. * . IOFI ORNLP 1431 Er mt ISO . . MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS -1963 - --- LEGAL NOTICE This report was prepared as an account of Government sponsored work. Neither the United States, nor the Commission, nor any person acting on behalf of the Commission: A. Makes any warranty or representa- tion, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, appa- ratus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of any information, apparatus, method, or process disclosed in this report. As used in the above, “person acting on behalf of the Commission” includes any em- ployee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, any information pursuant to his employ- ment or contract with the Commission, or his employment with such contractor. ORNV-P-43/ MSDS ORXL - MEC - OFFICIAL SM-67/25 ONF-650803 ORNI - ACC - OFFICIAL JUL 20 1965 - LEGAL NOTICE - TUI report mo prepared an account of Covonmuot sponsored work. Noltbar the United moins, vor a counslon, Par vay porn acung on behall of the COGNssion: A. Kakes my warranty or noproucaution, expresand or implied, with respect to the accu- racy, complete, or imahele.. of the labor mation contained in the report, or what the wae ol may information, opuntu, molbord, or procwe dikeloond in de report may not lalringe printly oned rus; or D. Aamun... way llahtuums will roopact to the won al, or for dames roouus from the um of way wkruation, appunto, method, or pocos declared laws report. Ao word in the abova, "person acting as baball of the Counseln" includes way in- pion.. or contractar of the Contactos or upoyo of much contractor, to the extent that much smploys or contractor of the Counaslon, or employs of much contraclor preparos, disanimales, or provide acolo, may taformation pursuant to Vo saplogni or contract will the counterton, or V. employment with such contractor. MATERIALS CONTROL IN THE FABRICATION OF ENRICHED URANIUM FUELS* . Roy G. Cardwell, Jr. Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, Tennessee, USA ABSTRACT Intense activity in the field of fuel element technology at Oak Ridge National Laboratory during the past 15 years has lead to the establishment of sound process and enriched material control pro- cedures that find wide applicability in the comercial fabrication of fuel elements today. . Reliable techniques for handling .enriched fuel in alloy, dispersion, and bulk oxide form were developed and adopted as standards in the course of design and fabrication of prototypic fuel elements for startup operation of the Materials Test Reactor, Bulk Shielding or "Swimming Pool" Reactor, Army Package Power Reactor, Tower Shielding Reactor, Geneva Conference Display Reactor, High Flux Isotope Reactor, and the Experimental Gas-Cooled Reactor. The experience gained ORNL - AEC - OFFICIAL ORNI - AEC - OFFICIAL "Research sponsored by the U. S. Atomic Energy Commission under contract with the Union Carbide Corporation. PATENT CLEARANCE OBTAINED. RELEASE TO THE PUBLIC IS APPROVED. PROCEDURES ARE ON FILE IN THE Anne ORMA - AEC - OFFICIAL serves as background for this paper, which will stress material control problems and their solution during the fabrication of various types of enriched uranium fuel components. The basic objectives to be met in the design of a good materials control system are: (1) minimizing the number of material units to be accounted for, (2) designing separate records for each major fabrication step and linking these in a manner that permits isolation of differences with a minimum of effort, (3) integrating the maximum number of controls into the minimum number of records to eliminate duplication, and (4) intro- ducing a sufficient number of cross-checks into the system to ensure reliability. In every fabrication program, successful control was achieved by establishing a unit procedure in the following areas: (1) beginning materials in the as-received form, (2) fabrication of components, (3) component processing, and (4) scrap handling. Consolidation of control records into a master summary was helpful in confirming the materials inventory, evaluating the fabrication process, and preparing management reports. Establishment of sampling methods and examination of results indi- cated that multiple control is necessary to ensure proper fuel content. Mechanical adjustment and density measurement were successfully used where alloy fuel content was critical. Scrap handling had an important et'fect on the materials balance, by which fuel content was confirmed and good accountability was assured. · Records and handling procedures, includ- ing batching and physical marking methods, were formulated in a Manner that assisted the fabricator in criticality control. INTRODUCTION ORNL - AEC - OFFICIAL The scarcity, expense, and hazards of nuclear materials have often been cited as reasons for their need of proper controż and management. Equally important, however, is that technical success in the manufacture of fuel elements, particularly those containing enriched uranium, depends largely upon how well these controls are fitted to each operation. My purpose is to discuss the major control problems in the fabrica- tion of enriched uranium fuels and their solution. The material presented is based on successful controls applied during the fabrication of a 3 ORHI-TEC - OFFICIATT ORNI - AIC - OFFICIAL variety of fuel elements at the Oak Ridge National Laboratory, from the receipt and verification of starting materials to the process control sum- mary performed upon completion of the fabrication effort. Special problems in the handling of nuclear material, as opposed to conventional material, will be considered before the basic objectives in systems design are stated. After a brief description of fabricated product types, thorough discussion of enriched-uranium control procedures appli- cable to a general