Note: Descriptions are shown in the official language in which they were submitted.
CA 02488318 2008-05-05
DIMENSIONAL MEASUREMENT AND INSPECTION SYSTEM OF
CANDU FUEL BUNDLE IN-BAY OF CANDU POWER PLANT
BACKGROUND OF THE INVENITON
Field of the Invention
The present invention relates to a system of
accurately measuring a dimension of a nuclear fuel bundle
and inspecting an exterior of a nuclear fuel rod, and more
particularly, to a dimensional measurement and inspection
system of a nuclear fuel bundle in a water chamber
(Reception bay) of a CANDU power plant by which the nuclear
fuel bundle is accurately measured using linear variable
measurement sensors (LVDTs: Linear Variable Differential
Transformers) in dimension in air or water and is inspected
using a radiation tolerant camera on its surface in water
to evaluate an integrity of the nuclear fuel bundle loaded
and irradiated in a channel, and by which measured data is
utilized for the development of a new nuclear fuel to
improve safety of a heavy water reactor.
Description of the Related Art
Generally, electric power plants for generating power are
classified into a hydroelectric power plant, a thermal
power plant, a nuclear power plant and the like depending
on used power sources. As one example of a nuclear reactor
used in the nuclear power plant, there is a heavy water nuclear
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reactor (CANDU) (Hereinafter, referred to as "heavy water
reactor").
As shown in Figs. 11A and 11B, a nuclear fuel bundle
300 loaded in the heavy water reactor includes a nuclear fuel
bundle having 37-element fuel rods (Hereinafter, referred to
as "37-rod nuclear fuel bundle") or a CANDU FLEXible fueling
(CANFLEX) fuel bundle having 43-element fuel rods
(Hereinafter, referred to as "CANFLEX nuclear fuel bundle").
Each of the nuclear fuel bundles has a structure of one
center rod, six or seven inner-ring rods, twelve or fourteen
intermediate-ring rods, and eighteen or twenty-one outer-ring
rods. As shown in FIGS. 11A and 11B, the nuclear fuel bundle
300 has a plurality of nuclear fuel rods 310 fixed in
parallel and side by side. At upper and lower ends of the
nuclear fuel bundle 300, an end plate 314 and the nuclear
fuel rods 310 of each ring are fixedly welded. A spacer (not
shown) is disposed at a middle of the nuclear fuel bundle
300. If the heavy water nuclear fuel bundle is loaded and
irradiated in a nuclear fuel channel, which is in an
environment of high temperature, high pressure and high
radiation, it may be deformed. Since such deformation may
influence an entirety of the nuclear fuel bundle 300 and the
nuclear fuel channel (not shown) , accurate measurement and
inspection of a dimension are required.
In other words, a variety of data obtained through the
measurement and inspection can be utilized for entirety
evaluation of the nuclear fuel bundle 300 loaded and
irradiated in the nuclear fuel channel of the Heavy water
reactor.
However, since an automized apparatus or system for
accurately and precisely measuring or inspecting the
dimension of the nuclear fuel bundle 300 in the air or in a
water chamber of the heavy water reactor does not exist,
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there is a drawback in that the dimension of the nuclear fuel
bundle loaded and irradiated in the nuclear fuel channel of
the heavy water reactor cannot be confirmed.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been devised to
solve the aforementioned problems.
An object of the present invention is to provide a
dimensional measurement and inspection system of a nuclear
fuel bundle in a water chamber of a power plant by which a
nuclear fuel bundle loaded and irradiated in a nuclear fuel
channel can be accurately measured in dimension in air or
water and can be inspected using a radiation tolerant camera
on its surface in water to evaluate an integrity of the
nuclear fuel bundle.
Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having
ordinary skill in the art upon examination of the following
or may be learned from practice of the invention. The
objectives and other advantages of the invention may be
realized and attained by the structure particularly pointed
out in the written description and claims hereof as well as
the appended drawings.
To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied and
broadly described herein, there is provided a dimensional
measurement and inspection system of a nuclear fuel bundle in
air or water chamber (reception bay) of a heavy water nuclear
reactor, the system comprising: a dimension measuring unit
for measuring a dimension of the nuclear fuel bundle; an
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inspecting unit for moving in the lengthwise direction of the
nuclear fuel bundle, and for inspecting a surface of the
nuclear fuel bundle through a radiation tolerant camera; and
a control unit for automatically processing a variety of data
and image data, which are provided from the dimension
measuring unit and the inspecting unit, by using a control
computer,
wherein the dimension measuring unit further comprises:
a rotary unit disposed at a side position of the
inspecting unit, and rotating the nuclear fuel bundle which
is put on the rotary unit;
a length and profile measuring unit disposed at a
position adjacent to two ends of the rotary unit, and
measuring a length of the nuclear fuel bundle and a profile
of end plates of the nuclear fuel bundle which is rotated on
the rotary unit by using a plurality of linear variable
measurement sensors (LVDT); and
a diameter and profile measuring unit moving in the
lengthwise direction of the nuclear fuel bundle, and
measuring a diameter and an outward surface profile of the
nuclear fuel bundle;
whereby the nuclear fuel bundle is accurately measured
and inspected in air or water to output its resultant values.
It is to be understood that both the foregoing general
description and the following detailed description of the
present invention are exemplary and explanatory and are
intended to provide further explanation of the invention as
claimed.
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BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide
a further understanding of the invention and are incorporated
in and constitute a part of this application, illustrate
embodiment(s) of the invention and together with the
description serve to explain the principle of the invention.
