This report details the numerical predictions undertaken by Dames and Moore for Rockwell Hanford Operations' Basalt Waste Isolation Project. Predictions are made for the temperatures, stresses, strains and displacements in the basalt around Full-Scale Heater Tests No. 1 and No. 2 at the Near-Surface Test Facility using the finite element code DAMSWEL. The rock around the main heaters was modeled using an axisymmetric idealization in which deformational properties were transversely isotropic with a bilinear stress/strain relationship which was independent of temperature. The selection of the input parameters represents an engineering assessment of their values based on the results of laboratory tests and in situ measurements. The predictive modeling analysis, using the best information available as of April 1980, was completed prior to test startup. Additional information on geology, geological characterization, rock-mass characterization, laboratory properties, and field properties of basalt is being acquired on a regular basis as part of the overall Near-Surface Test Facility test program. An assessment of the effect of additions to the data base upon the predictive modeling and test analysis shall be made on a periodic basis.