CA3028463C - Methods and apparatus for handling materials for retubing of a nuclear reactor - Google Patents

Abstract

A material handling system for use during retubing of a CANDU reactor is provided. The material handling system comprises a track system comprising a plurality of track sections; and a trolley comprising a cargo bed. The track sections include at least one curved track section. At least two wheel trucks are operatively coupled to the cargo bed, and a guide mechanism for interacting with the track system is provided where at least one of the wheel trucks pivots relative to the cargo bed.

Description

METHODS AND APPARATUS FOR HANDLING MATERIALS FOR RETUBING OF A
NUCLEAR REACTOR
CROSS REFERENCE TO RELATED APPLICATIONS
100011 The present application claims priority to U. S. Provisional Patent Application No.
61/433,398, filed January 17, 2011.
BACKGROUND
100021 The present invention relates to methods and apparatus for retubing of a nuclear reactor.
100031 More specifically, the invention relates to methods and apparatus for handling materials for retubing of a nuclear reactor such as a CANDUTm-type nuclear reactor. The CAN DUTm ("CANada Deuterium Uranium") reactor is a pressurized heavy-water moderated, fission reactor capable of using fuels composed of natural uranium, other low-enrichment uranium, recycled uranium, mixed oxides, fissile and fertile actinides, and combinations thereof.
SUMMARY
[0004] In one embodiment, the invention provides a method of calandria tube volume reduction during calandria tube replacement. The method includes the steps of removing at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring from a nuclear reactor at the reactor face; placing the at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring into a flask at the reactor face; transporting the flask away from the reactor;
removing the at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring from the flask; and performing volume reduction on the at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring.
[00051 In another embodiment the invention provides method of calandria tube volume reduction during calandria tube replacement. The method includes the steps of removing at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring from a nuclear reactor at the reactor face; placing the at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring into a flask at the reactor face; transporting the flask outside a vault containing the reactor; removing the at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring from the flask; and performing volume reduction on the at least one of an end fitting, a pressure tube, a calandria tube, and a garter spring.
100061 In another embodiment the invention provides a material handling system for use during retching of a nuclear reactor. The material handling system includes a track system including a plurality of track sections, wherein the track sections include at least one curved track section. The system also includes a trolley having a cargo bed, at least two wheel trucks operatively coupled to the cargo bed, and a guide mechanism for interacting with the track system, wherein at least one of the wheel trucks pivots relative to the cargo bed.
BRIEF DESCRIPTION OF THE DRAWINGS
100071 Various aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
[0008] Figure 1 shows the general flow of a full End Fitting (EF) flask from a platform tooling.
100091 Figure 2 shows the general flow of an empty fa: flask to the platform tooling.
[00101 Figure 3 shows an embodiment of a trolley.
[00111 Figure 4 shows an embodiment of a trolley with a l'T-CT-GS flask.
100121 Figure 5 shows an embodiment of a trolley with an EF flask.
[00131 Figure 6 shows an embodiment of a straight rail and sole plate section.
100141 Figure 7 shows an embodiment of a rail and sole plate layout in the reactor building.
100151 Figure 8 shows an embodiment of a trolley side shift assembly.
100161 Figure 9 shows the complete track system and identifies the section that is shown in detail in Figures 10A and 10B.

2 [0017] Figure 10A shows a trolley side shift assembly connecting a first trolley track.
[0018] Figure 10B shows the trolley side shift assembly connecting a second trolley track.
[0019] Figure 11 shows an embodiment of a truck gantry.
[0020] Figure 12 shows an embodiment of a buffer nest.
[0021] Figure 13 shows an embodiment of a buffer nest with two EF flasks.
[0022] Figure 14 shows an embodiment of a buffer nest with one PT-CT-GS
flask.
[0023] Figure .15 shows an embodiment of a flatbed nest.
[0024] Figure 16 shows an embodiment of a two flatbed nests on flatbed trailer holding two El; flasks each.
[0025] Figure 17 shows an embodiment of a two flatbed nests on flatbed trailer with one PT-CT-GS flask each.
[0026] Figure 18 shows an embodiment of a flatbed trailer schematic.
[0027] Figure 19 shows an embodiment of a flatbed trailer with tooling mounted thereon.
[0028] Figure 20 shows an embodiment of a building extension (box shown in bottom center of drawing).
100291 .Figure 21 shows a material handling tooling layout for an EF flask.
[00301 Figure 22 shows an embodiment of a shuttle flask.
[0031] Figure 23 shows an embodiment of an end fitting shield plug removal tool with a shuttle flask attached thereto.
[0032] Figure 24 shows an embodiment of Er: Pulled into EF flask.
100331 'Figure 25 shows an embodiment of EF Removal Tooling Retracted and El? in EF
flask.

3 [00341 Figure 26 shows an embodiment of Removal of a Full EF flask from the Platform Tooling.
100351 Figure 27 shows an embodiment of Installation of an Empty EF flask to the Platform 100361 Figure 28 shows an embodiment of a layout of an EF removal tool set.
100371 Figure 29 shows an embodiment of a Removal of a full CT-PT-GS flask from the platform Receive tooling.
[00381 Figure 30 Shows an embodiment of an Installation of an empty CT-PT-GS flask to the platform receive tooling.
100391 Figure 31 shows an embodiment of a CT-PI-GS flask.

