Radioisotope production using highly enriched target encapsulation materials

Abstract

An enclosure for producing radioisotopes from material to be irradiated within a thimble guide tube of a nuclear reactor core is provided. The enclosure is constructed of enriched material and defines a cavity therein. The cavity of the enclosure is configured to contain the material to be irradiated. A target assembly for producing synthetic radioisotopes and a method for producing pharmaceutical radioisotopes using the target assembly are also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority under 35 U.S.C. Section 120 to U.S. patent application Ser. No. 18 / 049,343, filed Oct. 25, 2023, entitled "PRODUCTION OF RADIOISOTOPES WITH HIGHLY ENRICHED TARGET ENCLOSURE MATERIAL," the contents of which are incorporated herein by reference in their entirety.

[0002] Producing pharmaceutical radioisotopes requires inserting the target material into an enclosure and exposing the enclosure to a neutron flux for a specific irradiation cycle time. However, currently available enclosures may require long-term storage in spent fuel pools until the target carrier components and target material contained therein can be safely handled and / or transported to another location for processing / disposal. Issues related to safety and transportation logistics contribute to the cost of producing pharmaceutical radioisotopes and can limit the availability of radiation therapy. There is a need to produce the desired radioisotopes without requiring extensive downtime after irradiation. Summary of the Invention [Problem to be solved by the invention]

[0003] The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed herein, but is not intended to be a complete description. A complete understanding of the various embodiments disclosed herein can be gained by taking the entire specification, claims, and abstract as a whole. [Means for solving the problem]

[0004] In various aspects, an enclosure for producing radioisotopes from material to be irradiated within a thimble guide tube of a nuclear reactor core is disclosed. In some aspects, the enclosure is constructed of enriched material and defines a cavity therein. In other aspects, the cavity of the enclosure is configured to contain the material to be irradiated.

[0005] In various embodiments, a target assembly for producing synthetic isotopes is disclosed. In some embodiments, the target assembly includes an enclosure defining a cavity and a material to be irradiated disposed within the cavity of the enclosure. In certain embodiments, the enclosure includes an outer wall composed of a condensed material. In other embodiments, the material to be irradiated comprises a precursor of a first radioisotope.

[0006] In various embodiments, methods for producing pharmaceutical radioisotopes using a target assembly are disclosed. In some embodiments, the method includes inserting the target assembly into a thimble guide tube, irradiating the target assembly with a neutron flux, and removing the irradiated target assembly from the thimble guide tube to produce one or more pharmaceutical radioisotopes. In certain embodiments, the target assembly includes an enclosure and at least one material to be irradiated disposed within the enclosure. In other embodiments, the enclosure is comprised of a concentrated material.

[0007] These and other objects, features, and characteristics of the present disclosure, as well as the method of operation and function of the associated elements of construction, and combination of parts and economies of manufacture, will become more apparent from a consideration of the following description and appended claims, all of which are incorporated herein by reference in their entirety, when read in conjunction with the accompanying drawings. Like reference numerals refer to corresponding parts in the various drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the embodiments disclosed herein. [Brief explanation of the drawings]

[0008] The various aspects described herein, together with their objects and advantages, will be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

[0009] [Figure 1] FIG. 1 is a partial cross-sectional view of a nuclear reactor core in accordance with at least one non-limiting embodiment of the present disclosure.

[0010] [Figure 2] FIG. 2 is a schematic cross-sectional view of an enclosure according to at least one non-limiting embodiment of the present disclosure.

[0011] [Figure 3] FIG. 3 illustrates concentrated material irradiation results showing changes in activity levels, according to at least one non-limiting embodiment of the present disclosure.

[0012] [Figure 4] FIG. 4 illustrates concentrated material irradiation results showing changes in activity levels, according to at least one non-limiting embodiment of the present disclosure.

[0013] [Figure 5] FIG. 5 illustrates concentrated material irradiation results showing changes in activity levels, according to at least one non-limiting embodiment of the present disclosure.

