JP2016183880A - Lid bolt hole plug for radioactive substance storage container, and radioactive substance storage method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate operations of waterproofing and removal of a bolt hole of a radioactive substance storage container.SOLUTION: A cask with a trunk 112 whose upper part has an opening and whose lower part is blocked at the bottom and a primary lid 131 to be fixed by tightening a bolt in a first lid bolt hole 141C formed at the opening of the trunk 112 in a manner to block the opening includes: an insertion part 2 to be inserted into the first lid bolt hole 141C so as to water proof the first lid bolt hole 141C when housing a radioactive substance in the trunk 112; a sealant 3 provided along the outer periphery of a part where the insertion part 2 is inserted into the first lid bolt hole 141C; and a pressing part 4 to press the sealant 3 to the inner surface of the first lid bolt hole 141C without engaging with a female screw part of the first lid bolt hole 141C.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lid bolt hole plug of a radioactive substance storage container used when the radioactive substance is stored in the radioactive substance storage container, and a radioactive substance storage method of the radioactive substance storage container.

  Radioactive waste generated in a nuclear power plant nuclear reactor or the like is stored in a radioactive material storage container, transported to a storage facility or a reprocessing facility, and stored or reprocessed. In such a radioactive substance storage container, a dry type container contains a radioactive substance in a container that has been submerged in the pool water, and a lid is installed to lift the container from the pool. The inside water is discharged, the lid is fixed with a bolt, the inside of the container is vacuum-dried, and finally, the container is filled with an inert gas.

  In this way, after the radioactive substance is stored in the container submerged in the pool water, the water in the container is discharged and dried, but the water remaining in the bolt hole for fixing the lid is removed by tightening the bolt. It is difficult to remove because it is confined to the joint between the lid and the container.

  Conventionally, for example, in Patent Document 1, after removing the inner lid bolted to the opening of the bottomed cylindrical cask main body and the outer lid having a larger diameter outside the pool, for example, in Patent Document 1 with respect to such a problem, , A spent nuclear fuel storage method for storing spent nuclear fuel in a cask body in a pool, wherein a bolt hole waterproof cap jig is attached to a bolt hole provided in an inner lid support portion of the cask body, and the jig is The attached cask body is shown to be handled in the pool.

Japanese Patent Laying-Open No. 2005-043058

  The bolt hole waterproof cap jig shown in Patent Document 1 has a male screw portion screwed into a female screw portion of the bolt hole, and is attached by tightening into the bolt hole. Further, the bolt hole waterproof cap jig shown in Patent Document 1 is removed and replaced with a fixing bolt when the lid is fixed. Therefore, there is a problem that a burden is large in the work of tightening and removing from a large number of bolt holes.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and the lid bolt hole plug of the radioactive substance storage container and the radioactive substance capable of easily performing the work of waterproofing or removing the bolt hole of the radioactive substance storage container. An object is to provide a storage method.

  The lid plug hole plug of the radioactive substance storage container of the present invention is formed in the opening in a form in which an opening is formed in the upper part and the lower part is closed at the bottom, and the opening of the trunk is closed. A radioactive substance storage container having a lid part fixed by tightening a bolt in a lid bolt hole, and a lid of the radioactive substance storage container for waterproofing the lid bolt hole when the radioactive substance is stored in the trunk part In the bolt hole plug, an insertion portion inserted into the lid bolt hole, a sealing material provided along an outer peripheral portion of a portion where the insertion portion is inserted into the lid bolt hole, and a female screw of the lid bolt hole A pressing portion that presses the sealing material against the inner surface of the lid bolt hole regardless of the portion.

  According to the lid bolt hole plug of the radioactive substance storage container, the waterproof function can be obtained in a short time by including the pressing portion that presses the sealing material against the inner surface of the lid bolt hole regardless of the female screw portion of the lid bolt hole. Therefore, the work of waterproofing or removing the lid bolt hole of the radioactive substance storage container can be easily performed.

  In the lid bolt hole plug of the radioactive substance storage container according to the present invention, the pressing portion is provided at an insertion end of the insertion portion to support the sealing material, and the insertion portion with respect to the insertion portion. And a moving member that expands the diameter of the sealing material to the outside of the sealing material support portion in a movement approaching the insertion end, and the moving member approaches the insertion end. A movement restricting unit that maintains the movement position.

  According to the lid bolt hole plug of the radioactive substance storage container, a waterproof function can be obtained in a short time, and the work of performing waterproofing or removal of the lid bolt hole of the radioactive substance storage container is easily performed. be able to.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the movement restricting portion is provided with a cam portion that is provided in a portion where the insertion portion extends from the lid bolt hole and pushes the moving member toward the insertion end side. It is characterized by having.

  According to the lid bolt hole plug of the radioactive substance storage container, by having the cam portion, it is possible to realize the operation of maintaining the moving position where the moving member approaches the insertion end.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the movement restricting portion is a lock that maintains a moving position where the moving member approaches the insertion end in response to an pushing operation to the insertion end side of the moving member. It has an alternate type latch mechanism that switches between a state and a release state in which the movement position of the moving member approaching the insertion end is released.

  According to the lid plug hole plug of the radioactive substance storage container, it is possible to easily switch between the locked state and the released state, and the work of waterproofing or removing the lid bolt hole of the radioactive substance storage container is performed. The effect easily performed can be remarkably obtained.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the movement restricting portion is provided to be rotatable around the insertion portion by screwing, and rotates to push the moving member to the insertion end side by a rotation operation. It is characterized by forming a member.

  According to the lid bolt hole plug of the radioactive substance storage container, it is possible to realize an operation of maintaining the moving position where the moving member approaches the insertion end by pushing the moving member to the insertion end side by rotating operation.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the insertion portion has a wiping member at an insertion end thereof.

  According to the lid bolt hole plug of the radioactive substance storage container, when the lid bolt hole plug is removed, the moisture remaining in the opening portion of the lid bolt hole and the through hole of the lid portion can be wiped off by the wiping member.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the base is provided extending from the insertion end of the insertion portion and is inserted into the inner portion of the lid bolt hole and reaching the inner portion of the lid bolt hole. It is characterized by having.

  According to the lid bolt hole plug of the radioactive substance storage container, the base can be stably installed with respect to the lid bolt hole.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the lid portion has an inner lid that closes the opening of the trunk portion, and an outer lid that closes a space outside the inner lid, and A plurality of through holes that penetrate the bolts are provided in the inner lid and the outer lid, and the insertion portion, the sealing material, and the pressing portion are formed so as to be able to be inserted into the through holes of the inner lid, In addition, the insertion portion is formed such that a length dimension extending outside the lid bolt hole is larger than a length dimension of the through hole of the inner lid.

  According to the lid bolt hole plug of the radioactive substance storage container, since the inner lid is arranged in the trunk in the pool water, the insertion portion, the sealing material, and the pressing portion can be inserted into the through hole of the inner lid. By being formed, the inner lid can be arranged without interfering with these configurations. Moreover, since the length of the insertion portion extending outside the inner lid bolt hole is larger than the length of the through hole of the inner lid, the inner portion is Removal from the through hole of the lid can be easily performed.

  In the lid bolt hole plug of the radioactive substance storage container of the present invention, the lid portion has an inner lid that closes the opening of the trunk portion, and an outer lid that closes a space outside the inner lid, The trunk portion has a plurality of inner lid bolt holes for fixing the inner lid by tightening bolts, and a plurality of outer lid bolt holes for fixing the outer lid by fastening bolts. It has the connection part which connects two or more used for each said outer cover bolt hole.

  According to the lid bolt hole plug of this radioactive substance storage container, it can attach to a some outer lid bolt hole collectively by being connected by a connection part.

  In the radioactive substance storage method of the present invention, the upper portion is formed with an opening portion and the lower portion is closed with a bottom portion, and the inner lid bolt hole formed in the opening portion in a manner of closing the opening portion of the trunk portion. A radioactive substance comprising: an inner lid that is fixed by tightening a bolt; and an outer lid that is fixed by tightening a bolt into an outer lid bolt hole formed in the opening in a manner to close a space outside the inner lid. Regarding the storage container, in the radioactive substance storage method for storing a radioactive substance in the radioactive substance storage container, any one of the radioactive substances described above is stored in the inner lid bolt hole and the outer lid bolt hole in the trunk portion outside the pool. Attaching a lid bolt hole plug of a container; sinking the trunk into the pool; storing the radioactive substance in the trunk in the pool; and underwater in the pool Disposing the inner lid with respect to the barrel, lifting the barrel from the pool, removing the lid bolt hole plug, draining the barrel, and removing the inner lid Including a step of bolting and fixing, a step of vacuum-drying the inside of the body portion inside the inner lid, filling with an inert gas, and a step of bolting and fixing the outer lid. Features.

  According to this radioactive substance storage method, the lid bolt hole plug is provided with the pressing portion that presses the sealing material against the inner surface of the lid bolt hole regardless of the female screw portion of the lid bolt hole, so that the waterproof function can be obtained in a short time. Therefore, the work of waterproofing or removing the lid bolt hole of the cask can be easily performed. As a result, the working time for storing the radioactive substance can be shortened.

