MXPA98007540A - Separation of isotopes by ionization for processing of nucl fuel materials - Google Patents

Abstract

The present invention relates to: Improved apparatus and processing methods are provided which involve the selective ionization of a fed material and the separation of ionized and non-ionized species. The introduction of a chemical material is provided to produce the selective transition to a non-ionized and / or solid or liquid state of part of the feed. The process offers high total throughput because the ionized and non-ionized species are in balance with the ot

Description

SEPARATION OF ISOTOPES BY IONIZATION FOR THE PROCESSING OF NUCLEAR FUEL MATERIALS This invention relates to improvements in, and relating to processing, particularly, but not exclusively, to the processing of nuclear fuel materials and materials involved in the nuclear fuel industry . The production and recycling of fuel-grade nuclear fuel and associated materials involve long and complex processes. For example, starting from the mined uranium ore, in general terms, the process involves taking the ex-grade material and gradually converting and enriching it until it is in a form and is of an adequate degree to produce fuel pellets. The intermediate stages in the global process route also form the starting point for the production of a variety of other materials. The basic stages in the overall process are the concentration of initial uranium oxides such as uranyl nitrate hexahydrate; a denitration stage to convert the material to U03; a reduction stage to convert U03 to U02; a hydrofluorination step to form UF4; an additional fluorination step to produce UF6; an enrichment process by physical or chemical means; and the conversion of UF6 into its enriched form to ceramic grade U02 which is in a suitable form to be formed into fuel pellets.

Recycling spent fuel similarly involves a series of chemical and physical steps to separate the different fission products from spent fuel and to increase the concentration of 235U in the material to a stage where it can again be used as a fuel by separating other components present in the fuel used. The complexities of these processes are also present in other production processing lines involved in. or they refer to, fuel cycles, such as thorium, plutonium and gadolinium among other materials. The production of uranium metal, unenriched, for example for use in Magnox reactors. it also involves complex processing. Extensive or involved processing is also found in the production of other materials outside the immediate nuclear fuel field. For example, the production route commonly used for titanium, niobium and rhodium metal. among others, it involves converting the compounds containing the metal into a halide form followed by its decomposition from the halide form to the metal. Substantial processing plants, in terms of their size, decapitated investment! and operating costs, are necessary to carry out the stages involved in all these processes. There are also concurrent problems that come from various processes and their requirements. For example, processes involving fluorination involve a complex and dangerous electrolysis process to produce the required fluoride. The present invention helps provide an alternative processing path for many processes and / or a process for converting materials into more useful forms and / or a process for recycling materials, together with apparatuses, to achieve the processes. In accordance with a first aspect of the invention, we provide a process comprising the steps of: a) providing a feeding, feeding consisting of mixed components; b) convert the feed into a plasma or ionized form; c) providing at least one component in at least one partially ionized form and at least one different component in at least one partially un-ionized form; d) contain the plasma / ions in a magnetic field; and e) separating the ionized components from the non-ionized components. The desired component can be extracted from a mixture of isotopes and / or elements of a metallic and non-metallic nature. The separation can be complete or partial. Provision is foreseen for feeding in a nitrogen-containing compound, but the provision of food in a form containing fluorine is particularly preferred. Feeding material consisting of uranyl nitrate, uranium hexafluoride, plutonium nitrate, thorium nitrate, spent uranyl nitrate, spent uranium hexafluoride or mixtures thereof, may represent suitable feedstocks. Other suitable feedstocks include spent nuclear fuel, uranium tetrafluoride and other metals in halide form, such as titanium tetrachloride. These materials can be in the hydrated form. The mixed components may consist of two or more different elements; two or more different isotopes of the same element; different elements together with isotopes of one or more of these elements; or compounds and / or mixtures of compounds that incorporate different elements, different isotopes or different isotopes and different elements and reference should be made in this application that the term components include all these possibilities, among others, unless otherwise stated. The feed can be introduced into the magnetic field as a gas, liquid, solid or mixture of states. A gas supply to the magnetic field is preferred. The feed can be introduced to the plasma generation means as a gas, liquid, solid or mixture of states. The feed can be introduced to the ionization media as a gas, liquid, solid or mixture of states. A gas feed to the ionization means is preferred, particularly when a plasma generator is also not provided. The feed can be provided in gaseous form by boiling and / or evaporating and / or sublimating a solid or liquid initial feed. The conversion to gaseous state can be effected by an oven, microwave heater or other form of heating medium. Preferably the gas is introduced before the ionization. Preferably all, or substantially all, of a given component is ionized. Preferably all, or substantially all, of a given component is not ionized. Preferably some or all of the metal elements present in the feed are ionized. The ionization of metallic elements with an atomic weight greater than 90 is particularly preferred. Preferably some or all of the non-metallic elements in the feed are non-ionized. Preferably some elements with an atomic weight below 90, more preferably below 70 and ideally below 60, are left in the non-ionized form. It is particularly preferred that elements such as uranium and / or plutonium and / or thorium and / or gadolinium are ionized. It is preferred that elements such as hydrogen and / or fluorine and / or oxygen and / or nitrogen are not ionized. Preferably the boron is not ionized. Preferably the fission products are non-ionized. The ionization of the components can be caused by the temperature of the plasrria. Additionally or alternatively the ionization of the components can be caused by the interaction of the components with high-energy electrons produced by electronic cyclotron resonance.

