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Patent 2766575 Summary

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Claims and Abstract availability

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(12) Patent: (11) CA 2766575
(54) English Title: PALLET FOR NUCLEAR REACTOR RETUBE
(54) French Title: PALETTE POUR LE REMPLACEMENT DES TUBES D'UN REACTEUR NUCLEAIRE
Status: Granted
Bibliographic Data
(51) International Patent Classification (IPC):
  • G21C 17/017 (2006.01)
  • G21C 21/00 (2006.01)
(72) Inventors :
  • KING, JAMES MITCHELL (Canada)
  • COX, CLAIR ARTHUR (Canada)
  • WRAY, RICHARD WILFRID (Canada)
  • SCHAUBEL, TERRY JOHN (Canada)
  • POFF, DAVID ERIC (Canada)
(73) Owners :
  • ATOMIC ENERGY OF CANADA LIMITED (Canada)
(71) Applicants :
  • ATOMIC ENERGY OF CANADA LIMITED (Canada)
(74) Agent: NORTON ROSE FULBRIGHT CANADA LLP/S.E.N.C.R.L., S.R.L.
(74) Associate agent:
(45) Issued: 2018-03-13
(22) Filed Date: 2012-01-16
(41) Open to Public Inspection: 2012-07-14
Examination requested: 2016-10-20
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
61/432,981 United States of America 2011-01-14

Abstracts

English Abstract

A pallet for supporting one of a plurality of tools for a nuclear reactor retubing operation, the pallet positionable adjacent to an end-face of a nuclear reactor core having a plurality of fuel channel assemblies having longitudinal axes aligned substantially parallel to each other. The pallet includes an elongated frame extending generally parallel to the longitudinal axes of the fuel channel assemblies for supporting one of the tools for the nuclear reactor retubing operation, the frame having guide surfaces for aligning the tool parallel to the longitudinal axes of the fuel channel assemblies. The pallet also includes an electrical cable connectable to the tool and a hydraulic hose for providing a pressurized fluid to the tool. The pallet is configured to interchangeably accommodate another of the plurality of tools using the same elongated frame, electrical cable and hydraulic hose.


French Abstract

Une palette sert à supporter une pluralité des outils destinés à une opération de retubage de réacteur nucléaire, la palette pouvant être positionnée adjacente à une face dextrémité dun cur de réacteur nucléaire comportant une pluralité densembles de canaux de combustibles ayant des axes longitudinaux alignés substantiellement alignés parallèles entre eux. La palette comprend un cadre allongé se prolongeant généralement parallèle aux axes longitudinaux des ensembles de canaux de combustible servant à supporter un des outils destinés à lopération de retubage de réacteur nucléaire, le cadre comportant des surfaces guides servant à aligner loutil parallèle aux axes longitudinaux des ensembles de canaux de combustible. La palette comprend également un câble électrique raccordable à loutil et un tuyau hydraulique servant à fournir un fluide sous pression à loutil. La palette est configurée pour accommoder de manière interchangeable un autre de la pluralité doutils au moyen des mêmes cadre allongé, câble électrique et tuyau hydraulique.

Claims

Note: Claims are shown in the official language in which they were submitted.


What is claimed is:
1. A pallet for supporting one of a plurality of tools for a nuclear
reactor retubing operation,
the pallet positionable adjacent to an end-face of a nuclear reactor core
having a plurality of fuel
channel assemblies having longitudinal axes aligned substantially parallel to
each other, the
pallet comprising:
an elongated frame extending generally parallel to the longitudinal axes of
the fuel
channel assemblies for supporting one of the tools for the nuclear reactor
retubing operation, the
frame having guide surfaces for aligning the tool parallel to the longitudinal
axes of the fuel
channel assemblies; and
at least one of an electrical cable connectable to the tool and a hydraulic
hose for
providing a pressurized fluid to the tool;
wherein the pallet is configured to interchangeably accommodate another of the
plurality
of tools using the same elongated frame and the same electrical cable and/or
hydraulic hose.
2. The pallet of claim 1, further comprising a hydraulic assembly coupled
to the elongated
frame for supplying the pressurized fluid to the hydraulic hose.
3. The pallet of claim 2, further comprising an electrical panel coupled to
the elongated
frame for receiving the electrical cable.
4. The pallet of claim 1, further comprising a ram drive for pushing and
pulling the tool
towards and away from the end face of the nuclear reactor core in a direction
substantially
parallel to the longitudinal axes, the ram drive including a ram drive
connector for coupling to
the tool.
5. The pallet of claim 4, wherein the ram drive connector includes a quick
release pin and
bracket for coupling to the tool.
6. The pallet of claim 5, wherein the ram drive further comprises:
12

