JP2017114564A - Buffer for transport container and cask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide buffer for a transport container which has high cushioning performance at a low cost, and a cask.SOLUTION: A buffer 10 for a transport container, which is mounted on a transport container 12 which can accommodate an object to be transported, comprises a casing 16 having an internal space, and an impact absorption member 20 which is charged in the internal space. The impact absorption member 20 is formed in such a manner that plural hollow cylindrical bodies 22, which are configured from a wall body in which plural fiber-reinforced plastic sheets are laminated, are arranged in parallel via a flexure allowable space.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a transport container buffer and a cask including the transport container buffer.

At the end of the nuclear fuel cycle, the nuclear fuel assembly that has been burned and can no longer be used, i.e., spent nuclear fuel contains highly radioactive material, so it is cooled for a specified period in the cooling pit of a nuclear power plant and then stored in a cask. , Transported to a reprocessing facility or spent fuel storage facility, etc. by truck or ship and stored.
When the spent nuclear fuel assemblies are accommodated in the cask, they are accommodated in a lattice-like structure called a basket. That is, it can be inserted into a plurality of storage spaces formed in the basket and can exhibit an appropriate holding force against vibration during transportation.

The cask has a cylindrical shape, and is provided with cushioning bodies at the upper part and the lower part in order to mitigate impacts such as when dropped. Conventionally, the buffer body used is a steel casing filled with wood as an impact absorbing member (see, for example, Patent Document 1).
Patent Document 2 discloses a configuration of a buffer body in which a hollow sphere made of metal or synthetic resin is filled inside a steel casing.

JP 2006090753 A JP 2000-168839 A

The cask and its buffer body are in a high temperature state due to the decay heat of the spent nuclear fuel when the spent nuclear fuel is stored.
The cask buffer body is required to withstand a high temperature environment and to exhibit a stable buffer performance in any dropping posture. The cask has an open / close lid for storing radioactive material. In order to prevent leakage of the radioactive material from the open / close lid, it is necessary to suppress the impact applied to the cask when it is dropped.
In the shock absorber filled with wood, there is a problem that the strength of the wood is dependent on temperature (strength reduction at high temperature), which leads to complication and enlargement of the shock absorber, leading to an increase in weight. In addition, since the strength is uniquely determined by the type of wood, there is no degree of design freedom and quality cannot be controlled artificially, so it must be a marginal design that takes into account variations in quality. However, an increase in size and weight is inevitable.
The buffer disclosed in Patent Document 2 has a problem that it is not easy to manufacture a hollow sphere having a high buffer performance and the cost is high.

  In view of the above problems, at least one embodiment of the present invention aims to realize a shock absorber for a transport container that has low cost and high buffer performance.

(1) A shock absorber for a transport container according to at least one embodiment of the present invention comprises:
A transport container buffer mounted on a transport container capable of accommodating a transported object,
A casing having an internal space;
An impact absorbing member filled in the internal space;
With
The impact absorbing member is formed by arranging a plurality of hollow cylindrical bodies composed of a wall body formed by laminating a plurality of fiber-reinforced plastic sheets in parallel with each other through a bending allowable space.

Here, the hollow cylindrical body includes all cylindrical structures having an internal space, and particularly includes a structure in which a slit, a hole, or the like is formed in a part of the wall.
According to the configuration (1), when an impact (load) is applied to the hollow cylindrical bodies arranged in parallel, the plurality of fiber reinforced plastics that constitute the wall body of the hollow cylindrical body by the bending of the hollow cylindrical body. Peeling breakage occurs between sheets of a manufactured sheet (hereinafter also referred to as “FRP sheet”). Since the impact is absorbed in the process of peeling and breaking, the impact on the transport container can be reduced.
Also, since wood is not used, the buffer performance degradation at high temperatures, which is a problem with wood, can be resolved, and FRP sheets are industrial products, and variation in quality can be controlled, minimizing tolerance design. As a result, the buffer can be reduced in size and cost.
Further, the compressive strength of the hollow cylindrical body can be controlled by changing the number of FRP sheets stacked and the outer diameter of the hollow cylindrical body. For example, if the number of layers is increased, the strength is increased, and if the outer diameter is increased, the strength is decreased. This makes it easier to optimally arrange the shock absorbers according to the specifications of the transport container and the additional load compared to wood.

