Lattice sleeve and shield plug handling tool

Abstract

According to an aspect, there is provided a lattice sleeve and shield plug assembly. The assembly includes a shield plug comprising a flange and a plug and a lattice sleeve. The lattice sleeve includes a sleeve to engage a fuel channel after removal of an end fitting, a face with an opening configured to receive the shield plug through the face and into the fuel channel, and a stud configured to insert through a stop tube through to an end shield. According to an aspect, there is provided a shield plug including a flange, a plug, and one or more barbs configured to engage the interior of a lattice site. According to an aspect, there is provided a tool to handle a payload. The tool including an arm equipped with a gripping member.

Description

LATTICE SLEEVE AND SHIELD PLUG HANDLING TOOLCROSS-REFERENCE

[0001] This application claims priority from United Stated patent application 63 / 597,029, titled “LATTICE SLEEVE AND SHIELD PLUG HANDLING TOOL”, filed on November 8, 2023, the contents of which are incorporated herein by reference.FIELD

[0002] Embodiments of the present disclosure generally relate to the field of nuclear energy, and more specifically to devices, systems, and methods for improved lattice sleeves and shield plug assemblies.INTRODUCTION

[0003] During, for example, retube and / or decommissioning operations various components of the fuel channel may be removed. For example, after the removal of an end fitting, the opening may still be transmitting radiation onto the fueling machine side tube sheet. The opening may further increase the amount of radioactive material that needs to be managed and removed from the reactor vault or decrease the amount of time that workers can safely work within the reactor vault.

[0004] Improvement in the realm of radioactivity closure and control are desirable.SUMMARY

[0005] During, for example, retube and / or decommissioning operations various components of the fuel channel may be removed in, for example, a step-wise fashion. For example, after the removal of an end fitting, it may be desirable to install a lattice sleeve and shield plug assembly to prevent the release of radiation and radioactivity. This may reduce the amount of radioactivity within the vault. It may also reduce the amount of radiation to which the fueling machine side tube sheet and workers may be exposed. Described herein are lattice sleeve and shield plug assemblies and tools for installing and handling same. Features of the lattice sleeve and shield plug assemblies may also make their installation more straightforward.

[0006] Beyond these advantages, lattice sleeves and shield plug assemblies can allow the tools to interface with the reactor components to aid the removal of the components. For example, they may be used as a guide for tooling to be inserted into the lattice site to perform further removal operations of the pressure tube, calandria tube insert, and calandria tube.

[0007] According to an aspect, there is provided a lattice sleeve and shield plug assembly. The assembly includes a shield plug comprising a flange and a plug and a lattice sleeve. The lattice sleeve includes a sleeve to engage a fuel channel after removal of an end fitting, a face with an opening configured to receive the shield plug through the face and into the fuel channel, and a stud configured to insert through a stop tube through to an end shield.

[0008] In some embodiments, the lattice sleeve further comprises at least one of a threaded stud and a stop tube.

[0009] In some embodiments, the opening is symmetric relative to the face.

[0010] In some embodiments, the opening is asymmetric relative to the face.

[0011] In some embodiments, the lattice sleeve further includes a tab configured to secure the lattice sleeve to a neighbouring lattice sleeve.

[0012] In some embodiments, the lattice sleeve further includes a contamination plate.

[0013] In some embodiments, the lattice sleeve further includes a shipping tab to secure the shield plug during transportation.

[0014] In some embodiments, the lattice sleeve further includes at least one alignment indicia or marking.

[0015] In some embodiments, the at least one alignment indicia or marking includes at least one fiducial markings.

[0016] In some embodiments, the lattice sleeve further includes an identification number.

[0017] In some embodiments, at least one of the shield plug and a front face of the sleeve includes a radiation attenuating material.

[0018] In some embodiments, the radiation attenuating material includes steel.

[0019] In some embodiments, the radiation attenuating material includes tungsten.

[0020] In some embodiments, at least one of the shield plug and a front face of the sleeve includes a thickness of 2 or more inches.

[0021] According to an aspect, there is provided a shield plug including a flange, a plug, and one or more barbs configured to engage the interior of a lattice site.

[0022] In some embodiments, the shield plug includes a radiation attenuating material.

[0023] In some embodiments, the radiation attenuating material includes steel.

[0024] In some embodiments, the radiation attenuating material includes tungsten.

[0025] In some embodiments, the shield plug has a thickness of 2 or more inches.

[0026] According to an aspect, there is provided a tool to handle a shield plug. The tool including a carriage comprising an arm equipped with a gripping member.

[0027] In some embodiments, the tool is configured to remove a shield plug from a lattice sleeve using the gripping member and insert the shield plug into the lattice sleeve using the gripping member.

[0028] In some embodiments, the tool further includes a second carriage including a second arm equipped with a second gripping member. The tool is configured to insert or remove a payload from a lattice site when the shield plug is removed.

[0029] In some embodiments, the tool is configured to insert a payload into a lattice site after the shield plug removal.

[0030] In some embodiments, the tool is further configured to align with a lattice sleeve using an alignment indicia or marking on the lattice sleeve.

[0031] In some embodiments, the tool is configured to install at least one of the lattice sleeve and shield plug assembly described above at a lattice site, the shield plug described above in the lattice sleeve described above, and the shield plug described above at the lattice site.

[0032] In some embodiments, the carriage is a first carriage, and the tool includes a second carriage and a controller. The controller is configured to couple a first payload to the grippingmember of the first carriage, move the first carriage to toward a lattice site of nuclear reactor to insert the first payload into a lattice tube, retract the gripping member of the first carriage from the lattice tube, move the second carriage to align a second payload coupled to a gripping member of the second carriage with the lattice tube, and move the second carriage toward the lattice site to insert the second payload into the lattice tube.

[0033] In some embodiments, the controller is configured to release a first payload in the lattice tube.

[0034] According to an aspect, there is provided a tool to handle a payload. The tool includes a first arm equipped with a first gripping member configured to couple to an exterior of a first payload, a second arm equipped with a second gripping member configured to couple to an exterior of a second payload, and an actuator to selectively extend the first arm and second arm towards a face of a nuclear reactor.

[0035] In some embodiments, the tool is configured to remove a shield plug from a lattice sleeve using the first gripping member by coupling to an exterior of the shield plug and retracting the shield plug and insert the shield plug into the lattice sleeve using the first gripping member by inserting the shield plug and decoupling from the exterior of the shield plug.

[0036] In some embodiments, the tool is configured to insert the first or second payload into a lattice site after the shield plug removal using the second gripping member by inserting the payload.

[0037] In some embodiments, the tool is further configured to align with a lattice sleeve using an alignment indicia or marking on a face of a thumbtack detected with a camera.

