§ 960.4-2-5 Erosion.

(a) Qualifying condition. The site shall allow the underground facility to be placed at a depth such that erosional processes acting upon the surface will not be likely to lead to radionuclide releases greater than those allowable under the requirements specified in § 960.4-1. In predicting the likelihood of potentially disruptive erosional processes, the DOE will consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the geologic setting during the Quaternary Period. (b) Favorable conditions. (1) Site conditions that permit the emplacement of waste at a depth of at least 300 meters below the directly overlying ground surface. (2) A geologic setting where the nature and rates of the erosional processes that have been operating during the Quaternary Period are predicted to have less than one chance in 10,000 over the next 10,000 years of leading to releases of radionuclides to the accessible environment. (3) Site conditions such that waste exhumation would not be expected to occur during the first one million years after repository closure. (c) Potentially adverse conditions. (1) A geologic setting that shows evidence of extreme erosion during the Quaternary Period. (2) A geologic setting where the nature and rates of geomorphic processes that have been operating during the Quaternary Period could, during the first 10,000 years after closure, adversely affect the ability of the geologic repository to isolate the waste. (d) Disqualifying condition. The site shall be disqualified if site conditions do not allow all portions of the underground facility to be situated at least 200 meters below the directly overlying ground surface.