A history of the early use of the Monte Carlo method is presented.

The US Department of Energy has established an organizational structure that assures the quality of key data identified as being important to the licensing of a nuclear waste repository by the US Nuclear Regulatory Commission. The Materials Characterization Center collects and/or develops the test methods needed to obtain the data, and acts as a clearinghouse for all data obtained by the methods, regardless of source. The Materials Review Board reviews both test methods and test data submitted to it, and approves them if they meet the rigorous criteria and standards that have been established. The appearance of test methods and test data in the Nuclear Waste Materials Handbook is evidence that the material has undergone intensive review and can be used with confidence within the bounds of the application specified. The principal use of the Handbook is in the repository licensing process.

To study the reaction of water vapor with uranium, we have exposed clean liquid uranium surfaces to H/sub 2/O under UHV conditions. We have measured the surface concentration of oxygen as a function of exposure, and determined the maximum attainable surface oxygen concentration X/sub 0//sup s/ as a function of temperature. We have used these measurements to estimate, close to the melting point, the solubility of oxygen (X/sub 0//sup b/, < 10/sup -4/) and its surface segregation coefficient ..beta../sup s/(> 10/sup 3/). 8 refs., 5 figs., 1 tab.