[00411 Figure 32 is a perspective view of a reactor core of a nuclear reactor.
100421 Figure 33 is a cut-away view of the fuel channel assembly.
DETAILED DESCRIPTION
[00431 Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement a components set forth in the following description or illustrated in the Ibilowing drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
100441 The following is a description of one or more embodiments of methods and apparatus for handling materials for retubing of a nuclear reactor such as a CANDUrm reactor.
100451 Figure 32 is a perspective of a reactor core of a nuclear reactor 6.
The reactor core is typically contained within a vault that is sealed with an air lock 'for radiation control and shielding. A generally cylindrical vessel, known as a caland.ria 10, contains a heavy-water

4 moderator. The calandria 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 bores that accept a fuel channel assembly 28. As shown in Figure 32, a number of fuel channel assemblies 28 pass through the tube sheets 18 of calandria 10 from the first end 22 to the second end 24.
[00461 Figure 33 is a cut-away view of the fuel channel assembly 28. As illustrated in Figure 33, each fuel channel assembly 28 is surrounded by a calandria tube ("Cr') 32. The CT
32 forms a first boundary between the heavy water moderator of the calandria 10 and the fuel bundles or assemblies 40. The CTs 32 are positioned in the bores on the tube sheet 18. A CT
rolled joint insert 34 within each bore is used to secure the CT 32 to the tube sheet 18.
(0047) 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 the fuel bundles or assemblies 40. The PT 36, 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 the PT 36 and the CT 32. The annulus space 44 is normally filled with a circulating gas, such as dry carbon dioxide, helium, nitrogen, air, or mixtures thereof.
The annulus space 44 and gas are part of an annulus gas system. The annulus gas system has two primary functions.
First, a gas boundary between the CT 32 and PT 36 provides thermal insulation between hot reactor coolant and fuel within the PTs 36 and the relatively cool CTs 32.
Second, the annulus gas system provides an indication of a leaking CT 32 or PT 36 via the presence of moisture, deuterium, or both in the annulus gas.
[00481 An annulus spacer or garter spring 48 is disposed between the CT 32 and PT 36. The annulus spacer 48 maintains the gap between the PT 36 and the corresponding CT
32, while allowing the passage of the annulus gas through and around the annulus spacer 48. Maintaining the gap helps ensure safe and efficient long-term operation of the reactor 6.
[00491 As also shown in Figure 33, an end fitting 50 is attached around the fuel channel assembly 28 outside of the tube sheet 18 at each end 22, 24. At the front of each end fitting 50 is a closure plug 52. Each end fitting 50 also includes a feeder assembly 54. The feeder assemblies 54 feed reactor coolant into or remove reactor coolant from the PIs 36. 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 Figure 33, the feeder assemblies 54 can be attached to the end fitting 50 using a coupling assembly 56 including a number of screws, washers, seals, and/or other types of connectors.
109501 Coolant from the inlet feeder assembly flows along a perimeter channel of the end fitting 50 until it reaches a shield plug 58. The shield plug 58 is contained inside the end fitting 50 and provides radiation shielding. The shield plug 58 also includes a number of openings that allow the coolant provided by the inlet feeder assembly to enter an end of a PT 36. A shield plug 58 located within the end fitting 50 at the other end of the fuel channel assembly 28 includes similar openings that allow coolant passing through the PT 36 to exit the PT
36 and flow to the outlet feeder assembly 54 through a perimeter channel of another end fitting 50 at the opposite face of the reactor 6. As shown in Figure 32, feeder tubes 59 are connected to the feeder assemblies 54 that carry coolant to or away from the reactor 6.
100511 Returning to Figure 33, a positioning hardware assembly 60 and bellows 62 are also coupled to each end fitting 50. The bellows 62 allows the fuel channel assemblies 28 to move axially. The positioning hardware assemblies 60 are used to set an end of a fuel channel assembly 28 in either a locked or unlocked position. In a locked position, the end of the fuel channel assembly 28 is held stationary. In an unlocked position, the end of the fuel channel assembly 28 is allowed to move. A tool can be used with the positioning hardware assemblies 60 to switch the position of a particular fuel channel assembly 28.
100521 The positioning hardware assemblies 60 are also coupled to an end shield 64. The end shields 64 provide additional radiation shielding. Positioned between the tube sheet 18 and the end shield 64 is a lattice sleeve or tube 65. The lattice tube 65 encases the connection between the end fitting 50 and the PT 36 containing the fuel assemblies 40.
Shielding ball bearings 66 and cooling water surround the exterior the lattice tubes 65, which provides additional radiation shielding.
100531 Material handling refers to tooling whose primary function is to move and manipulate shielded flasks containing radioactive materials that are being removed from the reactor and transported to the waste processing facility. The secondary function of the material handling tooling is to assist in the movement of face tooling and materials during retube operations.
[0054] Material handling tooling consists of a system of trolleys, rails, rail switching equipment, nests and cranes used to manipulate and transport =flasks and other equipment to and from the opposing faces of the reactor. The tooling is designed to be used in conjunction with the reactor area (RA) cranes.
[0055] The material handling equipment is in "production" operation during three series: the End Fitting (EF) Removal series, the calandria Tube Insert (CT I) Removal series, and the Pressure Tube-calandria Tube-Garter Spring (PT-CT-GS) Removal series. The material handling method is the same whether the PT and CT are removed together or separately.
[00561 Material handling tooling is installed prior to the EF Removal series (during the PT
and Bellows Cut series) and removed after completion of the PT-CT-GS Removal series. The exception is the truck gantry which will be installed at the beginning of the retube outage and continue to function for the duration of the outage..
[00571 There are eight major components to the material handling system 1:
a trolley .200, trolley rails 216 and sole plates 234, a trolley side shift assembly 244, a truck gantry 260, a buffer nest 262, a flatbed nest 264, a flatbed trailer 274, and a weather enclosure 286.
100581 Figure 1 Shows steps 1-4 (below) of the general procedure at the reactor 6 for all three removal series. Figure 2 shows the reverse process (labelled below as steps 6-8 and annotated on Figure. 4 with reference numerals 105-108) for returning an empty flask 202, 204, 206 .from the truck to the face of the reactor 6. In general, the procedure includes: (1) At reference numeral 101, an empty flask 202, 204, 206 is mounted on the removal tooling 290 at the face of the reactor 6. The EP flasks .204 will need to reach both vaults 4, whereas the longer PT/CT flask .202 only needs to reach the nearer vault 4. (2) At reference numeral 102, the empty flask 202, 204, 206 is filled with radioactive materials from the removal series. This now becomes a full flask 202, 204, 206. (3) M reference numeral 103, the full flask 202, 204, 206 is unloaded from the removal tooling 290 to the trolley 200 using the RA crane. The fuel channel platform (FCP) (or retube platform, RTP) 292 may be positioned at floor level to facilitate and simplify flask movements. (4) At reference numeral 104, the full flask 202, 204, 206 is taken out of the reactor vault 4 to the truck loading area 248 via trolley 200. (5) At reference numeral 102, -using the truck gantry 260, the full flask 202, 204, 206 is removed from the trolley 200 and loaded onto the first buffer nest 262. (6) At reference numeral 106, an empty flask 202, 204, 206 is removed from the second buffer nest 262 and placed on the trolley 200 using the truck gantry 260. (7) At reference numeral 107, the trolley 200 moves from the truck loading area 248 to the reactor face with the empty flask 202, 204, 206. (8) At reference numeral 108, the cycle starts again from Step I (i.e. reference numeral 101).
100591 Radioactive material is contained within the shielded flasks 202, 204, 206 at all times when removed from the reactor face.
100601 While the removal operations are occurring on the reactor face, and while the trolley 200 is moving back and forth from the reactor 6 and the truck loading area 248, the operators in the truck loading area 248 will be working in parallel. Empty flasks 202, 204, 206 arriving on the truck will he moved to the first buffer nest 262 in advance. When full flasks 202, 204, 206 arrive on the trolley 200, they will be unloaded to the second buffer nests 262 instead of being loaded directly to the truck. The buffer nests 262 are much closer to the trolley stop position and this minimizes the time to exchange full flasks 202, 204, 206 for empty ones.
This in turn minimizes the waiting time at the face for empty flasks 202, 204, 206 to arrive.
100611 In general, the procedure at the truck loading area 248 includes:
(1) A truck from the processing facility containing empty flasks 202, 204, 206 will enter the truck loading area 248 in the reactor 6 and park. (2) The doors on the weather enclosure 286 will be closed so that the entire truck is protected from the elements. The cover 280 for the flatbed 274 will be rolled back and the empty flasks 202, 204, 206 on the flatbed nests 264 will be unsecured for hoisting. (3) Using the truck gantry 260, an empty flask 202, 204, 206 will be hoisted and moved from the flatbed nest 264 to the first buffer nest 262. For C'I'l and Er; flasks 204, two flasks can be placed in a single buffer nest 262. (4) A trolley 200 with a MI flask 202, 204, 206 from the reactor 6 arrives in the truck loading area 248. (5) The full flask 202, 204, 206 on the trolley 200 will be loaded onto the second buffer nest 262. (6) The empty flask 202, 204, 206 will be loaded from the first buffer nest 262 onto the trolley 200 and sent back to the reactor 6.
(7) The full flask 202, 204, 206 on the second buffer nest 262 will be loaded and secured onto the flatbed nest 264.
(8) Repeat Steps 3 to 7 until there are no more empty flasks 202, 204, 206.
(9) When the flatbed nest 264 is full of full flasks202, 204, 206, the cover 280 on the flatbed 274 will be closed and the truck will leave for the processing plant. (10) The truck arrives at the processing plant and the ftill flasks 202, 204, 206 will be removed and empty flasks 202, 204, 206 will be loaded.
(11) The truck returns to the reactor 6 with empty flasks 202, 204, 206. (12) Repeat from Step 1.
100621 in some embodiments, there are at least two trucks running in parallel at all times in order to minimize flask wait times.
100631 At all times, exchanging flasks 202, 204, 206 on incoming trolleys 200 will be the highest priority. To this effect, hoisting operations to load or unload the truck may not be as efficient in order to keep operations at the reactor 6 moving as quickly as possible. Additionally, the buffer nests 262 in the truck loading area 248 allow hoisting operations to be flexible.
Hoisting can continue while trolleys 200 are moving through the vault 4 or while operations happen on face.
100641 Figures 3, 4, and 5 illustrate trolleys 200 that are used to convey flasks 202, 204, 206, tooling and other materials from one end of both faces of the reactor 6 to the truck loading area.
Flasks 202, 204, 206 and other loads are lowered onto the bed of the trolleys 200. Each trolley 200 has locating and positioning features to prevent loads from moving once placed on the trolley 200 (e.g. nests 208 for stabilizing loads as shown in Figures 3,4, 5, and 12-14). The trolleys 200 also include a guide mechanism 210 for interacting with the track system 212, where the guide mechanism 210 may include flanged wheels 214 that rest on parallel rails 216.
Alternatively, the guide mechanism 210 may include a carriage attached to the trolley 200, where the carriage is in contact with a rail to guide the trolley.
100651 In one embodiment, trolleys 200 move on flanged wheels 214 captured on tracks similar to railroad tracks. In various embodiments, the trolleys have two pivoting axles to allow tight turns to be made on curved tracks. In other embodiments, the wheels of the trolley are not be flanged and instead the trolleys have wheels (e.g. castered wheels) that run on the floor of the building. The non-flanged wheels may roll directly on the floor of the building or on plates or other surfaces provided (e.g. to provide a smooth and level surface).