fabrication effort will be presented. SPECIAL CONSIDERATIONS Since enriched fuel element fabrication utilizes standard metallurgi- cal processes and equipment, the process controls are similar to those found in any metals or ceramics industry. There are end product specifi- cations regarding cherical makeup, dimensions, and strength and process concerns such as weld integrity and grain size. These and other factors must be controlled within close tolerances. In the area of materials control, however, there are few similari- ties between conventional and nuclear operations. Enriched uranium pre- sents unique control problems in handling and processing. In addition to the regular health and safety hazards, the enriched-uranium fabricator handles a material that can, if not properly controlled, seriously damage his personnel and equipment. If the uranium is highly enriched, he also risks loss of a very expensive material. Health Hazards tbindinis n . During enrichment of 235U by the gaseous diffusion process, the very active 234U is also enriched. Although external damage to the human body resulting from this alpha activity is minimal, when this material is ingested or inhaled, the hazard becomes acute. Therefore, we need to prevent it from entering the body. O DINE-AEC - OFFICIAL Criticality Control The extreme prop-irty damage and loss of life that could result from a critical accumulation of 235U in the fabrication process area demand ORNI - AEC - OFFICIAL ORN - AEC - OFFICIAL strong measures to ensure nuclear safety. Geometric control provides the best means of preventing a critical incident, but it must be reduced to practical terms and limits understood by the process technician. In addition, administrative practices must provide for a continuous surveil- lance to make certain that these limits are being adhered to. Yet, the limits must be flexible enough to permit some alteration for changes that occur in the process. Therefore the criticality expert, should evaluate both the equipment and the process in setting limits. In-Process Losses The value of highly enriched uranium requires that carefui atten- tion be given to the smallest chances for losses, unnecessary accumula- tions of in-process materials, and the possibility of mixing with materials of lower enrichment. The design of process methods and equip- ment is very important in this respect. Such procedures as filtering and sampling all exhausts, glove-box containment of powdered materials, and periodic burn recovery of filters should be established. There should be no open drains in the primary fabrication area, in which the uranium is first incorporated in non- fissile materials, and all spills should be cleaned up with dry, absorb- ent materials that can be burned for recovery. The measurement methods, including weighing, sampling, and analysis, must be of the highest quality. The accumulation of small but regular systematic errors in measurement can falsely indicate a loss of many dollars or, more seriously, obscure actual losses. The general problem of the nuclear materials manager, therefore, is complex and must be solved largely by coordination. He must design a system that will not interfere with the process objectives, yet will ensure safe handling and protection of the materials. In addition, his system must generate sufficient data to ensure product quality, statis- tically evaluate the process, and enable the necessary management reports. . ORNI - AEC - OFFICIAL OINI - AIC - Off BASIC OBJECTIVES ORNI - AIC - OSSICIAL ---- The basic objectives of a good materials control system are: (1) minimizing the number of material units to be accounted for, (2) establishing separate records for each major fabrication step and link- ing these in a manner that permits isolation of differences with a mini- mum of effort, (3) integrating the maximum number of controls into the minimum number of records to eliminate duplication, and 14, including a sufficient number of cross checks to ensure reliability. Material Units All quantity controls of enriched uranium are in terms of grams. Accounting for the materials in process 18. simplified, however, if the control basis is changed to a piece count of components of known uranium mass as they are fabricated. For example, when 400 g 235U is fully con- tained in 20 identified fuel plates, the control should be by plate rather than grain. Furthermore, wher, these 20 plates are brazed into a single fuel element, the control should shift to the element. In general, then, the number of units should be progressively reduced as the materials flow through the process. Records Enriched fuel materials are controlled for two purposes by a com- plete record around each major fabrication step. First, the fabricator can balance the quantity of uranium fuel in the starting materials of each step against the quantity in its end products to confirm the intended fuel content, evaluate any process losses, and limit the size of the process area and the number of records that must be examined should any unusual differences occur. Second, use of the final balance of, each step as the initial balance of the next step in the process links all data into a complete materials control history for the entire process and provides the basis for all evaluation of product fuel content and reporting for accountability. As previously stated the fuel manufacturer must control other general specifications of the fabricated pieces as well as the fuel C!N-AEC - OFFICIAL ORNICAEC - OFFICIAL 1 ORNt - AEC - OFFICIAL content within close tolerances. Methods for meeting such specifications include mechanical and chemical measurements and statistical evaluation of variances. Integration of Controls The records needed for each fabrication step should integrate both the general and fuel-control information into a dual-purpose