a push pull chain, the ram drive connector being coupled to a free end of the
push pull
chain; and
a drive assembly including a motor for driving the push pull chain towards and
away
from the end face of the nuclear reactor core.
7. The pallet of claim 4, wherein the ram drive further comprises:
a push pull chain; and
a drive assembly including a motor for driving the push pull chain towards and
away
from the end face of the nuclear reactor core;
wherein the electrical cable and the hydraulic hose are threaded alongside the
push pull
chain for movement with the push pull chain.
8. The pallet of claim 4, further comprising a control system for
controlling the ram drive to
move the tool towards and away from the end face of the nuclear reactor core.
9. The pallet of claim 1, further comprising a Z-axis drive for moving the
elongated frame
towards and away from the end face of the nuclear reactor core in a direction
substantially
parallel to the longitudinal axes.
10. The pallet of claim 1, wherein the electrical cable includes a sensor
cable.
11. The pallet of claim 1, wherein the pallet includes the electrical cable
and the hydraulic
hose.
12. The pallet of claim 1, further comprising a wireless system configured
to wirelessly
communicate at least one of a control signal and sensor data.
13

13. A pallet for supporting one of a plurality of tools for a nuclear
reactor retubing operation,
the pallet positionable adjacent to an end face of a nuclear reactor core
having a plurality of fuel
channel assemblies having longitudinal axes aligned substantially parallel to
each other, the
pallet comprising:
an elongated frame extending generally parallel to the longitudinal axes of
the fuel
channel assemblies for supporting one of the tools for the nuclear reactor
retubing operation, the
frame having guide surfaces for aligning the tool parallel to the longitudinal
axes of the fuel
channel assemblies; and
a ram drive for pushing and pulling the tool towards and away from the end
face of the
nuclear reactor core in a direction substantially parallel to the longitudinal
axes, the ram drive
including a ram drive connector for coupling to the tool;
wherein the pallet is configured to interchangeably accommodate another of the
plurality
of tools using the same elongated frame and ram drive connector.
14. The pallet of claim 13, wherein the ram drive connector includes a
quick release pin and
bracket for coupling to the tool.
15. The pallet of claim 14, wherein the ram drive further comprises:
a push pull chain, the connector coupled to a free end of the push pull chain;
and
a drive assembly including a motor for driving the push pull chain towards and
away
from the end face of the nuclear reactor core.
16. The pallet of claim 15, wherein the motor includes first and second
motors for
redundancy and wherein the drive assembly further comprises a 90 degree dual
input gear box
for converting rotational motion of a motor drive shaft into rotational motion
of a
perpendicularly aligned shaft for driving the push pull chain.
17. The pallet of claim 13, further comprising a control system for
controlling the ram drive
to move the tool towards and away from the end face of the nuclear reactor
core.
14

