[en] For more than three decades a National program has been in progress to develop the necessary research for disposal of wastes from nuclear energy used in electric power production, defense and energy research and development. The essence of the National effort is to predict with the highest accuracy the performance of a repository to constrain the quantity of waste material which might enter our ambient ground waters. Numerical simulation of geochemical processes such as dissolution of a waste radionuclide is the only viable approach for predicting the performance of a repository such as salt or tuff for 10,000 to 100,000 years. Computer codes using consistent thermodynamic property values are being developed for this purpose. A critical need in prediction is basic thermodynamic data on radionuclides and other geologic materials, with special emphasis on the quality of the resulting data base. It is understood that this data base must be consistent. A number of data bases of thermodynamic property values are currently available to researchers interested in the behavior of elements present in radioactive waste. The design and scope of these compilations depend strongly on the intended use of their associated data management systems. The data management system described in this paper is intended for use in sensitivity analysis and studies designed to critically assess the performance of the disposal sites. This system facilitates management of computerized therodynamic tables. 49 refs