form, thus reduci.ng the number of forms needed and eliminating duplications. In addition one can detect important relationships between fuel-content data and process data that might otherwise go unobserved. Cross Checks The danger of dependence on a single measurement of fuel content during any stage of the fabrication process becomes apparent when one considers the accidental variations that can occur. Balances can be off calibration, chemical analyses can be incorrect or improperly stated, and human error is always possible. To save time and expense, however, the fabricator must minimize the number of measurements and ensure himself against intolerable fuel-content deviations with sufficient reliable cross checks. These fall into four categories. ra Method and Equipment Checks. - At the Oak Ridge National Labora- tory, all balances for weighing fertile and fissile material are regu- larly calibrated against precise standards. Each calibration is recorded on a chart kept at the balance, and significant deviations dictate equip- · ment removal for repair or replacement. Random and Backup Sampling. - The fuel content of the fabricated component may also be confirmed by chemical analysis of random comco- nents. Because the component 18 destroyed, this type of sampling should be limited to the minimum number of samples from which a' sound statisti- cal evaluation can be made, and the components should be removed at the earliest possible stage of their processing. ORNL - AEC - OFFICIAL .--. ... - . .... . . ORNL - ACC - OFFICIAL+ ORNE - AIC - OFFICIAL - - During regular process sampling, an extra backup sample should be taken and held for a repeat measurement should later data fail to correlate with the original results. Statistical Evaluation. - Trends that are apparent in a regular review of all process data will often indicate control problems that. are not obvious in the day-to-day data accumulations. In one evaluation of the difference between intended and chemically analyzed content of uranium-aluminum alloy over a rather long period, we noted that new heats that included remelted aluminum-clad uranium-aluminum alloy plates usually had a higher uranium-to-aluminum ratio than intended. Investigation showed that the outer cladding material of the plates, which was of different composition than the high-purity fuel diluent material, contained small amounts' of copper that were titrated with the uranium during the analyti- cal procedure. Including an analysis for copper and adjusting the uranium analysis for the copper content corrected the situation. - - - The Material Balance. - One of the most important methods of cross checking the routine process controls is the material balance. A com- plete and thorough materials inventory is correlated with the accounting book balance at the end of a selected period. We shall discuss this in detail later. . . FABRICATED PRODUCTS . . . .. ... . .. - The types of enriched uranium fuel elements are almost as numerous and varied as the reactors now in existence. Indeed, one often has more than one specification for elements in the same reactor system. We shall, however, consider three general categories classified according to the physical form of fuel and illustrated in Fig. 1. To expand somewhat on . these categories, Table I lists a representative selection of the materials combinations now. In reactor service in the United States or manufactured by U. S. firms. memakainumanninn minimamente o travan de ORNE-AEC - OFFICIAL ORNI - AEC - OFFICIAL assistidos within the TV51310-53 Y-INYO Vidisso-)ir - INDO TABLE I NATURE OF URANIUM TUEL AND CLADDING MATERIAL IN NUCLEAR REACTORS Name and Location : Cladding Material % 2350 Enrichment Startup Fuel Material 1950 1950 A1 A2 A1 AI SS 93 93 93 20 93 93 Al SS Bulk Shielding Reactor, Oak Ridge, Tenn. Low-Intensity Training Reactor, Oak Ridge Tenn. Materials Testing Reactor, NRES, Idaho Geneva Conference Display Reactor, Geneva, Switzerland - Stationary Medlrm Power Reactor (APPR) Fort Belvoir, Va. Engineering Test Reactor, NRIS, Idaho Vallecitos Boiling Water Reactor, Pleasanton, Calif. · Shippingport Atomic Power Station, Shippingport, Pa. Oak Ridge Research Reactor, Oak Ridge, Tenn. Dresden Nuclear Power Station, Morris, 111. Puerto Rico Nuclear Center, Mayaguez, Puerto Rico Yankee Nuclear Power Station, Rowe, Mass. Consolidated Edison Thorium Reactor, Buchanan, N. Y. Hallam Nuclear Power Facillty, Hallam, Neb. . Elk River Reactor, Elk River, Minn. SENN, Gargllano River, Italy Enrico Fermi Atomic Power Plant, Lagoona Beach, Mich. High Flux Isotope Reactor, Oak Ridge, Tenni 1952 1955 1955 1957 1957 1957 1958 1959 1960 1960 1962 1962 1962 1963 1963 1965 Zrcaloy Al. Zrcaloy Al Uranium-Aluminum Alloy Ułanium-Aluminum Alloy Uranium-Aluminum Alloy UO, Dispersed in Aluminum 00, Dispersed in ss Uranium-Aluminum Alloy UO, D1.spersed in ss Uranium-Zirconium Alloy Orani im-Aluminum Alloy Pelletized vo i ,0g Dispersed in Aluminum Pelletized Uog Pelletized Thoz-UO Uranium Molybdenum Alloy Pelletized T202-00, Pelletized voz Uranium Molybdenum Alloy 0,0g Dispersed in Aluminum 5 20 3.4 93 3.6 93 2.0 0 . SS Zircaloy Zr Al ORNI - AEC - OFFICIAL ORNI - AEC - OSSICIAL CONTROL PROCEDURES ORNL - AEC - OFFICIAL • ORN! - AIC - OFFICIAL The development and fabrication of the many and varied types of fuel elements over the past 15 years at Oak Ridge National Laboratory have afforded an excellent opportunity for a parallel development and testing of materials control procedures. Reliable techniques for handl- ing enriched fuel in alloy, dispersion, and bulk oxide form were developed and, in many cases, adopted directly as standards for subse- quent commercial fabrication of these elements. In every fabrication program, successful control was achieved by establishing a unit procedure in the areas. of (1) starting material in the as-received form, (2) fabrication of components, (3) component pro- .. cessing, and (4) scrap handling; these were tied together into a control summary so that the entire effort could be examined and analyzed. Control of Starting Material . . . . . . . ... .. . Control must begin immediately upon receipt of the 'uranium mater- ials. These materials fall into two general categories: solid metals and powdered materials. Solid metals include both pure uranium and alloys, since the fabricator will sometimes avoid the melting and casting step by procuring prealloyed uranium. Powdered materials include such :- compounds as U02, UN, and U308, which are not alloyed but mechanically mixed with diluent. For bulk oxide fabrication, the fabricator may receive premixed compounds, such as UO2-ThO2, UO2-Beo, UO2-C, and Si-Sic-U02. ... ... . . . ... ... .