[0014] Corresponding reference characters indicate corresponding parts throughout the various views. The exemplifications set forth herein illustrate various aspects of the present disclosure in one form, and such exemplifications are not to be construed as limiting the scope of the aspects disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0015] Certain exemplary embodiments of the present disclosure will be described to provide a general understanding of the principles of the compositions, functions, manufacture, and use of the compositions and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the compositions, articles, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. Features shown or described with respect to one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be within the scope of the present disclosure.

[0016] References herein to "various examples," "several examples," "one example," "one example," etc., mean that a particular feature, structure, or characteristic described in connection with that example is included in that example. Thus, the appearances of phrases such as "in various examples," "in several examples," "in one example," and "in one example" in various places throughout this specification do not necessarily all refer to the same example. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more examples. Thus, a particular feature, structure, or characteristic illustrated or described in connection with one example may be combined, in whole or in part, without limitation, with features, structures, or characteristics of one or more other examples. Such modifications and variations are intended to be included within the scope of the present examples.

[0017] In the following description, like reference characters in the drawings indicate like or corresponding parts. It should also be understood that in the following description, terms such as "front," "rear," "left," "right," "upper," "lower," "top," "bottom," etc. are used for convenience only and are not to be construed as limiting terms.

[0018] As used herein, the term "enriched material" refers to material that, prior to exposure to an intense radiation source, contains at least one stable isotope in an amount greater than that normally found in nature. As used herein, the term "isotopically pure" refers to enriched material with a single isotope at a level of greater than 98 mol%, greater than 99 mol%, greater than 99.99 mol%, or about 100 mol%. As used herein, the term "inert material" refers to material that does not participate in chemical and / or nuclear reactions in a nuclear reactor or auxiliary neutron generator environment.

[0019] Throughout this specification, the terms "short half-life" and "short-lived radioisotopes" are used for half-lives on the order of days. Throughout this specification, the terms "relatively long half-life" and "long-lived radioisotopes" are used for half-lives on the order of weeks, months, or years.

[0020] Pharmaceutical radioisotopes can be synthetically produced by irradiating and / or bombarding a target material with a constant neutron flux over a specific irradiation period. For example, pharmaceutically useful lutetium-177 is a beta emitter with a relatively short half-life of about 6.7 days. Over an irradiation period of at least 4 days, a target material based on ytterbium-176 can be synthetically produced with approximately 5x10 13 neutrons / cm 2 By bombarding a neutron flux of -s, lutetium-177 can be produced. Other pharmaceutical radioisotopes, such as actinium-225, can also be produced by neutron irradiation. Upon irradiation, compounds comprising pharmaceutical radioisotopes, such as water-soluble salts, can be incorporated into suspensions and / or solutions in preparation for administration.

[0021] In a neutron activation process, material to be irradiated is contained within an enclosure to form a target assembly, which is exposed to and removed from a neutron-rich environment to provide a desired neutron dose. For example, FIG. 1 illustrates a cross-sectional view of a nuclear reactor core 1 including a fuel assembly 1a according to at least one non-limiting embodiment of the present disclosure. The fuel assembly 1a can deliver neutron flux toward a tubular guide thimble disposed therein. The interior volume of the guide thimble is accessible through a bottom penetration 1b. During operation of the nuclear reactor core 1, a target assembly can be inserted through the bottom penetration 1b, placed within the guide thimble of the fuel assembly 1a, and exposed to a neutron-rich environment to deliver neutron flux to the material to be irradiated contained within the enclosure to produce a desired radioisotope. Once the desired irradiation period has elapsed and / or the material to be irradiated has captured the desired neutron dose, the irradiated material assembly is extracted from the guide thimble and processed to extract the desired radioisotope of the material to be irradiated from the enclosure.

[0022] Currently available enclosures may be made from materials found in nuclear reactor components, such as 304L stainless steel, 316L stainless steel, and Inconel 718. However, exposure of these material compositions of currently available enclosures to a neutron-rich environment can result in the formation of radioactive isotopes with relatively long half-lives, e.g., on the order of at least one year. As a result, these irradiated enclosures may require long periods of underwater storage in pools to reach a low and / or safe activity level that is safe enough for workers to handle. Thus, using currently available enclosures to contain target materials can pose safety hazards to workers and their environment, complicating the shipping logistics, handling, and / or recycling of irradiated enclosures. Furthermore, the long storage times required for these irradiated enclosures can create resource allocation challenges due to competing radiation sources requiring storage, such as spent fuel assemblies. Thus, various aspects of the present disclosure provide various methods and apparatus for irradiating target materials without producing undesirable long-lived radioisotopes, thereby avoiding the logistical issues associated with producing synthetic radioisotopes.

