At Argonne National Laboratory Research Articles

Criticality Safety Strategy and Analysis Summary for the Fuel Cycle Facility Electrorefiner at Argonne National Laboratory West

As part of the termination activities of Experimental Breeder Reactor II (EBR-II) at Argonne National Laboratory (ANL) West, the spent metallic fuel from EBR-II will be treated in the fuel cycle facility (FCF). A key component of the spent-fuel treatment process in the FCF is the electrorefiner (ER) in which the actinide metals are separated from the active metal fission products and the reactive bond sodium. In the electrorefining process, the metal fuel is anodically dissolved into a high-temperature molten salt, and refined uranium or uranium /plutonium products are deposited at cathodes. The criticality safety strategy and analysis for the ANL West FCF ER is summarized. The FCF ER operations and processes formed the basis for evaluating criticality safety and control during actinide metal fuel refining. To show criticality safety for the FCFER, the reference operating conditions for the ER had to be defined. Normal operating envelopes (NOEs) were then defined to bracket the important operating conditions. To keep the operating conditions within their NOEs, process controls were identified that can be used to regulate the actinide forms and content within the ER. A series of operational checks were developed for each operation that will verify the extent or success of an operation. The criticality analysis considered the ER operating conditions at their NOE values as the point of departure for credible and incredible failure modes. As a result of the analysis, FCFER operations were found to be safe with respect to criticality.

Characterization of a Plutonium-Bearing Zirconolite-Rich Synroc

ABSTRACTA titanate-based ceramic waste form, rich in phases structurally related to zirconolite (CaZrTi2O7), is being developed as a possible method for immobilizing excess plutonium from dismantled nuclear weapons. As part of this program, Lawrence Livermore National Laboratory (LLNL) produced several ceramics that were then characterized at Argonne National Laboratory (ANL). The plutonium-loaded ceramic was found to contain a Pu-Gd zirconolite phase but also contained plutonium titanates, Gd-polymignyte, and a series of other phases. In addition, much of the Pu was remained as PuO2-x. The Pu oxidation state in the zirconolite was determined to be mainly Pu4+, although some Pu3+was believed to be present.

Development and Testing of a Glass Waste Form for the Immobilization of Plutonium

ABSTRACTTwo alkali-tin-silicate (ATS) glasses have been prepared at Argonne National Laboratory (ANL) as part of our ongoing research in radioactive waste glass development. These glasses dissolved 5% and approximately 7% Pu. Early corrosion test results indicate that Pu-bearing ATS glass is extremely durable. The initial goal in this project concerned equally both the solubility of Pu and the durability of the ATS glasses; however, our primary emphasis has changed recently to maximizing the loading of Pu in the glass. ATS-based glasses, using Th(VI) and Ce(III) as surrogates for Pu(IV), are now being investigated to increase the solubility of Pu without substantially sacrificing the durability of the current ATS formulations. The solution data from various corrosion tests on the original Pu-containing ATS glasses are also presented.

Technological and economic potential of poly(lactic acid) and lactic acid derivatives

Lactic acid has been an intermediate-volume specialty chemical (world production ∼ 40,000 tons/yr) used in a wide range of food processing and industrial applications. Lactic acid has the potential of becoming a very large volume, commodity-chemical intermediate produced from renewable carbohydrates for use as feedstocks for biodegradable polymers, oxygenated chemicals, plant growth regulators, environmentally friendly ‘green’ solvents, and specialty chemical intermediates. The recent announcements of new development-scale plants for producing lactic acid and polymer intermediates by major U.S. companies, such as Cargill, Ecochem (DuPont/ConAgra), and Archer Daniels Midland, attest to this potential. In the past, efficient and economical technologies for the recovery and purification of lactic acid from crude fermentation broths and the conversion of lactic acid to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. The development and deployment of novel separations technologies, such as electrodialysis (ED) with bipolar membranes, extractive distillations integrated with fermentation, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The use of bipolar ED can virtually eliminate the salt or gypsum waste produced in the current lactic acid processes. Thus, the emerging technologies can use environmentally sound processes to produce environmentally useful products from lactic acid. The process economics of some of these processes and products can also be quite attractive. In this paper, the recent technical advances in lactic and polylactic acid processes are discussed. The economic potential and manufacturing cost estimates of several products and process options are presented. The technical accomplishments at Argonne National Laboratory (ANL) and the future directions of this program at ANL are discussed.

