A thorough review is provided on nuclear fuels for steady-state thermal research and test reactors. The review was conducted to provide a documented data base in support of recent advances in research and test reactor fuel development, manufacture, and demonstration in response to current US policy on availability of enriched uranium. The review covers current fabrication practice, fabrication development efforts, irradiation performance, and properties affecting fuel utilization, including thermal conductivity, specific heat, density, thermal expansion, corrosion, phase stability, mechanical properties, and fission-product release. The emphasis is on US activities, but major work in Europe and elsewhere is included. The standard fuel types discussed are the U-Al alloy, UZrH/sub x/, and UO2 rod fuels. Among new fuels, those given major emphasis include H3Si-Al dispersion and UO2 caramel plate fuels.

A framework for a method to predict fluid-elastic instability in heat exchanger tube bundles is presented. The method relies on a three-dimensional, cylindrical coordinate, thermal-hydraulic analysis code to obtain a representation of the three-dimensional flow distribution within the heat exchanger. With this information, local cross-flow velocities corresponding to each tube in the exchanger are obtained by interpolation and resultant cross-flow velocity distributions are computed. With a knowledge of the vibration mode shapes and frequencies, reduced effective cross-flow velocities are then computed for each tube. A comparison with experimental results shows excellent agreement: the tubes with high values of predicted reduced effective cross-flow velocity are the same tubes that first experience fluid-elastic instability in the flow tests and vibrate most violently; also, the simulation correctly predicts that the tubes directly exposed to the flow from the inlet nozzle have a low potential for fluid-elastic instability. Very good agreement is also shown in the comparison of the predicted reduced effective cross-flow velocities with the critical value obtained from a design guide. In summary, the feasibility of developing a heat exchanger tube vibration prediction method, based on a computer simulation of flow distribution, is demonstrated. Such a method would have immediate application in …

This report discusses the design, production, and evaluation of clad uranium-alloy targets that function as spallation neutron sources in the ZING-P' and IPNS-I facilities with a pulsed (10 to 30 Hz), 500-MeV proton beam. The methodology and results of theoretical nuclear-particle transport, heat transport, and stress analyses that were used in the development of a design for the targets are described. The production of a zirconium-clad uranium-alloy cylinder for ZING-P' and Zircaloy-2-clad uranium-alloy discs for IPNS-I is discussed with particular attention to the procedural details. The theoretical analyses were verified by measuring the thermal and mechanical response of the clad uranium under conditions designed to simulate the operations of the pulsed-neutron sources.

Compiled proceedings of the fifth Symposium on Instrumentation and Control for Fossil-Energy Processes, covering process control involved in the conversion of fossil fuels into synthetic fuels.

A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity rubidium chloride product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant rubidium chloride is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.

This paper describes a computational method for improving the accuracy of a given singular value and its associated left and right singular vectors. The method is analogous to iterative improvement for the solution of linear systems. That is, by means of a low-precision computation, an iterative algorithm is applied to increase the accuracy of the singular value and vectors; extended precision computations are used in the residual calculation. The method is related to Newton's Method applied to the singular value problem and inverse iteration for the eigenvalue problem.

This report describes how solar system tanks fail to stratify, a new solar system control strategy that allows stratification, a one-dimensional analytical model of thermally stratified tanks, experimental measurement of thermal stratification in tanks, correlation of experimental measurements with empirical constants in the analytical model, and a procedure for designing thermally stratified tanks. Failure to stratify is explained in terms of the critical Richardson number. The key to the new control strategy is to avoid a Richardson number that decreases during solar collection. The analytical model is an approximate solution based on assumptions that (1) the solution is a function of elevation and time, only, (2) plug flow exists, (3) flow rate is constant, (4) the cross-sectional areas of the tank and tank wall are constant, (5) there is a step change of inlet temperature, (6) there is heat transfer between the tank wall and the water, and (7) thermal losses from the tank are negligible. Empirical constants in the theory are determined by adjusting them until the best least-squares fit with experimental data is obtained and correlating the constants with the Fourier and Richardson numbers. The new control strategy allows tanks to stratify and reduces the average collector operating …

The application of neutron activation analysis to the determination of element release from simulated nuclear waste forms during leaching is described for several different glasses. Potential neutron irradiation effects are discussed, and it is shown, by a series of leach tests on activated and non-activated glass samples, that neutron irradiation has no discernible effect on the release of silicon and cesium during leaching. The radioisotopes best suited for analysis with this method and their associated detection limits are identified, and the method's applicability to waste forms other than glass is discussed.

