Long term stability considerations in the design of erosion protection covers for uranium mill tailings sites

Disposal and stabilization of uranium mill tailings must be accomplished in accordance with U.S. Nuclear Regulatory Commission regulations such as 10 CFR Part 40 and the Environmental Protection Agency (EPA) standards as contained in 40 CFR Part 192. These regulations require uranium mill tailings piles be stabilized in a manner such that they remain stable for long periods of time with little or no reliance to be placed on active maintenance. The design of protective covers for such disposal units will be significantly affected by the selection of the design flood event and the need to prevent exposure of the waste by gully intrusion or other types of erosion. This paper discusses the regulatory requirements which must be met and the various natural phenomena that must be considered. This paper also discusses acceptable methods for designing erosion protection covers, including use of the Probable Maximum Flood (PMF) as a conservative design basis and use of stable covers to provide the required protection