-. --••, ..:- - .. : -::: ...- - - Verification. - Three quantities of the material should be listed in its accompanying documents: net weight of the uranium-bearing material, total uranium contained in the material, and the total 2350 based on enrichment. Verification of all three figures is important to the fabricator, not only because the materials are expensive but also because the fuel may not meet specifications. Net weight is verified with balances, accurate to no less than +0.5 g for the higher enrichments. Total uranium can be chemically verified by potentiometric titration analysis. Isotropic enrichment is verified by mass spectrometry. . If the fabricator receives alloyed - OIN - AEC - OFFICIAL CRNI - AEC - OFFICIAL 10 ORNI - AIC - OFFICIAL ORNL - AIC - OLLICIAL or premixed material, he must develop and use reliable sampling tech- niques to ensure that the uranium 1s both in the proper proportion with the matrix material and homogeneously dispersed. Handling and Storage. - The uranium materials, received in a criti- cally safe container as shown in Fig. 2, are removed and check-weighed on suitable balances. Metals may be placed directly on the balance. Powdered compounds, however, must remain in their inner containers on the balances or be check-weighed in a contained area, such as a dry box, to protect the operator from toxicity and prevent contamination. It is often advantageous for the fabricator to supply his vendcr with permanently tared inner containers so the filled container can be check-weighed. Control Records. - Materials are usually processed by the fabricator in smaller batches than received. Control of the starting materials requires knowing how much material has been received, how much has been 8.58igned to process, and how much is on hand. The preferred initial control is the simple in-out-balance perpetual inventory. To facilitate immediate materials tracing, however, it should include references for each quantity received and the process batches to which the smaller quantities have been assigned. Fabrication of Components "Primary fabrication includes all stages in which the fuel materials are being processed for containment in nonfuel metals. When uranium- aluminum alloy fuel plates are fabricated, for example, the uranium is first dispersed in aluminum by melting, and the alloy is cast in a graphite mold. The ingot is then reduced in thickness by rolling. Fuel cores are punched from the rolled plate, pressed into an aluminum frame of similar thickness, and covered with aluminum plates to form a composite "sandwich" (Fig. 3). Now the primary fabrication is "conplete. The fuel is contained within a composite fuel plate and cannot be altered in weight or content except by destruction of the component. Often alloy fuels are impractical or impossible to fabricate, so that the fuel core is fabricated by dispersion of a powder. For example, aluminum alloys containing more than 30% U are very difficult to fabri- cate, and useful concentrations of uranium cannot be incorporated in stainless steel by alloying. In the powder dispersion method, the fuel OKNL - AEC - OFFICIAL ORNI - AEC - OFFICIAL .. .. . . - - 11 - . . . - - ORNE-AEC - OKUCIAL ORNI - AOC - OFFICIAL - - - - - - - - - - - - - - Bu - ---...-...---.. !. -..-.---..-... compound and matrix are formed into a fuel compact by blending, cold. pressing, sintering, and coining. This method permits excellent distri- bution of fuel and extremely accurate accounting for the critical ingred- ients. Also, the fuel components have two chief advantages over the alloy: (1) greater freedom of selection of fuel and matrix material for better performance characteristics and (2) confinement of the fission product damage to the fuel compound, so that the matrix can better carry the in-service structural load.' Bulk oxide or other ceramic compound component fabrication involves ceramic and metallurgical techniques similar to those used in the dis- persion method. Although the amount of fuel material in the component must be exact, the control is relatively simple since no fuel-matrix relations are involved. and, in this regard, homogeneity is no problem. .' Specification. - In both alloy and dispersion fabrication, one must predetermine uranium content in the core materials to obtain the desired 235U content in the final component. Aronin and Klein (1) have shown that the density method can be utilized with a high degree of accuracy in determining proper composition of uranium-aluminum alloys. Their work has shown a correlation between calculated percentage by weight and analytical results within +0.19% in alloys containing up to 35% v. : ..... However, Martin and Leitten (2), at the Oak Ridge National Laboratory, showed that suppression of Val, formation in the alloy is difficult at the higher uranium percentages and that the correlation becomes inade- quate above 24 wt % U. . .: When the dispersion technique is used, the predetermination becomes even more difficult because of the additional variables involved. These · variables, which have a direct effect on the density of the fuel core compact, include the uranium content of the fuel compound and the size, shape, and density of both the fuel and matrix particles. ' Where homogeneous fuel cores are the same size and fabricated from a single melt, the average weight method for determining fuel. content in each component is very reliable. The entire batch of components from a single heat is weighed and total weight divided by their number. If an extremely close tolerance is desired, the content is determined from a density measurement of each component. . . wo..