An underground Disposal Room in Panel 1 partially filled with drums and Standard Waste Boxes of contact-handled waste. A SWB has four filter ports and at least two filter vents. Ports without filters are plugged during transport. A SWB can hold four 55-gallon drums of waste. Drums are the most common container for TRU waste and are also filtered with at least one filter vent. The drums in this photograph are configured into 7-Packs and wrapped with plastic.

Waste containers are stacked 3 layers high and six columns wide in the disposal rooms. The large, hexagonal boxes on the top of the stacks are 'supersacks' of Magnesium Oxide (MgO). 'Backfill' of MgO is the only 'engineered barrier' at WIPP. The small sacks hanging from the sides of the containers are 'minisacks' which are no longer being used at WIPP. Note the wire mesh, rebar and rockbolts holding the ceiling together. (USDOE)