JP2006105815A - Radioactive material container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower the temperature in the middle of a container body for radioactive material, which is formed by slushing and solidifying of neutron absorber material in a space formed between the container body and an outer cylinder, by bringing the surface of heat conduction fins that are in contact with both of the outer surface of the container body and the outer cylinder inner surface with a sufficient force to improve heat conduction performance. <P>SOLUTION: The radial dimension of the heat conducting fins 7, arranged inside the neutron absorber 8 is set higher than the inner surface of the outer cylinder 6, and the cross-sectional shape of the heat conduction fins 7 is made to bend with a low load, when the outer cylinder 6 is pushed during assembly so that the outside of the heat conduction fins 7 is made to contact the outer cylinder 6 inner surface to realize proper heat conduction performance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radioactive substance storage container for transporting or storing spent fuel generated from a nuclear power plant, and more particularly to a structure of a portion of a radioactive substance storage container filled with a neutron absorber (resin).

  The fuel used for a certain period in the core of the nuclear power generation facility is taken out from the core and temporarily stored in a spent fuel pool or the like. The fuel cooled for a predetermined period is finally carried to a reprocessing plant where it is reprocessed, uranium and plutonium are taken out, and used as resources.

  Currently, the amount of spent fuel generated at nuclear power plants is increasing as the demand for electricity increases. It must be properly managed and stored in the period until it is exceeded and reprocessed. The required storage is estimated to be 4400 tU in 2010 and 7100 tU in 2020.

  As a method of managing and storing spent fuel inside or outside the site of a nuclear power plant, there are dry storage methods such as dry cask storage, vault storage, silo storage, and concrete cask storage, and wet storage methods such as water pools. is there.

  In consideration of storage costs and long-term storage stability, dry storage systems are attracting attention. Among the dry storage systems, the cask storage system currently in practical use in Japan is a method of storing spent fuel in a dry cask that is a radioactive substance storage container.

  In a dry cask containing spent fuel, it is necessary to install a member that absorbs neutrons emitted from the spent fuel assembly on the outer periphery of the containing container.

  In addition, if the heat conductivity of the heat transfer member interposed between the storage container and the outer cylinder is poor, the temperature of the cladding tube of the stored spent fuel assembly will rise excessively, which may cause creep failure. From the viewpoint of structural strength, sufficient cooling performance is required.

  The structure of the radiation absorber that formed a space filled with neutron absorbers by attaching copper ribs extending diagonally in the radial direction with bolts to the outer surface of the storage container body, welding the ends of the copper ribs with a steel outer cylinder It has been proposed (see, for example, Patent Document 1).

  A resin body having a relatively large hydrogen atom-containing component is disposed in a space surrounded by the storage container main body, the outer tube, and the copper heat transfer fins, and a thermal expansion absorbing member is disposed along the inner surface of the outer tube. There has also been proposed a structure of a radiation absorber that fills a space between the resin body and a heat-resistant liquid resin and solidifies it to absorb the thermal expansion deformation of the neutron absorber (see, for example, Patent Document 2).

Japanese National Publication No. 9-512334 (pages 3-4) Japanese Patent Laid-Open No. 2001-21684 (Page 4, FIGS. 1 and 2)

  In the structure of the radiation absorber of Patent Document 1, the number of steel outer cylindrical plates corresponding to the number of copper ribs that are heat transfer members is required, the welding amount is enormous and the cost is high.

  In addition, the angle on the outer surface side of the copper rib is an obtuse angle (90 degrees or more), and it is extremely difficult to weld the outer cylinder unless the copper rib is welded or bolted to the storage container body. The cooling performance cannot be ensured due to insufficient connection with the outer cylinder.

  In the structure of the radiation absorber of Patent Document 2, a method of connecting the copper heat transfer fin, the storage container main body, and the outer cylinder is not described. In general, it is difficult to mechanically connect or contact the copper heat transfer fins to both the storage container main body and the outer cylinder, and it is considered difficult to release heat from the storage container main body to the outside.

  An object of the present invention is to provide a radioactive substance storage container formed by pouring and solidifying a neutron absorbing material into a space formed between a storage container main body and an outer cylinder, both of the outer surface of the storage container main body and the inner surface of the outer cylinder. The heat transfer fins are brought into surface contact with a sufficient force to improve the thermal conductivity and lower the temperature of the central portion of the storage container body.