  In the radioactive substance storage method of the present invention, in the step of attaching a lid bolt hole plug to the inner lid bolt hole and the outer lid bolt hole in the trunk portion, the lid bolt is provided at a plurality of arbitrarily selected locations of the inner lid bolt hole. A guide pin extending from the inner lid bolt hole with a longer dimension than the hole plug is attached, and in the step of removing the lid bolt hole plug, the guide pin is removed together with the lid bolt hole plug.

  According to this radioactive substance storage method, by using the guide pin, it is possible to prevent interference with the lid bolt hole plug of the inner lid in the operation of installing the inner lid on the trunk, and the waterproof function by the lid bolt hole plug Can be maintained.

  In the radioactive substance storage method of the present invention, an inner surface of the opening of the lid bolt hole is smooth without having irregularities, and has an opening peripheral surface having a diameter larger than that of the female screw portion. In the step of attaching the lid bolt hole plug to the bolt hole and the outer lid bolt hole, the sealing material of the lid bolt hole plug is arranged on the peripheral surface of the opening.

  According to this radioactive substance storage method, the waterproof function by the lid bolt hole plug can be improved by disposing the sealing material on the smooth peripheral surface of the opening without unevenness.

  ADVANTAGE OF THE INVENTION According to this invention, the operation | work which implements waterproofing of the bolt hole of a radioactive substance storage container or removes can be performed easily.

FIG. 1 is a side sectional view showing an example of a cask as a radioactive substance storage container to which a lid bolt hole plug according to an embodiment of the present invention is applied. FIG. 2 is a plan sectional view of the cask shown in FIG. FIG. 3 is a partially enlarged side sectional view of the cask shown in FIG. FIG. 4 is a side view of the lid bolt hole plug according to the embodiment of the present invention. FIG. 5 is a side view of the use state of the lid bolt hole plug shown in FIG. FIG. 6 is a side view of a modified example of the lid bolt hole plug shown in FIG. FIG. 7 is a side view of another example of the lid bolt hole plug according to the embodiment of the present invention. FIG. 8 is a side view of the lid bolt hole plug shown in FIG. 7 in use. FIG. 9 is a side view of a modified example of the lid bolt hole plug shown in FIG. FIG. 10 is a side view of another example of the lid bolt hole plug according to the embodiment of the present invention. FIG. 11 is a side view of the cover bolt hole plug shown in FIG. 10 in use. 12 is a side view of a modified example of the lid bolt hole plug shown in FIG. FIG. 13 is a process diagram of a radioactive substance storage method using a lid bolt hole plug according to an embodiment of the present invention. FIG. 14 is a side view of another example of the radioactive substance storage method using the lid bolt hole plug according to the embodiment of the present invention. FIG. 15 is a side view of another example of the lid bolt hole plug according to the embodiment of the present invention. 16 is a side view showing the operation of the lid bolt hole plug shown in FIG. FIG. 17 is a plan view of another example of the lid bolt hole plug according to the embodiment of the present invention. 18 is a side view of the lid bolt hole plug shown in FIG. FIG. 19 is a side view of another example of the lid bolt hole plug according to the embodiment of the present invention.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a side sectional view showing an example of a cask as a radioactive substance storage container to which the suspension structure according to the present embodiment is applied. FIG. 2 is a plan sectional view of the cask shown in FIG. FIG. 3 is a partially enlarged side sectional view of the cask shown in FIG.

  A cask 111 as a radioactive substance storage container has a trunk portion 112, a lid portion 113, and a basket 114. The trunk portion 112 has a cylindrical shape in which an opening 122 is formed in one upper portion of the trunk main body 121 and a bottom portion (blocking portion) 123 is formed in the lower portion that is the other. The body main body 121 is provided with a cavity 124 inside, and the cavity 124 has a shape matching the outer peripheral shape of the basket 114. The basket 114 has, for example, a plurality of cells that individually store radioactive materials (not shown) that are spent fuel assemblies. The basket 114 has a basket body 114A. In the basket body 114A, radioactive substance storage portions 114B as cells arranged parallel to each other at a predetermined interval are formed continuously in the vertical direction. Here, the vertical direction is a direction along the longitudinal direction X that is the extending direction of the cylindrical central axis of the trunk body 121 in the cask 111, and corresponds to the vertical direction of the trunk body 121. And the bottom part 123 of the trunk | drum main body 121 is weld-joined or integrally molded by the lower part, and this trunk | drum main body 121 and the bottom part 123 are the forgings made from carbon steel which has a gamma ray shielding function. Stainless steel can also be used for the trunk body 121 and the bottom 123 instead of carbon steel. Further, the trunk main body 121 and the bottom 123 can be made of cast products such as spheroidal graphite cast iron or carbon steel cast steel.

  The body portion 112 has an outer cylinder 125 disposed on the outer peripheral side of the body main body 121 with a predetermined gap, and conducts heat conduction between the outer peripheral surface of the body main body 121 and the inner peripheral surface of the outer cylinder 125. A plurality of heat transfer fins 125A made of copper or steel are welded at equal intervals in the circumferential direction. The body 112 is a resin (neutron shield) 126 containing boron or a boron compound which is a polymer material containing a large amount of hydrogen and has a neutron shielding function in the space between the body main body 121 and the outer cylinder 125. Is injected and solidified through a pipe (not shown) in a fluidized state.

  In addition, the body 112 may be connected to the bottom plate 128 below the bottom 123 by a plurality of connecting plates 127 with a predetermined gap, and a resin (neutron) is formed in the space between the connecting plate 127 and the bottom plate 128. Shield) 129 is provided. Note that the connecting plate 127 may not be provided. Further, the trunnion 130 is fixed to the side surface 135 of the trunk portion 112. The trunnions 130 protrude from the cask 111 to the opposite sides in the radial direction to form a pair, and are disposed at two places in the vertical direction, and are provided at a total of at least four places.

  As shown in FIG. 1, the lid 113 includes a primary lid 131, a secondary lid 132, and a tertiary lid 133. The primary lid 131 is detachably attached to the opening 122 of the trunk main body 121 in the trunk 112. The secondary lid 132 is detachably attached to the opening 122 outside the primary lid 131. The tertiary lid 133 is detachably attached to the opening 122 outside the secondary lid 132. The primary lid 131 maintains a negative pressure on the cavity 124 side to prevent leakage of the gas filled in the cavity 124 and shields radiation (γ rays) emitted from the radioactive material stored in the cavity 124. The primary lid 131 is provided with a resin (neutron shield) 134 on the secondary lid 132 side. The secondary lid 132 has a pressure monitoring boundary pressurized against the atmosphere with the primary lid 131, and prevents leakage of gas from the primary lid 131 and secures the pressure on the cavity 124 side. The tertiary lid 133 protects the secondary lid 132 from external impacts. Although not clearly shown in the figure, a buffer portion that absorbs the impact of the secondary lid 132 may be provided between the primary lid 131 and the secondary lid 132.

  Here, attachment of the primary lid 131, the secondary lid 132, and the tertiary lid 133 to the opening 122 will be described. As shown in FIG. 3, the trunk portion 112 has a stepped portion formed on the inner peripheral portion of the opening 122 of the trunk body 121. The stepped portion includes a first step portion 141, a second step portion 142, and a third step portion 143 from the inside of the opening 122.

  The first step portion 141 includes a first inner peripheral portion 141A and a first seat surface portion 141B. 141 A of 1st inner peripheral parts have comprised the inner periphery of the trunk | drum main body 121, and are extended | stretched to the outer side of the opening part 122 in the longitudinal direction X. As shown in FIG. The first seat surface portion 141 </ b> B extends from the extending end of the first inner peripheral portion 141 </ b> A to the outer side in the radial direction of the trunk body 121 and forms a surface facing the outer side of the opening portion 122. The first seat surface portion 141 </ b> B is provided with a plurality of first lid bolt holes 141 </ b> C along the periphery of the trunk body 121. In the first step portion 141, the primary lid 131 is fixed to the trunk body 121.

  The second step 142 is located outside the opening 122 in the longitudinal direction X with respect to the first step 141. The second step portion 142 includes a second inner peripheral portion 142A and a second seat surface portion 142B. The second inner peripheral portion 142 </ b> A forms the inner periphery of the trunk body 121, and extends from the outer peripheral end of the first seat surface portion 141 </ b> B of the first step portion 141 to the outside of the opening portion 122 in the longitudinal direction X. The second seat surface portion 142 </ b> B extends from the extended end of the second inner peripheral portion 142 </ b> A to the outer side in the radial direction of the trunk body 121 and forms a surface facing the outer side of the opening portion 122. The second seat surface portion 142 </ b> B is provided with a plurality of second lid bolt holes 142 </ b> C along the periphery of the trunk body 121. In the second step portion 142, the secondary lid 132 is fixed to the trunk body 121.

  The third step portion 143 is located outside the opening portion 122 in the longitudinal direction X with respect to the second step portion 142. The third step portion 143 has a third inner peripheral portion 143A and a third seat surface portion 143B. The third inner peripheral portion 143 </ b> A forms the inner periphery of the trunk body 121, and extends from the outer peripheral end of the second seat surface portion 142 </ b> B of the second step portion 142 to the outside of the opening portion 122 in the longitudinal direction X. The third seat surface portion 143 </ b> B extends from the opening edge of the opening portion 122, which is the extended end of the third inner peripheral portion 143 </ b> A, to the outer side in the radial direction of the trunk body 121, and forms a surface facing the outside of the opening portion 122. The third seat surface portion 143 </ b> B forms an end surface on the outer side of the opening portion 122 in the trunk main body 121. The third seat surface portion 143 </ b> B is provided with a plurality of third lid bolt holes 143 </ b> C along the periphery of the trunk body 121. In the third step portion 143, the tertiary lid 133 is fixed to the trunk body 121.