[0038] In some embodiments, the tool includes a controller configured to couple a first payload to the first gripping member, move the first arm to toward a lattice site of a nuclear reactor to insert the first payload into a lattice tube, retract the first gripping member from the lattice tube, move the second arm to align the second payload coupled to the second gripping member with the lattice tube, move the second arm toward the lattice site to insert the second payload into the lattice tube.

[0039] In some embodiments, the controller is configured to: couple the first or second gripping member to the lattice sleeve and shield plug assembly of according to this disclosure and move the lattice sleeve and shield plug assembly into a lattice site; or couple the first orsecond gripping member to the shield plug according to this disclosure and move the shield plug into the lattice site. In some embodiments, the controller is configured to release the first payload in the lattice tube.

[0040] Some embodiments further include a controller configured to sent data to the first and second gripping member to insert the first or second payload.

[0041] In some embodiments, the controller is configured to optically scan fiducial markings on a thumbtack to identify a centroid position of a channel defined by a lattice sleeve of the thumbtack; move one of the first or second gripping member coupled to a payload to align the payload with the centroid position for insertion of the payload into the channel; move the one of the first or second gripping member to position the payload into the channel. According to an aspect, there is provided a tool to handle a payload. The tool includes an arm comprising a gripping member configured to couple to a payload, optionally an exterior of the payload, an actuator to extend the arm towards a face of a nuclear reactor or withdraw the arm away from the face of the nuclear reactor, a first lifter configured to receive a first payload from the gripping member or deliver the first payload to a gripping member, and a second lifter configured to receive a second payload from the gripping member or deliver the second payload to a gripping member. The first and second lifters are each configured to move between a first position in a path of the arm equipped with the gripping member and a second position out of the path of the arm equipped with the gripping member.

[0042] In an embodiment, the tool comprises a controller configured to: move the first lifter to position the first payload into axial alignment with the arm, the first lifter coupled to the first payload; couple the gripping member to the first payload; extend the arm toward the face of the nuclear reactor to position the first payload in a lattice tube; withdraw the arm from the face of the nuclear reactor to position the first payload on the first lifter; move the first lifter and the first payload out of axial alignment with the arm; move the second lifter to position the second payload into axial alignment with the arm, the second lifter coupled to the second payload; couple the gripping member to the second payload; and extend the arm toward.

[0043] Many further features and combinations thereof concerning embodiments described herein will appear to those skilled in the art following a reading of the instant disclosure.DESCRIPTION OF THE FIGURES

[0044] Reference is now made to the accompanying drawings, in which:

[0045] FIG. 1 is a perspective of a reactor core of a CANDUTM-type reactor.

[0046] FIG. 2 is a cutaway view of one fuel channel assembly of the reactor core illustrated in FIG. 1.

[0047] FIG. 3 illustrates a flow chart of a removal process for retubing a nuclear reactor according to some embodiments.

[0048] FIG. 4A illustrates a perspective view of a shield plug, according to some embodiments.

[0049] FIG. 4B illustrates a perspective view of a Thumbtack with the shield plug inserted therein, according to some embodiments.

[0050] FIG. 4C shows an alternative face of the Thumbtack, according to some embodiments.

[0051] FIG. 5A illustrates a perspective view of a reactor face with Thumbtacks installed, according to some embodiments.

[0052] FIG. 5B illustrates a plan view of the thumbtack shown in FIG. 5A, according to some embodiments.

[0053] FIG. 6A illustrates a perspective view of a lattice sleeve handling tool, according to some embodiments.

[0054] FIG. 6B illustrates a perspective view of the lattice sleeve handling tool of FIG. 6A without the casing, according to some embodiments.

[0055] FIGs. 7A and 7B each illustrate a perspective view of an alternative Thumbtack configuration, according to some embodiments.

[0056] FIG. 8 is a schematic diagram of computing device, according to some embodiments.DETAILED DESCRIPTION

[0057] Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways.

[0058] General Reactor Design Details.

[0059] FIG. 1 is a perspective of a reactor core of a CANDUTM-type reactor 6. The reactor core is typically contained within a vault that is sealed with an air lock for radiation control and shielding. Although aspects are described with particular reference to the CANDUTM-type reactor 6 for convenience, the disclosure is not limited to CANDU™-type reactors, and may be useful outside this particular field as well. A generally cylindrical vessel, known as the calandria vessel 10 of the CANDUTM-type reactor 6, contains a heavy-water moderator. The calandria vessel 10 has an annular shell 14 and a tube sheet 18 at a first end 22 and a second end 24. The tube sheets 18 include a plurality of apertures (referred to herein as bores 19) that each accept a fuel channel assembly 28. As shown in FIG. 1 , a number of fuel channel assemblies 28 pass through the tube sheets 18 of calandria vessel 10 from the first end 22 to the second end 24.

[0060] As in the illustrated embodiment of FIG. 1 and FIG. 2, in some embodiments the reactor core is provided with two walls at each end 22, 24 of the reactor core: an inner wall defined by the tube sheet 18 at each end 22, 24 of the reactor core, and an outer wall 64 (often referred to as a “end shield”) located a distance outboard from the tube sheet 18 at each end 22, 24 of the reactor core. A lattice tube 65 spans the distance between the tube sheet 18 and the end shield 64 at each pair of bores 19 (i.e., in the tube sheet 18 and the end shield 64, respectively).

[0061] FIG. 2 is a cutaway view of one fuel channel assembly 28 of the reactor core illustrated in FIG. 1. As illustrated in FIG. 2, each fuel channel assembly 28 includes a calandria tube (“CT”) 32 surrounding other components of the fuel channel assembly 28. The CTs 32 each span the distance between the tube sheets 18. Also, the opposite ends of each CT 32 are received within and sealed to respective bores 19 in the tube sheets 18. In some embodiments, a rolled joint insert, for example calandria tube insert 34, is used to secure the CT 32 to the tube sheet 18 within the bores 19. A pressure tube (“PT”) 36 forms an inner wall of the fuel channel assembly 28. The PT 36 provides a conduit for reactor coolant and fuel bundles or assemblies 40. The PT36, for example, generally holds two or more fuel assemblies 40, and acts as a conduit for reactor coolant that passes through each fuel assembly 40. An annulus space 44 is defined by a gap between each PT 36 and its corresponding CT 32. The annulus space 44 is normally filled with a circulating gas, such as dry carbon dioxide, helium, nitrogen, air, or mixtures thereof. One or more annulus spacers or garter springs 48 are disposed between the CT 32 and PT 36. The annulus spacers 48 maintain the gap between the PT 36 and the corresponding CT 32, while allowing passage of annulus gas through and around the annulus spacers 48.

