JP2018054558A - Spent fuel assembly storage method and storage container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spent fuel assembly storage method which enables a sufficient number of spent fuel assemblies with high heat values to be stored in a storage container and to provide a spent fuel assembly storage container suitable for the method.SOLUTION: In a spent fuel assembly storage method, a storage container has a partition member to partition an inside thereof into a plurality of compartments. In a selection process, at least one compartment section included in a second region surrounded by a first region is selected as a non-storage compartment section in which no spent fuel assembly is allowed to be stored. In a storage process, the spent fuel assemblies are stored in the compartments excluding the non-storage compartment.SELECTED DRAWING: Figure 5

Description

  The present disclosure relates to a storage method and a storage container for a spent fuel assembly that is stored in a storage container for transporting or storing a spent fuel assembly.

  The spent fuel assembly after being used in the nuclear power plant is stored in a storage pool in the nuclear facility for a certain period, and then used fuel assembly storage container (hereinafter referred to as “storage container”) such as a cask. And is transferred to a storage facility. In such a storage container, a basket is disposed inside a hollow main body, and a plurality of spaces for storing spent fuel assemblies are provided in a lattice shape. Spent fuel assemblies stored in storage containers vary from those with a low heat value to those with a high heat value, and specifications of the storage container (for example, the maximum operating temperature and all uses stored in the storage container) The total heat generation amount of the spent fuel assembly is stored.

  Due to the nature of the spent fuel assembly, which is radioactive waste, it is desirable to increase the number of storage in the storage container. In Patent Document 1, in order to meet such a requirement, the heat flow is suppressed in the vertical direction by providing heat storage suppression means for suppressing heat storage in the neutron shield provided inside the hollow body. Thus, a technique for increasing the number of storages is disclosed.

JP 2001-235583 A

  In recent years, with the development of nuclear facilities, spent fuel assemblies with large calorific value are increasing. Such a spent fuel assembly having a large calorific value has a smaller number of housings in the storage container than a spent fuel assembly having a small calorific value. Although the said patent document 1 shows one solution with respect to such a subject, since the new design which adds a heat storage suppression means is needed, a cost increase becomes a problem. In the technique of Patent Document 1, there is a possibility of increasing the number of storages, but further improvement is desired.

  At least some embodiments of the present invention have been made in view of the above-described circumstances, and when a spent fuel assembly having a high calorific value is stored in a storage container for a spent fuel assembly, a sufficient number of storage is provided. It is an object of the present invention to provide a method and a storage container for a spent fuel assembly that can be secured.

(1) A method of storing a spent fuel assembly according to at least one embodiment of the present invention includes:
A container body;
A partition member that partitions the interior of the container body into a plurality of partition parts;
With
The plurality of partition parts include a first region including the partition part adjacent to the inner wall of the container main body and a second region surrounded by the first region when viewed from the extending direction of the partition part. A spent fuel assembly storage method for storing a spent fuel assembly in a storage container, comprising:
A selection step of selecting at least one of the compartments included in the second region as a non-containment compartment where storage of the spent fuel assembly is prohibited;
A storage step of storing the spent fuel assembly with respect to the partition portion excluding the non-storage partition portion;
Is provided.

  According to the above method (1), when the spent fuel assembly is stored in the storage container, at least one partition is selected as a non-storage partition in the second region where the maximum temperature is likely to be distributed. Thereby, when the spent fuel assembly is stored in the remaining compartments, the maximum temperature inside the container can be effectively suppressed. As a result, it is possible to efficiently store spent fuel assemblies having a high calorific value in storage containers having equivalent specifications. That is, by implementing the storage method as described above, it is possible to store more spent fuel assemblies having a large calorific value in a storage container having a specific specification.

(2) In some embodiments, in the method of (1) above,
In the selection step, a first partition portion that is closest to a central portion of the container body among the plurality of partition portions is selected so as to be included in the non-storage partition portion.

  According to the method (2) above, when the spent fuel assembly is stored in the storage container by selecting the first partition portion closest to the center portion of the container body as the non-storage partition portion, The maximum temperature can be effectively suppressed.

(3) In some embodiments, in any one of the methods (1) or (2) above,
In the selection step, among the partition parts included in the second region, the partition part adjacent to the partition part in which the spent fuel assembly having the largest heat generation amount is stored is the non-storage partition part. Selected to be included.