[0023] Referring now to FIG. 2 , a cross-sectional view of an enclosure 100 for producing radioisotopes from irradiated material 10 within thimble guide tubes of a nuclear reactor core is shown, in accordance with at least one non-limiting embodiment of the present disclosure. In some examples, the cross-sectional outer shape of the enclosure 100 may be approximately the same as or slightly smaller than the inner diameter of the thimble guide tubes of the nuclear reactor core. For example, the enclosure 100 may be configured in a generally cylindrical tubular shape having an outer diameter of about 0.3 inches, about 0.25 inches, about 0.2 inches, or about 0.15 inches. In particular examples, the enclosure 100 includes an outer wall 100a having an outer diameter and an inner diameter. The enclosure 100 may optionally include an inner layer 100b having an outer diameter and an inner diameter. Other configurations of the enclosure 100 are also contemplated by the present disclosure. For example, in some embodiments, the cross-sectional outer shape of the enclosure 100 may be configured as a hexagonal shape, a rectangular shape, or any other closed polygonal shape.

[0024] In various examples, the enclosure 100 defines a cavity therein. The cavity of the enclosure 100 is configured to contain the irradiated material 10. For example, if the irradiated material 10 is in the form of a cylindrical slug, the cavity may be configured with a cylindrical cross-sectional shape that is approximately the same as or slightly larger than the cylindrical slug. In some examples, the inner diameter of the outer wall 100a defines the cross-sectional shape of the cavity. In examples where the enclosure 100 includes an optional inner layer 100b, the inner diameter of the inner layer 100b defines the cross-sectional shape of the cavity.

[0025] In various examples, the enclosure 100 is constructed of enriched material. In some examples, the enriched material may include precursors of short-lived neutron-activated radioisotopes with half-lives of less than one week, less than five days, or less than one day. In particular examples, the enclosure 100 may be configured to have a short half-life when exposed to neutron flux. For example, a portion of the material in the enclosure 100 that is susceptible to neutron capture may be limited to precursors of short-lived radioisotopes. An enclosure 100 having this configuration may provide the advantage of minimizing downtime before shipping and / or handling after a period of neutron flux irradiation, e.g., the time required to generate medically useful radioisotopes at a given neutron flux, without compromising worker and / or environmental safety. In particular examples, the outer wall 100a of the enclosure 100 may be constructed of enriched material.

[0026] Additionally, the material properties of the enclosure 100 may be configured to reliably contain the irradiated target. For example, the outer wall 100a of the enclosure 100 may include an enriched material in combination with a chemically separable alloy material to optimize mechanical properties, such as strength and / or toughness, and / or chemical properties, such as corrosion resistance. This configuration is particularly advantageous for extending the life of the enclosure 100 if the enclosure 100 is inadvertently exposed to external stresses or if the enclosure 100 is intended to be reused. In some examples, the enclosure 100 comprises an alloy material that is a precursor to a short-lived radioisotope. In a particular example, the enclosure 100 is composed of a specific isotope of an alloy material, such as a specific isotope of copper and / or nickel. Thus, the composition of the enclosure 100 may be configured to provide the benefits of a short half-life upon irradiation without compromising the structural integrity of the enclosure 100 required to securely contain the irradiated material 10, thereby avoiding the safety, logistical, and / or economic issues associated with employing conventional irradiated material assemblies to produce synthetic radioisotopes.

[0027] The enriched material may be configured as an isotopically pure material. For example, the enriched material may be configured as a precursor for a particular beta-emitting radioisotope having a known half-life. In some examples, the enclosure 100 may include isotopically pure enriched nickel and / or copper. In particular examples, the enclosure 100 may include nickel-64, copper-63, or copper-65. Other configurations are contemplated by the present disclosure. For example, in some embodiments, the enriched material may be configured as a precursor for an alpha-emitting radioisotope, such as an isotope of lead, thallium, and / or bismuth.

