JP2013047652A - Radiation shield structure and construction method of radiation shield structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation shield structure capable of enhancing a radiation shield effect and efficiently charging a shield into a cylindrical body, and to provide a construction method for a radiation shield structure.SOLUTION: In a construction method of a radiation shield structure 10, a first partition body 28 is installed by being pressed into an outlet end 12B side from an inlet end 12A of a sleeve 12, while avoiding six existing pipes 14, 14... in a sleeve 12. Then, a lead wool shield 22 is stuffed on a front side of the first partition body 28 and a second partition body 30 is installed by being pressed into a front side of the lead wool shield 22. Then, solid shield materials 24, 24... are stuffed into a front side of the second partition body 30. After closing the inlet end 12A of the sleeve 12 by a cover 88, a liquid shielding agent 26 is injected into a gap between the cover 88 and the second partition body 30 and cured.

Description

  The present invention relates to a radiation shielding structure and a method for constructing a radiation shielding structure, and more particularly, to a radiation shielding structure and a radiation shielding structure provided in a through-hole of a nuclear power plant structure opened for penetrating piping. Regarding the method.

  The wall of the nuclear reactor containment vessel of the nuclear power plant is constructed of concrete having a thickness of about 2 m, and a plurality of pipes are provided through the through holes of the wall. In addition, the through hole is provided with a shielding material that shields radiation so that the radioactive substance in the reactor containment vessel does not leak outside through the through hole.

  In Patent Document 1, a sleeve is fitted into a through-hole in a wall, a lead hair shield is filled in a gap between the sleeve and the pipe, and thereafter, a flange-shaped steel plate is welded and fixed to the pipe or the like at both ends of the sleeve. A construction method for a radiation shielding structure is disclosed.

  Patent Document 1 discloses a mortar filling method in which a gap between a sleeve and a pipe passing through the sleeve is filled with mortar to shield radiation. The mortar filling method closes the gap between both ends of the sleeve and the outer peripheral surface of the pipe with a closed body, inserts the mortar pipe and the air vent pipe through one of the closed bodies, and removes the mortar from the mortar pipe. This is a method of filling the gap and discharging the air existing in the gap to the outside from the air vent pipe.

  On the other hand, in Patent Document 2, when a pipe installed in a nuclear reactor facility is repaired or replaced or removed, the pipe is filled with a fluid shielding material to shield radiation in the pipe. A method is disclosed. Patent Document 2 is not a shielding technique for shielding a through-hole in a wall as in Patent Document 1, but a shielding technique for simply filling a fluid shielding material in a pipe.

Japanese Patent Laid-Open No. 2002-181981 Japanese Patent Laid-Open No. 2001-4794

  Patent Document 1 discloses a radiation shielding structure filled with a lead hair shield suitable for gamma rays and a radiation shielding structure filled with concrete suitable for neutron radiation. A radiation shielding structure suitable for both gamma rays and neutron rays is not disclosed. Although a radiation shielding structure suitable for both of the above can be provided by using a mixed shielding body in which a lead hair shielding body and concrete are mixed, it is difficult to fill the mixed shielding body into the sleeve without a gap. It was.

  The present invention has been made in view of such circumstances, and in the radiation shielding technique in the cylinder in which the pipe is disposed, the radiation shielding structure that improves the radiation shielding effect and the shielding body are efficiently provided in the cylinder. It aims at providing the construction method of the radiation shielding structure which can be filled.

  In order to achieve the above object, the present invention provides a radiation shielding structure that shields a gap between a cylinder and a pipe inserted through the cylinder, and a lead hair shield is provided in the gap of the cylinder. A radiation shielding structure characterized in that a first shielding body and a second shielding body made of a solid shielding material and a hardened liquid shielding agent are filled through a partition member.

  According to the present invention, the lead hair shield mainly shielding gamma rays, the solid shielding material mainly shielding neutron rays, and the liquid shielding agent are mixed separately through the partition member without mixing them. A hair shield, a solid shielding material, and a liquid shielding agent can be reliably filled into the cylinder. This improves the radiation shielding effect.

  The partition member of the present invention is provided with a hole that is inserted into the cylindrical body and disposed on the outlet end side of the cylindrical body and through which the pipe is inserted, and an outer peripheral surface is fitted to an inner peripheral surface of the cylindrical body A first partition body that is inserted into the cylindrical body and disposed on the inlet end side of the cylindrical body and through which the pipe is inserted, and an outer peripheral surface is fitted on the inner peripheral surface of the cylindrical body. A second partition body to be combined, the gap between the first partition body and the second partition body is filled with the first shielding body, and the second partition body and the second partition body It is preferable that the gap between the cylindrical body and the inlet end is filled with the second shielding body. According to the present invention, the first shield and the second shield can be reliably partitioned and filled into the cylinder.