(2) In some embodiments, in the configuration (1),
The plurality of hollow cylindrical bodies are arranged such that the axial direction is substantially perpendicular to at least one of the outer surfaces of the casing that do not face the transport container.
When a load is applied from the axial direction to the hollow cylindrical bodies arranged in parallel via the allowable bending space, the hollow cylindrical body absorbs the load due to the axial contraction and bends in the direction intersecting the axial direction. Mu This bending causes peeling failure between the FRP sheets, and absorbs the load in the process of peeling failure.
According to the configuration (2), since at least one of the loads in a plurality of directions applied to the transport container when the transport container is dropped is applied to the hollow cylindrical body from the axial direction, the impact absorbing effect of the hollow cylindrical body is achieved. Can be maximized.

(3) In some embodiments, in the configuration (1) or (2),
The plurality of hollow cylindrical bodies are:
A first group arranged along a first direction;
A second group arranged along a second direction intersecting the first direction;
including.
When the transport container is overturned or dropped, a load in a plurality of directions, not necessarily a one-way load, is applied to the shock absorber due to a drop posture or the like. Moreover, the direction and magnitude | size of the load added depend on the site | part of a buffer body.
According to the said structure (3), the load added to a transport container is arrange | positioned of a hollow cylindrical body by arrange | positioning the axial direction of a hollow cylindrical body in a different direction by the said 1st group and the said 2nd group. The probability of adding in the axial direction is increased, and thereby, the impact absorbing performance of the hollow cylindrical body can be surely exhibited.
In the configuration (3), it is not excluded to provide a third group having an axial direction different from that of the hollow cylindrical bodies of the first group and the second group.

(4) In some embodiments, in the configuration (3),
The transport container has a substantially cylindrical shape,
The casing has a recess that can be fitted into an end of the transport container,
The first group is the hollow cylindrical body arranged so that an axial end face thereof faces the substantially cylindrical end face,
The second group is the hollow cylindrical body arranged such that an axial end surface faces the substantially cylindrical peripheral surface.
There is a high probability that the impact of the transport container in the axial direction will be applied when it falls, etc. at the part of the shock absorber that faces the axial end surface of the transport container. There is a high probability that a radial impact (load) of the transport container is applied.
According to the configuration (4), the shock absorbing performance can be reliably exhibited by arranging the hollow cylindrical body in accordance with the direction of the impact having a high probability of being added.

(5) In some embodiments, in any of the methods (1) to (4),
The hollow cylindrical body has a pipe shape in which the wall body is formed over the entire circumference.
Here, the “pipe shape in which the wall body is formed over the entire circumference in the circumferential direction” refers to a cylindrical structure having no slits or holes in the wall body (partition wall).
According to the above configuration (5), since the hollow cylindrical body has the above configuration, peeling failure occurs between the FRP sheets over the entire circumference of the hollow cylindrical body, so that the impact absorption effect can be further enhanced. .

(6) In some embodiments, in any of the methods (1) to (5),
The hollow cylindrical body is configured by combining a plurality of plate-like members arranged in a direction in which the wall bodies intersect each other.
For example, the rectangular plate-like member is formed by providing cut portions with a constant interval on both edges, and alternately stacking the plate-like members so as to insert the cut portions into each other.
According to the said structure (6), a hollow cylindrical body can be manufactured at low cost.

(7) In some embodiments, in any one of the configurations (1) to (6),
It further includes a filler made of wood or foam filled in the hollow cylindrical body or at least one of the deflection-permitting spaces.
According to the said structure (7), adjustment of the rigidity of a hollow cylindrical body and the bending degree is attained by filling the inside of a hollow cylindrical body, or the filling allowance comprised by the wood or the foaming material. Thus, the rigidity and shock absorbing performance of the shock absorber can be adjusted to optimum conditions suitable for the use of the cask.
Moreover, the position of the hollow cylindrical body can be easily fixed by filling the bendable space with a filler made of wood or foam.