[0028] Because isotopically pure enriched material does not contain multiple isotopes of a given element, irradiating it with a constant neutron flux can produce a specific radioisotope of that element with a predetermined activity level and / or decay mode. For example, irradiating an enclosure 100 containing enriched copper-65-based material produces copper-66, which undergoes beta decay with a half-life of less than one hour. Regarding specific activity, Figures 3-5 show the theoretical specific activities (units: curies / g) of nickel-65, copper-64, and copper-66 as a function of time following irradiation of nickel-64, copper-63, or copper-65, respectively. Thus, the composition of enclosure 100 can be configured to provide predictable decay behavior, thereby facilitating optimization of the logistics involved in handling the irradiated assembly after irradiation.

[0029] Because copper-64, copper-66, and nickel-65 have emerged as effective radiopharmaceuticals for cancer treatment, an enclosure 100 constructed of copper-63, copper-65, or nickel-64 can itself be a source of medical radioisotope when irradiated by a neutron flux, while also providing a housing for the desired irradiated material 10. When an enclosure 100 containing one of these enriched materials is used to produce lutetium-177, an activated form of the enriched material is produced within the timeframe of the irradiation period associated with the production of lutetium-177, resulting in a second pharmaceutical radioisotope with significant activity levels. For example, as shown in Figures 3-5, a 5x10 13 neutrons / cm 2 By irradiating nickel-64, copper-63, or copper-65 under a constant neutron flux of -s for an irradiation period of about four days, about one day, or less than one day, the theoretical maximum specific activity of the radioisotopes produced from nickel-64, copper-63, or copper-65 can be achieved. Thus, incorporating enclosure 100 comprising nickel-64, copper-63, or copper-65 in a process for producing lutetium-177 can increase the amount and / or variety of medical radioisotopes produced compared to processes using conventional enclosures without significantly changing the process parameters.

[0030] The present disclosure also provides a target assembly for producing synthetic radioisotopes. The target assembly includes an enclosure and a material to be irradiated disposed within a cavity of the enclosure. The target assembly enclosure is similar in many respects to other enclosures described elsewhere in this disclosure, and for the sake of brevity, it will not be described in detail again here. In various examples, the enclosure includes an outer wall constructed of an enriched material. In some examples, the enclosure may be constructed of an alloy of the enriched material. In some examples, the enclosure may include multiple layers surrounding a cavity. The target assembly enclosure may be constructed similarly to the enclosure 100 described above. Thus, the target assembly enclosure may be configured to securely contain the material to be irradiated and be inserted into a thimble guide tube of an operating nuclear reactor core without becoming a long-lived radioisotope. Furthermore, the enriched material of the enclosure may be constructed as an isotopically pure material so that its decay behavior after an irradiation period is predictable. For example, the enriched material may be based on nickel-64, copper-63, and / or copper-65. In this manner, the target assembly enclosure may be configured to minimize and / or optimize the time between irradiation and handling of the irradiated target assembly without the post-irradiation safety and logistical issues associated with conventional enclosures.

[0031] In various examples, the target material of the target assembly includes a precursor of a first radioisotope, and the cavity is configured to surround the target material. The first radioisotope may be a short-lived radioisotope and / or a medical radioisotope. For example, the target material may be a precursor of lutetium-177 and / or actinium-225. In one example, the target material may be configured as one or more slugs having a cross-sectional shape smaller than or approximately the same as the internal cavity defined by the enclosure. In a configuration in which the target material is a slug, the length of each slug may be less than half the length of the internal cavity defined by the enclosure. Thus, multiple target materials having this configuration may be disposed within the enclosure. Thus, by containing irradiated targets including precursors of lutetium-177 and / or actinium-225 within an enclosure constructed of nickel-64, copper-63, and / or copper-65, the process of producing synthetic radioisotopes can provide multiple pharmaceutical radioisotope product streams without requiring multiple irradiation cycles and / or multiple target assemblies.