100661 In various embodiments, the trolleys 200 are powered by electric motors 224 (e.g.
mounted adjacent to wheel trucks 230 under the trolley 200 as shown in Figure 3), which may be manually controlled by an operator holding a pendant with a deadrnan trigger.
In general, trolleys 200 are equipped with brakes which automatically engage when not in motion to act as a parking brake, as well as an emergency brake when releasing the deadman trigger on the pendant. The bed 228 of each trolley is quickly configurable with nests 208 for carrying flasks 202, 204,206, tools or other miscellaneous loads. In various embodiments, a standard trolley design will be used to carry all materials. Each trolley 200 has a cargo bed 228 and at least two wheel trucks 230 (e.g. see Figure 3), where at least one of the wheel trucks 230 pivots relative to the cargo bed 228 in order to permit the trolley 200 to move on curved track portions.
[00671 Under normal operation, one trolley 200 is allocated for transferring all flasks 202, 204, 206 from one face of the reactor 6 and one trolley 200 will be allocated for transferring all the flasks 202, 204, 206 from the other face of the reactor 6. Details of the trolley operations and movements are found in the individual removal sections.
100681 In various embodiments, trolleys 200 are capable of towing/pushing other trolleys 200 in case of motor failure. The trolleys 200 also have the capability of being winched along the tracks in case of manual contingency operation.
[00691 In various embodiments, a track system 212 (e.g. sec Figure 1) including a plurality of track sections 232 is installed in the reactor building 2. As discussed below, the plurality of track sections 232 may include curved sections 232B to allow the track system to be installed without having to remove existing reactor structures.
100701 In some embodiments, trolleys 200 move on rails 216 similar to railroad tracks. In those embodiments in which a rail or rails 216 are employed (e.g. a pair of rails for use with -flanged wheels or a single rail or multiple rails used to guide eastered wheels as described above), the rail or rails 216 may be mounted to a large sole plate 234 which includes a track section sub-assembly. In addition to straight sections 232A (shown in Figure 6), curved sections 23213 of track have been incorporated as well in order to avoid removing existing reactor structures. In general, where two (or more) rails 216 are used to accommodate flanged wheels .õ CA 3028463 2018-12-21 214 or .to guide a carriage attached to the trolley 200, the rails 216 are installed parallel to one another at a fixed distance apart.
10071.1 Each sole plate 234 will be equipped with quick jacking mechanisms for levelling as well as quick -floor lagging provisions. This combined with the rails 216 preassembled onto the sole plates 234 will allow for maximum efficiency and ease of installation.
Each of these track sections 232 will be fully connected and tested prior to installation in the reactor 6, resulting in a minimum of on-site set up and adjustment. The vault floor will require inserts placed into the floor in advance of installation of the sole plates 234.
100721 Sole plates 234 in the airlock 246 will not be lagged inside the airlock area but clamped just outside of the airlock envelope. The clamping allows for quick removal of the sole plates 234 in the airlock 246 in the event the airlock 246 needs to be closed.
[00731 As shovvn in Figure 7, there is one main line 240 which stretches from one face of the reactor 6 through the airlock 246 and out into the truck loading area 248.
This main line 240 contains docking stations at the trolley side shift assembly 244 and at the end of the rail in the truck Loading area 248.
100741 A secondary line 242 stretches through a side of the vault 4 through the walkway.
The trolley 200, EP flasks 204, and CTI flasks (not shown) are small enough in diameter to -fit within the side doorways with clearance.
100751 The trolley side shift assembly 244 (Figure 8) is a track switching mechanism used to connect trolleys 200 from either face of the reactor 6 to the main line 240.
Additionally, due to the tight space constraints with the long PT-CT-GS flask 202, the direct, linear motion of the side shift is required to bring the flask 202 within the envelope of the RA crane.
In general the side shift assembly 244 is mounted near the reactor 6 to permit ACC= to both faces of the reactor 6 and to permit a trolley 200 on one track section to be loaded and unloaded while another trolley 200 moves past to the other side of the reactor 6 (e.g. Figure 1).
[00761 This mechanism consists of a large slide plate 252 with two sets of trolley rails 216 mounted on it. The first set of rails 216 is straight and the second set of rails 216 is curved to provide a larger turning radius for the trolleys 200 operating from one of the reactor faces. The slide plate 252 is mounted on precision linear bearings (not shown) and rails 254 and is driven by a ball screw powered by a motor 258. The slide plate 252 will move and align either the first trolley track or the second trolley track with the main line 240 out of the airlock 246 (see Figure 8).
[0077] When the trolley 200 associated with the second reactor face is aligned to the main line 240, the trolley 200 aligned with the first reactor face is within the corresponding RA crane reach envelope. This allows the trolley 200 associated with the first reactor face to be loaded or unloaded from the reactor face while the trolley 200 associated with the second reactor face passes through. When the trolley associated with the first reactor face is aligned to the main line 240 the trolley associated with the second reactor face must wait until the side shift is performed.
[0078] The trolley side shift assembly 244 is controlled by an operator using a simple pendant with a deadman trigger. The side shift movement 244 will only continue while the operator presses the deadman trigger. The ball screw drive motor 258 is equipped with a brake which automatically engages when not in motion to act as a parking brake as well as an emergency brake when releasing the deadman trigger on the pendant. The trolley side shift assembly 244 is designed to be brought into the vault 4 as a single piece and installed as a complete turnkey sub-assembly.
100791 The truck gantry 260 (Figure 11) is a new installation to be erected in the area just outside of the shielding door of the airlock 246. This is the main gantry used in loading and unloading all trucks coming in the docking bay 248 of the reactor building 2.
Due to the close proximity to the vault airlock 246, the docking bay 248 will handle the majority of tools and materials used for the duration of the retube operations.
[00801 The gantry 260 is included in the Material Handling section of this proposal but will be installed at the beginning of the retube outage and used throughout the entire retube operation as the main truck load/unload crane.
[0081] The main function of the gantry 260 during the removal series is to load and unload flasks 202, 204, 206 from the trolleys 200, buffer nests 262 and the flatbed nest 264. In addition, the gantry 260 will be used to place and remove trolleys 200 onto the tracks 212 as well as materials and tooling used on face during the removal series.
[00821 This gantry 260 is a custom frame gantry which will have travel in two axis as well as the hoist. The gantry 260 will be made modular and designed for quick assembly without the use of heavy machinery. The gantry 260 is fully certified as an overhead lifting device.
100831 Lag studs will have to be pre-installed into the floor in the truck loading area 248 prior to the gantry 260 being brought on site.
100841 The buffer nest 262 (Figure 12) is a static cradle designed to hold a single CT-PT-OS
flask 202 (Figure 14) or two FF flasks 204 (Figure 13). The buffer nest 262 provides a place to temporarily place a flask 202 204, 206 so a trolley 200 or the flatbed nest 264 can be cleared.
[00851 The buffer nests 262 arc heavy duty weldments which contain rough positioning features 268 used to place the different flasks 202, 204, 206 in repeatable locations. The positioning features 268 have much greater clearances than those used on the trolleys 200 or tools to allow for quick placement and pick up of flasks 202, 204, 206. The buffer nests 262 will require lagging to the ground to prevent accidental movement. In some embodiments, there are two buffer nests 262 positioned close to the trolley docking position in the truck loading area 248.
[00861 Lag studs will need to be pre-installed into the floor in the truck loading area 248 prior to the buffer nests 262 being brought on site.
100871 The flatbed nest 264 (Figure 15) provides a fiarne in which to secure flasks 202, 204, 206 for transport via truck. The flatbed nest 264 is bolted to the bed of the flatbed trailer 274 and will remain in place for the duration of the removal series. The flatbed nest 264 is designed to hold one CT-PT-US flask 202 (Figure 16) or two EF flasks 204 (Figure 17) each.
Two flatbed nests 264 can be mounted in a single flatbed trailer 274.
100881 Similar to the buffer nest 262, the flatbed nest 264 is a heavy duty weldment which contains positioning features 276 used to place the different flasks 202, 204, 206 in repeatable locations. The positioning features 276 are similar to those used on the trolleys 200 or removal tools to prevent movement of flasks 202, 204, 206 during truck transport. The flatbed nest 264 also contains a quick chain winch tie-down system which will be integrated into the flask design.
All tic-downs will be manually actuated. These will be custom tailored to the flasks 202, 204, 206 so that securing and releasing the flasks 202, 204, 206 from the nests 264 will take a minimum of time and effort.
100891 The nests 264 need to be installed into the flatbed trailers 274 prior to the beginning.
of the removal series.
100901 The flatbed trailer 274 (Figure 18) is used to transport 'flasks 202, 204, 206 between the reactor building (R.1.1) 2 and the processing plant. The flatbed trailer 274 is a drop deck roll-tight trailer which is custom-modified to carry extremely heavy loads. The trailer 274 has a roll-tight cover 280 which is a retractable fabric and metal frame bellows cover.
The cover 280 can quickly be rolled over the bed 282 of the trailer 274 providing a weatherproof enclosure around the load during transport. It can then be unrolled to provide full top and side access to the load.
An embodiment of the flatbed trailer 274 is shown in Figure 19.
100911 In other embodiments, provisions are made for mounting the flatbed nest weldm.ents, such that the flatbed trailer 274 will hold a pair of flatbed nests 264.
100921 In some embodiments, trucks backing into the RB 2 outside of the truck loading door 284 cannot now drive fully inside the existing reactor 6 due to unloading clearance requirements.
This means that the loading door 284 would remain open to the elements for extended periods.
To prevent this scenario, a weather enclosure 286, or building extension (Figure 20), to the truck docking area 248 will be constructed so the entire truck can be housed inside an enclosure and the RB 2 can be isolated from the elements. This construction will include any reinforcement of the ground outside and inside the building loading dock 248, as well as guides and bumpers to facilitate the quick entry and exit of the trucks.
100931 In some embodiments, an electric winch is used to move trolleys 200 or to actuate the trolley side shift assembly 244 in case of motor or ball screw failure.
Regular mounting points along the track 212 or trolley side shift assembly 244 will be provided to connect the winch.

