JP7183898B2 - fuel holder - Google Patents

Description

The present invention relates to a fuel holder that accommodates a fuel assembly.

Conventionally, when transporting a nuclear fuel assembly for a nuclear reactor such as MOX fuel, the nuclear fuel assembly is housed in a fuel holder, and this fuel holder is inserted into a plurality of logistic holes provided in a transportation container for transportation ( See Patent Documents 1 and 2). This fuel holder is constructed by connecting a lid body having an L-shaped cross section and a container body having an L-shaped cross section so that they can be opened and closed by connecting means, and the lid body cannot be opened when closed. It is locked to the container body by the locking means.

When housing the nuclear fuel assembly in the fuel holder, first, the fuel holder is placed in an upright state so that the top portion faces upward, and the lid is opened. After opening the lid, the nuclear fuel assemblies are accommodated and the lid is closed again. Then, the lid is locked to the container body so that the lid cannot be opened.

Currently, the work of storing these nuclear fuel assemblies is carried out by workers, but in order to shorten the work time and reduce exposure to radiation, part or all of the work is being done by remote control devices (such as robots). expected to do so.

Japanese Patent No. 3080895 Japanese Patent No. 6040335

By the way, since the lid body and the container body of the fuel holder are as long as about 5 m and are formed of a thin plate material with a thickness of about 5 mm, the fuel holder is not deformed by material processing such as welding, bending, and punching. have.

Due to such distortion and processing accuracy, when the nuclear fuel assembly is inserted into (or removed from) the transport container, the locking means may not come to the designed position simply by closing the lid. For example, it is necessary to press the lid against the container body to some extent or pull the lid toward the opening side. However, even if the cover is pushed too much or pulled too much, the positions of the locking means do not match.

Also, when releasing the locked state by the locking means, if the locking means is not positioned as designed, the locking pin may bend. It was not possible to pull it out, and it was difficult to perform an opening operation at the time of removal work only with the remote control device.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a fuel holder that facilitates locking or releasing of locking means.

(1) According to one aspect of the present invention, a storage space for storing a fuel assembly is formed by a first half-split body and a second half-split body having two orthogonal wall portions, a top portion, and a bottom portion. a connecting means for connecting the first half-split body and the second half-split body so as to be openable and closable; and locking means for stopping the fuel holder, and further comprising a position regulating means for regulating the mutual positions of the first half-split body and the second half-split body when closed.
(2) In the above aspect (1), the position restricting means is an abutting portion provided on the inner surface of the wall surface portion of one of the first half-split body and the second half-split body; The abutting portion may directly abut on the inner surface of the wall surface portion of the other of the first half body and the second half body when closed.
(3) In the aspect (1) or (2) above, the position restricting means is the connecting means of the end sides of the two wall surface portions of the first half and the second half. abutting portion or stopping portion provided on the side of the free side that is not connected by the two, and the striking portion and the stopping portion may be in direct contact with each other.
(4) In any one aspect from (1) to (3) above, the locking means includes a retractable locking pin and a locking hole into which the locking pin is fitted, and A pin is inserted into a hole in a locking holder attached to one of said first half or said second half, said locking hole being aligned with said first half or said second half. It may be formed in a locking block attached to the other of the splits.
(5) In the aspect of (4) above, the locking pin may be formed in a tapered conical shape at the opposite end that does not face the locking block.
(6) Another aspect of the present invention is an accommodation space for accommodating a fuel assembly with a first half body and a second half body having two orthogonal wall portions, a top portion, and a bottom portion. a connecting means for connecting the first half and the second half so that they can be opened and closed; locking means for locking to the The locking pin is formed in a locking block attached to the other of the first half and the second half, and the locking pin is attached to one of the first half and the second half. It is inserted into the hole of the locking holder attached to one side, and the tip of the other side, which does not face the locking block, is tapered into a conical shape.
(7) In any one aspect from (4) to (6) above, the locking pin may be formed in a conical shape with a tapered tip on the locking block side.
(8) In any one of the aspects (1) to (7) above, at least one of the connecting means and the locking means may be provided so as not to protrude from the outer surface of the housing shell.