The degree of ionization and / or ionized components can be controlled by the energy input and / or residence time in the electronic cyclotron resonance unit. Preferably the ionization is controlled by the energy input level. The energy input level can be controlled by controlling the plasma temperature. Preferably the energy input is not selective between components of the power supply. In this way all the components of the feed are preferably raised to the same energy level. Preferably, the ionized and non-ionized feed components are in equilibrium with one another for the prevailing conditions. The feed material can be converted to a gas and fed to an RCE unit for ionization. A furnace heater or evaporator can be used to convert the solid or liquid feed to the gaseous / vapor form. Therefore, in a particular embodiment, the plasma can convert the feedstocks to discrete atoms and the electronic cyclotron resonance can subsequently result in at least partial ionization, preferably of a selective nature. 3 i The feed can be supplied in molecular form and converted to discrete atoms and / or elemental forms by the generation of plasma and / or ionization means and / or heating means. Conversion to discrete atoms and / or elemental forms can result in partial ionization of one or more of the resulting species. Therefore, a feed of uranyl nitrate hexahydrate can be converted to U, N and H (discrete atomic forms), along with N2 and 02 (elemental forms), as well as U + (ionized species). Preferably, the feed is provided in molecular form and selectively separated as discrete atoms and / or elemental forms of discrete ionized atomic forms and / or elemental forms. This makes the technique applicable to a wider variety of materials that are possible with elemental feeding and separation in elemental form or molecular feeding followed by separation in molecular form. The temperature of the plasma can be controlled to provide selective ionization of the components in the desired manner. Therefore, plasma can ionize some components in the feed but leave other non-ionized components, such as fission products and / or non-metal elements. Preferably, said plasma is provided from 2726.9 to 4426.9 ° C. Preferably, said plasma is generated by means of microwave or radio frequency. Preferably the plasma in the generator is operated between 1000 and 10000 Pa. A value of 2000 +/- 10% is preferred. Additionally or alternatively, the residence time of the feed into the plasma before separation can be controlled to provide selective ionization of the components in the desired form.

Preferably the feed is introduced into the magnetic field of concentration in a non-ionized form.

Preferably the partial ionization process occurs within the magnetic field in a non-charged gas. The gas can have the molecular and / or atomic form. The magnetic field can be configured to define a cylindrical active volume in which plasma / ions are processed.

Preferably the plasma / ions pass along the axis of this containment area of the plasma generation and / or ionization media to the next separation step. Preferably the separation of the ionized and non-ionized components is affected by removing the non-ionized component of the plasma, more preferably as a gas. The non-ionized components can be pumped out of the ionized component. The ionized component is contained, and therefore restricted, by the magnetic field. The separation of the ionized from the non-ionized components can be carried out in a number of stages. Preferably the steps are discrete one from the other. The stages can be Separate one from the other by a baffle provided with an opening. Preferably the opening is completely within the magnetic field containment area. Preferably one or more of the steps are operated at different pressures for one or more of the other steps. The level of pressure can be maintained by the level of pumping used. Preferably the pressure in one or more stages near the inlet is greater than one or more away from the inlet. Preferably the pressure decreases for each zone in relation to the preceding stage closer to the entrance. Preferably the pressure in each stage is from 30% to 60% of the preceding stage, progressing far from the entrance. Preferably, three stages are provided. Each stage can be between 0.05 and 2 m in length. Preferably the first stage is operated between 10 and 50 Pa. A level of 40 Pa +/- 10% is preferred. Preferably the second stage is operated between 5 and 20 Pa.

A level of 16 Pa +/- 10% is preferred. Preferably the third stage is operated between 2 and 10 Pa. A level of 7 Pa +/- 10% is preferred. The separated uncharged components can be recycled for subsequent use and / or subjected to further processing. This may include additional selective ionization and / or selective processing to separate different components. The components charged separately are preferably still contained in a magnetic field. The separated charged components may be subjected to further processing including selective, deionized deionization followed by selective ionization; or other selective processing to separate different components. The charged components can be cooled, and / or discharged to provide a liquid and / or solid non-charged product. The charged components can be recovered in a grid, plate, electrode or earth grounded or loaded with the product itself. The loaded components can be recovered in a container or container. A reservoir of the liquid can be provided in the container or container. The temperature conditions can be controlled to purify the recovered components by evaporating impurities. The impurities can be vaporized in the form of compounds with the recovered metal and / or component. Vaporization of halides is envisaged. The recovered charged components can be removed periodically or continuously from the recovery point. The method may comprise the additional step of introducing a chemical material, preferably at a controlled kinetic energy level and contacting it with the rest of the charged components, the energy level of the charged component and the chemical material being such that it results a component or particle not loaded. The component can still be present as a gas. The chemical material may consist of a material selected to give the desired non-charged particle and / or final product, such as oxygen or an inert gas as the chemical material. The chemical material can be added at a temperature between -173.1 ° C and 1726.9 ° C and particularly -173.1 ° C to 226.9 ° C. The component and chemical material can be combined in the resulting particle. An oxide represents a potential form. The temperature of the combined form can be controlled so as to provide the particle in the desired form. A temperature of 2226.9 ° C is preferred with uranium so that uranium is present as gaseous U02 as the main form. A step can be provided in which an additional chemical material is added to the non-charged component so as to reduce the level of kinetic energy to a stage where a solid product is produced. Alternatively or additionally, the reduction of kinetic energy level can be provided by impacting the uncharged component on a surface, preferably a cold surface. The reduction of the level of kinetic energy for the uncharged particle can occur very rapidly so as to avoid undesired intermediate equilibrium forms of the product. A transition period of < 2 ms is preferred. The additional chemical material may be the same or different from the previously added chemical material. Preferably the process product is the desired compound, element or isotope and preferably to the desired degree. Ceramic grade metal oxide is a particularly preferred product of the process although metal can also be produced in this manner. Products of uranium, plutonium, thorium and in addition to MOX can be produced by controlling the process conditions.