Technological and economic potential of poly(lactic acid) and lactic acid derivatives

Lactic acid has been an intermediate-volume specialty chemical (world production ∼ 40,000 tons/yr) used in a wide range of food processing and industrial applications. Lactic acid has the potential of becoming a very large volume, commodity-chemical intermediate produced from renewable carbohydrates for use as feedstocks for biodegradable polymers, oxygenated chemicals, plant growth regulators, environmentally friendly ‘green’ solvents, and specialty chemical intermediates. The recent announcements of new development-scale plants for producing lactic acid and polymer intermediates by major U.S. companies, such as Cargill, Ecochem (DuPont/ConAgra), and Archer Daniels Midland, attest to this potential. In the past, efficient and economical technologies for the recovery and purification of lactic acid from crude fermentation broths and the conversion of lactic acid to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. The development and deployment of novel separations technologies, such as electrodialysis (ED) with bipolar membranes, extractive distillations integrated with fermentation, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The use of bipolar ED can virtually eliminate the salt or gypsum waste produced in the current lactic acid processes. Thus, the emerging technologies can use environmentally sound processes to produce environmentally useful products from lactic acid. The process economics of some of these processes and products can also be quite attractive. In this paper, the recent technical advances in lactic and polyactic acid processes are discussed. The economic potential and manufacturing cost estimates of several products and process options are presented. The technical accomplishments at Argonne National Laboratory (ANL) and the future directions of this program at ANL are discussed.

Failure Analysis of Nuclear Plant Components

Analyses offailed components from nuclear power-generating stations have been conducted at Argonne National Laboratory (ANL) since 1974. The considerations involved in working with and analyzing radioactive components are reviewed here, and typical failures and the analyses performed are described.

51722 Detection sensitivity of x-ray CT imaging fof NDE of green-state ceramics : Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 28 Jul.–28 Aug. 1991), Vol. 11B, pp. 1861–1868. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1992)

Improved ceramic-processing methods that use pressure slip-casting and injection molding are being developed at Norton Advanced Ceramics, with a goal of producing reliable structural ceramics for advanced heat engines. Nondestructive evaluation (NDE) of ceramic parts at different stages of processing can provide useful diagnostic information to help improve processing techniques. For example, an evaluation of density gradients in as-cast green-body samples can be used to judge mold performance and make changes in mold design. Also, the ability to detect minute flaws (20 to 50 {mu}m), such as agglomerates, inclusions, and voids, in green-body, presintered, and densified parts is important in ensuring structural reliability of the final parts, because these flaws, above certain critical sizes, can lead to catastrophic failure. Three-dimensional microfocus X-ray computed tomography (CT) and nuclear magnetic resonance imaging (MRI) systems have been developed at Argonne National Laboratory (ANL) for application to quantitative NDE evaluation of ceramics. This paper evaluates the detection sensitivity of the ANL X-ray CT system when used to determine density gradients, inclusions, and voids in green-state Si{sub 3}N{sub 4} ceramics. A theoretical account of key system- and sample-related parameters affecting X-ray CT detection sensitivity is given, and results of experimental evaluation are presented. Density calibrationmore » phantoms and net-shape-formed tensile rods with seeded defects were used in the experimental evaluation of detection limits. 6 refs., 6 figs., 1 tab.« less

Thermal analysis of a photon shutter for APS front ends

Abstract The photon shutter is one of the critical elements on the front end of the beamlines at the Advanced Photon Source (APS) now under construction at Argonne National Laboratory (ANL). The conceptual design of the photon shutter uses an enhanced heat transfer tube developed at ANL. Due to large thermal loads on the shutter, inclined geometry is used in the design to spread the footprint of the X-ray beam. Even then, thermal loads are very critical. To address the thermal and thermomechanical issues, analytical studies have been applied to a simplified model of the shutter tube. Both closed-form solutions and ANSYS finite element analysis are conducted using both a uniform and a Gaussian heat flux. Results for maximum deflections and stresses are obtained and compared with the available stress/fatigue data for the materials proposed for the shutter design.

