CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional Patent Application No. 63/402,934, filed on August 31, 2022. The entire contents of U.S. Provisional Patent Application No. 63/402,934 are hereby incorporated by reference for all purposes.

FIELD

[0002] This disclosure relates generally to end effectors for use when disassembling a calandria, more specifically to end effectors for use when disassembling a calandria shell of a calandria and methods of using the same.

INTRODUCTION

[0003] The following is not an admission that anything discussed below is part of the prior art or part of the common general knowledge of a person skilled in the art.

[0004] A CANDU (Canada Deuterium Uranium) reactor assembly includes a horizonal cylindrical tank known as a calandria. The calandria typically has about 380 to 480 horizonal fuel channels aligned with an axis of the calandria. The calandria typically also has both vertical and horizontal reactivity control mechanisms oriented perpendicular to the axes of the calandria and fuel channels.

[0005] Decommissioning CANDU reactors necessitates disassembling (deconstructing, segmenting, etc.) the existing calandria. Given the radiation hazard posed by the calandria and associated components, careful consideration needs to be given when designing systems and methods for disassembling a calandria.

[0006] Known methods for disassembling a calandria of a nuclear reactor core involve deploying skilled workers into the nuclear reactor vault which houses the nuclear reactor core. Within the vault, the workers use a plurality of hand-held and/or hand-controlled tools when disassembling the calandria. Although there is no nuclear fuel within the nuclear reactor core during the disassembly process, components of the nuclear reactor core can contain and emit high amounts of radiation. Accordingly, the workers can be subjected to high levels of radiation when performing the calandria disassembly. Further, because of the complexity and scale of the project, workers may be required to be in the vault for long periods of time.

[0007] Accordingly, there is a need for new systems and methods for disassembling a calandria.

SUMMARY

[0008] This summary is intended to introduce the reader to the more detailed description that follows and not to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures.

[0009] In one aspect of this disclosure, which may be used by itself or with one or more of the other aspects disclosed herein, there is provided an end effector for disassembling a calandria, the end effector comprising a main body extending longitudinally along a main body axis between a main body first end and a main body second end, a gripper coupled to the main body proximate the main body second end for gripping a portion of the calandria, and a cutter coupled to the main body proximate the main body first end for cutting the portion of the calandria away from a remaining portion of the calandria.

[0010] In some examples, the cutter is moveable relative to the main body axis.

[0011] In some examples the cutter is mounted on an arm outwardly extending from the main body.

[0012] In some examples the arm is rotatable about the main body axis.

[0013] In some examples the arm is pivotable relative to the main body axis.

[0014] In some examples the cutter is translatable along the arm for adjusting a radial distance between the main body axis and the cutter.

[0015] In some examples the arm is coupled to a rotatable sleeve that encircles an upper portion of the tool body, the rotatable sleeve is rotatable about the upper portion of the main body.

[0016] In some examples the cutter is a plasma torch.

[0017] In some examples the gripper is moveable relative to the main body axis. [0018] In some examples the gripper comprises a first jaw and a second jaw that are moveable between a gripping position and a release position.

[0019] In some examples a hydraulic actuator controls movement of the first jaw and the second jaw between the gripping position and the release position.

[0020] In some examples the gripper is pivotable relative to the main body axis.

[0021] In some examples the main body first end comprises a mount for securing the tool to a drive system.

[0022] In some examples the drive system comprises a gantry and mast.

[0023] In some examples the drive system is operable to rotate the main body.

[0024] According to one aspect, a method of disassembling a calandria comprising gripping a portion of the calandria, cutting the portion of the calandria away from a remaining portion of the calandria, and releasing the portion of the calandria in a waste container.

[0025] In some examples, one or more steps are repeated until a desired amount of the calandria has been disassembled.

[0026] In some examples, one or more steps comprises rotating a cutter for cutting the portion of the calandria away from the remaining portion of the calandria about a gripper for gripping the removable portion of the nuclear calandria.

[0027] In some examples the cutter and the gripper are coupled to a common main body.

[0028] It will be appreciated by a person skilled in the art that a system or method disclosed herein may embody any one or more of the features contained herein and that the features may be used in any particular combination or sub-combination.

[0029] These and other features and advantages of the present application will become apparent from the following detailed description taken together with the accompanying drawings. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the application, are given by way of illustration only, since various changes and modifications within the spirit and scope of the application will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS [0030] For a better understanding of the various embodiments described herein, and to show more clearly how these various embodiments may be carried into effect, reference will be made, by way of example, to the accompanying drawings which show at least one example embodiment, and which are now described. The drawings are not intended to limit the scope of the teachings described herein.

