Maxey Flat Nuclear Waste Site

1
Maxey Flat Nuclear Waste Site

• Presented by
• Jonathan Silvester
• Oliver Kiernan

2
Maxey Flat Site

• Located in Fleming County, Kentucky
• Low level Nuclear Disposal Facility
• Isolate waste from people and the environment
  until radionuclides have decayed to non
  hazardous levels
• 1 of 6 waste disposal sites created in the US
• Approximately 663 people live within 2.5 miles
• Located on one of the largest flat top ridges in
  the area

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History of Maxey Flat Site

• 1962 - Nuclear Engineering Company bought site
• 1963 - Application to bury nuclear waste granted
• 1974 Plutonium detected outside site boundary
• 1977 Site Closed
• 1986 Site placed on National Priorities List
• 1995 Clean up of site begins

4
Waste Disposal

• Served 832 corporations
• A 279 acre waste burial site
• Consisted of 52 trenches
• Hot Wells for special nuclear material
• 4,750,000 cubic feet of waste stored

5
Reasons for Failure

• Poor planning and design
• Site soil wrong composition
• Highly permeable soil used for Protective Cap
• Poor site organisation and management
• Spills cleaned with standard earth moving
  equipment
• Poorly placed waste
• Waste not in suitable containers
• Poor government legislation
• Guidelines of high and low level radioactive
  waste

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Reasons for failure Bathtub Effect

• Build up of water in trenches caused by greater
  seepage into trench
• Capped with 3-10 feet of soil
• Not concrete or steel
• Collapsed due to rain water
• Water became radioactive
• Nuclear waste overflowed out of the trenches

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Impacts

• Radiation detected extremely small
• 1 in 40 million chance of getting cancer
• No major health or environmental implications
• However, great concerns with
• Rainwater runoff
• Groundwater flow
• Air Born Pollutants
• Immediate closure of site
• Multi million pound clean up operation

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Contaminants

• Contaminated all areas of the site
• Indicator contaminants were of concern
• Radionuclides
• Tritium
• Cobalt-60
• Strontium-90
• Plutonium-238/239
• Tritium was of the greatest concern
• Most abundant
• Most mobile
• Easily able to form tritiated water

• Non Radionuclides
• Arsenic
• Benzene
• Lead
• Cyanide

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Clean up Process

• Main objectives
• Minimize infiltration/ mitigation of rainwater
  and ground
• Stabilize site for long term cap
• Reduce risks to human health and environment
• 7 alternative remedial solutions
• Dynamic Compaction
• Vertical infiltration prevention methods
• Horizontal infiltration prevention methods
• All subjected against 9 criteria's
• Chosen solution Natural Stabilization
• Allow materials to stabilise
• Permanent cap
• Reviews every 5 years

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Natural stabilization

• Consists of 4 stages
• 1) Initial Closure period Completed May 2003
• Remove, solidify store leachate
• Demolish buildings grade site
• Initial cap placed
• Install Monitoring equipment
• 2) Interim maintenance Current stage (35
  100years)
• Monitor natural stabilisation
• Provide buffer zone
• 3) Final closure period
• Installation of Final cap
• 4) Custodial maintenance
• Begins once final cap completed