In the drawings:
FIG. 1 is a view illustrating a whole construction of a
dimensional measurement and inspection system of a nuclear
fuel bundle in a water chamber of a heavy water reactor
according to the present invention;
FIG. 2 is a perspective view illustrating a dimension
measuring unit and an inspecting unit of a dimensional
j .,
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nuclear fuel bundle in a water chamber of a heavy water
reactor according to the present invention;
FIG. 4 is a sectional view illustrating a motor of a
rotary unit of a dimension measuring unit of FIG. 3;
FIG. 5 is a sectional view illustrating a rotary
cylinder of a position adjusting unit of a dimension
measuring unit of FIG. 3;
FIGS. 6A and 6B respectively are a sectional view and a
side view illustrating a rotary motor of a length and profile
measuring unit of a dimension measuring unit of FIG. 3;
FIGS. 7A, 7B and 7C respectively are a crosssectional
view, a lengthwise side view and a plane sectional view
illustrating a diameter and profile measuring unit of a
dimension measuring unit of FIG. 3;
FIGS. 8A and 8B respectively are sectional views
illustrating a left mount and a right mount of a diameter and
profile measuring unit of FIG. 7;
FIGS. 9A, 9B and 9C respectively are a plane view, a
crosssectional view and a side sectional view illustrating an
inspecting unit of FIG. 3;
FIGS. 10A and 10B respectively are a side view and a
rear side view illustrating a mirror of an inspecting unit of
FIG. 3; and
FIGS. 11A and 11B respectively are an exterior
perspective view and a horizontal sectional view illustrating
a CANDU nuclear fuel bundle according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings.
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FIG. 1 is a view illustrating a whole construction of a
dimensional measurement and inspection system of a nuclear
fuel bundle in a water chamber of a heavy water reactor.
As shown in FIG. 1, the dimensional measurement and
inspection system 1 includes a dimension measuring unit 10
for measuring a variety of dimensions of a nuclear fuel
bundle 300; an inspecting unit 150 for remotely photographing
and inspecting a surface of the nuclear fuel bundle 300; and
a control unit 200 for processing and outputting a variety of
data such as image data provided from the dimension measuring
unit 10 and the inspecting unit 150.
The dimension measuring unit 10 is positioned on a
predetermined sized support plate 12. As shown in FIG. 2 and
FIGS. 3A, 3B and 3C, overturned U-shaped frames 14 are
protruded from both corners to an upper side of the support
plate 12. A hook frame 16 is provided at a center of the
overturned U-shaped frame 14 to hang on a hook of a crane
(not shown). Accordingly, due to an operation of the crane,
the support plate 12 can be immersed up to a depth of about
10m in a water chamber (W) of a heavy water reactor shown in
FIG. 1, or lifted and moved out of the water chamber X.
The dimension measuring unit 10 mounted on the support
plate 12 includes a rotary unit 20 for rotating the nuclear
fuel bundle 300 putted at one side of the support plate 1.2.
The rotary unit 20 includes a rotary motor 22 of FIG. 4 on
the support plate 12. A driving pulley 24 is mounted at a
shaft 22a of the rotary motor 22. Further, the rotary unit
20 includes an endless track-type first belt 26a loaded on
the driving pulley 24 and a plurality of first driven pulleys
28a loaded and rotated on the first belt 26a.
Additionally, the first driven pulleys 28a are disposed
at the one ends of a plurality of rotary shafts 30 extending
in a length direction of the rotary motor 22. The rotary
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shafts 30 are rotatably disposed through support brackets 32a
and 32b, which are disposed at front and rear sides of the
rotary motor 22. Second driven pulleys 28b corresponding to
the first driven pulleys 28a are respectively connected to
the other ends of the rotary shafts 30. A third driven
pulley 28c is disposed under the second driven pulley 28b to
be loaded on the second belt 26b loaded on the second driven
pulley 28b.
The third driven pulley 28c is positioned at an
opposite side of the driving pulley 24 centering on the
rotary motor 22. Further, the third driven pulley 28c is
rotatably connected to the rear support bracket 32b.
Accordingly, if the driving pulley 24 is rotated due to the
operation of the rotary motor 22, the first belts 26a allow
the rotation of the first driven pulleys 28a. The first
driven pulleys 28a rotate the second driven pulleys 28b by
using the plurality of rotary shafts 30. The second driven
pulleys 28b rotate the third driven pulleys 28c by using the
second belt 26b in the form of an endless track.
The rotary unit 20 is disposed to hang left and right
sides of the nuclear fuel bundle 300 on the first belt 26a
and the second belt 26b when the nuclear fuel bundle 300 is
putted on the first belt 26a and the second belt 26b as shown
in FIG. 3B. In this state, the first and second belts 26a
and 26b are rotated due to the operation of the rotary motor
22. Accordingly, the nuclear fuel bundle is rotated on the
first and second belts 26a and 26b.
Additionally, a position adjusting unit 40 is provided
at the rotary unit 20 to adjust left and right positions of
the nuclear fuel bundle, which is putted on the first and
second belts 26a and 26b in proximal to the rotary unit 20.
The position adjusting unit 40 is comprised of a plurality of
rotary cylinders 42 disposed at left and right sides of and
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in parallel with the motor 22 of the rotary unit 20 as shown
in FIGS. 3B and 5. The rotary cylinders 42 are fixed to the
support brackets 32a and 32b, to which the rotary shafts 30
are fixed, by using a fixing part 42a and bolts. A pusher
block 46 is disposed at an end of a rod of the rotary
cylinder 42.
A plurality of rollers 48 are rotatably disposed at the
pusher block 46 to provide a pushing force without damaging
an end plate of the nuclear fuel bundle 300.