According to the present invention, it is possible to provide a fuel holder that facilitates locking or releasing of locking means.

FIG. 3 is a cross-sectional view showing a transportation container equipped with a fuel holder according to an embodiment of the present invention; It is an explanatory view showing a fuel holder of an embodiment concerning the present invention. 3 is an enlarged cross-sectional view taken along line BB of FIG. 2 showing connecting means and locking means of the fuel holder; FIG. It is explanatory drawing which shows a connection means. FIG. 3 is an enlarged cross-sectional view taken along line CC of FIG. 2 showing the position restricting means of the fuel holder; FIG. 5 is an explanatory diagram showing a position regulation procedure of a position regulation means; It is an explanatory view showing a locking block. It is an explanatory view showing a locking pin. It is an explanatory view showing a locking holder. It is explanatory drawing which shows the locking point of a locking means. FIG. 3 is a view corresponding to an enlarged cross-sectional view taken along line DD in FIG. 2 showing locking means and position regulating means of the fuel holder of modification 1; FIG. 11 is an explanatory diagram showing a position regulation procedure of a position regulation means of modification 1;

An embodiment of the present invention will be described in detail below with reference to the drawings. The same reference numerals are assigned to the same elements throughout the description of the embodiment.

FIG. 1 is a cross-sectional view showing a transportation container 100 equipped with a fuel holder 1 according to an embodiment of the present invention.
The fuel holder 1, as shown in FIG. 1, is attached to a rectangular loggiment hole 101 provided in a transport container 100 and transported. This fuel holder 1 accommodates a fuel assembly (not shown) such as nuclear fuel for a nuclear reactor, such as mixed oxide fuel (MOX fuel). Note that the transportation container 100 is laid on its side during transportation, and is set vertically when the fuel holder 1 is inserted or removed.

2A and 2B are explanatory views showing the fuel holder 1 of the embodiment according to the present invention, and are (a) a front view, (b) a bottom view, (c) a right side view, and (d) a left side view.

Further, the fuel holder 1 is provided with a housing shell 2 for housing the fuel assembly, as shown in FIG. In the housing shell 2, the first half 10, the second half 20, the top 30, and the bottom 40 form a housing space for housing the fuel assembly. The material of the first half 10, the second half 20, the top 30, the bottom 40, etc., which constitute the housing shell 2, depends on the required strength and heat resistance depending on the size and weight of the fuel assembly to be housed. Although it is selected as appropriate in consideration of this, it is usually stainless steel such as SUS304 or a heat-resistant nickel-based alloy.

The first half-split body 10 has an L-shaped cross section formed by bending a single plate material with a thickness of about 5 mm, and has two orthogonal wall portions 11 and 12 (see FIG. 2 ( d) see). The wall portions 11 and 12 have upper guides 80 on the top portion 30 side.

The upper guide 80 is formed of a leaf spring in an arc shape or a tapered shape with a higher top portion 30 side when viewed from the side. The upper guide 80 urges the fuel holder 1 against the inner surface of the logistic hole 101 of the transportation container 100 to fix the fuel holder 1 to the logistic hole 101 and prevent displacement due to vibration during transportation. ing. At this time, the first half-split body 10 is inserted and mounted so as to be on the upper side of the logiment hole 101 during transportation. Conversely, the second half-split body 20 is inserted and mounted so as to be on the lower side of the logiment hole 101 during transportation.

Next, the second half-split body 20, like the first half-split body 10, is formed by bending a plate material having a thickness of about 5 mm and has an L-shaped cross section. wall portions 21 and 22 (see FIG. 2(d)). A top portion 30 and a bottom portion 40 are attached to the second half 20 . The wall surfaces 21 and 22 of the second half-split body 20 are provided with top flanges (not shown) contacting the top surface of the logiment hole 101 on the top portion 30 side of the upper guide 80 .