  The first partition body and the second partition body of the present invention are divided so as to sandwich the pipe from a direction orthogonal to the axial direction of the pipe, and a notch for allowing the pipe to escape. A first plate-like body provided with an elongated hole, and a notch-like elongated hole that is divided so as to sandwich the pipe from a direction orthogonal to the axial direction of the pipe and to release the pipe The second plate-like body provided, the first plate-like body and the second plate-like body are sandwiched, and the pipe is sandwiched from a direction orthogonal to the axial direction of the pipe. It is preferable to include a fitting body that is divided and includes a notch-like long hole for allowing the piping to escape, and is fitted to the inner wall surface of the cylindrical body with elasticity. According to the present invention, it is possible to easily attach the first partition and the second partition to the existing pipe disposed in the cylinder.

  According to the present invention, it is preferable that the first sandwiching body and the second sandwiching body sandwiching the first plate-like body and the second plate-like body sandwiching the fitting body are provided. . According to the present invention, the fitting body can be securely held between the first plate-like body and the second plate-like body.

  The cylindrical body according to the present invention is preferably a sleeve provided in a through hole provided in a wall of a reactor containment vessel.

  In order to achieve the above object, the present invention provides a radiation shielding structure construction method for shielding a gap between a cylinder and a pipe inserted through the cylinder, from the inlet side to the outlet side of the cylinder. A first step of inserting the first partition toward the first, a second step of packing the lead hair shield from the inlet side of the cylinder toward the first plate, and an inlet of the cylinder A third step of inserting a second partition from the side toward the lead hair shield, and a fourth step of packing a solid shielding material from the inlet side of the cylinder toward the second partition; , A fifth step of closing the inlet of the cylinder with a lid, and removing air from the cylinder from the air vent hole of the lid while injecting a liquid shielding agent into the cylinder from the inlet of the lid A sixth step of filling the cylindrical body with the liquid shielding agent, and curing of the liquid shielding agent Said lid provides a construction method for a radiation shielding structure characterized by having a seventh step of removing from said cylinder to.

  According to the present invention, it is possible to efficiently fill the cylindrical body with the first shielding body and the second shielding body.

  In the first step, the first partition is inserted into the cylindrical body through a first pressing member, and the first pressing member is the second step in the second step. It is preferable that it is fixed on the inlet side of the cylindrical body and removed from the first partition body and the cylindrical body after filling the lead hair shield. According to the present invention, it is possible to maintain the position of the first partition when filling the first shield. Further, according to the present invention, since the first pushing member is removed, the first pushing member does not get in the way when the second partition body is inserted in the third step.

  In the third step, the second partition is inserted into the cylindrical body via a second pushing member, and the second pushing member is inserted in the fourth step in the fourth step. It is preferable to be fixed on the inlet side of the cylinder. According to the present invention, the position of the second partition can be maintained when the solid shielding material and the liquid shielding agent are filled.

  In the fourth step of the present invention, it is preferable that a gap between the pipe insertion hole of the second partition and the pipe is sealed with a sealing material. According to the present invention, it is possible to prevent the liquid shielding agent from leaking from the gap of the second partitioning body into the filling area of the lead hair shielding body.

  According to the radiation shielding structure and the radiation shielding structure construction method of the present invention, the radiation shielding effect is improved and the shielding body can be efficiently filled into the cylinder.

Sectional drawing of radiation shielding structure of embodiment The perspective view of the 1st and 2nd partition Assembly perspective view of the first partition Assembly perspective view of second partition Sectional drawing of the sleeve by which the 1st partition and the lead hair shield were arranged Sectional drawing of the sleeve by which the 2nd partition and the solid shielding material were arrange | positioned Front view of the lid closing the inlet end of the sleeve Cross section of sleeve with air vent tube inserted Sectional view of sleeve with liquid shielding agent injection tube inserted Sectional view of sleeve after completion of liquid shielding agent injection

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a radiation shielding structure and a radiation shielding structure construction method according to the present invention will be described below with reference to the accompanying drawings.

The following embodiments to be described, the size 300A fitted in the through hole of the reactor containment vessel wall (the dimensions of the carbon steel pipe for piping: see JIS G 3452- _73), a length of about 2300mm sleeve ( A description will be given based on a structure in which six pipes having a size of 20A are provided through the cylinder. That is, the radiation shielding structure of the present invention is a shielding structure that is constructed in a gap between a sleeve and a pipe that is already installed in the sleeve. Further, the size of the sleeve is not limited to the above size, and the size and number of pipes are not limited to the above size and number. Furthermore, the shape of the sleeve may be a cylindrical body or a rectangular tube. Furthermore, the through hole is not limited to the through hole opened in the wall of the reactor containment vessel, and may be a through hole opened in the wall of the nuclear power plant structure that shields radiation.

