Annual report of activities of the Argonne National Laboratory Physics Division, including research at ATLAS, medium-energy nuclear physics and weak interactions, theoretical nuclear physics, and atomic and molecular physics.

Progress report of the Argonne National Laboratory's Nuclear Technology Programs, including R&D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management.

The COMMIX-1AR/P computer code is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-1A to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a k-{var epsilon} model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the code to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The basic equations, underlying assumptions, and solution techniques are presented for the entire computer code, covering both old and new features.

Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and …

By means of the unsteady-flow theory and a bilinear mathematical model, a theoretical study was conducted of the chaotic dynamics associated with the fluid-elastic instability of loosely supported tubes. Calculations were performed for the RMS of tube displacement, bifurcation diagram, phase portrait, power spectral density, and Poincare map. Analytical results show the existence of chaotic, quasi-periodic, and periodic regions when flow velocity exceeds a threshold value.

In this study, we developed a coupled model of wind-induced vibration of a stack, based on an unsteady-flow theory and nonlinear dynamics of the stack's heavy elastic suspended cables. Numerical analysis was performed to identify excitation mechanisms. The stack was found to be excited by vortex shedding. Once lock-in resonance occurred, the cables were excited by the transverse motion of the stack. Large-amplitude oscillations of the cables were due to parametric resonance. Appropriate techniques have been proposed to alleviate the vibration problem.

The aqueous biphasic extraction (ABE) process for soil decontamination involves the selective partitioning of solutes and fine particulates between two immiscible aqueous phases. The biphase system is generated by the appropriate combination of a water-soluble polymer (e.g., polyethylene glycol) with an inorganic salt (e.g., sodium carbonate). Selective partitioning results in 99 to 99.5% of the soil being recovered in the cleaned-soil fraction, while only 0.5 to 1% is recovered in the contaminant concentrate. The ABE process is best suited to the recovery of ultrafine, refractory material from the silt and clay fractions of soils. During continuous countercurrent extraction tests with soil samples from the Fernald Environmental Management Project site (Fernald, OH), particulate thorium was extracted and concentrated between 6- and 16-fold, while the uranium concentration was reduced from about 500 mg/kg to about 77 mg/kg. Carbonate leaching alone was able to reduce the uranium concentration only to 146 mg/kg. Preliminary estimates for treatment costs are approximately $160 per ton of dry soil. A detailed flowsheet of the ABE process is provided.

A series of polymer-based extraction systems, based on the use of polyethylene glycols (PEGs) or polypropylene glycols (PPGs), was demonstrated to be capable of selective extraction and recovery of long-lived radionuclides, such as Tc-99 and I-129, from Hanford SY-101 tank waste, neutralized current acid waste, and single-shell tank waste simulants. During the extraction process, anionic species like TcO₄⁻ and I⁻ are selectively transferred to the less dense PEG-rich aqueous phase. The partition coefficients for a wide range of inorganic cations and anions, such as sodium, potassium, aluminum, nitrate, nitrite, and carbonate, are all less than one. The partition coefficients for pertechnetate ranged from 12 to 50, depending on the choice of waste simulant and temperature. The partition coefficient for iodide was about 5, while that of iodate was about 0.25. Irradiation of the PEG phase with gamma-ray doses up to 20 Mrad had no detectable effect on the partition coefficients. The most selective extraction systems examined were those based on PPGs, which exhibited separation factors in excess of 3000 between TcO₄⁻ and NO₃⁻/NO₂⁻. An advantage of the PPG-based system is minimization of secondary waste production. These studies also highlighted the need for exercising great care in extrapolating the partitioning behavior …

Most casting defects occur during initial pouring and therefore the design of the running system, which guides the metal from the ladle into the mold, is crucial. Traditionally, the running system and mold filling are designed by trial and error, which is tedious, time consuming, and expensive. The uncertainties that remain can be overcome by a computer simulation that demonstrates the actual process of mold filling and subsequent solidification. Computer simulation of various processes has become more and more common in recent years. The cost-effectiveness of making flawless castings has made the foundry worker more aware of the process of mold filling, identification of hot spots, etc. The macroscopic Casting Process Simulator (CaPS) software combines heat transfer and fluid flow aspects and can describe a variety of solidification aspects, including mold filling. CaPS is a two-dimensional time-dependent computer code involving a finite-volume formulation for the mass, momentum. and energy equations. CaPS has the following characteristics. CaPS uses the PATRAN geometric modeling package for constructing the geometry, generating a neutral file consisting of a list of named components, and post-processing of the simulation results; building the geometry independently of the mesh is a time-saving procedure. A structured mesh generator of structured …

This report discusses the results of the environmental protection program at Argonne National Laboratory-East (ANL) for 1990. To evaluate the effects of ANL operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the ANL site were analyzed and compared to applicable guidelines and standards.