- - ---. - - - - - - ORNI-AIC - OFFICIAL interest interior andere trikraidan ORNI - AEC - OFFICIAL online '.:: :1..., *HE 12 ORNI - AEC - OFFICIAL ORNI - AC - OFFICIA: Verification. – A pilot fabrication effort with liberal destructive testing of the end products will be used by the fabricator before actual production begins. This facilitates prediction of the end result with enough certainty to assure general control during actual production and, in many cases, is one of the best methods of product verification. Homogeneity of dispersion products, for instance, is often based on integrity of the process and depends almost wholly on intelligent opera- tion and close control during fabrication. Even though many advances have been made in the field of nondestructive testing for confirming homogeneity, fuel quantity, and other specifications (3), any such con- trol methods remain secondary to process integrity. In alloy fabrication, however, content may be verified by wet chemi- ** cal analysis of dip sampl.es taken from each melt before casting. The samples are very representative, and measurement at this early stage permits some adjustment of the uranium content by adjusting the thick- ness of the fuel compact before primary fabrication is complete. These analyses must be evaluated to determine if the uranium content of the material is acceptable. The establishment of criteria for accepta- · bility depends on two uncertainties in alloy content determination: (1) the disagreement between the chemical analysis and the intended composition and (2) the limits of error in the sampling and analysis. These must be examined collectively to determine if the fuel content specification has been met. The average analytical result rather than the intended ccimpo- sition is depended on to correct any mechanical or human errors that have occurred in the process. **Control Records. The form records used in the control of enriched uranium during the primary fabrication process differ from plant to plant even more widely than do the fabricated shapes they control. In every case, however, they should answer three basic control questions: : (1) Where is the material located? (2) What is its physical shape? (3) What is its quantity in relation to the matrix materials in which it is dispersed? . Figure 42 illustrates a practical log that records the desired : information and supplies the necessary control facts. This form is readily adaptable to other, alloy fabrication, such as the casting and extrusion OWNL-AEC - OFFICIAL ORNICAEC - OFFICIAL ... is .. - t . ORNI - AC - OFFICIA: KNI- AC - OFFICIAL 13 i of rods, since the same facts are required. Note that the uranium per- centage applied to the net alloy weights is the average of the analyses of the dip samples. Note also that a great deal of information has been practically condensed into a single control record and reflects the ..' relationship of the categories in a single presentation. . The type of control record used for dispersed fuel materials is very similar (Fig. 46). Since there are fewer steps, the record is somewhat simpler. It does, however, adequately reflect the steps and provide the necessary control information. The same form is also useful for the primary step in bulk oxide fabrication. Component Processing "Secondary fabrication" relates to work on the fuel components after they are completely contained in nonfuel metals. Since changes in the uranium content of the components are now impossible without their . destruction, material control becomes relatively simplified; only a piece identification is necessary. . The most difficult task in controlling secondary materials is to maintain identification of small, individual components until they can be permanently marked. The use of batch containers is a good method for maintaining identification as well as transporting the pieces through the early stages of secondary processing when the components are in groups of identical pieces and can be interchanged. Such a container should be compartmented to accommodate any rejected pieces as they occur in the process. Once the components have been permanently marked, usually by etching or stamping, the batch container is no longer needed and can be diverted to new batches of components. Control of the Final Assembly. - If several of thė small components are to be further processed into a fuel assembly, control shifts from individual component identification to assembly or fuel element identi- · fication. Components from different batches will often be mixed to attain fuel content within a close tolerance. The control shifts when the plates are sellisted and temporarily assembled by taping or tying and should be so recorded. ORNICAEC - OFFICIAL ORNI - AEC - OFFICIAL OIN! - AEC - OFFICIAL 14. Control Records. - Secondary fabrication records fall into three categories: (1) component processing records, (2) component disposition records, and (3) assembled component records. Figure 4c illustrates a record for controlling the materials during component processing. This batch control record accompanies its group of components through all stages of processing, accounting for the com- ponents, and collecting information concerning