Micro reactor fuel sleeve assembly

Abstract

A reactor fuel rod for use in a nuclear reactor is disclosed. The reactor fuel rod comprises a sleeve defining a longitudinal axis. The sleeve includes a first end and a second end. The reactor fuel rod further includes a first end cap mechanically connected to the first end of the sleeve and a second end cap mechanically connected to the second end of the sleeve. The second end cap is configured to slide along the longitudinal axis relative to the sleeve. The reactor fuel rod further includes a fuel compact positioned between the first end cap and the second end cap within the sleeve.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the priority and benefit of U.S. Patent Application No. 18 / 163,415, filed on February 2, 2023, and titled "MICRO - REACTOR FUEL SLEEVE ASSEMBLY", under 35 U.S.C. § 120. The content of the same application is incorporated herein by reference in its entirety.

[0002] (Government Contract) The present invention was made with government support under Contract No. DE - NE0009050 awarded by the Department of Energy. The government has certain rights in the present invention.

Background Art

[0003] This disclosure relates to micro - reactors and fuel loading into micro - reactors.

Summary of the Invention

[0004] In a general aspect, this disclosure provides a nuclear reactor fuel rod for use in a nuclear reactor. The nuclear reactor fuel rod includes a sleeve defining a longitudinal axis. The sleeve includes a first end and a second end. The nuclear reactor fuel rod further includes a first end cap mechanically connected to the first end of the sleeve and a second end cap mechanically connected to the second end of the sleeve. The second end cap is configured to slide along the longitudinal axis with respect to the sleeve. The nuclear reactor fuel rod further includes a fuel compact disposed between the first end cap and the second end cap within the sleeve.

[0005] In another embodiment, the disclosure provides a reactor fuel rod for use in a nuclear reactor. The reactor fuel rod includes a tube defining a longitudinal axis. The tube includes a first end and a second end. The reactor fuel rod further includes a first end cap mechanically connected to the first end of the tube and a second end cap including an extraction tool interface feature. The second end cap is mechanically connected to the second end of the tube. The second end cap is configured to move along the longitudinal axis relative to the tube. The reactor fuel rod further includes a plurality of fuel pellets positioned between the first end cap and the second end cap within the tube.

[0006] In yet another embodiment, the Disclosure provides a method for inserting reactor fuel into a reactor using reactor fuel rods. The method includes connecting a first end cap of a reactor fuel rod to a first end of a sleeve of the reactor fuel rod; inserting a fuel pellet into the sleeve; and connecting a second end cap of the reactor fuel rod to a second end of the sleeve so that the fuel pellet is positioned between the first and second end caps within the sleeve. The method further includes connecting an extraction tool to an extraction tool interface feature of the reactor fuel rod; and positioning the reactor fuel rod in the reactor using the extraction tool. [Brief explanation of the drawing]

[0007] Novel features in various embodiments are described in detail in the attached claims. In the drawings, where multiple drawings share the same or corresponding reference numerals, the embodiments described can be best understood by referring together with the following description and the attached drawings, both in terms of configuration and operation.

[0008] [Figure 1] Figure 1 is a perspective view of an exemplary core of a microreactor according to at least one aspect of the present disclosure.

[0009] [Figure 2]Figure 2 is a perspective view of a plurality of unit cells within the reactor core of Figure 1, according to at least one aspect of this disclosure.

[0010] [Figure 3] Figure 3 is a perspective view of a plurality of unit cells within the reactor core of Figure 1, according to at least one aspect of this disclosure.

[0011] [Figure 4] Figure 4 is a perspective view of a fuel sleeve assembly according to at least one aspect of the present disclosure.

[0012] [Figure 5] Figure 5 is a perspective view of the fuel sleeve assembly of Figure 4 according to at least one aspect of the present disclosure, in which the sleeve is transparent.

[0013] [Figure 6] Figure 6 is a detail view showing one end of the fuel sleeve assembly of Figure 5, according to at least one aspect of the present disclosure.

[0014] [Figure 7] Figure 7 is a detail view showing one end of the fuel sleeve assembly of Figure 5, according to at least one aspect of the present disclosure.

[0015] [Figure 8] Figure 8 is a side view of the fuel sleeve assembly of Figure 5 according to at least one aspect of the present disclosure.

[0016] [Figure 9] Figure 9 is a side view of the fuel sleeve assembly of Figure 5 according to at least one aspect of the present disclosure.

[0017] [Figure 10] Figure 10 is a cross-sectional view of the fuel sleeve assembly of Figure 5 according to at least one aspect of the present disclosure.

[0018] [Figure 11]Figure 11 is a cross-sectional view of the fuel sleeve assembly of Figure 5 according to at least one aspect of the present disclosure.

[0019] [Figure 12] Figure 12 is a perspective view of the sleeve of the fuel sleeve assembly of Figure 5 according to at least one aspect of the present disclosure.

[0020] [Figure 13] Figure 13 is a perspective view of the fuel sleeve assembly according to at least one aspect of the present disclosure, with the sleeve shown transparently.

[0021] [Figure 14] Figure 14 is a detailed view showing one end of the fuel sleeve assembly of Figure 13 according to at least one aspect of the present disclosure.

[0022] [Figure 15] Figure 15 is a detailed view showing one end of the fuel sleeve assembly of Figure 13 according to at least one aspect of the present disclosure.

[0023] [Figure 16] Figure 16 is a side view of the fuel sleeve assembly of Figure 13 according to at least one aspect of the present disclosure.

[0024] [Figure 17] Figure 17 is a side view of the fuel sleeve assembly of Figure 13 according to at least one aspect of the present disclosure.

[0025] [Figure 18] Figure 18 is a cross-sectional view of the fuel sleeve assembly of Figure 13 according to at least one aspect of the present disclosure.

[0026] [Figure 19] Figure 19 is a side view of the fuel sleeve assembly according to at least one aspect of the present disclosure, with the sleeve shown transparently.

[0027] [Figure 20] Figure 20 is a side view of the fuel sleeve assembly of Figure 19 according to at least one aspect of the present disclosure.

[0028] [Figure 21] Figure 21 is a cross-sectional view of the fuel sleeve assembly of Figure 19 according to at least one aspect of the present disclosure.

[0029] [Figure 22] Figure 22 is a cross-sectional view of the fuel sleeve assembly of Figure 19 according to at least one aspect of the present disclosure.

[0030] [Figure 23] Figure 23 is a side view of a fuel sleeve assembly according to at least one aspect of the present disclosure, in which the sleeve is transparent.

[0031] [Figure 24] Figure 24 is a side view of the fuel sleeve assembly of Figure 23 according to at least one aspect of the present disclosure.

[0032] [Figure 25] Figure 25 is a cross-sectional view of the fuel sleeve assembly of Figure 23 according to at least one aspect of the present disclosure.

[0033] [Figure 26] Figure 26 is a cross-sectional view of the fuel sleeve assembly of Figure 23 according to at least one aspect of the present disclosure.

[0034] [Figure 27] Figure 27 is a perspective view of a fuel sleeve assembly showing an external extraction tool interface feature according to at least one aspect of the present disclosure.

[0035] [Figure 28] Figure 28 is a cross-sectional view of the fuel sleeve assembly of Figure 27 according to at least one aspect of the present disclosure.