[00941 In some embodiments, a ratcheting come-along is used to move trolleys 200 or to actuate the trolley side shift assembly 244 in case of complete power failure.
Mounting points along the track 212 or trolley side shift assembly 244 will be provided to connect the come-along.
[00951 Figure 21 shows the rail layout from a plan view of the R13 2. In the illustrated embodiment, the rail layout includes a main line 240 (through airlock 246), a secondary line 242 (through a vault corridor), a trolley side shift assembly 244 , an airlock 246 , a truck loading area 248 , a truck gantry 260 , a buffer nest 262 , a flatbed nest 264, a flatbed trailer 274 , and a weather enclosure 286.
[0096] The material handling system 1 and flasks 204 can be used in the end fitting removal series, as described below. In this series all EFs 50 are removed from the reactor 6. The El:
removal tooling 290 on the platforms 292 are identical. The EFs 50 are removed simultaneously in a staggered fashion from both reactor faces to accommodate EF flask trolley vault traffic.
[00971 A single channel cycle involves removing an EX 50 from a lattice site and placing it into a shielded flask 204, inserting a lattice sleeve assembly 65 (LSA), removing the full flask 204 from the vault 4, and installing an empty flask 204 back onto the removal tooling 290. The cycle can begin by starting at the bottom row and working up the reactor face.
In parallel, the lid! flask 204 is being delivered to a volume reduction facility. In various embodiments, the volume reduction facility is located away from the reactor face, which may still be within the reactor vault 4 or which may be outside of the building 2 containing the reactor 6. There the flask 204 is emptied and returned in queue for reinstallation on the removal tooling 290.
100981 In one embodhnent, the PT 36, CT 32, and GS 48 arc placed in the flask 202, which is then rotated on the platform 292. The platform 292 is subsequently lowered to floor elevation.
The volume reduction equipment is stationed on the floor beside the platform 292. The contents of the flask 202 arc pushed into the volume reduction machine and volume-reduced components fall into a flask that sits beneath the volume reduction machine. In general, the flask on the platform for the FT/CT/GS remains on the platform for the duration of the removal sequence, whereas the flask beneath the volume reduction machine is replaced when full.