rejections. When complete, the record is filed with the previous batch log (Fig. 4a or b) and the two serve as a complete materials and process control from receipt of the starting materials through component processing. If desired, the two cards may be merged into a single control record which is initiated with the starting materials. At this point, the fuel components may be finished products or may require further assembly into multicomponent units. In either case, a record should be made to indicate the disposition of the finished . . accepted components. Figure 5a is a record that initially records the temporary storage of a finished component batch. Their shipment, or .. further processing into assembled units, is indicated as it occurs, and their disposition is permanently recorded. Materials control during assembly is very similar to batch control. A record is made of those components selected for assembly into an element and follows them through the assembly process. The element assembly record, illustrated in Fig. 56 was originally designed for the collection of data during assembly of an MIR element containing curved plates. This record is also a good illustration of how one may integrate the maximum number of controls into the minimum number of records to eliminate dupli- cation. Scrap Handling OIN - AEC - OFFICIAL Scrap materials, which can occur at any time during the fabrication' process, must be disposed of by either recycling through the process or reclaiming through chemical recovery. When economically' feasible, scrap may be buried or otherwise safely destroyed; this rarely occurs, however, with the use of highly enriched material. OINT-AIC - OFFICIAL ORNI - NEC - OFFICIAL . ... 15 . . . Alloy residues of good quality can be remelted with additional uranium and aluminum to form a new ingot, 80 chemical recovery is not economically feasible unless the process is closed. Rejected components can often be remelted with the alloy residues if no contaminants that would damage the new alloy are present in the cladding materials. Some residues, like heat dross from the top of the alloy melt, con- tain so many impurities that they must always be removed from the process and recovered. Also, rejected powder compacts can be recovered only by chemical means. Since enriched scrap usually occurs in relatively small amounta, it is recovered most inexpensively by accumulating several small quantities into a larger batch for a single recovery operation. Such a batch is, of course, limited by criticality considerations. .. . Control Summary The final control procedure in the fabrication of enriched uranium dictates a summary and general examination of the entire process. The total amount of uranium material that has entered the fabrication plant must be compared with the total amount on hand after p ressing, and pro- cess differences must be determined. In addition, all records should be for any trends that would affect the process or components. The Material Balance. - The materials before and after processing are best compared by the material balance. In this method, the process is either actually or theoretically cut off at a selected point. Usually, an actual cutoff occurs only if the product is changing and different .. specifications are involved (such as a different uranium enrichment), necessitating an equipment cleanup and resetting or retooling. Pure and unclad materials are weighed and counted and their uranium content is computed. The clad or contained materials are counted and identified, and fuel content is established from their fabrication records. On completion, the inventory is checked against closing balances indicated on all previously discussed control records. The inventory listings are posted to a previously prepared worksheet which already bears the ending control record balances. In some cases, this worksheet OINT - AEC - OFFICIAL ORNI - AEC - OFFICIAL ; ORNL - AEC - OFFICIAL is given to the personnel taking the inventory as a guide; but when this is done the advantage of a "blind" inventory requiring a thorough search is lost. The uranium content values computed for the inventoried materials listed on the worksheet are now summed and drawn into an actual balance against all materials charged to the plant (Fig. 5c). Process Differences. – Note that the uranium content of the heat dross in this particular balance is determined three ways: as the uranium percentage in the alloy, as the difference between inventory and book balance, and as the actual recovered content. Only the last is significant in determining the normal process differences that will occur, as the impurities in the heat dross will vary rather extensively from batch to batch. Indeed, on first drawing the balance using the percentage, , one will more often experience a process gain rather than a process loss, a good first indication that the final balance will fall within acceptable limits of error if such a gain is small.. What, then, are acceptable limits of error for the process? The answer to this question is tied directly to two considerations: (1) the collective measurement limits of error for the process and (2) the fuel specifications of the fabricated products. If the process difference falls within these limits it is a reasonable one. If it does not, individ- ual process circumstances must be considered and the process records must be reexamined to isolate the process stage or stages where it occurred. Sometimes, additional checks must be made, such as x-ray examination, further component sampling, or a chemical analysis of the related backup dip samples. In any case, the fabricator must be satisfied as to the pro- duct fuel content, for there is no practical adjustment after the com- ponent has entered the reactor. Process losses of raw material also affect the product cost, espe- cially