  The primary lid 131 has a disc part 131A and a protruding part 131B. The disc portion 131A is formed in a disc shape having a size that can be inserted inside the second inner peripheral portion 142A of the second step portion 142. The protrusion 131B is provided so as to protrude from one side surface 131Aa at the center of the disc portion 131A, and is formed in a columnar shape with a size that can be inserted inside the first inner peripheral portion 141A of the first step portion 141. . One side surface 131Aa of the disc portion 131A is disposed on the outer peripheral portion of the disc portion 131A. The primary lid 131 has a seal groove 131C formed on one side surface 131Aa of the disc portion 131A. A seal member (for example, a metal gasket) 131D is inserted into the seal groove 131C. Further, the primary lid 131 is provided with a plurality of through holes 131E along the circumferential direction at a position on the outer peripheral portion of the disc portion 131A and avoiding the seal groove 131C. The through hole 131E is provided corresponding to the first lid bolt hole 141C provided in the first seat surface portion 141B of the first step portion 141. In the primary lid 131, the bolt 151 inserted through the through hole 131E is screwed into the first lid bolt hole 141C with one side surface 131Aa of the disk portion 131A facing the first seat surface portion 141B of the first step portion 141. As a result, the side surface 131Aa is tightened so as to be pressed against the first seat surface portion 141B, and the seal member 131D is sandwiched between the one side surface 131Aa side and the first seat surface portion 141B side. The position of the first step 141 in the opening 122 is sealed.

  The secondary lid 132 has a disc part 132A and a protruding part 132B. The disc portion 132A is formed in a disc shape with a size that can be inserted inside the third inner peripheral portion 143A of the third step portion 143. The protrusion 132B is provided so as to protrude from one side surface 132Aa at the center of the disc portion 132A, and is formed in a columnar shape with a size that can be inserted inside the second inner peripheral portion 142A of the second step portion 142. . One side surface 132Aa of the disc portion 132A is disposed on the outer peripheral portion of the disc portion 132A. Further, the secondary lid 132 has a seal groove 132C formed on one side surface 132Aa of the disc portion 132A. A seal member (for example, a metal gasket) 132D is inserted into the seal groove 132C. Further, the secondary lid 132 is provided with a plurality of through holes 132E along the circumferential direction at a position on the outer peripheral portion of the disc portion 132A and avoiding the seal groove 132C. The through hole 132 </ b> E is provided corresponding to the second lid bolt hole 142 </ b> C provided in the second seat surface portion 142 </ b> B of the second step portion 142. In the secondary lid 132, the bolt 152 inserted through the through hole 132E is inserted into the second lid bolt hole 142C in a state where the one side surface 132Aa of the disc portion 132A faces the second seat surface portion 142B of the second stepped portion 142. By screwing, the side surface 132Aa is tightened so as to be pressed against the second seat surface portion 142B, and the seal member 132D is sandwiched between the one side surface 132Aa side and the second seat surface portion 142B side. The position of the second step 142 in the opening 122 of 121 is sealed.

  The tertiary lid 133 has a disc part 133A and a projection part 133B. The disc portion 133A is formed in a disc shape with a size that covers the third seat surface portion 143B. The protrusion 133B is provided so as to protrude from the one side surface 133Aa at the central portion of the disc portion 133A, and is formed in a columnar shape with a size that can be inserted inside the third inner peripheral portion 143A of the third step portion 143. . One side surface 133Aa of the disc portion 133A is disposed on the outer peripheral portion of the disc portion 133A. The tertiary lid 133 has a seal groove 133C formed on one side surface 133Aa of the disk portion 133A. A seal member (for example, a rubber O-ring) 133D is inserted into the seal groove 133C. Further, the tertiary lid 133 is provided with a plurality of through holes 133E along the circumferential direction at a position that is an outer peripheral portion of the disc portion 133A and avoids the seal groove 133C. The through hole 133E is provided corresponding to the third lid bolt hole 143C provided in the third seat surface portion 143B of the third step portion 143. The tertiary lid 133 is configured such that the bolt 153 inserted through the through hole 133E is screwed into the third lid bolt hole 143C with one side surface 133Aa of the disc portion 133A facing the third seat surface portion 143B of the third step portion 143. As a result, the side surface 133Aa is tightened so as to be pressed against the third seat surface portion 143B, and the seal member 133D is sandwiched between the one side surface 133Aa side and the third seat surface portion 143B side. The position of the third step portion 143 in the opening 122 is sealed.

  And a radioactive substance is inserted in the basket 114 of the cavity 124 in the trunk | drum 112 in water, and the primary cover 131 is arrange | positioned. Thereafter, the body 112 is pulled up from the water, drained and sucked from a drain port (not shown) provided in the primary lid 131, and after the primary lid 131 is attached with a bolt 151, vacuum drying and primary By injecting gas (for example, inert gas) from a sealing port (not shown) provided in the lid 131, the inside sealed by the primary lid 131 is made negative pressure and filled with gas. Thereafter, the secondary lid 132 and the tertiary lid 133 are attached by bolts 152 and 153. As described above, the radioactive substance is stored in the cask 111 by attaching the primary lid 131, the secondary lid 132, and the tertiary lid 133 to the trunk body 121. Although not clearly shown in the figure, the cask 111 has a configuration having only the primary lid 131 and the secondary lid 132 or a configuration having only the primary lid 131 and the tertiary lid 133.

  In the present embodiment, the primary lid 131 is referred to as an inner lid, and the first lid bolt hole 141C for fixing the primary lid 131 to the body portion 112 is referred to as an inner lid bolt hole. In the present embodiment, the secondary lid 132 and the tertiary lid 133 are referred to as an outer lid for closing the space outside the inner lid, and the second lid 132 and the tertiary lid 133 are fixed to the body portion 112. The two lid bolt holes 142C and the third lid bolt hole 143C are referred to as outer lid bolt holes.

  Hereinafter, the lid bolt hole plug will be described.

  FIG. 4 is a side view of the lid bolt hole plug according to the present embodiment. FIG. 5 is a side view of the use state of the lid bolt hole plug shown in FIG. FIG. 6 is a side view of a modified example of the lid bolt hole plug shown in FIG.

  The lid bolt hole plug 1 shown in FIGS. 4 to 6 is for waterproofing the lid bolt holes 141C, 142C, and 143C when the trunk 112 is submerged when the radioactive material is stored in the cask 111. This is to prevent water from entering the lid bolt holes 141C, 142C, 143C. As shown in FIGS. 4 and 5, the lid bolt hole plug 1 includes an insertion portion 2, a sealing material 3, and a pressing portion 4.

  The insertion portion 2 is formed in a rod shape so as to be inserted into the lid bolt holes 141C, 142C, 143C.

  The sealing material 3 is provided in the insertion portion 2. The sealing material 3 is provided at the insertion end 2A, which is a portion where the insertion portion 2 is inserted into the lid bolt holes 141C, 142C, 143C. The sealing material 3 is formed in an annular shape and disposed along the outer peripheral portion of the insertion end 2 </ b> A of the insertion portion 2 by being disposed so as to pierce the insertion portion 2 therein. In this embodiment, the two sealing materials 3 are arrange | positioned, and as shown in FIG. 4, the mutual outer peripheral part contacts in the rod-shaped extension direction of the insertion part 2, and it is set as the shape which the center side left | separated. The sealing material 3 is formed of ethylene / propylene / diene rubber, nitrile rubber, silicon rubber or the like as a polymer material.

  The pressing part 4 presses the sealing material 3 against the inner surface of the lid bolt holes 141C, 142C, 143C. Specifically, the pressing portion 4 includes a seal material support portion 4A, a moving member 4B, and a movement restricting portion 4C.

  The seal material support portion 4A of the pressing portion 4 is provided at the insertion end 2A for inserting the insertion portion 2 into the lid bolt holes 141C, 142C, 143C. The seal material support portion 4A is a center line CL of the insertion portion 2 extending along the insertion direction (X ′ direction in the figure) that is a rod-like extending direction in the insertion portion 2 and is inserted into the lid bolt holes 141C, 142C, 143C. On the other hand, it is formed in a disc shape so as to protrude in the radial direction centering on the center line CL. The X ′ direction corresponds to the depth direction of the lid bolt holes 141C, 142C, 143C. Further, the sealing material support 4A is not limited to a disk shape, but may be formed as a plurality of protrusions protruding in the radial direction with the center line CL as the center although not clearly shown in the drawing. The sealing material 3 mentioned above is provided along the outer peripheral part in the insertion end 2A of the insertion part 2 by hanging on this sealing material support part 4A.