[0032] In some examples, the irradiated material and the concentrated material of the enclosure may be separated by a layer of inert material. The layer of inert material provides a barrier to physical and / or chemical interaction between the irradiated material and the enclosure, facilitating their separation during any post-irradiation processing. Because synthetic radioisotopes begin to decay without an appropriate radiation source, delays after extraction of the target assembly during the neutron activation process may result in a lower activity level of the desired radioisotope upon arrival at its final destination, particularly in the case of short-lived pharmaceutical radioisotopes. In this manner, a target assembly configured with a layer of inert material may maintain a boundary between the irradiated material and the enclosure during the irradiation cycle, thereby optimizing the activity level available for the pharmaceutical radioisotope and / or reducing the time required for preparation for shipment.

[0033] As described herein, a target assembly including an irradiated target material and an enclosure composed of enriched material may be incorporated into a method for producing radioisotopes. For example, a method for producing pharmaceutical radioisotopes may include inserting a target assembly into a thimble guide tube, irradiating the target assembly with a neutron flux, and withdrawing the irradiated target assembly from the thimble guide tube to produce one or more pharmaceutical radioisotopes. In some examples, the enriched material before irradiation may include nickel-64, copper-63, and / or copper-65. In one example, the irradiated target material comprises lutetium-177 and / or actinium-225. In one example, the method includes transporting the one or more pharmaceutical radioisotopes within one week, five days, three days, two days, one day, or the same day after withdrawal of the target assembly. The method for producing radioisotopes may optionally include post-processing the target assembly after withdrawal of the target assembly. For example, chemical treatment and / or mechanical separation may be performed on one or more pharmaceutical radioisotopes to facilitate their transport or administration.

[0034] As discussed elsewhere in this disclosure, in processes for producing synthetic radioisotopes, target assemblies may be composed of various combinations of irradiated target materials and concentrated materials to provide multiple product streams and / or short half-life enclosures. Thus, the irradiated target materials and / or irradiated enclosures of a target assembly used in the production of pharmaceutical radioisotopes may each be composed of one or more pharmaceutical radioisotopes at the time of irradiation and / or extraction. Thus, as described above, the use of target irradiation assemblies in methods for producing pharmaceutical radioisotopes may increase process flexibility and / or reduce downtime of irradiated enclosures, thereby avoiding logistical and / or safety issues associated with conventional enclosures.

[0035] Various aspects of the present disclosure include, but are not limited to, those listed in the following numbered paragraphs:

[0036] Item 1 - An enclosure for producing radioisotopes from material to be irradiated within a thimble guide tube of a nuclear reactor core. The enclosure is comprised of an enriched material. The enclosure defines a cavity therein, the cavity of the enclosure configured to contain the material to be irradiated.

[0037] Item 2 - An enclosure as described in item 1, wherein the enriched material has a short half-life when exposed to neutron flux.

[0038] Item 3—An enclosure according to item 2, wherein the enclosure has a shortened half-life when exposed to neutron flux.

[0039] Item 4—The enclosure of any one of items 1 to 3, wherein the enriched material is isotopically pure.

[0040] Item 5 - The enclosure of any one of items 1 to 4, wherein the concentrated material comprises a precursor of a beta emitter.

[0041] Item 6 - The enclosure of any one of articles 1 to 5, wherein the enrichment material comprises at least one of nickel-65, copper-64, and copper-66.

[0042] Item 7 - The enclosure of any one of items 1 to 6, wherein the concentrated material comprises an alloy.

[0043] Item 8 - An enclosure according to any one of items 1 to 7, wherein the enclosure is made up of multiple layers.

[0044] Item 9 - The enclosure of any one of items 1 to 8, wherein the enclosure comprises an outer wall constructed from a condensing material.

[0045] Item 10 - A target assembly for producing a synthetic radioisotope, the target assembly comprising: an enclosure defining a cavity therein; and a material to be irradiated disposed within the cavity of the enclosure. The enclosure is comprised of a condensed material. The material to be irradiated comprises a precursor of a first radioisotope.

[0046] Item 11 - The target assembly of item 10, wherein the enriched material comprises a precursor of a second radioisotope, and the second radioisotope is a short-lived radioisotope.

[0047] Item 12 - The target assembly of any one of items 10 to 11, wherein the enriched material comprises an isotopically pure metal material.