A plurality of heat radiation windows 70 are formed in the wall surface portions 11 , 12 , 21 , 22 of the first half 10 and the second half 20 . This radiation window 70 is for releasing decay heat due to nuclear fission of the fuel assembly accommodated in the fuel holder 1 to the outside, and is formed in a square opening such as a square, a rectangle, or a parallelogram.

In the radiation window 70, at least the peripheral edges of the outer surfaces on the top portion 30 side and the bottom portion 40 side are chamfered, but it is preferable that the remaining peripheral edges including the inner surface are also chamfered.

Further, the heat radiation window 70 closest to the top portion 30 side or the bottom portion 40 side is preferably formed in an axially elongated rectangular opening connecting the top portion 30 and the bottom portion 40 . Since the opening area of the radiation window 70 is set by calculation from decay heat and the like, it cannot be reduced. The strength in the axial direction connecting the top portion 30 and the bottom portion 40 of the fuel holder 1, that is, the buckling strength can be increased. Therefore, the periphery of the radiation window 70 in the direction perpendicular to the insertion direction of the fuel holder 1 does not bulge outward and deform.

The top portion 30 closes the top of the fuel holder 1, and is provided with hanging jigs (not shown) such as eyebolts and hooks used when the fuel holder 1 is placed vertically. This top portion 30 is attached to the second half 20 by welding.

The bottom part 40 has, for example, a lower roller 60 on the side surface near the lower end on the first half 10 side. By urging the fuel holder 1 against the inner surface of the logiment hole 101 of the transport container 100, the lower roller 60 urges the fuel holder 1 to the logiment hole 101 to fix (lock) the fuel holder 1 to one side and prevent vibrations during transportation. This prevents misalignment due to

Next, the connecting means 3 and the locking means 4 will be explained. FIG. 3 is an enlarged cross-sectional view taken along line BB of FIG. 4A and 4B are explanatory diagrams showing the connecting means 3, and are (a) a front view and (b) a right side view.

As shown in FIG. 3, the first half body 10 and the second half body 20 are connected to each other by connecting means 3 so as to be openable and closable. Also, the first half-split body 10 and the second half-split body 20 are locked to each other by locking means 4 so that the fuel holder 1 does not open (release) during transportation. In other words, the first half 10 and the second half 20 cannot be opened from each other while the locking means 4 is in operation.

A so-called hinge (hereinafter referred to as "hinge 3") shown in FIG. This hinge 3 is provided so as not to protrude from the outer surface of the housing shell 2 . That is, the wall surfaces 11 and 21 are counter-bored to a depth equal to or greater than the thickness of the wing plates of the hinge 3, and the hinge 3 is attached with countersunk bolts or the like. By providing the hinge 3 in this manner, it does not protrude from the outer surface of the wall surface portions 11 and 21 .

On the other hand, locking means 4 for locking the first half-split body 10 and the second half-split body 20 are provided diagonally of the connecting means 3 . A detailed structure of the locking means 4 will be described later.

Here, the fuel holder 1 further includes a position regulating means 5 for regulating the positions of the first half 10 and the second half 20 when closed. FIG. 5 is an enlarged cross-sectional view taken along line CC of FIG. 6A and 6B are explanatory diagrams showing the position control procedure of the position control means 5, in (a) closed state and (b) open state. In addition, in FIG.6(b), the 2nd half-split body 20 is actually open|released by an arc-shaped track|orbit.

The position regulating means 5 is formed as an abutment means (hereinafter referred to as "abutment means 5") provided on the inner surface of the wall surface portion 12 of the first half-split body 10. As shown in FIG. The abutting means 5 is provided with a plurality of abutting portions 15 in the vicinity of the plurality of locking means 4, so that even if the second half-split body 20 is pressed against the first half-split body 10 by a remote control device, the abutting portion 15 will not be hit. It is designed so that it cannot move beyond contact (see FIG. 6).

