Toward petascale computing in geosciences: application to the Hanford 300 area

Modeling uranium transport at the Hanford 300 Area presents new challenges for high performance computing. A field-scale three-dimensional domain with an hourly fluctuating Columbia river stage coupled to flow in highly permeable sediments results in fast groundwater flow rates requiring small time steps. In this work, high-performance computing has been applied to simulate variably saturated groundwater flow and tracer transport at the 300 Area using PFLOTRAN. Simulation results are presented for discretizations up to 10.8 million degrees of freedom, while PFLOTRAN performance was assessed on up to one billion degrees of freedom and 12,000 processor cores on Jaguar, the Cray XT4 supercomputer at ORNL