  FIG. 1 is a sectional view of a completed product of the radiation shielding structure 10 according to the embodiment.

  The radiation shielding structure 10 shown in the figure is provided in a gap between a cylindrical sleeve 12 and six pipes 14, 14... Inserted through the sleeve 12 at a predetermined interval. The first shield 16 and the second shield 18 are filled with a plate-like partition member 20 and configured. The first shield 16 includes a lead hair shield 22 that mainly shields gamma rays, and the second shield includes a plurality of solid shields 24 that mainly shield neutron rays and a cured liquid shield 26. Become.

  In the embodiment, the left end of the sleeve 12 in the figure is defined as the inlet end 12A of the sleeve 12, and the right end of the sleeve 12 is defined as the outlet end 12B of the sleeve 12. Further, the sleeve 12 is installed in a through hole in the wall of the reactor containment vessel with a predetermined angle θ (0.5 ° or more) inclined in the upward direction with respect to the horizontal axis L. The reason why the sleeve 12 is installed in an inclined manner is to carry out the air venting operation when the liquid shielding agent 26 is injected. The liquid shielding agent 26 is a two-component mixture having a specific gravity of about 3.2 in which a main component having a lead component and a curing agent are mixed.

  The partition member 20 includes a first partition body 28 and a second partition body 30 configured in a disc shape.

  The first partition 28 is inserted from the inlet end 12 </ b> A of the sleeve 12 toward the outlet end 12 </ b> B and is disposed on the inlet end 12 </ b> A side from the center of the sleeve 12. Further, as shown in FIG. 2, six long holes 32, 32... Through which the six pipes 14, 14. These long holes 32, 32... Are closed by the semi-cured liquid shielding agent 33 when the first partition 28 is inserted to a predetermined position. Further, the outer peripheral surface of the first partition 28 is fitted to the inner peripheral surface of the sleeve 12, and the gaps present at the boundary portions thereof are sealed with the semi-cured liquid shielding agent 33.

  As shown in FIG. 1, the second partition 30 is inserted from the inlet end 12 </ b> A of the sleeve 12 toward the outlet end 12 </ b> B and is disposed on the inlet end 12 </ b> A side of the sleeve 12. Further, as shown in FIG. 2, the surface of the second partition 30 is provided with six long holes 32, 32, through which the six pipes 14, 14,. These long holes 32, 32... Are closed by a semi-cured liquid shielding agent (sealing material) 33 when the second partition 30 is inserted to a predetermined position. Further, the outer peripheral surface of the second partition body 30 is fitted to the inner peripheral surface of the sleeve 12, and the gap existing at the boundary portion thereof is sealed with the semi-cured liquid shielding agent 33. That is, the first partition 28 and the second partition 30 are the same structure.

  As shown in FIG. 1, the first shield 16 is filled in the gap between the first partition 28 and the second partition 30, and the second partition 30 and the inlet end 12 </ b> A of the sleeve 12 are The second shield 18 is filled in the gap between the two.

  Since the first partition 28 and the second partition 30 are the same structure as described above, here, the first partition 28 shown in FIG. 3 will be described, and the first partition 28 shown in FIG. About the 2 partition bodies 30, the code | symbol same as the 1st partition body 28 is attached | subjected, and the description is abbreviate | omitted.

  As shown in FIG. 3, the first partition 28 includes a first plate-like body 34, a second plate-like body 36, and a fitting body 38.

  The 1st plate-shaped body 34 is provided with the half-circle bodies 40 and 42 of the same shape divided into two which are faced | matched so that the existing six piping 14,14 ... may be clamped from an up-down direction. The semicircular bodies 40, 42 are provided with three notch-shaped long holes 44, 44... Formed in a direction perpendicular to the diameter of the semicircular bodies 40, 42. Therefore, each long hole is formed by abutting each side of the semicircular bodies 40, 42 in a direction perpendicular to the axial direction of the six pipes 14, 14 ... from above and below the six pipes 14, 14 ... 44, the two pipes 14 and 14 are inserted. Thereby, the first plate-like body 34 is attached to the existing six pipes 14, 14... Penetrating through the sleeve 12. Moreover, the 1st plate-shaped body 34 is manufactured with metals, such as SUS.

  The second plate-like body 36 has substantially the same shape as the first plate-like body 34. That is, the second plate-like body 36 is provided with two half-circle bodies 46 and 48 having the same shape divided into two so that the six pipes 14, 14. The semicircular bodies 46, 48 are provided with three notch-like long holes 50, 50... Formed in a direction perpendicular to the diameter of the semicircular bodies 46, 48. Therefore, each long hole is formed by abutting each side part of the semicircular bodies 46 and 48 in a direction orthogonal to the axial direction of the six pipes 14, 14... From the outside of the six pipes 14, 14. 50, two pipes 14 and 14 are inserted. As a result, the second plate-like body 34 is attached to the existing six pipes 14, 14... Penetrating the sleeve 12. The second plate-like body 36 is also made of a metal such as SUS.

