Note: Descriptions are shown in the official language in which they were submitted.
RACKING BOX FOR PHWR 'FUEL ASSEMBLY
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention generally relates to a packing box
for transporting a pressurized heavy water reactor (PHWR) fuel
assembly.
Description of the Related Art
Generally, a PHWR is a kind of nuclear reactor and uses
heavy water in a moderator for moderating neutron, and a
coolant for absorbing thermal energy.
Unlike LWR (Light-water Reactor), PHWR uses natural
uranium, does not need uranium enrichment, and allows for
nuclear fuel replacement during the operation of nuclear
reactors.
FIG. 1 illustrates a PHWR fuel assembly (hereinafter "fuel
assembly"), fuel assembly 10 comprises a plurality of fuel rods
11 in which pellets are charged and a rod bonding plate 12,
which are welded and fixed to both sides of fuel rod, and a
spacer (not illustrated) is disposed in the middle of fuel rod
11.
Fuel assembly configured as above has a diameter of 130mm,
and a length of 460ma approximately, and a plurality of fuel
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assemblies are stored in a box so as to be transported.
In reference to a conventional packing box, hardboards,
etc. are inserted so as to pile up fuel assembly with
separators of expanded polystyrene (EPS) material in between
fuel assemblies for packing. Thus, packed fuel assembly is
vulnerable to external impacts. In addition, subsidiary
materials in use are composed of different materials, which
makes it difficult to recycle and handle.
Documents of Related Art
Korean Patent Publication No. 10-2010-0074205 (published
on 01 July, 2010)
SUMMARY OF THE INVENTION
Accordingly, the present invention relates to a packing
box for PHWR fuel assembly which can protect fuel assembly
safely from external impact, be easy to recycle and handle in
transportation.
In order to achieve the above object, a packing box for
transporting PHWR fuel assemblies according to the present
invention comprises a rectangular bottom cell comprising a
bottom tray having an upper surface defining a plurality of
longitudinal parallel first positioning grooves, and first
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locking protrusions disposed at opposing sides of the bottom
tray adjacent the outermost first positioning grooves; a
rectagular planar middle cell comprising a middle tray having a
bottom surface defining a plurality of first fixing grooves,
and an upper surface defining a plurality of second positioning
groovesõ wherein each first fixing groove corresponds to one
of the first positioning grooves of the bote.om cell, and second
locking protrusions disposed at opposing sides of the middle
tray, adjacent the outermost second positioning grooves; and a
rectangular planar top cell comprising a top tray having a
bottom surface defining a plurality of second fixing grooves,
wherein each second fixing groove corresponds to one of the
second positioning grooves of the middle tray; wherein the
bottom cell, middle cell and top cell assemble together to
retain PHWR fuel assemblies between them within the positioning
and fixing grooves.
Preferably, according to the present invention, the fixing
groove and the positioning groove have the same radius of
curvature. However, the fixing groove is characterized by
having a sector angle larger than a sector angle of the
positioning groove.
Preferably, according to the present invention, the middle
cell is assembled to the bottom cell through insertion of the
first locking protrusions into the middle cell.
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Preferably, according to the present invention, the top
cell is assembled to the middle cell through insertion of the
second locking protrusions into the top cell.
Preferably, according to the present invention, the bottom
tray and the middle tray are characterized by having a standard
marker at both longitudinal ends to show the standard position
of the PHWR fuel assemblies within the positioning grooves.
Preferably, according to the present invention, the bottom
cell further comprises a protrusion formed on a lower side of
the bottom cell, wherein the protrusion is sized and shaped to
fit wihtin spaces between plates of a pallet, and cooperate
with the pallet to limit horizontal movement of the bottom cell
relative to the pallet.
Preferably, according to the present invention, the bottom
surface of the middle tray and the bottom surface of the top
tray are characterized by separation walls separating two PHWR
fuel assemblies retained within each of the fixing grooves.
The present invention has the following advantages.
Packing box for transporting PHWR fuel assembly according
to the present invention comprises a bottom cell, a middle
cell, and a top cell. Thus, a plurality of fuel assemblies can
be stored safely in between each cell. Especially waste of
unnecessary packing materials can be prevented because packing
material is made of a single material such as EPP material,
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etc.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other advantages
of the present invention will be more clearly understood from
the following detailed description when taken in conjunction
with the accompanying drawings, in which:
FIG. 1 illustrates a perspective view of PEWR fuel
assembly according to the present invention.
FIG. 2 illustrates a perspective view of a packing box
according to the present invention.
FIG. 3 illustrates an exploded perspective view of a
packing box according to the present invention.
FIG. 4 (a) and (b) illustrate a plane figure and a front
view of a bottom cell each for a packing box according to the
present invention.
FIG. 5 (a) and (b) illustrate a perspective view of a
middle cell and a perspective view in reversed condition each
for a packing box according to the present invention.