  The moving member 4B of the pressing portion 4 is formed in a cylindrical shape extending in the insertion direction of the insertion portion 2, is provided so that the insertion portion 2 can be inserted into the cylinder, and is provided so as to be movable in the insertion direction. . The sealing material 3 described above is disposed between one end of the moving member 4B and the sealing material support 4A. Therefore, as shown in FIGS. 5 and 6, when the moving member 4B is moved so as to approach the insertion end 2A of the insertion portion 2, two seals are provided between the movement member 4B and the sealing material support portion 4A. The material 3 is crushed and expanded to the outside. Then, the sealing material 3 whose diameter is expanded outward becomes larger than the inner diameter of the lid bolt holes 141C, 142C, 143C, and as a result, the sealing material 3 is pressed against the inner surfaces of the lid bolt holes 141C, 142C, 143C.

  The movement restricting portion 4 </ b> C of the pressing portion 4 maintains a moving position where the moving member 4 </ b> B approaches the insertion end 2 </ b> A of the insertion portion 2. 4 C of movement control parts are provided in the protrusion end 2B which protrudes outside the cover bolt hole 141C, 142C, 143C when the insertion part 2 is inserted in the cover bolt hole 141C, 142C, 143C. It is arranged so as to be rotatable about an axis 4Ca perpendicular to the axis. Further, the movement restricting portion 4C has a cam portion in which an outer peripheral portion around the shaft 4Ca is eccentric with respect to the shaft 4Ca. In the cam portion, a flat first cam surface 4Cb close to the shaft 4Ca and a flat second cam surface 4Cc far from the shaft 4Ca are provided adjacent to each other in the rotation direction. The movement restricting portion 4C has an operation lever 4Cd for operating rotation around the shaft 4Ca. Accordingly, when the operation lever 4Cd is operated and the movement restricting portion 4C is rotated so that the first cam surface 4Cb close to the shaft 4Ca contacts the other end of the moving member 4B as shown in FIG. Since the other end of the moving member 4B is close, the moving member 4B moves away from the insertion end 2A (sealing material support portion 4A) of the insertion portion 2 due to the elastic force of the sealing material 3, so that the sealing material 3 is inward. Reduce diameter. Since the first cam surface 4Cb is flat and the other end of the moving member 4B is also flat, the contact between the first cam surface 4Cb and the other end of the moving member 4B is maintained. On the other hand, when the operation lever 4Cd is operated and the movement restricting portion 4C is rotated so that the second cam surface 4Cc far from the shaft 4Ca contacts the other end of the moving member 4B, as shown in FIGS. Since the shaft 4Ca and the other end of the moving member 4B are distant from each other, the moving member 4B approaches the insertion end 2A (sealing material support portion 4A) of the insertion portion 2 against the elastic force of the sealing material 3, so that the mutual The sealing material 3 is crushed in between to expand the diameter outward. Since the second cam surface 4Cc is flat and the other end of the moving member 4B is also flat, the contact between the second cam surface 4Cc and the other end of the moving member 4B is maintained.

  The lid bolt hole plug 1 is waterproof to prevent water from entering the lid bolt holes 141C, 142C, 143C by pressing the sealing material 3 against the inner surface of the lid bolt holes 141C, 142C, 143C with such a configuration. It has a function.

  Incidentally, in FIG. 5, the lid bolt hole plug 1 is connected to the first lid bolt hole 141 </ b> C into which the bolt 151 is screwed in order to attach the primary lid 131, which is an inner lid, to the first seat surface portion 141 </ b> B of the first step portion 141. The state where is attached is shown. As described above, the primary lid 131 is disposed on the trunk 112 in the water, and is attached by the bolt 151 after being pulled up from the water. Accordingly, the lid bolt hole plug 1 to be attached to the first lid bolt hole 141C has the insertion portion 2, the seal material 3 and the pressing portion 4 as a whole so that the primary lid 131 can be disposed on the first seat surface portion 141B after being attached. It is configured to be insertable into the through hole 131E of the primary lid 131. In addition, the lid bolt hole plug 1 attached to the first lid bolt hole 141C has a protruding end 2B (moving) of the insertion portion 2 so that the primary lid 131 can be removed from the first lid bolt hole 141C after the primary lid 131 is disposed on the first seat surface portion 141B. The length dimension of the insertion portion 2 is set to a length that the restriction portion 4C) protrudes from the through hole 131E. That is, the insertion portion 2 is formed such that the length dimension L1 extending outside the first lid bolt hole 141C is larger than the length dimension L2 of the through hole 131E of the primary lid 131. The length dimension L1 may be a dimension from one end to the upper side when the moving member 4B moves to a position approaching the insertion end 2A of the insertion portion 2.

  On the other hand, in FIG. 6, the second lid bolt hole 142 </ b> C into which the bolt 152 is screwed to attach the secondary lid 132 that is the outer lid to the first seat surface portion 142 </ b> B of the second step portion 142, or the tertiary that is the outer lid. The state is shown in which the lid bolt hole plug 1 is attached to the third lid bolt hole 143C into which the bolt 153 is screwed in order to attach the lid 133 to the first seat surface portion 143B of the third step portion 143. As described above, the secondary lid 132 and the tertiary lid 133 are disposed on the trunk portion 112 after being pulled up from the water, and are attached by the bolts 152 and 153. Therefore, the lid bolt hole plug 1 attached to the second lid bolt hole 142C and the third lid bolt hole 143C can be inserted into the through hole 132E and the through hole 133E in the entirety of the insertion portion 2, the seal material 3, and the pressing portion 4. There are no constraints to configure. In addition, the lid bolt hole plug 1 attached to the second lid bolt hole 142C or the third lid bolt hole 143C has a dimension L3 corresponding to the length dimension L1 limited to the length dimension L4 of the through holes 132E and 133E. It may be small.

  FIG. 7 is a side view of another example of the lid bolt hole plug according to the present embodiment. FIG. 8 is a side view of the lid bolt hole plug shown in FIG. 7 in use. FIG. 9 is a side view of a modified example of the lid bolt hole plug shown in FIG.

  The lid bolt hole plug 11 shown in FIG. 7 to FIG. 9 is for waterproofing the lid bolt holes 141C, 142C, 143C when the trunk 112 is submerged when the radioactive material is stored in the cask 111. This is to prevent water from entering the lid bolt holes 141C, 142C, 143C. As shown in FIGS. 7 and 8, the lid bolt hole plug 11 includes an insertion portion 12, a seal material 13, and a pressing portion 14.

  The insertion part 12 is formed in a rod shape so as to be inserted into the lid bolt holes 141C, 142C, 143C.

  The sealing material 13 is provided in the insertion portion 12. The sealing material 13 is provided at the insertion end 12A, which is a portion where the insertion portion 12 is inserted into the lid bolt holes 141C, 142C, 143C. The sealing material 13 is formed in an annular shape and disposed along the outer peripheral portion of the insertion end 12 </ b> A of the insertion portion 12 by being disposed so as to pierce the insertion portion 12 therein. In the present embodiment, two sealing members 13 are arranged, and as shown in FIG. 7, the outer peripheral portions are in contact with each other in the rod-like extending direction of the insertion portion 12 and the center side is separated. The sealing material 13 is formed of ethylene, propylene, diene rubber, nitrile rubber, silicon rubber, or the like as a polymer material.

  The pressing part 14 presses the sealing material 13 against the inner surface of the lid bolt holes 141C, 142C, 143C. Specifically, the pressing portion 14 includes a seal material support portion 14A, a moving member 14B, and a movement restricting portion 14C.

  The sealing material support portion 14A of the pressing portion 14 is provided at the insertion end 12A for inserting the insertion portion 12 into the lid bolt holes 141C, 142C, 143C. The seal material support portion 14A is a center line CL of the insertion portion 12 that extends along the insertion direction (X ′ direction in the drawing) that is a rod-like extending direction in the insertion portion 12 and that is inserted into the lid bolt holes 141C, 142C, 143C. On the other hand, it is formed in a disc shape so as to protrude in the radial direction centering on the center line CL. The X ′ direction corresponds to the depth direction of the lid bolt holes 141C, 142C, 143C. Further, the sealing material support portion 14A is not limited to a disk shape, but may be formed as a plurality of protrusions protruding in the radial direction with the center line CL as the center, though not explicitly shown in the drawing. The sealing material 13 described above is provided along the outer peripheral portion of the insertion end 12A of the insertion portion 12 by being hooked on the sealing material support portion 14A.

  The moving member 14B of the pressing portion 14 is formed in a cylindrical shape extending in the insertion direction of the insertion portion 12, is provided so that the insertion portion 12 can be inserted into the cylinder, and is provided so as to be movable in the insertion direction. . The sealing material 13 described above is disposed between one end of the moving member 14B and the sealing material support portion 14A. Therefore, as shown in FIGS. 8 and 9, when the moving member 14B is moved so as to approach the insertion end 12A of the insertion portion 12, two seals are provided between the movement member 14B and the sealing material support portion 14A. The material 13 is crushed and expanded to the outside. Then, the sealing material 13 whose diameter is expanded outward becomes larger than the inner diameter of the lid bolt holes 141C, 142C, and 143C. As a result, the sealing material 13 is pressed against the inner surfaces of the lid bolt holes 141C, 142C, and 143C. The other end of the moving member 14B is provided with a hemispherical operation piece 14Ba for performing an extrusion operation.