Theoretical and experimental work was undertaken to explore the use of the Argonne design centrifugal contactor as a concentrating device for metal ions in solutions such as transuranic-containing waste streams and contaminated groundwater. First, the theoretical basis for operating the contactor as a concentrator was developed. Then, the ability of the contactor to act as a concentrating device was experimentally demonstrated with neodymium over a wide range of organic-to-aqueous (O/A) flow ratios (0.01 to 33). These data were also used to derive a correlation for the effect of O/A flow ratio on extraction efficiency.

Oxidation of copper and electronic transport in thermally grown large-grain poly-crystals of non-stoichiometric copper oxides were studied at elevated temperatures. Thermogravimetric copper oxidation was studied in air and oxygen at temperatures between 350 and 100 C. From the temperature-dependence of oxidation rates, three different processes can be identified for the oxidation of copper: bulk diffusion, grain-boundary diffusion, and surface control with whisker growth; these occur at high, intermediate, and low temperatures, respectively. Electrical conductivity measurements as a function of temperature (350 - 1134 C) and pO2 (10(sup⁻⁸-1.0 atm) indicated intrinsic electronic conduction in CuO over the entire range of conditions. Electronic behavior of non-stoichiometric Cu(sub 2)O indicates that the charge defects are doubly ionized oxygen interstitials and holes. The calculated enthalpy of formation of oxygen ((Delta)H(sub O(sub 2))) and the hole conduction energy (E(sub H)) at constant composition for non-stoichiometric Cu2O are 2.0 (plus minus) 0.2 eV and 0.82 (plus minus) 0.02 eV, respectively.

A number of situations where it has been claimed that moderate radiation doses cause leukemia or other cancers are carefully reviewed. We look at cases in the United States, Great Britain, and the Soviet Union. Usually it can be demonstrated that there is an alternative, more probable, explanation for the effect seen. In several cases the authors of the papers have fallen into statistical traps. The most frequent is a posteriori selection of cohort boundaries in both space and time: a trap illustrated dramatically by Feynman. The next most common trap is to arbitrarily select one out of many ways of looking at the data, against which we were warned by Tippett. Several cohorts are compared with respect to the number of persons at risk, average dose, and the number of cancers expected. Of these, only the cohort of A-bomb survivors in Japan and the recently unclassified data on the very large occupational doses for early Soviet nuclear workers at Chelyabinsk provide evidence of clearly visible excess cancers.

Directed Technologies, Inc. has previously submitted a detailed technical assessment and concept design for a mid-size, five-passenger fuel cell electric vehicle (FCEV), under contract to Argonne National Laboratory. As a supplement to that contract, DTI has reviewed the literature and conducted a preliminary evaluation of two energy carriers for the FCEV: hydrogen and methanol. This report compares the estimated fuel efficiency, cost of producing and delivering the fuel, and the resultant life cycle costs of the FCEV when fueled directly by hydrogen and when fueled by methanol with on-board reforming to produce the required hydrogen-rich gas for the fuel cell. This work will be supplemented and expanded under the Ford contract with the Department of Energy to develop the FCEV and its fuel infrastructure.

Improving Pollution Prevention and Waste Minimization Program (PP/WMIN) technologies, actions, and culture could be an important cost-cutting step for the US Department of Energy (DOE). Communicating ideas, concepts, process changes, and achievements is essential for the success of this program. The need to openly communicate ideas and concepts in a cost-effective manner is essential in an organization that has such diverse components as research and development, weapons production, and power generation. This approach is in contrast to the historic DOE culture developed within the cold war period in which compartmentalization, independence, and secrecy were stressed. DOE has now recognized that for any pollution prevention program to be successful, the many diverse elements of the organization must share information. Avenues for such information exchange are examined in this report.

Annual report of the Ion Replacement Electrorefining Program at Aronne National Laboratory describing their research and activities. There are three key accomplishments highlighted for the year: (1) identification of a suitable sodium(beta){double_prime}-alumina/molten salt electrolyte system that functions reproducibly at 723 K, (2) actual separation of dysprosium and lanthanum in experiments, and (3) the identification of a metal alloy, Li{sub x}Sb, as an alternative ion replacement electrode.

A set of experiments, based on the application of the Unsaturated Test method to the reaction of uranium dioxide with EJ-13 water, has been conducted over a period of 182.5 weeks. One half of the experiments have been terminated, while one half are still ongoing. Solutions that have dripped from uranium dioxide specimens have been analyzed for all experiments, while the reacted uranium dioxide surfaces have been examined for only the terminated experiments. A pulse of uranium release from the uranium dioxide solid, in conjunction with the formation of dehydrated schoepite on the surface of the uranium dioxide, was observed during the 39- to 96-week period. Thereafter, the uranium release decreased and a second set of secondary phases was observed. The latter phases incorporate cations from the EJ-13 water and include boltwoodite, uranophane, sklodowskite, compreignacite, and schoepite. The experiments are being continued to monitor for additional changes in solution composition and secondary phase formation, and have now reached the 319-week period.