[0036] [Figure 29] Figure 29 is a perspective view of a fuel sleeve assembly showing an external extraction tool interface feature according to at least one aspect of the present disclosure.

[0037] [Figure 30] Figure 30 is a cross-sectional view of the fuel sleeve assembly of Figure 29 according to at least one aspect of the present disclosure. [Modes for carrying out the invention]

[0038] Various specific details are provided to provide a full understanding of the overall structure, function, manufacture, and use of the embodiments described herein and shown in the accompanying drawings. Known functions, parts, and elements are not described in detail so as not to obscure the embodiments described herein. Readers of this specification will understand that the embodiments described herein are non-limiting examples, and therefore, the specific structural and functional details disclosed herein are representative and illustrative. Modifications and alterations may be made without departing from the claims. Furthermore, it should be understood that terms such as “up,” “down,” “front,” “rear,” “left,” “right,” “upward,” and “downward” are for convenience only and should not be interpreted as limiting terms.

[0039] Furthermore, the use or application of the explanatory examples is not limited to the structural and arrangement details of the components described in the accompanying drawings and specification. The explanatory examples may be implemented or incorporated in other embodiments, variations, and modifications, and may be implemented or performed in a variety of ways. Moreover, unless otherwise noted, the words and expressions used herein have been selected for the convenience of the reader to illustrate the explanatory examples and are not intended to limit them. It should also be understood that one or more embodiments, expressions of embodiments, and / or examples described below can be combined with one or more other embodiments, expressions of embodiments, and / or examples described below.

[0040] For a micro reactor to operate, it requires fuel such as a large quantity of TRISO fuel compacts. Loading and unloading these fuel compacts individually is time-consuming and difficult. To ensure efficient and robust fuel supply, removal, and refueling of the reactor, a method for efficiently loading and unloading these fuel compacts is needed. Generally, micro reactors do not include fuel cladding. In this respect, since the fuel compacts are loaded as individual pieces, they must be loaded in a non-vertical direction to prevent damage from impact forces. This configuration makes it difficult to easily remove the fuel compacts during refueling or end-of-life processing.

[0041] One solution to this problem is to house the fuel using a retaining sleeve assembly or fuel sleeve assembly. This allows for an efficient and automated process not only during initial fuel loading but also during refueling and end-of-life removal. The fuel sleeve assembly includes a sleeve or tube, end caps for the ends of the sleeve, a fuel compact, one or more reflectors, and a biasing member. One of the end caps is provided with a retaining / removal tool interface feature, which allows for easy removal and / or replacement of the entire fuel sleeve assembly. Furthermore, the biasing member (e.g., a plenum spring) may be located inside or outside the end cap, and the design of the removal tool interface feature may include an external head or an internal cavity. Several configurations satisfying the above description are conceivable, some of which are described herein.

[0042] There are several advantages to using fuel sleeve assemblies. For example, applying fuel sleeve assemblies can minimize / optimize the time required for initial fuel loading, reloading, and end-of-life fuel removal from the reactor core. It may also be possible to develop automated processes for loading and unloading fuel sleeve assemblies. Without such fuel sleeve assemblies, the removal of spent fuel would be complex, time-consuming, and extremely costly, requiring the removal of fuel compacts one by one. Furthermore, without fuel sleeve assemblies, even a slight shift in the core could cause fuel compacts to become clogged or unable to be removed from the core, making the removal process even more difficult.

[0043] By using fuel sleeve assemblies, reactor fuel can be easily disposed of. For example, the entire fuel sleeve assembly can be housed in a long-term storage container. In at least one embodiment, fuel sleeve assemblies can also make it easier to separate high-level and low-level nuclear waste.

[0044] Figure 1 is a perspective view of an exemplary core 100 of a microreactor according to at least one aspect of the present disclosure. In this example, the microreactor uses heat pipes to transfer thermal energy from the core 100. Thanks to its solid-state design, the microreactor is inherently simpler, smaller, more reliable, and more transportable than conventional reactors. The number of moving parts within the core 100 is limited, and the required maintenance is minimal. Decay heat is removed by natural convection and radiative heat transfer.

[0045] Referring to Figure 1, the reactor core 100 may be assembled to include fuel 111 (e.g., rods or stacks) arranged to pass through a plurality of unit cells 102 and reactivity control unit cells 104, heat pipes 113, and reactivity control rods 115. Specifically, the fuel 111 may be arranged to pass through fuel channels of one or more unit cells 102, the heat pipes 113 may be arranged to pass through heat pipe channels of one or more unit cells 102, and the reactivity control rods 115 may be arranged to pass through reactivity control channels (not shown) of one or more reactivity control cells 104. In some non-limiting embodiments, the fuel 111 and heat pipes 113 are configured to extend over the length of the reactor core 100. In other non-limiting embodiments, the heat pipes 113 are configured to extend further beyond the length of the reactor core 100 to facilitate downstream external connections and / or equipment (e.g., power conversion systems, condensers, structural supports). This design allows the core 100 to be customized to any purpose and / or user preference, so that the core 100 can be changed according to customer needs. In the assembled core 100 design shown in Figure 1, the fuel 111 and heat pipes 113 can be individually configured to accommodate any specific power requirements and / or structural arrangement without altering the basic design of the core 100 or incurring any potential development risks.

[0046] Referring further to Figure 1, the reflector 106 may further include a plurality of control drums 108 configured to house neutron absorbers and reflectors. In the event of a malfunction in the reactor and / or power, the control drums 108 may rotate inward toward the core 100 so that absorbers that shut down the core 100 face inward. According to some non-limiting embodiments of Figure 1, the reflector 106 may further include a neutron shield and a gamma-ray shield configured to substantially surround the core 100 and internal components 102, 104, 111, 113, 115 of the core to further reduce radiation.

[0047] Referring again to Figure 1, the reactor core 100 may further include a plurality of reaction control rods 115 configured to be positioned through one of a plurality of reactivity control cells 104. For example, a reactivity control cell 104 may include reactivity control rods 115, or reactivity control channels similar to fuel channels and / or heat pipe channels, but is specifically configured to accommodate the reactivity control rods 115. Each reactivity control rod 115 may include a neutron absorber configured to slow and / or stop nuclear reactions within the reactor core 100 in an emergency. When a malfunction occurs in the reactor and / or power, the reactivity control rods 115 work together to prevent the reactor core 100 from reaching criticality or to stop the reactions.

[0048] Figures 2 and 3 show perspective views of a plurality of unit cells 102 within the reactor core 100 of Figure 1, according to at least one aspect of the present disclosure. The unit cells 102 are stacked along the length of the reactor core 100. The fuel sleeve assembly 200 is insertable into the fuel channels of the unit cells 102. The nuclear fuel sleeve assembly (e.g., fuel sleeve assembly 200) is compatible with a plurality of micro-reactors (e.g., sodium heat pipe micro-reactors). The nuclear fuel sleeve assembly enables the reactor to reach criticality and provides a cost-effective means for fuel removal and refueling.

[0049] As described above, several configurations are possible that satisfy the description of the fuel sleeve assembly. Figures 4 to 12 illustrate fuel sleeve assembly 200, Figures 13 to 18 illustrate fuel sleeve assembly 300, Figures 19 to 22 illustrate fuel sleeve assembly 400, Figures 23 to 26 illustrate fuel sleeve assembly 500, Figures 27 and 28 illustrate external extraction tool interface feature 668, and Figures 29 and 30 illustrate external extraction tool interface feature 768. There are other designs that could be used to describe the fuel sleeve assembly, but for the sake of brevity, they will not be described. Those skilled in the art will understand that new or similar fuel sleeve assembly designs can be created by substituting various components from various designs.