[0062] As also shown in FIG. 2, each end of each fuel channel assembly 28 is provided with an end fitting assembly 50 located outside of the corresponding tube sheet 18. Each end fitting assembly 50 includes an end fitting body 57 and an end fitting liner 58. At the terminal end of each end fitting assembly 50 is a closure plug 52. Each end fitting assembly 50 also includes a feeder assembly 54. The feeder assemblies 54 feed reactor coolant into or remove reactor coolant from the PTs 36 via feeder tubes 59 (FIG. 1). In particular, for a single fuel channel assembly 28, the feeder assembly 54 on one end of the fuel channel assembly 28 acts as an inlet feeder, and the feeder assembly 54 on the opposite end of the fuel channel assembly 28 acts as an outlet feeder. As shown in FIG. 2, the feeder assemblies 54 can be attached to the end fitting assemblies 50 using a coupling assembly 56 including a number of screws, washers, seals, and / or other types of connectors. The lattice tube 65 (described above) encases the connection between the end fitting assembly 50 and the PT 36 containing the fuel assemblies 40. Shielding ball bearings 66 and cooling water surround the exterior of the lattice tubes 65, which provides additional radiation shielding.

[0063] A positioning hardware assembly 60 and bellows 62 are also coupled to each end fitting assembly 50. The bellows 62 allows the fuel channel assemblies 28 to move axially - a capability that can be important where fuel channel assemblies 28 experience changes in length over time, which is common in many reactors. The positioning hardware assemblies 60 can be used to set an end of a fuel channel assembly 28 in either a locked configuration that fixes the axial position, or an unlocked configuration. The positioning hardware assemblies 60 are also coupled to the end shield 64. The illustrated positioning hardware assemblies 60 each include a rod having an end that is received in a bore of the respective end shield 64. In some embodiments, the rod end and the bore in the end shield 64 are threaded. Again, it should be understood that although a CANDU™-type reactor is illustrated in FIG. 1 and FIG. 2, the invention may also apply to other types of reactors, including reactors having components that are similar to those illustrated in FIG. 1 and FIG. 2.

[0064] Exemplary Removal Process for Retubing.

[0065] FIG. 3 illustrates a flow chart of a removal process for retubing a nuclear reactor according to some embodiments. Similar processes may be carried out for the decommissioning process. As shown in FIG. 3, the removal process starts with shutting down the reactor 6 (at step S70) and preparing the vault for retubing (at step S72). These steps can include various activities, such as defueling the reactor 6, draining the reactor’s primary heat transport system, installing an isolation bulkhead, installing and removing a temporary platform on a reactor area bridge to drain the fuel channel assemblies 28, removing the reactor area bridge, upgrading one or more vault cranes, vacuum drying one or more of the reactor’s heat transport systems, and other draining, drying, and ventilation activities. It should be understood that the steps needed to shut down the reactor 6 and prepare the vault can vary based on the specific configuration of the reactor.

[0066] At step S76, material handling equipment, a retube tooling platform (“RTP”) 611 , and other tool and equipment supports are installed. The RTP 611 is an adjustable platform upon which much of the fuel channel component removal operations are performed. In some embodiments, the RTP 611 is a stand-alone machine that does not rely on existing plant structures for positioning or movement. Therefore, minimal structural bracing to existing plant structures may be needed to install the RTP 611 , and any bracing used is only temporarily installed. In some embodiments, reactor area bridge columns are used to install the RTP 611. In other embodiments, four new columns are used. The four new columns can be precision-located within the vault, relative to the center point of the calandria vessel 10, using laser tracker technology. By positioning the columns in this way, the RTP 611 is positioned to the as-built location of the calandria vessel 10 (including pitch and yaw), which may reduce the time spent during each transition to a new removal step or series to align tooling, and provides a precision tooling base that may permit the use of high accuracy indexing to each lattice site.

[0067] Installed and mounted on the RTP 611 , and serving as the basis for tool delivery during the removal phase, are one or more heavy work tables (“HWTs”). The HWTs provide a platform that supports retubing equipment. At the completion of a removal process, the HWTs can be replaced with installation work tables (“IWTs”).

[0068] In preparation for removing the fuel channel assemblies 28, closure plugs 52 and positioning hardware assemblies 60 may be removed from the fuel channel assemblies 28 (at steps S78, S80). Also, at step S82, feeder assemblies 54 may be disconnected from the endfittings 50. These removals can be performed using manually installed and operated tooling. In some embodiments, two or more crews per reactor face can be used to perform these removals and disconnects. These series can be full face series; however, the manual nature and size of the tooling needed for these series permits overlap between these series.

[0069] As shown in FIG. 3, to remove the fuel channel assemblies 28, the bellows 62 may also be severed (at step S84). To sever the bellows 62, a fuel channel annulus bellows cutting tool can be installed on the HWT (e.g., supported by the RTP). The bellows 62 are typically cut from an end fitting attachment at the bellows flange. The PTs 36 are also severed (at step S86) using a PT severing tool. The PTs 36 are typically severed within the boundary of the end fitting 50 enveloping the PT 36. However, the PTs 36 can be severed at different positions, including the center of the PT 36. The reach of the PT severing tool can be modified as needed to cut the PTs 36 at the desired location(s).

[0070] As mentioned above, the removal pallet system may be used to remove the end fittings 50 (at step S88). To perform this removal process in some embodiments, the pallet starts with an end fitting gripper mounted on the end of a chain drive. A receiving flask may be loaded onto the pallet from above using an overhead vault crane. The rigid chain system advances through the center of the receiving flask to grip the end fitting 50, and then draws the end fitting 50 into the receiving flask. In some embodiments, no operators are required on the RTP 611 during end fitting removal. However, the equipment can be shielded, and local control can be supported so that direct line-of-sight with the equipment may be accommodated. Removal of full flasks and the installation of empty flasks can occur while the RTP 611 is at the “home” position, which is level with the vault floor. Once the removal system is prepared, the RTP 611 can be elevated to the required row, and tooling can be operated to remove the end fittings.

[0071] Once the end fittings 50 are removed and placed into a receiving flask, they can be transported for disposal. For example, as described above, a trolley system or automated guided vehicle can be installed in the reactor vault that extends through the airlock, and is used to transfer removed components out of the vault. The systems may eliminate or reduce many hazardous involved in manually-operated transfers.

[0072] As illustrated in FIG. 3, after end fitting removal, the PTs 36 may be removed (at step S90) by pushing on the PT 36 from one end of the reactor with a push tool mounted on the removal pallet on the opposite side of the reactor. A containment flask may be mounted on the same palletas used with the end fittings 50. The containment flask can be used to minimize the spread of contamination from the PT 36, and to capture any fragments of the annulus spacers 48. The containment flask can be pushed into the lattice tube 65 up to the CT 32. The pushing of the PT 36 can be performed from the opposite side of the reactor with a trailing bung that sweeps the annulus spacer 48 fragments into the containment. Cleaning of the annulus spacer 48 fragments from the flared area of the CT 32 can also be performed by this sweep.