In other words, where the nuclear fuel bundle 300 is
putted on the first and second belts 26a and 26b of the
rotary unit, the position adjusting unit 40 accurately
adjusts the left and right positions of the nuclear fuel
bundle 300. The left and right movement of the nuclear fuel
bundle 300 is performed by activating the rotary cylinder 42
during the rotation of the nuclear fuel bundle using the
rotary motor 22 such that the nuclear fuel bundle 300 can be
adjusted in the lengthwise direction at the same time of the
rotation of the nuclear fuel bundle 300.
For this, at a position adjustment operation of the
nuclear fuel bundle 300, the left and right rotary cylinders
42 are firstly operated in a long extended state of the rod
44 to rotate the pusher block 46, which is connected to the
rod 44, from a downward state shown using a solid line to an
upward state shown using a dotted line of FIG. 5. Then, the
rod 44 is activated and gradually puled toward a cylinder
body such that the plurality of rollers 48 provided at the
pusher block 46 are adhered to an end of the nuclear fuel
bundle 300, which is being rotated, to pull the nuclear fuel
bundle 300 and to adjust the position of the nuclear fuel
bundle 300 on the first and second belts 26a and 26b. The
reason why the nuclear fuel bundle 300 is lengthwise moved
while being rotated on the first and second belts 26a and 26b
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is to minimize a local abrasion during the movement of the
nuclear fuel bundle 300.
Additionally, the dimension measuring unit 10 includes
a length and profile measuring unit 50 for measuring the
length of the nuclear fuel bundle 300 at left and right
sides of the rotary unit 20 at which the nuclear fuel bundle
300 is positioned and rotated, and measuring profile of the
nuclear fuel bundle's boss end plates 314.
The length and profile measuring unit 50 includes a
plurality of linear variable measurement sensors (LVDT) 52
each coaxially disposed at left and right sides to interpose
the rotary motor 22 therebetween; double-acting pneumatic
cylinders 54 for moving the linear variable measurement
sensors 52 to the left and right in an axial direction of
the nuclear fuel bundle 300 on the rotary unit 20; and
rotating motors 56 for rotating the linear variable
measurement sensors 52 in a circumferential direction of the
nuclear fuel bundle 300.
In other words, the linear variable measurement sensors
52 are fixed in a row on a holder 58 as shown in FIGS. 6A
and 6B. An array interval of the linear variable
measurement sensors 52 corresponds to a center of each ring
of the nuclear fuel bundle 300. That is, the lowest-
positioned linear variable measurement sensor 52 corresponds
to a center of the nuclear fuel bundle 300 and a center of
the rotating motor 56, and upper linear variable measurement
sensors 52 are linearly disposed and fixed toward an
exterior (radius) of the nuclear fuel bundle 300.
Accordingly, when the linear variable measurement
sensors 52 is rotated once, the above-arrayed linear
variable measurement sensors 52 turn once around an end
plate 314 provided at end sides of the nuclear fuel bundle
300 as shown in FIG. 3B.
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The length and profile measuring unit 50 includes the
rotating motors 56 at the left and right sides of the nuclear
fuel bundle 300 to provide a rotary force for allowing the
linear variable measurement sensors 52 to turn once around
the end plate 314 of the nuclear fuel bundle 300. A rotary
shaft of the rotating motor 56 is connected to a rear end of
the holder 58 at which the linear variable measurement
sensors 52 are mounted in a row.
Additionally, the rotating motor 56 is connected to a
moving member 54a of the double-acting pneumatic cylinder 54
through its lower support 56a. That is, the double-acting
pneumatic cylinder 54 includes the moving member 54a movably
fitted to a guide 54c provided on a slide base 54b. The
moving member 54a can be moved to the left and right along
the guide 54c by a pneumatic air applied to the double-acting
pneumatic cylinder 54.
Resultantly, the plurality of linear variable
measurement sensors 52 arranged in a row can be rotated in a
circumferential direction of the nuclear fuel bundle 300 by
the rotating motor 56, and can be moved in the lengthwise
direction of the nuclear fuel bundle 300 by the double-acting
pneumatic cylinders 54.
In case that the length and profile measuring unit 50
measures the length of the nuclear fuel bundle 300, the
double-acting pneumatic cylinders 54 are operated facing to
each other at the left and right sides of the nuclear fuel
bundle 300 to move the linear variable measurement sensors 52
toward the end plates 314 disposed at the left and right
sides of the nuclear fuel bundle 300. In this state, if touch
rods 52a of the linear variable measurement sensors 52 are in
contact with the end plate 314, the linear variable
measurement sensors 52 respectively transmit different
voltage values to a control unit 200 (described later)
CA 02488318 2004-11-23
depending on a pressed degree (intensity) of the touch rods
52a. The control unit 200 calculates a variation of a moving
distance of a corresponding linear variable measurement
sensor 52 on the basis of the outputted voltage value, and as
a result, measures the length of the nuclear fuel bundle 300
by using the variation of the moving distance of the left and
right linear variable measurement sensors 52 facing each
other.
Additionally, if the rotating motor 56 is activated in
a state where the touch rods 52a of the linear variable
measurement sensors 52 are in contact with the end plate 314,
the linear variable measurement sensors 52 rotate in the
circumferential direction of and in contact with the end
plate 314. During the rotation, the linear variable
measurement sensors 52 sequentially transmit the different
outputted voltage values depending on the profile of the
nuclear fuel bundle 300. Accordingly, the control unit 200
can reproduce, detect and output the profile of the
corresponding nuclear fuel bundle 300 on the basis of the
outputted values.
Additionally, the dimension measuring unit 10 includes
a diameter and profile measuring unit 70 for measuring the
diameter of the nuclear fuel bundle 300 having an approximate
circular shape and the profile of the nuclear fuel rod 310.