  According to the method of (3) above, when the compartment where the spent fuel assembly having the highest calorific value among the spent fuel assemblies housed in the plurality of compartments is stored is known, The maximum temperature in the container main body can be effectively suppressed by selecting the partition portion adjacent to it as the non-storage partition portion.

(4) In some embodiments, in any one of the methods (1) to (3) above,
A heat transfer body inserting step of inserting a heat transfer body into the non-storage compartment so as to contact at least one of the inner wall of the storage container and the partition member is further provided.

  According to the above method (4), by inserting the heat transfer body into the non-storage compartment, it is possible to promote heat dissipation to the outside of the amount of heat of the spent fuel assembly stored in the surrounding compartment. As a result, the maximum temperature in the container body is more effectively suppressed, and more spent fuel assemblies can be stored.

(5) In some embodiments, in any one of the methods (1) to (4) above,
In the storing step, the spent fuel assembly having a higher calorific value than the spent fuel assembly housed in the partition part included in the first region is placed in the partition part included in the second region. Store.

  According to the method (5), the storage layout is constructed so that the spent fuel assembly having a high calorific value is surrounded by the spent fuel assembly having a low calorific value. Such a layout is effective because the inclination of the temperature peak at the center of the storage container becomes sharper and the amount of reduction in the maximum temperature when the non-storage section is set can be increased.

(6) A method for storing a spent fuel assembly according to at least one embodiment of the present invention includes:
A container body;
A method for storing a spent fuel assembly, wherein the spent fuel assembly is stored in a storage container comprising: a partition member that partitions the interior of the container body into a plurality of partition parts;
A selection step of selecting at least one of the plurality of compartments as a non-containment compartment where storage of the spent fuel assembly is prohibited;
A storing step of storing the spent fuel assembly in the partition section excluding the non-storage section;
Is provided.

  According to the method (6) above, at least one of the plurality of compartments is selected as a non-container compartment, and the spent fuel assembly is accommodated in the remaining compartments. That is, not only the second area but also the first area is included as a selection target of the non-storage compartment. Even in such a case, when the spent fuel assembly is stored in the compartments other than the non-contained compartment, the maximum temperature in the container body can be suppressed to some extent. As a result, a spent fuel assembly having a high calorific value can be efficiently stored in a storage container having equivalent specifications.

(7) A spent fuel assembly storage container according to at least one embodiment of the present invention comprises:
A container body;
A partition member that partitions the interior of the container body into a plurality of partition parts;
With
The plurality of partition parts include a first region including the partition part adjacent to the inner wall of the container main body and a second region surrounded by the first region when viewed from the extending direction of the partition part. ,
At least one of the compartments included in the second region is defined as a non-containment compartment where storage of spent fuel assemblies is prohibited.

  According to the configuration of (7) above, when the spent fuel assembly is stored in the storage container, at least one partition is defined as a non-storage partition in the second region where the maximum temperature is likely to be distributed. . Thereby, when the spent fuel assembly is stored in the remaining compartments, the maximum temperature inside the container is effectively suppressed. As a result, a spent fuel assembly having a high calorific value can be efficiently stored, and a storage container having a large number of storage can be realized.

(8) In some embodiments, in the configuration of (7) above,
The non-storage compartment includes a first compartment that is closest to the center of the container body among the plurality of compartments.

  According to the configuration of (8) above, when the spent fuel assembly is stored in the storage container by defining the first partition portion closest to the center of the container body as the non-storage partition portion, The maximum temperature can be effectively suppressed.

(9) In some embodiments, in any one of the above configurations (7) or (8),
It further includes a heat transfer body inserted into the non-storage compartment so as to contact at least one of the inner wall of the storage container and the partition member.

  According to the configuration of (9) above, the heat transfer body is provided in the non-housing compartment, so that the heat radiation of the spent fuel assembly housed in the surrounding compartment is promoted to the outside. . As a result, the maximum temperature in the container body is more effectively suppressed, and a storage container that can store more spent fuel assemblies can be realized.

(10) In some embodiments, in the configuration of (9) above,
The heat transfer body is
A heat transfer member;
A biasing member that biases the heat transfer member toward both sides of the inner wall of the storage container along the extending direction of the partition;
including.

  According to the configuration of (10) above, the amount of heat of the spent fuel assembly stored around the heat transfer member is transferred to the outside by urging the heat transfer member to the inner wall of the storage container by the urging member. Heat dissipation can be promoted.