  The movement restricting portion 14 </ b> C of the pressing portion 14 maintains a moving position where the moving member 14 </ b> B approaches the insertion end 12 </ b> A of the insertion portion 12. The movement restricting portion 14C has a protruding end 12B that protrudes outside the cover bolt holes 141C, 142C, and 143C when the moving member 14B is penetrated and the insertion portion 12 is inserted into the cover bolt holes 141C, 142C, and 143C. Is provided. The movement restricting portion 14C is in a locked state (see FIGS. 8 and 9) in which the moving member 14B maintains the moving position approaching the insertion end 12A in response to the pushing operation toward the insertion end 12A in the moving member 14B, and the movement member 14B. Has an alternate type latch mechanism that switches between a release state (see FIG. 7) that releases the maintenance of the moving position approaching the insertion end 12A. In addition, although the alternate type latch mechanism is not clearly shown in the drawings, there are a heart cam type method, a rotating cam type, a ratchet cam type, and the like, which are indicated by a rectangular outer mold in each figure. Accordingly, when the operation piece 14Ba of the moving member 14B is pushed and the latch mechanism of the movement restricting portion 14C is released, the moving member 14B is inserted into the insertion portion 12 by the elastic force of the sealing material 13 as shown in FIG. In order to move away from the insertion end 12A (sealing material support portion 14A), the sealing material 13 is reduced in diameter. On the other hand, when the operation piece 14Ba of the moving member 14B is pushed and the latch mechanism of the movement restricting portion 14C is locked, the moving member 14B is subjected to the elastic force of the sealing material 13 as shown in FIGS. Accordingly, in order to approach the insertion end 12A (seal material support portion 14A) of the insertion portion 12, the seal material 13 is crushed between each other to expand the diameter outward.

  The lid bolt hole plug 11 is waterproof to prevent water from entering the lid bolt holes 141C, 142C, 143C by pressing the sealing material 13 against the inner surface of the lid bolt holes 141C, 142C, 143C with such a configuration. It has a function.

  By the way, in FIG. 8, in order to attach the primary lid 131 which is an inner lid to the first seat surface portion 141B of the first step portion 141, the lid bolt hole plug 11 is connected to the first lid bolt hole 141C into which the bolt 151 is screwed. The state where is attached is shown. As described above, the primary lid 131 is disposed on the trunk 112 in the water, and is attached by the bolt 151 after being pulled up from the water. Accordingly, the lid bolt hole plug 11 to be attached to the first lid bolt hole 141C has the insertion portion 12, the seal member 13, and the pressing portion 14 as a whole so that the primary lid 131 can be disposed on the first seat surface portion 141B after being attached. It is configured to be insertable into the through hole 131E of the primary lid 131. In addition, the lid bolt hole plug 11 attached to the first lid bolt hole 141C has a protruding end 12B (movement) of the insertion portion 12 so that the primary lid 131 can be removed from the first lid bolt hole 141C after the primary lid 131 is disposed on the first seat surface portion 141B. The length dimension of the insertion portion 12 is set to a length that the restricting portion 14C) protrudes from the through hole 131E. That is, the insertion portion 12 is formed such that the length dimension L1 extending outside the first lid bolt hole 141C is larger than the length dimension L2 of the through hole 131E of the primary lid 131. The length dimension L1 may be a dimension from one end to the upper side when the moving member 14B moves to a position approaching the insertion end 12A of the insertion portion 12.

  On the other hand, in FIG. 9, the second lid bolt hole 142 </ b> C into which the bolt 152 is screwed in order to attach the secondary lid 132 that is the outer lid to the first seat surface portion 142 </ b> B of the second step portion 142, or the tertiary that is the outer lid. The state where the lid bolt hole plug 11 is attached to the third lid bolt hole 143C into which the bolt 153 is screwed in order to attach the lid 133 to the first seat surface portion 143B of the third step portion 143 is shown. As described above, the secondary lid 132 and the tertiary lid 133 are disposed on the trunk portion 112 after being pulled up from the water, and are attached by the bolts 152 and 153. Accordingly, the lid bolt hole plug 11 attached to the second lid bolt hole 142C and the third lid bolt hole 143C can be inserted into the through hole 132E and the through hole 133E in the entirety of the insertion portion 12, the seal material 13, and the pressing portion 14. There are no constraints to configure. In addition, the lid bolt hole plug 11 attached to the second lid bolt hole 142C or the third lid bolt hole 143C has a dimension L3 corresponding to the length dimension L1 limited to the length dimension L4 of the through holes 132E and 133E. It may be small.

  FIG. 10 is a side view of another example of the lid bolt hole plug according to the present embodiment. FIG. 11 is a side view of the cover bolt hole plug shown in FIG. 10 in use. 12 is a side view of a modified example of the lid bolt hole plug shown in FIG.

  The lid bolt hole plug 21 shown in FIGS. 10 to 12 is used for waterproofing the lid bolt holes 141C, 142C, and 143C when the trunk 112 is submerged when the radioactive substance is stored in the cask 111. This is to prevent water from entering the lid bolt holes 141C, 142C, 143C. As shown in FIGS. 10 and 11, the lid bolt hole plug 21 includes an insertion portion 22, a sealing material 23, and a pressing portion 24.

  The insertion portion 22 is formed in a rod shape and is provided so as to be inserted into the lid bolt holes 141C, 142C, 143C.

  The sealing material 23 is provided in the insertion portion 22. The sealing material 23 is provided at the insertion end 22A, which is a portion where the insertion portion 22 is inserted into the lid bolt holes 141C, 142C, 143C. The seal member 23 is formed in an annular shape and disposed along the outer peripheral portion of the insertion end 22 </ b> A of the insertion portion 22 by being arranged to pierce the insertion portion 22 therein. In this embodiment, the two sealing materials 23 are arrange | positioned, and as shown in FIG. 10, the mutual outer peripheral part contacts in the rod-shaped extension direction of the insertion part 22, and it is set as the shape which the center side left | separated. The sealing material 23 is formed of ethylene, propylene, diene rubber, nitrile rubber, silicon rubber, or the like as a polymer material.

  The pressing part 24 presses the sealing material 23 against the inner surface of the lid bolt holes 141C, 142C, 143C. Specifically, the pressing portion 24 includes a seal material support portion 24A, a moving member 24B, and a movement restricting portion 24C.

  The seal material support portion 24A of the pressing portion 24 is provided at the insertion end 22A for inserting the insertion portion 22 into the lid bolt holes 141C, 142C, 143C. The sealing material support portion 24A is a bar-shaped extending direction in the insertion portion 22, and is a center line CL of the insertion portion 22 extending along the insertion direction (X ′ direction in the drawing) to be inserted into the lid bolt holes 141C, 142C, 143C. On the other hand, it is formed in a disc shape so as to protrude in the radial direction centering on the center line CL. The X ′ direction corresponds to the depth direction of the lid bolt holes 141C, 142C, 143C. Further, the sealing material support portion 24A is not limited to a disk shape, but may be formed as a plurality of protrusions protruding in the radial direction with the center line CL as the center although not clearly shown in the drawing. The sealing material 23 described above is provided along the outer peripheral portion of the insertion end 22A of the insertion portion 22 by being hooked on the sealing material support portion 24A.

  The moving member 24B of the pressing portion 24 is formed in a cylindrical shape extending in the insertion direction of the insertion portion 22, is provided so that the insertion portion 22 can be inserted into the cylinder, and is provided so as to be movable in the insertion direction. . The sealing material 23 described above is disposed between one end of the moving member 24B and the sealing material support 24A. Therefore, as shown in FIGS. 11 and 12, when the moving member 24B is moved so as to approach the insertion end 22A of the insertion portion 22, two seals are provided between the movement member 24B and the sealing material support portion 24A. The material 23 is crushed and expanded outward. Then, the sealing material 23 whose diameter is increased outwardly becomes larger than the inner diameter of the lid bolt holes 141C, 142C, 143C. As a result, the sealing material 23 is pressed against the inner surfaces of the lid bolt holes 141C, 142C, 143C.

  The movement restricting portion 24 </ b> C of the pressing portion 24 maintains a moving position where the moving member 24 </ b> B approaches the insertion end 22 </ b> A of the insertion portion 22. The movement restricting portion 24C is provided at a protruding end 22B that protrudes outside the lid bolt holes 141C, 142C, 143C when the insertion portion 22 is inserted into the lid bolt holes 141C, 142C, 143C. The movement restricting portion 24 </ b> C is formed in a cylindrical shape extending in the insertion direction of the insertion portion 22, and is provided so that the insertion portion 22 can be inserted into the cylinder. The movement restricting portion 24C is formed with a female screw 24Ca on its inner surface, screwed into a male screw 22C formed on the protruding end 22B portion of the insertion portion 22, and provided rotatably around the insertion portion 22. A rotating member that moves in the extending direction of the insertion portion 22 in accordance with the rotating operation is formed. The movement restricting portion 24C is provided so as to contact the moving member 24B. Accordingly, when the rotation-controlled movement restricting portion 24C moves away from the insertion end 22A, the moving member 24B is inserted into the insertion end 22A (sealing material support portion 24A of the insertion portion 22 by the elastic force of the sealing material 23 as shown in FIG. ), The diameter of the sealing material 23 is reduced inward. On the other hand, when the rotationally controlled movement restricting portion 24C approaches the insertion end 22A, the moving member 24B resists the elastic force of the seal member 23 as shown in FIGS. 11 and 12, and the insertion end 22A of the insertion portion 22 is inserted. In order to approach (seal material support part 24A), the seal material 23 is crushed between each other to expand the outside diameter.