[0050] Figures 4–12 show the fuel sleeve assembly 200. Figures 4–7 are perspective views, Figures 8 and 9 are side views, and Figures 10 and 11 are cross-sectional views, all showing the fuel sleeve assembly 200 according to at least one aspect of the present disclosure. The fuel sleeve assembly 200 includes a sleeve 202 extending from a first end 204 to a second end 206 and defining a longitudinal axis 201. In at least one aspect, the sleeve is non-metallic, for example, a carbon fiber reinforced carbon sleeve. Non-metallic sleeves can minimize neutron interaction and maintain virtually unchanged core dimensions during reactor operation. Using metal cladding would make the reactor much larger, heavier, and / or more expensive.

[0051] Referring to Figures 5 to 9, the sleeve 202 is shown as transparent. The sleeve 202 houses and holds a first reflector rod 230, a plurality of fuel compacts 232, and a second reflector rod 234. For example, the first reflector rod 230, the plurality of fuel compacts 232, and the second reflector rod 234 are insertable into the sleeve along the longitudinal axis 201. In at least one embodiment, the fuel compacts 232 are TRISO pellets. The fuel sleeve assembly 200 includes a first end cap 210 and a second end cap 240 that prevent internal components within the sleeve 202 (e.g., the first reflector rod 230, the plurality of fuel compacts 232, and the second reflector rod 234) from coming out of the sleeve 202 during reactor operation. In at least one embodiment, the sleeve 202 prevents the fuel compacts from directly interacting with the reactor core 100.

[0052] Referring to Figures 8 and 10, the first end cap 210 is configured to hold the reflector rods 230, 234 and the fuel compact 232 within the sleeve 202. In at least one embodiment, the first end cap 210 has an inner portion 218 that is inserted into the first end 204 of the sleeve 202 along the longitudinal axis 201. The inner portion 218 is in contact with the first reflector rod 230. The first end cap 210 is mechanically connected to the sleeve 202. In at least one embodiment, the first end cap 210 is mechanically connected to the sleeve by a retaining pin 214 being inserted into a hole 212 provided in the sleeve 202 and the inner portion 218, the hole 212 being perpendicular to the longitudinal axis 201. For example, the hole 212 in the inner portion 218 may be provided such that the hole 212 coincides with the hole 212 in the sleeve 202 when the inner portion 218 is inserted. When the retaining pin 214 is positioned within the hole 212, the first end cap 210 may be held in place relative to the sleeve 202. The first end cap 210 may be mechanically connected to the sleeve 202 in various ways, one of which is a retaining pin connection. Another method is to screw the first end cap 210 onto the first end 204 of the sleeve 202.

[0053] In at least one embodiment, the first end cap 210 has a tapering portion 216 that reduces the end of the first end cap furthest from the fuel sleeve assembly 200. In at least one embodiment, the fuel sleeve assembly 200 is inserted into the reactor core 100 by the first end cap 210 entering the core 100. In this embodiment, the tapering portion 216 of the first end cap 210 allows the fuel sleeve assembly 200 to be easily aligned with the fuel channels of the reactor core 100 and to slide into the fuel channels.

[0054] Referring to Figures 9 and 11, the fuel sleeve assembly 200 has a second end cap 240 configured to hold reflector rods 230, 234 and a fuel compact 232. In at least one embodiment, the second end cap 240 is inserted into the second end 206 of the sleeve 202 along the longitudinal axis 201. The second end cap 240 is mechanically connected to the sleeve 202 and is configured to slide within the sleeve 202 along the longitudinal axis 201. In at least one embodiment, the second end cap 240 has a slot 254 cut into the second end cap 240 along the longitudinal axis 201, and the sleeve 202 has a hole 250 that penetrates the sleeve 202 perpendicular to the longitudinal axis 201. A retaining pin 252 is insertable into the hole 250 and the slot 254. In at least one embodiment, the retaining pin 252 is attached to the sleeve 202. Once the second end cap 240 is mechanically connected to the sleeve 202, the second end cap 240 can slide within the sleeve 202 over the length of the slot 254. The second end cap 240 may be mechanically connected to the sleeve 202 in a variety of ways, one of which is a retaining pin-slot connection.

[0055] The second end cap 240 has an end portion 242 that extends away from the second end cap 240 along the longitudinal axis 201. In at least one embodiment, a biasing member 260 (e.g., a spring such as a plenum spring, coil spring, or bevel spring) is attached to the end portion 242. In at least one embodiment, the biasing member 260 is made of carbon fiber. In at least one embodiment, when the fuel sleeve assembly 200 is outside the reactor, the fuel sleeve assembly 200 is in an incompressible configuration. For example, the second end cap may not apply compressive force to the internal components of the sleeve 202. In at least one embodiment, the internal components of the sleeve 202 include a first reflector rod 230, a plurality of fuel compacts 232, and a second reflector rod 234. In at least one embodiment, when the fuel sleeve assembly 200 is fully installed inside the reactor, the fuel sleeve assembly 200 is in a compressive configuration. In at least one embodiment, the biasing member 260 is compressed against the structure inside the reactor.

[0056] When the biasing member 260 is compressed, it applies a compressive force to the internal components of the sleeve 202. In at least one embodiment, this compressive force is due to a force applied to the second end cap 240 in the direction toward the first end cap 210 along the longitudinal axis. In some embodiments, the second end cap 240 may move along the longitudinal axis due to this force. The compressive force acting on the internal components of the sleeve 202 eliminates the gap between the internal components. For example, in a compression configuration, the biasing member 260 may be configured to apply a force to the second end cap 240, thereby causing the second end cap 240 to slide along the longitudinal axis until it contacts the second reflector rod 234. The force applied by the biasing member 260 compresses the internal components of the sleeve 202 between the first end cap 210 and the second end cap 240. The greater the force applied to the second end cap 240 in the direction toward the first end cap 210, the greater the compressive force applied to the internal components of the sleeve 202. In some embodiments, the greater the force applied to the second end cap 240 in the direction toward the first end cap 210, the greater the movement of the second end cap 240 toward the first end cap 210. In at least one embodiment, the amount of compressive force that can be applied to the internal components is determined by the length of the slot 254, the parameters of the biasing member 260, and the total length of the internal components located within the sleeve 202.

[0057] In at least one embodiment, during reactor operation, the internal components of the sleeve 202 may elongate axially (e.g., thermally or neutronically induced axial elongation), causing the components to expand along the longitudinal axis 201. Since the second end cap 240 is slidable along the longitudinal axis 201, the internal components of the sleeve 202 can elongate along the longitudinal axis 201 while maintaining the structural integrity of the fuel sleeve assembly 200. In at least one embodiment, the biasing member 260 applies an axial compressive force to the internal components, providing space for the internal components to elongate axially.