According to a second aspect of the invention, we provide separation apparatuses, said apparatuses comprising: a) a plasma / ion generator; b) means for selectively ionizing a feed material of mixed components; c) means that generate magnetic field producing a magnetic field to contain the plasma / ions; and d) means for removing components not charged from the magnetic field. The feeding can be provided as a solid, liquid or gas. You can use an oven, heater, microwave source. evaporator or other heating means for heating and / or vaporizing and / or sublimating and / or gasifying and / or evaporating the feed. Preferably the plasma / ions are generated by microwave or radio frequency heating. The ionization of the components can be caused by the plasma temperature. Preferably the plasma is heated to between 2726.9 and 4426. 9 ° C and more preferably 3726.9 ° C + or -10%. Preferably the output of the plasma / ion generator is between and 20 and 40 mm radius. The plasma generator can act as the means for selectively ionizing the mixed components of the feedstock. Alternatively or additionally, high energy electron collisions produced by electronic cyclotron resonance means may provide the means to selectively ionize the mixed component feed material. The feed can feed the RCE as a molecular and / atomic gas. Preferably the degree of ionization and / or ionized components is controlled by the energy input level. The energy level can be controlled by the temperature. Preferably the feed is excited uniformly. Preferably the energy input is not selective among the components present. Preferably the partial ionization / partial ionization of the resulting feed is in equilibrium for the prevailing conditions. The magnetic containment field can be axially aligned. Preferably the magnetic field generating means comprises one or more solenoids. Preferably, magnets are provided in an annular or cylindrical assembly. In this way, a containment area is defined by the magnetic field, preferably of cylindrical configuration. Preferably the magnetic field is provided as a containment field more preferably in an axial alignment. Field strengths in excess of 0.075 tesla or in excess of 0.1 tesla can be used for this purpose. Preferably the feed is introduced to the magnetic field before ionization.

Preferably the separation is affected by removing the non-ionized component of the plasma. Preferably the means for removing the non-loaded components comprises a pump unit. Preferably the charged components are retained in the magnetic field. The non-ionized components can be separated from the feed in one or more stages. Preferably one or more outlets through which the non-ionized components are removed, are provided at each stage. Preferably the stages are separated from one another by a bypass element. Preferably the bypass is provided with a circular opening through which the feed passes. Preferably the openings in the branches are axially aligned. The diameter or size of the opening in one or more leads may be larger than the opening in one or more leads closer to the feed inlet than the opening. Preferably the openings increase in diameters sequentially away from the feed inlet. Preferably the opening has a radius that substantially corresponds to the radius of the plasma / ion stream at that distance from the entry. Preferably the aperture radius is the same or less than 10% larger than the radius of the plasma / ion stream at that location. Preferably the radius of one or more openings is approximately proportional to the fourth root of the distance of the inlet or the plasma generating nozzle.

Preferably the opening radius is smaller than the radius of! containment area defined by the magnetic field at that location. The apparatus can also provide addition means for a chemical material to the rest of the process stream. Preferably the chemical material introduced is oxygen or an inert gas. It is particularly preferred that the added chemical material provide an extinguishing and / or cooling action to the remaining components. Preferably the chemical material on contact with the remaining components converts them from a charged to an uncharged phase. More preferably the component is still retained in the gaseous state after this change. In a particularly preferred embodiment the addition of oxygen is used as the chemical material. Preferably this is introduced from -173.1 ° C to 2226.9 ° C to give a combined temperature of about 2226.9 ° C in combination with the charged component. At this temperature, for example, U is retained as a non-charged gas mainly in the form of U02. An additional means can be provided for the addition of an additional chemical material. Preferably this addition converts the process stream from a gaseous to a solid state. Alternatively or additionally, the reduction of the level of kinetic energy can be provided by impacting the uncharged component on a surface, preferably a cooled surface. The conversion is preferably obtained very quickly in reality to restrict the formation of any state in equilibrium that intervenes. Preferably the product is a ceramic grade fuel material, such as U02. According to a third aspect of the invention, we provide a process comprising the steps of: a) providing a feeding, feeding consisting of mixed components; b) converting the feed into a plasma / ionized form; c) providing at least one component in at least one partially ionized form and at least one component a component in at least partially un-ionized form; d) contain the plasma / ions in a magnetic field; and e) separating the ionized components from the non-ionized components; and further comprising converting at least some of the ionized components or separate components to an uncharged form. The component can be converted to the non-charged form by reducing its level of kinetic energy, ie by condensing it. The component can be converted to an uncharged form by impacting it on a surface, preferably a cold surface. - The component can be converted to the uncharged form by the addition of a chemical material. A combination of one or more of these can be used.