As shown in FIGS. 7A, 7B and 7C, the diameter and
profile measuring unit 70 includes a pair of linear variable
measurement sensors 72 disposed to horizontally face each
other at front and rear sides of the nuclear fuel bundle 300;
an overturned U-shaped fixing member 74 for allowing the
linear variable measurement sensors 72 to be disposed at
front and rear sides of the nuclear fuel bundle 300; and a
transfer motor 76 for moving the fixing member 74 in the
lengthwise direction of the nuclear fuel bundle 300.
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Additionally, the diameter and profile measuring unit 70
includes guide rails 78 fixed to the support plate 12 in
parallel with each other at a lower and lateral side of the
nuclear fuel bundle 300 to guide the fixing member 74 in the
lengthwise direction of the nuclear fuel bundle 300. A ball
screw 80 is rotatably disposed at a center of the guide rail
78 to be connected to a rotary shaft of the transfer motor
76, thereby allowing a forward or reverse rotation.
Further, the ball screw 80 is screwed into a moving
block 82 connected to the fixing member 74 such that the
forward or reverse rotation of the transfer motor 76 allows
the moving block 82 and the fixing member 74 to be moved to
the left and right along the guide rail 78 through the
rotation of the ball screw 80.
The diameter and profile measuring unit 70 measures the
diameter of the nuclear fuel bundle 300 and the outward
surface profile of the nuclear fuel rod 310 positioned at a
side of an outer diameter of the nuclear fuel bundle 300. The
transfer motor 76 allows the overturned U-shaped fixing
member 74 to be initially positioned at a home position
deviated from one side of the nuclear fuel bundle 300 putted
on the rotary unit 20. However, if the transfer motor 76 is
operated, the ball screw 80 is rotated. Accordingly, the
ball screw 80 allows the overturned U-shaped fixing member 74
to be moved and stopped at a predetermined position of the
one end of the nuclear fuel bundle 300.
In this state, if the front and rear pneumatic cylinders
72b are activated to move the linear variable measurement
sensors 72 toward the nuclear fuel bundle 300, an end of the
touch rod 72a has its front and rear strokes of about 5mm,
thereby causing a contact with surfaces of the nuclear fuel
rods 310, which correspond to the diameter of the nuclear
fuel bundle 300, as shown in FIG. 7A.
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Additionally, if the linear variable measurement
sensors 72 contact the nuclear fuel bundle 300 to output the
voltage values, the control unit 200 converts the voltage
values into the diameter of the nuclear fuel bundle 300. The
transfer motor 76 is additionally operated to allow the
linear variable measurement sensors 72 to be moved in the
lengthwise direction of the nuclear fuel bundle 300. In
other words, the linear variable measurement sensors 72 are
moved from one end to the other end of the nuclear fuel
bundle 300 for a continuous measurement.
Additionally, if the linear variable measurement
sensors 72 are moved in the lengthwise direction of the
nuclear fuel bundle 300 while detecting the voltage values,
the voltage values are sequentially outputted to measure the
diameter from one end to the other end of the corresponding
nuclear fuel bundle 300. The control unit converts the
detected voltage values into distance values to measure the
lengthwise profile of the nuclear fuel rods 310 in contact
with the linear variable measurement sensors 72.
Meanwhile, the diameter and profile measuring unit 70
performs the measurement, not only one time, but a plurality
of times for each of a plurality of nuclear fuel rods 310
disposed at the exterior of the nuclear fuel bundle 300. For
this, the nuclear fuel bundle 300 should be rotated on the
rotary unit 20 by a predetermined angle.
In this case, the nuclear fuel rods 310 should be
disposed on the rotary unit 20 such that the linear variable
measurement sensors 72 of the diameter and profile measuring
unit 70 detect maximal outer diameters of the nuclear fuel
rods 310. At this time, as shown in FIGS. 1 and 3B, a
reference setting sensor 90 is disposed at one side of the
rotary unit 20 to set a reference for the disposition. The
reference setting sensor 90 is comprised of Linear Variable
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Differential Transformers (LVDTs) in the same manner as the
linear variable measurement sensors 52 and 72. An interval
between the reference setting sensor 90 and the linear
variable measurement sensors 72 corresponds to an interval
between the maximal outer diameters of the nuclear fuel rods
310 respectively contacting the sensors 72 and 90.
Accordingly, if the sensor 90 detects the maximal outer
diameter of the corresponding nuclear fuel rod 310 by
allowing a touch rod 90a to be in contact with any one
nuclear fuel rod 310 of the nuclear fuel bundle 300 at a
predetermined point, the linear variable measurement sensors
72 are disposed respectively corresponding to the maximal
outer diameters of the nuclear fuel rods 310 contacting the
linear variable measurement sensors 72. This state is a
reference for rotation.
As such, the position of the reference setting sensor
90 functions as a reference point for allowing the linear
variable measurement sensors 72 provided at the diameter and
profile measuring unit 70 to exactly measure the diameter of
the nuclear fuel bundle 300. Accordingly, the position of
the reference setting sensor 90 is of importance.
Alternatively, in the above set state of the reference
point, the rotary motor 22 is rotated at a predetermined
angle depending on whether the nuclear fuel bundle 300 is a
37-rod nuclear fuel bundle or a CANFLEX nuclear fuel bundle.
The nuclear fuel bundle 300 rotated at the predetermined
angle is newly detected in diameter by contacting new nuclear
fuel rods 310 with the linear variable measurement sensors
72.