FIG. 6 (a) and (b) illustrate a section view of A-A line
and a section view of B-B line in FIG. 5 (a).
FIG. 7 (a) and (b) illustrate a perspective view of a top
cell and a perspective view of reversed condition for a packing
box according to the present invention.
FIG. 8 (a) and (b) illustrate a section view of C-C line
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and a section view of D-D line in FIG. 7 (a).
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present
invention will be described in detail with reference to the
accompanying drawings. Throughout
the drawings, the same
reference numerals will refer to the same or like parts.
Specific structures and functional descriptions presented
in the embodiments of the present invention are illustrated
only for the purpose of illustrating the embodiments according
to the concept of the present invention and the embodiment
according to the concept of the invention can be conducted in
various forms. Also it cannot be construed that the invention
is limited to the embodiments described herein. It should be
understood that the invention includes various modifications,
equivalents, and substitutions without departing from the scope
and spirit of the invention.
Although a preferred embodiment of the present invention
has been described for illustrative purposes, those skilled in
the art will appreciate that various modifications, additions
and substitutions are possible, without departing from the
scope and spirit of the invention as disclosed in the
accompanying claims.
Meanwhile in the present invention, terms such as the
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first and/or the second may be used to describe various
components. However, the components are not limited to the
above terms. These terms are only to distinguish one component
and another component, for example in the range without
departing from the scope of the concept of the present
invention, and the first component could be termed a second
component. Similarly, the second component could be termed the
first component.
If there is a statement that one component is "connected"
M or "accessed" to another component, it can mean that one
component is "connected" or "accessed" directly to another
component or another different component can exist in the
middle. On the other hand, if there is a statement that one
component is "directly connected" or "directly accessed" to
another component, it means that another component does not
exist in the middle. Other terms for describing relations
between components such as "between-", and "right between-", or
"adjacent to-" and "directly adjacent to-", etc. should be
understood in the same manner as above.
Hereinafter, exemplary embodiments of the present
invention will be described in detail with reference to the
accompanying drawings. Throughout
the drawings, the same
reference numerals will refer to the same or like parts from
configuration of bilateral symmetry or duplication unless extra
division is needed.
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In reference to FIG. 2, a packing box according to the
present invention has a structure that a bottom cell 100, a
middle cell 200, and a top cell 300 are piled up sequentially.
A plurality of fuel assemblies is stored in-between the
cells. For reference, one middle cell is illustrated in the
present embodiment, but it should be understood that more than
two middle cells which are identical structurally can be piled.
A bottom cell, a middle cell, and a top cell which form a
packing box according to the present invention can be made of
expanded polypropylene (EPP) material, which has superior flame
retardant and durability of abrasion properties. Various
materials can be chosen to be used as long as they do not
hinder flame retardant and durability.
The packing box can be positioned on a pallet 400, and
transported by a forklift, etc.
The packing box positioned on a pallet 400 can be packed
by an enclosure made of metal material.
Meanwhile, wood can be used for a pallet 400, but
recyclable stainless steel preferably can be used for solidity
and a decontamination process.
A top plate of a pallet 400 has a plurality of plates 410
placed with separation distance so that space can be prepared
between plates 410, and the bumpy part in a lower side of the
bottom cell 100 can be locked between plates 410.
Insert nuts 401 can be arranged on the edge of a pallet
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400 so as to be connected to an enclosure (not illustrated),
and pads such as rubber, etc. can be arranged in the bottom
side for prevention of slipperiness.
In reference to FIG. 3, a bottom cell 100 has a
rectangular plane structure, a first positioning groove 111 is
arranged in more than two rows so that a plurality of fuel
assemblies can be stored on the surface side by side, and a
first locking protrusion 120 is arranged protrusively in both
ends of a first positioning groove 111.
The first positioning groove 111 and the first locking
protrusion 120 are arranged on the surface of the bottom cell
100 with a difference in levels.
Specifically, in reference to FIG. 4 (a) and (b), a bottom
cell 100 includes a rectangular base plate 101, a an upper
surface of a bottom tray 110 have a positioning groove 111 with
difference in level in more than two rows side by side on the
surface of the base plate 101 and a first locking protrusion
120 is arranged in both end rows of the upper surface of the
bottom tray 110.
The upper surface of the bottom tray 110 includes more
than two rows of positioning grooves 111 formed in curvature
side by side with the same curvature as the external diameter
of fuel assembly 10, and one or more than two fuel assemblies
10 are positioned in each positioning groove 111. In the
present embodiment, two fuel assemblies are accommodated in a
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single groove 111.
Each positioning groove 111 is connected to a horizontal
plane 112 of a constant width, preferably a standard marker
112a is prepared in both ends so as to show the standard
position of fuel assembly to be positioned in the positioning
groove 111.
