Closed cryogenic barrier for containment of hazardous material migration in the earth

A closed cryogenic barrier confinement system extending about a predetermined volume extending downward beneath a surface region of the Earth, comprising:

• A. an array of barrier boreholes extending downward from spaced-apart locations on the periphery of said surface region,
• B. a plurality of ice columns, each column extending about one of said barrier boreholes,
• wherein position of the central axis of said barrier boreholes, the radii of said columns, and the lateral separations of said barrier boreholes are such that adjacent columns overlap, said overlapping columns collectively establishing a barrier enclosing said volume.

A method for maintaining a closed cryogenic barrier about a predetermined volume extending downward beneath a surface region of the Earth, said cryogenic barrier including an array of barrier boreholes extending downward from spaced-apart locations on the periphery of said surface region, and including ice columns in the Earth adjacent to said barrier boreholes, said columns extending axially along and radially about the central axes of said barrier boreholes, wherein the position of said central axes, the radii of said columns, and the lateral separations of said barrier boreholes are such that adjacent columns overlap, comprising the steps of:

• A. establishing a flow of refrigerant medium in said barrier boreholes,
• B. controlling the heat exchange between said flowing refrigerant medium in said barrier boreholes and portions of the Earth adjacent of said barrier boreholes whereby said adjacent ice columns are maintained overlapping.

A method for removing portions of a close cryogenic barrier about a predetermined volume extending downward beneath a surface region of the Earth, said cryogenic barrier including an array of barrier boreholes extending downward from spaced-apart locations on the periphery of said surface region and including ice columns in the Earth adjacent to said barrier boreholes extending axially along and radially about the central axes of said barrier boreholes, wherein the position of said central axes, the radii of said columns, and the lateral separation of said barrier boreholes are such that adjacent ice columns overlap, comprising the steps of:

• A. establishing a flow of refrigerant medium in said barrier boreholes,
• B. controlling the heat exchange between said flowing refrigerant medium in said barrier boreholes portions of the Earth adjacent to said barrier boreholes whereby said overlapping ice columns melt at least in part.