The abutment portion 15 is formed of a substantially triangular prism-shaped member having an abutment surface 15b that directly abuts against the abutted surface 22b on the inner surface of the wall surface portion 22 of the second half-split body 20 when closed. Here, a separate member may be provided on the inner surface of the wall surface portion 22 of the second half-split body 20, and the separate member may be ground (or cut) to form the contacted surface 22b. Grinding (or cutting) the abutment surface 15b and the abutted surface 22b improves the flatness of each surface, thereby improving the position regulation (positioning) accuracy.

The abutting portion 15 may be provided on the inner surface of the second half-split body 20 and may directly abut against the wall surface portion 12 of the first half-split body 10 when closed, or may be in contact with the corner on the same side as the connecting means 3 . may be provided in the department.

Returning to FIG. 3, the locking means 4 will be explained again. 7A and 7B are explanatory views showing the locking block 14, and are (a) a front cross-sectional view and (b) a right side view. FIG. 8 is a front view showing the locking pin 24. FIG. 9A and 9B are explanatory views showing the locking holder 25, and are (a) a front view, (b) a right side view, and (c) a top view. 10A and 10B are explanatory diagrams showing the locking procedure of the locking means 4. FIG. 10A is a front view, and FIG. 10B is a cross-sectional view taken along line EE.

As shown in FIG. 10, the locking means 4 engages a locking pin 24 movably provided on the second half 20 in a locking hole 14a provided in the first half 10. Thus, the first half 10 and the second half 20 are locked.

The locking hole 14a is formed in a locking block 14 fixed to the inner surface of the wall surface 12 by a countersunk bolt or the like, and faces the front end 24s of the locking pin 24. As shown in FIG. However, the locking hole 14a is located on the bottom portion 40 side, and the locking pin 24 is located on the top portion 30 side and faces each other.

7A, the locking hole 14a includes a first tapered hole 14a1 on the side of the locking pin 24, a second tapered hole 14a2, a first tapered hole 14a1 and a second tapered hole 14a2. and a straight hole 14a3 and a prepared hole 14a4.

Of these, the first tapered hole 14a1 guides the front end 24s of the locking pin 24 and has a taper angle θ3 of 60° or more and 90° or less. has a taper angle .theta.4 equal to the taper angle .theta.1 at the front end tapered portion 24f.

On the other hand, the locking pin 24 is provided movably with respect to a locking holder 25 fixed to the inner surface side of the wall surface portion 22 by a countersunk bolt or the like. As shown in FIG. 8, the locking pin 24 is formed as a front end tapered portion 24f having a tapered conical shape (a tapered shape when viewed in cross section), and a front end 24s is formed as a spherical surface SR. ing. Further, the locking pin 24 is formed as a rear end tapered portion 24r having a tapered conical shape (tapered shape when viewed in cross section) at the opposite end that does not face the locking block 14 .

In addition, the locking pin 24 (preferably, rather than the rear end tapered portion 24r) is less likely to get caught in the opening of the groove 28 of the locking holder 25, which will be described later, when the locking means 4 is released. It is preferable that the rear end tapered portion 24r side is formed to have a length that is not exposed from the groove 28 (that is, it cannot be visually recognized).

The front end taper portion 24f has a taper angle θ1 of 45° or more and 60° or less, and the rear end taper portion 24r has a taper angle θ2 of 45° or more and 60° or less. Note that the taper angle θ1 and the taper angle θ2 may be different angles. An operation means 26 such as a bolt is attached to the locking pin 24 .