  Furthermore, long holes 52 and 52 are provided at both ends of the side portions of the semicircular bodies 46 and 48 in a direction perpendicular to the side portions. The long holes 52 and 52 are long holes through which the pair of connecting rods 54 and 54 are inserted. One end portions of the connecting rods 54 are fixed to both end portions of the side portion when the diameter of the semicircular body 40 of the first plate-like body 34 is set as the side portion. Further, the connecting rods 54, 54 project in a direction perpendicular to the surface of the semicircular body 40.

  On the other hand, the connecting rods 54 and 54 of FIG. 4 are fixed to both end portions of the side portion when the diameter of the semicircular body 42 is set to the side portion. That is, the connecting rods 54 and 54 in FIG. 4 and the connecting rods 54 and 54 in FIG. 3 are arranged so as not to be buffered.

  The fitting body 38 has substantially the same structure as the first plate-like body 34 and the second plate-like body 36 except that the diameter of the fitting body 38 is the first plate-like body 34 and the second plate-like body. The outer peripheral surface of the fitting body 38 is fitted to the inner peripheral surface of the sleeve 12 with elasticity. Therefore, the fitting body 38 is made of a soft resin such as acrylic.

  The fitting body 38 includes two half-circle bodies 56, 58 having the same shape divided into two so as to face each other so as to sandwich the six pipes 14, 14. The semicircular bodies 56 and 58 are provided with three notch-like long holes 60 and 60 formed with the diameter of the semicircular bodies 56 and 58 as side portions and formed in a direction perpendicular to the side portions. Therefore, each long hole is made to face each other by abutting each side of the semicircular bodies 56, 58 in a direction perpendicular to the axial direction of the six pipes 14, 14 ... from the outside of the six pipes 14, 14 ... The two pipes 14, 14 are inserted through 60. As a result, the fitting body 38 is attached to the existing six pipes 14, 14... Penetrating the sleeve 12.

  Further, the semicircles 56 and 58 are provided with long holes 62 and 62 in a direction perpendicular to the side portion. The long holes 62 and 62 are long holes through which the pair of connecting rods 54 and 54 described above are inserted.

  The fitting body 38 configured in this manner is sandwiched between the first plate-like body 34 and the second plate-like body 36. The first partition body 28 includes a first sandwiching body 64 and a second sandwiching body 66 that sandwich the first plate-like body 34 and the second plate-like body 36 sandwiching the fitting body 38. It has.

  The first clamping body 64 and the second clamping body 66 are cross-shaped plate-like bodies, and arc-shaped concave portions 68, 68,... For avoiding the six pipes 14, 14,. It has been.

  That is, the first partition body 28 includes five plate-shaped members (first sandwiching body 64, first plate-like body 34, fitting body 38, second plate-like body 36, and second sandwiching body. 66). The five members 64, 34, 38, 36, 66 overlapped in this way are inserted into the through holes 70 of the members 66, 36, 38, 34 from the side of the second sandwiching body 66. .. Are integrated by fastening the bolts 72, 72... Into the screw holes 74 of the first clamping body 64.

  In addition, the 1st clamping body 64 and the 2nd clamping body 66 are not an essential structural member. However, by providing the first sandwiching body 64 and the second sandwiching body 66, the elongated hole on which the elongated holes 44, 50, and 60 are superimposed can be made as small as the elongated hole 32 in FIG. The long hole 32 is sealed with a semi-cured liquid shielding agent 33 after the first partition 28 and the second partition 30 are installed in the sleeve 12. Therefore, since the size of the overlapped elongated hole can be reduced as the elongated hole 32 by the first sandwiching body 64 and the second sandwiching body 66, the usage amount of the liquid shielding agent 33 can be reduced. . The long hole 32 has a long axis in the vertical direction, for the purpose of inserting the pipes 14, 14. 2 is a long hole on which the long holes 52 and 62 are superimposed, and the connecting rod 54 shown in FIGS. 3 and 4 protrudes from the long hole 76. The long hole 76 is also sealed with the liquid shielding agent 33.

  Next, the construction method of the radiation shielding structure 10 will be outlined.

