• Contains elements with atomic numbers greater than 92, has radioactivity greater than 100 nanocuries per gram and a half-life of more than 20 years.
• Waste stored aboveground is governed by the 1995 Settlement Agreement/Court Order.
• Chiefly resulted from Cold War weapons production
• Requires permanent isolation for disposal

• Contains long-lived radionuclides and hazardous substances such as acids, caustics, metals and organic solvents
• Exists in both liquid and solid forms
• Generated by only a few processes (from spent nuclear fuel reprocessing at the INEEL)
• Requires permanent isolation for disposal

Mixed Low-Level Waste (MLLW)

• Contains components of both low-level radioactive and hazardous waste
• May contain various radionuclides
• Often includes metals, organic solvents, cyanides, explosive compounds, acids and caustics
• Generated by nuclear defense, facility dismantlement and research activities
• Often requires new treatment technologies
• Will be finally disposed of off site

• Defined by not meeting the definitions for high-level, transuranic, spent nuclear fuel or by-product materials
• Does not contain hazardous substances
• Generated by most nuclear activities
• Chiefly consists of contaminated wood, soils, tools and equipment (at the INEEL)
• Often incinerated, sized or compacted before disposal in below-ground containers or vaults

• Contains corrosive, ignitable, reactive or toxic materials
• Does not contain radioactive components
• Generated by everyday activities
• Often consists of process waste, organic solvents, lead and lead-contaminated debris
• Characterized and shipped out of Idaho to commercial treatment and disposal facilities within a 90-day time frame

• Consists of solid waste debris such as asbestos, paper or wood
• Does not contain hazardous or radioactive components Generated by industrial activities