2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 3
Presentation Time: 8:35 AM

RADIOACTIVE MATTER FROM UNDERGROUND NUCLEAR WASTE SITES, INCLUDING YUCCA MOUNTAIN, NEVADA, MIGRATES UPWARD BY HYDROTHERMAL AND INTRUSIVE PROCESSES


DICKSON, F.W., Geological Sciences and Engineering, Uniiversity of Nevada Reno, Reno, NV 89557, fdickson@mines.unr.edu

Nuclear waste buried underground would return to surface by geological mechanisms, seriously threatening life. Mobile matter forms in systems that contain energy in excess of equilibrium levels, and where heat is not dispersed smoothly by conduction. Dickson (2003) pointed out the dangers of lost containment and migration of radioactive matter to the surface. Transport of matter and energy is facilitated by liquids, of magmas and in liquid-rock systems that convectively overturn *(Dickson, 2005). Energy released from underground waste affects shallow groundwaters similarly to input of volcanic heat, by generating hydrothermal convection cells that reach the surface as hot springs. Bodies of liquid silicates (magmas) move upward physically as floating diapirs, and chemically as reaction cells (Dickson, 2000) that replace cover rocks. Disequilibrium processes of Ilya Prigogine (1997) proceed along earth's gradients of temperature, pressure, composition and gravity. Natural liquids obey laws of solution chemistry (Dickson and Hsu, 2000). Liquid coatings on minerals of heated rocks result from partial dissolution of fugitive fractions well below melting conditions. Properties of rock-fluid systems are strongly affected. Coatings provide paths for reactions and enhance rates. Interstitial liquids lower bulk viscosities that cause convective overturn in mantle and crust. Coatings coalesce into magmatic bodies that move upward. Reaction cells cycle liquefaction energies between endothermic dissolution of cover rocks at tops with exothermic precipitation of minerals at bases, with freed energies moving upward by convective overturn in central liquids. *Dickson, F. W., 2005, Role of liquids in disequilibrium processes of earth and replacement in the Papoose Flat pluton, California, in Rhoden, H. N., Steininger, R. C., and Vikre, P. G., eds., Geological Society of Nevada Symposium 2005: Window to the World, Reno, NV, May 2005, p. 161-178.