(11) In some embodiments, in any one of the above configurations (9) or (10),
The heat transfer body is
A heat transfer member;
A biasing member that biases the heat transfer member toward two or more surfaces of the partition member along a direction perpendicular to the extending direction of the partition part;
including.

  According to the configuration of (11) above, by urging the heat transfer member to the partition member by the urging member, the heat quantity of the spent fuel assembly housed around the heat transfer member is radiated to the outside. Can promote.

(12) In some embodiments, in the above configuration (9) or (11),
The heat transfer body is formed of a material having a larger thermal expansion coefficient than the partition member.

According to the configuration of (12) above, the heat transfer body whose temperature has risen due to the storage of the spent fuel assembly expands, so that the heat transfer body expands to both sides of the inner wall of the storage container or to two or more surfaces of the partition member. Contact and the heat dissipation of the spent fuel assembly to the outside is promoted. In particular, the heat transfer body is made of a material having a larger thermal expansion coefficient than that of the partition member. When the heat transfer body expands, the heat transfer body projects to the outside from the partition member so as to extend to both sides of the inner wall of the storage container or the partition member 2. It can be in good contact with at least the surface and good thermal conductivity can be obtained.
In addition, since this structure does not include the member which deform | transforms mechanically like the above-mentioned biasing member, there is little influence of fatigue, aged deterioration, etc., and it is advantageous at the point which can exhibit stable performance over a long term.

(13) In some embodiments, in any one of the above configurations (9) to (12),
The heat transfer body includes a neutron absorber.

  According to the configuration of (13) above, the neutron shielding function or subcritical function of the storage container 1 can be effectively enhanced with a simple configuration. Further, by adopting such a heat transfer body, it is possible to easily improve the neutron shielding performance or subcritical performance in the existing storage container.

(14) In some embodiments, in any one of the above configurations (7) to (13),
In order to prohibit the storage of the spent fuel assembly in the non-storage compartment, a sealing member for sealing the non-storage compartment is further provided.

  According to the configuration (14), a user who is not familiar with the handling of the storage container may accidentally store the spent fuel assembly in the non-storage compartment, but a sealing member is provided. Thus, the insertion of the spent fuel assembly into the non-storage compartment is structurally prohibited, and such user-side mistakes can be prevented.

  According to at least one embodiment of the present invention, when a spent fuel assembly having a high calorific value is housed in a spent fuel assembly storage container, it is possible to store a spent fuel assembly capable of securing a sufficient number of houses. Methods and storage containers can be provided.

It is a perspective view of the spent fuel assembly accommodated in the spent fuel assembly storage container according to at least one embodiment of the present invention. It is a schematic diagram which shows the accommodation operation | work of the spent fuel assembly of FIG. It is a longitudinal cross-sectional view of the storage container of FIG. It is AA sectional drawing of FIG. It is a flowchart which shows the accommodation method of the spent fuel assembly which concerns on one Embodiment of this invention for every process. It is a schematic diagram which shows the example of a 1st area | region and 2nd area | region for the some division part shown by FIG. It is a schematic diagram which shows one of the examples of selection of the non-storage division part in step S3. It is a graph which shows the temperature distribution along the X direction of a container main body. It is a schematic diagram which shows the selection variation of the non-storage division part in FIG.5 S3. It is a schematic diagram which shows the other selection variation of the non-storage division part in step S3 of FIG. It is a schematic diagram which shows the other selection variation of the non-storage division part in step S3 of FIG. It is a schematic diagram which shows the other selection variation of the non-storage division part in step S3 of FIG. It is sectional drawing of the storage container in which the heat-transfer body 32 was inserted in the non-storage division part in FIG. It is a variation of the heat transfer body of FIG. It is a variation of the heat transfer body of FIG. It is sectional drawing which shows the structure which applied the sealing member to FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. 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. Absent.
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.
In addition, for example, expressions representing shapes such as quadrangular shapes and cylindrical shapes not only represent shapes such as quadrangular shapes and cylindrical shapes in a strict geometric sense, but also within the range where the same effect can be obtained. A shape including a chamfered portion 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 the other constituent elements.

  FIG. 1 is a perspective view of a spent fuel assembly 100 stored in a storage container 1 according to at least one embodiment of the present invention. The spent fuel assembly 100 is configured by bundling a plurality of spent fuel rods 101 formed in a longitudinal shape by a plurality of support grids 102. Nozzles 103 are arranged at both ends of the spent fuel rod 101, respectively.

