The results of tests done using the Unsaturated Test Method are presented. These tests, done to determine the suitability of glass in a potential high-level waste repository as developed by the Nevada Nuclear Waste Storage Investigations Project, simulate conditions anticipated for the post-containment phase of the repository when only limited contact between the waste form and water is expected. The reaction of glass occurs via processes that are initiated due to glass/water vapor and glass/liquid water contact. Vapor interaction results in the initiation of an exchange process between water and the more mobile species (alkalis and boron) in the glass. The liquid reaction produces interactions similar to those seen in standard leaching tests, except due to the limited amount of water present and the presence of partially sensitized 304L stainless steel, the formation of reaction products greatly exceeds that found in MCC-1 type leach tests. The effect of sensitized stainless steel on the reaction is to enhance breakdown of the glass matrix thereby increasing the release of the transuranic elements from the glass. However, most of the plutonium and americium released is entrained by either the metal components of the test or by the reaction phases, and is not released …

Progress report of the Argonne National Laboratory's Nuclear Technology Programs, including investigations in applied physical chemistry, separation science and technology, and waste management.

Proton (¹H) nuclear magnetic resonance (NMR) imaging techniques are investigated as a means to nondestructively characterize green-state (unfired) Si{sub 3}N{sub 4} ceramic components. Spectroscopic results indicate that the organic additives used in the injection molding of ceramics behave as soft solids, with broad spectral peak widths (T₂ <0.5 ms) and moderate multicomponent spin-lattice relaxation rates (T{sub 1} ranging from 11 ms to 1 s). Because of the intrinsically different spectral characteristics of the organic additives, conventional-solution NMR imaging techniques cannot be applied to these materials. Hence, the authors developed specialized NMR imaging accessories capable of applying high magnetic field gradients in a back-projection protocol. NMR images were acquired of injection-molded test bars that had been fabricated with different mixing and molding parameters. Organic concentrations determined from the NMR images were correlated with results obtained through destructive testing. The correlation suggests that NMR imaging is a viable technique for quantifying organics in injection-molded green-state ceramics.

On August 6--10, 1990, Argonne National Laboratory hosted a Theory Institute in Automated Reasoning. The institute was organized by the Mathematics and Computer Science Division and was supported by special funding from Argonne's Physical Research Program Administration. The focus of the Institute was on the obstacles confronting the effective automation of reasoning. The objective was to lay the groundwork for formulating a theory governing the interrelationship of representation, inference rule, and strategy. Here we summarize the activities that took place during the week-long Institute. We also present an evaluation of the progress achieved-progress that includes the solution of challenge questions, the increasing use of both our database of problems and our automated reasoning program OTTER, and the discovery of new used for OTTER.

From abstract: This report "presents PHREEQE, a Fortran IV computer program designed to mode1 geochemical reactions and calculate pH, redox potential, and mass transfer as a function of reaction progress. "It contains tables and other figures.