(8) In some embodiments, in the configuration (4),
A plurality of reinforcing ribs provided at intervals in the circumferential direction of the transport container on the inner surface of the recess of the casing;
The hollow cylindrical body is disposed between the plurality of reinforcing ribs.
According to the configuration (8), by providing the reinforcing rib, it is possible to prevent the buffer material from being displaced and slipped when a load is applied, and to sufficiently exhibit the shock absorbing performance of the buffer material.

(9) In some embodiments, in any one of the configurations (1) to (8),
The casing is made of a fiber reinforced plastic material.
According to the configuration (9), the buffer body can be further reduced in weight and strength.

(10) A cask according to some embodiments of the present invention includes:
A cylindrical transport container that contains radioactive material inside;
Any one of the above-described configurations (1) to (9);
Is provided.
According to the said structure (10), by providing the buffer body of said structure (1)-(9), the buffer performance fall at the time of the high temperature which is a subject of wood can be eliminated, and the variation in quality can be controlled. Therefore, it is possible to minimize the tolerance design, and thereby the buffer body can be reduced in size and cost.
Further, the impact absorbing performance can be enhanced by the bending of the hollow cylindrical body and the peeling failure occurring between the sheets of the FRP sheet.
In addition, by changing the number of FRP sheets stacked and the outer diameter of the hollow cylindrical body, it is possible to control the compressive strength of the hollow cylindrical body, which makes it easier to optimally place the shock absorber according to the applied load than wood. Become.

  According to at least one embodiment of the present invention, in a transport container, in particular, a cask buffer that contains a radioactive substance, it is possible to reduce the size and cost, and to improve the shock absorption performance when dropped.

It is a front view of a transportation container equipped with a shock absorber for transportation container according to an embodiment. It is front view sectional drawing of the shock absorber for transport containers which concerns on one Embodiment. It is sectional drawing which follows the AA line in FIG. It is front view sectional drawing of the shock absorber for transport containers which concerns on one Embodiment. It is a side view of the shock absorber for transportation containers concerning one embodiment. It is a perspective view of the hollow cylindrical body concerning one embodiment. It is a perspective view of the hollow cylindrical body concerning one embodiment. It is a diagram which shows the compressive strength of the hollow cylindrical body which concerns on one Embodiment. It is a diagram which shows the compressive strength of the hollow cylindrical body which concerns on one Embodiment. It is a diagram which shows the compressive strength of the hollow cylindrical body which concerns on one Embodiment. It is a perspective view of the hollow cylindrical body concerning one embodiment. It is a section side view of the impact-absorbing member concerning one embodiment. It is a section side view of the impact-absorbing member concerning one embodiment. It is explanatory drawing which shows another use of the shock absorber for transport containers which concerns on one Embodiment. It is explanatory drawing which shows the other use of the shock absorber for transport containers which concerns on one Embodiment.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of other constituent elements.

As shown in FIG. 1, the transport container cushion 10 according to some embodiments of the present invention is a buffer mounted on the transport container 12 that can accommodate the transport container 12.
In the exemplary embodiment, the transport container 12 includes a bottomed cylindrical transport container body 14 and an opening / closing lid 18 for taking in / out the transported object 15.
In the exemplary embodiment, the transport container 12 is a cask having a cylindrical outer shape that contains a radioactive material such as spent nuclear fuel as a transported object 15 therein.
In the illustrated embodiment, the transport container 12 is a cask having a cylindrical shape.
In FIG. 1, the arrow a direction indicates the axial direction of the transport container 12, and the arrow b direction indicates the radial direction of the transport container 12.