The locking holder 25 is formed with a hole 25a that holds the locking pin 24 so as to be movable (protrusible and retractable), and an elastic member 27 such as a coil spring is installed on the far side of the hole 25a (see FIG. 10). . A groove 28 for guiding the shaft portion of the operating means 26 is formed in the locking holder 25 from the wall surface portion 12 side toward the wall surface portion 22 . More specifically, the groove 28 includes a groove 28a extending toward the distal end of the locking pin 24 (direction of the locking hole 14a) on the wall surface portion 22 side, and a groove 28a extending toward the distal end of the locking pin 24 (the direction of the locking hole 14a) on the wall surface portion 12 side. The groove 28b extends toward the locking hole 14a) and is longer than the groove 28a, and the groove 28c communicates with the groove 28a and the groove 28b (see FIG. 9).

When the first half-split body 10 and the second half-split body 20 are to be latched using such a latching means 4, first, the operation means 26 is positioned on the side of the groove 28a, and the latching pin 24 is pulled. keep it in. Then, the end faces (free sides 12a, 22a) opposite to the end faces (fixed sides 11a, 21a) of the first half body 10 and the second half body 20 connected by the connecting means 3 are brought into contact with each other. After that, when the operating means 26 is grasped by a remote control device or an operator and moved toward the groove 28b, the locking pin 24 to which the operating means 26 is attached is biased by the elastic member 27 and begins to protrude and is locked. It is fitted (inserted) into the locking hole 14a of the block 14 and locked.

At this time, that is, in the locked state of the first half-split body 10 and the second half-split body 20, the head portion of the operating means 26 does not protrude from the outer surface of the second half-split body 20 (see FIG. 3). ). Further, since the locking pin 24 is urged toward the front end 24s by the elastic member 27 attached to the rear end tapered portion 24r, the locking pin 24 may move out of the locking hole 14a due to vibration during transportation. There is no way out of

Since the locking state between the locking hole 14a and the locking pin 24 is a relative relationship, the locking block 14 (locking hole 14a) is provided on the second half-split body 20 side, A pin 24 may be provided on the first half 10 side.

By the way, the position regulating means 5 of the above embodiment is formed as abutting means, but the position regulating means 50 of Modification 1 is formed as a locating means (hereinafter referred to as "locating means 50"). .
FIG. 11 is a diagram corresponding to an enlarged cross-sectional view taken along line DD in FIG. 12A and 12B are explanatory diagrams showing the position regulation procedure of the position regulation means 50 of Modification 1, in (a) the closed state and (b) the open state. In addition, in FIG. 12(a), the first half-split body 10 is not shown, and in FIG. 12(b), the first half-split body 10 is actually opened in an arc-shaped orbit.

The locating means 50 is connected by the connecting means 3 among the end sides 11a, 12a, 21a, 22a of the two wall surface portions 11, 12, 21, 22 of the first half body 10 and the second half body 20. These are a stopper portion 51 and a thrust receiving portion 52 provided on the free sides 12a and 22a on the side that is not connected (the side different from the fixed sides 11a and 21a connected by the connecting means 3).

The stop portion 51 and the abutment portion 52 are directly formed integrally with a part of the locking block 14 and the locking holder 25 of the locking means 4, but are formed as separate parts and attached to the locking means 4. It may be fixed, or it may be formed as a separate part independent from the locking means 4 and provided in the vicinity of the locking means 4 .

The abutting portion 52 is formed in a concave shape having, for example, a first abutting surface 52a on the outer side and a second abutting surface 52b on the inner side with respect to the fuel holder 1 . When the direction in which the wall surface portion 12 extends is taken as a reference plane, the first abutment surface 52a is inclined outward by 40° from the reference plane, and the second abutment surface 52b is inclined inward by 50° from the reference plane. Although they are inclined, they may be inclined at the same angle, and the crossing angle between the first thrusting surface 52a and the second thrusting surface 52b may be an obtuse angle or an acute angle.

On the other hand, the locating portion 51 is formed in a convex shape having a first locating surface 51a and a second locating surface 51b that can be fitted to the first locating surface 52a and the second locating surface 52b.