Preferably the chemical material is added to a level! of predetermined kinetic energy so that it gives the desired non-charged shape. More preferably the uncharged form is in a gaseous form. The conversion of one, or a portion of one or more components to the uncharged form is envisaged, while retaining one or more other components, or a portion of one or more other components and / or a portion of the first component. components in the loaded form. The addition of the chemical material, or the addition of additional chemical material in an additional step, can be such that it reduces the level of kinetic energy to a stage where a solid product is produced. The added chemical material can react with the component or it can simply reduce its level of kinetic energy. The component can be produced in an elementary or composite form. Preferably, the transition from an uncharged gaseous particle to a solid product occurs very rapidly. A transition period of less than 2 more is preferred. The separation of uranium and fluorine from a feed of uranium hexafluoride has a potential use. Additionally the separation of uranium from uranyl nitrate hexahydrate and other forms of feeding is foreseen. Additional processing and subsequent use of uncharged components separated from the loaded components are foreseen. The production or recycling of fluorine using this route is the particularly preferred form. This aspect of the invention, of course, can include any of the aspects or possibilities discussed in this application, including those that relate to ion / plasma generation, its containment, the manner of separation and others. According to a fourth aspect of the invention we provide the separation apparatus, the apparatus comprising: a) a plasma / ion generator; b) means for selectively ionizing the feed material of the mixed components; c) magnetic field generating means that produce a magnetic containment field for the plasma / ions; d) means for removing components not charged from the magnetic field; and e) means for converting at least some of the separated charged components to the non-loaded form. The component can be converted to the non-charged form by reducing its level of kinetic energy, that is, condensing it. The component can be converted to the non-charged form by impacting it on a surface, preferably a cooled surface. The component can be converted to the uncharged form by the addition of a chemical material. A combination of one or more of these can be used.

The chemical material can be introduced in a single stage or in multiple stages. When using multiple stages it is preferred that the different inputs are separated from one another along the direction of the path of the process stream. Therefore, the first means for effecting a transition from a charged to an uncharged state can be provided and additional second steps can be provided to convert the uncharged component to the solid state or the desired chemical composition. The production of both elementary and composite forms of the desired product is foreseen. Of course, other features of the apparatus or methods discussed in this application may be equally relevant to this aspect. According to a fifth aspect of the invention we provide separate components, materials, compounds, elements or isotopes according to the first and / or third aspects of the invention and / or using the apparatus of the second and / or fourth aspect of the invention and / or additional processed forms thereof. The separate components can be different elements presented in the feed. Therefore, the separation of uranium from fluorine is foreseen, since the separation of other elements is foreseen, with the separation of other elements present in one or more given compounds. The production of metal oxides of ceramic grade suitable for the use of fuels is foreseen.

The degree of separation between the components can be substantially complete or only partial. These processes are envisaged in which a proportion of the component in the feed is extracted as uncharged components in the process while the majority of that component continues in the product stream produced from the charged components. Since then, the first or second stream of uncharged products can constitute the utility and aid for the separate component as well as the final product of the loaded component. According to a sixth aspect of the invention, we provide a pellet of fuel, fuel barrel or fuel assembly or part of a nuclear reactor incorporating the product or an additional processed product, of any of the first to fifth aspects of the invention . Various embodiments of the invention will now be described by way of example only, and with reference to the accompanying drawings in which: Figure 1 illustrates schematically a first embodiment of the invention; Figure 2 illustrates a phase diagram for uranium, oxygen, nitrogen and hydrogen; Figur 3 is a phase diagram for U +, UO, U02 and U03; Figure 4 schematically illustrates a partial view of a second embodiment of the invention; Figure 5 illustrates schematically a third embodiment of the invention; Figure 6 illustrates schematically a fourth embodiment of the invention. The techniques of the present invention offer versatile processing systems that can be successfully employed with a variety of materials and conditions of departure and produce a variety of product materials, states and shapes. Feeding of nitrate hexahydrate As illustrated in Figure 1, the feed to be processed is introduced according to arrow 2. In this particular example the feed material consists of a feed liquor of uranyl nitrate hexahydrate. The feed liquor passes through a plasma generator (4) which rapidly heats the feed liquor to about 3726.9 ° C. The plasma generator (4) can be a microwave or plasma generator of the RF type. The plasma temperature control can be easily provided. The conductive solenoids in the arrangement (6) produce a magnetic field of high intensity whose lines of force are schematically represented (8). By the stage at which the power is ionized within the plasma generator, it is easily within the confines of this magnetic field. The conductive solenoids are set to produce an intensity field in excess of 0.1 tesla.

As a consequence of the plasma generator (4) the feed material enters the chamber (12) at a high temperature. At this temperature the uranyl nitrate hexahydrate decomposes in its component atoms. This allows the processing of the feedstock according to its individual atomic formation instead of needing an elemental feedstock or processing the feeds only according to the differences between the molecules that are ionized or not subsequently. As can be seen from the phase diagram provided in Figure 2 at 3726.9 ° C and under the type of conditions experienced in the chamber (12), the uranium atoms, U +, line 20 are charged. Conversely at this temperature the volume of nitrogen, oxygen and hydrogen are uncharged atoms or molecules as seen in the lines of Figure 2 representing nitrogen, N, line 22; oxygen, O, line 24, and hydrogen, H, line 26; all the ions are in gaseous form. Selective ionization occurs as a result of the overall energy level of the system. Therefore, the species that are ionized under the prevailing conditions and the species that are not, are determined by the state of equilibrium for those species under those conditions. The selective ionization obtained is therefore stable and durable allowing the subsequent procedure to be carried out without time pressure.

