Atomic Energy, Vol. 89, No. 4, 2000

RAW MATERIAL PROBLEMS OF THE NUCLEAR FUEL CYCLE

V. V. Shatalov

According to data from IAEA and the London Uranium Institute, the worldwide consumption of uranium in 2000 is estimated to be 64 thousand tons/yr and the production only 40 thousand tons/yr. The deficit is covered by reserves (up to 25 thousand tons/yr), the production of mixed uranium–plutonium fuel, and recovered uranium. The last two sources will comprise no more than 5–7% in the foreseeable future. Highly enriched uranium up to 10 thousand tons/yr makes a substantial contribution up to 2010. New substantial uranium ore deposits in Canada, Australia, China, and Russia will be exploited up to 2010. However, at present this program is lagging behind the planned levels. Thus, the deficit in the production and consumption of natural uranium for any scenario of development of nuclear power is 20–25 thousand tons/yr and the cost of uranium will be determined by the countries which possess large reserves. In this connection, starting in 2010, deposits with the produced uranium costing more than $52/kg will be gradually brought into production. The consumption of natural uranium in Russia is determined by the capacity of the nuclear power plants operating in the territory of Russia, Ukraine, and in eastern Europe, and taking account of the program of development of nuclear power up to 2010 it is equal to 8.5 thousand tons/yr in 2000 and will gradually increase up to 9.2 thousand tons/yr by 2010. The consumption volumes in Russia and other countries are approximately the same. Fundamental scientific investigations of the chemistry of uranium are becoming important. They include the following: – investigations of the chemical-mineralogical composition and degree of stability of the minerals; – directed synthesis of stable minerals; – study of the reactivity and oxidation-reduction powers of the systems water–solid, water–organic material–solid; – development of solvometallurgy; – study of the migrational power of radionuclides in geochemical zones; – complex formation and the mechanism of ion exchange; – mechanisms of dissolution and complex formation of uranium and the basic accompanying elements in solutions of acids and alkali; – synthesis of organic compounds with prescribed physicochemical properties (extracting agents, sorbents). The operating technological reprocessing schemes, making it possible to increase the degree to which the reserves of deposits are used, to reprocess high-grade concentrates, and to produce low-waste, ecologically clean products, must be radically altered on the basis of these investigations. The directions of the scientific investigations concerning the uranium technology include: – development of methods of physicochemical enrichment with production of concentrates with different degree of persistence; – development of a new technology for using oxidizers for leaching; – development of a technology for processing ores on location by the method of underground leaching; – development of methods for continuous-flow sorption of uranium and other elements in a dense layer of an ionite for reprocessing large solution volumes; – investigations on minimization of wastes, containing natural radionuclides, and others, and development of low-waste production.

All-Russia Scientific-Research Institute of Chemical Technology. Translated from Atomnaya Énergiya, Vol. 89, No. 4, pp. 334–338, October, 2000. 1063-4258/00/8904-0853$25.00 ©2000 Plenum Publishing Corporation