18. The pallet of claim 13, further comprising a Z-axis drive for moving
the elongated frame
towards and away from the end face of the nuclear reactor core in a direction
substantially
parallel to the longitudinal axes.
19. The pallet of claim 13, further comprising a wireless system configured
to wirelessly
communicate at least one of a control signal and sensor data.
20. A pallet for supporting one of a plurality of tools for a nuclear
reactor retubing operation,
the pallet positionable adjacent to an end face of a nuclear reactor core
having a plurality of fuel
channel assemblies having longitudinal axes aligned substantially parallel to
each other, the
pallet comprising:
an elongated frame extending generally parallel to the longitudinal axes of
the fuel
channel assemblies for supporting one of the tools for the nuclear reactor
retubing operation, the
frame having guide surfaces for aligning the tool parallel to the longitudinal
axes of the fuel
channel assemblies; and
a Z-axis drive for moving the elongated frame towards and away from the end
face of the
nuclear reactor core in a direction substantially parallel to the longitudinal
axes;
wherein the pallet is configured to interchangeably accommodate another of the
plurality
of tools using the same elongated frame.
21. The pallet of claim 20, wherein the Z-axis drive includes a lead screw
and guide system.
22. The pallet of claim 21, wherein the Z-axis drive further comprises a
first motor coupled
to a first end of the screw and a second motor coupled to a second end of the
screw, the first and
second motors providing redundancy for driving the lead screw and guide
system.
23. The pallet of claim 20, further comprising a local electrical panel for
interfacing to the Z-
axis drive.
24. The pallet of claim 20, further comprising a wireless system configured
to wirelessly
communicate at least one of a control signal and sensor data.

Description

Note: Descriptions are shown in the official language in which they were submitted.


CA 2766575 2017-02-27
Attorney Docket No. 027813-9035-CA00
PALLET FOR NUCLEAR REACTOR RETUBE
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional Patent
Application No.
61/432,981, filed January 14,2011.
BACKGROUND
[0002] The present invention relates to nuclear reactors. More
particularly, the invention
relates to equipment used in maintenance of nuclear reactors, such as for
retubing a nuclear
reactor. Typically, equipment for retubing operations is heavy and bulky. One
piece of
equipment includes a tool for performing one of the many functions performed
during the
retubing operation, as well as all of the electrical and hydraulic equipment
associated with that
tool. Each time a new function is performed, requiring a new tool, all of the
equipment for the
old tool must be uninstalled, and all of the equipment for the new tool must
be installed in its
place. This is time consuming and inefficient.
SUMMARY
[0003] In one embodiment, the invention provides a pallet for supporting
one of a plurality
of tools for a nuclear reactor retubing operation, the pallet positionable
adjacent to an end-face of
a nuclear reactor core having a plurality of fuel channel assemblies having
longitudinal axes
aligned substantially parallel to each other. The pallet includes an elongated
frame extending
generally parallel to the longitudinal axes of the fuel channel assemblies for
supporting one of
the tools for the nuclear reactor retubing operation, the frame having guide
surfaces for aligning
the tool parallel to the longitudinal axes of the fuel channel assemblies. The
pallet also includes
at least one of an electrical cable connectable to the tool and a hydraulic
hose for providing a
pressurized fluid to the tool. The pallet is configured to interchangeably
accommodate another
of the plurality of tools using the same elongated frame, sensor cable and
hydraulic hose.
[0004] In another embodiment, the invention provides a pallet for
supporting one of a
plurality of tools for a nuclear reactor retubing operation, the pallet
positionable adjacent to an
1