  First, the first partition 28 is inserted from the inlet end 12A of the sleeve 14 to the outlet end 12B side as shown in FIG. 5 while avoiding the six existing pipes 14, 14. Next, the lead hair shield 22 is packed into the front side of the first partition 28 as shown in FIG. Next, as shown in FIG. 6, the second partition 30 is inserted in front of the lead hair shield 22. Then, the solid shielding materials 24, 24... Are packed on the front side of the second partition body 30. Then, the inlet end 12A of the sleeve 12 is closed by a lid (lid body) 88 in FIG. 7, and thereafter, the liquid shielding agent 26 in FIG. 10 is injected into the gap between the lid body and the second partition body 30. To cure. The radiation shielding structure 10 is applied in the sleeve 12 according to this procedure.

Therefore, problems and issues in implementing the construction method are as follows:
(A) To install the first partition body 28 and the second partition body 30 in FIG. 6 in the sleeve 12 while avoiding the existing six pipes 14, the first partition body 28 and the second partition body 28 What structure is the partition body 30 of?

  (B) After the first partition body 28 of FIG. 5 is installed at right angles to the sleeve 12 without a gap, when the lead hair shield 22 is pushed in and filled, the first partition body 28 tilts or the sleeve In order to prevent the rearward movement of the first partition body 28, the structure of the first partition 28 is held.

  (C) When injecting the liquid shielding agent 26 of FIG. 10, in order to prevent the liquid shielding agent 26 from leaking out to the lead hair shielding body 22 side from the second partitioning body 30, the second partitioning body 30. What structure is used to seal against the sleeve 12? There are problems and issues. The construction method of the embodiment described below solves such problems and problems.

  Next, the construction method of the radiation shielding structure 10 will be described in detail.

  (1) First, the first sandwiching body 64 and the second sandwiching body 66 are horizontally disposed with respect to the existing six pipes 14 and 14 shown in FIG. 3 disposed outside the inlet end 12A of the sleeve 12. The posture is passed through the gap between the pipes 14 and 14. Next, the postures of the first sandwiching body 64 and the second sandwiching body 66 are changed in the vertical direction, and the arc-shaped recesses 68, 68... Of the first sandwiching body 64 and the second sandwiching body 66 are respectively changed. Are brought close to the pipes 14, 14..., And the first holding body 64 and the second holding body 66 are held in this state. Thereby, the 1st clamping body 64 and the 2nd clamping body 66 are arrange | positioned avoiding piping 14, 14, ....

  (2) The upper half-circles 40, 46, and 56 of the first plate-like body 34, the second plate-like body 36, and the fitting body 38 of FIG. The sandwiching body 64 and the second sandwiching body 66 are inserted. At this time, the upper three pipes 14 are inserted into the long holes 44, 50, 60 of the semicircular bodies 40, 46, 56. Further, the two connecting rods 54, 54 fixed to the semicircular body 40 are disposed outside the semicircular body 46 through the long hole 62 of the semicircular body 56 and the long hole 52 of the semicircular body 46. Protruding.

  Next, three lower half circles 42, 48, and 58 of each of the first plate-like body 34, the second plate-like body 36, and the fitting body 38 of FIG. The sandwiched body 64 and the second sandwiched body 66 are inserted and held by hand. At this time, the lower three pipes 14 are inserted into the long holes 44, 50, 60 of the semicircular bodies 42, 48, 58.

  (3) A plurality of bolts 72, 72... Are inserted into the through holes 70 of the respective members 66, 36, 38, 34 from the side of the second sandwiching body 66 of FIG. Fastened to the screw hole 74. Thereby, the first partition 28 is attached to the six pipes 14, 14... Located outside the inlet end 12 </ b> A of the sleeve 12.

  (4) Next, as shown in FIGS. 3 and 4, a male cylinder 80 provided on one end of the push rod (first push member) 78, 78 is engraved on the other end of the connecting rod 54. The push rods 78, 78 are connected to the connecting rods 54, 54 by being screwed into a portion (not shown).

  (5) Using the two pushing rods 78, 78, the first partition 28 is pushed into the sleeve 12 from the inlet end 12A of the sleeve 12 as shown in FIG. 5 (first step). At this time, the fitting body 38 made of urethane has an outer diameter 2 mm larger than that of the first and second plate-like bodies 34 and 36 made of SUS, so that the fitting body 38 is made to have resistance to the inner peripheral surface of the sleeve 12. Push about 700mm against. As a result, the first partition 28 can be inserted and arranged at a predetermined position in the sleeve 12, so that the above-mentioned problem (a) and the problem can be solved. The connecting rods 54 and 54 are attached to both end portions of the side of the semicircular body 40 in order to facilitate the pushing operation of the first partition 28. On the other hand, if the connecting rod is attached to the center of the first partition 28, it is difficult to stably transmit the pushing force from the pushing rod to the first partition 28. Therefore, the first partition The pushing operation of the body 28 is difficult.