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In 1998–1999 a large volume of work was performed on assimilating two experimental test areas for underground leaching, including the Dalmatov and Khiagdin deposits. Drilling, restoration, and assembly work were performed for operational wells, acidification of strata was performed, and setups were produced for reprocessing the production solutions. In 1999–2000 valuable experience was gained in operating the sections under winter conditions; this will make it possible to develop real programs and provide the initial data for designing and constructing commercial programs. In the coming years it will be necessary to initiate work on the use of the new leaching technology, reprocessing solutions, and obtaining a chemical concentrate; this will include the technical–economic indicators of the underground leaching sections. For reprocessing of ores from the Strel’tsov ore field, work was performed on stabilizing the basic technological parameters of the hydrometallurgical plant, and suggestions were developed, jointly by PPGKHO and VNITIPT, on radically changing the production work using radiometric enrichment methods. It was shown that on account of the changes in ore reprocessing technology and rational distribution of ore fluxes with different reprocessing methods there is a real possibility of stabilizing the cost of reprocessing, even as ore quality decreases. Work on switching to a mining-chemical technology using bound and block underground leaching has begun. The first 200 tons of uranium have been obtained in 1999 with this technology. Further elaboration of underground leaching methods at the Priargun Mining-Chemical Combine requires new advances in physicochemistry and the development of a new-generation technology, equipment, and ionites and using them in production. Only this path will ensure that the production is competitive, and the results obtained in 1999 clearly show this. The rise of the defense industry in the USSR was based not only on the uranium raw material base but also on the production of other special materials, whose raw material base was also adequate. This concerns, first and foremost, strategic metals, such lithium and beryllium, as well as constructional nuclear-pure metals – zirconium, hafnium, tantalum, and niobium. Some important production has been stopped, first and foremost, the production of lithium and beryllium. The raw material base for the production of compounds for constructional materials (zirconium, niobium) and fuel assemblies (rare-earth elements and others) is changing radically. Such production has been found to depend on deliveries of raw material from the Commonwealth of Independent States and China; this is incompatible with maintaining the national safety and economic independence of Russia. Before 1990 the Ministry of Atomic Energy of Russia was the producer of many initial compounds (beryllium, lithium, rhenium, scandium, tantalum, and others) for production of constructional materials not only for nuclear power plants but also for defense enterprises. On this basis there was a connection with petroleum reprocessing (catalysts for cracking petroleum based on rare-earth metals) and the optical industry (polishing powers, luminophores, and so on). This made it possible to develop conversion applications and to meet the country’s defense needs for superconducting conductors, instruments, strong magnets, refractory alloys, optical fibers, solid-state fuel elements, and so on. Now, there is no raw materials base within Russia for almost all of these directions, and such a base must be developed anew. The directions of development of a raw materials base can be classified as follows: – raw materials and production from them, directly used in nuclear power plants of different types; – raw materials and production used in accompanying production of nuclear power; – materials of high purity or strength, which are used in other areas (defense, electronics, and so on), which require high-technological components, including in conversion programs; – raw materials and production from them for purposes of loading capacities for the production of liquid products (gold, copper, platinoids, and so on) on the basis of advanced technology. It should be noted that the consumption of nuclear-pure compounds in the enterprises of the industry is low and high-profit production of high-price, technologically finished products is possible only if all approaches are solved. The industry possessed almost all forms of production to satisfy needs, and a technology was developed for reprocessing complex ores, which satisfied the needs and all associated conversion programs. This is especially evident in an analysis of the reprocessing of zirconium and rare-earth elements. Zirconium. Zirconium concentrate is obtained from Ukraine; it is processed up to the final products in the Chepetsk mechanical plant. By 2003 this zirconium deposit will be depleted, but there is no replacement in Russia. This makes it necessary to develop exploratory and technological work based on the Russian deposits “Katuginskoe” and placer deposits in the Transurals and the baddelite concentrate “Kovdor,” which would make it possible to obtain zirconium concentrates with the required quality and to process them at the Chepetsk mechanical plant in amounts up to 4 thousand tons/yr.

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In addition to a reliable supply of raw material for zirconium production, it would also be desirable to organize the production of high-purity zirconium dioxide for fiber optic needs, engineering ceramics, current sources, and other needs in amounts up to 1000 tons/yr. The preparation for a radical reconstruction of the chemical processing of zirconium is in progress. A gas-chloride technology for discovery and deep separation of zirconium and hafnium, followed by magnetothermal production of zirconium, is under development. In addition, the possibility of using an extraction technology for separating metals is also being considered, especially since there is experience in using modern equipment based on centrifuges. The main point of this work is not to lose quality, since the domestic constructional materials require higher indicators than foreign materials. Rare-Earth Metals. These are finding increasingly wider application in the nuclear industry (control rods, steel, fuel components) and in civilian production. On account of the mastery of the new technology, in processing uranium ores a large amount of rare-earth concentrates (up to 60% of the total production in the USSR) was obtained in the process; individual metals and their compounds were produced from these concentrates. However, the enterprises in Kazakhstan, Ukraine, and Russia have been shut down. In 1998–1999 a great deal of work was performed on organizing in the Chepetsk plant the processing of chloride melt from loparite from processing performed at the Solikamsk plant. A technology has been developed for processing the reserves of monazite concentrate in the Sverdlovsk region and for separating carbonates of rare-earth metals from production solutions accompanying the reprocessing of apatite. The adoption of a program incorporating the new forms of technology will make it possible to produce up to 2000 tons/yr of compounds of rare-earth metals and not only to meet the needs of Russia but also for export and to restore links with other branches of industry. Fluorine and Fluorine Derivatives. Large production facilities (all in Russia) for producing hydrofluoric acid, hydrogen fluoride gas, and elemental fluorine have been constructed for the production of uranium hexafluoride. The technology developed makes it possible for the producers in the various ministries to become the largest producers of metal fluorides, fluorine derivatives of different kinds, to develop new solar silicon production, and so on. The technology and equipment are produced domestically. The production of fluoride compounds, first and foremost, uranium hexafluoride, is based on this. The raw material for this production was fluorite obtained from deposits in Russia, Central Asia, and Mongolia. Unique schemes for preparing and processing the raw material, which provide high quality of the final product, were developed. The quality of the raw material is now much worse, and the prices of imported raw material are obviously trending upward. This makes it necessary to produce an industry raw material base and to develop production based on the production areas being freed up in the Trans-Baikal Mining-Enrichment Combine from ores from the Égitin deposit with concentrate production up to 70–100 thousand tons/yr. Lithium. Before the disintegration of the USSR, Russia was the second largest producer in the world of lithium and lithium compounds. It produced 8–9 thousand tons/yr in the carbonate equivalent. The producer of lithium compounds, the Krasnoyarsk chemical-metallurgical plant, also produced cesium and gallium (metal) in quantities of 200–250 kg/yr, required for electronics, from spodumene concentrates. When the ore from the Zavitinsk deposit was depleted, the production of lithium in Russia stopped (in 1997). At the present time the Krasnoyarsk chemical-metallurgical plant is processing, based on an agreement with the company “Minsal” (Chile), imported technical-grade lithium carbonate and planning to produce lithium hydroxide, water-free chloride, and metal. The Novosibirsk plant producing chemical concentrates has made an agreement for reprocessing lithium wastes from the amalgam-exchange production in the USA (separation of lithium isotopes) and is planning to produce lithium hydride and carbonate, nonhydrated lithium chloride, and lithium metal. Thus, from the standpoint of providing for idle capacity, the problem has been solved. At the same time, a complex technological scheme (gypsum-lime) for extracting lithium from greisen ores from the “Étyka” deposit has been developed at the All-Russian Scientific-Research Institute of Chemical Technology for processing new types of domestic raw materials. Together with lithium, sodium sulfate, sulfoaluminate cement, cesium and rubidium salts, and primarily cesium, for which there is a large demand abroad, can be produced. Comprehensive use of the raw material makes possible production at a cost close to the 1999 prices: lithium carbonate at $3.2/kg and lithium hydroxide at $4.2/kg. In addition, work on other forms of raw materials must be developed, first and foremost, the extraction of lithium from hydromineral brines. 855