[0031] FIG. 1 is a perspective view of an end effector for use when disassembling a calandria.

[0032] FIG. 2 is a perspective view of a calandria, portions of the calandria shown are removed for illustrative purposes.

[0033] FIG. 3 is a perspective view of a nuclear reactor vault, within the nuclear reactor vault a drive system positioned on a reactivity deck of a casing surrounding a calandria is shown.

[0034] FIG. 4 is a perspective view of the nuclear reactor vault of FIG. 3, a portion of the casing surround the calandria is removed to show the end effector of FIG. 1 operably coupled to the drive system.

[0035] Further aspects and features of the example embodiments described herein will appear from the following description taken together with the accompanying drawings.

DESCRIPTION OF VARIOUS EMBODIMENTS

[0036] Various apparatuses, methods and compositions are described below to provide an example of at least one embodiment of the claimed subject matter. No embodiment described below limits any claimed subject matter and any claimed subject matter may cover apparatuses and methods that differ from those described below. The claimed subject matter are not limited to apparatuses, methods and compositions having all of the features of any one apparatus, method or composition described below or to features common to multiple or all of the apparatuses, methods or compositions described below. It is possible that an apparatus, method or composition described below is not an embodiment of any claimed subject matter. Any subject matter that is disclosed in an apparatus, method or composition described herein that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicant(s), inventor(s) and/or owner(s) do not intend to abandon, disclaim, or dedicate to the public any such invention by its disclosure in this document. [0037] Furthermore, it will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the example embodiments described herein. However, it will be understood by those of ordinary skill in the art that the example embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the example embodiments described herein. Also, the description is not to be considered as limiting the scope of the example embodiments described herein.

[0038] It should be noted that terms of degree such as "substantially", "about" and "approximately" as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of the modified term, such as 1%, 2%, 5%, or 10%, for example, if this deviation does not negate the meaning of the term it modifies.

[0039] Furthermore, the recitation of any numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term "about" which means a variation up to a certain amount of the number to which reference is being made, such as 1%, 2%, 5%, or 10%, for example, if the end result is not significantly changed.

[0040] It should also be noted that, as used herein, the wording "and/or" is intended to represent an inclusive - or. That is, "X and/or Y" is intended to mean X, Y or X and Y, for example. As a further example, "X, Y, and/or Z" is intended to mean X or Y or Z or any combination thereof. Also, the expression of A, B and C means various combinations including A; B; C; A and B; A and C; B and C; or A, B and C.

[0041] The following description is not intended to limit or define any claimed or as yet unclaimed subject matter. Subject matter that may be claimed may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures. Accordingly, it will be appreciated by a person skilled in the art that an apparatus, system or method disclosed in accordance with the teachings herein may embody any one or more of the features contained herein and that the features may be used in any particular combination or sub-combination that is physically feasible and realizable for its intended purpose.

[0042] Recently, there has been a growing interest in developing new systems and methods for disassembling a calandria.

[0043] Turning now to the Figures, referring first to FIG. 1, shown therein is a perspective view of an end effector 100 for use when disassembling a calandria 102. In particular, the end effector 100 may be used, for example, to remove at least a portion of a calandria shell 104 of the calandria 102. As shown in FIG. 2, the calandria shell 104 may extend longitudinally between a first reactor face 106 and a second reactor face (not shown) of the calandria 102. Typically, the calandria shell 104 is made of steel, such as stainless steel.

[0044] Referring back to FIG. 1, the end effector 100 has a main body 110. As shown, the main body 110 may extend along a main body axis 112 between a main body first end 114 and a main body second end 116.

[0045] Coupled to the main body 110, the end effector 100 has a gripper 120. The gripper 120 is for gripping a portion of the calandria 102 (e.g., a portion of the calandria shell 104). Also coupled to the main body 110 is a cutter 122. The cutter 122 is for cutting the portion of the calandria 102 away from a remaining portion of the calandria 102. Specifically, the cutter 122 may cut the portion of the calandria 102 away from the remaining portion of the calandria 102 while the gripper 120 is gripping that portion of the calandria 102. It may be desirable to grip the portion of the calandria 102 with the gripper 120 while cutting that portion away from the remaining portion of the calandria 102 so that that portion of the calandria 102 does not fall and damage the remaining portion of the calandria 102 and/or any nearby equipment.

[0046] After the portion of the calandria 102 gripped by the gripper 120 is cut away from the remaining portion of the calandria 102 by the cutter 122, that portion may be disposed in a waste container. The end effector 100 may be drivingly coupled to a drive system 130 which may be operable to orient/control the end effector 100 to grip and cut the portion of the calandria 102 as well as reposition the end effector 100 to a location where the portion of the calandria 102 cut away from the remaining portion can be disposed.