Vibration analysis of the photon shutter designed for the advanced photon source

Abstract The photon shutter is a critical component of the beamline front end for the 7 GeV Advanced Photon Source (APS) project, now under construction at Argonne National Laboratory (ANL). The shutter is designed to close in tens of milliseconds to absorb up to 10 kW heat load (with high heat flux). Our shutter design uses innovative enhanced heat transfer tubes to withstand the high heat load. Although designed to be lightweight and compact, the very fast movement of the shutter gives rise to concern regarding vibration and dynamic sensitivity. To guarantee long-term functionality and reliability of the shutter, the dynamic behavior should be fully studied. In this paper, the natural frequency and transient dynamic analysis for the shutter during operation are presented. Through analysis of the vibration characteristics, as well as stress and deformation, several options in design were developed and compared, including selection of materials for the shutter and structural details.

Recovering CO2 From Large− and Medium-Size Stationary Combustors

This paper summarizes the results of research conducted at Ar-gonne National Laboratory (ANL) to develop and design a novel method for the recovery of CO2 from flue gases. The basic process concept Involves the combustion of a hydrocarbon fuel using a mixture of oxygen and carbon dioxide (or CO2 and H20) rather than air as the oxidant, which results In a product stream that contains primarily CO2 and H2O. This stream Is then dried and conditioned to meet the specifications of the end user, A slip stream of CO2 (or CO2, and H20) is used as a diluent in the combustion chamberto maintain a flame temperature equivalent to the temperature that would otherwise be obtained using air as an oxidant. The cost-effectiveness of the process in recovering C02 is dependent on the scale of the operation, the type of fuel used, the cost of oxygen, and the cost of capital. The sensitivity of the cost of the recovered C02 to these variables Is discussed, and a model for estimating the cost of CO2 recovered using the ANL pro...

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In situ studies of ion irradiation effects in an electron microscope

The High-Voltage Electron Microscope (HVEM)-Accelerator Facility at Argonne National Laboratory (ANL) has been used to gain insight into the process of collapse of displacement cascades to vacancy loops in metals (Ni, Cu, Fe, Ni-Si, and Ni-Al) and the crystalline-amorphous transition produced in GaAs by ion implantation.

Recent developments in the target facilities at Argonne National Laboratory

A description is given of recent developments in the target facility at Argonne National Laboratory (ANL). Highlights include equipment upgrades which enable us to provide enhanced capabilities for support of the Argonne Heavy-Ion ATLAS Accelerator Project. Also, future plans and additional equipment acquisitions will be discussed.

Assessment of the MHD Capability in the ATHENA Code Using Data from the ALEX Facility

The ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) code is a system transient analysis code with multi-loop, multi-fluid capabilities, which is available to the fusion community at the National Magnetic Fusion Energy Computing Center (NMFECC). The work reported here assesses the ATHENA magnetohydrodynamic (MHD) pressure drop model for liquid metals flowing through a strong magnetic field. An ATHENA model was developed for two simple geometry, adiabatic test sections used in the Argonne Liquid Metal Experiment (ALEX) at Argonne National Laboratory (ANL). The pressure drops calculated by ATHENA agreed well with the experimental results from the ALEX facility.