Beryllium. Before the disintegration of the USSR, beryllium production at the Ust’-Kamenogorsk metallurgical plant was the highest in the world and equal to 200 tons/yr. The products made from the undoped beryllium were at least of the same quality as foreign products and were used primarily in nuclear and aerospace technologies. The demands of the nuclear industry did not exceed 20–25 tons/yr. Beryllium bronzes were of higher quality than the European products and had no limits in the market. The best acoustic systems in the world operated on Russian bronze diaphragms. The quality of beryllium metal optics was at least as good as that of the American product. Constructional beryllium alloys were produced on a large scale. Beryllium oxide ceramic was widely used for producing microcircuits in Russia and abroad. Reserve stocks of beryllium concentrates, previously produced in Russia, including also unique concentrates from the Ermakov deposit, containing 11–14% BeO, have remained in Kazakhstan. According to data from FTSP “Libton” production should be restored up to 60 tons/yr of beryllium. In addition, the plant should be constructed on the industrial site of the Trans-Baikal Mining-Enrichment Combine, since it possesses an enrichment factory for producing beryllium concentrates from ores from the Ermakov deposit. However, no decision has been made concerning the construction of such a plant, and consequently deliveries of beryllium production from Kazakhstan must be arranged. Niobium, Tantalum. The raw material base of these metals is connected with two deposits in Trans-Baikal “Étyka” and “Katuginskoe.” The Katuginskoe complex deposit (niobium, tantalum, and zirconium) is of great interest. Its assimilation will depend on the time required to build a railroad. Both deposits can supply operations for a long time. A commercial pilot operation of an enrichment factory was started in 1999 as part of the “Libton” program, and a facility for comprehensive reprocessing of ores with production of 40–60 tons/yr of niobium and tantalum is being designed, i.e., all needs for these metals will be met. In 1999 a great deal of work was done on working out a technology for obtaining 7% concentrate followed by hydrometallurgical reprocessing. This makes it possible to reduce the reagent consumption sharply. Other Metals and Materials. Metals such as scandium, rhenium, tungsten, and certain other metals are important for the defense and aviation industries. Enterprises of various ministries have experience in this field, especially with secondary extraction from production solutions from underground uranium leaching. Large gold-bearing territories are located in the regions where the secondary enterprises of the ministries are operating. In the last few years, even though the production of gold has generally decreased, new gold-producing enterprises have started up. From this standpoint it is desirable to organize work on underground leaching of gold and processing of technogenic products. According to preliminary estimates, tens of deposits with reserves ~20–30 tons can be used for this work. Production of up to 6 tons/yr of gold can be organized quickly using the underground and mound leaching technology (the payback time is 2–3 yr). This work is highly profitable, but licenses for the deposit must be purchased.

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