[0073] Either before or after PT removal, calandria tube inserts 34 can be released and removed (at step S92). After the calandria tube inserts 34 and PTs 36 are removed, the CTs 32 are removed (at step S94) and the removal process is complete.

[0074] Lattice Sleeve and Shield Plug Assembly.

[0075] Upon removal of the end fitting during retube or decommissioning (e.g., at step S88 ofFIG. 3), a lattice sleeve (Thumbtack) and its shield plug can be installed into the lattice site to provide shielding at the fueling machine side tube sheet. The Thumbtack can also act as a guide for tooling to be inserted into the lattice site to perform further removal operations of the pressure tube, calandria tube insert and calandria tube. This assembly can be installed and removed using an automated system (described in greater detail below).

[0076] The Thumbtack can be held in place using a stud, which can be fastened to the tapped hole in the fuel machine side tube sheet. The Thumbtack and its shield plug can be installed into the lattice site upon removal of the end fitting. The Thumbtack can be installed with the bellows present. During decommissioning, where the bellows may be removed with the end fitting, the Thumbtack and its shield plug assembly can be modified to ensure the assembly can maintain its functionality and reliability.

[0077] FIG. 4A illustrates a perspective view of a shield plug 400, according to some embodiments.

[0078] The shield plug 400 can be made up of a flange 402 and a plug 404. In some embodiments, the shield plug 400 (or one or more of its components) may comprise a material that can attenuate radiation. In some embodiments, the shield plug 400 (or one or more of its components) may comprise steel or tungsten. Such materials may enable, for example, workers to work in front of the face for longer periods of time. The flange 402 may comprise a cylindrical portion, or other geometrical structure, configured to insert into the lattice sleeve 412 which maybe inserted into an opening of a fuel channel after the removal of the end fitting. Flange 402 may comprise, at a first end, components to allow tooling to couple to, and interoperate with, flange 402 for insertion or removal of shield plug 400. Flange 402 may comprise, at a second end, a plug 404. In some embodiments, the flange may comprise a thickness configured to attenuate radiation at, for example, the first end. In some embodiments, the thickness of the first end may be two or more inches. In some embodiments, the shield plug 400 may be configured with smaller caps. Such embodiments may be suitable where full radiation attenuation is not required. The plug 404 may comprise materials that, upon insertion into the fuel channel, may prevent the leak of radioactive materials and / or the transmission of radiation. The plug 404 may, for example, comprise a solid steel plug. In some embodiments, plug 404 may have a diameter sized to friction fit within a channel defined by sleeve 412 of thumbtack 410.

[0079] FIG. 4B illustrates a perspective view of a Thumbtack 410 with the shield plug 400 inserted therein, according to some embodiments.

[0080] The Thumbtack 410 may comprise a lattice sleeve assembly 411 with a shield plug 400 therein inserted. The lattice sleeve assembly 411 can comprise a lattice sleeve 412 and a face 414. The lattice sleeve 412 can be configured for insertion into the lattice site, specifically a lattice tube of a nuclear reactor, once the end fitting is removed. In some embodiments, the lattice sleeve 412 can be configured to couple to the lattice site even if the bellows are still there attached. In an example, lattice sleeve 412 may extend through the bellows into the lattice site.

[0081] The face 414 can include an opening to receive the shield plug 400. In some embodiments, such as those illustrated in the figure, the opening can be asymmetric. Such configurations may be advantageous when there are physical features on, for example, the reactor face around which the Thumbtack 410 must fit. In some embodiments, the Thumbtacks may include openings which are adjustable to accommodate differing reactor configurations. The face 414 may also include an identification number 416 and an alignment indicia or marking 418. The identification number 416 may include an identifier for a person or system to later identify the lattice site based on that number alone. The identification number 416 can take many forms such as a number, a barcode, a QR code, or some other symbology. The identification number 416 may also use some other identification technology such as RFID. The identification number 416 may also be inscribed in such a way to be visible to certain machinery (e.g., RFID, ultraviolet markings, etc.). The alignment indicia or marking 418 can be configured to provide orientating markings for, for example, an automated machine. For example, a camera onboard a machinemay be configured to identify the alignment indicia or marking 418 and precisely identify the distance from and orientation relative to the face 414 to assist in later movement activities (e.g., to find the center of the thumbtack). In some embodiments, the alignment indicia or marking 418 may include a fiducial marking. In some embodiments, other alignment systems (e.g., vision alignment systems) can be implemented.

[0082] The Thumbtack 410 may include a stop tube 422 defining a threaded stud 420 within the tube. The stud 420 may comprise a threaded end 424 for coupling to an end shield 64. The stud 420 may secure the Thumbtack 410 in a fixed position and desired orientation when the Thumbtack 410 is inserted into a lattice tube. The stud 420 can be pushed until the stud threaded end 424 contacts the end shield. The stud 420 may be fastened to a tapped hole on the fueling machine side tube sheet.

[0083] As shown, thumbtack 410 may comprise a shipping tab 426 that holds the shield plug 400 inside the Thumbtack 410 during, for example, transportation and lifting operations. Once installed, this shipping tab 426 can be manually removed. The installation and removal can be performed by an automated tool.

[0084] FIG. 4C shows an alternative face 414 of the Thumbtack 410, according to some embodiments.

[0085] In some embodiments, the shield plug 400 can be located symmetrically within the Thumbtack face 414, as shown in FIG. 4C. Symmetric Thumbtacks 410 may be easier to manufacture. The shield plug 400 can be installed using, for example, a lattice sleeve handling tool described herein and manually fastened to the tube sheet.

[0086] Furthermore, the face 414 shown in FIG. 4C includes circular fiducial markings 418. These circular fiducial markings 418 may be easier to detect by cameras as part of a vision alignment system or they may otherwise improve the performance of the vision alignment system.

[0087] According to an aspect, there is provided a lattice sleeve and shield plug assembly 410. The assembly 410 includes a shield plug 400 comprising a flange 402 and a plug 404 and a lattice sleeve 411. The lattice sleeve 411 includes a sleeve 412 to engage a fuel channel after removal of an end fitting, a face 414 with an opening configured to receive the shield plug 400 through the face 414 and into the fuel channel, and a stud 420 configured to insert through a stop tube 422 through to an end shield.

[0088] In some embodiments, the lattice sleeve 411 further comprises at least one of a threaded stud 420 and a stop tube 422.

[0089] In some embodiments, the opening is symmetric relative to the face 414.

[0090] In some embodiments, the opening is asymmetric relative to the face 414.

[0091] In some embodiments, the lattice sleeve 411 further includes at least one alignment indicia or marking 418.

[0092] In some embodiments, the at least one alignment indicia or marking 418 includes at least one fiducial markings.