  2 is a schematic view showing the storage operation of the spent fuel assembly 100 of FIG. 1, FIG. 3 is a longitudinal sectional view of the storage container 1 of FIG. 2, and FIG. 4 is a cross-sectional view of FIG. is there.

  The storage container 1 stores a plurality of spent fuel assemblies 100 taken out from the nuclear reactor, and is used for transportation and storage of the spent fuel assemblies 100. The storage container 1 includes a bottomed container body 2 having an open top, a neutron shield 18 attached to the outside of the container body 2, and a lid member (a primary lid 4 and a secondary lid for closing the opening 9 of the container body 2). A lid 6).

  As shown in FIG. 3, the container body 2 includes a cylindrical body portion 8 and a bottom portion 11 provided at the lower end of the body portion 8. The body portion 8 and the bottom portion 11 define a substantially cylindrical internal space (cavity) 12, and the spent fuel assembly 100 is accommodated in the internal space 12.

  In the hollow internal space 12, partition members (baskets) 20 are provided for defining a plurality of partition portions 22 in which spent fuel assemblies to be stored can be stored. The partition member 20 is configured by combining a plurality of square pipes, each having a rectangular shape (substantially square shape) in cross-sectional outer shape and inner cross-sectional shape, in combination with a metal plate on a flat plate. Thus, the internal space 12 is partitioned into a lattice shape, and a plurality of partition portions (cells) 22 are formed. Such a partition member 20 is configured so that individual spent fuel assemblies 100 are stored in the respective partition portions 22 by being disposed in the internal space 12.

  The plurality of partition portions 22 included in the partition member 20 have a substantially square shape in an XY plan view so as to correspond to the shape of the spent fuel assembly 100 to be stored. The size of each partition 22 is designed to be slightly larger than the spent fuel assembly 100 to be housed, and is configured to be smoothly inserted when housed. The number of the partition portions 22 included in the partition member 20 is appropriately set based on the design specifications of the storage container 1, the type of the spent fuel assembly, the storage environment of the storage container 1, and the like in the present embodiment. As shown, a partition member 20 having a total of 26 partition portions 22 is shown.

  The container body 2 has a function of shielding γ rays radiated outward from the spent fuel assembly 100 housed in the internal space 12. Further, the neutron shield 18 is provided with a neutron shield for shielding neutrons.

  In the internal space 12 of the container main body 2, a spacer 10 is disposed between the inner peripheral wall of the container main body 2 and the partition member 20. The spacer 10 transmits decay heat from the spent fuel assembly 100 stored in the partition member 20 to the container body 2. The decay heat is released to the outside through the container body 2 and the neutron shield 18.

Of the lid members, the primary lid 4 is attached to the upper opening 9 of the container body 2 after storing the spent fuel assembly 100 in the partition member 20 disposed in the internal space 12 of the container body 2. The secondary lid 6 is attached to the opening 9 of the container body 2 so as to cover the outside of the primary lid 4. Thereby, the internal space 12 of the container body 2 is sealed by the primary lid 4 and the secondary lid 6.
Depending on the specifications of the storage container 1, a tertiary lid that covers the outer side of the secondary lid 6 may be provided.

  Next, a method for storing the spent fuel assembly 100 in the storage container 1 having the above configuration will be described. FIG. 5 is a flowchart showing a method of storing the spent fuel assembly 100 according to an embodiment of the present invention for each process.

  First, an operator who implements the storage method specifies a plurality of compartments 22 included in the storage container 1 that is a storage target of the spent fuel assembly (step S1). In the example of FIGS. 3 and 4, a total of 26 partition portions 22 arranged in a lattice shape are specified as described above.

  Then, the 1st field 24 and the 2nd field 26 are specified for a plurality of division parts 22 specified at Step S1 (Step S2). Here, with reference to FIG. 6, the definition method of the 1st area | region 24 and the 2nd area | region 26 in step S2 is demonstrated concretely. FIG. 6 is a schematic diagram illustrating an example of defining the first region 24 and the second region 26 for the plurality of partition portions 22 illustrated in FIG. 4.

  The first region 24 is defined as a region adjacent to the body portion 8 of the container body 2 among the plurality of partition portions 22. On the other hand, the second region 26 is defined as a region surrounded by the first region 24 among the plurality of partition portions 22. That is, the second region 26 is defined as a set of partition portions 22 surrounded on the inner side from the first region 24 defined in a ring shape along the trunk portion 8.