The shock absorber 10 includes a casing 16 that forms an outer shell, and the casing 16 has a recess 16 a into which an end of the transport container 12 is inserted. The casing 16 has an internal space s filled with the shock absorbing member 20.
As shown in FIGS. 2 to 4, the shock absorbing member 20 includes a large number of hollow cylindrical bodies 22 arranged in parallel.
The hollow cylindrical body 22 (22A, 22B, 22C) has a wall body formed by laminating a plurality of FRP sheets 24, as shown in FIGS. This is a hollow cylindrical structure having an internal space Si while being formed with an allowable bending space Sc between the hollow cylindrical bodies.
The hollow cylindrical body 22 includes all cylindrical structures having an internal space Si, and particularly includes a structure in which a slit, a hole, or the like is formed in a part of the wall body.

In the illustrated embodiment, as shown in FIG. 5, the shock absorber 10 has a circular outer shape, and a bolt hole 30 for attachment is formed in the casing 16.
In the exemplary embodiment, as shown in FIG. 6, the hollow cylindrical body 22 (22A) has a circular wall surface, and the hollow cylindrical body 22 (22B) shown in FIG. 7 has a rectangular wall surface.
The FRP sheet 24 is made of, for example, CFRP, GFRP, or the like. In addition, the FRP sheet 24 is, for example, arranged so that the fibers intersect in two directions to form a woven fabric.

  When an impact or a load is applied to the shock absorber 10 when the transport container 12 is overturned or dropped, the hollow cylindrical body 22 bends and causes a separation failure between the sheets of the FRP sheet 24. The impact on the transport container 12 can be mitigated by absorbing the impact.

The shock absorber 10 (10A, 10B) is applied with loads in a plurality of different directions depending on the posture at the time of dropping. Moreover, the direction and magnitude | size of the load added by the site | part of the buffer body 10 differ.
For example, as shown in FIGS. 2 and 4, a load Fa along the axial direction of the transport container 12 is applied to the end surface portion Pa facing the axial end surface of the transport container 12, and the peripheral surface facing the peripheral surface of the transport container 12. A load Fr along the radial direction of the transport container 12 is applied to the part Pr. Further, a load Ft oblique to the axial direction of the transport container 12 is applied to the corner portion Pt.

In the exemplary embodiment, the plurality of hollow cylindrical bodies 22 are arranged such that the axial direction is substantially perpendicular to at least one of the outer surfaces of the casing 16 that do not face the transport container 12. When the hollow cylindrical body 22 is arranged in this way, a load is applied from the axial direction to the plurality of hollow cylindrical bodies 22 arranged in parallel via the bending allowance space Sc, and the hollow cylindrical body 22 is in the axial direction. While absorbing the load by shrinkage, it bends in a direction crossing the axial direction. This bending causes peeling failure between the FRP sheets 24, and absorbs the load in the process of peeling failure.
By arranging the hollow cylindrical body 22 as described above, at least one of loads in a plurality of directions applied to the transport container 12 when the transport container 12 is dropped is applied to the hollow cylindrical body 22 from the axial direction. . Thereby, the impact absorbing effect of the hollow cylindrical body 22 can be maximized.

In the exemplary embodiment, the plurality of hollow cylindrical bodies 22 intersects the first group Pa arranged in the first direction and the first direction, as shown in FIGS. 2 and 4. And a second group Pr arranged along the second direction.
Thus, the axial direction of the hollow cylindrical body 22 is changed to the load applied to the transport container 12 by differently arranging the axial direction of the hollow cylindrical body 22 between the first group Pa and the second group Pr. The probability of being along is increased, and thereby, the impact absorbing performance of the hollow cylindrical body 22 can be reliably exhibited.

In the exemplary embodiment, as shown in FIG. 1, the transport container 12 has a substantially cylindrical shape, and the casing 16 has a recess 16 a into which the transport container 12 can be fitted at the axial end of the transport container 12.
The first group Pa is configured by a hollow cylindrical body arranged so that the axial end face thereof faces the axial end face of the transport container 12, and the second group Pr has an axial end face of the transport container 12. It is comprised with the hollow cylindrical body arrange | positioned so that a surrounding surface may be opposed.
As shown in FIGS. 2 and 4, there is a high probability that an axial load Fa of the transport container 12 is applied to the axial end surface of the transport container 12 when dropped, and the transport container 12 is disposed on the peripheral surface of the transport container 12. There is a high probability that a radial load Fr is applied.
Therefore, the axial direction of the hollow cylindrical bodies 22 of the first group Pa and the second group Pr is added by arranging the hollow cylindrical bodies 22 like the first group Pa and the second group Pr. The load Fa and Fr can be adjusted to ensure good shock absorption performance.