In this way, the locating portion 51 and the locating portion 52 directly fit or abut each other and mate. However, the shapes of the recesses and projections of the stopper portion 51 and the thrust receiving portion 52 are not limited to the above-described shapes, and the positional regulation (positioning) of the first half body 10 and the second half body 20 can be achieved by fitting. ) are possible, other shapes such as related shapes such as semi-cylinders and semi-circular grooves are also possible. Further, since the fitting state of the stop portion 51 and the thrust receiving portion 52 is a relative relationship, the thrust receiving portion 52 is provided on the first half-split body 10 (locking block 14 ) side, and the stop portion 51 may be provided on the second half-split body 20 (locking holder 25) side.

Furthermore, the fuel holder 1 preferably has both the abutting means 5 and the locating means 50 as the first and second position regulating means 5, 50, but even if only one of them is provided, , the locking workability of the locking means 4 can be improved.

By housing the fuel assembly in such a fuel holder 1, the locking or releasing operation of the locking means 4 is facilitated. In addition, by mounting the fuel holder 1 containing the fuel assembly in the rectangular logiment hole 101 provided in the transport container 100 and transporting the fuel assembly, the outer surface of the fuel holder 1 and the inner surface of the logiment hole 101 are transported. without contact marks or scratches.

Furthermore, in order to maintain the performance of the transportation container 100, there is no need to check the condition of damage to the logiment hole 101 and repair or replace it as necessary. Moreover, since the fuel holder 1 is urged against the inner surface of the logiment hole 101 by the upper guide 80 and the lower roller 60 during transportation, it is possible to prevent the fuel holder from being displaced due to vibrations or the like, thereby preventing the surface from being damaged. .

As described above, the fuel holder 1 according to the embodiment of the present invention includes the first half 10 and the second half 20 having the two orthogonal wall portions 11, 12, 21, 22, and the top portion 30. and a bottom portion 40 forming a housing space for housing the fuel assembly, a connecting means 3 for connecting the first half 10 and the second half 20 so as to be openable and closable, a first A fuel holder 1 comprising a locking means 4 that locks the half-segmented body 10 and the second half-segmented body 20 so that they cannot be opened when the half-segmented body 10 and the second half-segmented body 20 are closed, wherein the first half-segmented body 10 and the second half-segmented body 20 are closed. It further comprises position regulating means 5 and 50 for regulating the positions of each other. As a result, when the first half-split body 10 and the second half-split body 20 are closed, the latching means 4 is present at an appropriate position as designed, thereby facilitating the latching operation. It should be noted that facilitating the locking work of the locking means 4 also leads to facilitating the releasing work of the locking means 4 .

The position regulating means 5 of the embodiment is an abutment portion 15 provided on the inner surface of the wall surface portion 22 of the second half-split body 20. abuts directly on the inner surface of the As a result, the position of the engaging means 4 in the opening/closing direction of the first half-split body 10 can be regulated only by pressing the first half-split body 10 .

The position regulating means 50 of the embodiment is the connecting means among the end sides 11a, 12a, 21a, and 22a of the two wall portions 11, 12, 21, and 22 of the first half-split body 10 and the second half-split body 20. 3, which are provided on the free sides 12a and 22a not connected by 3, and the stopping portion 51 and the thrusting portion 52 are in direct contact with each other. Thereby, the position can be regulated in the vicinity of the locking means 4 . In addition, the position of the locking means 4 in the direction intersecting (or substantially perpendicular to) the opening/closing direction of the first half-split body 10 can be regulated.

The locking pin 24 of the embodiment is formed in a tapered conical shape at the tip on the side of the locking block 14 . Thereby, even if the position of the locking means 4 is somewhat inappropriate, it can be guided to an appropriate position.

The locking pin 24 of the embodiment has a tapered conical tip on the opposite side that does not face the locking block 14 . As a result, even if the fuel holder 1 itself is deformed after use of the fuel holder 1 and the locking means 4 is out of position, the locking means 4 can be easily released.