  Returning to FIG. 3 again, the non-storage compartment 30 is subsequently selected from the second region 26 defined in step S2 (step S3). The non-storage compartment 30 is a compartment 22 where storage of the spent fuel assembly 100 that is a storage target is prohibited, and at least one of the compartments 22 included in the second region 26 is selected. FIG. 7 is a schematic diagram showing one example of selection of the non-storage compartment 30 in step S3. In this example, the partition part (first partition part) 22 closest to the central part C of the body part 8 (container body 2) among the plurality of partition parts 22 is selected as the non-storage compartment part 30.

  Then, the spent fuel assembly 100 is stored in the remaining compartments 22 excluding the non-storage compartment 30 selected in step S3 (step S4). In other words, the spent fuel assemblies 100 are not stored in all the compartments 22, but the non-storage compartments 30 are not stored with the spent fuel assemblies 100 and remain empty.

  In this way, the storage of the spent fuel assembly 100 in the storage container 1 is completed (end). In the storage container 1 that has been stored, the second area 26 includes the non-storage section 30 (that is, the area in which the spent fuel assembly 100 is not stored), so that the maximum temperature inside the storage container 1 is effective. Is suppressed. For example, when the spent fuel assemblies 100 having the same calorific value are stored in all the compartments 22, the temperature distribution is such that the temperature T <b> 1 is obtained at the center C of the storage container 1 as indicated by the broken line in FIG. 8. It becomes a peak. As described above, in the storage container 1, there is a tendency that a temperature distribution having the maximum temperature T1 is formed in the vicinity of the central portion C, and the specification of the storage container 1 is also defined based on the maximum temperature T1.

  In recent years, with the development of nuclear facilities, spent fuel assemblies with large calorific value are increasing. Conventionally, it has been desired to store more spent fuel assemblies having a high calorific value in a storage container 1 having a specific specification. At that time, keeping the internal temperature of the storage container 1 within the specification standard is one barrier, but in the second region 26 inside the first region 24 as described above, the non-storage compartment 30 (ie, By setting the region in which the spent fuel assembly 100 is not stored, the maximum temperature inside the storage container 1 is effectively suppressed. Specifically, as indicated by a solid line in FIG. 8, the maximum temperature T1 at the center C can be reduced to T2. As a result, since the margin of the maximum temperature is expanded, the spent fuel assembly 100 having a large calorific value can be stored in the storage container 1 having the same specification.

  In step S 4, the spent fuel assembly 100 having a higher calorific value than that of the compartment 22 included in the first region 24 is stored in the compartment 22 included in the second region 26. Good. That is, the storage layout is constructed so that the spent fuel assembly 100 having a high calorific value is surrounded by the spent fuel assembly 100 having a low calorific value. In such a layout, the slope of the peak of the temperature distribution shown in FIG. 8 becomes sharper, and the maximum temperature reduction amount (that is, the difference between the temperatures T1 and T2) when the non-storage compartment 30 is set is increased. Effective because it can be enlarged.

  By the way, in step S <b> 3, there are some variations in addition to FIG. 7 described above as to which of the partition sections 22 included in the second region 26 is selected as the non-storage partition section 30. 9 to 12 are schematic views showing selection variations of the non-storage compartment 30 in step S3 of FIG.

  The example of FIG. 9 is different from that of FIG. 7 in that the total number of the plurality of partition portions 22 is 52. In this case, the center part C of the container body 2 is located immediately above the partition member 20, and the partition part (first partition part) 22 closest to the center part C as shown in FIG. It is not possible (in other words, there are a plurality (four) of partition sections (first partition sections) 22 closest to the center C). In such a case, as shown in FIG. 9, all of the plurality (four) of partition sections 22 that are closest to the center portion C may be selected as the non-storage section 30. Alternatively, a part (one or a plurality) of the plurality (four) of the partition portions 22 closest to the center portion C may be selected as the non-storage partition portion 30.

In FIG. 10, the structure of the storage container 1 is the same as that in FIG. 7, but the compartment (second compartment) in which the spent fuel assembly 100 having the largest calorific value among the plurality of compartments 22 is stored in advance. The selection variation of the non-storage compartment 30 when 22 is known is shown. In this example, the spent fuel assembly 100 having the largest calorific value is stored in one of the partition portions 22 included in the second region 26. In this case, a partition part (third partition part) adjacent to the partition part (second partition part) 22 in the second region 26 is selected as the non-storage compartment part 30.
As described above, when the spent fuel assembly 100 having the largest calorific value among the spent fuel assemblies 100 to be stored is known, the partition portion 22 is selected as the non-storage partition portion 30. The maximum temperature in the container body 2 can be effectively suppressed.