  The lid bolt hole plug 21 is waterproof to prevent water from entering the lid bolt holes 141C, 142C, and 143C by pressing the sealing material 23 against the inner surface of the lid bolt holes 141C, 142C, and 143C with such a configuration. It has a function.

  By the way, in FIG. 11, in order to attach the primary lid 131 which is an inner lid to the first seat surface portion 141B of the first step portion 141, the lid bolt hole plug 21 is inserted into the first lid bolt hole 141C into which the bolt 151 is screwed. The state where is attached is shown. As described above, the primary lid 131 is disposed on the trunk 112 in the water, and is attached by the bolt 151 after being pulled up from the water. Accordingly, the lid bolt hole plug 21 to be attached to the first lid bolt hole 141C has the insertion portion 22, the seal member 23, and the pressing portion 24 as a whole so that the primary lid 131 can be disposed on the first seat surface portion 141B after being attached. It is configured to be insertable into the through hole 131E of the primary lid 131. Moreover, the lid bolt hole plug 21 attached to the first lid bolt hole 141C has a protruding end 22B (movement) of the insertion portion 22 so that the primary lid 131 can be removed from the first lid bolt hole 141C after the primary lid 131 is disposed on the first seat surface portion 141B. The length dimension of the insertion portion 22 is set to a length that the restriction portion 24C) protrudes from the through hole 131E. In other words, the insertion portion 22 is formed such that the length dimension L1 extending outside the first lid bolt hole 141C is larger than the length dimension L2 of the through hole 131E of the primary lid 131. The length dimension L1 may be a dimension from one end to the upper side when the movement restricting portion 24C moves to a position approaching the insertion end 22A of the insertion portion 22.

  On the other hand, in FIG. 12, the second lid bolt hole 142C into which the bolt 152 is screwed in order to attach the secondary lid 132 as the outer lid to the first seat surface portion 142B of the second step portion 142, or the tertiary as the outer lid. A state in which the lid bolt hole plug 21 is attached to the third lid bolt hole 143C into which the bolt 153 is screwed in order to attach the lid 133 to the first seat surface portion 143B of the third step portion 143 is shown. As described above, the secondary lid 132 and the tertiary lid 133 are disposed on the trunk portion 112 after being pulled up from the water, and are attached by the bolts 152 and 153. Therefore, the lid bolt hole plug 21 attached to the second lid bolt hole 142C and the third lid bolt hole 143C can be inserted into the through hole 132E and the through hole 133E in the entirety of the insertion portion 22, the sealing material 23, and the pressing portion 24. There are no constraints to configure. In addition, the lid bolt hole plug 21 attached to the second lid bolt hole 142C or the third lid bolt hole 143C has a dimension L3 corresponding to the length dimension L1 limited to the length dimension L4 of the through holes 132E and 133E. It may be small.

  FIG. 13 is a process diagram of the radioactive substance storage method using the lid bolt hole plug according to the present embodiment. FIG. 14 is a side view of another example of the radioactive substance storage method using the lid bolt hole plug according to the present embodiment. 13 and 14 show the radioactive substance storage method using the above-described lid bolt hole plug 1, the lid bolt hole plugs 11 and 21 may be used.

  First, outside the pool, the lid bolt hole plug 1 is attached to the first lid bolt hole 141C, the second lid bolt hole 142C, and the third lid bolt hole 143C in the trunk portion 112 of the cask 111 (see FIGS. 5 and 6). .

  Next, as shown in FIG. 13A, the trunk 112 is submerged in the pool water.

  Next, the radioactive material is stored in the trunk 112 in the water of the pool. Next, as shown in FIG. 13B, a primary lid 131 is disposed on the trunk 112 in the pool water.

  Next, the trunk portion 112 is pulled up from the pool. Here, the water in the trunk portion 112 is sucked so that the water level is lower than the primary lid 131.

  Next, as shown in FIG. 13C, the lid bolt hole plug 1 is removed. Here, the lid bolt hole plug 1 attached to the second lid bolt hole 142C and the third lid bolt hole 143C is removed in the same manner. Thereafter, the body 112 is drained.

  Next, as shown in FIG. 13D, the primary lid 131 is fastened and fixed with bolts 151. After that, the inside of the trunk 112, which is the inside of the primary lid 131, is vacuum-dried and filled with an inert gas. Then, the secondary lid 132 and the tertiary lid 133 are fastened and fixed with bolts 152 and 153.

  In addition, when attaching the lid bolt hole plug 1 to the first lid bolt hole 141C in the trunk portion 112 of the cask 111 outside the pool, as shown in FIG. 14, a plurality of arbitrarily selected locations of the first lid bolt hole 141C ( The guide pins 10 extending from the first lid bolt hole 141 </ b> C with a longer dimension than the lid bolt hole plug 1 may be attached to four or the like at approximately equal intervals on the circumference. The guide pin 10 is formed to taper toward the extension extending from the first lid bolt hole 141C. Further, the guide pin 10 has a male screw 10A that is screwed into the first lid bolt hole 141C. Further, when the guide pin 10 is attached to the first lid bolt hole 141C, an annular sealing material 10B that contacts the inner surface of the first lid bolt hole 141C is disposed around the guide pin 10. When the primary lid 131 is arranged with respect to the trunk portion 112 in the pool water, the guide pin 10 is first inserted into the through hole 131E to guide the arrangement of the primary lid 131. And the guide pin 10 is removed together in the process of removing the lid bolt hole plug 1.

  Moreover, each lid bolt hole 141C, 142C, 143C has an opening peripheral surface 141Ca, 142Ca, 143Ca that is smooth without an unevenness on the inner surface of the opening and has a larger diameter than the female screw portion. In the step of attaching the lid bolt hole plugs 1, 11 and 21 to the lid bolt holes 141C, 142C and 143C in 112, the sealing materials 3, 13 of the lid bolt hole plugs 1, 11 and 21 are attached to the opening peripheral surfaces 141Ca, 142Ca and 143Ca. , 23 are arranged. That is, the sealing materials 3, 13, and 23 do not have unevenness and are in contact with the smooth opening peripheral surfaces 141 Ca, 142 Ca, and 143 Ca by expanding the diameter.

  FIG. 15 is a side view of another example of the lid bolt hole plug according to the present embodiment. 16 is a side view showing the operation of the lid bolt hole plug shown in FIG. 15 and 16, the above-described lid bolt hole plug 1 is the basic configuration, but the lid bolt hole plugs 11 and 21 may be used as the basic configuration.

  In the lid bolt hole plug 1 shown in FIGS. 15 and 16, the insertion portion 2 has a wiping member 5 at the insertion end 2A. In this embodiment, the wiping member 5 is attached to the tip of the seal material support 4A, and the lid bolt hole plug 1 is brought into contact with the inner surface of the first lid bolt hole 141C and the inner surface of the through hole 131E of the primary lid 131. It is formed in a disk shape so that The wiping member 5 is formed of a material that can absorb moisture. The wiping member 5 wipes off moisture remaining in the opening of the first lid bolt hole 141C and the through hole 131E of the primary lid 131 when the lid bolt hole plug 1 is removed. As shown in FIG. 16, when the inner diameter of the through hole 131E of the primary lid 131 is larger than the first lid bolt hole 141C, the wiping member 5 penetrates the inner surface of the first lid bolt hole 141C and the primary lid 131. In order to be able to contact the inner surface of the hole 131E, it is preferable to have elasticity so as to bulge outward in the radial direction.

  FIG. 17 is a plan view of another example of the lid bolt hole plug according to the present embodiment. 18 is a side view of the lid bolt hole plug shown in FIG. 17 and 18, the lid bolt hole plug 11 described above is the basic configuration, but the lid bolt hole plug 21 may be used as the basic configuration.

  The lid bolt hole plug 11 shown in FIGS. 17 and 18 is inserted into the second lid bolt hole 142C and the third lid bolt hole 143C, which are outer lid bolt holes, and is attached to a plurality of adjacent outer lid bolt holes. And a connecting portion 6 for connecting a plurality of lid bolt hole plugs 11 to be connected. In FIG. 17 and FIG. 18, the connecting part 6 is connected to the first connecting part 6A for connecting the moving member 14B and the movement restricting part 14C of each lid bolt hole plug 11 and the moving member 14B in place of the operation piece 14Ba. Two connecting portions 6B. In addition, the movement restricting portion 14 </ b> C of each lid bolt hole plug 11 may be connected. Although not clearly shown in the drawing, the connecting portion applied to the lid bolt hole plug 21 connects the moving member 24B. Accordingly, the lid bolt hole plugs 11 connected by the connecting portion 6 are attached together to a plurality of adjacent outer lid bolt holes.

  FIG. 19 is a side view of another example of the lid bolt hole plug according to the present embodiment. In FIG. 19, the above-described lid bolt hole plug 1 has a basic configuration, but the lid bolt hole plugs 11 and 21 may be used as the basic configuration.