  In order to achieve the above-mentioned object, the present invention sets the radial dimension of the heat transfer fin arranged inside the neutron absorber higher than the inner surface of the outer cylinder, and with a low load when the outer cylinder is pressed during assembly. The heat transfer fin has a flexible cross-sectional shape, and the outside of the heat transfer fin is brought into contact with the inner surface of the outer cylinder to achieve good heat conductivity.

  According to the present invention, the radioactive material storage in which the heat transfer fin disposed inside the neutron absorber is reliably brought into contact with the inner surface of the outer cylinder to ensure good thermal conductivity and the temperature of the central portion of the storage container is lowered. A container is obtained.

  Next, with reference to FIG. 1 thru | or FIG. 19, the Example of the radioactive substance storage container by this invention is described.

  FIG. 1 is a perspective view showing the overall structure of a radioactive substance storage container according to the present invention.

  The cylindrical storage container body 1 has a bottom made of alloy steel in order to prevent leakage of radioactive substances to the outside, and a primary lid 2 and a secondary lid 4 by a large number of bolts (not shown) on the top. And are attached.

  After the spent fuel is inserted in the fuel pool of the nuclear power plant and sealed with the primary lid 2, the inside of the primary lid 2 Resin 3 containing a large amount of boron B having a high neutron absorption capability as a neutron absorber is contained.

  On the outer peripheral side of the storage container body 1, a large number of resin blocks in which a resin 8 containing a large amount of boron B as a neutron absorber is cast in a boat-like structure made of an aluminum alloy having a high thermal conductivity are radially arranged. is there.

  In order to hold these resins 8, the outer cylinder 6 is attached in the circumferential direction by welding. At both ends of the outer cylinder 6, end plates 9 for attaching shock absorbers that relieve the impact load when the radioactive substance storage container is dropped are also provided.

  Furthermore, four trunnions 10 are provided on the upper part of the radioactive substance storage container, and two are provided on the lower part for hanging the suspension when the radioactive substance storage container is transported by the crane.

  A support cylinder 11 is inserted inside the storage container body 1, and grooves perpendicular to each other are formed on the inner surface of the support cylinder 11, and a basket plate 12 is incorporated therein. The basket structure in which the basket plates 12 are assembled in a lattice shape accommodates the spent fuel assemblies 14.

  FIG. 2 is a plan sectional view showing the structure of a radioactive substance storage container according to Embodiment 1 of the present invention.

  The basket structure is made of two types of materials, stainless steel and aluminum alloy.

  The basket plate 12 is stainless steel to which B4C is added as a neutron absorber. The concentration of boron B is about 1% by weight. Grooves having a depth of ¼ of the plate width are processed from the upper side and the lower side of the basket plate 12, respectively, and the horizontal and vertical plates are stacked in a direction perpendicular to the paper surface in FIG. Thus, a lattice structure for inserting spent fuel is formed.

  The basket plate 12 made of boron-containing stainless steel ensures subcriticality of the stored fuel assembly 14.

  However, since the basket plate 12 is austenitic stainless steel and has a slightly low thermal conductivity, the basket plate 13 made of an aluminum alloy having a good thermal conductivity is used as the basket structure in order to ensure the thermal conduction of the entire basket structure. It is arranged near the center.

  The aluminum alloy basket plate 13 has a thermal conductivity of about 200 W / m · K, and includes a support cylinder 11, a storage container body 1, a heat transfer fin 7, a resin 8, a steel fin 5 made of carbon steel, and an outer cylinder. 6, The heat generated from the stored spent fuel is efficiently radiated to the outside through the primary lid 2 and the secondary lid 4.

  Gamma rays and neutron rays are emitted from the spent fuel. The storage container body 1 is made of low alloy steel and has a thickness of 200 mm or more in order to increase the ability to absorb γ rays. On the other hand, since the storage container body 1 has a low neutron absorption capability, in order to efficiently absorb neutrons outside the storage container body 1, the space surrounded by the storage container body 1, the carbon steel fins 5, and the outer cylinder 6 is A resin 8 containing a predetermined amount of hydrogen or B4C is charged.

  8 to 12 carbon steel fins 5 are installed in the circumferential direction. With the carbon steel fins 5 alone, heat from the stored spent fuel assembly 14 cannot be released to the outer cylinder 6.

  Therefore, a large number of aluminum heat transfer fins 7 having good thermal conductivity are arranged in the resin 8.