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
end face of a nuclear reactor core having a plurality of fuel channel
assemblies having
longitudinal axes aligned substantially parallel to each other. The pallet
includes an elongated
frame extending generally parallel to the longitudinal axes of the fuel
channel assemblies for
supporting one of the tools for the nuclear reactor retubing operation, the
frame having guide
surfaces for aligning the tool parallel to the longitudinal axes of the fuel
channel assemblies. The
pallet also includes a ram drive for pushing and pulling the tool towards and
away from the end
face of the nuclear reactor core in a direction substantially parallel to the
longitudinal axes. The
ram drive includes a ram drive connector for coupling to the tool. The pallet
is configured to
interchangeably accommodate another of the plurality of tools using the same
elongated frame
and ram drive connector.
[0005] In another embodiment, the invention provides a pallet for
supporting one of a
plurality of tools for a nuclear reactor retubing operation, the pallet
positionable adjacent to an
end face of a nuclear reactor core having a plurality of fuel channel
assemblies having
longitudinal axes aligned substantially parallel to each other. The pallet
includes an elongated
frame extending generally parallel to the longitudinal axes of the fuel
channel assemblies for
supporting one of the tools for the nuclear reactor retubing operation, the
frame having guide
surfaces for aligning the tool parallel to the longitudinal axes of the fuel
channel assemblies. The
pallet also includes a Z-axis drive for moving the elongated frame towards and
away from the
end face of the nuclear reactor core in a direction substantially parallel to
the longitudinal axes.
The pallet is configured to interchangeably accommodate another of the
plurality of tools using
the same elongated frame.
[0006] Other aspects of the invention will become apparent by consideration
of the detailed
description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a reactor core.
[0008] FIG. 2 is a perspective view of a fuel channel assembly.
2

CA 2766575 2017-02-27
Attorney Docket No. 027813-9035-CA00
[0009] FIG. 3 is a perspective view illustrating a pallet and a heavy
worktable positioned on
a retube platform for a nuclear reactor retubing operation.
[0010] FIG. 4 is an exploded perspective view of the pallet coupled to a
top of the worktable.
[0011] FIG. 5 is an exploded perspective view of the pallet illustrated in
FIG. 4.
[0012] FIG. 6 is a perspective view of a portion of the pallet illustrated
in FIG. 4.
[0013] FIG. 7 is a perspective view of a Z-drive portion of the pallet
illustrated in FIG. 5.
[0014] FIG. 8 is a perspective view of a ram drive portion of the pallet
illustrated in FIG. 6.
[0015] FIG. 9 is a magnified view of a portion of the ram drive illustrated
in FIG. 8
[0016] FIG. 10 is a magnified view of a tool coupled to the ram drive
illustrated in FIG. 5.
[0017] FIG. 11 is a schematic illustration of a portion of the ram drive
illustrated in FIG. 8.
DETAILED DESCRIPTION
[0018] 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 of components set forth in the following description or
illustrated in the following
drawings. The invention is capable of other embodiments and of being practiced
or of being
carried out in various ways.
[0019] 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. A generally cylindrical vessel, known as a calandria 10, contains a
heavy-water
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 FIG. 1, 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 along a
corresponding axis
A, which is shown in FIG. 2.
3

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
[0020] FIG. 2 is a cut-away view of the fuel channel assembly 28. As
illustrated in FIG. 2,
each fuel channel assembly 28 is surrounded by a calandria tube ("CT") 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.
[0021] 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.
[0022] 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.
[0023] As also shown in FIG. 2, an end fitting SO 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 PTs 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 FIG. 2, 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.
4

=
CA 2766575 2017-02-27
Attorney Docket No. 027813-9035-CA00
[0024] 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 FIG. 1, feeder tubes 59 are connected to
the feeder assemblies
54 that carry coolant to or away from the reactor 6.
100251 Returning to FIG. 2, 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.
[0026] 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.
100271 It should be understood that although a CANDUTm-type reactor is
illustrated in FIGS.
1 and 2, the methods and systems described below for retubing a reactor also
applies to other
types of reactors containing similar components as illustrated in FIGS. 1 and
2.
100281 During a retubing of the reactor core 6, many of the major
components of the reactor
core 6 are removed and replaced. Other components are inspected and/or
repaired. For example,
all of the fuel channel end fittings 50 are removed, all of the calandria tube
inserts 34 are
removed, the calandria tubes 32 are removed, the pressure tubes 36 are severed
from the bellows