This evaluation of radiation effects in silicate glasses caused by ionization is based on our own investigations, on material collected in our files (reports, articles, and notes), and on a computer literature search through recent issues of Physics Abstracts and Chemical Abstracts (and the apparently pertinent references which appeared). Some of the recent results, available heretofore only in internal correspondence, are presented in some detail. It is concluded that research into the behavior of silicate glasses generally will be required before the specific effects in the radioactive waste storage glasses can be properly understood and evaluated. Two particular neglected areas of investigation are targeted for immediate concern: a kinetic analysis of annealing data and the acquisition of data on effects of irradiation at controlled elevated temperatures.

Newton's method plays a central role in the development of numerical techniques for optimization. In fact, most of the current practical methods for optimization can be viewed as variations on Newton's method. It is therefore important to understand Newton's method as an algorithm in its own right and as a key introduction to the most recent ideas in this area. One of the aims of this expository paper is to present and analyze two main approaches to Newton's method for unconstrained minimization: the line search approach and the trust region approach. The other aim is to present some of the recent developments in the optimization field which are related to Newton's method. In particular, we explore several variations on Newton's method which are appropriate for large scale problems, and we also show how quasi-Newton methods can be derived quite naturally from Newton's method.

The use of radiotracer spiking as a method of measuring the leaching from simulated nuclear-waste glass is shown to give results comparable with other analytical detection methods. The leaching behavior of strontium-85, ruthenium-106, barium-133, cesium-137, cerium-141, europium-152, and other isotopes is measured for several defense waste glasses. These tests show that radiotracer spiking is a sensitive, multi-element technique that can provide leaching data, for actual waste elements, that are difficult to obtain by other methods. Additionally, a detailed procedure is described that allows spiked glass to be prepared with a suitable distribution of radionuclides.

Aging of simulated nuclear waste glass by contact with a controlled-temperature, humid atmosphere results in the formation of a double hydration layer penetrating the glass, as well as the formation of minerals on the glass surface. The hydration process can be described by Arrhenius behavior between 120 and 240 C. Results suggest that simulated aging reactions are necessary for demonstrating that nuclear waste forms can meet projected Nuclear Regulatory Commission regulations.

This physics assessment is based on roughly 300 control rod worth measurements in ZPPR from 1972 to 1981. All ZPPR assemblies simulated mixed-oxide LMFBRs, representing sizes of 350, 700, and 900 MWe. Control rod worth measurements included single rods, various combinations of rods, and tantalum and europium rods. Additional measurements studied variations in B4C enrichment, rod interaction effects, variations in rod geometry, neutron streaming in sodium-filled channels, and axial worth profiles. Analyses were done with design-equivalent methods, using ENDF/B Version IV data. Some computations for the sensitivities to approximations in the methods have been included. Comparisons of these analyses with the experiments have allowed the status of control rod physics in the US to be clearly defined.

The U-Al-Si system was investigated in the composition range from U to U-80 at.% Al to U-75 at.% Si. More than 260 binary and ternary alloys were arc melted and studied by metallographic and x-ray powder diffraction techniques, in the as-cast condition and after thermal treatment at temperatures ranging from 700 to 1040 C. One or possibly two ternary compounds of undetermined crystal structure exist at or near U2AlSi2 The binary silicides U3Si, U3Si2, and USi can dissolve only small amounts of Al in solid solution, but the higher silicides U3Si5, USi2-x, and USi/sub 3/ dissolve increasingly larger amounts of Al. Of the three binary aluminides, UAl2 can dissolve more than 12 at.% Si in solid solution. UAl3 forms a continuous solid solution with USi3, and UAl4 is not present in alloys containing more than 3 at.% Si.

Rising interest in the nuclear physics community in a GeV C.W. electron accelerator reflects the growing importance of high-resolution short-range nuclear physics to future advances in the field. In this report major current problems are reviewed and the details of prospective measurements which could be made with a GeV C.W. electron facility are discussed, together with their impact on an understanding of nuclear forces and the structure of nuclear matter. The microtron accelerator has been chosen as the technology to generate the electron beams required for the research discussed because of the advantages of superior beam quality, low capital and operating cost and capability of furnishing beams of several energies and intensities simultaneously. A complete technical description of the conceptual design for a 2 GeV double-sided C.W. electron microtron is presented. The accelerator can furnish three beams with independently controlled energy and intensity. The maximum current per beam is 100 mircoamps. Although the precise objective for maximum beam energy is still a subject of debate, the design developed in this study provides the base technology for microtron accelerators at higher energies (2 to 6 GeV) using multi-sided geometries.

