Quarterly report of the Argonne National Laboratory Chemical Engineering Division regarding activities related to properties and handling of radioactive materials, operation of nuclear reactors, and other relevant research. This report includes studies on advanced solvent extraction techniques focused on the development of centrifugal contactors for use in Purex processes, extraction kinetics of ruthenium and zirconium in the presence of uranium, and dispersion of uranium and plutonium by fires.

To evaluate potential electrodes for molten carbonate fuel cells, we reviewed the literature pertaining to these cells and interviewed investigators working in fuel cell technology. In this critical survey, the effect of three electrode aging processes - corrosion or oxidation, sintering, and poisoning - on these potential fuel-cell electrodes is presented. It is concluded that anodes of stabilized nickel and cathodes of lithium-doped NiO are the most promising electrode materials for molten carbonate fuel cells, but that further research and development of these electrodes are needed. In particular, the effect of contaminants such as H2S and HCl on the nickel anode must be investigated, and methods to improve the physical strength and to increase the conductivity of NiO cathodes must be explored. Recommendations are given on areas of applied electrode research that should accelerate the commercialization of the molten carbonate fuel cell.

The low-cycle fatigue behavior of Type 304 stainless steel has been investigated at 593 degrees C in a dynamic vacuum of better than 1.3 x 10⁻⁶ Pa (10⁻⁸ torr). The results concerning the effects of strain range, strain rate and tensile hold time on fatigue life are presented and compared with results of similar tests performed in air and sodium environments. Under continuous symmetrical cycling, fatigue life is significantly longer in vacuum than in air; in the low strain range regime, the effect of sodium on fatigue life appears to be similar to that of vacuum. Strain rate (or frequency) strongly influences fatigue life in both air and vacuum. In compressive hold-time tests, the effect of environment on life is similar to that in a continuous-cycling test. However, tensile hold times are nearly as damaging in vacuum as in air. Thus, at least for austenitic stainless steels, the influence of the environment of fatigue life appears to depend on the loading waveshape.

Three-dimensional finite-element models for the treatment of the nonlinear, transient response of a fast breeder reactor's above-core structures are described. For purposes of treating arbitrarily large rotations, node orientations are described by unit vectors and the deformable elements are treated by a corotational formulation in which the coordinate system is embedded in the elements. Deformable elements may be connected either to nodes directly or through rigid bodies. The time integration is carried out by the Newmark beta method. These features have been incorporated to form the finite-element program SAFE/RAS (Safety Analysis by Finite Elements/Reactor Analysis and Safety Division). Computations are presented for semianalytical comparisons, simple scoping studies, and Stanford Research Institute (SRI) test comparisons.

This report describes a quasi-Eulerian method which has been incorporated into the ICECO code to study slug impact and coolant spillage problems in a fast-reactor accident. The quasi-Eulerian cells used in this method are located on the tops of the regular cells. The axial size of the quasi-Eulerian cells varies according to the gap generated at the reactor head-wall junction. Penetration holes on the cover head are modeled on the top center of the quasi-Eulerian cells. Fluid variables in these quasi-Eulerian cells also satisfy all the conservation equations. Since the boundary pressures above the quasi-Eulerian cells are determined by the movement of the moving grid, the velocity of the cover head is also included in the pressure iteration. Several examples are given to compare the results obtained by this quasi-Eulerian method with the existing experimental excursion data, as well as with the analytical and the other code solutions.

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving the components of moltencarbonate-electrolyte fuel cells operated at temperatures near 925 K.

A modified version of the LIFE-III code, LIFE-GCFR, and classical stress-analysis techniques have been used to calculate the stresses in the GCFR cladding under normal reactor operating conditions. Several types of loadings on the cladding that occur during normal operation have been considered. These include fuel-cladding mechanical interaction, thermal stresses induced by radial and axial temperature gradients, and swelling gradient-induced stresses. The combined and individual effects of these loadings, as well as the effect of creep on cladding stresses, have been assessed.

Quarterly report on the activities of the Argonne National Laboratory Materials Science Division regarding economical conversion of coal into clean and usable fuels through the use of durable materials systems. This project is designed to provide part of the materials information necessary for successful operation of coal-conversion systems.

This report discusses the development of ultrasonic testing, acoustic microscopy, dye-enhanced radiography, holographic interferometry, and infrared scanning techniques for flaw detection in silicon carbide (SiC) heat-exchanger tubing. Both preservice and in-service testing requirements are discussed. An ultrasonic boreside probe and an acoustic microscope stage have been designed for continuous monitoring of SiC tubing. Preliminary results with these acoustic systems are presented. In addition, a novel technique for detecting small surface flaws using holographic interferometry is discussed. Fracture mechanics analysis suggests that detection of flaws on the order of 100 um is necessary to assure good reliability of ceramic heat exchangers. The acoustic and holographic techniques have been shown to be capable of detecting flaws of this size. However, the sensitivity of ultrasonic flaw detection in SiC is affected by the microstructure of the component. The practical considerations involved in the use of these techniques are discussed.