  In FIG. 11, the structure of the storage container 1 is the same as that of FIG. 7, but is different in that a plurality of non-storage compartments 30 are selected. In this case, as in the case of FIG. 7, the non-storage compartment 30 is preferably selected as the compartment (first compartment) 22 closest to the center C and the compartment 22 adjacent thereto. More preferably, the partition part 22 diagonally adjacent to the partition part (first partition part) 22 may be selected as the non-storage compartment part 30. In this case, since the non-storage compartment 30 is adjacent to the spent fuel assembly 100 stored in the remaining compartment 22 from a plurality of directions, the maximum temperature in the storage container 1 can be more effectively suppressed. .

  In FIG. 12, the structure of the storage container 1 is the same as that of FIG. 7, but is different in that the selection target of the non-storage compartment 30 is the entire plurality of compartments 22. That is, in the above-described embodiment, only the second region 26 is selected from the plurality of partition portions 22 of the non-storage partition portion 30, but in this embodiment, from the first region 24 as shown in FIG. It may be selected.

  In the above-described embodiment, the spent fuel assembly 100 is not housed in the compartment 22 selected as the non-housing compartment 30 and is left empty, but the non-housing compartment 30 will be described below. The heat transfer body 32 may be inserted as described above (that is, in the storage method shown in FIG. 5, the heat transfer body 32 is inserted into at least one of the non-storage compartments 30 selected in step S3. It may further comprise a body insertion step).

  13 is a cross-sectional view of the storage container 1 in which the heat transfer body 32 is inserted into the non-storage compartment 30 in FIG. In this embodiment, the heat transfer body 32 is inserted into the partition portion 22 (first partition portion) located in the central portion C among the plurality of partition portions 22, and the spent fuel assembly is disposed in the remaining partition portions 22. 100 is stored. The heat transfer body 32 includes a first member 32a that contacts the primary lid 4 positioned on the upper side, a second member 32b that contacts the bottom 11 positioned on the lower side, and the first member 32a and the second member 32b. And an urging member (for example, a spring member) 32c provided so as to be interposed therebetween.

The first member 32a and the second member 32b are made of a material having excellent heat conductivity, and are metal bodies such as an aluminum alloy and a copper alloy. Moreover, the neutron absorber may be contained in the 1st member 32a and the 2nd member 32b. Thereby, the neutron shielding function or subcritical function of the storage container 1 can be effectively enhanced with a simple configuration. In addition, by adopting such a heat transfer body 32, the neutron shielding performance in the existing storage container 1 can be easily improved.
The first member 32a and the second member 32b may be hollow. In this case, the weight of the first member 32a and the second member 32b can be reduced, which is advantageous.

  The urging member (for example, a spring member) 32c is inserted between the first member 32a and the second member 32b in a reduced size from a neutral state in advance. Therefore, the biasing member 32 c elastically contacts the first member 32 a with the primary lid 4 and elastically contacts the second member 32 b with the bottom portion 11. Thereby, the contact state between the 1st member 32a and the primary cover 4 and the contact state between the 2nd member 32b and the bottom part 11 are maintained favorably.

  The heat transfer body 32 stored in the non-storage section 30 receives the amount of heat released from the spent fuel assembly 100 stored in the surrounding partition section 22. Since the heat transfer body 32 is in contact with the primary lid 4 and the bottom part 11 as described above, the amount of heat is transmitted to the outside through these. Due to the heat radiation action of the heat transfer body 32, the internal temperature of the storage container 1 is reduced, and the margin of the maximum temperature is expanded. As a result, the spent fuel assembly 100 having a large calorific value can be stored in the storage container 1 having the same specification.

  The shapes of the first member 32a and the second member 32b may be arbitrary, but preferably a wide contact area between the first member 32a and the primary lid 4 and a wide contact area between the second member 32b and the bottom portion 11 are secured. By doing so, the heat conductivity may be improved. In FIG. 13, a clearance is provided between the first member 32a and the second member 32b and the partition member 20 in order to smoothly insert the heat transfer body 32. As long as it does not become, heat conductivity may be made to improve because the side surface of the 1st member 32a and the 2nd member 32b contacts the partition member 20. FIG.

