ABSTRACT
Most subsurface containment strategies involve creating a vertical barrier wall and horizontal barrier under the waste to create a “bathtub” around the contaminated zone. However, the jet-grouting technology creates a simultaneous horizontal and vertical barrier by forming a solid monolith of the buried waste. As an example of a site for possible application, the Idaho National Engineering and Environmental Laboratory (INEEL) has more than 2 million cubic feet (56,000 cubic meters) of transuranic contaminated mixed waste commingled with 6 to 8 million cubic feet (169,000 to 224,000 cubic meters) of soil in shallow land burial. Improving the confinement for in situ disposal is one of the options being considered for this material. Another option is to retrieve the waste and process it for final disposal separately. The technology of jet grouting to create a monolith supports both of these potential decisions. For the disposal option, the resultant monolith is immune from subsidence, which can compromise any capping actions. In addition, the monolith lowers the water permeability through the material, thus reducing contaminant transport. If certain grouting agents are used, some contaminants can also be chemically stabilized such that they are not soluble in water and thus not prone to leaching and migration.