[0058] In at least one embodiment, as described above with respect to Figures 8 and 10, the fuel sleeve assembly 200 is first assembled by mechanically connecting the first end cap 210 to the sleeve 202. In this embodiment, the internal components (e.g., reflector rods 230, 234, fuel compact 232, etc.) are then inserted into the sleeve 202 in a desired order. In this embodiment, the second end cap 240 is then mechanically connected to the sleeve, as described above with respect to Figures 9 and 11. In at least one embodiment, the first end cap 210 and the second end cap 240 prevent the internal components from coming out of the sleeve 202 during reactor operation. Furthermore, in at least one embodiment, the sleeve 202 prevents the fuel compact from directly interacting with the reactor core 100.

[0059] An automated process for inserting and removing fuel sleeve assemblies may be developed. A removal tool may be used to insert and remove the fuel sleeve assembly 200 from the reactor. In at least one embodiment, the removal tool is mounted on a robotic arm for the automated process of inserting and removing the fuel sleeve assembly 200. For example, a control circuit may be connected to a camera and a robotic arm. In some embodiments, the camera is configured to provide image data of the reactor core 100 to the control circuit. The control circuit may perform a method for automatically inserting and removing the fuel sleeve assembly 200. An illustrative method of how the automated process may be performed is described below. However, there are multiple possible ways to achieve the automated process, and the method described here is only one example.

[0060] The method includes a control circuit detecting fuel channels in the reactor core 100. In at least one embodiment, the detection of fuel channels is based on image data from a camera. In another embodiment, the detection of fuel channels is based on sensors connected to the control circuit (e.g., proximity sensors, pressure sensors, etc.). Furthermore, the method further includes the control circuit determining whether a fuel sleeve assembly 200 needs to be installed in or removed from the fuel channel. In at least one embodiment, the control circuit compares the location of a fuel channel with a list or map of fuel channels that need to have a fuel sleeve assembly 200 installed or removed. If the fuel sleeve assembly 200 needs to be removed, the method further includes the control circuit controlling a robotic arm to position an extraction tool above the fuel channel. The method further includes the control circuit controlling the robotic arm and the extraction tool to connect the extraction tool to the fuel sleeve assembly. For example, the control circuit may determine that the extraction tool has been connected based on image data and / or data from sensors in the extraction tool. The method further includes, after the removal tool has been connected to the fuel sleeve assembly 200, a control circuit controlling a robotic arm to slide and remove the fuel sleeve assembly 200 from the fuel channel. The method further includes, the control circuit controlling a robotic arm to place the fuel sleeve assembly into a long-term storage container. In some embodiments, the method includes installing a new fuel sleeve assembly 200 after the old fuel sleeve assembly 200 has been removed. If it is necessary to install a fuel sleeve assembly 200, the method further includes, the control circuit controlling a robotic arm to position the removal tool above the new fuel sleeve assembly 200. The method further includes, the control circuit controlling the robotic arm and the removal tool to connect the removal tool to the fuel sleeve assembly 200.The method further includes, after the extraction tool is connected to the fuel sleeve assembly 200, a control circuit controlling a robotic arm to move the fuel sleeve assembly 200 and slide it into the fuel channel. The method further includes, a control circuit controlling the extraction tool to separate the extraction tool from the fuel sleeve assembly 200. This method may be repeated for each detected fuel channel.

[0061] Referring to Figure 11, the end 242 of the second end cap 240 has an extraction tool interface feature 244. In some embodiments, the extraction tool interface feature 244 may be located outside the second end cap 240. For example, the end effector of the extraction tool may be fixed around the extraction tool interface feature 244 for connection with the extraction tool interface feature 244. In another embodiment, the extraction tool interface feature 244 may be an internal cavity. For example, the end effector of the extraction tool may extend into the cavity for connection with the extraction tool interface feature 244. In any case, once the extraction tool is connected to the extraction tool interface feature 244, the extraction tool can move the entire fuel sleeve assembly 200. This process allows the extraction tool to be used to move the fuel sleeve assembly 200 to install or remove it from the fuel channel of the reactor.

[0062] Figure 12 is a perspective view of a sleeve 202 of a fuel sleeve assembly 200 according to at least one embodiment of the present disclosure. In at least one embodiment, the sleeve 202 has a slot 208 extending along the length of the sleeve 202. In this embodiment, the sleeve 202 is subjected to stress during reactor operation, and the slot 208 relieves the stress on the sleeve 202.

[0063] In at least one embodiment, the fuel sleeve assembly 200 is not sealed. For example, the internal components of the fuel sleeve assembly 200 are not affected even if gases from the reactor core 100 enter the fuel sleeve assembly 200. In some other embodiments, the fuel sleeve assembly 200 is configured to be sealed. In this embodiment, an additional biasing member is placed inside the sleeve 202, which is configured to compress the internal components of the sleeve 202 and allow axial extension of the internal components.

[0064] In at least one embodiment, incorporating the reflector rod and biasing member into the fuel sleeve assembly 200 can reduce the complexity and time required for fuel installation in the reactor. For example, without a fuel sleeve assembly, all internal components of the sleeve must be installed individually in the reactor. Having the internal components pre-installed in the fuel sleeve assembly 200 makes fuel installation in the reactor easier and allows for an automated process.

[0065] Figures 13 to 18 show the fuel sleeve assembly 300. Figures 13 to 15 are perspective views, Figures 16 and 17 are side views, and Figure 18 is a cross-sectional view, all showing the fuel sleeve assembly 300 according to at least one aspect of the present disclosure. In Figures 13 to 17, the sleeve 302 is shown as transparent. The fuel sleeve assembly 300 is similar in many respects to the fuel sleeve assembly 200. For example, the sleeve 302, first end 304, second end 306, longitudinal axis 301, fuel compact 332, end 342, take-out tool interface feature 344, and biasing member 360 of the fuel sleeve assembly 300 function in the same way as the sleeve 202, first end 204, second end 206, longitudinal axis 201, fuel compact 332, end 242, take-out tool interface feature 244, and biasing member 260 of the fuel sleeve assembly 200, and are substantially similar. For the sake of brevity, not all similar features and parts will be described in detail. The main difference between fuel sleeve assembly 200 and fuel sleeve assembly 300 is that in fuel sleeve assembly 300, the first end cap is connected to the reflector, and the second end cap is connected to the reflector.

[0066] The fuel sleeve assembly 300 includes a first reflector end 330 and a second reflector end 334, which prevent the fuel compact 332 in the sleeve 302 from coming out of the sleeve 302 while the reactor is operating. The first reflector end 330 is inserted into the first end 304 along the longitudinal axis 301 until the outer portion 310 contacts the first end 304 of the sleeve 302. The outer portion 310 has a retractable portion 316 (Figure 16) similar to the retractable portion 216.

[0067] The first reflector end 330 is mechanically connected to the sleeve 302. In at least one embodiment, the first reflector end 330 is mechanically connected to the sleeve by a retaining pin 314 being inserted into a hole 312 provided in the sleeve 302 and the first reflector end 330, the hole 312 being perpendicular to the longitudinal axis 301. For example, the hole 312 in the first reflector end 330 may be provided such that the hole 312 coincides with the hole 312 in the sleeve 302 when the first reflector end 330 is inserted. Once the retaining pin is positioned in the hole 312, the first reflector end 330 may be held in place relative to the sleeve 302. The first reflector end 330 may be mechanically connected to the sleeve 302 in various ways, one of which is the retaining pin connection. Alternatively, the first reflector end 330 may be screwed onto the first end 304 of the sleeve 302.