  (6) When the first partition 28 is inserted to a predetermined position as shown in FIG. 3, all the long holes 32 and 76 of the first partition 28 are closed by the semi-cured liquid shielding agent 33 as shown in FIG. . A semi-cured liquid shielding agent 33 is also applied to the boundary between the outer peripheral surface of the first partition 28 and the inner peripheral surface of the sleeve 12. Since the hole of the first partition 28 through which the pipe 14 is inserted is a long hole 32 having a long axis in the vertical direction, the pipe 14 can be connected even if the pipe 14 is inclined in the vertical direction relative to the sleeve 12. 14 and the long hole 32 can be inserted into the sleeve 12 without interference.

  (7) The other ends of the push rods 78, 78 are temporarily fixed to a bracket 82 attached to the end face of the inlet end 12A of the sleeve 12 as shown in FIG. The push rod 78 is provided with a turn buckle 84 for adjusting the length of the push rod 78. By adjusting the length of the push rod 78 by the turn buckle 84, the other ends of the push rods 78, 78 are arranged. It can be fitted to the bracket 82. The step (6) and the step (7) may be reversed.

  (8) After the liquid shielding agent 33 is cured, as shown in FIG. 5, about 30 kgf of lead hair shielding body 22 is packed into a space of about 200 mm in length (second step). The filling operation of the lead hair shield 22 is performed by the operator pushing the lead hair shield 22 with the rod while avoiding the six pipes 14, 14... And the pair of push rods 78, 78. At this time, since the first partition 28 is fixed to the inlet end 12A side of the sleeve 12 via the two push rods 78, 78, when the lead hair shield 22 is pushed in and filled, the first partition 28 is fixed. It is possible to prevent the one partition body 28 from tilting or moving to the back side. Therefore, the above-mentioned problem (b) and the problem can be solved.

  (9) After filling the lead hair shield 22, the fixed ends of the push rods 78, 78 are removed from the bracket 82, and then the push rods 78, 78 are rotated in a loosening direction so that the screw cylinders of the push rods 78, 78 are removed. 80 is removed from the connecting rod 54. Then, the push rods 78 and 78 are extracted from the sleeve 12. Thereby, since the push rods 78 and 78 do not exist at the time of insertion of the 2nd partition body 30 mentioned later, the 2nd partition body 30 can be inserted and arrange | positioned in the sleeve 12 without a problem.

  (10) As shown in FIG. 6, the second partition 30 is pushed and inserted into the rear stage of the lead hair shield 22 in the same manner as the first partition 28 (third step). However, as shown in FIG. 4, the push rods 78 and 78 are connected at one end to a connecting rod 54 attached to the lower half semicircle 42 of the half crack through a screw cylinder 80. Further, the other ends of the push rods 78 and 78 are temporarily fixed to a bracket 86 attached to the end face of the inlet end 12A of the sleeve 12 as shown in FIG. Thereafter, all the long holes 32 and 76 of the second partition 30 are closed with the semi-cured liquid shielding agent 33 as shown in FIG. A semi-cured liquid shielding agent 33 is also applied to the boundary between the outer peripheral surface of the second partition 30 and the inner peripheral surface of the sleeve 12. Thereby, at the time of injection | pouring of the liquid shielding agent 26 mentioned later, it can prevent that the liquid shielding agent 26 leaks out from the 2nd partition 30 to the lead hair shielding body 22 side. Therefore, the above-mentioned problems (c) and problems can be solved.

  (11) As shown in FIG. 6, a plurality of solid shielding materials 24, 24... Are packed in the gap between the inlet end 12A of the sleeve 12 and the second partition 30 (fourth step). In FIG. 6, only one solid shielding material 24 is shown, but this solid shielding material 24 is packed in the entire gap.

  (12) A transparent acrylic lid 88 is attached to the inlet end 12A of the sleeve 12 as shown in FIG. 7 to close the inlet end 12A (fifth step). The lid 88 is composed of divided pieces 88A, 88B, 88C, 88D that are divided into four parts in order to avoid the six pipes 14, 14,. When the sleeve 12 is fixed to the inlet end 12A, the ends of the adjacent divided pieces 88A to 88D are bonded together to form the lid 88.

  (13) As shown in FIG. 8, the air vent tube 92 is inserted into the gap between the lid 88 and the second partition body 30 through the through hole 90 provided in the upper portion of the lid 88, and the leading end of the air vent tube 92 is opened. The part 93 is brought close to the second partition body 30. Since the sleeve 12 is inclined in the upward direction, when the liquid shielding agent 26 is injected, the position of the tip opening 93 becomes an air reservoir. Therefore, by bringing the tip opening 93 of the air vent pipe 92 close to the second partition body 30, the air in the gap can be surely extracted.