100991 The EF Removal Series can be divided into automated and manual operations. The automated operations may be controlled remotely from the retube control center (RCC) or locally from pendants and are those associated with the face operation with the tools on the heavy work table 300 (HWT). This is for ALAR.A. (as low as reasonably achievable) purposes, so that people may be kept away from the highly radioactive operations as much as possible.
The manual operations are those associated with the hoisting and transportation of flasks 202, 204, 206 and lattice sleeves 65.
1001001 The layout of the tools on the RTP 292 is shown in Figure 28. These tools include an 11.-WT 300 , a pallet 302 , a lattice tube shield plug insert removal tool (Ls-svrico 304 , an EF
flask 204 , an BF retrieval head 306 , and El: shield 308 , an LSA 310 , and a vision system 312.
In various embodiments, these tools may be moved by the vault trolley system 201 and hoisted by the RA crane for vault transitions.
[001011 The process for removing an Eh' 50 from a lattice site and placing it into an EF flask 204 is as follows. Not all of the listed steps are required; for example, steps (8) and (9) may be omitted. In various embodiments, all of the operations are carried out using automated tooling.
(1) Prerequisites include: (a) The EF flask 204 is mounted to the pallet 302, and a LSA 310 is mounted to the .EF flask 204; and (b) The RTP 292 is at the designated raw.
(2) The HINT 300 moves to bring the vision system 312 in front of the designated EF 50. (3) The vision system 312 calculates the offsets for fme alignment and then the HWT 300 moves to align the EF removal tooling 290 to the EF 50. (4) The pallet z-drive advances the EF shield 308 over the EF 50, and the pallet's Serapid drive advances the EF Retrieval Head 306 into the EF 50.