In addition, the hollow cylindrical body 22 provided in the corner | angular part Pt of the buffer body 10 (10A, 10B) is arrange | positioned suitably according to a condition.
In the illustrated embodiment, at the corner portion Pt of the shock absorber 10 (10A) shown in FIG. 2, the axial direction of the hollow cylindrical body 22 is arranged along the axial direction of the transport container 12, and the shock absorber shown in FIG. In the corner portion Pt of 10 (10B), the axial direction of the hollow cylindrical body 22 is arranged along the radial direction of the transport container 12. Moreover, the direction shown in FIG. 2 and the direction shown in FIG. 4 may be combined as the arrangement direction of the hollow cylindrical body provided in the corner portion Pt.

8 to 10 show the relationship between the compressive load F applied to the hollow cylindrical body 22 and the amount of peeling fracture δ in the axial direction of the hollow cylindrical body 22.
In FIG. 8, when the number of FRP sheets 24 stacked is increased, the compressive strength of the hollow cylindrical body 22 can be increased as shown by the broken line in the figure. On the other hand, when the outer diameter of the hollow cylindrical body 22 is increased, the compressive strength decreases.
Thus, the compressive strength of the hollow cylindrical body 22 can be controlled by changing the number of FRP sheets 24 stacked or the outer diameter of the hollow cylindrical body 22. The axial length of the hollow cylindrical body 22 is independent of the compressive strength.
Further, as shown in FIG. 8, for example, when the hollow cylindrical body 22 receives a compressive load F and the axial total length is 70 to 80% of the entire peel failure, the critical point C is set. Let the load F be Fo. The vertical axis indicates the compressive load F applied to the hollow cylindrical body 22, and this compressive load F is equivalent to the compressive strength of the hollow cylindrical body 22. The hollow cylindrical body 22 has a property that when the critical point C is passed, the compressive strength increases rapidly and does not shrink further in the axial direction. In FIG. 8, the hatched area E indicates the amount of impact energy that can be absorbed by the peeling fracture of the hollow cylindrical body 22.

As shown in FIG. 9, when the peel fracture amount δ of the hollow cylindrical body 22 is small with respect to the compression load F, that is, when the compressive strength of the hollow cylindrical body 22 is large, the amount of impact energy E ₁ that can be absorbed is Although it is large, a large load is applied to the transport container 12 accordingly. Therefore, the transport container 12 is required to have high durability.
On the other hand, as shown in FIG. 10, when the peel fracture amount δ of the hollow cylindrical body 22 is large with respect to the compressive load F, that is, when the compressive strength of the hollow cylindrical body 22 is small, it is added to the transport container 12. load is reduced, but the hollow cylindrical body 22 can absorb impact energy amount E ₂ is reduced. Therefore, in order to absorb the impact energy amount E ₁ equivalent impact energy amounts, it is necessary to increase the peeling fracture of the hollow cylindrical body 22 [delta].

Thus, depending on the design conditions such as the crushing allowance of the shock absorber 10, the load receiving area of the shock absorber 10, the weight of the transport container 12, the drop height of the transport container 12, the drop posture of the transport container 12, etc. By setting the compressive strength of the body 22 and disposing it on the shock absorber 10, the impact or load applied to the transport container 12 can be efficiently reduced.
For example, when a space during transportation such as a truck or a ship is large, in the axial direction of the transport container 12, a hollow cylindrical body 22 having a low compressive strength is provided in the first group Pa, and the hollow cylindrical body 22 is peeled off in the axial direction. By increasing the amount of destruction, the load applied to the transport container 12 can be reduced. On the other hand, when the space during transportation such as a truck or a ship is small, in the radial direction of the transport container 12, a hollow cylindrical body 22 having a high compressive strength is provided in the second group Pr, and the hollow cylindrical body 22 is peeled in the axial direction. Try to reduce the amount of destruction.