[0093] In some embodiments, the lattice sleeve 411 further includes an identification number 416.

[0094] In some embodiments, at least one of the shield plug 400 and a front face 414 of the sleeve 411 includes a radiation attenuating material.

[0095] In some embodiments, the radiation attenuating material includes steel.

[0096] In some embodiments, the radiation attenuating material includes tungsten.

[0097] In some embodiments, at least one of the shield plug 400 and a front face 414 of the sleeve 411 includes a thickness of 2 or more inches.

[0098] In some embodiments, the lattice sleeve further includes a shipping tab 426 to secure the shield plug during transportation.

[0099] FIG. 5A illustrates a perspective view of a reactor face with Thumbtacks 502 and 504 installed, according to some embodiments.

[0100] In some embodiments, a modified Thumbtack 502 and 504 may be used for the peripheral channels. In the illustrated example of Thumbtacks 502 and 504 shown in FIG. 5A, lattice sleeve 512 of the Thumbtack 504 can be pushed into the lattice site until the stud 506 or stop tube 522 contacts the end shield. The thumbtack 502 may then be inserted into its peripheral lattice site and secured to the neighboring Thumbtack 504 using a fastener 508 with, for example, a plate and two bolts (one bolt on each Thumbtack 502 and 504 and a plate coupling each bolt)as shown in FIG. 5B. The stud 506 and / or stop tube 522 may have a shorter length than the thumbtack 502, 504, the length of stud 506 and / or stop tube 522 configured to engage a surface of a reactor face when the thumbtack 502, 503 is inserted into a lattice site a desired distance. Such embodiments may be advantageous where the peripheral lattice sites do not share accommodation, for example, the stud and / or stop tube. In such embodiments, the peripheral sites may be sealed using a modified Thumbtack 502 and secured to a neighbouring Thumbtack 504 which can secure the Thumbtack 502 in the proper position (e.g., depth) and orientation (e.g., by restraining axial movement). Shield plug 500 may be inserted into the Thumbtack 502, 504 to seal the lattice site.

[0101] In some embodiments, the lattice sleeve 502 further includes a tab 508 configured to secure the lattice sleeve 502 to a neighbouring lattice sleeve 504.

[0102] Handling Tool.

[0103] FIG. 6A illustrates a perspective view of a lattice sleeve handling tool 600, according to some embodiments. FIG. 6B illustrates a perspective view of the lattice sleeve handling tool 600 of FIG. 6A without the casing 620, according to some embodiments.

[0104] The lattice sleeve handling tool 600 may comprise a carriage 601a. The carriage 601a may be coupled to a payload such as a head, a camera (e.g., a side-facing camera), and a tool for performing an operation in the nuclear reactor e.g. a ram. The lattice sleeve handling tool 600 can be used to install, remove, and re-install other payloads such as Thumbtacks (and their shield plugs). The lattice sleeve handling tool 600 can be designed with self-alignment mechanisms (e.g., a balancer and centralizer) capable of compensating for, for example, positional and annular misalignment. The carriage 601a may comprise an arm 607a equipped with a gripping member 608a to couple to a payload to be inserted and / or removed from a lattice site. The tool 600 may further comprise a second carriage 601 b with a second arm 607b equipped with a gripping member 608b. The gripping member 608a, 608b may grip either the outside or inside of a payload. Payloads may be rotated about a longitudinal axis using a cam system. Rotating the payload may allow rotating of a camera for inspecting the lattice tube, pressure tube, and / or calandria tube. As illustrated in the FIG. 6A, the carriage 601a is in an extended position. Carriages 601a, 601b may be configured to move in an x-direction to extend or retract from a reactor face. In the extended position, the gripping members 608a, 608b may deploy a payload into a lattice tube of the nuclear reactor. Carriages 601a, 601 b may also each be configured to move in the y-direction using anactuator 609 (see FIG. 6B). The actuator 609 (e.g., a rack and pinion drive or screw drive) may drive the carriages 601a, 601b in one or more of x-direction and y-direction. In an example, carriages 601a and 601 b may be coupled to different payloads which can be deployed to a lattice site. Continuing the example, a carriage 601 a may extend to deploy a first payload, e.g., a camera, to a lattice site. The carriage 601a may then retract in the x-direction clearing a path for another carriage 601 b to access the lattice site. The other carriage 601b may move in the y-direction to align a second payload with the lattice site and then move in the x-direction to extend toward to the lattice site to deploy the second payload. The lattice sleeve handling tool 600 may be controlled by a controller 2001 .

[0105] In some embodiments, the lattice sleeve handling tool 600 may only comprise one carriage 601a. Such embodiments may be used in conjunction with another handling tool (e.g., other equipment handling tools) to insert a payload (e.g., a camera, guide sleeves, gauges, scanners, thumbtack, shield plug, etc.) once the shield plug of the Thumbtack is removed using the lattice sleeve handling tool 600. Finally, the lattice sleeve handling tool 600 may replace the shield plug, for example, after the payload has been removed or while leaving the payload inside the lattice site. Some embodiments may be used in conjunction with manual insertion of a payload. Some embodiments may be used in conjunction with a second lattice sleeve handling tool 600 which may be the same or different from the first lattice sleeve handling tool 600. In such embodiments, one lattice sleeve handling tool may remove the shield plug of the Thumbtack and the second lattice sleeve handling tool 600 may deliver a payload into the lattice site. Finally, the first lattice sleeve handling tool 600 may replace the shield plug, for example, after the payload has been removed or while leaving the payload inside the lattice site.

[0106] In some embodiments, the lattice sleeve handling tool 600 may replace a first payload (e.g., the shield plug) with a second payload (e.g., a camera, guide sleeves, gauges, scanners, etc.). In such embodiments, the lattice sleeve handling tool 600 may be configured to remove the shield plug of a Thumbtack using the gripping member 608a. The gripping member 608a and / or the whole carriage 601a may retract in the x-direction into the tool 600. The shield plug may be deposited or otherwise removed from the carriage 601a and replaced with the second payload. Carriage 601a and / or gripping member 608a may then extend to insert / deposit the first payload into the lattice site. Once finished the gripping member 608a and / or carriage 601a may be retracted again (with or without the first payload depending on whether it was to be deposited or removed from the lattice site). Optionally, the first payload may be removed from gripping member608a. Gripping member 608a may then be coupled to shield plug after which carriage 601a may extend to insert the shield plug back into the Thumbtack.

[0107] In some embodiments, the lattice sleeve handling tool 600 and / or components of the lattice sleeve handling tool 600 may be configured to be operated manually. For example, the gripping member 608a may be provided as part of a manual tool used by an operator to remove a shield plug from the Thumbtack and / or deliver a payload into the Thumbtack.

