Barrier

Barrier means any material or structure that prevents or substantially delays movement of water or radionuclides toward the accessible environment. For example, a barrier may be a geologic structure, a canister, a waste form with physical and chemical characteristics that significantly decrease the mobility of radionuclides, or a material placed over and around waste, provided that the material or structure substantially delays movement of water or radionuclides.

Source

40 CFR § 191.12

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Scoping language

Unless otherwise indicated in this subpart, all terms shall have the same meaning as in subpart A of this part.

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