The diameter and profile measuring unit 70 interacts
with the rotary unit 20 and the reference setting sensors 90
to measure all of the diameters of the nuclear fuel rods 310
disposed at the exterior of the 37-rod nuclear fuel bundle or
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the CANFLEX nuclear fuel bundle and concurrently to measure
all of lengthwise profiles of eighteen or twenty-one nuclear
fuel rods 310.
Meanwhile, the overturned U-shaped fixing member 74 has
front and rear sensor mounts 88a and 88b having different
structures as shown in FIGS. 8A and 8B to face the linear
variable measurement sensors 72 with each other in the
diameter and profile measuring unit 70.
In other words, the front sensor mount 88a has a
vertical line structure for horizontally mounting the linear
variable measurement sensor 72, but the rear sensor mount 88b
has a tilt portion (S) at its middle side and has a line
portion (Sa) at its lower side to allow the linear variable
measurement sensor 72 to be selectively mounted at a
different tilt angle according to need.
This is because where different numbers of the nuclear
fuel rods 310 such as 37 or 43 nuclear fuel rods are to be
measured, the linear variable measurement sensors 72 should
be different in position depending on different disposition
angles of the nuclear fuel rods 310 in circumferential
directions of the nuclear fuel bundle 300.
In other words, in case that the nuclear fuel bundle
300 has 37 nuclear fuel rods 310, 18 nuclear fuel rods 310
are disposed at the exterior of the nuclear fuel bundle 300
to form nine pairs such that the nuclear fuel bundle 300 can
be maintained at a constant angle in the circumferential
direction and accordingly the linear variable measurement
sensor 72 can be horizontally disposed.
However, where the nuclear fuel bundle 300 has 43
nuclear fuel rods 310, 21 nuclear fuel rods 310 are disposed
at the exterior of the nuclear fuel bundle 300. Therefore,
some of the nuclear fuel rods 310 form pairs. Accordingly,
when the linear variable measurement sensors 72 are
CA 02488318 2004-11-23
horizontally disposed, they cannot accurately measure the
diameter and profile of the nuclear fuel bundle 300.
As such, if the nuclear fuel bundle 300 has 37 nuclear
fuel rods 310, the linear variable measurement sensors 72 of
the front and rear sensor mounts 88a and 88b are horizontally
mounted to face each other for the measurement. However, if
the nuclear fuel bundle 300 has 43 nuclear fuel rods 310, the
linear variable measurement sensor 72 of the front sensor
mount 88a is horizontally mounted and the linear variable
measurement sensor 72 of the rear sensor mount 88b is aslant
mounted on the tilt portion (S) as shown in a dotted line
such that 21 outer nuclear fuel rods should be disposed to
correspond to the interval formed in the circumferential
direction of the nuclear fuel rod 310.
By doing so, the diameter of the nuclear fuel bundle
300 and the lengthwise profiles of the nuclear fuel rods 300
can be measured.
Additionally, the inventive dimensional measurement and
inspection system 1 includes the inspecting unit 150 for
inspecting the surface of the nuclear fuel bundle 300 by
using a radiation tolerant camera 155.
The radiation tolerant camera 155 of the inspecting
unit 150 is mounted to remotely confirm as to whether or not
the nuclear fuel bundle 300 is damaged within the water
chamber (W) of the Heavy water reactor. The inspecting unit
150 also includes a driving unit for moving the radiation
tolerant camera 155.
The inspecting unit 150 includes a pair of first shaft
rails 157 for moving the camera 155 in the lengthwise
direction of the nuclear fuel bundle 300; a ball screw 159
disposed between the first shaft rails 157; and the first
driving motor 160 for forward and reverse rotations of the
ball screw 159. That is, the ball screw 159 has one end
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connected to a rotary shaft 160a of the first driving motor
160. A left and right moving block 164 combined to run on
the fist shaft rails 157 is screwed into the ball screw 159
to be horizontally moved to the left and right by the
operation of the first driving motor 160.
Additionally, a second shaft rail 166 is disposed in a
vertical direction of the first shaft rail 157 on an upper
surface of the left and right moving block 164. A front and
rear moving block 170 combined to run and move in a
lengthwise direction of the second shaft rail 166 is disposed
at the second shaft rail 166. The front and rear moving
block 170 includes roller pairs 168 horizontally disposed to
encompass and rotate at left and right sides of the second
shaft rail 166 to be combined with the second shaft rail 166
of the left and right moving block 164. Further, as shown in
FIG. 9, a second driving motor 174 is provided as a driving
source at one side of the front and rear moving block 170. A
pinion gear 176 is provided at a rotary shaft of the second
driving motor 174. The pinion gear 176 is geared into a
fixed rack gear 178 along the second shaft rail 166 at one
side of the left and right moving block 164.
Accordingly, when the second driving motor 174 is
operated, the pinion gears 176 are rotated on the rack gear
178 to allow a front and rear movement. Resultantly, the
rollers 168 of the front and rear moving block 170 are run
and moved on the second shaft rail 166 of the left and right
moving block 164.
Through the above driving mechanism, the radiation
tolerant camera 155 mounted on the front and rear moving
block 170 can access the nuclear fuel bundle in the
lengthwise direction of the nuclear fuel bundle 300 along the
first shaft rail 157 by the operation of the first driving
motor 160, and in a diameter (radius) direction of the
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nuclear fuel bundle 300 along the second shaft rail 166 by
the operation of the second driving motor 174.
Meanwhile, the radiation tolerant camera 155 remotely
adjusts an angle of a built-in lens (now shown) to perform a
lens tilting function for allowing a self-photograph using a
lens barrel.