[0108] In some embodiments, the lattice sleeve handling tool 600 may comprise a second carriage 601 b. The second carriage may generally share the same description, components, and variations as described for carriage 601a. The two carriages 601a and 601b may be the same or different from one another. Embodiments with a second carriage 601b may enable the removal of one payload (e.g., the shield plug of a Thumbtack) with, for example, the first carriage 601a, and the delivery of another payload (e.g., a camera, guide sleeves, gauges, scanners, etc.) with, for example, the second carriage 601b. In such embodiments, two gripper heads can be delivered via two carriages 601a and 601b, which can be mounted, for example, on linear rails and powered by a servo drive working on, for example, a rack and pinion system. The carriages can move up and down by, for example, y-axis servo motors that are, for example, identically designed and are driven synchronously. Such embodiments can enable the removal of one payload (e.g., a shield plug) with one gripper and insertion of another payload with the other gripper.

[0109] According to an aspect, there is provided a tool 600 to handle a shield plug. The tool 600 including a carriage 601a comprising an arm 607a equipped with a gripping member 608a.

[0110] In some embodiments, the tool 600 is configured to remove a shield plug from a lattice sleeve using the gripping member 608a and insert the shield plug into the lattice sleeve using the gripping member 608a.

[0111] In some embodiments, the tool 600 further includes a second carriage 601 b including a second arm 607b equipped with a second gripping member 608b. The tool 600 is configured to insert or remove a payload from a lattice site when the shield plug is removed.

[0112] In some embodiments, the tool 600 is configured to insert a payload into a lattice site after the shield plug removal.

[0113] In some embodiments, the tool 600 is further configured to align with a lattice sleeve using an alignment indicia or marking on face 414 of the thumbtack.

[0114] In some embodiments, the tool 600 is configured to install at least one of the lattice sleeve and shield plug assembly described above at a lattice site, the shield plug described above in the lattice sleeve described above, and the shield plug described above at the lattice site.

[0115] In some embodiments, the carriage is a first carriage 601a and the tool 600 includes a second carriage 601 b and a controller. The controller is configured to couple a first payload to the gripping member 608a of the first carriage 601a, move the first carriage 601a to toward a lattice site of nuclear reactor to insert the first payload into a lattice tube, retract the gripping member 608a of the first carriage 601a from the lattice tube, move the second carriage 601b to align a second payload coupled to a gripping member 608b of the second carriage 601b with the lattice tube, and move the second carriage 601 b toward the lattice site to insert the second payload into the lattice tube.

[0116] In some embodiments, the controller is configured to release a first payload in the lattice tube.

[0117] According to an aspect, there is provided a tool 600 to handle a payload. The tool 600 includes a first arm 607a equipped with a first gripping member 608a configured to couple to an exterior of a first payload, a second arm 607b equipped with a second gripping 608b member configured to couple to an exterior of a second payload, and an actuator to selectively extend the first arm 607a and second arm 607b towards or away from a face of a nuclear reactor, e.g. toward or away from a lattice tube of the nuclear reactor.

[0118] In some embodiments, the tool 600 is configured to remove a shield plug from a lattice sleeve using the first gripping member 608a by coupling to an exterior of the shield plug and retracting the shield plug and insert the shield plug into the lattice sleeve using the first gripping member 608a by inserting the shield plug and decoupling from the exterior of the shield plug.

[0119] In some embodiments, the tool 600 is configured to insert the first or second payload into a lattice site after the shield plug removal using the second gripping member 608b by inserting the payload.

[0120] In some embodiments, the tool 600 is further configured to align with a lattice sleeve using an alignment indicia or marking on a face 414 of the thumbtack detected with a camera.

[0121] In some embodiments, the tool 600 includes a controller 2001 configured to couple a first payload to the first gripping member 608a, move the first arm 607a to toward a lattice site ofa nuclear reactor to insert the first payload into a lattice tube, retract the first gripping member 608a from the lattice tube, move the second arm 607b to align the second payload coupled to the second gripping member 608b with the lattice tube, move the second arm 607b toward the lattice site to insert the second payload into the lattice tube. In an example, the first payload inserted into a lattice tube may be a camera for inspecting the lattice tube and / or other components of the nuclear reactor; and the second payload may be a lattice sleeve and shield plug assembly. The camera may be removed by the by the first gripping member from the lattice tube prior to inserting the second payload into the lattice tube.

[0122] In some embodiments, the tool 600 is configured to install at least one of the lattice sleeve and shield plug assembly at a lattice site, the shield plug in the lattice sleeve, and the shield plug at the lattice site.

[0123] In some embodiments, the controller 2001 is configured to release the first payload in the lattice tube.

[0124] Some embodiments further include a controller 2001 configured to sent data to the first and second gripping member 608a. 608b to insert the first or second payload.

[0125] Alternative Tooling

[0126] FIG. 7A illustrates a perspective view of an alternative lattice sleeve handling tool 700, according to some embodiments.

[0127] In the alternative tool 700, only one carriage 601a is provided with an arm 607a equipped with a gripping member 608a. The tool 700 further includes lifters 702. The lifters may be movable between a down position (as illustrated) in the path A-A of the carriage 601a and an up position out of the path A-A.

[0128] In this embodiment, the lifters 702 may or may not be equipped with a payload to be delivered into a lattice tube site. Lifters 702 may initially be in their up position, e.g. positioned radially away from path A-A of carriage 601a as shown in FIG. 7B, such that lifters 702 are not in the way of the carriage 601a. The carriage 601a and arm 607a may advance along path A-A axially extending towards the Thumbtack and the arm 607a equipped with the gripping member 608a which may be deployed to couple to the shield plug of the Thumbtack 502 as shown in FIG. 7B. The carriage 601a and / or the arm 607a equipped with the gripping member 608a may then retract behind one of the lifters 702. Lifter 702 may then lower and the carriage 601a and / or thearm 607a equipped with the gripping member 608a may advance into the lifter 702. The gripping member 702 may then uncouple from the shield plug to release it into the lifter 702. Lifter 702 may then move into the up position, e.g. radially away from path A-A of carriage 601a as shown in FIG. 7B, out of the way of the carriage 601 a. Carriage 601 a and / or arm 607a equipped with the gripping member 608a may then move into position to receive a payload from another lifter 702. The lifter 702 equipped with the payload (e.g., a camera) may lower into path A-A of the carriage 601a. The carriage 601a and / or the arm 607a equipped with the gripping member 608a may advance into the lifter 702. The gripping member 608a may then couple to the payload to retrieve it from the lifter 702. The lifter 702 may then move into the up position out of the way path A-A of carriage 601a. The tool 700 may then deliver the payload into the lattice tube site (as described above). For example, the tool 700 may insert a camera and rotate it about the axis to inspect the lattice tube site. Once done, the carriage 601a may retract and replace the payload onto the payload’s lifter 702 and retrieve the shield plug from the shield plug’s lifter 702 and then re-insert the shield plug, uncouple the gripping member 608a from the shield plug and complete the operation.