[0047] In the example illustrated, the cutter 122 is coupled to the main body 110 proximate an upper end 124 of the main body 110. As shown in FIG. 4, the upper end 124 of the main body 110 may be proximate the drive system 130 (e.g., a robotic arm) for controlling movement of the end effector 100. Referring back to FIG. 1, in the example illustrated, the gripper 120 is coupled to the main body 110 proximate a lower end 126 of the main body 110. It will be appreciated that in other examples, the gripper 120 may be coupled to the main body 110 proximate the upper end 124 of the main body 110 (i.e., proximate the drive system 130) and the cutter 122 may be coupled to the main body 110 proximate the lower end 126 of the main body 110.

[0048] Any cutter 122 known in the art capable of cutting the portion of the calandria 102 away from the remaining portion of the calandria 102 may be used. For example, the cutter 122 may be a saw, a grinder, a plasma torch, etc., or any combination thereof. In the example illustrated in FIG. 1, the cutter 122 is a plasma torch.

[0049] The position of the cutter 122 relative to the main body axis 112 may be adjustable. Any means known in the art for moving the cutter 122 relative to the main body axis 112 may be used. It will be appreciated that the portion gripped by the gripper 120 may be irregular in shape, accordingly, it may be desirable for the position of the cutter 122 relative to the main body axis 112 (and the gripper 120) to be adjustable. Further, it may be desirable for the cutter 122 to be moveable relative to the main body 110 so that the cutter 122 may make an extended cut while the main body 110 of the end effector 100 remains stationary.

[0050] Optionally, as shown in FIG. 1, the cutter 122 may be mounted on an arm 140 that extends outwardly from the main body 110. In the example shown, the arm 140 is pivotally coupled to the main body 110 at a pivot joint 142. A hydraulic actuator 144 may be operable to change an angle 146 between the arm 140 and the main body axis 112. That is, the arm 140 may be pivotable relative to the main body 110. It may be desirable for the arm 140 to pivot relative to the main body 110 so that a distance 148, measured parallel to the main body axis 112, between the gripper 120 and the cutter 122 may be adjustable. [0051] In addition, or alternatively, to the cutter 122 being pivotable relative to the main body axis 112, the cutter 122 may be rotatable about the main body axis 112. Any means known in the art for rotating the cutter 122 about the main body axis 112 may be used. For example, as shown in FIG. 1, the cutter 122 (specifically the arm 140 in the example illustrated) may be mounted to a rotatable sleeve 150 that encircles an upper portion 152 of the main body 110. As shown, the rotatable sleeve 150 may comprise a pinion gear 154 drivingly coupled thereto that engages a rack gear 156 drivingly coupled the main body 110. It will be appreciated that in the example illustrated, rotation of the pinion gear 154 (driven by any means known in the art) may cause rotation of the rotatable sleeve 150 (and the arm 140 mounted thereto) about the main body axis 112.

[0052] In addition, or alternatively, to the cutter 122 being pivotable relative to the main body axis 112 and/or the cutter 122 being rotatable about the main body axis 112, the cutter 122 may be translatable relative to the main body axis 112 for adjusting a radial distance 158 between the main body axis 112 and the cutter 122. Any means known in the art for translating the cutter 122 toward and away from the main body axis 112 in the radial direction (i.e., transverse to the main body axis 112) may be used.

[0053] In the example illustrated, the cutter 122 is mounted on a carrier 160. As shown, the carrier 160 may be drivingly coupled to a leadscrew 162 (i.e., the carrier may have a threaded internal bore (not shown) which threadedly engages the leadscrew 162). It will be appreciated that, for example, if the leadscrew 162 is rotated clockwise, the carrier 160 may translate toward a distal end 166 of the arm 140 (i.e., away from the main body 110), whereas if the leadscrew 162 is rotated counterclockwise, the carrier 160 may translate toward the main body 110, or vice versa.

[0054] Still referring to FIG. 1 and as described above, the end effector 100 may include a gripper 120 for gripping the portion of the calandria (e.g., a portion of the calandria shell 104). Any gripper 120 known in the art capable of gripping the portion of the calandria to be cut away from the remaining portion of the calandria may be used. For example, the gripper 120 may be a jaw-type gripper (two-jaw, three-jaw, etc.), a bellow gripper, an O-ring gripper, a needle gripper, hand-type gripper, a vacuum, a magnet, etc., or any combination thereof. [0055] In the example illustrated, the gripper 120 includes a first jaw 170 and a second jaw 172 that are moveable between a gripping position and a release position. Any actuator operable to move the first jaw 170 and second jaw 172 between the gripping position and the release position may be used.

