JAMES WAGONER (Unversity of Idaho Moscow, ID 83843) RANDALL FIELDING (Idaho National Laboratory, Idaho Falls, ID, 83415)

The purpose of these experiments is to develop a certain extrusion process that will disperse fuel homogenously in a certain area of the extruded rod. The reason being that there will be radioactive fuel inside and these certainties will make the handling a lot easier. The purpose of these experiments is to develop a certain extrusion process that will disperse fuel homogenously in a certain area of the extruded rod. The reason being that there will be radioactive fuel inside and these certainties will make the handling a lot easier.

RERTR Foil Production. JEFFREY LARSON (Brigham Young University Provo, UT 84602) CURTIS CLARK (Idaho National Laboratory, Idaho Falls, ID, 83415)

It was our task to develop a process for making larger (> 1 inch width) low enriched UMo foils. It had already been shown that small (< 1 inch width) foils could be made. Two processes were investigated for producing these foils. The first process investigated was roll casting. In this method, metal is arc melted in a crucible and bottom poured directly onto spinning copper rollers which cool and flatten the metal into a foil. Stainless steel was substituted for UMo to test this method. Some success was achieved with this process but the yield was low, (one good foil for ten casts), due to thickness variation, holes, and crucible material contaminants. These foils would require additional cold rolling to bring them to the right size. The cold rolling caused the foils to spoon and twist due to the uneven thickness of the foils. The second process investigated was ingot casting. In this process the metal was arc melted in a crucible and bottom poured into a rectangular copper mold, producing a rectangular ingot. The ingot was cold rolled into a foil with the correct thickness. This process also substituted stainless steel for UMo and proved to be very repeatable, though, defects were found to be in some of the foils. These defects were holes, cracks, or contaminants (crucible material). A casting of U10Mo was made using this process and an acceptable ingot was formed. We have yet to cold roll an ingot of UMo. Although from earlier tests the smaller ingots of UMo rolled adequately. Both of these methods required annealing to relieve surface tension in the foils or else cracking would result. Resistance annealing proved to be an efficient way of annealing the foils. An apparatus was used to stretch the foil slightly as current was being passed through it. This apparatus would straighten and anneal the foil simultaneously. An optical pyrometer was used to ensure proper annealing temperature. This method was used with stainless steel foils and proved to be adequate. It is assumed that the UMo will anneal similar to the stainless steel. An annealing apparatus has been designed to anneal the UMo and is in the process of being built. As of now, ingot casting appears to be the most repeatable method for creating foils. Roll casting might be improved with tighter process controls such as improved temperature consistency, metal flow, cleanliness of rollers, and crucible quality.

Restructuring RELAP5-3D. JOSHUA HYKES (Pennsylvania State University University Park, PA 16802) GEORGE MESINA (Idaho National Laboratory, Idaho Falls, ID, 83415)

The RELAP5-3D source code is unstructured with many interwoven logic flow paths. By restructuring the code, it becomes easier to read and understand, which reduces the time and money required for code development, debugging, and maintenance. A structured program is comprised of blocks of code with one entry and exit point and downward logic flow. IF tests and DO loops inherently create structured code, while GOTO statements are the main cause of unstructured code. FOR_STRUCT is a commercial software package that converts unstructured FORTRAN into structured programming; it was used to restructure individual subroutines. Primarily it transforms GOTO statements, ARITHMETIC IF statements, and COMPUTED GOTO statements into IF-ELSEIF-ELSE tests and DO loops. The complexity of RELAP5-3D complicated the task. First, FOR_STRUCT cannot completely restructure all the complex coding contained in RELAP5-3D. An iterative approach of multiple FOR_STRUCT applications gave some additional improvements. Second, FOR_STRUCT cannot restructure FORTRAN 90 coding, and RELAP5-3D is partially written in FORTRAN 90. Unix scripts for pre-processing subroutines into coding that FOR_STRUCT could handle and post-processing it back into FORTRAN 90 were written. Finally, FOR_STRUCT does not have the ability to restructure the RELAP5-3D code which contains pre-compiler directives. Variations of a file were processed with different pre-compiler options switched on or off, ensuring that every block of code was restructured. Then the variations were recombined to create a completely restructured source file. Unix scripts were written to perform these tasks, as well as to make some minor formatting improvements. In total, 447 files comprising some 180,000 lines of FORTRAN code were restructured. These showed significant reduction in the number of logic jumps contained as measured by reduction in the number of GOTO statements and line labels. The average number of GOTO statements per subroutine dropped from 8.8 before restructuring to 5.3 afterwards, a reduction of 40%. The maximum number of GOTO statements in any subroutine dropped from 213 to 99, a factor of 2.1. Finally, the maximum number of statement labels dropped from 210 to 43, a factor of nearly 5. While many blocks of code remain unstructured, a much greater fraction of the code is now structured. These measurements indicate a serious reduction in degree of interweaving of logic paths.

Review and Application of Thermodynamic Data Related to Pyroprocessing. ALESSANDRA CARREON (Rice University Houston, TX 77005) MICHAEL SIMPSON (Idaho National Laboratory, Idaho Falls, ID, 83415)

Electrorefining is a pyroprocessing technique that allows for the co-recovery of actinides via electrotransport. This is a useful concept in that it permits the separation of uranium, plutonium, and minor actinides from other fission products in spent nuclear fuel. Various thermodynamic factors affect the yield of such separations, though specific conditions must first be met to expect a viable outcome. These conditions depend upon the type of species desired to obtain as deposits-usually uranium and plutonium. In order to perform the required calculations necessary to predict and model actinide deposition, thermodynamic data must be consistent and standardized for universal application. A set of data has thus been compiled and is herein compared to employ for further use in electrorefining problems. Correlations for thermodynamic data based on species-dependent properties are also of interest to further field progress.