In the exemplary embodiment, as shown in FIG. 3, the hollow cylindrical body 22 has a pipe shape in which wall bodies (partition walls) are formed over the entire circumference.
In the present embodiment, the hollow cylindrical body 22 is a hollow cylindrical structure having no slits or holes in the wall body (partition wall) 22a, and the wall body 22a is continuous around the inner space Si. Has a surface.
Thereby, peeling failure between the FRP sheets can be caused on the entire circumference of the hollow cylindrical body 22, and the impact absorption effect can be further enhanced.

In the exemplary embodiment, as shown in FIG. 11, the hollow cylindrical body 22 (22C) is composed of a plurality of plate-like members 26 and 28 arranged in a direction in which the wall bodies intersect each other. The plate-like members 26 and 28 are configured by laminating a plurality of FRP sheets 24.
In the illustrated embodiment, notches 26 a and 28 a are provided at regular intervals on both edges of two rectangular flat plate members 26 and 28. And the hollow cylindrical body 22 is comprised by inserting the notch parts 26a and 28a mutually and laminating | stacking the plate-shaped members 26 and 28 alternately orthogonally.
Thereby, a hollow cylindrical body can be manufactured at low cost.

In the exemplary embodiment, in the cushioning body 10 (10C) shown in FIG. 12, at least one of the internal space Si and the bending-acceptable space Sc of the hollow cylindrical body 22 is filled with a filling 32 made of wood or foam material. To do.
In the exemplary embodiment, in the shock absorber 10 (10D) illustrated in FIG. 13, the bendable space Sc is filled with a filler 32 such as a foam material.
Thus, by filling the filler 32, the rigidity and the degree of deflection of the hollow cylindrical body 22 can be adjusted, and the rigidity and shock absorption performance of the shock absorber 10 are optimal for the use of the transport container 12. Can be adjusted to the conditions.
In the illustrated embodiment, the filler 32 is disposed over the entire axial length of the hollow cylindrical body 22 in the internal space Si or the deflection allowable space Sc of the hollow cylindrical body 22. By changing the filling rate in the axial direction of the filler 32 in the internal space Si of the hollow cylindrical body 22 or the bending allowable space Sc, the rigidity and shock absorbing performance of the buffer body 10 can be adjusted.

In the exemplary embodiment, as shown in FIG. 3, a plurality of reinforcing ribs 34 are provided on the inner surface of the recess 16 a of the casing 16 at intervals in the circumferential direction of the transport container 12. A shaped body 22 is arranged. Thus, the hollow cylindrical bodies 22 and the reinforcing ribs 34 are alternately arranged in the circumferential direction on the inner surface of the recess 16a.
By providing the reinforcing ribs 34, it is possible to prevent displacement and slipping of the shock absorber 22 when a load is applied, and the shock absorbing performance of the shock absorber 22 can be sufficiently exhibited.

  In the exemplary embodiment, casing 16 is comprised of a fiber reinforced plastic material. Thereby, the buffer body 10 can be further reduced in weight and strength.

According to some embodiments, when an impact (load) is applied to the shock absorber 10 when the transport container 12 is overturned or dropped, the FRP sheet 24 is peeled between the sheets due to the bending of the hollow cylindrical body 22. Since the breakage occurs and the shock is absorbed in the process of the peeling breakage, the shock to the transport container 12 can be reduced.
In addition, because wood is not used, the buffer performance degradation at high temperatures, which is a problem with wood, can be resolved, and variation in quality can be controlled, so that tolerance design can be minimized, The buffer body can be reduced in size and cost.
Further, the compression strength of the hollow cylindrical body 22 can be controlled by changing the number of the FRP sheets 24 stacked and the outer diameter of the hollow cylindrical body, whereby the buffer body 10 according to the specifications of the transport container 12 and the additional load. This makes it easier to place the unit than wood.