  FIG. 3 is a plan sectional view showing a detailed structure around the filling portion of the resin 8 in Example 1 of the radioactive substance storage container according to the present invention.

  Carbon steel fins 5 are attached radially to the outer surface of the storage container body 1 by fillet welding 16 in the radial direction. The cross-sectional shape of the heat transfer fin 7 is substantially L-shaped. The curvature of the bottom surface of the heat transfer fin 7 is made to coincide with the curvature of the outer diameter of the storage container body 1 to improve the heat conduction from the storage container body 1. Alternatively, as will be described later, the curvature of the bottom surface of the heat transfer fin 7 is made slightly larger than the curvature of the outer diameter of the storage container body 1, the outer cylinder 6 is assembled, and the heat transfer fin 7 is attached to the outer surface of the storage container body 1. When pressed, the bottom surface is in contact with the outer surface of the storage container body 1 so that heat conduction is improved.

  The shape of the rising portion extending in the radial direction of the L-shaped cross section of the heat transfer fin 7 is a semi-elliptical shape, and extends to a point slightly beyond the top, so that it is almost a quarter elliptical shape. If the cross-sectional shape of the heat transfer fins 7 is such a ¼ ellipse shape, the outer cylinder 6 can be easily attached because it is easily bent inward.

  FIG. 4 is a plan sectional view showing the height relationship between the heat transfer fins 7 and the carbon steel fins 5 in the radial direction of the storage container body 1. Before the heat transfer fin 7 and the outer cylinder 6 are assembled, the height of the heat transfer fin 7 in the radial direction is several mm higher than that of the carbon steel fin 5. When the end of the outer cylinder 6 is welded to the outer peripheral side of the carbon steel fin 5, the outer cylinder 6 is placed in contact with the outer side of the heat transfer fin 7, and the outer cylinder 6 is pressed against the heat transfer fin 7 from the outer side. The vicinity of the top of the ¼ ellipse of the heat transfer fin 7 is bent inward, the end of the outer cylinder 6 is brought into contact with the outside of the carbon steel fin 5, and welding is performed to fix the outer cylinder 6.

  After welding, as shown in FIG. 3, the outside of the top of the ¼ ellipse of the heat transfer fin 7 is in close contact with the inner surface of the outer cylinder 6, so heat from the spent fuel is removed from the storage container body 1. The cylinder 6 can escape efficiently.

  Next, the manufacturing method of the radioactive substance storage container by this invention is demonstrated.

  FIG. 5 is a longitudinal sectional view showing an example of a method for assembling the carbon steel fins 5, the heat transfer fins 7, and the outer cylinder 6.

  The central axis of the storage container body 1 to which the support cylinder 11 is attached is set to a substantially horizontal state, and the end plate 9 at the lower end and the carbon steel fin 5 are welded.

  When the storage container main body 1 is viewed from the side, as shown in FIG. 5, the center of the section divided by the carbon steel fins 5 and from which the heat transfer fins 7 are attached is positioned at approximately 12 o'clock of the watch. The heat transfer fins 7 are arranged in this section divided by the carbon steel fins 5. The inside of the outer cylinder 6 is placed on the heat transfer fin 7. In order to press the outer cylinder 6 against the heat transfer fins 7, it comprises a pressing plate 40, a pressing element 41, and a pressing block 42 that are long in the axial direction of the storage container body 1, and the tips of the plurality of pressing elements 41 are on the outer surface of the outer cylinder 6. Prepare a pressing jig that matches the curvature.

  FIG. 6 is a longitudinal sectional view showing a state in which the outer cylinder 6 is pressed to the height of the carbon steel fins 5 by the pressing jigs 40, 41, 42.

  As shown by a broken line in FIG. 4, the outer cylinder 6 is pressed to a height that is in contact with the outside of the carbon steel fin 5 by the pressing jigs 40, 41, 42 using a hydraulic jack or the like.

  Next, as shown in FIG. 3, the end of the outer cylinder 6 is fixed to the carbon steel fin 5 by welding 17. This operation is repeated in each section partitioned by the carbon steel fins 5 to finish the shape shown in FIG. In this state, the space surrounded by the storage container main body 1, the carbon steel fins 5, and the outer cylinder 6 in which the heat transfer fins 7 are arranged remains low in neutron absorption capability. Therefore, the space in which the heat transfer fins 7 are arranged surrounded by the storage container main body 1, the carbon steel fins 5 and the outer cylinders 6 is filled with a kneaded liquid resin 8 containing a predetermined amount of hydrogen or B4C as a neutron absorber. I will do it.