  The first member 32a and the second member 32b are made of a material having excellent heat conductivity, and are metal bodies such as an aluminum alloy and a copper alloy. Moreover, the neutron absorber may be contained in the 1st member 32a and the 2nd member 32b. Thereby, the neutron shielding function or subcritical function of the storage container 1 can be effectively enhanced with a simple configuration. Further, by adopting such a heat transfer body 32, it is possible to easily improve the neutron shielding performance or subcritical performance in the existing storage container 1.

  FIG. 14 is a modification of FIG. In this modification, as in FIG. 13, the heat transfer body 33 is provided so as to be interposed between the first member 33a, the second member 33b, and the first member 33a and the second member 33b. A member (for example, a spring member) 33c, the first member 33a and the second member 33b are disposed so as to contact the partition member 20, and the biasing member 33c includes the first member 33a and the second member 33b. The second member 33b is urged in a direction perpendicular to the extending direction of the partition portion 22. In this case, heat conductivity improves because the 1st member 33a and the 2nd member 33b contact the partition member 20. FIG.

  In addition, the 1st member 33a and the 2nd member 33b are comprised from the plate-shaped member which has a large contact area with the partition member 20, as FIG. 14 shows. And between the 1st member 33a and the 2nd member 33b, the several urging | biasing member 33c is arrange | positioned along the extension direction of the division part 22. As shown in FIG. Thereby, the 1st member 33a and the 2nd member 33b can be made to contact the partition member 20 with a uniform pressing force over a wide area | region.

  FIG. 15 shows a further variation of the heat transfer body 32. The heat transfer body 32d used in this embodiment includes a plurality of components (first member 32a, second member 32b and biasing member 32c, or first member 33a, first member as shown in FIGS. It is not composed of the two members 33b and the urging member 33c), but is an integral component and is made of a material having a high thermal expansion coefficient. The heat transfer body 32d is disposed in the non-housing compartment 30 with the lower end in contact with the bottom 11 and the upper end having a gap with the primary lid 4 at room temperature. When the spent fuel assembly 100 is stored in the surrounding partition section 22, the heat transfer body 32d expands by receiving the amount of heat released from the spent fuel assembly 100.

  Thereby, the upper end of the heat transfer body 32d is in contact with the primary lid 4 and the lower end is in contact with the bottom portion 11. As a result, the heat transfer body 32d releases the amount of heat from the spent fuel assembly 100 stored inside the storage container 1 to the outside through the primary lid 4 and the bottom portion 11. Due to the heat radiation action of the heat transfer body 32d, the internal temperature of the storage container 1 is reduced, and the margin of the maximum temperature is expanded. As a result, the spent fuel assembly 100 having a large calorific value can be stored in the storage container 1 having the same specification. In particular, the heat transfer body 32d is superior in that it can stably perform in the long term because it does not have a mechanically deformed configuration as compared with the heat transfer body 32 shown in FIGS. .

  Here, the heat transfer body 32d may be formed of a material having a higher thermal expansion coefficient than that of the partition member 20 disposed around the heat transfer body 32d. In this case, since the heat transfer body 32d has a larger coefficient of thermal expansion than the partition member 20, when the temperature rises, the heat transfer body 32d expands so as to protrude in the vertical direction as compared with the partition member 20, and the primary lid 4 and the bottom portion 11 are expanded. Each is pressed and a good heat dissipation effect is obtained.

  The heat transfer body 32d may also contain a neutron absorber. Thereby, the neutron shielding function or subcritical function of the storage container 1 can be effectively enhanced with a simple configuration. Further, by adopting such a heat transfer body 32d, it is possible to easily improve the neutron shielding performance or subcritical performance in the existing storage container 1.

  In each of the above-described embodiments, as shown in FIG. 16, the sealing member 36 is provided to structurally prohibit the insertion of the spent fuel assembly 100 into the compartment 22 selected as the non-storage compartment 30. It may be provided. As described above, since the non-storage compartment 30 has various selection variations, a user who is not familiar with the handling of the storage container 1 incorrectly stores the spent fuel assembly 100 in the non-storage compartment 30. There is a risk that. In the present embodiment, by providing the sealing member 36, the insertion of the spent fuel assembly 100 into the non-storage compartment 30 is structurally prohibited, and such user-side mistakes can be prevented.

  As described above, according to the above-described embodiment, when a spent fuel assembly having a high calorific value is stored in a storage container for a spent fuel assembly, a used fuel assembly that can secure a sufficient number of stored fuel assemblies. Storage method and storage container can be provided.

