Erosion protection for the atlas corporation uranium mill and tailings disposal area

Through the combination of several innovative erosion control measures, the tailings pile cover for the Atlas Corporation (Atlas) uranium mill and tailings disposal area was designed to address long-term climatic, geomorphological, hydrological, and geotechnical concerns. These included the effects of a probable maximum flood, potential channel migration of the adjacent Colorado River and Moab Wash, potential rock falls and landslides, and migrating sand dunes. The erosion protection measures for the tailings pile cover include a rock armor cap, riprap protected tailings pile side slopes and drainage channels, rock aprons to minimize the potential for head cutting at the outlets of the drainage channels, toe protection against scour, a buried rock wall to protect from potential Moab Wash migration, and a self-launching apron to protect from potential Colorado River migration. This paper addresses the techniques and methods used to design and size the erosion protection riprap for the tailings pile cover and diversion channels in accordance with NRC requirements and guidelines.