CA 02766575 2012-01-16
=
Attorney Docket No. 027813-9035-CA00
62 and removed, and the associated annular spacers (e.g., garter springs) 48
are removed.
Various machine tools and material handling equipment must be provided
adjacent end faces 68
of the reactor core 6. In order to accommodate tooling and materials used for
at least these
processes during a retube, a pallet 72 is provided adjacent each end of the
reactor core 6. The
pallet 72 is designed to serve as a modular base for mounting and supporting
various tooling
systems and can be controlled by one or more workstations.
100291 The pallet 72 may be supported on a retube platform ("RTP") 74
erected adjacent
each end 68 of the reactor core 6. In some constructions, the pallet 72 may be
mounted to a
worktable 70 that is movable across the retube platform 74 (see FIGS. 3-4).
The pallet 72
includes a longitudinal axis B (FIG. 4) that is aligned substantially parallel
to the axes A of the
fuel channel assemblies 28. Once installed, the pallet 72 can remain on the
RTP 74 or worktable
70 for the majority of the removal series.
100301 FIG. 5 illustrates an exploded view of the pallet 72. The
pallet 72 includes an
elongated frame including a base 76 and a carriage 77. The base 76 receives a
Z-axis drive 84
and a ram drive 94. Electrical panels 79, or junction boxes, and a water-based
hydraulic
assembly 81 are coupled to the base 76. The pallet 72 may also include a
lateral drive 85 for
effectuating side-to-side movement, i.e., X-axis movement, of certain tools.
100311 The lateral drive 85 is used for material handling purposes.
When components, such
as PTs 36 or CTs 32 are removed from the reactor core 6, they are placed into
a long thin-walled
tube located on the pallet 72, called a transfer can (not shown). The working
position of a
transfer can is in alignment with the ram drive 94. To facilitate efficient
transfer can movement,
a loading position is provided on the lateral drive 85 to allow an empty
transfer can to be placed
there at the same time the pallet 72 also supports a loaded a transfer can.
Once the loaded
transfer can is removed from the pallet 72, the lateral drive 85 then moves
the unloaded transfer
can laterally to align it with the working axis of the pallet drives 84, 94.
The pallet tools are able
to pass through the transfer can to reach into the reactor core 6. The purpose
of the transfer cans
is to provide some containment around the removed reactor component in order
to limit
contamination spread and to provide standardized features for handling and
subsequent
processing of the removed material.
6

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
100321 As shown in FIG. 6, the base 76, or elongated bed, is constructed
from hollow beams
78. In other constructions, the base 76 may be constructed from other types of
beams or other
suitable structures, such as C-shaped beams, as illustrated in FIGS. 4-5. A
base 80 of the pallet
72 is provided with an interface 82 for coupling to the worktable 70 or RTP
74, as described
above. For example, as shown in FIG. 6, the interface 82 may include brackets,
or a key,
configured to engage with keyways or mating slots on the worktable 70 or RTP
74. The pallet
72 is secured to the worktable 70 or RTP 74 using threaded fasteners. In other
constructions,
other suitable interfaces may be employed. Guide surfaces 126 incorporated
with the base 76
and carriage 77 align the working axis of the end fitting flask 50, calandria
tube insert flask 34,
and calandria tube-pressure tube-garter spring 48 with the working axis of the
pallet 72 and with
the working axis of the tool thereon for easy installation.
100331 As illustrated in FIGS. 5 and 7, the Z-axis drive 84 is provided to
advance and retract
the pallet 72 relative to the worktable 70, or RTP 74, to which it is mounted
(and relative to the
reactor 6) in a Z-direction. More specifically, the Z-axis drive 84 advances
and retracts the
carriage 77 relative to the base 76. The Z-direction is defined parallel to
the longitudinal axes of
the fuel channel assemblies 28, i.e., towards and away from the end faces 68
of the reactor core
6. The Z-axis drive 84 includes a lead screw and guide system 86 coupled to
the base 76, which
is mounted on the top of the worktable 70 or RTP 74. The lead screw and guide
system 86
includes a screw 88, such as an ACME screw, and a block and nut assembly 89.
The block and
nut assembly 89 includes a traveling nut, such as a bronze ACME nut, mounted
inside a block.
The block and nut assembly 89 travels axially along the screw 88, i.e., in the
Z-axis direction,
when the screw is rotated and is self locking to prevent the assembly 89 from
being back driven.
The carriage 77 is coupled to the block and nut assembly 89, particularly to
the block, for
movement in the Z-axis direction relative to the base 76. The Z-axis drive 84
also includes a
motor 92, such as a servomotor, coupled to the screw 88 for rotating the screw
88 to effect the
linear motion of the pallet 72. In the illustrated construction, two motors 92
are employed, one at
each axial end of the screw 88, for redundancy. Motor redundancy is
particularly useful in a
nuclear reactor environment in which motors are potentially exposed to
radiation, which may
cause motor failure. A control system, such as a remote control system 93
illustrated
schematically in FIG. 4, controls the Z-axis drive 84.
7