  Since this space is cut by the heat transfer fins 7, the resin 8 is filled in each partitioned section. When the filling of the resin 8 is completed and the resin 8 is sufficiently solidified, the upper end plate 9 is attached to the storage container body 1 and the outer cylinder 6 by welding.

  By this manufacturing method, the resin 8 as the neutron absorber can be confined in the sealed space.

  FIG. 7 is a plan sectional view showing the structure of a radioactive substance storage container according to Embodiment 2 of the present invention.

  In the second embodiment, the orientation of the heat transfer fins 7 is symmetrically arranged across the center of the section in one section partitioned by the carbon steel fins 5.

  In Example 1 of FIG. 2, when arranging the heat transfer fins 7 in the space surrounded by the storage container main body 1, the carbon steel fins 5, and the outer cylinder 6, the direction of the heat transfer fins 7 is the same in the circumferential direction. Is arranged. In this method, when the pressing jigs 40, 41, and 42 are pressed against the heat transfer fins 7 during assembly as shown in FIG. 5, the outer cylinder 6 is displaced in the clockwise direction, which makes it difficult to assemble and weld. Is to avoid.

  FIG. 8 is a plan sectional view showing the structure of the main part of a radioactive substance storage container according to Embodiment 3 of the present invention.

  In Example 1 of FIG. 2 and Example 2 of FIG. 7, the heat transfer fins 7 disposed in the space surrounded by the storage container main body 1, the carbon steel fins 5, and the outer cylinder 6 are provided on the outer surface of the storage container main body 1. It is only put. Accordingly, when the outer cylinder 6 is pressed to the outside of the heat transfer fin 7, a force acts so that the outer peripheral side of the quarter elliptical shape of the heat transfer fin 7 is inclined in the right direction in the figure. There is a possibility that the surface of the heat fin 7 that is in contact with the outer surface of the storage container body 1 floats away.

  In the third embodiment, in order to prevent the contact surface from floating, the tip of the surface of the heat transfer fin 7 that is in contact with the storage container main body 1 is joined to the adjacent heat transfer fin 7 by welding 18.

  FIG. 9 is a plan sectional view showing the structure of the main part of a radioactive substance storage container according to Embodiment 4 of the present invention.

  As in the third embodiment, in order to prevent the contact surface from floating, the tip of the portion of the heat transfer fin 7 that contacts the outer surface of the storage container body 1 is extended in the radial direction, and the extended portion is adjacent to the adjacent portion by the bolt 19 and the nut 20. Connect and fix with heat transfer fin 7.

  FIG. 10 is a plan sectional view showing the structure of the main part of Example 5 of the radioactive substance storage container according to the present invention.

  As in the third embodiment, in order to prevent the contact surface from floating, a hole is formed near the center of the surface of each heat transfer fin 7 in contact with the storage container body 1, a female screw is opened in the storage container body 1, and a bolt At 21, the heat transfer fins 7 are fixed.

  FIG. 11 is a plan sectional view showing the structure of the main part of Example 6 of the radioactive substance storage container according to the present invention. The cross-sectional shape of the heat transfer fin 7 is substantially L-shaped as a whole. The L-shaped surface 31 extending in the circumferential direction is arranged so as to contact the outer surface of the storage container main body 1, and the other surface 32 extending in the radial direction of the L-shape is substantially straight in the radial direction. The eaves 33 are extended in a different direction, and a bent portion 34 is formed on the outer peripheral side of the tip of the extended eaves 33, and the outside of the bent portion 34 is brought into contact with the inner surface of the outer cylinder 6.

  When the cross section of the heat transfer fin 7 is formed in such a shape, there is an advantage that it is easy to manufacture. However, the force to bend the extended eaves 33 must be higher than that of the quarter-elliptical heat transfer fin 7 shown in FIG.

  FIG. 12 is a plan sectional view showing the structure of the main part of a radioactive substance storage container according to Embodiment 7 of the present invention.

  The substantially L-shaped heat transfer fins 7 of the above-described embodiments are long members extending over the entire length of the axial length on the outer surface of the storage container body 1. The outer cylinder 6 in contact with the heat transfer fins 7 is bent using a four-point bending roll or the like. In the bending process, linearity is not always ensured over the entire axial length.