when expensive enriched uranium is the raw material. If a rela- tively large process loss occurs, even though the components meet speci- fications satisfactorily, the cost of enriched uranium requires that the process be reexamined and adjusted to make any possible reduction of this loss. ONL - AEC - OFFICIAL 17 ORNI - ALC - OISICIAL ORNI - ACC.. Oricia Process Evaluation. - In addition to a recheck of all measurements and values reflected in the process records, a thorough analysis and evaluation of the total data are important. Such factors as dimensions , consistently on the high side set patterns of intended fuel content versus intended result, and, constant recurrence of unusual effects or normal defects will often reflect areas in the process requiring further development work. Another important aspect of any fabrication effort is the maintenance of a good ratio of product yield to materials processed. The scrap, 'waste, and yield record (Fig. 50) illustrates a good approach to determining this ratio. It also provides a scrap analysis for determining process trouble spots. SUMMARY Control of enriched uranium during its fabrication is important . because of the scarcity, expense, and special hazards of the material, and because technical success in the manufacture of reactor fuel elements depends on how well its controls are designed and applied. The relation of these factors to the particular fabrication process must be considered before one can properly select and establish controls for that process., The basic objectives in control system design include completely inte- . grated records for a minimum number of material units in each major fabrication step confirmed by reliable cross checks Control procedures must be established to provide data needed for the ultimate material balance. From this summary, process gains or losses are determined which either confirm the product fuel content or indicate the need for further examination of the control data and fuel components. Two other results are evident in developing proper control procedures. First, as production proceeds, the number of units to be controlled decreases; and the higher the rate of decrease, the more efficient and simplified the control procedure becomes. Second, the data generated during the control process can form significant patterns that point to possible trouble spots in the fabrication effort. ORNL - AEC - OFFICIAL ---ORNI - ABC - OFFICIAL PRnl AEC - OFFICIAL 18 REFERENCES (1) L. R. Aronin and J. L. Klein, Use of Density Method as a Sensi- tive Absolute Measure of Alloy Composition and its Application to the Aluminum-Uranium System, USAEC Report NMI-1118, Nuclear Metals, Inc., Oct. 29, 1954. (2) C. F. Leitten and M. M. Martin, personal communication, Oak Ridge National Laboratory, May 1965. 13) ,R. W. McClung, Development of Nondestructive Testing Techniques for the High Flux Isotope Reactor Fuel Element, USAEC Report ORNL-3780, Oak Ridge National Laboratory, April 1965. nal Laboratory.ement, USAEC Report** SUGGESTED READING : R. F. Lumb (ed.), Management of Nuclear Materials, D. Van Nostrand Company, New York, 1960. Subcommittee 8, ASA, and Project 8, ANS, Nuclear Şafety Guide, USAEC Report TID-7016-Rev I, Goodyear Atomic Corporation, 1961. H. C. Paxton, et al., Critical Dimensions of Systems Containing U-235, Pu-239, and U-233, USAEC Report TID-7028, Los Alamos Scientific Laboratory and Oak Ridge National Laboratory, June 1964. B. E. Foster, s. D. Snyder, and R. W. McClung, Continuous Scanning X-Ray Attenuation Technique for Determining Fuel Inhomogeneities in Dispersion Core Fuel Plates, USAEC Report ORNL-3737, Oak Ridge National Laboratory, January 1965. OXNL AEC - OSFICIAL ORNI - KTT- OFFICIAL ORMI-AIC - OFFICIAL 19 FIGURES Fig. 1. Representative Fuel Element Types. Refs. (a) J. E. Cunningham and E. J. Boyle, "MIR Type Fuel Elements," Progress in Nuclear Energy 1(V), McGraw-Hill, New York (1956), 544-550. (b) J. E. Cunningham et al., Specifications and Fabrication Pro- cedures for APPR-1 Core II Stationary Fuel Elements, USAEC Report ORNL-2649, Oak Ridge National. Laboratory, Jan. 29, 1959. (c) Personnel of the Naval Reactors Branch, The Shippingport Pressurized Water Reactor, Addison-Wesley, Reading, Mass., (1958), 78–84, 151–158. --- -- Fig. 2. ,Metal "Bird Cage" Type Shipping Container. Uranium materials are placed in the center container for shipment. Criticality - - . ..-'. - - - - --- - Fig. 3. Exploded View Showing Makeup of Fuel Composite. Dimensions are approximate and will vary with specification. ' - - - - - - Fig. 4. Typical Records Used in Uranium Materials Control. (a) Alloy Heat Log. (b) Blended Materials Batch Log. (c) Batch Control Card. Fig. 5. Typical Records Used in Uranium Materials Control and the Material Balance. (a) Component Disposition Record. (b) Fuel Unit Fabrication Record. (c) Uranium Material Balarice. (a) Scrap, waste, and Yield Record. ORNI - AEC - OFFICIAL ORN - AEC - OFFICIAL . TV350-33V - INIO WIDI310- 33V-INIO - - - - ..... -COVER SHEET Q.asm - FUEL BEARING ALLOY OR POWDER PRESSED CORE len - FRAME PECE . MUITOMOB ii,':'! . . . - COVER SHEET ';';;!;;! . in me ZINNIANHAMCOMOO . . -.