  According to the exemplary embodiment, as shown in FIGS. 2 and 4, the hollow cylindrical body 22 is divided into two groups, ie, a first group Pa and a second group Pr, which are different in the axial direction. Since the axial direction of the cylindrical body 22 is arranged along the direction of the load applied to the hollow cylindrical body 22, when the load is applied in the axial direction of the hollow cylindrical body 22, the hollow cylindrical body 22 is moved in the axial direction. It shrinks and bends in a direction that intersects the axial direction. Due to this bending, delamination breakage between the FRP sheets 24 occurs, and the impact is absorbed in the process of delamination breakage, so that the shock absorbing performance can be improved.

According to an exemplary embodiment, as shown in FIGS. 2 and 4, depending on the direction of two or more loads Fa, Fr and Ft in different directions assumed to be applied to the hollow cylindrical body 22, the hollow cylinder Since two or more parts Pa, Pr, and Pt having different axial directions of the cylindrical body 22 are provided, the axial direction of the hollow cylindrical body 22 can always be matched to the load direction at each part.
According to an exemplary embodiment, as shown in FIGS. 2 and 4, depending on the direction of two or more loads Fa, Fr and Ft in different directions assumed to be applied to the hollow cylindrical body 22, the hollow cylinder Since two or more groups Pa, Pr, and Pt having different axial directions of the cylindrical body 22 are provided, the axial direction of the hollow cylindrical body 22 can be matched to the load direction at each part of the buffer body 10.
Therefore, it is possible to reliably exhibit the impact absorption effect due to the peeling failure of the FRP sheet 24 in response to various falling and falling postures of the transport container 12.

According to the exemplary embodiment, the hollow cylindrical body 22 has a pipe shape in which the wall body 22a is formed over the entire circumference in the circumferential direction. And the impact absorbing effect can be further enhanced.
According to an exemplary embodiment, as shown in FIG. 11, the hollow cylindrical body 22 (22C) is manufactured using two rectangular plate-like members 26 and 28 arranged so as to cross each other. Therefore, it can be manufactured at a low cost.

  According to the exemplary embodiment, as shown in FIGS. 12 and 13, at least one of the internal space Si and the bending-allowable space Sc of the hollow cylindrical body 22 is filled with a filler 32 made of wood or foam material. By doing so, it becomes possible to adjust the rigidity and the degree of flexure of the hollow cylindrical body 22, and the rigidity and shock absorbing performance of the buffer body 10 can be adjusted to optimum conditions suitable for the use of the transport container 12.

According to the exemplary embodiment, as shown in FIG. 3, the hollow cylindrical body 22 and the reinforcing ribs 34 are alternately arranged in the circumferential direction on the inner surface of the recess 16 a of the casing 16, so that a load can be applied. Positional displacement and slipping of the shock absorber 22 can be prevented, and the shock absorbing performance of the shock absorber 22 can be fully exhibited.
According to the exemplary embodiment, the shock absorber 10 can be further reduced in weight and strength by configuring the casing 16 with a fiber reinforced plastic material.
According to the exemplary embodiment, the shock absorber 10 is applied to the cask containing the radioactive material as the transported object 15, so that the impact or load applied to the cask can be surely mitigated and the leakage of the radioactive material can be prevented. Therefore, it is possible to reduce the size and cost of the buffer.

FIG. 14 shows another application of the shock absorber 10. In FIG. 14, in the cask pit 42 provided in the spent fuel pool 40 in which the cooling water w is stored, there is a state in which the cask 44 is lifted or hung by the crane 46.
The buffer body 10 is provided on the floor surface 40 a below the cask 44. The buffer body 10 is disposed at a position where the cask 44 is assumed to fall. The arrows illustrated in the buffer body 10 indicate the axial direction of the hollow cylindrical body 22 provided in the buffer body 10.
Thus, by disposing the shock absorber 10 at the position where the cask 44 is dropped, the impact at the time of dropping can be efficiently reduced, and damage to the cask 44 and the cask pit floor can be suppressed.