[0129] According to an aspect, there is provided a tool 700 to handle a payload. The tool 700 includes an arm 607a equipped with a gripping member 608a configured to couple to an exterior or interior surface of a payload, an actuator to extend the arm towards a face of a nuclear reactor, a first lifter 702 configured to receive a first payload from the gripping member 608a or deliver the first payload to a gripping member 608a, and a second lifter 702 configured to receive a second payload from the gripping member 608a or deliver the second payload to a gripping member 608a. The first and second lifter 702 are each configured to move between a down position in path A-A of the arm 607a equipped with the gripping member 608a and an up position out of the path A-A of the arm 607a equipped with the gripping member 608a.

[0130] Alternative Design - Contamination Plates.

[0131] In some embodiments, a contamination plate 430 may be used to provide additional shielding. This plate can be installed to sealed over the face of the thumbtack and / or lattice tube (e.g., by seal weld). This can be a manual operation or an automated process (depending on, for example, the radiation dosage). One or more channels / lattice tubes can be sealed at a time. A delivery tool can install the shield plug and a second tool can install and bolt the contamination plate on to the thumbtack and shield plug. This operation can seal multiple sites at a time. The contamination plates may provide additional shielding from, for example, alpha radiation (e.g., toprevent fuel residue from escaping and emitting alpha particles). It may also be beneficial to attenuate and control other forms of radiation.

[0132] In some embodiments, the lattice sleeve further includes a contamination plate.

[0133] Alternative Design - Contamination Fixative.

[0134] In some embodiments, shield plugs may be inserted into the lattice tube after drainage and removal of the end fittings to block holes in the end shield and re-establish the end shield to, for example, full function. The vessel may then be filled with grout mix, covering the outside with a contamination fixative and side cover. The system can then be moved to a separate building for storage and later dismantling. Such embodiments may be of particular use for end of life solutions (e.g., decommissioning work) wherein any radioactive material can be sealed within to prevent contamination.

[0135] Alternative Design - Barbed Plugs and Smaller Caps.

[0136] In some embodiments, the shield plug may be configured to go into a fuel channel assembly after the end fitting is pulled out. For example, a shield plug may be barbed such that it can be inserted into a lattice tube once the end fitting is removed, but not easily removed from the lattice tube once inserted. Such embodiments may be suitable in situations where access to the lattice site is not later required. As shown in FIG. 4A, barbs 405 may engage with the interior of the lattice site once inserted, e.g., from frictional forces or by barb members being extended into contact with the lattice tube. In such embodiments, there may be no need for the lattice sleeve as the barbs may hold the shield plug in place. Such embodiments may be of particular use for end of life solutions (e.g., decommissioning work).

[0137] According to an aspect, there is provided a shield plug including a flange, a plug, and one or more barbs configured to engage the interior of a lattice site.

[0138] In some embodiments, the shield plug includes a radiation attenuating material.

[0139] In some embodiments, the radiation attenuating material includes steel.

[0140] In some embodiments, the radiation attenuating material includes tungsten.

[0141] In some embodiments, the shield plug has a thickness of 2 or more inches.

[0142] Controller.

[0143] FIG. 8 shows a generalized schematic view of example system 2000 for controlling a lattice sleeve handling tool 600. System 2000 may comprise controller 2001 , described herein. The controller 2001 includes a processor 2002 configured to implement processor readable instructions that, when executed, configure the processor 2002 to conduct operations described herein. The processor 2002 may be a microprocessor or microcontroller, a digital signal processing (DSP) processor, an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, a programmable read-only memory (PROM), or combinations thereof. The controller 2001 may include a communication interface 2004 to communicate with other computing or sensor devices, to access or connect to network resources, or to perform other computing applications by connecting to a network (or multiple networks) capable of carrying data. In some examples, the communication interface 2004 may include one or more busses, interconnects, wires, circuits, and / or any other connection and / or control circuit, or combination thereof. The communication interface 2004 may provide an interface for communicating data between the system 2000 and a display 2015.

[0144] The controller 2001 may also comprise connections for communicating with any of a lattice sleeve handling tool 600, a carriage 601a, a second carriage 601b, a head 602, a tool for performing an operation in the nuclear reactor, e.g. ram 604, a camera 606, a platform RTP 611 , a gripping member 608a, 608b, according to this disclosure to transmit setpoint(s) or receive data such as position, orientation, and lattice sleeve handling tool status, among other data.

[0145] Controller 2001 may be coupled to a data system 2014 for storing system data and / or may be configured to communicate with cloud services such as iCloud, Dropbox, Google clouds, or any other digital data servers. The data system 2014 may also comprise a universal asynchronous receiver-transmitter (LIART) to allow communication with other devices, e.g., a smartphone or a computer, for transmitting data for analysis and / or storage. LIART may include or be coupled to a wireless transceiver for wireless communication with such other devices, e.g., by way of infra-red, Bluetooth, Wi-Fi, or the like. The network 2500 may include any wired or wireless communication path, such as an electrical circuit. In some embodiments, the network 2500 may include one or more busses, interconnects, wires, circuits, and / or any other connection and / or control circuit, or a combination thereof. In some embodiments, the network 2500 may include a wired or a wireless wide area network (WAN), local area network (l_AN), a combinationthereof, or the like. In some embodiments, the network 2500 may include a Bluetooth® network, a Bluetooth® low energy network, a short-range communication network, or the like.

[0146] The controller 2001 may include memory 2006. The memory 2006 may include one or a combination of computer memory, such as static random-access memory (SRAM), randomaccess memory (RAM), read-only memory (ROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like.

[0147] The memory 2006 may store an application 2012 including processor readable instructions for conducting operations described herein. In some examples, the application 2012 may include operations for controlling a lattice sleeve insert tool according to this disclosure.

[0148] In an embodiment, the application 2012 may include operations for: extending a head of a lattice sleeve insert tool into an opening defined by a lattice sleeve assembly; extending grips into contact with an inner diameter of the sleeve; moving the lattice sleeve assembly; releasing the grips from thumbtack. In another embodiment, the application 2012 may include operations for: extending a head of a lattice sleeve insert tool around a flange of a shield plug; extending grips into contact with the flange; moving the shield plug into the lattice sleeve assembly.

[0149] In another embodiment, the application 2012 may include operations for: extending a head of a lattice sleeve insert tool around a flange of a shield plug; extending grips into contact with the flange; moving the shield plug out of a lattice sleeve assembly.

