Uranium Enrichment Projects

During the period from 1943 to 1947 in the United States, the Manhattan Project carried four uranium enrichment processes through the large pilot stage and into production to the extent noted below. 

Gaseous diffusion. Table 14.3 lists gaseous diffusion plants in operation in 1977 and those then under construction, planned, or under consideration. Part 1 of Table 14.3 lists plants in operation at that time. The three large plants of the UJS. Department of Energy (DOE) had a capacity of over 17 million kg separative work units (SWU) per year when supplied with the maximum amount of electric power, 6100 MW, they could then utilize. 

plant is rumored to have an aimual capacity of from 7 to 10 million units, of which 3 million are thought available for export. The existing plants of the French Commissariat a TEner e Atomique (CEA) and British Nuclear Fuels, Ltd. (BNFL) are too small to be a major source. Little is known about the Chinese plant. 

Owner Location Capacity, million kg separative work units per year  

Coredif (Eurodif, CEA, Iran) France, Belgium, or Italy 5.4 Late 1980s 

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Fishman, A. M. A. I. Chem. E. Symposium Series No. 169, 73 (1977). Developments in Uranium enrichment, 43. The centar gas centrifuge enrichment project Economics and engineering considerations. 

The enrichment capacity of Eurodif is 10,800,(XX) UTS (units of separation work). This corresponds to the fuel consumption of 90 nuclear reactors of the 900 MW class. In view of all the programs for building nuclear power plants hastily set up by many countries shortly after the 1973 oil crisis, it was clear that another uranium enrichment plant of similar size would have to be built immediately after Eurodif was completed. This was the Coredif project. 

Setde, Frank. Nuclear Chemistry Uranium Enrichment, Available online. URL http //chemcases.com/nuclear/nc-07.htm. 2005. Accessed February 12, 2006. This site provides coverage of the purification of uranium during the Manhattan Project. 

Teflon, discovered in 1938, does not burn. It does not melt below 620 degrees Fahrenheit but rather turns into a translucent gel. It does not conduct electricity at aU, does not combine with oxygen, does not dissolve, is unaffected by acids, and is immune to molds, fungi, and bacteria. It was deemed completely useless until it was found to be the only material in existence that could enable the uranium enrichment process used in the Manhattan Project. When finally made available for public use, it was as nothing more exotic than a nonstick coating for cookware and steam irons. 

Fig. 7.8 presents two examples of fuel composition evolutions for a 3 GWth reference MSFR reactor started with or TRU. An optimized fuel salt initially composed of LiF-ThF4-enriched UF4-(TRU)F3 with uranium enriched at 13% in and a TRU proportion of 3% (see Fig. 7.9), has been selected in the Irame of the EVOL project taking into consideration the neutronics, chemistry, and material issues. 

Nuclear Regulatory Commission, civilian agency following AEC to monitor nuclear materials and commercial nuclear power plants Nuclear Steam Supply System Office of Naval Reactors, Navy group responsible for reactor design, operation and safety Manhattan Project site for Large Scale Uranium Enrichment... 

Supply Projections. Additional supphes are expected to be necessary to meet the projected production shortfall. A significant contribution is likely to come from uranium production centers such as Eastern Europe and Asia, which are not included in the capabihty projections (27). The remaining shortfall between fresh production and reactor requirements is expected to be filled by several alternative sources, including excess inventory drawdown. These shortfalls could also be met by the utili2ation of low cost resources that could become available as a result of technical developments or pohcy changes, production from either low or higher cost resources not identified in production capabihty projections, recycled material such as spent fuel, and low enriched uranium converted from the high enriched uranium (HEU) found in warheads (28). 

The homogeneous reactor experiment-2 (HRE-2) was tested as a power-breeder in the late 1950s. The core contained highly enriched uranyl sulfate in heavy water and the reflector contained a slurry of thorium oxide [1314-20-1J, Th02, in D2O. The reactor thus produced fissile uranium-233 by absorption of neutrons in thorium-232 [7440-29-1J, the essentially stable single isotope of thorium. Local deposits of uranium caused reactivity excursions and intense sources of heat that melted holes in the container (18), and the project was terrninated. 

Natural uranium consists mostly of and 0.711 wt % plus an inconsequential amount of The United States was the first country to employ the gaseous diffusion process for the enrichment of the fissionable natural uranium isotope. During the 1940s and 1950s, this enrichment appHcation led to the investment of several bUHon dollars in process faciHties. The original plants were built in 1943—1945 in Oak Ridge, Teimessee, as part of the Manhattan Project of World War II. 

Fluorine. Fluorine is the most reactive product of all electrochemical processes (63). It was first prepared in 1886, but important quantities of fluorine were not produced until the early 1940s. Fluorine was required for the production of uranium hexafluoride [7783-81 -5] UF, necessary for the enrichment of U (see DIFFUSION SEPARATION METHODS). The Manhattan Project in the United States and the Tube Alloy project in England contained parallel developments of electrolytic cells for fluorine production (63). The principal use of fluorine continues to be the production of UF from UF. ... 

For decades, fluorine was a laboratory curiosity and it was studied mainly by mineral chemists. As is often the case, it was coincidence and not planned research that gave rise to fluorine chemistry. The development of the organic chemistry of fluorine is a direct consequence of the Manhattan Project in order to build nuclear weapons, the isotopic enrichment of natural uranium into its radioactive isotope was needed. For this purpose, the chosen process involved gas diffusion, which required the conversion of uranium into gas uranium hexafluoride (UFs) was thus selected. In order to produce UFe gas on a large scale, fluorhydric acid and elemental fluorine were needed in industrial quantities. This was the birth of the fluorine industry. 

During the early years of the Second World War, Emmett directed an important National Defense Research Committee project at Hopkins that involved the use of adsorbents in gas masks to remove poison gases. In 1943 he became a division chief in the Manhattan Project, dealing with enrichment by diffusion of uranium isotopes for use in nuclear weapons. From 1945 until his death he was a consultant to the Atomic Energy Commission on peacetime uses of atomic power. 

Fuel enrichment. All practicable enrichment processes require the uranium to be in the form of a gas. UFg, which readily sublimes (p. 1269), is universally used and, because fluorine occurs in nature only as a single isotope, the compound has the advantage that separation depends solely on the isotopes of uranium. The first, and until recently the only, large-scale enrichment process was by gaseous diffusion which was originally developed in the Manhattan Project to produce nearly pure U for the first atomic bomb (exploded at Alamogordo, New Mexico,... 

The principal U.S. projects of this type are research at U.S. DOE s Los Alamos Laboratory, which uses UFg vapor, and work by U.S. DOE s Livermore Laboratory and a joint venture of Avco Everett Research Laboratory, Inc., and Exxon Nuclear Company, which use uranium metal vapor. The two groups [J2, T3] using uranium metal vapor reported production of milligram quantities of partially enriched uranium in 1975. Avco and Exxon applied for a license to build a pilot plant to demonstrate their process in the mid-1980s. 

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