CONCLUSIONS In order to compare results of the model to results from the actual site, certain reservations must be understood. The model constructed in the laboratory was primarily a chemical model. It could not reproduce geologic conditions of the site, the most prominent of which are fractures in the rock which can greatly accelerate or retard the flow of solutions through a stratum depending upon whether they are void or clay filled. Such geologic features contribute to the character of the site data and, in fact, may outweigh the chemical effects. For example, examination of the core indicated the presence of a clay-filled fracture at approximately 14 feet. This fracture appeared to be restricting downward flow of moisture, possibly accounting for the reduced activity below that depth in the core. Nevertheless, the model correctly predicts the large surface concentration for plutonium as well as a maximum depth of penetration of 14 feet. The latter is based on the modeling scale of 2.2 ft/cm. Our predictions for americium did not fare nearly so well. Instead of the near surface peak predicted by the model, americium was found at the site in a diffuse band near 9 feet. The danger of inferring too much from a single coring experiment ag obvious. Therefore, more corings and evaluations are planned and under way with the hope of resolving the discrepancies and confirming the predictions. Ci TRATE |}¢—HF ——>" €NaNOs+y ¢-—— H,0 ———_5 ACKNOWLEDGMENT This work was supported by the U.S. Energy Research and Development Administration, Division of Nuclear Fuel Cycle and Production. N GW a COUNTS 7 MIN X 1000 in ELUTION OF PLUTONIUM FROM LABORATORY MODEL 2 4 6 COLUMN 8 10 VOLUME l2 I4 6 Figure 5 124 125