An automated accountability system for special nuclear materials (SNM) is under development at Argonne National Laboratory-West. Phase I of the development effort has established the following basic features of the system: a unique file organization allows rapid updating or retrieval of the status of various SNM, based on "batch numbers," storage location, serial number, or other attributes. Access to the program is controlled by an interactive user interface that can be easily understood by operators who have had no prior background in electronic data processing. Extensive use of structured programming techniques make the software package easy to understand and to modify for specific applications. All routines are written in FORTRAN.

This report proposes six extensions to ANS PL/I, which is being revised by the American National Standards Committee X3J1. The new features include environmental enquiry functions, generalization of restricted expressions (compile-time expressions), liberalization of the contexts of restricted expressions, a named-literal declaration type, explicit precision specification for constants, and a pragmatic statement for expressing conditions that an implementation must satisfy for acceptable compilation. Used together, these features will give numerical analysts access to properties of an implementation's floating-point arithmetic in exactly the ways required to ease the burden of tailoring a program's precision specifications to new environments. In many cases it will be possible to write PL/I programs that are completely self-adapting to their host environment. Effective definition of the environmental enquiry functions will require the incorporation of an explicitly parameterized model of floating-point arithmetic. If such a model is integrated into the Standard, numerical analysts will be able to state and prove theorems about their programs' error bounds by appealing directly to the Standard.

The design, development, and use of the software package called LINPACK, a collection of subroutines to solve various systems of simultaneous linear algebraic equations are described. The package has been designed to be machine-independent and fully portable and to run efficiently in many operating environments.

An analysis of the transient swelling rate of oxide fuel, based on fission-gas bubble conditions calculated with the FRAS3 code, has been developed and implemented in the code. The need for this capability arises in the coupling of the FRAS3 fission-gas analysis code to the FPIN fuel-pin mechanics code. An efficient means of closely coupling the calculations of swelling strains and stresses between the modules is required. The present analysis provides parameters that allow the FPIN calculation to proceed through a fairly large time step, using estimated swelling rates, to calculate the stresses. These stress values can then be applied in the FRAS3 detailed calculation to refine the swelling calculation, and to provide new values for the parameters to estimate the swelling in the next time step. The swelling rates were calculated for two representative transients and used to estimate swelling over a short time period for various stress levels.

In many nonlinear problems it is necessary to estimate the Jacobian matrix of a nonlinear mapping F. In large scale problems the Jacobian of F is usually sparse, and then estimation by differences is attractive because the number of differences can be small compared to the dimension of the problem. For example, if the Jacobian matrix is banded then the number of differences needed to estimate the Jacobian matrix is, at most, the width of the band. In this paper we describe a set of subroutines whose purpose is to estimate the Jacobian matrix of a mapping F with the least possible number of function evaluations.

This report discuses results of an experimental program to characterize the fragments generated when brittle glasses and cermaics are impacted.

This assessment seeks (1) to determine the most probable chemical compounds formed between fission products and actinides in urania fuels under normal and accident conditions and (2) to identify gaps in knowledge of these fission-product compounds. The ultimate goal of this effort is to develop predictive capability about the behavior of fission products under normal and accident conditions. The relevant thermochemical data have been organized by compound type, the chemical stability of resultant compounds determined, and data uncertainty evaluated. The assessment focused on fission-product and actinide oxides, halides, tellurides, and hydroxides. Free energy equations are given for those compounds for which data were available.

A programming methodology based on schema transformations is presented. Such an approach is a logical outcome of recent developments in program manipulating systems. Concurrent development of algorithms and their proofs of correctness is a significant feature of the proposed methodology. As the development process begins with an abstract schema, it is often possible to derive several related end algorithms in a single development process. This has implications in both the economics of software development and the understanding and teaching of algorithms. The initial schematic specification (a skeleton algorithm schema), the intermediate and final algorithm schemata are all expressed in Darlington's first-order recursion equation language exploiting set-theoretic constructs. A set of transformation rules together with a set of reduction rules for set expressions is then used to successively transform the schematic specification into different algorithm schemata. Most of the transformations are applications of a small number of common rewriting rules.

The formulation needed for the conductance of heat by means of explicit integration is presented. The implementation of these expressions into a transient structural code, which is also based on explicit temporal integration, is described. Comparisons of theoretical results with code predictions are given both for one-dimensional and two-dimensional problems. The coupled thermal and structural solution of a concrete crucible, when subjected to a sudden temperature increase, shows the history of cracking. The extent of cracking is compared with experimental data.