  At least 1 embodiment of this invention can be utilized for the storage method and storage container of the spent fuel assembly accommodated in the storage container for transporting or storing a spent fuel assembly.

DESCRIPTION OF SYMBOLS 1 Storage container 2 Container main body 4 Primary lid 6 Secondary lid 8 Trunk part 9 Opening 10 Spacer 11 Bottom part 12 Internal space 18 Neutron shielding body 20 Partition member 22 Partition part 24 1st area | region 26 2nd area | region 30 Non-accommodation compartment part 32, 32d, 33 Heat transfer bodies 32a, 33a First members 32b, 33b Second members 32c, 33c Energizing member 36 Sealing member 100 Spent fuel assembly 101 Spent fuel rod 102 Support grid 103 Nozzle

Claims (14)

A container body;
A partition member that partitions the interior of the container body into a plurality of partition parts;
With
The plurality of partition parts include a first region including the partition part adjacent to the inner wall of the container main body and a second region surrounded by the first region when viewed from the extending direction of the partition part. A spent fuel assembly storage method for storing a spent fuel assembly in a storage container, comprising:
A selection step of selecting at least one of the compartments included in the second region as a non-containment compartment where storage of the spent fuel assembly is prohibited;
A storage step of storing the spent fuel assembly with respect to the partition portion excluding the non-storage partition portion;
A method for storing a spent fuel assembly.   2. The used according to claim 1, wherein, in the selection step, a first partition portion that is closest to a central portion of the container main body is selected from the plurality of partition portions so as to be included in the non-storage compartment portion. How to store the fuel assembly.   In the selection step, among the partition parts included in the second region, the partition part adjacent to the partition part in which the spent fuel assembly having the largest heat generation amount is stored is the non-storage partition part. The method for storing spent fuel assemblies according to claim 1 or 2, which is selected to be included.   4. The heat transfer body insertion step of further inserting a heat transfer body into the non-storage section so as to contact at least one of the inner wall of the storage container and the partition member. 5. Storage method for spent fuel assemblies.   In the storing step, the spent fuel assembly having a higher calorific value than the spent fuel assembly housed in the partition part included in the first region is placed in the partition part included in the second region. The method for storing a spent fuel assembly according to any one of claims 1 to 4, wherein the storage is performed. A container body;
A method for storing a spent fuel assembly, wherein the spent fuel assembly is stored in a storage container comprising: a partition member that partitions the interior of the container body into a plurality of partition parts;
A selection step of selecting at least one of the plurality of compartments as a non-containment compartment where storage of the spent fuel assembly is prohibited;
A storing step of storing the spent fuel assembly in the partition section excluding the non-storage section;
A method for storing a spent fuel assembly. A container body;
A partition member that partitions the interior of the container body into a plurality of partition parts;
With
The plurality of partition parts include a first region including the partition part adjacent to the inner wall of the container main body and a second region surrounded by the first region when viewed from the extending direction of the partition part. ,
At least one of the compartments included in the second region is a spent fuel assembly storage container that is defined as a non-storage compartment that is prohibited from storing spent fuel assemblies.   The spent fuel assembly storage container according to claim 7, wherein the non-storage compartment includes a first compartment closest to a central portion of the container main body among the plurality of compartments.   The storage container for a spent fuel assembly according to claim 7 or 8, further comprising a heat transfer body inserted into the non-storage compartment so as to contact at least one of an inner wall of the storage container and the partition member. The heat transfer body is
A heat transfer member;
A biasing member that biases the heat transfer member toward both sides of the inner wall of the storage container along the extending direction of the partition;
The spent fuel assembly storage container according to claim 9, comprising: The heat transfer body is
A heat transfer member;
A biasing member that biases the heat transfer member toward two or more surfaces of the partition member along a direction perpendicular to the extending direction of the partition part;
The storage container for the spent fuel assembly according to claim 9 or 10, comprising:   The storage container for a spent fuel assembly according to claim 9 or 11, wherein the heat transfer body is formed of a material having a larger thermal expansion coefficient than the partition member.   The spent fuel assembly storage container according to any one of claims 9 to 12, wherein the heat transfer body includes a neutron absorber.   The sealing member according to any one of claims 7 to 13, further comprising a sealing member that seals the non-storage compartment in order to prohibit the storage of the spent fuel assembly in the non-storage compartment. Storage container for spent fuel assemblies.

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