the
ionising ability of gamma radiation and X-rays in
air.
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RADIATION TERMS
Rad - (Radiation Absorbed Dose) A unit to
measure the amount of energy from any type of
ionising radiation (e.g., alpha, beta and gamma)
absorbed by any medium (e.g. water, tissue, air).
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RADIATION TERMS
Rem - (Roentgen Equivalent Man) This relates the
absorbed radiation dose in human tissue to its
effective biological damage. Not all radiation
has the same biological effect, even for the same
amount of absorbed dose. Alpha radiation is 10
times more damaging than either beta or gamma
radiation.
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EFFECTS OF RADIATION
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BACKGROUND RADIATION

• Natural Sources
• Rocks
• Cosmic Rays
• 0.1 rem per year

• Man-Made Sources
• Colour TV
• Irradiated Foods
• Medical Diagnosis
• 0.2 rem per year

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SOURCES OF NUCLEAR WASTE
1. MEDICAL SOURCES
2. INDUSTRIAL SOURCES
3. MILITARY SOURCES
4. NUCLEAR POWER STATIONS
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NUCLEAR WASTE
1. Low Level Waste (LLW) 2. Intermediate
Level Waste (ILW) 3. High Level Waste
(HLW)
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LOW LEVEL WASTE

• 1. General term for all radioactive wastes other
  than those produced from nuclear reactors. Low
  level wastes are derived from medical, research
  and industrial activities.
• 2. Contains very little radioactivity often at a
  level below natural background.
• 3. Usually contains very little or zero
  percentage of alpha emitting radioisotopes.
• 4. Low risk to human health.

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HIGH LEVEL WASTE
1. Radioactive waste produced from nuclear power
reactors and the nuclear fuel cycle. 2. Highly
radioactive and heat producing. 3. Large
percentage of long lived alpha emitting
radioisotopes. 4. Very hazardous to human health.
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LOW LEVEL WASTE DISPOSAL

• LIQUID LLW
• Ground Percolation
• Deep Well Injection
• Grout Injection

• SOLID LLW
• Sea Dumping
• Disposal Mined Cavity
• Shallow Land Burial

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HIGH LEVEL WASTE DISPOSAL

• TECHNOLOGY
• Space
• Transmutation
• Partitioning
• Ice Sheet Emplacement

• GEOLOGY
• Sea Bed Disposal
• Very Deep Boreholes
• Deep Underground Melting
• Deep Mined Cavities

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MUNICIPAL WASTE DISPOSAL
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WHATS IN A LANDFILL ?
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SOURCES OF MUNICIPAL WASTE

• In 1992, in Britain, 137 million tonnes of
  controlled waste consisted of
• 1. Household Waste - 20 million tonnes
• 2. Commercial Waste - 15 million tonnes
• 3. Industrial Waste - 32 million tonnes
• 4. Demolition/Construction - 69 million tonnes
• 5. Sewage Sludge - 1 million tonnes
• 90 to 95 was destined for landfill

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HISTORICAL LANDFILLS

• Most common places for historical dumps
• Topographical Anomalies
• a) Low lying areas, e.g. peat bogs
• b) Valley flood plains
• Mined Areas
• a) Sand and gravel quarries
• b) Rock quarries

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LANDFILLS -Environmental Impacts

• 1. Landfill Gas
• 2. Leachate
• 3. Litter
• 4. Odour
• 5. Dust
• 6. Site Security

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HISTORICAL LANDFILLS

• Leachate can contaminate surface water and
  groundwater including domestic water supplies.

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MODERN LANDFILLS

• Landfill sites can be of two types
• 1. Total containment sites
• 2. Slow dispersal sites

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MODERN LANDFILL SITE SELECTION

• 1. Strategic Planning
• 2. Site Assessment
• 3. Environmental Impact Assessment

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MODERN LANDFILL SITE ASSESSMENT

• 1. Nature of Wastes
• 2. Topography and Structure
• 3. Bedrock and Surface Geology
• 4. Hydrogeological Regime

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NATURE OF WASTE

• Category 1
• Hazardous Waste - high risk to groundwater
• Category 2
• Domestic and Industrial Waste
• Category 3
• Solid Inert Waste - no risk to groundwater

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GAS FLARE STACK
Landfill gas is controlled through a system that
collects gas in wells and conveys it to either a
flare where it is burned and destroyed or to a
mini-power plant for the generation of electricity
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CONCLUSION

• The Type Of Waste Dictates How We Dispose Of It
• The Geology Of An Area Dictates Where We Can
  Dispose Of It