If the energy is only selectively introduced to certain species within the system, then selective ionization can be obtained. However, collisions between ionized and non-ionized species, in such a case, result in energy transfer that can result in the ionization of previously un-ionized species and / or the discharge of previously ionized species. In this case, a separation must be carried out very quickly or the selective nature will decay before any significant selectivity obtained in the separation. In the equilibrium plasma of the present system the collisions are not only tolerable, they are convenient to ensure a uniform distribution of the energy input through the plasma. However, collisions have no detrimental effect, for example, as a collision between a U + ion and an F atom, under the prevailing equilibrium conditions result in a U + ion and an F atom as the most likely result. probable. The equilibrium conditions do not provide enough energy for the collision to result in electron transfer and ion discharge. The potential to allow collisions also means that the plasma can be operated in a relatively dense state allowing a significant material passage. If collisions have to be avoided, then it is convenient to reduce the probability of collisions to a density of ions and atoms as low as possible.

As charged particles the uranium ions are contained by the magnetic field and are passed through the superconducting solenoids (6). The non-charged nature of the nitrogen, oxygen and hydrogen atoms allows it to move freely, not chained by the magnetic field and consequently it can be "pumped" out of the chamber (12), current (14). Vacuum pumps can be used for this purpose. Subsequent cooling of the stream (14) allows these materials to fall back into a recombined equilibrium giving normally N2, 02 and H20 and nitrogen oxides. As a consequence of this aspect of the process the uranium has been separated from the other elements by forming the uranyl nitrogen hydrate feed. Subsequent processing of the separated uranium can be conducted as required. The strong uniform field present in the portion (16) of the process strictly confines the uranium ions. By introducing an oxygen feed (42) to the portion (44) of the process, the U ions are extinguished. By controlling the extinction, a reduction in temperature can be made to 2226.9 ° C. At this temperature, as can be seen in Figure 3, the predominant form of the material is U03 gas in an uncharged state, although other forms of uranium oxide are probably present to a lesser degree. Again a balanced system is provided.

If desired, by applying an additional extinguishing stream (52) the temperature can be further reduced and the uranium oxide can be rapidly taken from a gaseous state to a solid state in the form of a ceramic powder, location (54) . This one comes out as current (58). The product may be subjected to further subsequent processing, for example, to improve it to fuel grade materials. The process, therefore, provides a single modular unit for the conversion of uranyl nitrate hexahydrate feed into uranium dioxide powder. A similar result can be obtained with other compounds and / or feed mixtures of the feed compounds. A single modular unit corresponding to this process, which has an overall length of approximately 10 m and an active region of around 1 m in diameter, can process between 50 and 200 Kg / hr of feed uranium. The residence time within the unit is very low, in the order of 10 ms. This time is a reflection of the theoretical average speed at which the uranium ions travel at 3726.9 ° C, that is 6 x 102 cm / s. 'Spent fuel feed In addition to converting natural uranyl nitrate hexahydrate into fuel grade materials the technique has application in other processing areas including the reprocessing of products from the fuel rods used to extract the desired components. The fuel gas consists mainly of U03 powder in combination with several fission products, generally of less than an atomic weight of 60, low levels of 235U and plutonium. Processing this material in a nitrate liquor and introducing liquor to the process described before you can make the following separations. The application of the apparatus of Figure 1 once again in the initial chamber (12) following the generation of plasma, is ionized 235U, isotopes of plutonium and 238U (which forms the majority of the fuel). Most fission products, as well as N, H, O, remain in a non-ionized state and consequently are not restricted to the magnetic field. Pumping of these materials in stream (14) is then possible. The product stream (14) may be subjected to further processing, including an additional step or process steps according to this invention to separate components, isotopes or elements of interest from the other species in the stream. If it is possible to recover and / or subject the current of the product - (16) that remains in the magnetic field to further processing. The product stream (16) can be quenched as described above to produce a solid product. As for what refers to subsequent processing, the product can be subjected to conventional enrichment techniques. This can be used to properly separate the isotopes of 238U, 23SU and plutonium from one or the other as desired and thus achieve a reactor grade material. Titanium tetrachloride feed As illustrated in an alternative embodiment, the partial view, in Figure 4, the feed material can be provided with an additional system to provide or ensure the required ionization of the selected component or components. In this particular example, the feedstock consists of titanium tetrachloride and the desired product is titanium metal, but the technique is equally applicable to a wide range of feedstocks. In this unit the feed (2) passes through a plasma generator (4) and is contained in a magnetic field (8). The temperature of the plasma is such that the feedstocks are reduced to discrete atoms and can be partially ionized. In this way the feed then passes through an electronic cyclotron resonance unit (102) which causes the input of additional energy to the plasma due to the collision of the high energy electrons with the components. According to the appropriate phase diagrams and the energy level of collisions provided, as a consequence of the overall energy level of the system, certain components, in this case titanium, are ionized while others, chlorine, remain in a non-ionized form . The selective ionization is due to the balance states of the species between ionized and non-ionized, which prevail. The material then passes inside the chamber (12) where the uncharged chlorine can be removed from the magnetic field as process stream (14). Chlorine can be recycled to the first stages in the overall process involved in the production of titanium tetrachloride. The remaining component, titanium, and processing steps, can be treated as presented in Figure 1 or subjected to further processing. Production of uranium metal The technique in another mode, as illustrated in Figure 5, also offers a convenient production technique for uranium metal. It is equally applicable to recover other elements by separating other feeding materials into their constituent elements. The conventional techniques employ concentration type techniques, desnitration, reduction and hydrofluorination treated before, before the uranium fluoride is converted to the metallic form by reacting it with magnesium. On the other hand, the present process can offer a convenient way to separate the uranium metal from the uranyl nitrate hexahydrate feed.