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Neutron inelastic experiments on actinide dioxides: Search for crystal-field levels in NpO2

Early experiments at the pulsed neutron source at Argonne National Laboratory (ANL) showed that it was possible to observe crystal-field (CF) levels at energy transfers above 150 meV in UO2. More recent investigations at the UK pulsed source at Rutherford Laboratory have improved the resolution and seen a series of well-resolved peaks. Based on these measurements the CF parameters are V4=−130 meV and V6=+30 meV. Since these parameters should be independent of the precise An ion, there is interest in looking at the tetravalent oxides UO2, NpO2, and PuO2. We have now performed experiments at ANL on NpO2 at temperatures between 15 and 200 K. We find no sharp peak in the excitation spectrum up to energy transfers of about 250 meV. This result is contrary to the expected strong transition at about 53 meV using the above CF parameters in a complete intermediate coupling calculation. The observed phonon spectrum of NpO2, in comparison with that of ThO2, shows larger widths in all of the three vibrational bands above ∼30 meV, which may indicate strong interaction between CF levels with optic phonons in NpO2.

Up Close: Materials Science at Argonne National Laboratory

Basic and applied materials research at Argonne National Laboratory (ANL) is conducted by the Materials Science Division (MSD) and the Materials and Components Technology Division (MCT). Of the $30 million annual budget, $23 million comes from the U.S. Department of Energy (DOE) that funds Basic Energy Sciences (BES)-Materials Sciences, Reactor Development, Fusion Energy, Fossil Energy, and Conservation Technology. Another $5 million of the $30 million budget comes from the Nuclear Regulatory Commission and the remaining $2 million is from the Department of Defense.Representative projects in fission energy include fuel element behavior in the Advanced Breeder Reactor, fuel development for the Integral Fast Reactor, and supporting research in aqueous corrosion and in phase stability.Materials research for fusion environments includes containment materials, liquid metal compatibility, vanadium alloy development, defect production processes, radiation-induced segregation, sputtering of self-replenishing low atomic number coatings, and ultrahigh field superconductors.

Acoustic leak detection for reactor coolant systems

An acoustic leak detection (ALD) facility has been constructed at Argonne National Laboratory (ANL), and tests have begun on five laboratory-grown cracks (three fatigue cracks and two thermal-fatigue cracks) and two field-induced intergranular stress-corrosion cracks (IGSCC). The acoustic characteristics of the IGSCC were established and the minimum leak rate that is detectable at a distance of 50 cm under laboratory conditions was identified to be 0.001 gal/min for a frequency window of 300–400 kHz. Cross-correlation techniques were also demonstrated for locating leaks and distinguishing among leak types. A comparison of acoustic spectra of the two leaking IGSCC at flow rates of 0.005 gal/min revealed nearly identical signals in the frequency range from 200 to 400 kHz. Below 200 kHz, the differences in geometry between the two cracks can be reflected in a signal difference. These data suggest that geometrical effects may be less significant at frequencies above 200 kHz. It appears that leak rates may be more reliably related to acoustic signals at higher frequencies.

FELIX Construction Status and Experimental Program

FELIX (Fusion Electromagnetic Induction eXperiment) is an experimental test facility being constructed at Argonne National Laboratory (ANL) for the study of electromagnetic effects in the first wall/blanket/shield (FWBS) systems of fusion reactors. The facility design, construction status, experimental program, instrumentation, and associated computer-code comparisons are described.

A Three-Dimensional Field Program

The high-energy microtrons studied at Argonne National Laboratory (ANL) require complicated magnetic field shapes. A three-dimensional infinite-permeability magnetic field program was written to show that poles and coils can be devised to produce these fields. The program is in Hewlett-Packard 9845B BASIC, which limits the active mesh to about 30 000 points. In some problems the number of useful points can be greatly increased by placing virtual points one plane beyond the active mesh. The regular cubic mesh is described by three arrays. One is a scalar potential array, H, which is derived from ampere-turns by using current cuts. Another is an information array, I, and the third is a list, L, containing other data. This data structure is similar to the Carnegie Magnet - Program. An element from I usually contains a bit string with directions for calculating the corresponding H. However, if more data are required, then the word from I is interpreted as the address in L where the required data are stored. Parts of L can be reused when two or more points require the same data. The organization of the data is shown in Fig. 1. This organization minimizes memory requirements and makes the calculation fast for most points. The program has four parts: (1) prepare the problem description file, (2) load the starting mesh, (3) relax the mesh, and (4) output results. Preliminary results indicate that the magnet edge can be quite "hard" and suggest that the required field shapes can be produced.