(5) The EF
retrieval head 306 grips the EF 50. (6) The pallet's Serapid drive pulls the EF 50 into the flask 204 (Figure 24). (7) The pallet z-drive retracts the EF Shield 308 from the El? 50, the EF
Retrieval Head 306 un-grips the EF 50, and the pallet's z-drive retracts the head 306 out of the EF flask 204 back into the guide tube 314. (Figure 25). (8) The HWT 300 indexes in the x-direction to align the vision system 312 to the open channel. (9) The vision system 312 shoots the outboard journal ring and CTI to establish the x-, y-, pitch-, and yaw-coordinates for the lattice site. These values are stored for use by all other automated series that follow. The vision system 312 does not have to be shot again unless there are problems with the tool accessing the site because of alignment issues. (10) The IIWT 300 indexes in the x-direction to align the axis of the LS SPIRT 304 with the lattice site. (11) The LS SPIRT 304 advances to install the LSA
310 into .the lattice site. (12) The 1,S SPIRT 304 retracts fully.
1001021 Replacement of a full BF flask 204 with an empty EL: flask 204 at the platform.
tooling is a manual process that requires the use of the vault RA cranes, vault trolley system 201, and truck loading facility. The removal of the full EF flask 204 from one side is Shown in Figure 26, and the installation of the empty EF flask 204 to the side is shown in Figure 27.
[001031 Before beginning the procedure, one empty trolley 200 is waiting to be loaded on the side shill: mechanism 244 and the RTP 292 is Wiped at the designated row. In various embodiments, the procedure for a flask replacement can include some or all of the following steps: (1) The platform 292 is lowered to the floor, and the IIWT 300 moves to a predetermined location. (2) Personnel enter the platform 292. (3) The shielded doors on the full EF flask 204 are closed and the .LSA supports are folded in. (4) The crane is positioned over the full EF flask 204. (5) The crane hook and guide cables are installed on the full EP flask 204. (6) The RA
crane and guide cables are used to hoist the full EF flask 204 to another section of the R.TP 292.
The full .EF flask 204 is rotated while hung on the crane to achi.eve the correct orientation to be placed on the trolley (Step 1 at reference numeral 110 in Figure 26). (7) The MI EF flask 204 is lowered onto the trolley 200 and the RA crane and cable guides are disconnected. (8) The trolley 200 with the full EF flask 204 is side shifted using the trolley side shift assembly 244. The trolley 200 now lines up with the tracks 240 exiting out the airlock 246 (Step 2 at reference ntuneral 112 in Figure 26). (9) The trolley 200 is driven through the airlock 246 to the truck loading area 248 (Step 3 at reference numeral 114 in Figure 26). (10) The truck gantry 260 and cable guides are connected to the full EF flask 204. The full 'U. flask 204 is hoisted and moved to a second buffer nest 262. The gantry 260 and cable guides are disconnected (Step 4 at reference numeral 116 in Figure 26). (11) The truck gantry 260 and cable guides are connected to the empty EF flask 204 in a first buffer nest 262. The empty EF flask 204 is hoisted and moved to the trolley 200. Th.e gantry 260 and cable guides are disconnected (Step I at reference numeral 118 in Figure 27). (12) The trolley 200 with the empty EF flask 204 is driven through the airlock 246 to the trolley side shift assembly 244 at the reactor face (Step 2 at reference numeral 120 in Figure 27). (13) The trolley with the empty EF flask 204 is side shifted so it is within the RA crane envelope (Step 3 at reference numeral 122 in Figure 27).
(14) The LSA