The feed of uranyl nitrate hexahydrate (200) is introduced into the apparatus. The food consists elementally of uranium, nitrogen, oxygen and hydrogen. The plasma generator and microwave or RF type (202) can quickly subject the feed to a temperature of about 3726.9 ° C. Even with a short residence time, this is enough to break the feeding material into its discrete elementary forms and in many cases into discrete atoms. Therefore the feed is converted to U, N, N2, 02, H, etc., with some U +. The atomized feed is contained in the plasma, the plasma being contained in the magnetic field (204) generated by magnets (206). While the plasma itself may have caused partial ionization of some elements present, an electronic resonance atmosphere of cyclotrons (208) is provided to bring about the desired degree of ionization. The atmosphere (208) imparts energy to the electrons present within the plasma and the increasing energy of the electrons is such that energy is transferred upon colliding with the components of the feed. According to the equilibrium that can be applied to the species involved in the collision under the prevailing conditions, ionization occurs for some components, but not for others. The probability of ionization for the different parts of the feed varies in the manner discussed earlier. Therefore, uranium is ionized, for example, at a lower energy level of electron excitation than oxygen, hydrogen and the like. As a consequence, the time in which the process stream reaches the chamber (210) consists of the ionized and non-ionized components. The non-ionized components can be pumped out of the chamber (210) into the product stream (214) since they are not restricted by the magnetic field. The charged components, mainly uranium, continue in the process stream (212) with the plasma being contained by the additional magnets (216). The introduction of a chemical material (218) into the stream (212) effects the desired reaction or phase change in the charged components separately. By thus providing argon at a relatively low energy level, for example -173.1 ° C, the charged components can be converted to non-charged components and in the product form very rapidly due to the collision between the cold current (218) and the current ( 212). In the embodiment shown, this transition is shown to be affected by a step of introducing chemical materials, but also a first step is envisaged to convert the material from the charged to the uncharged form and a second to convert it from a gaseous form to an uha solid The inert nature of added gas provides cooling without the risk of chemical combination with uranium. Therefore, the uranium metal results.

The nature of the chemical material (218) and the level of energy to which it is added can be used to control the shape, structure and chemical composition of the product originating in the chamber (220) and in the product stream (224). Therefore, the introduction of oxygen could be used to convert uranium, for example, to U03 as an alternative for the careful control of the energy level with respect to the oxygen introduced or the introduction of the inert gas to reduce the uranium ions to forms of uranium metal. A similar process route can be used to produce uranium metal from uranium tetrafluoride produced during the hydrofluorination stage discussed above in relation to the extraction of uranium from primary sources. Processing of the first product stream (214) to use the elemental constituents is also envisioned. For example, in this case fluorine can be recovered from the stream for subsequent reuse in the previous stages of material processing. Feeding uranium hexafluoride In an alternative process using this technique, the feedstock (200) consists of uranium hexafluoride. Selective ionization of this feed leads to uranium ions and uncharged fluorine atoms. The separation of these in the chamber (210) leads to a uranium ion stream (212) and a fluorine stream (214). The subsequent production of uranium metal as a product (224) and the re-use of fluorine ier in the nuclfuel processing cycle or in other applications is possible. The application of these processes is particularly foreseen for the treatment of the exhausted stream leaving the chemical enrichment process treated before. The exhausted current contains uranium hexafluoride, the concentration of 235UF6 in which it is low, the 235UF6 is extracted as much as possible for further use, the vast majority of the uranium hexafluoride being 238UF6. Currently this material has no significant use and is stored as uranium hexafluoride for long periods. Uranium hexafluoride is relatively volatile and is not an ideal storage form. The present technique offers the possibility of taking this exhausted stream, or storage amounts of this product, and processing them to obtain useful materials. The released fluorine can be returned to the processing cycle to be reused, for example, and a new final product, uranium metal, is presented in a readily and conveniently stored form or available for use. Therefore, fluorine and spent U metal can be produced. By controlling the chemical species added to the uranium ions, for example during an extinction, other compounds can also be generated, for example, all the uranium nitrate, uranium carbide and uranium oxide products can be formed.