Accordingly, the inspecting unit 150 can perform an
accurate remote image inspection of the nuclear fuel bundle
300 since the radiation tolerant camera 155 can move along
the lengthwise direction or diameter direction of the nuclear
fuel bundle 300 for close-up photographing of the nuclear
fuel bundle 300, and can photograph at various angles by
using the tilting function.
Additionally, the inspecting unit 150 includes a
plurality of mirrors 180 at an opposite side of the nuclear
fuel bundle 300, that is, at an opposite side of the camera
155, to prevent a generation of a blind spot at which the
camera 155 cannot photograph such that an end plate 314
portion, which cannot be directly photographed by the camera
155, is indirectly photographed.
The mirrors 180 are provided at both sides of the
nuclear fuel bundle 300 in FIG. 3, and are constructed to
mirror the end plate 314, which is not photographed by the
camera 155. Further, the mirror 180 includes an angle
adjustment plate 182 for adjusting a mount angle to allow a
surface of the mirror 180 to be slanted up and down as shown
in FIG. 10.
The inspecting unit 150 includes a post 184 vertically
disposed; a plurality of joint screws 186 screwed into the
post 184; the angle adjustment plate 182 fixed at one side of
the post 184 by the joint screws 186; and the mirror 180
fixed at a front side of the angle adjustment plate 182.
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Additionally, the angle adjustment plate 182 is
constructed to respectively have a plurality of circular arcs
182a for the joint screws 186, thereby maintaining an
interval corresponding to an interval between the joint
screws 186, and allowing the joint screws 186 to pass through
the circular arcs 182a.
Accordingly, by adjusting the positions of the circular
arcs 182a, a tilt angle at which the mirror is mounted can be
adjusted, and the angle can be optimally selected to set the
camera 155.
Further, the inventive dimensional measurement and
inspection system 1 includes the control unit 200 for
processing a variety of data and image data provided from the
inspecting unit 150 by using a control computer 210 to output
its result value.
As shown in FIG. 1, the control unit 200 includes a
sensor controller 212 electrically connected to each of the
sensors 52, 72 and 90 to control operations of the sensors
52, 72 and 90, and to receive and process a signal from the
sensors 52, 72 and 90; a motor controller 214 for controlling
the motors 22, 56, 76, 160 and 174 and the double-acting
pneumatic cylinders 54 to move the linear variable
measurement sensors 52 and 72 at desired positions; and a
data processing unit 216 for processing data measured by each
of the sensors 52, 72 and 90.
Additionally, the control unit 200 includes a control
computer 210 connected to the control units 212, 214 and 216
to process a variety of data, perform a necessary operation,
and control a variety of the sensors 52, 72 and 90 and the
motors 22, 56, 76, 160 and 174 depending on a preset program.
In addition, the control unit 200 includes a display
unit 230 having a control monitor and an inspection image
monitor (Television) 232. The control monitor 234 provides
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CA 02488318 2004-11-23
and outputs the processed detected values and measured
values, and displays a control state to external workers.
The inspection image monitor 232 displays the image of the
radiation tolerant camera of the inspecting unit. The control
unit 200 can additionally include an image recorder 240, a
personal computer 242 and the like to move and store a
variety of measured values and inspection images.
For operation in atmosphere or water, the inventive
dimensional measurement and inspection system 1 has a
watertight structure of a variety of important parts such as
sensors 52, 72 and 90, the motors 22, 56, 76, 160 and 174,
the cylinder 54 and the camera 155 to be injected into the
water chamber (W) of the heavy water reactor.
In case that the dimensional measurement and inspection
system 1 works in water, the dimension measuring unit 10 and
the inspecting units 150 putted on the support plate 12 are
hoisted using a hook of a crane (not shown), and then can be
injected and slowly immersed up to a depth of about 10 m of
the water chamber (W) of the heavy water reactor.
Additionally, a variety of power sources, signals,
pneumatic supply lines (K) and the like are drawn from the
immersed dimension measuring unit 10 and inspecting unit 150
to the external of the water chamber (W) . The automatic
control unit 200, which is connected to the power sources,
signals, pneumatic supply lines (K), is adjusted by the
worker at the external of the water chamber M.
In order to measure and inspect the nuclear fuel bundle
300 by using the immersed dimension measuring unit 10 and the
inspecting units 150 as described above, the corresponding
nuclear fuel bundle 300 should be putted on the rotary unit
20.
In this case, the nuclear fuel bundle 300 to be
measured and inspected is picked-up, moved and putted on the
CA 02488318 2004-11-23
first and second belts 26a and 26b of the rotary unit 20 by
using a separate handling unit (not shown) for the nuclear
fuel bundle.
Since the handling unit can employ a conventional
handling unit for stably moving the nuclear fuel bundle 300
without impact, a detailed description thereof is omitted.
As such, the present invention can accurately measure a
variety of dimensions and detect the profile of the nuclear
fuel bundle 300 putted on the rotary unit 20, and determine
whether or not the nuclear fuel bundle 300 is damaged at its
exterior surface.
Length measurement of nuclear fuel bundle and Profile
measurement of nuclear fuel bundle
For this, the present invention allows the nuclear fuel
bundle 300 putted on the first and second belts 26a and 26b
of the rotary unit 20 to be rotated owing to the driving of
the rotary motor 22. The rotary motor 22 is used to rotate
the plurality of driven pulleys 28a, 28b and 28c together
with the first and second belts 26a and 26b while rotating
the nuclear fuel bundle 300 on the first and second belts 26a
and 26b.
Additionally, the position adjusting unit 40 is
activated to move the nuclear fuel bundle 300 at a
predetermined position. In a state where the rods 44 of the
rotary cylinders 42 are long extended, the position adjusting
unit 40 is activated to rotate the pusher block 46 from the
downward state shown using the solid line of FIG. 5 to the
upward state shown using the dotted line, and to gradually
pull the rods 44 toward the cylinder body.