[0068] In at least one embodiment, the second reflector end 334 is inserted into the second end 306 of the sleeve 302 along the longitudinal axis 301. The second reflector end 334 is mechanically connected to the sleeve 302 and configured to slide within the sleeve 302 along the longitudinal axis 301. In at least one embodiment, the sleeve 302 has a slot 354 cut into the sleeve 302 along the longitudinal axis 301, and the second reflector end 334 has a hole 350 that penetrates the second reflector end 334 perpendicular to the longitudinal axis 301. A retaining pin 352 can be inserted into the hole 350 and the slot 354. In at least one embodiment, the retaining pin 352 is attached to the second reflector end 334. The second reflector end 334 is slidable within the sleeve 302 over the length of the slot 354. The second reflector end 334 may be mechanically connected to the sleeve 302 in various ways, one of which is a retaining pin-slot connection.

[0069] Figures 19 to 22 show the fuel sleeve assembly 400. Figures 19 and 20 are side views, and Figures 21 and 22 are cross-sectional views, all showing the fuel sleeve assembly 400 according to at least one aspect of the present disclosure. In Figures 19 and 20, the sleeve 402 is shown transparent. The fuel sleeve assembly 400 is similar in many respects to the fuel sleeve assembly 200. For example, the sleeve 402, first end 404, second end 406, longitudinal shaft 401, first end cap 410, retracted section 416, hole 412, retaining pin 414, inner section 418, first reflector 430, fuel compact 432, second reflector 434, second end cap 440, end 442, extraction tool interface feature section 444, and biasing member 460 of the fuel sleeve assembly 400 function in the same way as the sleeve 202, first end 204, second end 206, longitudinal shaft 201, first end cap 210, retracted section 216, hole 212, retaining pin 214, inner section 218, first reflector 230, fuel compact 232, second reflector 234, second end cap 240, end 242, extraction tool interface feature section 244, and biasing member 260 of the fuel sleeve assembly 200, and are substantially the same. For the sake of brevity, not all similar features and parts will be described in detail. The main difference between fuel sleeve assembly 200 and fuel sleeve assembly 400 is that in fuel sleeve assembly 400, slot 454 is located in sleeve 402 rather than in second end cap 440.

[0070] In at least one embodiment, the second end cap 440 is configured to hold the reflector rods 430, 434 and the fuel compact 432. In at least one embodiment, the second end cap 440 is inserted into the second end 406 of the sleeve 402 along the longitudinal axis 401. The second end cap 440 is mechanically connected to the sleeve 402 and configured to slide within the sleeve 402 along the longitudinal axis 401. In at least one embodiment, the sleeve 402 has a slot 454 cut into the sleeve 402 along the longitudinal axis 401, and the second end cap 440 has a hole 450 that penetrates the second end cap 440 perpendicular to the longitudinal axis 401. A retaining pin 452 can be inserted into the hole 450 and the slot 454. In at least one embodiment, the retaining pin 452 is attached to the second end cap 440. The second end cap 440 is slidable within the sleeve 402 over the length of the slot 454. The second end cap 440 may be mechanically connected to the sleeve 402 in various ways, one of which is a retaining pin-slot connection.

[0071] Figures 23 to 26 show the fuel sleeve assembly 500. Figures 23 and 24 are side views, and Figures 25 and 26 are cross-sectional views, each showing the fuel sleeve assembly 500 according to at least one aspect of the present disclosure. In Figures 23 and 24, the sleeve 502 is shown transparent. The fuel sleeve assembly 500 is similar in many respects to the fuel sleeve assembly 200. For example, the sleeve 502, first end 504, second end 506, longitudinal shaft 501, first end cap 510, tapered section 516, hole 512, retaining pin 514, first reflector rod 530, fuel compact 532, second reflector rod 534, second end cap 540, end 542, take-out tool interface feature 544, hole 550, retaining pin 552, slot 554, and biasing member 560 of the fuel sleeve assembly 500 are, respectively, fuel sleeve The first reflector 530 functions similarly to, and is substantially identical to, the sleeve 202, first end 204, second end 206, longitudinal shaft 201, first end cap 210, retractable section 216, hole 212, retaining pin 214, first reflector 230, fuel compact 232, second reflector 234, second end cap 240, end 242, take-out tool interface feature section 244, hole 250, retaining pin 252, slot 254, and biasing member 260 of the fuel sleeve assembly 200. For the sake of brevity, not all similar features and parts will be described in detail. The main difference between the fuel sleeve assembly 200 and the fuel sleeve assembly 500 is that in the fuel sleeve assembly 500, the first reflector 530 is moved to the outside of the fuel sleeve assembly 500.

[0072] In at least one embodiment, the first reflector rod 530 is inserted into the reactor fuel channel before the fuel sleeve assembly 500 is inserted. The first reflector rod 530 has a tapering portion 531 that reduces the end of the first reflector rod 530 that is inserted into the reactor. The first end cap 510 is configured to hold the second reflector rod 534 and the fuel compact 532 within the sleeve 502. In at least one embodiment, the inner portion 518 of the first end cap 510 is inserted into the first end portion 504 of the sleeve 502 along the longitudinal axis 501. The inner portion 518 is in contact with one of the fuel compacts 532. The first end cap 510 is mechanically connected to the sleeve 502 in the same way that the first end cap 210 is mechanically connected to the sleeve 202.

[0073] Figures 27 and 28 show the external extraction tool interface feature 668. Figure 27 is a perspective view of a fuel sleeve assembly 600 according to at least one aspect of the present disclosure, and Figure 28 is a cross-sectional view thereof. The fuel sleeve assembly 600 is substantially similar to the fuel sleeve assembly 200. For the sake of brevity, not all similarities will be described in detail. The main difference between the fuel sleeve assembly 600 and the fuel sleeve assembly 200 is that in the fuel sleeve assembly 600, the second end cap 640 includes the external extraction tool interface feature 668.

[0074] The fuel sleeve assembly 600 includes a second end cap 640 and a first end cap (not shown) which prevent internal components within the sleeve 602 from coming out of the sleeve 602 during reactor operation. In at least one embodiment, the sleeve 602 houses and holds a second reflector rod 634, a first reflector rod, and a plurality of fuel compacts. A biasing member 660 (e.g., a plenum spring) is inserted into the second end 606 of the sleeve 602 along its longitudinal axis 601 and is in contact with the second reflector rod 634. The second end cap 640 has an outer portion 641 that remains outside the sleeve 602 and an inner portion 643 that is inserted into the second end 606 of the sleeve 602 along its longitudinal axis 601. When the inner portion 643 is inserted, it compresses the biasing member 660, putting the fuel sleeve assembly 600 into a compressed configuration. For example, the force applied by the biasing member 660 compresses the internal components of the sleeve 602 between the first end cap and the second end cap 640. In at least one embodiment, the biasing member 660 allows the internal components of the sleeve 602 to axially elongate (e.g., thermally and neutronically induced axial elongation) and expand along the longitudinal axis 601, while maintaining the structural integrity of the fuel sleeve assembly 600.

[0075] The second end cap 640 is mechanically connected to the sleeve 602 and configured to slide within the sleeve 602 along the longitudinal axis 601. In at least one embodiment, the sleeve 602 has a slot 654 cut into the sleeve 602 along the longitudinal axis 601, and the second end cap 640 has a hole 650 that penetrates the second end cap 640 perpendicular to the longitudinal axis 601. A retaining pin 652 can be inserted into the hole 650 and the slot 654. In at least one embodiment, the retaining pin 652 is attached to the second end cap 640. The second end cap 640 is slidable within the sleeve 602 over the length of the slot 654. The second end cap 640 may be mechanically connected to the sleeve 602 in a variety of ways, the retaining pin-slot connection being one such way.