310 supports arc extended and the LSA 310 is manually loaded onto the EF flask 204 using the LSA loading mechanism (in other embodiments the LSA 310 is mounted to the flask 204 in an earlier step). (15) The RA crane and cable guides arc connected to the empty .EF flask 204. (16) The EF shield 308 should be in its forward position to provide clearance for the EF flask 204.
(17) An empty EF flask 204 is loaded on the pallet 302 (step 4 at reference numeral 124 in figure 27). (18) The operator manually retracts the EF Shield 308 and couples it to the EF flask 204. (19) All operators leave the RTP 292, and the platform 292 is raised from floor level to the designated row.
1091041 The procedure for replacing an EF flask 204 on the other side of the reactor 6 is very similar to the side discussed above. Trolleys coming and going to the other side will not need to be side shifted and pass directly through on the curved track section 23213 of the trolley side shift mechanism 244. EF flasks 204 from the other face will travel on a secondary line 242 which is laid in another area of the vault 4. This secondary line 242 is connected to the main line 240 out of the airlock 246 at the trolley side shift assembly 244.
[001051 Additional work is performed in the truck loading area 248 to prepare and clear flasks 202, 204, 206 from the buffer nests 262 and the truck. These processes are performed in parallel with work on the face and during trolley movement on the track 211 Operations in the truck loading area 248 are described elsewhere in this document.
[001061 Replacement of a full CT-PT-GS flask 202 with an empty CT-PT-OS flask 202 at one platform receive tooling is a manual process that requires the use of the vault crane, vault trolley System 201, and truck loading facility. The removal of the full CT-PT-GS flask 202 is shown in Figure 29, and the installation of the empty CT-PT-GS flask 202 is shown in Figure 30. The process is as follows: (1) One empty trolley 200 is -waiting to be loaded on the side shift mechanism 244, and the RTP 292 start at the designated row, and no workers are on the RTP 292 (Step I at reference numeral 126 in Figure 29). (2) The platform with the Guide Tooling remains at its current location. The other platform is lowered to the floor, and the I-1WT 300 moves to a predetermined location. (3) The shielded doors on the full CT-PT-GS flask 202 are closed. (4) The crane is positioned over the full CT-PT-OS flask 202 and the crane hook and guide cables are installed on the full CT-PT-GS flask 202. (5) The vault crane and guide cables are used to hoist the fall CT-PT-OS flask 202 to another section of the RTP 292 (Step 2 at reference numeral 128 in Figure 29). The full CT-PT-GS .flask 202 is rotated while on the crane to achieve the correct orientation to be placed on the trolley 200 (Step 3 at reference numeral 130 in Figure 29).

(6) The full CT-PT-GS flask 202 is lowered onto the trolley 200 and the vault crane and cable guides are disconnected (Step 4 at reference numeral 132 in Figure 29). (7) trolley side shift assembly 244 is used to line up the trolley 200 with the tracks 240 exiting out the airlock 246 (Step 5 at reference numeral 134 in Figure 29). (8) The trolley 200 is driven through the airlock 246 to truck loading area 248 (Step 6 at reference numeral 136 in Figure 29).
(9) Connect the truck gantry 260 and cable guides, lift the full CT-PT-GS flask 202 off trolley 200, rotate and hoist to a first buffer nest 262 (Step 7 at reference numeral 138 in Figure 29) and to a first flatbed nest 264 (Step 8 at reference numeral 140 in Figure 30). Disconnect the gantry 260 and cable guides. (10) Connect the truck gantry 260 and cable guides, lift the empty CT-PT-GS flask 202 frcan a second flatbed nest 264 and second buffer nest 262 (Steps 1 and 2 at reference numerals 142, 144 in Figure 30) , rotate and hoist to the trolley 200 (Step 3 at reference numeral 146 in Figure 30). (11) Disconnect the gantry crane and cable guides and drive the trolley 200 with the empty CT-PT-GS flask 202 to the reactor face (Step 4 at reference numeral 148 in Figure 30).
(12) Using the trolley side shift assembly 244, move the trolley 200 with the empty CT-PT-GS
flask 202 to within the vault crane envelope (Step 5 at reference numeral 150 in Figure 30). (13) Connect the vault crane and cable guides, hoist the empty CT-PT-GS flask 202 from trolley 200 to Tool. The CT-PT-GS flask 202 is rotated while on the crane to achieve the correct orientation to be placed on the tool (Steps 6-8 at reference numerals 152, 154, 156 in Figure 30). (14) The platform 292 is raised from floor level to the designated row, and the other platform is moved to the designated row if required.
1001071 A CT-PT-GS flask 202 is shown in Figure 31_ In various embodiments, the Functional requirements of the CT-PT-GS flask 202 are as follows: (1) Houses a single CT 32 and partial length PT 36, and four GSs 48. (2) Ends can be opened to permit loading and unloading operations, (3) ALARA shielding (including shielded body 316 and shielded door 318), permitting manual hoist and transport operations when the ends are closed. (4) The inner surfaces shall permit easy cleanup. (5) The outer surfaces shall decontaminate easily to permit transport. (6) As much as possible the design shall not allow radionuclides to fall out to the environment or contaminate the outside of the flask 202 when the ends are open during loading and unloading operations. (7) Contamination control to prevent the escape of radionuclides from the inside to the environment when the end have been closed, particularly during hoisting and transport operations. (8) Guidance for the Serapid chain ram and CT
Retrieval Head when they are advanced and retracted by the pallet 302. (9) Lilt points 320 lir hoisting and attachment points for guide cables. (10) Include a brake mechanism for the second pull with the CT
Retrieval Head. (11) Mount securely to the top of the pallet 302. (12) Allow transport via trolley system 201 in the vault 4 and truck to on-site volume reduction facility. (13) Interface with tooling at the volume reduction facility for unloading. (14) Designed for storage in type-A
container outside. (15) Function as an accessory to the pallet 302.
[00108] In various embodiments in which personnel are working with the CT-PT-GS flask 202, the shielding 316, 318 is designed for minimal radiation exposure to the personnel when the flask 202 is filled. Its features are designed with ALARA principles in mind, such that personnel minimize the amount of time they are in close proximity to the CT-PT-GS flask 202 during hoisting and transport activities. Manual operations on the CT-PT-GS
flask 202 include opening and closing the shielded doors 318, locking and unlocking the shielded doors 318, rigging fir hoisting, hoisting to and from the trolley system 201, pallet 302, and truck, and transport on the trolley system 201.
1001091 The Brackets 322 incorporate contact points that guide the CT-PT-GS
flask 202 into precise alignment on the pallet 302 during installation. The pallet 302 and CT-PT-GS flask 202 are designed with adequate clearances to allow for easy installation and removal of the CT-PT-GS flask 202.
1001101 The CT-PT-GS flask 202 includes features that function with the automated system.
These include an electromechanical brake mechanism on the body 316 of the flask 202 that engages with the CT Retrieval Head during the second pull, and sensors on the doors 318 to indicate if they are open or closed. These devices use a quick disconnect for installation and removal of the CT-PT-GS tlask 202.
1001111 In one embodiment, the body 316 is made from carbon steel and the ends 318 are made from lead. In other embodiments, the flask 202 comprises a lead-filled steel shell. It is designed to be maintenance free during a retube outage, and requires maintenance in between retube outages.
1001121 Remove End Fittings / SP & Flasking 1001131 After the pressure tubes 36 are cut the end fittings 50 are removed.
The inboard end of the end fitting 50 contains a portion of the pressure tube 36 from the pressure tube cutting operation, also the fuel channel shield plug 58 and liner tube are located in the end fitting 50 and positioned at their design location. Because these components are highly radioactive a shuttle flask 206 is used to provide the required shielding to reduce exposure to the worker. The shuttle flask 206 is lowered onto a trolley 200 and rail system 212 using a crane. The shuttle flask 206 is then transferred to the End Fitting Transfer Station (EFTS) located in the vault 4 where the EF
50 is transferred to a Large Waste Transfer Flask (LNTF).
1001141 In various embodiments, the shuttle flask 206 is lifted off the EFSP
removal tool 324 with the Fuel Machine Bridge crane, then the shuttle flask 206 is moved over the FCP hatch with the Fuel Machine carriage. This can be a bottle-neck due to the special care required to lift and move a 10 Ton weight across the platform 292 to the hatch with very slow speed. The process is optimized by moving the shuttle flask 206 over the hatch using the heavy work table 300. Once the flask 206 is lifted with the crane, the heavy work table 300 can be moved out of the way and the flask 206 lowered to the vault floor. This simple change can reduce complication and save time as the heavy work table 300 can transport the shuttle flask 206 with a higher speed and less risk. The operation involving a 10 Ton object moving across the platform 292 in mid air can thus be eliminated.
1001151 In those embodiments in which the End Fitting / SP Removal & Masking series is performed at a high production rate, the optimization of the processes and tools as outlined contribute to minimizing the amount of time required to complete the work, resulting in lower costs and lower radiation exposure to workers.
[001161 The primary function of the EFTS is to safely transfer the EF 50 from the shuttle flask 206 into the Large Waste Transfer Flask (WIT). At the reactor face, the EF 50 is removed from the lattice site and pulled into the shuttle flask 206 with the EFSP removal tool 324. The shuttle flask 206 is then lowered onto the shuttle flask trolley 200 located on the Fuelling Machine (FM) vault floor, using the FM bridge crane. The shuttle flask trolley 200 is used to transfer the shuttle flask 206 to the FM maintenance lock. Once in the maintenance lock, the shuttle flask 206 is lifted from the trolley 200 and lowered onto the EFTS using the FM Maintenance Lock crane.
One of the main components of the EFTS is the End Fitting Ram, which pushes the EF through Flask-to-Flask Interface (HI) into the LWTF. The FFI is an interface that connects the shuttle flask 206 and the LWTF that shields the operator from unnecessary radiation doses.
[00117] Remove Pressure Tubes & Flasking 100118] The main objective of the Pressure Tube Removal & Flasking series is to pull the pressure tube 36 from the fuel channel 28 and into a volume reduction machine that will cut the -pressure tube 36 into small pieces and place those pieces into an attached small waste transfer flask. Pressure tube removal series begins at the bottom row and works up to the next above row, from the lattice site near the middle of the ealandria 10 to the periphery channels. Each VRS removes approximately half of the pressure tubes 36.
1001191 In thc embodiment disclosed herein, the V RS is performed outside of the reactor vault 4 such that the crushing machines can be larger and the crushing process can be performed in . parallel, increasing the production rate. In those embodiments in which the Remove Pressure Tube series is performed at a high production rate, the optimization of the processes and tools as outlined contribute to minimizing the amount of time required to complete the work, resulting in lower costs and lower radiation exposure to workers.
1001201 Thus, the invention provides, among other things, methods and apparatus for handling materials for retubin.g of a nuclear reactor 6.