Accordingly, the nuclear fuel bundle 300 inclined to
the left is pulled to the right by the left pusher block 46,
and the nuclear fuel bundle 300 inclined to the right is
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pulled to the left by the right pusher block 46. The above
process is performed in a state where the nuclear fuel bundle
300 is rotated to minimize a local friction with the first
and second belts 26a and 26b.
The nuclear fuel bundle 300 adjusted in position by
using the position adjusting unit 40 is measured through the
length and profile measuring unit 50.
The length and profile measuring unit 50 operates the
double-acting pneumatic cylinders 54, which are disposed
coaxially with the nuclear fuel bundle 300 at both end sides
of the nuclear fuel bundle 300, to move the moving member
54a, which is fitted to and run at the guide 54c on the slide
base 54b, toward both sides of the nuclear fuel bundle 300.
Additionally, the plurality of linear variable
measurement sensors 52 moved toward the nuclear fuel bundle
300 through the moving member 54a are operated to allow the
touch rods 52a to be in contact with the end plate 314
prepared at both ends of the nuclear fuel bundle 300. Each
of the linear variable measurement sensors 52 transmits the
voltage values, which indicate a pressurized degree, to the
control unit 200.
Since the distance values for the voltage values are
previously programmed, the control unit can convert the
length of the corresponding nuclear fuel bundle 300 by using
the voltage value.
Four linear variable measurement sensors 52 moved
toward the both sides of the nuclear fuel bundle 300 by the
double-acting pneumatic cylinders 54 are mounted on the
holder 58 as shown in FIG. 6A, and symmetrically disposed
centering on the nuclear fuel bundle 300 as shown in FIGS. 1
and 3. The control unit programs and converts the voltage
values, which are outputted from the pairs of the linear
variable measurement sensors 52 facing with each other, to
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CA 02488318 2004-11-23
indicate the length of the nuclear fuel bundle 300 at that
point. Accordingly, the output values detected by each of
four pairs of the linear variable measurement sensors 52 can
be converted into the length of the nuclear fuel bundle 300
at four points.
If the rotating motor 56 is activated in the above
state, the linear variable measurement sensors 52 are rotated
in the circumferential direction of the nuclear fuel bundle
300. While the linear variable measurement sensors 52 are
rotated, the touch rods 52a are moved along the profile of
the nuclear fuel bundle 300 such that the linear variable
measurement sensors 52 sequentially transmit the output
values different from one another.
Accordingly, the control unit 200 can not only detect
the length of the corresponding nuclear fuel bundle 300 on
the basis of the output values but also detect and output the
profile of the corresponding nuclear fuel bundle 300 with
reference to a difference of the lengths of the
circumferential direction of the nuclear fuel bundle 300.
Diameter measurement of nuclear fuel bundle and Profile
measurement of nuclear fuel bundle
For this, the present invention uses a diameter and
profile measuring unit 70 as shown in FIGS. 7A, 7B and 7C.
In case that the diameter and profile measuring unit 70
measures the diameter of the nuclear fuel bundle 300 and the
profile of the nuclear fuel rod 310 positioned at an outer
side of the nuclear fuel bundle 300, the ball screw 80 is
rotated due to an operation of the transfer motor 76 at the
positions of the linear variable measurement sensors 72 of
the overturned U-shaped fixing member 74 out of the nuclear
fuel bundle 300. The ball screw 80 is stopped at a
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predetermined position of one side of the nuclear fuel bundle
300.
If the pneumatic cylinder 72b of the overturned U-
shaped fixing member 74 is operated by a command of the
control unit in the above state, the linear variable
measurement sensors 72 are moved toward the nuclear fuel
bundle. An end of the touch rod 72a is in contact with an
outer surface of the outer nuclear fuel rods 310
corresponding to the diameter of the nuclear fuel bundle 300.
Additionally, if the diameter of the nuclear fuel
bundle 300 is measured in the above state, the transfer motor
76 is additionally activated to move the linear variable
measurement sensors 72 in the lengthwise direction of the
nuclear fuel bundle 300, and travel the linear variable
measurement sensors 72 from one end to the other end.
Accordingly, the linear variable measurement sensors 72
move in the lengthwise direction of the nuclear fuel bundle
300 while detecting a surface profile of the corresponding
nuclear fuel rod 310. Further, the detected values, which
are obtained by measuring the surface profile of the
corresponding nuclear fuel rod in the lengthwise direction of
the nuclear fuel bundle 300, are converted into the diameter
of the nuclear fuel bundle 300 by the program of the control
unit in the lengthwise direction of the nuclear fuel rod 310
contacting with the linear variable measurement sensors 72.
Meanwhile, the diameter and profile measuring unit 70
performs the measurement, not only one time, but a plurality
of times for each of the plurality of nuclear fuel rods 310
disposed at the exterior of the nuclear fuel bundle 300.
That is, in case of the 37-rod nuclear fuel bundle, the
nuclear fuel rods 310 positioned at an external side of the
37-rod nuclear fuel bundle are eighteen in number.
Therefore, the nuclear fuel bundle 300 is rotated at least
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nine rounds on the rotary unit 20. The linear variable
measurement sensors 72 are reciprocated around the nuclear
fuel bundle 300 at nine times while measuring the diameter of
the nuclear fuel bundle 300 every length.
Further, the detected values obtained through the above
process are converted into the lengthwise profile of at least
eighteen outer nuclear fuel rods 310 for reproduction and
output.