[0076] Referring to Figure 28, the second end cap 640 has an external extraction tool interface feature 668 extending away from the outer portion 641 of the second end cap 640. The external extraction tool interface feature 668 has a shaft 666 extending away from the outer portion 641 along its longitudinal axis and a button head 662. In at least one embodiment, the button head 662 is rounded on the side far from the outer portion 641 and has a flat opposing edge 664 on the side facing the outer portion 641. In at least one embodiment, the extraction tool slides over and around the button head 662 to engage the flat opposing edge 664 and connect to the fuel sleeve assembly 600, thereby allowing the extraction tool to move the entire fuel sleeve assembly 600. This process allows the extraction tool to insert the fuel sleeve assembly 600 into or remove the fuel sleeve assembly 600 from the reactor.

[0077] The external extraction tool interface feature 668 is an example of an external extraction tool interface feature. Another example is a donut shape attached to the end of a second end cap on the outside of the sleeve, with the hole in this donut shape perpendicular to the longitudinal axis 601. This allows an extraction tool to connect to the second end cap inside the hole. Other examples are also conceivable, attached to the end of the second end cap and used for connection to the fuel sleeve assembly.

[0078] Figures 29 and 30 show the external extraction tool interface feature 768. Figure 29 is a perspective view of a fuel sleeve assembly 700 according to at least one aspect of the present disclosure, and Figure 30 is a cross-sectional view thereof. The fuel sleeve assembly 700 is substantially similar to the fuel sleeve assembly 600. For example, the sleeve 702, second end 706, longitudinal shaft 701, second reflector rod 734, second end cap 740, biasing member 760, button head 762, flat opposing edge 764, shaft 766, and external extraction tool interface feature 768 of the fuel sleeve assembly 700 function in the same way as the sleeve 602, second end 606, longitudinal shaft 601, second reflector rod 634, second end cap 640, biasing member 660, button head 662, flat opposing edge 664, shaft 666, and external extraction tool interface feature 668 of the fuel sleeve assembly 600, and are substantially similar. For the sake of brevity, not all similar features and parts will be described in detail. The main difference between fuel sleeve assembly 700 and fuel sleeve assembly 600 is that in fuel sleeve assembly 700, the second end cap 740 has a slot 754 formed inward from the second end cap 740.

[0079] The sleeve 702 houses and holds the second reflector rod 734, the first reflector rod, and a plurality of fuel compacts 732. A biasing member 760 (e.g., a plenum spring) is inserted into the second end 706 of the sleeve 702 along the longitudinal axis 701 and is in contact with the second reflector rod 734. In at least one embodiment, the second reflector rod 734 has a projection 735 that extends toward the second end 706 of the sleeve 702 through the biasing member 760 in a direction away from the second reflector rod 734.

[0080] The second end cap 740 is configured to be mechanically connected to the sleeve 702. In at least one embodiment, the sleeve 702 has one or more holes 750 that penetrate the sleeve 702 perpendicular to the longitudinal axis 701. In at least one embodiment, the second end cap 740 has four internal legs 770, with slots 754 formed between them. Each internal leg 770 terminates with a projection 772 extending radially outward from the internal leg 770. The projection 772 has a tapering portion 774 that reduces the end of the internal leg 770 that is farther from the second end cap 740. In at least one embodiment, the tapering portion 774 of the internal leg 770 allows the internal leg 770 to easily enter the second end 706 of the sleeve 702 along the longitudinal axis 701. For example, the internal legs 770 are compressed toward each other as they enter the sleeve 702, and the second end cap 740 is moved along the longitudinal axis 701 until the projection 772 engages with the hole 750. In at least one embodiment, the second end cap 740 is properly inserted when the projection 772 engages with the hole 750 of the sleeve 702. The second end cap 740 may have any number of internal legs 770, each internal leg 770 having a projection corresponding to the hole 750 of the sleeve 702.

[0081] When the second end cap 740 is properly inserted, the internal leg 770 compresses the biasing member 760, causing the fuel sleeve assembly 700 to enter a compressed configuration. For example, the force applied by the biasing member 760 compresses the internal components of the sleeve 702 between the first end cap (not shown) and the second end cap 740. In at least one embodiment, the biasing member 760 allows the internal components of the sleeve 702 to expand axially (for example, thermally or neutronically induced axial expansion) while maintaining the structural integrity of the fuel sleeve assembly 700, causing the components to expand along the longitudinal axis 701. In at least one embodiment, when the second end cap 740 is properly inserted, the projection 735 of the second reflector rod 734 extends through the biasing member 760 into a slot 754 formed in the second end cap 740.

[0082] (example) Various aspects of the subject matter described herein are shown in the following numbered examples.

[0083] Example 1 - A reactor fuel rod used in a nuclear reactor. The reactor fuel rod comprises a sleeve that defines its longitudinal axis. The sleeve has a first end and a second end. The reactor fuel rod further comprises a first end cap mechanically connected to the first end of the sleeve and a second end cap mechanically connected to the second end of the sleeve. The second end cap is configured to slide along the longitudinal axis relative to the sleeve. The reactor fuel rod further comprises a fuel compact positioned between the first end cap and the second end cap within the sleeve.

[0084] Example 2 - A reactor fuel rod of Example 1, further comprising a reflector positioned between the fuel compact and the second end cap within the sleeve.

[0085] Example 3 - A reactor fuel rod of Example 2, wherein the reflector is a first reflector, and the reactor fuel rod further comprises a second reflector positioned between the fuel compact and the first end cap within the sleeve.

[0086] Example 4 - A reactor fuel rod of Example 1, 2, or 3, wherein the second end cap comprises an end cap end and a biasing member attached to the end cap end.

[0087] Example 5 - A reactor fuel rod of Example 4, wherein the reactor fuel rod is transitionable from an uncompressible state to a compressed state, and is in a compressed state within the reactor, and in the compressed state, the biasing member is configured to apply force to the second end cap to compress the fuel compact.

[0088] Example 6 - A reactor fuel rod of Example 1, 2, 3, 4, or 5, wherein the sleeve has a slot located at the second end, and the second end cap has a retaining pin configured to slide within the slot.

[0089] Example 7 - A reactor fuel rod of Example 1, 2, 3, 4, 5, or 6, wherein the second end cap comprises a slot and a retaining pin inserted into the slot, the retaining pin being attached to the sleeve at the second end, and the second end cap is configured to slide relative to the sleeve.

[0090] Example 8 - A reactor fuel rod of Example 1, 2, 3, 4, 5, 6, or 7, wherein the sleeve has a slot extending along the longitudinal axis of the sleeve from the first end to the second end.

[0091] Example 9 - A reactor fuel rod of Example 1, 2, 3, 4, 5, 6, 7, or 8, wherein the second end cap is equipped with a removal tool interface feature.

[0092] Example 10 - The extraction tool mechanically connects to the extraction tool interface feature to insert the fuel rod into the reactor, extracting the fuel rod from the reactor, as in Example 9.