A small ruby laser adapted to fire through a microscope is used to release fission gases from specific sites on a plane surface of an irradiated fuel specimen. Interaction of the focused laser pulse with the specimen surface results in a conical crater from which sampled material has been vaporized; the crater is surrounded by a heat-affected zone in which intergranular fracture and grain separation allow release of grain-boundary gases. Procedures for measuring the amount of krypton-85 released by laser heating and the volume of material from which the release occurred are presented. The data obtained may be used to obtain local krypton fission-gas concentrations and the intragranular/intergranular distribution.

The LIMBO (liquid metal boiling) code for the analysis of two-phase flow phenomena in an LMFBR reactor coolant channel is presented. The code uses a non-equilibrium, annular, two-phase flow model, which allows for slip between the phases. Furthermore, the model is intended to be valid for both quasi-steady boiling and rapid coolant voiding of the channel. The code was developed primarily for the prediction of, and the posttest analysis of, coolant-voiding behavior in the SLSF P-series in-pile safety test experiments. The program was conceived to be simple, efficient, and easy to use. It is particularly suited for parametric studies requiring many computer runs and for the evaluation of the effects of model or correlation changes that require modification of the computer program. The LIMBO code, of course, lacks the sophistication and model detail of the reactor safety codes, such as SAS, and is therefore intended to compliment these safety codes.

This document describes in detail the ongoing and planned US Test program on the mechanical properties of sodium-exposed Type 316 austenitic stainless and Fe-2 1/4 Cr-1 Mo ferritic steels. The test program is based on the Development Requirement Specifications (DRS) established by the DOE/Clinch River Breeder Reactor Project (CRBRP) Program Office, the general need for the development of LMFBR structural-design criteria established by the Nuclear Systems Materials Handbook, and the need for a fundamental understanding of materials behavior in a sodium environment, which is generic to LMFBR systems. The planned test program is an extension of work based on current knowledge of sodium chemistry and the influence of sodium purity on the mechanical properties of structural materials.

This report presents a solution method for transient, homogeneous, equilibrium, two-phase flows of a single-component fluid in one space dimension. The method combines a direct finite-difference procedure and the method of characteristics. The finite-difference procedure solves the interior points of the computing domain; the boundary information is provided by a separate procedure based on the characteristics theory. The solution procedure for boundary points requires information in addition to the physical boundary conditions. This additional information is obtained by a new procedure involving integration of characteristics in the hodograph plane.

Analytical expressions have been developed to estimate the average unavailability of an m-out-of-n (m/n, 1 less than or equal to m less than or equal to n less than or equal to 4) standby safety system of a nuclear power plant. The expressions take into account contributions made by testing, repair, equipment failure, human error, and different testing schemes. A computer code, ICARUS, has been written to incorporate these analytical equations. The code is capable of calculating the average unavailability, optimum test interval, and relative contributions of testing, repair, and random failures for any of three testing schemes. After verification of the methodology and coding in ICARUS, a typical auxiliary feed-water system of a nuclear power plant was analyzed. The results show that the failure modes associated with testing and true demands contribute considerably to the unavailability and that diesel generators are the most critical components contributing to the overall unavailability of the system.

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving the components of molten-carbonate-electrolyte fuel cells operated at temperatures near 925 K. The primary focus of this work has been the development of electrolyte structures that have good electrolyte retention and mechanical properties as well as long-term stability, and on developing methods of synthesis amendable to mass production.

Both 2F di-n-amyl-n-amylphosphonate in n-dodecane (DA(AP)-DD) and 0.77F tricaprylmethylammonium nitrate in Aromatic 100 (TCMA.NO/sub 3/-AR100) extract uranium and thorium into relatively concentrated organic solutions. Countercurrent-flow tests with each extractant have demonstrated effective uranium-thorium separations by selective stripping from the organic phase. Both extractants offer advantageous alternatives to tributylphosphate (Thorex) in reprocessing irradiated mixed ThO2-UO2 fuels. Formic acid is used for removing thorium from DA(AP)-DD; dilute HNO3 removes uranium from TCMA.NO3-AR100. Spectra of plutonium in formic acid are shown. The use of concentrated TCMA.NO3-AR100 at 50 to 65/sup 0/C avoids viscosity problems and suppresses third-phase formation. Thorium extracts into concentrated TCMA.NO/sub 3/-AR100 in greater amounts than would be predicted from stoichiometric assumptions.

A review was conducted during the period of mid-June to mid-August 1979, of the literature on spray combustion. Particular attention has been paid to theoretical and experimental work on droplet and spray combustion applicable to the use of alternate fuels, mainly liquid fuels derived from coal and shale.