  The gaps between the six pipes 14 and the lid 88 are also sealed with a semi-cured liquid shielding agent (not shown). Thereafter, as shown in FIG. 9, an injection tube 96 for injecting the liquid shielding agent 26 is inserted into the gap from the through hole 94 of the lid 88, and the liquid shielding agent 26 is injected from the injection tube 96 as shown in FIG. That is, the liquid shielding agent 26 is sent out to the injection pipe 96 by a transfer pump (not shown) and injected into the gap. The liquid shielding agent 26 is filled so as to gradually rise from the lower left side of the gap to the right side. At that time, air existing in the gap is discharged from the air vent pipe 92 to the outside. Then, when the liquid shielding agent 26 overflows from the air vent pipe 92, the transfer pump is stopped and the injection of the liquid shielding agent 26 is stopped (sixth step). Thereby, the liquid shielding agent 26 is filled in the entire area of the gap. Since the second partition 30 is fixed to the inlet end 12A of the sleeve 12 via the two push rods 78, 78 when the liquid shielding agent 26 is injected, the second partition 30 falls or moves toward the lead hair shield 22 side. There is nothing to do.

  Thereafter, when the liquid shielding agent 26 is semi-cured, the air vent tube 92 and the injection tube 96 are extracted from the liquid shielding agent 26. And the hole formed in the liquid shielding agent 26 by extracting the air vent pipe 92 and the injection pipe 96 is filled with the semi-cured liquid shielding agent 26. In order to prevent the liquid shielding agent 26 from adhering to the contact surfaces of the air vent tube 92 and the injection tube 96 with the liquid shielding agent 26, it is preferable to apply a release agent in advance.

  (14) After the liquid shielding agent 26 is completely cured, the lid 88 is removed from the inlet end 12A of the sleeve 12 for each of the divided pieces 88A to 88D (seventh step).

  (15) Thereafter, the half-split iron collars 98, 98, 98 shown in FIG. 1 are mounted on the sleeve 12 on the inlet end 12A side in a triple manner to increase the shielding effect of the inlet end 12A.

  The radiation shielding structure 10 according to the embodiment can be applied to the sleeve 12 by the above installation procedure.

  According to the radiation shielding structure 10 of the embodiment, as shown in FIG. 1, the lead hair shield 22 that shields gamma rays, the solid shielding material 24 that shields neutron rays, and the liquid shielding agent 26 are mixed without mixing. Since each is filled separately via the member 20, the lead hair shield 22, the solid shielding material 24 and the liquid shielding agent 26 can be reliably filled into the sleeve 12. This improves the radiation shielding effect.

On the other hand, when the first shield 16 and the second shield 18 have the same volume, the gamma ray shielding effect (when radiation enters from the inlet end 12A of the sleeve 12) is as follows:
First shield 16: second shield 18≈30 (%): 70 (%),
The shielding effect of neutron rays is
First shield 16: second shield 18≈15 (%): 85 (%).

The shielding effect of gamma rays when the volume ratio of the first shield 16 and the second shield 18 is 1: 2 is as follows:
First shield 16: second shield 18≈35 (%): 65 (%),
The shielding effect of neutron rays is
First shield 16: second shield 18≈43 (%): 57 (%).

  That is, by changing the volume ratio of the first shield 16 and the second shield 18, it is possible to cope with applications where it is desired to shield more gamma rays than neutron rays and to shield more neutron rays than gamma rays. . This is an effect obtained by partitioning and filling the first shield 16 and the second shield 18.

[Appendix]
As the liquid shielding agent 26 of the embodiment, a liquid shielding agent having a higher shielding rate of neutron rays than that of concrete of the same capacity [Product name: RADLESKRAFTON (registered trademark), research and development source: Neotec RIKEN, Ltd., manufacturer : Fujix Co., Ltd.].

  The liquid shielding agent may be one or more two-component mixed curing resins selected from the group consisting of phenol resin, epoxy resin, cresol resin, xylene resin, urea resin, and unsaturated polyester resin, and Pb, W, Cr, Co. , Cu, Fe, Mn, Mo, Ag, Ta, Cd, Dy, Eu, Gd, Au, In, Hg, Re, Sn and U. It mixes so that a molded object density may become 2.0 or more. According to this radiation shielding agent, simultaneous shielding of gamma rays, X-rays and neutron rays is possible.

  As the radiation shielding agent, it is desirable to use a thermosetting resin that is resistant to heat. For example, a phenol resin, an epoxy resin, a cresol resin, a xylene resin, a urea resin, an unsaturated polyester resin, or the like is used singly or in combination. . The thermosetting resin has sufficient strength, excellent moldability, and workability, and has relatively high heat resistance. Depending on the selection, it can be used at 150 ° C. or higher.

