The following is the abstract for a paper presented at the
Fall 1995 Meeting of the American Geophysical Union.
A Comparative Subsurface Transport Analysis for Radioactive
Waste Disposal at Various DOE Sites*
J. D. Tauxe, D. W. Lee, J. C. Wang, and G. P. Zimmerman
Oak Ridge National Laboratory, Oak Ridge, TN 37831
423-574-5348
Several sites within the Department of Energy (DOE) complex are
candidates for disposal of mixed low-level radioactive waste. To aid in
making decisions about acceptance of various radionuclides, a comparative
screening analysis of environmental transport was performed. This
Performance Evaluation (PE) employed a suite of simple analytical models
for the source term, hydrogeologic transport, and dose, coupled with site-
specific parameters, to estimate the amount of each radionuclide in the
waste form corresponding to an acceptable drinking water dose limit at a
downstream compliance point. Using this objective comparison of transport
behavior, a series of permissible waste limits was developed for 58
radionuclides at several sites in the DOE complex.
The PE calculations are a series of one-dimensional, steady-state, analytical
models, constructed and refined to capture the dominant environmental
transport phenomena associated with a particular site. Peak concentrations
are estimated at various key points along the transport path. Changes in
concentration between these points are expressed as concentration
reduction factors (CRFs) which are compared between sites. Major
contributors to the CRFs are chemical partitioning, dilution, and
radioactive decay during retarded transport.
Where available, the PE results were compared to those of a more
comprehensive Performance Assessment (PA), which generally involves complex
multi-dimensional discretized numerical simulations. The results of the PE
and PA methods applied to sites with PAs are generally within one order of
magnitude of each other, which demonstrates that the PE method has value
as both a screening and predictive tool. The comparison of PE results
between sites demonstrates that environmental transport is most important
in establishing waste limits for sites with hydrogeologic characteristics that
promote rapid transport.
*This research was supported by the U S Department of Energy under Contract No.
DE-AC05-84OR-21400 with Lockheed Martin Energy Systems, Inc.
reference for this paper:
Tauxe, J.D., D.W. Lee, J.C. Wang, and G.P. Zimmerman, "A Comparative
Subsurface Transport Analysis for Radioactive Waste Disposal at Various
DOE Sites", 1995 Fall Meeting of the American Geophysical Union, San
Francisco, California, December 11-15, 1995