[0150] In another embodiment, the application 2012 may include operations for moving a first carriage to extend or retractor from lattice site at a nuclear reactor face. In the extended position, the application 2012 may cause the gripping member 608 to release a first payload into a lattice tube. The first carriage may retract from the lattice site to vacate a space for a second carriage. The application 2012 may cause the second carriage to move into alignment with the lattice site; and then extend a second payload coupled to a gripping member of the second carriage into the lattice tube. The gripping member of the second carriage may then release to the second payload.

[0151] In another embodiment, the application 2012 may include operations for optically scanning fiducial markings 418 to identify a centroid position of a channel defined by sleeve 412 of thumbtack. Applicant 2012 may also include operations for moving a gripping member coupled to a payload to align the payload with the centroid position for insertion of the payload into thechannel. Applicant 2012 include operations for moving the gripping member to position the payload into the channel.

[0152] Implementation Details.

[0153] The foregoing discussion provides many example embodiments. Although each embodiment represents a single combination of inventive elements, other examples may include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, other remaining combinations of A, B, C, or D, may also be used.

[0154] The term “connected” or "coupled to" may include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0155] The singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise. The term "and / or" means any one of the items, any combination of the items, or all of the items with which this term is associated.

[0156] Although the embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope as defined by the appended claims.

[0157] Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

[0158] As can be understood, the examples described above and illustrated are intended to be exemplary only. The scope is indicated by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A lattice sleeve and shield plug assembly, the assembly comprising: a shield plug comprising a flange and a plug; and a lattice sleeve comprising: a sleeve to engage a fuel channel after removal of an end fitting; a face with an opening configured to receive the shield plug through the face and into the fuel channel; and a stud configured to insert through a stop tube through to an end shield.

2. The assembly of claim 1, wherein the lattice sleeve further comprises at least one of a threaded stud and a stop tube.

3. The assembly of any one of claims 1-2, wherein the opening is symmetric relative to the face.

4. The assembly of any one of claims 1-2, wherein the opening is asymmetric relative to the face.

5. The assembly of any one of claims 1-4, wherein the lattice sleeve further comprises: a tab configured to secure the lattice sleeve to a neighbouring lattice sleeve.

6. The assembly of any one of claims 1-5, wherein the lattice sleeve further comprises a contamination plate.

7. The assembly of any one of claims 1-6, wherein the lattice sleeve further comprises a shipping tab to secure the shield plug during transportation.

8. The assembly of any one of claims 1-7, wherein the lattice sleeve further comprises at least one alignment indicia or marking.

9. The assembly of claim 8, wherein the at least one alignment indicia or marking comprises at least one fiducial markings.

10. The assembly of any one of claims 1-9, wherein the lattice sleeve further comprises an identification number.

11. The assembly of any one of claims 1-10, wherein at least one of the shield plug and a front face of the sleeve comprises a radiation attenuating material.

12. The assembly of claim 11 , wherein the radiation attenuating material comprises steel.

13. The assembly of claim 11 , wherein the radiation attenuating material comprises tungsten.

14. The assembly of any one of claims 1-13, wherein at least one of the shield plug and a front face of the sleeve comprises a thickness of 2 or more inches.

15. A shield plug comprising: a flange; a plug; and one or more barbs configured to engage the interior of a lattice site.

16. The assembly of claim 15, wherein the shield plug comprises a radiation attenuating material.

17. The assembly of claim 16, wherein the radiation attenuating material comprises steel.

18. The assembly of claim 16, wherein the radiation attenuating material comprises tungsten.

19. The assembly of any one of claims 15-18, wherein the shield plug comprises a thickness of 2 or more inches.

20. A tool to handle a payload, the tool comprising: a first arm equipped with a first gripping member configured to couple to an exterior of a first payload; a second arm equipped with a second gripping member configured to couple to an exterior of a second payload; andan actuator to selectively extend the first arm and second arm towards a face of a nuclear reactor.21 . The tool of claim 20, wherein the tool is configured to: remove a shield plug from a lattice sleeve using the first gripping member by coupling to an exterior of the shield plug and retracting the shield plug; and insert the shield plug into the lattice sleeve using the first gripping member by inserting the shield plug and decoupling from the exterior of the shield plug.

22. The tool of claim 21 , wherein the tool is configured to: insert the first or second payload into a lattice site after the shield plug removal using the second gripping member by inserting the payload.

23. The tool of any one of claims 20-22, wherein the tool is further configured to align with a lattice sleeve using an alignment indicia or marking on a face of a thumbtack detected with a camera.

24. The tool of any one of claims 20-23, wherein the tool comprises a controller configured to: couple a first payload to the first gripping member; move the first arm to toward a lattice site of a nuclear reactor to insert the first payload into a lattice tube; retract the first gripping member from the lattice tube; move the second arm to align the second payload coupled to the second gripping member with the lattice tube; move the second arm toward the lattice site to insert the second payload into the lattice tube.

25. The tool of claim 24, wherein the controller is configured to : couple the first or second gripping member to the lattice sleeve and shield plug assembly of any one of claims 1-9 and move the lattice sleeve and shield plug assembly into a lattice site; or couple the first or second gripping member to the shield plug of any one of claims 15-19 and move the shield plug into the lattice site.

26. The tool of claim 24, wherein the controller is configured to release the first payload in the lattice tube.

27. The tool of any one of claims 20-23, further comprising a controller configured to sent data to the first and second gripping member to insert the first or second payload.

28. The tool of any one of claims 20-23, further comprising a controller configured to: optically scan fiducial markings on a thumbtack to identify a centroid position of a channel defined by a lattice sleeve of the thumbtack; move one of the first or second gripping member coupled to a payload to align the payload with the centroid position for insertion of the payload into the channel; move the one of the first or second gripping member to position the payload into the channel.

29. A tool to handle a payload, the tool comprising: an arm comprising a gripping member configured to couple to a payload; an actuator to extend the arm towards a face of a nuclear reactor or withdraw the arm away from the face of the nuclear reactor; a first lifter configured to receive a first payload from the gripping member or deliver the first payload to a gripping member; and a second lifter configured to receive a second payload from the gripping member or deliver the second payload to a gripping member;wherein the first and second lifters are each configured to move between a first position in a path of the arm equipped with the gripping member and a second position out of the path of the arm equipped with the gripping member.

30. The tool of claim 29 comprising a controller configured to: move the first lifter to position the first payload into axial alignment with the arm, the first lifter coupled to the first payload; couple the gripping member to the first payload; extend the arm toward the face of the nuclear reactor to position the first payload in a lattice tube; withdraw the arm from the face of the nuclear reactor to position the first payload on the first lifter; move the first lifter and the first payload out of axial alignment with the arm; move the second lifter to position the second payload into axial alignment with the arm, the second lifter coupled to the second payload; couple the gripping member to the second payload; extend the arm toward the face of the nuclear reactor to position the second payload in a lattice tube.

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