Alternatively, the reference setting sensor 90 is
provided to accurately rotate the nuclear fuel bundle 300 at
a predetermined angle on the rotary unit 20. The reference
setting sensor 90 has a maximal diameter, which is detected
by the touch rod 90a at a predetermined point of any one of
the nuclear fuel rods 310 disposed at the outer of the
nuclear fuel bundle 300, as a reference point.
At the reference point, the front and rear linear
variable measurement sensors 72 provided at the overturned U-
shaped fixing member 74 are preset to detect the diameter of
the nuclear fuel bundle 300.
Additionally, a new pair of nuclear fuel rods 310 are
rotated using the rotary unit 20 at a predetermined angle
such that the front and rear linear variable measurement
sensors 72 measure the diameters of the pair of nuclear fuel
rods 310. If the nuclear fuel rods 310 are finally rotated
at nine times, eighteen nuclear fuel rods 310 are all
completely measured.
Further, In case that the nuclear fuel bundle 300 is
the 37-rod nuclear fuel bundle, the linear variable
measurement sensors 72 are horizontally mounted to face each
other on the front and rear sensor mounts 88a and 88b
provided at the overturned U-shaped fixing member 74. In
case that the nuclear fuel bundle 300 is the CANFLEX nuclear
fuel bundle, the linear variable measurement sensor 72 is
CA 02488318 2004-11-23
horizontally mounted on the front sensor mount 88a, and the
linear variable measurement sensor 72 is aslant mounted on
the rear sensor mount 88b as shown using the dotted line in
FIG. 8B to measure the nuclear fuel rods 310 most adjacent to
the diameter of the corresponding nuclear fuel bundle 300.
In other words, In case that the nuclear fuel bundle
300 is the CANFLEX nuclear fuel bundle, the nuclear fuel
bundle 300 is rotated at least eleven times on the rotary
unit 20 since the nuclear fuel rods 310 positioned at the
outer of the nuclear fuel bundle is twenty one in number.
The linear variable measurement sensors 72 are reciprocated
at least eleven times around the nuclear fuel bundle 300
while measuring the diameter of the nuclear fuel bundle 300
every length. Further, the detected values obtained from the
above process are converted into the lengthwise profile of at
least twenty-one outer nuclear fuel rods 310 for reproduction
and output.
Image inspection for surface of nuclear fuel bundle
The inventive dimension measuring and inspecting system
1 can precisely inspect the surface of the nuclear fuel
bundle 300 by using the radiation tolerant camera 155.
For this, the inventive radiation tolerant camera 155
can access the nuclear fuel bundle 300 by moving by about
580mm in the lengthwise direction of the nuclear fuel bundle
300 along the first shaft rail 157 due to the operation of
the first driving motor 160 of the inspecting unit 150, and
moving by about 200mm in the diameter direction of the
nuclear fuel bundle 300 due to the operation of the second
driving motor 174.
Further, the radiation tolerant camera 155 can
accurately photograph a desired portion of the nuclear fuel
bundle 300 by using a self built-in tilting function. An
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image signal is remotely transmitted to the worker through
the image controller unit 216, the control computer 210 and
the inspection image monitor 232.
Additionally, the workers can allow the camera 155 to
move to a desired position through the operation and the
tilting function of the first and second driving motors 160
and 174, and allow the image to be transmitted by
photographing the end plate 314 of the nuclear fuel bundle
300 through the mirror 180.
Further, when the image is photographed, the rotary
unit 20 is driven to rotate the nuclear fuel bundle 300 in
the circumferential direction such that the nuclear fuel rods
310 disposed at the outer of the nuclear fuel bundle 300 are
photographed in close-up by using the camera 155, and an
image capturing function of the image controller unit 216 is
used to precisely photograph the desired portion.
Resultantly, the exterior of the nuclear fuel bundle 300 can
be inspected.
Meanwhile, in the above description, a description for
a procedure of obtaining the measured values by using the
plurality of sensors 52, 72 and 90 is mainly described, and a
description for a calibration procedure of the sensors and
their parts is omitted. However, the present invention
necessarily needs a previous confirmation procedure as to
whether or not a variety of measuring parts can accurately
detect the measured values in the same manner as other
precise measuring apparatuses, and the calibration procedure
of calibrating erroneous values.
However, a detailed description of the part precision-
degree confirmation and calibration procedure for the
accurate activation and detection of the variety of parts and
elements is omitted since a general technology known to the
art can be used.
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Additionally, as an example, only some of main
procedures and functions are described in the above
description, but the present invention is not limited to
this.
S Through the measured values, the present invention can
not only measure the surface profile of the nuclear fuel rod,
the profile of the end plate of the nuclear fuel bundle, the
diameter and length of the nuclear fuel bundle and the like,
but also detect the profile of a bearing pad and a
cylindricity of the nuclear fuel bundle. Further, the
present invention can not only remotely inspect a surface
defect of the bearing pads of the nuclear fuel rods 310, a
welding portion of the end plate 314, an end cap and the
like, but also can be fully utilized even for a quality
management of various other management items.
As described above, the present invention can
accurately measure or detect the dimension of the nuclear
fuel bundle 300 in atmosphere or in the water chamber of the
Heavy water reactor, and can utilize a variety of obtained
data to evaluate the entirety of the nuclear fuel bundle
loaded and irradiated in the nuclear fuel channel.
Accordingly, the present invention has an effect in
that the nuclear fuel bundle 300 is evaluated in entirety to
improve the safety of the heavy water reactor and to be
utilized even for the development of a new CANDU nuclear
fuel.
It will be apparent to those skilled in the art that
various modifications and variations can be made in the
present invention. Thus, it is intended that the present
invention covers the modifications and variations of this
invention provided they come within the scope of the appended
claims and their equivalents.
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