  Thus, in the seventh embodiment, a plurality of slits 35 are formed in the middle of the heat transfer fin 7 in the longitudinal direction. In FIG. 12, seven slits are formed. In general, the greater the number of slits, the better the heat transfer performance can be maintained with a sufficient contact with the outer cylinder 6 at the top of the ¼ ellipse shape. As a result of the experiment, it is desirable that the radial depth of the slit is about half the height of the heat transfer fin 7.

  FIG. 13 is a plan sectional view showing the structure of the main part of an embodiment 8 of the radioactive substance storage container according to the present invention.

The thermal expansion coefficient of the resin 8 which is a neutron absorber is about 40 × 10 ⁻⁶ mm / mm · ° C., which is more than three times the thermal expansion coefficient 12 × 10 ⁻⁶ mm / mm · ° C. of the carbon steel fin 5. is there.

  The vicinity of the resin 8 part is exposed to a high temperature of 100 ° C. or more by heat transfer from the stored spent fuel. In this environment, a displacement of about 0.4 mm occurs on the outer peripheral side of the carbon steel fins 5 due to the difference in thermal expansion between the resin 8 and the carbon steel. When this displacement is applied to the carbon steel fins 5 as strain, the generated stress exceeds 500 MPa. Since the outer cylinder 6 is fixed to the carbon steel fin 5 at the end thereof by welding 17, the deformation stress is concentrated on the welded portion.

  In Example 8, as shown in FIG. 13, members 36 that form a space so as to be in contact with the inner surface of the outer cylinder 6 are arranged on both sides of the radially outer end portion of the carbon steel fin 5, and the welded portion is formed. The concentration of deformation stress is eliminated.

  As described above, the members 36 are arranged only on both sides of the outer end portion of the carbon steel fin 5 to form a space. The thermal expansion of the resin 8 at a position away from the carbon steel fin 5 is bent with respect to the welded portion. This is because it acts as a stress and its influence is small.

  As a member for forming the space portion so as to be in contact with the inner surface of the outer cylinder 6 on both sides of the outer end portion of the carbon steel fin 5, a member having a high spatial density as shown in FIGS.

  FIG. 14 shows a member in which a rectangular pipe 50 extending in the axial direction of the storage container main body 1 is formed, and ribs 51 are arranged obliquely with respect to the radial direction and a space 52 is formed therebetween. This member absorbs the radial extension due to the thermal expansion of the resin 8 by the bending deformation of the ribs 51.

  FIG. 15 shows a member in which a rib 54 is disposed obliquely with respect to the radial direction between two flat plates 53 extending in the axial direction of the storage container body 1 and a space 55 is formed therebetween. This structure is easier to deform than the thermal expansion absorbing member shown in FIG.

  FIG. 16 shows a member in which a space 57 is simply formed by a pipe 56 having a rectangular cross section.

  FIG. 17 shows a member in which a space 59 is simply formed by a pipe 58 having an elliptical cross section.

  FIG. 18 is a plan sectional view showing the structure of the main part of a radioactive substance storage container according to Embodiment 9 of the present invention.

  As described in connection with Example 8 in FIG. 13, the thermal expansion coefficient of the resin 8 which is a neutron absorber and the thermal expansion coefficient of the carbon steel fin 5 are more than three times different from each other. It is necessary to absorb the displacement caused by the difference in thermal expansion between the resin 8 and the carbon steel fins 5 when the periphery of the resin 8 is exposed to 100 ° C. or higher due to heat transfer.

  In the ninth embodiment, a member 37 having a high elastic deformation capability is attached to the inner surface of the outer cylinder 6, and a member 38 having a high elastic deformation capability is attached to the outer peripheral side of the legs of the aluminum alloy heat transfer fins 7.

  19 corresponds to FIG. 4 of the first embodiment, the height relationship between the heat transfer fins 7 and the carbon steel fins 5 in the radial direction of the storage container body 1 of the ninth embodiment, and the silicon resin 37, It is a plane sectional view showing the installation situation of 38.

  The member 37 attached to the inner surface of the outer cylinder 6 must be able to withstand high heat during welding of the outer cylinder 6 and the carbon steel fins 5. As a material having such heat resistance and high elastic deformation ability, there is a silicon-based foamed resin.

  Generally called foam, it is a sponge-like material and has a high deformation absorption capacity. In addition, since it is a silicon-based resin, it has good heat resistance.