[0048] Item 13 - The subject assembly of item 12, wherein the isotopically pure material comprises at least one of nickel-64, copper-63, and copper-65.

[0049] Item 14 - The subject assembly of any one of items 10 to 13, wherein the concentrated material comprises an alloy.

[0050] Item 15 - The subject assembly of any one of items 10 to 14, wherein a layer of inert material is disposed between the condensed material and the cavity.

[0051] Item 16 - A method for producing pharmaceutical radioisotopes using a target assembly, the method comprising: inserting the target assembly into a thimble guide tube; irradiating the target assembly with a neutron flux; and removing the irradiated target assembly from the thimble guide tube to produce one or more pharmaceutical radioisotopes. The target assembly comprises an enclosure and at least one material to be irradiated disposed within the enclosure. The enclosure is comprised of a concentrated material.

[0052] Item 17 - The method of item 16, wherein the enriched material comprises nickel-64, copper-63, and / or copper-65.

[0053] Item 18 - The method of any one of items 16 to 17, wherein the irradiated target material of the irradiated target assembly comprises lutetium-177 and / or actinium-225.

[0054] Item 19 - The method of any one of items 16 to 18, wherein each of the irradiated target material and enclosure of the irradiated target assembly is independently configured with one or more pharmaceutical radioisotopes, respectively.

[0055] Various features and characteristics are described herein to provide an understanding of the composition, structure, manufacture, function, and / or operation of the present disclosure, including the disclosed methods and systems. It will be understood that various of these features and characteristics of the present disclosure described herein may be combined in any suitable manner, whether or not such combinations of features and characteristics are explicitly described herein. The inventors and applicants expressly intend that such combinations of features and characteristics be included within the scope of the disclosure described herein. Accordingly, the claims may be amended to recite any combination of features and characteristics explicitly or inherently described or explicitly or inherently supported herein. Furthermore, applicants reserve the right to amend the claims to affirmatively disclaim any features or characteristics that may exist in the prior art, even if those features or characteristics are not explicitly described herein. Accordingly, any such amendments will not add new matter to the specification or claims, but will comply with the requirements of the specification, specification sufficiency, and additional matter.

[0056] With respect to the appended claims, those skilled in the art will understand that the operations described therein may generally be performed in any order. Additionally, while various operational flows are depicted in a sequential order, it should be understood that various of these operations may be performed in orders other than those depicted, or may be performed simultaneously. Examples of such alternative orders include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, concurrent, reversed, or other variations, unless the context dictates otherwise. Furthermore, terms such as "in response to," "related to," and other past tense adjectives are generally not intended to exclude such variations, unless the context dictates otherwise.

[0057] The words "comprise" (and any form of "comprise," such as "comprised" or "comprising"), "have" (and any form of "have," such as "had" or "having"), "include" (and any form of "include," such as "included" or "comprising"), and "contain" (and any form of "contain," such as "contained" or "containing") are open-ended linking verbs. Thus, a method or system that "comprises," "has," "includes," or "contains" one or more features and / or characteristics has, but is not limited to, having only, those one or more features and / or characteristics. Similarly, an element of a composition, coating, or process that "comprises," "has," "includes," or "contains" one or more features and / or characteristics has, but is not limited to having only those one or more features and / or characteristics, and may have other features and / or characteristics.

[0058] As used herein, including the claims, the grammatical articles "a," "an," and "the" are intended to include "at least one" or "one or more," unless expressly stated otherwise. Accordingly, articles are used herein to refer to one or more than one (i.e., "at least one") of the grammatical object of the article. As an example, "a component" means one or more components, and thus, it is conceivable that one or more components may be employed or used in the practice of the described compositions, coatings, and processes. That being said, it should be understood that the absence of the terms "at least one" or "one or more," when used in some cases, should not be construed as limiting the object of the grammatical articles "a," "an," and "the" to one. Furthermore, unless the context dictates otherwise, the use of a singular noun includes the plural, and the use of a plural noun includes the singular.