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
[0034] Because the Z-axis drive 84 is located between the pallet 72 and the
worktable 70 or
RTP 74, the upper structure of the pallet 72 is strengthened to support heavy
flasks, and space is
made available in front of the pallet 72 for guide sleeves and shield tubes.
The pallet 72 may
function as a base tool and accommodate different tools or accessories for
calandria tube insert
release, calandria tube insert removal, and the calandria tube-pressure tube-
garter spring removal
series.
[0035] The pallet 72 further includes the ram drive 94, which can advance
and retract
accessory heads coupled to the pallet 72 with respect to the pallet 72. The
ram drive 94 may
include a drive assembly 96 (FIG. 8), such as a chain drive assembly. In the
illustrated
construction, the ram drive 94 includes a chain 98, which is preferably a semi-
rigid or "push
pull" chain configured for push and pull operation. For example, the chain 98
is a push pull
chain manufactured by Serapid, Inc. In some constructions, the chain 98 uses
links that pivot
freely one way, but lock in the opposite direction to form a rigid ram that
can be pushed (see
FIG. 11). The chain 98 forms a straight ram when the front end of the chain is
guided straight
inside a retrieval head 106 or other accessory tool. The ram drive 94 includes
a motor 110
operably coupled to drive a chain drive shaft 112 (FIG. 11). In the
illustrated construction (FIG.
8), the motor 110 includes two servomotors coupled to a 90 degree dual input
gear box 114 for
redundancy. Motor redundancy is particularly useful in a nuclear reactor
environment in which
motors are potentially exposed to radiation, which may cause motor failure.
The gear box 114
converts rotation of the motor 110 into rotation of the chain drive shaft 112,
which is coupled to
a sprocket 116 that engages the links of the chain 98 for driving the chain
98. A control system,
such as remote control system 93 shown in FIG. 4, controls the drive assembly
96. In other
constructions, other types of ram drives may be employed to push and pull the
tool towards and
away from the end face 68 of the nuclear reactor core 6.
[0036] The chain 98 may be stored or substantially enclosed within the bed
or base 76 of the
pallet 72. The chain 98 provides a long straight ram that includes a fold 100
at an intermediate
point in the chain 98 coupled with a reaction plate roller 120. A first end of
the chain 98 is fixed
at an anchor 102, which is fixed with respect to the base 76 of the pallet 72.
As illustrated in
FIG. 9, a second end of the chain 98 is coupled to a connector, such as a
quick release pin 104
and bracket 105, for coupling to the retubing tool, such as the calandria tube
retrieval head 106.
8