  The silicon resin plate is attached to the outer peripheral side of the leg portion of the aluminum alloy heat transfer fin 7 and the inner surface of the outer cylinder 6, assembled, welded, and then the resin 8 is injected.

  Even if the temperature around the resin 8 rises while using the radioactive substance storage container, the thermal expansion deformation in the radial direction is absorbed by the silicon-based resins 37 and 38 attached to the outer cylinder 6 and the heat fin 7. In the axial direction of the radioactive substance storage container, a space is provided above the resin 8 and is freely expanded.

It is a perspective view which shows the whole structure of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of Example 1 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the detailed structure of the filling part periphery of the resin 8 in Example 1 of the radioactive substance storage container by this invention. 4 is a cross-sectional plan view showing the height relationship between the heat transfer fins 7 and the carbon steel fins 5 in the radial direction of the storage container body 1. FIG. It is a longitudinal cross-sectional view which shows an example of the assembly method of the carbon steel fin 5, the heat-transfer fin 7, and the outer cylinder 6. FIG. 4 is a longitudinal sectional view showing a state in which the outer cylinder 6 is pressed to the height of the carbon steel fin 5 by the pressing jigs 40, 41, and 42. FIG. It is a plane sectional view which shows the structure of Example 2 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of the principal part of Example 3 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of the principal part of Example 4 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of the principal part of Example 5 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of the principal part of Example 6 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of the principal part of Example 7 of the radioactive substance storage container by this invention. It is a plane sectional view which shows the structure of the principal part of Example 8 of the radioactive substance storage container by this invention. FIG. 4 is a cross-sectional view showing members that form a space so as to be in contact with the inner surface of the outer cylinder 6 on both sides of the outer end portion of the carbon steel fin 5. FIG. 4 is a cross-sectional view showing members that form a space portion so as to be in contact with the inner surface of the outer cylinder 6 on both sides of the outer end portion of the carbon steel fin 5. FIG. 4 is a cross-sectional view showing members that form a space portion so as to be in contact with the inner surface of the outer cylinder 6 on both sides of the outer end portion of the carbon steel fin 5. FIG. 4 is a cross-sectional view showing members that form a space portion so as to be in contact with the inner surface of the outer cylinder 6 on both sides of the outer end portion of the carbon steel fin 5. It is a plane sectional view which shows the structure of the principal part of Example 9 of the radioactive substance storage container by this invention. It is a plane sectional view showing the height relationship between the heat transfer fins 7 and the carbon steel fins 5 in the radial direction of the storage container body 1 of Example 9 and the installation status of the silicon-based resins 37 and 38.

Explanation of symbols

1 Storage container body 2 Primary lid 3 Resin (neutron absorber)
4 Secondary lid 5 Carbon steel fin 6 Outer cylinder 7 Heat transfer fin 8 Resin (neutron absorber)
9 End plate 10 Trunnion 11 Support cylinder 12 Basket plate 13 Aluminum alloy basket plate 14 Spent fuel assembly 16 Fillet weld 17 Weld 18 Heat transfer fin joint weld 19 Bolt 20 Nut 21 Bolt 31 L-shaped surface extending in the circumferential direction 32 Another surface extending in the radial direction of the L-shape 33 Eaves 34 Bending portion 35 on the outer peripheral side of the tip Slit 36 Thermal expansion absorbing member 37 Thermal expansion absorbing member 38 Thermal expansion absorbing member 40 Press plate 41 Presser 42 Press block 50 Pipe 51 Rib 52 Space 53 Flat plate 54 Rib 55 Space 56 Pipe 57 Space 58 Pipe 59 Space

Claims (15)