[0059] As used herein, unless otherwise noted, all numerical parameters should be understood to be prefaced and modified in all instances by the word "about." Such numerical parameters have the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of such parameters. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter set forth herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0060] Numerical ranges recited herein include all subranges subsumed within the recited range. For example, a range of "1 to 10" includes all subranges between (and including) the recited minimum value of "1" and the recited maximum value of "10," i.e., all subranges with a minimum value of 1 or greater and a maximum value of 10 or less. Also, all ranges recited herein include their endpoints. For example, a range of "1 to 10" includes the endpoints 1 and 10. Each maximum numerical limitation recited herein is intended to include all subranges subsumed therein, and each minimum numerical limitation recited herein is intended to include all subranges subsumed therein. Accordingly, applicants reserve the right to amend this specification, including the claims, to expressly recite any subranges subsumed within any explicitly recited range. All such ranges are inherently set forth herein.

[0061] As used herein, particularly in reference to layers, the terms "on," "upon," "over," and variations thereof (e.g., "coated on," "formed on," "deposited on," "provided on," "located on," etc.) mean coated, formed, deposited, provided, or positioned on the surface of a substrate, but not necessarily in contact with the surface of the substrate. For example, a layer "coated" on a substrate does not exclude the presence of another layer or other layers, of the same or different composition, between the coated layer and the substrate. Similarly, a second layer "coated" on a first layer does not exclude the presence of another layer or other layers, of the same or different composition, between the coated second layer and the coated first layer.

[0062] While particular examples of the present disclosure have been described above for purposes of illustration, it will be apparent to those skilled in the art that many changes in the details of the present disclosure can be made without departing from the disclosure as defined in the appended claims.

Claims

1. 1. An enclosure for producing radioisotopes from material to be irradiated within a thimble guide tube of a nuclear reactor core, comprising: the enclosure is constructed of a condensed material; the enclosure defining a cavity therein; the cavity of the enclosure is configured to contain the material to be irradiated; Enclosure.

2. the enriched material has a shortened half-life when exposed to neutron flux; The enclosure of claim 1 .

3. the enclosure has a reduced half-life when exposed to neutron flux; The enclosure of claim 2 .

4. the enriched material is isotopically pure; The enclosure of claim 1 .

5. the condensed material comprises a precursor of a beta emitter; The enclosure of claim 4.

6. the enriched material comprises at least one of nickel-64, copper-63, and copper-65; The enclosure of claim 5 .

7. the concentrated material comprises an alloy; The enclosure of claim 1 .

8. The enclosure is constructed from multiple layers. The enclosure of claim 1 .

9. the enclosure comprises an outer wall constructed from the condensed material; The enclosure of claim 1 .

10. 1. A target assembly for producing synthetic radioisotopes, comprising: The target assembly comprises: an enclosure defining a cavity, the enclosure including an outer wall comprised of a condensing material; a material to be irradiated disposed within the cavity of the enclosure, the material comprising a precursor of a first radioisotope; A target assembly comprising:

11. the enriched material comprises a precursor of a second radioisotope; the second radioisotope is a short-lived radioisotope; The target assembly of claim 10.

12. the enriched material comprises an isotopically pure metal material; The target assembly of claim 10.

13. the isotopically pure metal material comprises at least one of nickel-64, copper-63, and copper-65; The target assembly of claim 12.

14. the concentrated material comprises an alloy; The target assembly of claim 12.

15. a layer of inert material disposed between the condensed material and the cavity; The target assembly of claim 10.

16. 1. A method for producing a pharmaceutical radioisotope using a target assembly, comprising: The method comprises: inserting the target assembly into a thimble guide tube, the target assembly comprising an enclosure and at least one target material disposed within the enclosure, the enclosure being comprised of a condensed material; irradiating the target assembly with a neutron flux; removing the irradiated target assembly from the thimble guide tube and producing one or more pharmaceutical radioisotopes. method.

17. the enriched material comprises nickel-64, copper-63, and / or copper-65; 17. The method of claim 16.

18. the irradiated target material of the irradiated target assembly comprises lutetium-177 and / or actinium-225; 17. The method of claim 16.

19. the enclosure and the irradiated target material of the irradiated target assembly each comprise a pharmaceutical radioisotope; 17. The method of claim 16.

Images