,t, CA 3028463 2018-12-21

Claims (16)

What is claimed is:

1. A material handling system for use during retubing of a CANDU reactor, comprising:
a track system comprising a plurality of track sections, wherein the track sections include at least one curved track section; and a trolley comprising a cargo bed, at least two wheel trucks operatively coupled to the cargo bed, and a guide mechanism for interacting with the track system, wherein at least one of the wheel trucks pivots relative to the cargo bed.

2. The material handling system of claim 1, wherein each of the plurality of track sections comprises at least two adjacent rails, wherein the guide mechanism of the trolley comprises flanged wheels attached to the at least two wheel trucks, and wherein the flanged wheels are spaced to align with the rails of the track sections.

3. The material handling system of claim 1, wherein each of the plurality of track sections comprises a rail, and wherein the guide mechanism of the trolley comprises a carriage in contact with the rail.

4 The material handling system of claim 1, further comprising a side-shift assembly to link two portions of the track system.

5. The material handling system of claim 4, wherein the side-shift assembly comprises two track sections on a moveable sole plate, at least one of the two track sections being a curved track section,

6. The material handling system of claim 5, wherein the side-shift assembly comprises a curved track section and a straight track section.

7. The material handling system of claim 4, wherein the side-shift assembly is near the reactor.

8. The material handling system of claim 1, wherein the wheel trucks each comprise a plurality of wheels and wherein the trolley further comprises a motor operatively coupled to the at least one of the wheels to propel the trolley.

9. The material handling system of claim 1, wherein the cargo bed of the trolley further comprises a removable cargo nest.

10. The material handling system of claim 1, wherein at least one track section is attached to a sole plate.

11. The material handling system of claim 10, wherein the sole plate comprises a jacking mechanism for leveling the sole plate.

12. The material handling system of claim 1 0, wherein the sole plate is coupled to a floor.

13. The material handling system of claim 1, further comprising a flask for holding an element of the reactor in substantially one piece.

14. The material handling system of claim 13, wherein the element of the reactor is an end fitting.

15. The material handling system of claim 13, wherein the element of the reactor is a pressure tube-calandria tube-garter spring assembly.

16. The material handling system of claim 13, wherein the flask comprises a metal tube having at least one removable end.