  The lid bolt hole plug 1 shown in FIG. 19 has a base portion 7 that extends from the insertion end 2 </ b> A of the insertion portion 2. The base portion 7 is inserted into the inner portion of the first lid bolt hole 141C while reaching the inner portion of the first lid bolt hole 141C. In the present embodiment, the base portion 7 has a core portion 7A that is attached to the tip of the sealing material support portion 4A and is inserted into the hollow portion 2C formed in the insertion portion 2. The core portion 7A reinforces the insertion portion 2. Then, the base 7 is disposed at a position where the lid bolt hole plug 1 is stably installed at a position where it is inserted into the inner portion of the first lid bolt hole 141C, and the sealing material 3 is in contact with the opening peripheral surface 141Ca. To do.

  As described above, the lid bolt hole plug 1 (11, 21) of the present embodiment includes the body portion 112 having the opening portion 122 formed in the upper portion and the lower portion closed by the bottom portion 123, and the opening portion 122 of the body portion 112. Cask as a radioactive substance storage container having lid parts 131, 132, 133 fixed by tightening bolts 151, 152, 153 in lid bolt holes 141C, 142C, 143C formed in opening 122 in a closed manner 111, the insertion portion 2 (12, 22) inserted into the lid bolt holes 141C, 142C, 143C in order to waterproof the lid bolt holes 141C, 142C, 143C when the radioactive material is stored in the body portion 112. The sealing material 3 (1) provided along the outer peripheral portion of the portion where the insertion portion 2 (12, 22) is inserted into the lid bolt holes 141C, 142C, 143C. , 23) and the pressing portion 4 (14, 24) that presses the sealing material 3 (13, 23) against the inner surface of the lid bolt holes 141C, 142C, 143C regardless of the female screw portions of the lid bolt holes 141C, 142C, 143C. And comprising.

  According to the lid bolt hole plug 1 (11, 21), the sealing material 3 (13, 23) is attached to the inner surface of the lid bolt holes 141C, 142C, 143C regardless of the female screw portions of the lid bolt holes 141C, 142C, 143C. Since the waterproof function can be obtained in a short time by providing the pressing portion 4 (14, 24) that presses against the lid, it is easy to perform the work of waterproofing or removing the lid bolt holes 141C, 142C, 143C of the cask 111. It can be carried out.

  Further, in the lid bolt hole plug 1 (11, 21) of the present embodiment, the pressing portion 4 (14, 24) is provided at the insertion end 2A (12A, 22A) of the insertion portion 2 (12, 22) and sealed. The sealant support part 4A (14A, 24A) that supports the material 3 (13, 23) and the insertion part 2 (12, 22) can move along the insertion direction of the insertion part 2 (12, 22). A moving member 4B (14B, 24B) that is provided and expands the diameter of the sealing material 3 (13, 23) to the outside with the sealing material support portion 4A (14A, 24A) in the movement approaching the insertion end 2A (12A, 22A). ) And a movement restricting portion 4C (14C, 24C) that maintains a moving position where the moving member 4B (14B, 24B) approaches the insertion end 2A (12A, 22A).

  According to the lid bolt hole plug 1 (11, 21), the waterproof function can be obtained in a short time, and the lid bolt holes 141C, 142C, 143C of the cask 111 are waterproofed or removed. Can be easily performed.

  Further, in the lid bolt hole plug 1 of the present embodiment, the movement restricting portion 4C is provided in a portion where the insertion portion 2 extends from the lid bolt holes 141C, 142C, 143C, and pushes the moving member 4B toward the insertion end 2A. Cam portions 4Cb and 4Cc are provided.

  According to the lid bolt hole plug 1, by having the cam portions 4Cb and 4Cc, it is possible to realize an operation of maintaining the moving position where the moving member 4B approaches the insertion end 2A.

  Further, in the lid bolt hole plug 11 of the present embodiment, the movement restricting portion 14C is in a locked state in which the moving member 14B maintains the moving position approaching the insertion end 12A in response to the pushing operation toward the insertion end 12A in the moving member 14B. And an alternate type latch mechanism that switches between a release state in which the moving member 14B releases the maintenance of the moving position approaching the insertion end 12A.

  According to the lid bolt hole plug 11, switching between the locked state and the released state can be easily performed, and the work of performing waterproofing or removing of the lid bolt holes 141 </ b> C, 142 </ b> C, 143 </ b> C of the cask 111 is easy. It is possible to obtain a remarkable effect.

  Further, in the lid bolt hole plug 21 of the present embodiment, the movement restricting portion 24C is provided so as to be rotatable around the insertion portion 22 by screwing, and a rotating member that pushes the moving member 24B to the insertion end 22A side by a rotating operation. Make.

  According to the lid bolt hole plug 21, the moving member 24 </ b> B is pushed out toward the insertion end 22 </ b> A by a rotation operation, thereby realizing an operation of maintaining the moving position where the moving member 24 </ b> B approaches the insertion end 22 </ b> A.

  Further, in the lid bolt hole plug 1 (11, 21) of the present embodiment, the insertion portion 2 (12, 22) has the wiping member 5 at the insertion end 2A (12A, 22A).

  According to the lid bolt hole plug 1 (11, 21), when the lid bolt hole plug 1 (11, 21) is removed, the wiping member 5 opens or covers the lid bolt holes 141C, 142C, 143C. Moisture remaining in the through holes 131E, 132E, 133E of 131, 132, 133 can be wiped off.

  In the lid bolt hole plug 1 (11, 21) of the present embodiment, the lid bolt holes 141C, 142C, 142C are provided extending from the insertion end 2A (12A, 22A) of the insertion portion 2 (12, 22). The base 7 is inserted into the inner part of 143C while reaching the inner part of the lid bolt holes 141C, 142C, 143C.

  According to the lid bolt hole plug 1 (11, 21), the base 7 can be stably installed in the lid bolt holes 141C, 142C, 143C, and the sealing material 3 (13, 23) can be placed on the opening peripheral surfaces 141Ca, 142Ca. , 143Ca can be arranged at a position in contact with it.

  In the lid bolt hole plug 1 (11, 21) of the present embodiment, the lid portion closes the primary lid 131 that is an inner lid that closes the opening portion 122 of the body portion 112 and the space outside the primary lid 131. A plurality of through holes 131E, 132E, 133E that pass through the bolts 151, 152, 153 to the primary lid 131, the secondary lid 132, and the tertiary lid 133. The insertion portion 2 (12, 22), the sealing material 3 (13, 23), and the pressing portion 4 (14, 24) are provided so as to be inserted into the through hole 131E of the primary lid 131 and are inserted. The portion 2 (12, 22) is formed such that the length dimension L1 extending outside the lid bolt holes 141C, 142C, 143C is larger than the length dimension L2 of the through hole 131E of the primary lid 131.

  According to the lid bolt hole plug 1 (11, 21), since the primary lid 131 is disposed on the trunk 112 in the pool water, the insertion portion 2 (12, 22) and the sealing material 3 (13, 23) And the pressing part 4 (14, 24) is formed so that it can be inserted into the through hole 131E of the primary lid 131, so that the primary lid 131 can be arranged without interfering with these configurations. Moreover, since the insertion portion 2 (12, 22) is formed such that the length dimension L1 extending outside the first lid bolt hole 141C is larger than the length dimension L2 of the through hole 131E of the primary lid 131, After pulling up the trunk portion 112 from the pool water, the primary lid 131 can be easily taken out from the through hole 131E.

  In the lid bolt hole plug 1 (11, 21), the lid is a primary lid 131 that is an inner lid that closes the opening 122 of the body portion 112, and an outer lid that closes the space outside the primary lid 131. The body portion 112 has a secondary lid 132 and a tertiary lid 133, and the body 112 has a plurality of first lid bolt holes 141 </ b> C for fixing the primary lid 131 by tightening the bolts 151, and the secondary lid 132 and the tertiary lid 133. Has a plurality of second lid bolt holes 142C and a third lid bolt hole 143C for fastening and fixing the bolts 152, 153, and is used for the second lid bolt hole 142C and the third lid bolt hole 143C. It has the connection part 6 which connects two or more.

  According to this lid bolt hole plug 1 (11, 21), it can be attached to the plurality of second lid bolt holes 142C and the third lid bolt holes 143C by being connected by the connecting portion 6.

  The radioactive substance storage method of the present embodiment is formed in the opening portion 122 in such a manner that the opening portion 122 is formed in the upper portion and the lower portion is closed by the bottom portion 123, and the opening portion 122 of the body portion 112 is closed. A primary lid 131 fixed by tightening the bolt 151 in the first lid bolt hole 141C, and a second lid bolt hole 142C or a third lid bolt formed in the opening 122 in a manner to close the space outside the primary lid 131. In the method of storing radioactive material in the cask 111 as the radioactive material storage container having the secondary lid 132 and the tertiary lid 133 fixed by tightening the bolts 152 and 153 in the hole 143C, the outside of the pool is used. In the first lid bolt hole 141C, the second lid bolt hole 142C and the third lid bolt hole 143C in the body portion 112, the lid bolt hole plug 1 (1 21), a step of sinking the trunk 112 in the pool water, a step of storing radioactive material in the trunk 112 in the pool water, and a primary lid 131 for the trunk 112 in the pool water. A step of placing, a step of pulling up the body portion 112 from the pool, a step of removing the lid bolt hole plug 1 (11, 21), a step of draining the inside of the body portion 112, and fixing the primary lid 131 by bolting. A step of vacuum-drying the inside of the body portion 112 inside the primary lid 131 and filling with an inert gas, and a step of bolting and fixing the secondary lid 132 or the tertiary lid 133.