Annual report of the Argonne National Laboratory Chemical Engineering Division regarding studies of nuclear waste migration in geologic media. This report discusses research regarding nuclide migration by fluid flow in rock.

This report describes ALICE, which uses an arbitrary Lagrangian-Eulerian method to analyze the response of the contaminant vessel and other solid media inside a reactor contaminant.

A system has been designed to use CPC collectors to collect solar energy and to generate steam for industrial process heat purposes. The system is divided into two loops with the collectors in the collector loop to operate a pre-heater and the collectors in the boiler loop to heat water to elevated pressures and temperatures. A flash boiler is used to throttle the heated water to steam. Two types of CPC collectors are chosen. In the collector loop the CPC collectors are fitted with concentric tube receivers. In the boiler loop the collectors employ heat pipes to transmit heat. This design is able to alleviate the scaling and plumbing problems. A fragile receiver tube can also be employed without rupture difficulties. The thermal processes in the collectors were analyzed using a computer modeling. The results were also used to develop a thermodynamic analysis of the total system. Calculations show that the design is technically feasible. The CPC collector is shown to have an efficiency that is very weakly dependent on its operating temperatures, which makes the collector particularly attractive in high temperature applications.

The quantities of krypton-85 that can be released to the environment from nuclear energy production are to be limited after 1983 by Federal regulations. Although procedures for collecting the krypton-85 released in the nuclear fuel cycle have been developed to the point that they are commercially available, procedures for terminal disposal of the collected gas are still being examined for their feasibility. In this work, the possibilities of underground disposal of krypton-85 by several techniques were evaluated. It was concluded that (1) disposal of krypton-85 as a solution in water or other solvents in deep wells would have the major disadvantages of liquid migration and the requirement of extremely large volumes of solvent; (2) disposal as bubbles entrained in cement grout injected underground presents the uncertainty of gaseous migration through permeable solid grout; (3) disposal by injection into abandoned oil fields would be favored by solubility of krypton in residual hydrocarbons, but has the disadvantages that such fields contain numerous shafts offering avenues of escape and also that the fields may be reworked in the future for their hydrocarbon residues; (4) underground retention of krypton-85 injected as a gas may be promising, given the right lithology, through entrapment in interstices …

During an unprotected undercooling accident in a liquid-metal fast breeder reactor, the motion and relocation of the molten cladding can he important because of its potentially significant effect on reactivity, blockage formation, and subsequent fuel motion. The present study analyzes the clad relocation problem1 based on a multichanneI film-flow model. The important aspects considered in the analysis are the nonuniform transverse ci1ad-melting pattern and diversions of sodium vapor flow within a subassembly. It has been shown that the motion of molten clad and subsequent blockage formations can be significantly influenced by this interconnected channel effect. Several sample cmi cu lat ions have been made in order to demonstrate these points.

A flow-sheet for the recovery of actinides from TBP-Na2CO3scrub-waste solutions has been developed, based on batch extraction data, and tested, using laboratory-scale countercurrent extraction techniques. The process, called the ARALEX process, uses 2-ethyl-1-hexanol (2-EHOH) to extract the TBP degradation products (HDBP and H/sub 2/MBP) from acidified Na2CO3scrub waste leaving the actinides in the aqueous phase. Dibutyl and monobutyl phosphoric acids are attached to the 2-EHOH molecules through hydrogen bonds, which also diminish the ability of the HDBP and H2/MBP to complex actinides. Thus all actinides remain in the aqueous raffinate. Dilute sodium hydroxide solutions can be used to back-extract the dibutyl and monobutyl phosphoric acid esters as their sodium salts. The 2-EHOH can then be recycled. After extraction of the acidified carbonate waste with 2-EHOH, the actinides may be readily extracted from the raffinate with DHDECMP or, in the case of tetra- and hexavalent actinides, with TBP. The ARALEX process can also be applied to other actinide waste streams which contain appreciable concentrations of polar organic compounds (e.g., detergents) that interfere with conventional actinide ion exchange and liquid-liquid extraction procedures.

A lithium-aluminum/iron sulfide battery which uses a molten LiCl-KCl electrolyte is presently under development at Argonne National Laboratory. The performance and lifetime of this electrochemical system depend, in part, on the ability of the electrolyte to wet the materials used as electrodes, separators, and particle retainers. For this reason contact-angle measurements were made on smooth, 100%-dense surfaces of the cell materials. In addition, electrolyte penetrability determinations were made on the porous materials actually used as cell separators and particle retainers. The results of these measurements led to techniques for completely filling porous cell components with electrolyte, suggestions for dealing with the problem of electrolyte creeping, estimates of the likelihood of electrolyte transfer from one porous component to another, and estimation of the maximum allowable vertical cell dimensions.