In the embodiment, at least one of the connecting means 3 and the locking means 4 is provided so as not to protrude from the outer surface of the housing shell 2 . As a result, the only parts protruding from the fuel holder 1 (container shell 2) are the upper guide 80 and the lower roller 60, so damage due to contact of parts other than these with the inner surface of the logiment hole 101 can be prevented. can be done. If both the connecting means 3 and the locking means 4 are provided so as not to protrude from the outer surface of the housing shell 2, the parts protruding from the fuel holder 1 can be further reduced.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications, Change is possible.

1 fuel holder 2 housing shell 3 connecting means (hinge)
4 Locking Means 5 Position Regulating Means (Abutting Means)
10 first half-split body 11, 12 wall surface portion 11a end side (fixed side) 12a end side (free side) 14 locking block 14a locking hole 14a1 first tapered hole 14a2 second tapered hole 14a3 straight hole 14a4 prepared hole 15 abutment portion 15b contact surface 20 second half-split body 21, 22 wall surface portion 21a end side (fixed side) 22a end side (free side) 22b contact surface , 24 locking pin 24f front end taper portion 24r rear end taper portion 24s front end 25 locking holder 25a hole 26 operation means 27 elastic member 28, 28a, 28b, 28c groove 30 top portion 40 bottom portion 50 position Regulatory measures (finding measures)
51 locating portion, 51a first locating surface, 51b second locating surface, 52 abutting portion, 52a first abutting surface, 52b second abutting surface,
60 lower roller 70 heat radiation window 80 upper guide 100 transportation container, 101 logiment hole

Claims (6)

a first half-split body and a second half-split body having two wall surfaces perpendicular to each other, a housing shell having a top portion and a bottom portion forming a housing space for housing the fuel assembly;
connecting means for connecting the first half and the second half so that they can be opened and closed;
a locking means that locks the first half and the second half so that they cannot be opened when the first half and the second half are closed,
further comprising a position regulating means for regulating the positions of the first half and the second half when closed ;
The position restricting means is an abutment provided on a free side of the two wall surface portions of the first half and the second half that is not connected by the connecting means. is a part or a locating part,
The thrust receiving portion is formed in a concave shape and provided on one of the first half-split body and the second half-split body,
The stop portion is formed in a convex shape that can be fitted to the thrust receiving portion, and is provided on the other of the first half-split body and the second half-split body,
the abutment and the abutment directly abut each other;
A fuel holder characterized by: The locking means includes a retractable locking pin and a locking hole into which the locking pin is inserted,
the locking pin is inserted into a hole of a locking holder attached to one of the first half or the second half;
The locking hole is formed in a locking block attached to the other of the first half and the second half.
The fuel holder according to claim 1, characterized in that: The locking pin has a tapered conical tip on the opposite side that does not face the locking block,
3. The fuel holder according to claim 2, characterized in that: a first half-split body and a second half-split body having two wall surfaces perpendicular to each other, a housing shell having a top portion and a bottom portion forming a housing space for housing the fuel assembly;
connecting means for connecting the first half and the second half so that they can be opened and closed;
a locking means that locks the first half and the second half so that they cannot be opened when the first half and the second half are closed,
The locking means includes a retractable locking pin and a locking hole into which the locking pin is inserted,
the locking hole is formed in a locking block attached to the other of the first half and the second half;
The locking pin is inserted into a hole of a locking holder attached to one of the first half-split body and the second half-split body. formed as a tapered conical rear end taper ,
The locking pin is provided with an operation means for operating the locking pin,
The locking holder is provided with a groove for guiding the operating means,
The locking pin is formed to have a length such that the rear side of the rear end tapered portion is not exposed from the groove when the locking pin is locked in the locking hole.
A fuel holder characterized by: The locking pin has a tapered conical tip on the locking block side,
5. Fuel holder according to any one of claims 2 to 4, characterized in that: At least one of the connecting means and the locking means is provided so as not to protrude from the outer surface of the housing shell.
6. Fuel holder according to any one of claims 1 to 5, characterized in that:

Images