[0093] Example 11 - Reactor fuel rod of Example 9 or 10, in which the extraction tool interface feature is formed by an internal cavity in the second end cap.

[0094] Example 12 - The extraction tool interface feature extends outward from the second end cap of a reactor fuel rod of Example 9, 10, or 11.

[0095] Example 13 - A sleeve prevents direct interaction between the fuel compact and the reactor fuel rods of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

[0096] Example 14 - Reactor fuel rod used in a nuclear reactor. The reactor fuel rod comprises a tube defining a longitudinal axis. The tube has a first end and a second end. The reactor fuel rod further comprises a first end cap mechanically connected to the first end of the tube and a second end cap having an extraction tool interface feature. The second end cap is mechanically connected to the second end of the tube. The second end cap is configured to move along the longitudinal axis relative to the tube. The reactor fuel rod further comprises a plurality of fuel pellets positioned between the first end cap and the second end cap within the tube.

[0097] Example 15 - The reactor fuel rod of Example 14, further comprising a biasing member configured to compress a plurality of fuel pellets.

[0098] Example 16 - The reactor fuel rod of Example 14, further comprising a reflector positioned between a plurality of fuel pellets and a second end cap within the tube.

[0099] Example 17 - A reactor fuel rod of Example 16, wherein the reflector is a first reflector, and the reactor fuel rod further comprises a second reflector positioned between a plurality of fuel pellets and a first end cap within the tube.

[0100] Example 18 - A reactor fuel rod of Example 14, wherein the tube has a slot extending along the longitudinal axis of the tube from the first end to the second end.

[0101] Example 19 - Method for inserting nuclear fuel into a reactor using reactor fuel rods. The method includes connecting a first end cap of the reactor fuel rod to a first end of the sleeve of the reactor fuel rod, inserting a fuel pellet into the sleeve, and connecting a second end cap of the reactor fuel rod to a second end of the sleeve so that the fuel pellet is positioned between the first and second end caps. The method further includes connecting an extraction tool to an extraction tool interface feature of the reactor fuel rod, and using the extraction tool to position the reactor fuel rod in the reactor.

[0102] Example 20 - The method of Example 19, further comprising moving a second end cap relative to the sleeve to compress the fuel pellet.

[0103] All patents, patent applications, published documents, or other disclosure materials referenced herein are cited by reference in whole, as if each were expressly cited as an individual reference. All references and any materials, or any part thereof, cited by reference herein are cited herein to the extent that the cited material does not conflict with any definitions, statements, or other disclosure materials set forth herein. Accordingly, where necessary, disclosures expressly set forth herein take precedence over any conflicting material cited herein, and the disclosures expressly set forth in this application shall prevail.

[0104] The embodiments described herein are understood to provide exemplary features of different details of various embodiments of this disclosure. Therefore, unless otherwise specified, it should be understood that, to the extent possible, one or more features, elements, components, constituents, components, structures, modules, and / or embodiments of the disclosed embodiments may be combined with, divided, replaced, and / or rearranged with one or more other features, elements, components, constituents, components, structures, modules, and / or embodiments of the disclosed embodiments without departing from the scope of the invention. Accordingly, those skilled in the art will recognize that any of the exemplary embodiments may be replaced, modified, or combined in various ways without departing from the scope of the invention. Furthermore, those skilled in the art will be able to recognize and readily identify many equivalents of the various embodiments described herein by ordinary experimentation upon reading this specification. Therefore, this disclosure is limited by the claims, not by the descriptions of the various embodiments.

[0105] Those skilled in the art will generally recognize that the terms used in this specification, and especially in the appended claims (e.g., the main body of the appended claims), are "open" terms (for example, the word "includes" should be interpreted as "includes, but not limited to," the word "have" should be interpreted as "have at least," and the word "includes" should be interpreted as "includes, but not limited to," etc.). Those skilled in the art will also recognize that if there is an intention to describe a particular number of elements in a claim, such intention is explicitly stated in the claim; if there is no such statement, then no such intention exists. For example, to aid understanding, the appended claims sometimes introduce elements using the introductory phrases "at least one" and "one or more." However, the use of such phrases should not be interpreted as limiting a particular claim containing an element introduced by the indefinite article "a" or "an" to a claim containing only one such element, even if the same claim contains "one or more" or "at least one" and an indefinite article such as "a" or "an" (for example, "a" and / or "an" should normally be interpreted as meaning "at least one" or "one or more"). The same applies to definite articles used to introduce elements into claims.

[0106] In addition, even if the number of elements in a claim is explicitly stated, a person skilled in the art would recognize that such elements are usually interpreted to mean at least the number stated (for example, the statement “two elements” without other modifying phrases usually means at least two elements, or two or more elements). Furthermore, when expressions similar to “at least one of A, B, and C, etc.” are used, such expressions are generally intended to be understood by a person skilled in the art (for example, “a system having at least one of A, B, and C” includes, but is not limited to, a system having only A, a system having only B, a system having only C, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.). When expressions similar to "at least one of A, B, or C" are used, such expressions are generally intended to be understood by those skilled in the art (for example, "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, a system having only B, a system having only C, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C). As those skilled in the art will further understand, in any specification, claims, or drawings, disjunct words and / or disjunct phrases presenting two or more alternative words should generally be understood, unless otherwise specified in the context, as contingent on the possibility of including one of the words, either of the words, or both of the words. For example, the expression "A or B" is generally understood to include the possibility of being "A", or "B", or "A and B".

[0107] Those skilled in the art will understand that, with respect to the attached claims, the operations described herein may generally be performed in any order. Furthermore, while various operation flowcharts are shown sequentially, it should be understood that various operations may be performed in orders other than those illustrated, or simultaneously. Examples of such alternative orders include overlapping, interleaved, interrupted, reordered, incremental, and preparation orders. Moreover, past tense adjectives such as "corresponding to" and "related to" are generally not intended to exclude such variations unless otherwise specified in the context.

[0108] It should be noted that references to "one aspect," "a certain aspect," "an example," or "an example" mean that the specific features, structures, or characteristics described in relation to that aspect are included in at least one aspect. Therefore, while expressions such as "in one aspect," "a certain aspect," "in an example," and "in an example" appear in various parts of this specification, they do not necessarily all refer to the same aspect. Furthermore, specific features, structures, or characteristics can be combined in any suitable way in one or more aspects.

[0109] In this specification, the singular forms "a," "an," and "the" include the plural forms unless otherwise specified.

[0110] The directional expressions used herein (including, but not limited to, up, down, left, right, downward, upward, front, back, and variations thereof) relate to the orientation of elements shown in the accompanying drawings and do not limit the claims unless expressly otherwise noted.

[0111] In any aspect of this specification, the term “control circuit” means, for example, hardwired circuits, programmable circuits (e.g., computer processors, processing units, processors, microcontrollers, microcontroller units, controllers, digital signal processors (DSPs), programmable logic devices (PLDs), programmable logic arrays (PLAs), or field-programmable gate arrays (FPGAs) including one or more individual instruction processing cores), state machine circuits, firmware storing instructions executed by programmable circuits, and any combination thereof. Control circuits are implemented, alone or in combination, as circuits that constitute part of a larger system, such as an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system-on-a-chip (SoC), a desktop computer, a laptop computer, a tablet computer, a server, or a smartphone. Accordingly, in this specification, “control circuit” includes, but is not limited to, an electrical circuit having at least one discrete electrical circuit, an electrical circuit having at least one integrated circuit, an electrical circuit having at least one application-specific integrated circuit, an electrical circuit forming a general-purpose computer device configured by a computer program (e.g., a general-purpose computer configured by a computer program that performs at least a portion of the processes and / or devices described herein, or a microprocessor configured by a computer program that performs at least a portion of the processes and / or devices described herein), an electrical circuit forming a memory device (e.g., in the form of random access memory), and / or an electrical communication device (e.g., a modem, a communication switch, or an optoelectronic device). Those skilled in the art will understand that the subject matter described herein can be implemented in analog, digital, or combination thereof.