A further embodiment of the invention is illustrated schematically in Figure 6 by illustrating an additional apparatus. The description of the device will be made in relation to the separation of uranium from the uranium hexafluoride feed, but other applications can also be made for this device. The uranium hexafluoride feed liquor is introduced into the stream (300) as a vapor. The feed is rapidly converted to a plasma by a radio frequency plasma generator (302). The plasma generator operates at 2KPa in order to ensure the ionization levels essentially in equilibrium for the desired components of the feed due to high levels of collisions. The contact parts within the plasma generator can be formed from ceramic fluorides in order to give the physical properties necessary to withstand the conditions involved. The system can use copper surface that is cooled by contact with tubes containing water. The water flow is used to lower the temperature of the copper walls and cause the condensation of the uranium fluoride forms on the walls. This chemically and thermally insulates copper. Eventually, a state of equilibrium develops with a given thickness of uranium fluoride deposited on the wall. Therefore, a self-sharpening effect is provided. The generated plasma leaves the generator (302) through the nozzle (304) and is contained by the magnetic field, illustrated schematically (306). A nozzle with a radius of about 30mm is used to maintain the pressure inside the plasma generator (304) and to give the desired flow rate. When leaving the plasma of the generated one and when entering zone 1 (308) the plasma will expand causing the cooling. However, the work done against the magnetic field by the uranium ions will result in a partial overheating. If appropriate, additional energy can be introduced into the plasma during its subsequent progress through the apparatus to maintain the temperature at a level at which the desired components remain ionized. This energy can be provided by radio frequency. The desired selectivity based on equilibrium is therefore maintained. The beam of material leaving the plasma generator tends to detach as the distance of the plasma generator increases. The barriers (310, 312) that define the different zones take into account this expansion in their diameters of selected openings. The containment field is approximately 0.1 tesla of resistance. These levels can be provided by conventional electromagnets although superconducting magnets can be used. A magnetic field of this resistor confines the uranium ions to a radius of 180mm or follows a path distance of 3mm from the nozzle. The zones / stages each have 1mm in length. The radius of the expansion beam is approximately proportional to the fourth route of the distance traveled. Within zone 1 (308) the outlets (314) are provided to a vacuum pump, not shown. This allows the first waste streams to be extracted from the apparatus, the waste streams comprising unloaded material, mainly fluorine.

Aluminum can be used for waste stream lines. The pressure in zone 1 is about 13 Pa and during its path through that zone the fluorine pressure in the material beam is substantially reduced at that pressure. Excess fluoride is pumped out through the outlet (314) using commercially available pumps. The beam with reduced fluorine content then passes to zone 2 (316) through space (318) in barrier (310). The second zone (318) is operated at a lower pressure than the first, approximately 5 Pa and once the fluorine content in the beam is reduced towards this pressure as the material passes through the zone. The beam then passes into zone 3 (320) through space (322) in the barrier (312). Again this zone is operated at a pressure still less than about 2 Pa, with the excess fluorine being pumped out through the outlets (324). The fluoride beam significantly depleted then passes over the outlet (326) for subsequent handling.

The ionized gaseous uranium can be contacted with a grid of some description to discharge the charge and reduce the energy of the uranium to a state in which it is solid or liquid. The introduction of chemical materials to effect an extinction and / or cooling action can be considered. In this regard, the use of inert gases to cool the uranium may be preferred so that a chemical combination with the gases can not occur. As a result, metallic uranium arises. The uranium can be cooled sufficiently to provide it as a solid or alternatively it can be cooled only or partially to leave it in liquid form. The fluorine that remains in the uranium product stream (326) can easily be volatilized as a uranium fluoride, the volume of the uranium product and recycled. When the uranium is collected as a liquid the separation can be carried out conveniently in situ. UF volatilized will largely convert to UF6 that can be recycled. Similar separations are possible for UF4, TiCl and other metal halides. The provision for recovering the fluorine released from the liquid by gasification can be provided. Ceramic fluoride or graphite materials can be used to form the liquid recovery container. For a feeding of 12kg of uranium per hour, a fluoride feed of 5.7kg / hr arises. Of these 3.6kg / hr of fluorine it is expected to be pumped from zone 1; 1 .3kg / hr pumped from zone 2; 0.5kg / hr pumped from zone 3; and 0.3kg / hr remain in the uranium product stream (326). The degassing of fluorine from this product as U F3 and / or U F4 results in a pure uranium product, ie, with a fluorine content scale in parts per thousand. The different modalities established in the present being closely related to each other and it should be appreciated that the aspects dealt with explicitly with respect to one or more aspects or modalities can also be applied to the others.

Claims (37)