A storage fin main body for storing a radioactive substance, an outer cylinder that coaxially surrounds the storage container main body, and a steel fin that is radially fixed to the storage container main body and divides a space formed by the storage container main body and the outer cylinder into a plurality of parts And a radioactive substance storage container having a neutron absorber filled in each partitioned space,
When a bottom part contacting the outer surface of the storage container body and a radial direction of the storage container body extend higher than the steel fin and the tip is obliquely in contact with the inner surface of the outer cylinder to fix the outer cylinder to the steel fin A radioactive substance storage container comprising a plurality of heat transfer fins, each of which has a rising portion that bends toward the storage container body and releases heat from spent fuel to the outside. A storage container main body for storing a radioactive substance, an outer cylinder that coaxially surrounds the storage container main body, and a steel fin that is radially fixed to the storage container main body and divides a space formed by the storage container main body and the outer cylinder into a plurality of parts And a radioactive substance storage container having a neutron absorber filled in each partitioned space,
When a bottom part contacting the outer surface of the storage container body and a radial direction of the storage container body extend higher than the steel fin and the tip is obliquely in contact with the inner surface of the outer cylinder to fix the outer cylinder to the steel fin A plurality of heat transfer fins that have a rising portion that bends toward the storage container main body and releases heat from spent fuel to the outside, and are arranged in each of the partitioned spaces,
A radioactive substance storage container, wherein a thermal expansion absorbing member that forms a space not filled with the neutron absorbing material is disposed in contact with an inner surface of the outer cylinder on both sides of a radially outer end of the steel fin. In the radioactive substance storage container according to claim 2,
The radioactive substance storage container, wherein the thermal expansion absorbing member is a pipe having a rectangular or elliptical cross section extending in the axial direction of the storage container main body. In the radioactive substance storage container according to claim 2,
The thermal expansion absorbing member includes a pipe that extends in the axial direction of the storage container main body and has a rectangular cross section, and a rib that is disposed obliquely with respect to the radial direction inside the rectangular pipe. Radioactive material storage container. In the radioactive substance storage container according to claim 2,
The thermal expansion absorbing member is composed of two flat plates extending in the axial direction of the storage container main body, and a rib disposed obliquely with respect to the radial direction between the two flat plates. Storage container. A storage fin main body for storing a radioactive substance, an outer cylinder that coaxially surrounds the storage container main body, and a steel fin that is radially fixed to the storage container main body and divides a space formed by the storage container main body and the outer cylinder into a plurality of parts And a radioactive substance storage container having a neutron absorber filled in each partitioned space,
When a bottom part contacting the outer surface of the storage container body and a radial direction of the storage container body extend higher than the steel fin and the tip is obliquely in contact with the inner surface of the outer cylinder to fix the outer cylinder to the steel fin A plurality of heat transfer fins that have a rising portion that bends toward the storage container main body and releases heat from spent fuel to the outside, and are arranged in each of the partitioned spaces,
A radioactive substance storage container, wherein a thermal expansion absorbing member that absorbs thermal expansion of the neutron absorbing material is attached to an outer peripheral surface of a bottom portion of the heat transfer fin and an inner peripheral surface of the outer cylinder. The radioactive substance storage container according to claim 6,
The radioactive material storage container, wherein the thermal expansion absorbing member is a flexible heat-resistant silicone resin. In the radioactive substance storage container according to any one of claims 1 to 7,
The radioactive substance storage container, wherein the rising portion of the heat transfer fin has a substantially elliptic shape. In the radioactive substance storage container according to any one of claims 1 to 7,
A radioactive substance storage container, wherein an eave is extended in a direction to bend from a rising portion of the heat transfer fin, and a bent portion to be brought into contact with an inner surface of the outer cylinder is formed on an outer peripheral side of a tip end of the eaves. The radioactive substance storage container according to any one of claims 1 to 9,
A radioactive substance storage container, wherein a plurality of slits are formed in an axial direction of the heat transfer fin storage container main body. The radioactive substance storage container according to any one of claims 1 to 10,
A radioactive substance storage container characterized in that the heat transfer fins arranged in each of the partitioned spaces are divided into half and are arranged so as to bend in opposite directions across the center in the circumferential direction of each space. The radioactive substance storage container according to any one of claims 1 to 11,
The radioactive substance storage container characterized by joining the bottom part which contact | connects the outer surface of the said storage container main body of the said heat transfer fin with the bottom part of the adjacent heat transfer fin. The radioactive substance storage container according to any one of claims 1 to 11,
The bottom end of the heat transfer fin in contact with the outer surface of the storage container main body is raised in an L shape, and the L shape portion and the rising portion of the adjacent heat transfer fin are coupled by a bolt and a nut. Radioactive material storage container. The radioactive substance storage container according to any one of claims 1 to 11,
The radioactive substance storage container characterized by fixing the bottom part which contact | connects the outer surface of the said storage container main body of the said heat-transfer fin to the said storage container main body with a volt | bolt. The radioactive substance storage container according to any one of claims 1 to 14,
The radioactive substance storage container characterized in that the curvature of the bottom portion of the heat transfer fin is substantially matched with the curvature of the outer surface of the storage container body.

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