  DESCRIPTION OF SYMBOLS 10 ... Radiation shielding structure, 12 ... Sleeve, 12A ... Inlet end, 12B ... Outlet end, 14 ... Piping, 16 ... 1st shielding body, 18 ... 2nd shielding body, 20 ... Partition member, 22 ... Lead hair Shielding body, 24 ... solid shielding material, 26 ... liquid shielding agent, 28 ... first partitioning body, 30 ... second partitioning body, 32 ... long hole, 33 ... liquid shielding agent, 34 ... first plate-like body , 36 ... second plate-like body, 38 ... fitting body, 40, 42 ... semicircle, 44 ... long hole, 46, 48 ... semicircle, 50 ... long hole, 52 ... long hole, 54 ... connecting rod 56, 58 ... semicircular, 60 ... long hole, 62 ... long hole, 64 ... first sandwiching body, 66 ... second sandwiching body, 68 ... arc-shaped recess, 70 ... through hole, 72 ... bolt, 74 ... Screw hole, 76 ... Long hole, 78 ... Push rod, 80 ... Screw cylinder, 82 ... Bracket, 84 ... Turnbuckle, 86 ... Bracket, 88 ... Lid, 8A, 88B, 88C, 88D ... the split piece, 90 ... through hole, 92 ... air vent tube, 94 ... through hole, 96 ... injection pipe, 98 ... color

Claims (9)

In the radiation shielding structure that shields the gap between the cylinder and the pipe inserted through the cylinder,
The gap between the cylinders is filled with a first shielding body made of a lead hair shielding body and a second shielding body made of a solid shielding material and a hardened liquid shielding agent via a partition member. Characteristic radiation shielding structure. The partition member is
A first partition that is inserted into the cylinder and disposed on the outlet end side of the cylinder and includes a hole through which the pipe is inserted, and an outer peripheral surface is fitted to an inner peripheral surface of the cylinder; ,
A second partition that is inserted into the cylinder and disposed on the inlet end side of the cylinder and includes a hole through which the pipe is inserted, and an outer peripheral surface is fitted to an inner peripheral surface of the cylinder; With
The gap between the first partition and the second partition is filled with the first shield, and the gap between the second partition and the inlet end of the cylindrical body is filled with the first shield. The radiation shielding structure according to claim 1, which is filled with two shielding bodies. The first partition and the second partition are:
A first plate-like body which is divided so as to sandwich the pipe from a direction orthogonal to the axial direction of the pipe and which has a notch-like elongated hole for allowing the pipe to escape;
A second plate-like body that is divided so as to sandwich the pipe from a direction orthogonal to the axial direction of the pipe and is provided with a notch-shaped long hole for allowing the pipe to escape;
A clip that is sandwiched between the first plate and the second plate to divide the pipe from a direction perpendicular to the axial direction of the pipe and to release the pipe. A fitting body provided with a notch-shaped elongated hole and fitted with elasticity to the inner wall surface of the cylindrical body;
The radiation shielding structure according to claim 2, comprising:   The radiation shielding structure according to claim 3, further comprising: a first sandwiching body and a second sandwiching body sandwiching the first plate-like body and the second plate-like body sandwiching the fitting body. body.   The radiation shielding structure according to any one of claims 1 to 4, wherein the cylindrical body is a sleeve provided in a through hole provided in a wall of a reactor containment vessel. In the construction method of the radiation shielding structure that shields the gap between the cylinder and the pipe inserted through the cylinder,
A first step of inserting a first partition from the inlet side to the outlet side of the cylindrical body;
A second step of packing the lead hair shield from the inlet side of the cylindrical body toward the first plate-like body;
A third step of inserting a second partition from the inlet side of the cylindrical body toward the lead hair shield;
A fourth step of packing a solid shielding material from the inlet side of the cylindrical body toward the second partition;
A fifth step of closing the inlet of the cylindrical body with a lid;
A sixth step of filling the cylinder with the liquid shielding agent by injecting the liquid shielding agent from the inlet of the lid into the cylinder while extracting air from the air vent hole of the lid; ,
A seventh step of removing the lid from the cylinder after the liquid shielding agent is cured;
The construction method of the radiation shielding structure characterized by having. In the first step, the first partition is inserted into the cylindrical body via a first pushing member,
The said 1st pushing member is removed from the said 1st partition body and the said cylinder after the filling of the said lead hair shielding body while being fixed by the entrance side of the said cylinder in the said 2nd process. The construction method of the radiation shielding structure of 6. In the third step, the second partition is inserted into the cylindrical body through a second pushing member,
The construction method for the radiation shielding structure according to claim 6 or 7, wherein the second pushing member is fixed on the inlet side of the cylindrical body in the fourth step.   The construction of the radiation shielding structure according to any one of claims 6 to 8, wherein, in the fourth step, a gap between a pipe insertion hole of the second partition and the pipe is sealed with a sealing material. Method.

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