- Lions i ܘܙܙܫܙܕܙܙܘ - -- -- --- Fig. 2. “Metal "Bird Cage" Type Shipping Container. Uranium materials are placed in the center container for shipment. Criticality spacing is maintained by the outer frame. Fig. 3. Exploded View Showing Makeup of Fuel Composite. Dimensions are approximate and will vary with specification. ORNI - AEC - OFFICIAL ORNL-AIC - OFFICIAL ORNL-AIC - OFFICIA ORNI - AEC - OFFICIAL guicide.co.co... les in e ... x 4 .... v ..... . WIN1 WW , :: S VIIVIT m ww ställare MUKH : . STAINLESS STEA CLADONG - STAINLESS STEEL SPER PLATE UMINUM SPACER PLATE IV ! ZIRCONIUM OR STAINLESS STEEL TUBE SLIGHTLY ENCHED VOZ- ENRICHED UO, STAINLESS STEEL POWDER CORE (d) Dispersion Fuel Plate Element - APPR Reactor. Bulte Ouide Aod Element - Power Avoctor. MICHED URANIUM ALUMINUM ALLOY CORE ALUMINUM CLADDING- (a)' Alloy Fuel Prote Dornant - MTR Rooctor. Fig. 1. Representative Fuel Element Types. Refs. (a) J. E. Cunningham and E. J. Boyle, "MTR Type Fuel Elements," Progress in Nuclear Energy 1(V), McGraw-Hill, New York (1956), 544-550. (b) J. E. Cunningham et al., Specifications and Fabrication Procedures for APPR-I Core II Stationary Fuel Elements, USAEC Report ORNL-2649, Oak Ridge National laboratory, Jan. 29, 1959. (c) Personnel of the Naval Reactors Branch, The Shippingport Pressurized Water Reactor, Addison-Wesley, Reading, Mass., (1958), 78–84, 151–158. . OKNI - AEC - OFFICIAL ORNI - AIC - OFFICIAL ITIDIS10 - )Y-INYO 1091310- 33V - INYO ALENDED MATERIALS SATCY LOG . to criw Order Nie. Blond No. EB-284 نے دو دانه u al اراک - ' | Pyme Material ut 5 Uranium Ivo,-Aluminual 47.00 IECIKNING MATERIALS identification Mor Weight Fabrication Onder Na ila? 84 1 WET Tyme Material Paralu ALLOY MEAT LOC How No. [ Tran karneval wonded attu a .U by dog. Chen Ansigua :5.91 129_R2R I MINC WATCH Tyga kletarial I dontifoc atran wilco.com Tecolu 176- 842 | 120.14 1120.14 648.13 Alley icra E- 497 1654.12 | 239.02 | 215.12 Soros Components 3 Plates (E-492 1 591.22 25.17 22.65 Sarap Corsenons 2 Plates E-494 1 393.68 16.744 15.07 : Soros Congemeno 2 flatul E-500 1399.10 20.13_ 19.12 Corner Marie Higke Perito al Mitch 13646.28 1 IC-927 11011.63 | E0-283 | 72. al 890.23 5.86 118.05 1.17 üroniva V Residue from Previous Blond in Materiel & Powder Other Material Total Blond $43.01 : - Tood Maresmedlem 16402.48 11021.20 919.09 LOY PRODUCTS (a l a hitory Ballero Alther Samples 1 E- Soy 16036.281 973.581 876.21 MI AR 15.99! 6.62 1.06 0.95 Ma a 15.96 6.40 1 1.02 L0.91 13 ar 15.95 6.57 1 0.73 0.66 I Beat Brow L 315.80 | 50.43 45.39 1 6429.67 | 1026.82 | 924. 14 +27.191 +5.621+5.06 COMOMENT ROOUCTS | 16 C 4481.911 115.12 1 644.33 (51.181 1 19.42) L (1.48) 1611.24 257.32 231,57 No. Accepted'o Prossed Coast Average weight Accortable Corp. Rejected Components Unused Blond Rosiduo Teal Component Products Blond Comperent Difference 1866.85 | 896.091 179.22 COMPONENT PRODUCTS 1759.42844.51 148.90 (92.60) (44.45) 18.991 91.60 44.45 5.89 10.61 5.09 1.02 1862.63 1894.06 178.81 4.22| 2.03 | 0.41 Panel Allery d. When 1. When herhale : Padel haberto i Allas - Cressen Ditherance 16 - Amerymed Rosendo BATCH CONTROL CARD Batch Na E-514 Number Compone ons_76 Tyme al Alloy Pleten Processed] Stengt Rojociions and Roosen 6094.18° i 173.2's L -2.13 -0.34 975. 91 -0.31 Inc OK OK | 2. Cover TO Fig. 4. Typical Records Used in Uranium Materials Control. (a) Alloy Heat Log. (b) Blended Materials Batch Log. (c) Batch Control Card. Roll .1 s ound an OK 3. Her Roll CH OK VI CUP 1-0.057 1. Amoel lent 2-Blister luwe & Flueconomy lows 13-Care of Tal. Lowe Dwa ok Tw& 10. Machine ICARI OK lak 11. Anael IHLI-Blistus wwp 12. Inspect Www.pl 1- Thin Edge wwe Total Accepted Components ro Storage 68 ..Terel Scropped Components 9. Sheer Torel Scropped Components ļ ORN - AEC - OFFICIAL ORMI-AIC - Of ENAKCHED URANIUM MATEN AL MLANCE Torel Uranium U.235 Grom Disposition COMPLETED COMPONENT DISPOSITION RECORD Hent or Batch No. 31% t - 314 everal Average Total U Ench componene ___ 9.43_8.4 Number Corrgonents Balance on Hand Date In Our 801 Total U U?IS Received for Storage 16-12-581681 168 640.56 1 576.64 Element 1-10216.14.38 12 156 537.32 474.88 thirut 1142-414-15.58 92129 213.18 245.92 Clemat -12116-24-58 116113 122.46 110.24 Clement 1-1236-25-58 1914 37.68 - 33.92 Elegat 1-12216-27.58 4101 -0 . Period: July 1 - 31 iro Material: sox Enriched Cranho Alloy balance on Hand, dne 30 | Tarel Receipt - July Total Previews kelance and he ceipts Loss Total Shipmenn - July Delance on Hand, July 31 17.00 *.724 15, 2013 02.147 1.60 14, 25, RS 0,m Macheter lain loventary beginning Materiela į Moteriais in Procasa Hilat 2,482 1.31 . Cor Romelt Alley from Punchings Product Motortela: Assembled Element itor 11.2000 Serap Ahotorteds for Recovery: Men By Weight and Strankan by Olthovenes TOTAL AVENIONY 23, Procon Difference (Low) ، های، داوو..ودعا " || awwenwo mu ncome Y-7897 PATE DATA KATE SPACANG, MUSI CRITS OWENSIONS, INCHES forel U U s 1 fotel u Tongs L achen, Andres Par Plano ! Per Plate | Mar 212161 Islovom Saputra Long | 2 18.69711.795 17.394|15.510 1.2 ] 11211193; 3.9133770.3.oe sous 0240 vse 242.991 2.901.3.191 1.070o 341 119.69317.783 1.6831 7.113 11191115 |u5|116 US12 2.905 1.990.7.1999.0086 3ww. E-sog * 18.707 7.864 34.885 31.210 -s|17|17| E-goras (4 [8.138|283296118 16.152) s. 118112 113u7] 21 [2.995/2.99,\2.993/3 065/0.145 1 1/2111311 w; 1.992.2015 2.1903 0735.240 Grand Toral | | Torsi U-235 in Assembly 1140.741| + |118017112117 Pieno Specing 117 is: 12 saan ELEVENT PLATE POSITIONING 118 Piom Thickness: Sudo Plan: 3/16 no Cunter Plan a dobo inch | 102 US 120 119 vs Suche Plens Breue Cloud & Bruno one! 11-1211181119 122 117 Romanti: Tatoto socco 1201141141105 18 Curved plate assembly O nar PucaBLE 13.111191119 plates. Long top and button teroro assut OrigO ASSCHALT IS16WZ 115 120 417 Plate content head on 16171181124 1191120 Aurage analysis of dip sample talla prima 17.10122111311201231 22 2235 For truenery - Colouderad Va O Motos ind 1011 1213 ទី១ ទីទី ទី១៩ ទី១ 1.615 1 / .ادر . : 4-51 7231 4:54 | L 315.80 $0.43] #3:39 14-515 161 £Si 30 289.72|62.07 55.86 E-916 741 E-S16 E-517161 E-:111 hot 291451 54.76 49.28| 1E-5707U 4.578 14 3 : 63.11 56.10 Toate [3781 82|4|4|8l4lsolsoi-11572 361 280.82251.12125313/2276-2507 2528 PUIL UNIT PAIRICATION RECORD Fig. 5. Typical Records Used in Uranium Materials Control and the Material Balance. (a) Component Disposition Record. (b) Fuel Unit Fabrication Record. (c) Uranium Material Balance. (a) Scrap, Waste, and Yield Record. ORNL - AEC - OFFICIAL ORNL - AEC - OFFICIAL . :I. END DATE FILMED 9/ 2 /65 ! L .