[0112] As used in this disclosure, the terms “about” or “approximately” mean, unless otherwise specified, an acceptable error to a particular value as determined by a person skilled in the art, which depends in part on how the value is measured or determined. In certain embodiments, the terms “about” or “approximately” mean within 1, 2, 3, or 4 standard deviations. In certain embodiments, the terms “about” or “approximately” mean within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range.

[0113] In this specification, unless otherwise specified, all numerical parameters should be understood to be preceded and modified in all cases by the word “approximately.” In this case, the numerical parameters have inherent variability characteristic of the underlying measurement technique used to determine the numerical value of the parameter. Not to the effect of limiting the application of the doctrine of equivalents to the claims, each of the numerical parameters described herein should be interpreted using ordinary rounding techniques, taking into account at least the number of significant figures reported.

[0114] Numerical ranges described herein include all subranges encompassed within the described range. For example, the range "1 to 100" includes all subranges (and including them) between the stated minimum value "1" and the stated maximum value "100," i.e., all subranges where the minimum value is 1 or greater and the maximum value is 100 or less. Furthermore, all ranges described herein include their endpoints. For example, the range "1 to 100" includes endpoints 1 and 100. The maximum numerical limit described herein is intended to include all subranges encompassed therewith, and the minimum numerical limit described herein is intended to include all upper numerical limits encompassed therewith. Accordingly, the applicant has the right to amend this specification, including the claims, to explicitly describe any subranges encompassed within an explicitly described range. All such ranges are essentially described herein.

[0115] Any patent applications, patents, non-patent publications, or other disclosure materials mentioned herein and / or included in application data sheets are incorporated herein by reference, to the extent that the incorporated material does not conflict with this Specified. To this extent, the disclosures expressly contained herein take precedence over any conflicting material incorporated herein by reference. Any material or any part thereof that is to be incorporated by reference that conflicts with existing definitions, descriptions, or other disclosure materials contained herein is incorporated only to the extent that it does not create a conflict between the incorporated material and the existing disclosure materials.

[0116] "To have" (and any form of "to have," such as "has" or "is having"), "to possess" (and any form of "to possess," such as "has" or "is having"), "to include" (and any form of "to include," such as "has" or "is including"), and "to contain" (and any form of "to contain," such as "has contained" or "is containing") are open-ended linking verbs. Therefore, a system that "has," "possesses," "possesses," or "contains" one or more elements has one or more of those elements, but is not limited to having only one or more of those elements. Similarly, an element of a system, device, or apparatus that "has," "possesses," "possesses," or "contains" one or more features has one or more of those features, but is not limited to having only one or more of those features.

Claims

1. A reactor fuel rod used in a nuclear reactor, The aforementioned reactor fuel rods are A sleeve that defines the longitudinal axis and has a first end and a second end, A first end cap mechanically connected to the first end of the sleeve, A second end cap is mechanically connected to the second end of the sleeve and configured to slide along the longitudinal axis relative to the sleeve, The sleeve comprises a fuel compact positioned between the first end cap and the second end cap inside the sleeve, nuclear reactor fuel rods.

2. The sleeve further comprises a reflector positioned between the fuel compact and the second end cap inside the sleeve. A reactor fuel rod according to claim 1.

3. The aforementioned reflective material is a first reflective material, The reactor fuel rod further comprises a second reflector positioned inside the sleeve between the fuel compact and the first end cap. A reactor fuel rod according to claim 2.

4. The second end cap comprises an end cap end and a biasing member attached to the end cap end. A reactor fuel rod according to claim 1.

5. The reactor fuel rod is capable of transitioning from an uncompressible state to a compressed state. The reactor fuel rod is in the compressed state within the reactor. In the compressed state, the biasing member is configured to apply force to the second end cap to compress the fuel compact. A reactor fuel rod according to claim 4.

6. The sleeve is provided with a slot located at the second end, The second end cap includes a retaining pin configured to slide within the slot. A reactor fuel rod according to claim 1.

7. The second end cap comprises a slot and a retaining pin inserted into the slot, The retaining pin is attached to the sleeve at the second end, The second end cap is configured to slide against the sleeve. A reactor fuel rod according to claim 1.

8. The sleeve has a slot that extends along the longitudinal axis of the sleeve from the first end to the second end. A reactor fuel rod according to claim 1.

9. The second end cap is equipped with a feature portion for the extraction tool interface. A reactor fuel rod according to claim 1.

10. The extraction tool is mechanically connected to the extraction tool interface feature to insert the fuel rod into the reactor or to extract the fuel rod from the reactor. A reactor fuel rod according to claim 9.

11. The aforementioned extraction tool interface feature is formed by the internal cavity of the second end cap. A reactor fuel rod according to claim 9.

12. The aforementioned extraction tool interface feature extends outward from the second end cap. A reactor fuel rod according to claim 9.

13. The sleeve prevents direct interaction between the fuel compact and the reactor. A reactor fuel rod according to claim 1.

14. A reactor fuel rod used in a nuclear reactor, The aforementioned reactor fuel rods are A tube having a defined longitudinal axis and a first end and a second end, A first end cap mechanically connected to the first end of the pipe, A second end cap is provided, which has a extraction tool interface feature, is mechanically connected to the second end of the tube, and is configured to move along the longitudinal axis of the tube, The pipe comprises a plurality of fuel pellets arranged between the first end cap and the second end cap inside the pipe, nuclear reactor fuel rods.

15. The reactor fuel rod further comprises a biasing member configured to compress the plurality of fuel pellets. A reactor fuel rod according to claim 14.

16. The tube further comprises a reflector positioned between the plurality of fuel pellets and the second end cap inside the tube. A reactor fuel rod according to claim 14.

17. The aforementioned reflective material is a first reflective material, The reactor fuel rod further comprises a second reflector positioned inside the tube between the plurality of fuel pellets and the first end cap. A reactor fuel rod according to claim 16.

18. The pipe has a slot that extends along the longitudinal axis of the pipe from the first end to the second end. A reactor fuel rod according to claim 14.

19. A method for inserting nuclear fuel into a nuclear reactor using reactor fuel rods, The aforementioned method, The first end cap of the reactor fuel rod is connected to the first end of the sleeve of the reactor fuel rod, Inserting fuel pellets into the sleeve, The second end cap of the reactor fuel rod is connected to the second end of the sleeve so that the fuel pellet is positioned between the first end cap and the second end cap inside the sleeve. Connecting the extraction tool to the aforementioned reactor fuel rod extraction tool interface feature section, The method includes using the aforementioned removal tool to position the reactor fuel rods inside the reactor. method.

20. The method further comprises moving the second end cap relative to the sleeve to compress the fuel pellet. The method according to claim 19.

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