1. CLAIMS 1. A process that includes the steps of: a) providing a diet, the food consisting of mixed components; b) converting the feed into a plasma or ionized form; c) providing at least one component in at least one partially ionized form and at least one different component in at least one partially un-ionized form; d) containing the plasma / ions in a magnetic field; and e) separating the ionized components from the non-ionized components.
2. 2. A process according to claim 1, wherein the desired component is extracted from a mixture of isotopes and / or elements of a metallic and non-metallic nature.
3. 3. A process according to claim 1 or claim 2, wherein the feed is provided in gaseous form by boiling and / or evaporating and / or sublimating a solid or liquid feed.
4. 4. One processed according to any of claims 1 to 3, in which some or all of the metal elements present in the feed are ionized.
5. 5. A process according to claim 4, wherein the metallic elements with an atomic weight greater than 90 are ionized.
6. 6. A process according to any of claims 1 to 5, wherein the ionization of the components is caused by the temperature of the plasma and / or by the interaction of the components with high energy produced by electronic cyclotron resonance.
7. 7. A process according to any of claims 1 to 6, wherein the ionization is controlled by the energy input level.
8. 8. A process according to any of claims 1 to 7, wherein the energy input is not selective between the feed components.
9. 9. A process according to any of claims 1 to 8, wherein the ionized and non-ionized feed components are in equilibrium states for the prevailing conditions.
10. 10. A process according to any of claims 1 to 9, wherein the feed is provided in molecular form and selectively separated as discrete atoms.
11. 11. A process according to any of claims 1 to 10, wherein the feed is introduced into the magnetic containment field in non-ionized form.
12. 12. A process according to any of claims 1 to 11, wherein the separation of ionized and non-ionized components is effected by removing the non-ionized component of the plasma, while the ionized component is restricted by the magnetic field.
13. 13. A process according to any of claims 1 to 12, wherein the separation is carried out in a plurality of stages and in which the stages are operated at different pressures from one another, the pressure in one or more stages near the entry being greater than one or more away from the entrance.
14. 14. A process according to claim 13, wherein three stages are provided, the first zone is operated at between 10 and 50 Pa, the second zone is operated at between 5 and 20 Pa and the third zone is operated between 2 and 10 Pa.
15. 15. A process according to any of claims 1 to 14, wherein the separated uncharged components are recycled for subsequent use and / or subjected to further processing.
16. 16. A process according to any of claims 1 to 15, wherein the charged components are cooled and / or discharged to provide a liquid or solid non-charged product.
17. 17. A process according to any of claims 1 to 16, wherein the method comprises the additional step of introducing a chemical material, at a given kinetic energy level, and contacting it with the remaining charged components, the the level of kinetic energy of the charged component and the chemical material being such that an uncharged component or particle results.
18. 18. A method according to claim 17, wherein the components and additional chemical material are combined in the resulting particle.
19. 19. Separation apparatus, the separation apparatus comprising: a) a plasma / ion generator; b) means for selectively ionizing a feed material of mixed components; c) means that generate magnetic field producing a magnetic field to contain the plasma / ions; and d) means for removing components not charged from the magnetic field.
20. 20. Apparatus according to claim 19, wherein the plasma / ions is generated by microwave or radio frequency heating.
21. Apparatus according to claim 19 or claim 20, wherein a furnace, heater, microwave source or evaporator is used to heat and / or vaporize the feed.
22. 22. Apparatus according to claim 19, 20 or 21, in which the partial ionization / partial ionization of the resulting feed is in equilibrium.
23. 23. Apparatus according to any of claims 19 to 22; wherein the means for removing uncharged components comprises a pumping unit.
24. 24. Apparatus according to any of claims 19 to 23; in which the non-ionized components are separated from the feed in one or more stages.
25. 25. Apparatus according to claim 24, in which the steps are separated from one another by a bypass element provided with an opening.
26. 26. Apparatus according to claim 25, wherein the opening has a radius substantially corresponding to the plasma / ion current radius at that distance from the inlet and wherein the radius of one or more of the openings is approximately proportional fourth root of the entrance distance or nozzle of the plasma generator.
27. 27. Apparatus according to any of claims 19 to 26; wherein the apparatus further provides means for the addition of a chemical material to the remaining process stream to provide an extinguishing and / or cooling action to the remaining components.
28. 28. A process comprising the steps of: a) providing a feeding, consisting of mixed components; b) converting the feed into a plasma / ionized form; c) providing at least one component in at least one partially ionized form and at least one component a component in at least partially un-ionized form; d) contain the plasma / ions in a magnetic field; and e) separating the ionized components from the non-ionized components; and further comprising converting at least some of the ionized components or separate components to an uncharged form.
29. 29. A process according to claim 28, wherein the component is converted to the non-charged form by reducing its level of kinetic energy.
30. 30. A process according to claim 28 or 29, wherein the component is converted to an uncharged form by impacting it on a surface, preferably a cooled surface.
31. 31. A process according to any of claims 28 to 30, wherein the component is converted to an uncharged form by the addition of a chemical material.
32. 32. A process according to claim 31, wherein the chemical material is added to a predetermined kinetic energy level so as to give the desired non-charged form in a gaseous form.
33. A process according to claim 31 or 32, wherein the addition of the chemical material, or the addition of the additional chemical material in an additional step, is such that it reduces the level of kinetic energy to a stage where it is produced a solid product
34. 34. Separation apparatus, the separation apparatus comprising: a) a plasma / ion generator; b) means for selectively ionizing the feed material of the mixed components; c) magnetic field generating means that produce a magnetic containment field for the plasma / ions; d) means for removing components not charged from the magnetic field; and e) means for converting at least some of the separated charged components to the non-loaded form.
35. 35. Separation apparatus according to claim 34, wherein the chemical material is introduced in multiple stages, the various entrances being separated one from the other along the direction of the current path of the process.
36. 36. Separated components, materials, elements or isotopes according to any of the re vindicates is 1 to 35.
37. 37. A pellet of fuel, fuel rods or fuel assembly for a nuclear reactor incorporating the product, or a product additional processed according to any of claims 1 to 36. RESU M EN Improved processing apparatus and methods are provided, which imply the selective ionization of a fed material and the separation of ionized and non-ionized species. The introduction of a chemical material is provided to produce the selective transition to a non-ionized and / or solid or liquid state of part of the feed. The process offers high total yield because the ionized and non-ionized species are in equilibrium with each other.