Meanwhile, the width of the horizontal plane 112 can be
determined so as to keep an appropriate distance between fuel
assemblies 10.
A first locking protrusion 120 is arranged at both end
rows of the upper surface of the bottom tray 110 in bilateral
symmetry, and formed protrusively higher than the upper surface
of the bottom tray 110 by a constant height("h"), so as to
prevent positioned fuel assembly in the positioning groove 111
from falling out of the bottom cell 100.
Meanwhile, a lower side of a base plate 101 can comprise
further protrusively loused bumpy part 130, which can guide the
upper side of the pallet 400 for positioning in a right
position by cooperating with the pallet 400 (see FIG. 3), limit
horizontal movement of the bottom cell 100, and prevent a
packing box in transportation from falling out of the pallet
400.
The bumpy part 130 can be a block of a constant thickness,
appropriately positioned in the lowsr side of the base plate
101, and determined properly according to the structure of
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positioning plane of the pallet 400.
In reference to FIGS. 5(a) and (b), the middle cell 200
includes a first body part 201 of a hull structure with the
lower part open, a bottom surface 210 of a middle tray having a
fixing groove 211 formed in curvature so as to correspond to
each positioning groove 111 of the upper surface of the bottom
tray 110 of the bottom cell (see FIGS. 4(a) and (b)) in the
lower part of the first body part 201, and the upper part
further comprises an upper surface of the middle tray 220
having more than two roWs of a positioning grooves 221 formed
in curvature side by side, and a second locking protrusion 230
which is formed protrusively higher than the upper surface of
the middle tray, and arranged in both end rows of the upper
surface of the middle tray 220.
The upper part of the middle cell 200 is comprised of the
upper surface of the middle tray 220 and the second locking
protrusion 230 whose structure is substantially identical to
the upper part of the bottom cell. Thus, the duplicated
explanation is not given.
As illustrated in FIG. 5(b), the bottom surface of the
middle tray 210 having a fixing groove 211 formed in curvature
so as to each positioning groove of the upper surface of the
bottom tray 110 is arranged in the lower part of a middle cell
200, and each fixing groove 211 and the positioning groove 111
of the upper surface of the bottom tray 110 have the same
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curvature as fuel assembly.
Specifically, in reference to FIG. 6(a), a fixing groove
211 has a semicylindric fixed plane 211a, and a taper plane
211b which expands with a constant slope at an open end.
A fixed plane has substantially the same radius of
curvature("r"), as fuel assembly 10, the sector angle 02 of the
fixed plane 211a is larger than the sector angle 01 of the
positioning groove 221 (01<02), and preferably does not exceed
a maximum sector angle of 1800
.
The fixing groove 211 having these fixed plane 211a and
taper plane 211b has the structure for wrapping fuel assembly
as much as possible, and can be easily assembled with fuel
assembly 10 by the taper plane with an extended slope.
As illustrated in FIG. 6(b), a separation wall 212 formed
protrusively and vertically is arranged in the fixing groove
211 in such a way that more than two fuel assemblies can be
accommodated in a fixing groove 211 corresponding to a row, and
two fuel assemblies can be accommodated in a separated space.
In reference to FIGS. 5(a) and (b), a plurality of
gripping part 201a formed concavely is arranged around the
first body part 201 so as to increase operator's convenience
during the process of opening or closing the middle cell 200.
In addition, the first body part 201 can comprise an
assembly hole 201b in which the indicator on the impact can be
attached.
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In reference to FIGS. 7(a) and (b) and FIGS. 8(a) and (b),
a top cell 300 includes the second body part 301 made of a hull
structure, a bottom surface of top tray 310 having a fixing
groove 311 formed in curvature corresponding to the upper
surface of the middle tray 220 is arranged in the lower part
of the second body part 301 so as to be assembled to the upper
part of the middle cell 200 by insertion.
The lower part of the top cell 300 is comprised of the
bottom surface of the top tray 310 whose structure is
substantially identical to the bottom surface of the middle
tray 210 of the middle cell. Thus, the duplicated explanation
is not given or reproduced here.
The upper plane of the second body part 301 is made flat
so as to enable a two-step load, and a plurality of gripping
parts 301a is arranged around that so as to increase operator's
convenience during the process of opening or closing the top
cell 300.
In addition, corners of the second body part 301 are
desired to be rounded or chamfered so as to prevent an
operator's injury while handling the packing box.
At the corner of the second body part 301, a corner plate
301b is arranged in a position in which ties are tied for
connecting with the pallet. Thus, the corner plate prevents
corners of the top cell from being damaged by ties holding a
packing box.
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It is apparent to those who are skilled in the art that .
the present invention described above is not limited by the
aforementioned embodiments and the accompanying drawings, and a
number of substitutions, modifications and changes are possible
without departing from the scope of the technical concept of
the present invention.
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