PW13 Sediment Chemistry
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW203) Evaluation of the Surface Transport of NORM from Former Uranium Mines Through Sediment Core Analysis.
Willingham, M1, Smith, C1, Dolan, B1, Tissot, P1, 1 Texas A&M University Corpus Christi, Corpus Christi, Texas, USA
ABSTRACT- Over sixty open pit uranium mines were excavated in the sixties and seventies and are currently being decommissioned in an area 50 miles southeast of San Antonio, Texas. Runoffs of Naturally Occurring Radioactive Materials (NORM) from the mines can potentially enter the Nueces River Watershed via creeks located near the mines. A previous study of a stock pond located in the mining watershed indicated that 226Ra levels increased by a factor of three during the mining period between the 1960's and the 1980's before returning to pre-mining levels. Another study of sediment cores from Lake Corpus Christi, a large reservoir downstream from the mines that provides a significant amount of potable water for the city of Corpus Christi, did not indicate any increase in NORM during the mining period. The purpose of this study is to determine the extent of the NORM surface transport from selected former Uranium mines. Several sediment cores were taken from creek beds draining directly at the base of the former Rosenbrock Mine and passing near several other mines including the former Esse Mine. The presence and variation in time of the transport of NORM contaminants was studied by analyzing the core samples using a High Purity Germanium gamma ray spectroscopy. Based on these results as well as prior studies, the extent and the conditions necessary for the surface transport of NORM is estimated within the context of the South Texas Uranium mines.
Key words: Erosion, NORM, Sediments, Uranium Mine