Mixed Waste Acceptance
Presentation to IAEA Disponet
Workshop on Waste Acceptance Criteria for Disposal of Very Low and Low Level Waste
28-30 September 2010, Peine, Germany
K Loveland, EnergySolutions, USA
Introduction
• The USA manages wastes for disposal in accordance with the radiological, hazardous and physical properties of the waste
• Wastes that are both radiological and hazardous in nature are subject to two regulatory paradigms and called Mixed Wastes
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• This presentation will:
– Further define the regulatory
basis for Mixed Wastes in the
USA
– Discuss examples of acceptable
treatment methods for Mixed
Wastes to meet waste
acceptance criteria for disposal
– Discuss examples of compliant
land disposal of Mixed Wastes
Regulatory Basis of Mixed Waste
What is Hazardous Waste:
• A subset of solid wastes that pose substantial or potential threats to public health or the environment and meet any of the following criteria:
– Is specifically listed as a hazardous waste by the US Environmental Protection Agency (EPA) – termed listed Mixed Waste
– Exhibits one or more of the characteristics of hazardous waste (ignitability, corrosivity, reactivity, and/or toxicity) – termed characteristic Mixed Waste
– Is generated by the treatment of hazardous waste; or is contained in a hazardous waste
What is Mixed Waste: A hazardous waste that is also a radioactive waste
• The US EPA governs the management, treatment and disposal of hazardous chemicals through the Resource Conservation and Recovery Act (RCRA) and the Toxic Substances Control Act (TSCA)
• These regulations are administered separately from radiological regulations (such as Nuclear Regulatory Commission requirements) and are notsubservient to radiological regulations – both must be considered prior to determining appropriate disposal
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Regulatory Basis of Mixed Waste (cont’d)
Two driving regulatory policies:
• RCRA - enacted in 1976 - set national goals for:
– Protecting human health and the environment from the potential
hazards of waste disposal
– Conserving energy and natural resources
– Reducing the amount of waste generated
– Ensuring that wastes are managed in an environmentally sound
manner
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• TSCA – also enacted in 1976 –regulates the use and disposal of polychlorinated biphenyls (PCBs) and asbestos.
Regulatory Basis of Mixed Waste (cont’d)
The US EPA identifies hazardous waste for purposes of management, treatment, and disposal as either Characteristic or Listed (identified by EPA Waste Codes)
• Characteristic Waste (D-codes wastes): A radioactive waste is considered a characteristic Mixed Waste if it exhibits any of the following characteristics:
– Ignitability (D001) – typically liquids with a flash point <60 degrees C
– Corrosivity (D002) – typically liquids with a pH < 2 or >12.5
– Reactivity (D003)– reacts violently with water – examples are reactive metals (e.g. sodium, lithium)
– Toxicity (D004-D0043) – hazardous substances (heavy metals, volatile and semi-volatile organics, pesticides/herbicides) exceeding risk-based regulatory threshold concentrations of leachate expressed in units of mg/L
• Listed Waste (F, K, P, and U – coded wastes): A radioactive waste is considered a listed Mixed Waste if it exhibits the following characteristics:
– F-listed waste codes are from non-specific sources (e.g. F001 spent halogenated solvents from decreasing operations)
– K-listed waste codes are from specific sources (e.g. K001 bottom sediment sludge from wood preserving operations)
– P and U-coded wastes (discarded or off-specification chemicals)
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Treatment to Meet Disposal WAC
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Mixed Waste Treatment to meet Land Disposal Requirements (LDR)
• The US EPA specifies treatment requirements/standards for all hazardous wastes - characteristic or listed – and Mixed Wastes are no exception
• Waste treatment must occur or be verified not to be required prior to disposal
• A subset of US radioactive waste disposal facilities have been permitted to allow disposal of low concentrations of Mixed Waste (e.g., CERCLA cells in Oak Ridge, Hanford, Fernald, Idaho)
Treatment to Meet Disposal WAC (cont’d)
Treatment standards fall into three categories:
• Concentration-based standards – typically expressed as total concentrations
and verified through sampling
• Technology-based standards – successful treatment of specific wastes is
based on use of a specified technology rather than achieving a concentration
threshold
– Examples of technology based standards are: Deactivation, Incineration,
Stabilization, Chemical Oxidation, and Amalgamation
• Alternative standards – the US EPA has established alternate technology-
based treatment standards for debris, regardless of waste code.
– The most widely utilized alternative debris treatment standard is macroencapsulation
– Macroencapsulation is the application of surface coating materials such as polymeric
organics, or use of a jacket of inert inorganic materials to substantially reduce
surface exposure to potential leaching media.
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Treatment to Meet Disposal WAC (cont’d)
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Is the waste characteristic? (usually determined by laboratory analysis)
Is the waste listed? (determined by the source/process)
Does the waste require
treatment prior to disposal?
Treatment to meet LDR
Is the waste hazardous?No
No
40 CFR 261
40 CFR 268
Disposal
Treatment to Meet Disposal WAC (cont’d)
Treatment Example: Stabilization
• Stabilization of RCRA metals by
mixing reagents with waste
• Shredder used for debris prior to
stabilization
• Desire soil-like treated waste
stream for disposal
• Treatability study performed
during approval of waste for
treatment/disposal
• Sampling post-treatment to verify
treatment successful
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Treatment to Meet Disposal WAC (cont’d)
Treatment Example:
Macroencapsulation
• Radioactive Lead Solids
• Alternative Treatment Standard
for Hazardous Debris
– > 60 mm particle size (tennis ball)
– “Primarily” debris in the package
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Treatment to Meet Disposal WAC (cont’d)
Treatment Example:
Macroencapsulation
• Macroencapsulation vaults
• Large components
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Treatment to Meet Disposal WAC (cont’d)
Treatment Example: Vacuum-Assisted
Thermal Desorption
• Separation of organics for further
treatment
• Incineration of condensate (organic
liquid)
• Verification of residue for LDR
compliance and final disposal
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VENT TO
ATMOSPHERE
MIXED
WASTE
RAD SOLIDS
<UTS
FURNACE
STACK
FILTRATION
SYSTEMNON-RAD
CONDENSATEN2
OIL
WATER
Land Disposal of Mixed Wastes
Land Disposal of Compliant Mixed Waste
• Mixed waste cannot be land disposed until specified US EPA treatment
standards are met.
• Design and construction of VLLW/LLW Mixed Waste disposal cells are
evaluated for performance in regards to both the radioactive and hazardous
properities of the proposed waste
• Some disposal requirements, such as a leachate collection system, may be
required to dispose of Mixed Wastes
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Land Disposal of Mixed Wastes (cont’d)
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Excavate ~ 10 ft.Install and Approve Clay Liner
Layers of Waste Compacted and Disposed
Install Radon Barrier (Clay Cap) 2 ft (61 cm)
Install Engineered Cover
Rip Rap 18 in (48 cm)
Type A Filter 6 in (15 cm)
Sac. Soil 12 in (30 cm)
Type B Filter 6 in(15 cm)
Geomembrane
Land Disposal of Mixed Wastes (cont’d)
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Nevada National Security Site (formerly Nevada Test Site) Area 3
Thank You
ANY QUESTIONS?
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