FIG. 15 shows still another application of the shock absorber 10. In FIG. 15, the cask 44 is suspended by a crane 46 on a building 48 for storage or performing some processing on the cask 44.
The shock absorber 10 is disposed on the floor surface 48 a below the moving path of the cask 44 suspended from the crane 46. The shock absorber 10 is also provided on the inner wall 48b where the cask 44 moving with the crane 46 may collide.
By disposing the shock absorber 10 in the above position, even if the cask 44 falls and hits the floor surface 48a or the inner wall 48b, the impact on the cask 44, the floor surface 48a and the inner wall 48b can be reduced. Breakage of the floor surface 48a and the inner side wall 48b can be suppressed.

  According to at least one embodiment of the present invention, a shock absorber for a transport container having a low cost and high buffer performance can be realized, and is particularly suitable for a cask containing a radioactive substance.

10 (10A, 10B, 10C, 10D) Buffer 12 Transport container 14 Transport container body 15 Transported object 16 Casing 16a Recess 18 Opening / closing lid 20 Shock absorbing member 22 (22A, 22B, 22C) Hollow cylindrical body 22a Wall body 24 FRP sheet 26, 28 Plate-like members 26a, 28a Notch 30 Bolt hole 32 Filling 34 Reinforcement rib 40 Spent fuel pool 40a Floor surface 42 Cask pit 44 Cask 46 Crane 48 Building 48a Floor surface 48b Inner side wall C Critical point E , E ₁ , E ₂ Impact energy amount F, Fo Compressive load Fa, Fr, Ft load Pa End surface region Pr Peripheral surface region Pt Corner portion Sc Deflection allowable space Si, s Internal space δ Deformation amount

Claims (10)

A transport container buffer mounted on a transport container capable of accommodating a transported object,
A casing having an internal space;
An impact absorbing member filled in the internal space;
With
The impact absorbing member is formed by arranging a plurality of hollow cylindrical bodies composed of a wall body formed by laminating a plurality of fiber reinforced plastic sheets in parallel with each other through a bending allowable space. Transport container buffer.   The plurality of hollow cylindrical bodies are arranged such that an axial direction thereof is substantially perpendicular to at least one of the outer surfaces of the casing that do not face the transport container. The shock absorber for a transport container according to 1. The plurality of hollow cylindrical bodies are:
A first group arranged along a first direction;
A second group arranged along a second direction intersecting the first direction;
The shock absorber for a transport container according to claim 1 or 2, characterized by comprising: The transport container has a substantially cylindrical shape,
The casing has a recess that can be fitted into an end of the transport container,
The first group is the hollow cylindrical body arranged so that an axial end face thereof faces the substantially cylindrical end face,
The said 2nd group is the said hollow cylindrical body arrange | positioned so that an axial end surface may oppose the said substantially cylindrical surrounding surface, The buffer for transport containers of Claim 3 characterized by the above-mentioned.   5. The transport container buffer according to claim 1, wherein the hollow cylindrical body has a pipe shape in which the wall body is formed over the entire circumference in the circumferential direction.   The transport according to any one of claims 1 to 5, wherein the hollow cylindrical body is configured by combining a plurality of plate-like members arranged in a direction in which the wall bodies intersect each other. Buffer for containers.   The filler according to any one of claims 1 to 6, further comprising a filler made of wood or foam filled in at least one of the inside of the hollow cylindrical body or the bending allowable space. Transport container buffer. A plurality of reinforcing ribs provided at intervals in the circumferential direction of the transport container on the inner surface of the recess of the casing;
The shock absorber for a transport container according to claim 4, wherein the hollow cylindrical body is disposed between the plurality of reinforcing ribs.   The shock absorber for a transport container according to any one of claims 1 to 8, wherein the casing is made of a fiber reinforced plastic material. A cylindrical transport container that contains radioactive material inside;
The buffer according to any one of claims 1 to 9,
A cask characterized by comprising:

Images