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
The retrieval head 106 (FIGS. 5 and 10), or other tool being employed,
includes a connection
plate 108 extending from the retrieval head 106 or other tool. The connection
plate 108 couples
to the quick release pin assembly 104 and has a substantially rectangular
cuboid shape having an
aperture therein. The rectangular cuboid shape of the connection plate 108 is
received by the
bracket 105 such that apertures in the connection plate 108 and bracket 105
align to receive the
pin 104 therethrough, thereby coupling the connection plate 108 to the bracket
105. Thus, the
retrieval head 106, or other tool being employed, is coupled to the ram drive
94 for linear motion
towards and away from the nuclear reactor 6, i.e., in the Z-direction. The
retrieval head 106
defines a longitudinal axis C that is aligned by the guide surfaces 126 to be
substantially parallel
to the axes A of the fuel channel assemblies 28, or in some cases, as
necessary, substantially
aligned with an axis A of a fuel channel assembly 28. As the first end of the
chain 98 is fixed at
the anchor 102 and the second end moves axially to drive the retrieval head
106, the fold 100
moves axially with the reaction plate roller 120 within the base 76 of the
pallet 72. The reaction
plate roller 120 acts as an idle gear for managing the different lengths of
the chain 98, e.g., to
prevent the chain 98 from folding over on itself in an uncontrolled manner or
from bending too
sharply beyond a minimum bend radius of an electrical cable 122 and hydraulic
hoses 124,
which will be described in greater detail below.
100371 As illustrated in FIG. 9, an electrical cable 122, or cables, and a
hydraulic hose 124,
or hoses, provide a conduit for electrical cables and hydraulic fluid,
respectively, to the tool or
accessory coupled to the ram drive 94, as needed. For example, the electrical
cables may include
sensor cables for sensors associated with the tool and power cables for
powering the tool, e.g.,
for powering an electric motor of the tool, as well as other electrical
cables. In some
constructions, a wireless system may communicate data from the sensors. The
hydraulic hose
124 may include two hydraulic hoses. The electrical cables 122 and hydraulic
hoses 124 thread
along the chain 98 to the quick release pin assembly 104 at the front end of
the chain 98. The
cables 122 and hoses 124 move with the chain 98 alongside the chain 98, i.e.,
are fixed with
respect to the chain 98. The accessory heads, such as the retrieval head 106
shown in FIG. 10,
mount to the quick release pin assembly 104 and, if necessary, connect to an
end of the electrical
cables 122 and hydraulic hoses 124. Another end of the electrical cables 122
may connect to the
electrical panels 79, and another end of the hydraulic hoses 124 may connect
to the hydraulic
9

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
assembly 81, which provides a pressurized fluid to the hydraulic hoses 124 and
ultimately to the
retrieval head 106 or other tool. In some constructions, the hydraulic
assembly 81 is a water
hydraulic assembly, as opposed to oil, to assure no oil is leaked into the
reactor 6 when the
accessory heads enter the reactor 6. In other constructions, the hydraulic
assembly 81 may be an
oil hydraulic assembly.
100381 The chain 98 can clear permanent vault structures while producing a
straight ram that
points towards the reactor 6. The pallet 72, including the ram drive 94 may be
operated by the
remote control system 93 shown in FIG. 4. The electrical panels 79, which are
coupled to the
pallet 72, interface with the ram drive 94, the Z-axis drive 84, the
electrical cables 122, the
lateral drive 85 and the remote control system 93. In some constructions, the
wireless system
may communicate the control signals to the pallet 72.
[0039] The pallet 72 is configured to operate within the confined space
defined by any
permanent vault structures in front of the end faces 68 of the reactor core 6.
The pallet 72 is
transported into the vault using a vault trolley system, reactor area cranes,
and floor dollies for
installation on the worktable 70 or RTP 74. Once the pallet 72 has been
installed and
commissioned on the worktable 70, for example, for pressure tube removal, it
remains on the
worktable 70 so that it can be used for calandria tube insert release,
calandria tube insert
removal, and calandria tube removal.
[0040] In operation, an operator installs a first of the retubing tools on
the pallet 72 by
connecting the tool to the pin 104 and bracket 105. Thus, the first of the
retubing tools is
configured for movement towards and away from the end face 68 of the reactor
core 6, as
described above, by way of the ram drive 94 and also by way of the Z-axis
drive 84. If
necessary, the operator also connects the sensor cable 122 to the first of the
retubing tools and, if
necessary, the operator also connects the hydraulic hose 124 to the first of
the retubing tools.
When another of the retubing tools is required for performing another portion
of the retubing
operation, the operator disconnects the first of the retubing tools and
installs a second of the
retubing tools on the pallet 72 in the same manner as described above for the
first of the retubing
tools. Thus, a first fuel channel assembly 28 component can be inserted or
removed, i.e., a first
retubing operation can be performed, using a first of the tools, and a second
retubing operation