  According to this radioactive substance storage method, in the lid bolt hole plug 1 (11, 21), the sealing material 3 (13, 23) is attached to the lid bolt hole 141C regardless of the female screw portions of the lid bolt holes 141C, 142C, 143C. , 142C, 143C is provided with a pressing portion 4 (14, 24) to be pressed against the inner surface, so that a waterproof function can be obtained in a short time. Therefore, the lid bolt holes 141C, 142C, 143C of the cask 111 are waterproofed or removed. Can be easily performed. As a result, the working time for storing the radioactive substance can be shortened.

  Moreover, in the radioactive substance storage method of this embodiment, the process of attaching the lid bolt hole plug 1 (11, 21) to the first lid bolt hole 141C and the second lid bolt hole 142C or the third lid bolt hole 143C in the trunk portion 112. The guide pin 10 extending from the first lid bolt hole 141C with a length longer than the lid bolt hole plug 1 (11, 21) is attached to a plurality of arbitrarily selected locations of the first lid bolt hole 141C. In the process of removing the plug 1 (11, 21), the guide pin 10 is removed together with the lid bolt hole plug 1 (11, 21).

  According to this radioactive substance storage method, the guide pin 10 is used to prevent the primary lid 131 from interfering with the lid bolt hole plug 1 (11, 21) in the operation of installing the primary lid 131 on the body portion 112. The waterproof function by the lid bolt hole plug 1 (11, 21) can be maintained.

  Moreover, in the radioactive substance storage method of the present embodiment, the inner surface of the opening of the first lid bolt hole 141C and the second lid bolt hole 142C or the third lid bolt hole 143C is smooth and has an internal thread portion. The outer peripheral surfaces 141Ca, 142Ca, 143Ca having a larger diameter than the first cover bolt hole 141C and the second cover bolt hole 142C or the third cover bolt hole 143C in the body 112 are connected to the cover bolt hole plug 1 (11, 11). In the step of attaching 21), the sealing material 3 (13, 23) of the lid bolt hole plug 1 (11, 21) is disposed on the opening peripheral surfaces 141Ca, 142Ca, 143Ca.

  According to this radioactive substance storage method, the sealing material 3 (13, 23) is arranged on the smooth opening peripheral surfaces 141Ca, 142Ca, 143Ca without unevenness, so that the lid bolt hole plug 1 (11, 21) is used. The waterproof function can be improved.

DESCRIPTION OF SYMBOLS 1 Cover bolt hole plug 2 Insertion part 2A Insertion end 2B Projection end 2C Hollow part 3 Sealing material 4 Pushing part 4A Sealing material support part 4B Moving member 4C Movement control part 4Ca Shaft 4Cb First cam surface (cam part)
4Cc Second cam surface (cam part)
4Cd Operation lever 11 Lid bolt hole plug 12 Insertion part 12A Insertion end 12B Projection end 13 Sealing material 14 Pushing part 14A Sealing material support part 14B Moving member 14Ba Operation piece 14C Movement restricting part 21 Lid bolt hole plug 22 Insertion part 22A Insertion end 22B Protruding end 22C Male screw 23 Sealing material 24 Pressing portion 24A Sealing material supporting portion 24B Moving member 24C Movement restricting portion 24Ca Female screw 5 Wiping member 6 Connecting portion 6A First connecting portion 6B Second connecting portion 7 Base portion 7A Core portion 10 Guide Pin 111 cask (radioactive substance storage container)
112 trunk portion 113 lid portion 122 opening portion 123 bottom portion 131 primary lid (inner lid)
131E Through hole 132 Secondary lid (outer lid)
132E Through hole 133 Tertiary lid (outer lid)
133E Through-hole 141C First lid bolt hole (inner lid bolt hole)
141Ca Opening peripheral surface 142C Second lid bolt hole (outer lid bolt hole)
142Ca Opening peripheral surface 143C Third lid bolt hole (outer lid bolt hole)
143Ca Opening surface 151,152,153 Bolt

Claims (12)

An upper portion formed with an opening at the top and a lower portion closed at the bottom, and a lid portion fixed by tightening a bolt into a lid bolt hole formed in the opening in a manner to close the opening of the barrel portion For the radioactive substance storage container having the above, in the lid bolt hole plug of the radioactive substance storage container for waterproofing the lid bolt hole when the radioactive substance is stored in the trunk part,
An insertion portion to be inserted into the lid bolt hole;
A sealing material provided along an outer peripheral portion of a portion where the insertion portion is inserted into the lid bolt hole;
A pressing portion that presses the sealing material against the inner surface of the lid bolt hole regardless of the female screw portion of the lid bolt hole;
A lid bolt hole plug for a radioactive substance storage container. The pressing portion is
A seal material support portion provided at an insertion end of the insert portion to support the seal material;
A moving member provided to be movable along the insertion direction of the insertion portion with respect to the insertion portion, and for expanding the diameter of the sealing material to the outside with the sealing material support portion in a movement approaching the insertion end;
A movement restricting portion for maintaining a moving position where the moving member approaches the insertion end;
The lid bolt hole plug of the radioactive substance storage container according to claim 1, comprising:   The radioactive substance according to claim 2, wherein the movement restricting portion includes a cam portion that is provided in a portion where the insertion portion extends from the lid bolt hole and pushes the moving member toward the insertion end. Storage container lid bolt hole plug.   The movement restricting portion includes a locked state in which the moving member maintains a moving position in which the moving member approaches the insertion end and a moving position in which the moving member approaches the insertion end in response to an operation of pushing the moving member toward the insertion end. 3. The lid bolt hole plug of the radioactive substance storage container according to claim 2, further comprising an alternate type latch mechanism for switching between a release state for releasing the maintenance of the radioactive material storage container.   The said movement control part is provided so that it can rotate centering | focusing on the said insertion part by screwing, and makes the rotation member which pushes out the said movement member to the said insertion end side by rotation operation. Lid bolt hole plug for radioactive material storage container.   The said insertion part has a wiping member in the insertion end, The lid bolt hole plug of the radioactive substance storage container as described in any one of Claims 1-5 characterized by the above-mentioned.   The base part which is extended from the insertion end of the insertion part and is provided to reach the back part of the lid bolt hole while being attached to the inner surface of the lid bolt hole. A lid bolt hole plug of the radioactive substance storage container according to claim 1. The lid portion has an inner lid that closes the opening of the body portion and an outer lid that closes a space outside the inner lid, and penetrates the bolt through the inner lid and the outer lid. There are multiple holes,
The insertion portion, the seal material, and the pressing portion are formed so as to be able to be inserted into the through hole of the inner lid, and the insertion portion has a length dimension that extends to the outside of the lid bolt hole. The lid bolt hole plug of the radioactive substance storage container according to any one of claims 1 to 7, wherein the plug is formed larger than a length dimension of the through hole of the lid. The lid portion includes an inner lid that closes the opening of the body portion and an outer lid that closes a space outside the inner lid, and the body portion fixes the inner lid by tightening a bolt. A plurality of inner lid bolt holes, and a plurality of outer lid bolt holes for fastening the outer lid by tightening the bolts,
The lid bolt hole plug of the radioactive substance storage container according to claim 1, further comprising a connecting portion that connects a plurality of parts used for each of the outer lid bolt holes. A body part having an opening formed in the upper part and a lower part closed at the bottom, and an inner cover fixed by tightening a bolt into an inner cover bolt hole formed in the opening part in a manner to close the opening part of the body And a radioactive substance storage container having an outer cover fixed by tightening a bolt into an outer cover bolt hole formed in the opening in a manner to close the space outside the inner cover. In the radioactive material storage method of storing the radioactive material in
The step of attaching the lid bolt hole plug of the radioactive substance storage container according to any one of claims 1 to 9 to the inner lid bolt hole and the outer lid bolt hole in the trunk portion outside the pool;
Submerging the trunk into the pool water;
Storing the radioactive substance in the trunk in the water of the pool;
Disposing the inner lid with respect to the trunk in the pool water;
A step of lifting the trunk from the pool;
Removing the lid bolt hole plug;
Draining the body part;
Fixing the inner lid by bolting; and
A step of vacuum drying the inside of the body portion which is the inside of the inner lid, and filling with an inert gas;
Fixing the outer lid by bolting; and
The radioactive substance storage method characterized by including.   In the step of attaching the lid bolt hole plug to the inner lid bolt hole and the outer lid bolt hole in the trunk portion, the inner lid bolt hole is longer than the lid bolt hole plug at a plurality of arbitrarily selected locations. 11. The radioactive substance storage method according to claim 10, wherein in the step of attaching a guide pin extending from a lid bolt hole and removing the lid bolt hole plug, the guide pin is removed together with the lid bolt hole plug.   The inner surface of the opening portion of the lid bolt hole is smooth without any irregularities and has an opening peripheral surface having a diameter larger than that of the female screw portion, and the inner lid bolt hole and the outer lid bolt hole in the trunk portion are formed. The radioactive substance storage method according to claim 10 or 11, wherein, in the step of attaching a lid bolt hole plug, the sealing material of the lid bolt hole plug is disposed on the peripheral surface of the opening.

Images