[0056] As shown, a hydraulic actuator 174 may extend between the main body 110 of the end effector 100 and a scissor hinge 176 that extends between the first jaw 170 and the second jaw 172. It will be appreciated that, in the example illustrated, as the hydraulic actuator 174 extends toward a distal end 178 of the gripper 120, first and second arms 180, 182 of the scissor hinge 176 will rotate relative to each other until they are aligned. When the first and second arms 180, 182 of the scissor hinge 176 are aligned, the first and second jaws 170, 172 will be separated. In the example illustrated, when the hydraulic actuator 174 retracts from the position shown in FIG. 1, the first and second jaws 170, 172 will close.

[0057] Optionally, the gripper 120 may be moveable relative to the main body axis 112. Movement of the gripper 120 may or may not be independent from movement of the cutter 122. Any means known in the art for moving the gripper 120 relative to the main body axis 112 may be used.

[0058] In the example illustrated in FIG. 1, the gripper 120 is pivotable relative to the main body axis 112. In the example illustrated, the gripper 120 is pivotally mounted to the main body 110 at a pivot joint 188. As shown, a hydraulic actuator 184 may be operable to pivot the gripper 120 between a first position and a second position. Accordingly, as shown, the gripper 120 may be pivoted independently from movement of the cutter 122.

[0059] In addition, or alternatively, to the gripper 120 being pivotable relative to the main body axis 112, the gripper may be rotatable about the main body axis 112. In the example illustrated, the gripper 120 is not rotatable relative to the main body axis 112. In the example shown in FIG. 1, the main body 110 (with the gripper 120 coupled thereto) may be rotatable relative to the calandria 102 via the drive system 130. That is, the drive system 130 may be operable to rotate the main body 110, and therefore, the gripper 120 may be rotated into a desired position to grip the portion of the calandria 102 to be cut away from the remaining portion of the calandria 102. It will be appreciated that rotation of the main body 110 by the drive system 130 may cause rotation of the cutter 122 and the gripper 120.

[0060] In other embodiments, the gripper 120 may be rotatably mounted to the main body 110.

[0061] Still referring to FIG. 1, in the example illustrated, the main body first end 114 includes a mount 186 for securing the end effector 100 to the drive system 130. In the example illustrated, the mount 186 is detachably attachable to the drive system 130. An example of the end effector 100 shown in FIG. 1 mounted to a drive system 130 is shown in FIG. 4.

[0062] It may be desirable for the mount 186 to be detachably attachable to the drive system 130 so that the drive system 130 can be used to operate multiple end effectors. In other embodiments, the end effector 100 may not be detachably attachable to the drive system 130 and may be an integral component thereof.

[0063] Referring now to FIG. 3, shown therein is an example of a drive system 130 in position to disassemble a calandria 102. Specifically, FIG 3. shows the drive system 130 positioned on a reactivity deck 190 of a casing 192 surrounding a calandria 102 within a nuclear reactor vault 194. The reactivity deck 190 is an upper portion, or deck, of a concrete casing 192 that may surround the calandria 102. In some examples, the reactivity deck 190 supports upper ends of reactivity control units, their mechanisms, shielding, and connecting tubes and cables. In the example illustrated, the drive system 130 includes a mast and gantry.

[0064] When disassembling a calandria 102 using the end effector 100 described above, the following steps may be performed (a) gripping a portion of the calandria 102; (b) cutting the portion of the calandria 102 awayfrom a remaining portion of the calandria 102; and (c) releasing the portion of the calandria 102 in a waste container. Steps (a) to (c) may be repeated until a desired amount of the calandria 102 has been disassembled.

[0065] In some exemplary methods, a first portion of the calandria 102 may be disassembled using the end effector 100 described herein. After the first portion of the calandria 102 has been disassembled the end effector 100 may be detached from the drive system 130 and an alternative end effector may be attached thereto to disassemble a second portion of the calandria 102. Optionally, after the alternative end effector is used to disassemble the second portion of the calandria 102, that end effector may be detached and the end effector 100 described herein may be reattached to the drive system 130 to disassemble a third portion of the calandria 102.

[0066] When operating the end effector 100 to cut away a portion of the calandria 102, the cutter 122 may be rotated about the gripper 120. Optionally, the gripper 120 may remain stationary as the cutter 122 is rotated thereabout.

[0067] While the above description describes features of example embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. For example, the various characteristics which are described by means of the represented embodiments or examples may be selectively combined with each other. Accordingly, what has been described above is intended to be illustrative of the claimed concept and non-limiting. It will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The scope of the claims should not be limited by the preferred embodiments and examples but should be given the broadest interpretation consistent with the description as a whole.