CA 02766575 2012-01-16
Attorney Docket No. 027813-9035-CA00
can be performed using a second of the tools (etc.) without having to move the
drive components
(e.g., the ram drive 94 and the Z-axis drive 84) for the tool, the electrical
components for the tool
(e.g., the electrical cables 122 and the electrical panels 79 for the tool),
and the hydraulic
components for the tool (e.g., the hydraulic hoses 124 and the hydraulic
assembly 81). In other
words, the pallet 72 eliminates the need for each tool to have its own drive
components,
electrical components and hydraulic components, which are heavy, laborious and
time
consuming to move each time a new tool must be employed in the retubing
operation.
[0041]
Thus, the invention provides, among other things, a single pallet operable to
provide
drive components, electrical components and hydraulic components for various
insert and
removal tools and accessories. Various features and advantages of the
invention are set forth in
the following claims.
11

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2018-03-13
(22) Filed 2012-01-16
(41) Open to Public Inspection 2012-07-14
Examination Requested 2016-10-20
(45) Issued 2018-03-13

Abandonment History

There is no abandonment history.

Maintenance Fee

Last Payment of $263.14 was received on 2023-12-21


 Upcoming maintenance fee amounts

Description Date Amount
Next Payment if small entity fee 2025-01-16 $125.00
Next Payment if standard fee 2025-01-16 $347.00

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Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Application Fee $400.00 2012-01-16
Maintenance Fee - Application - New Act 2 2014-01-16 $100.00 2014-01-03
Maintenance Fee - Application - New Act 3 2015-01-16 $100.00 2015-01-13
Maintenance Fee - Application - New Act 4 2016-01-18 $100.00 2016-01-04
Request for Examination $800.00 2016-10-20
Maintenance Fee - Application - New Act 5 2017-01-16 $200.00 2017-01-04
Maintenance Fee - Application - New Act 6 2018-01-16 $200.00 2017-12-15
Final Fee $300.00 2018-01-25
Maintenance Fee - Patent - New Act 7 2019-01-16 $200.00 2019-01-15
Maintenance Fee - Patent - New Act 8 2020-01-16 $200.00 2020-01-10
Maintenance Fee - Patent - New Act 9 2021-01-18 $204.00 2021-01-08
Maintenance Fee - Patent - New Act 10 2022-01-17 $255.00 2021-12-16
Maintenance Fee - Patent - New Act 11 2023-01-16 $254.49 2022-12-16
Maintenance Fee - Patent - New Act 12 2024-01-16 $263.14 2023-12-21
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
ATOMIC ENERGY OF CANADA LIMITED
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Abstract 2012-01-16 1 24
Description 2012-01-16 11 619
Claims 2012-01-16 4 167
Drawings 2012-01-16 10 332
Representative Drawing 2012-03-13 1 24
Cover Page 2012-07-10 2 65
Amendment 2017-07-12 3 77
Claims 2017-07-12 4 155
Final Fee 2018-01-25 2 73
Representative Drawing 2018-02-12 1 25
Cover Page 2018-02-12 2 64
Assignment 2012-01-16 6 176
Special Order 2016-10-20 1 51
Correspondence 2016-10-26 1 27
Examiner Requisition 2016-11-28 6 289
Amendment 2017-02-27 20 1,125
Drawings 2017-02-27 10 335
Claims 2017-02-27 4 158
Description 2017-02-27 11 614
Examiner Requisition 2017-04-13 4 178