Geological disposal facility and geological disposal method

Abstract

To provide a geological disposal facility and a geological disposal method capable of efficiently transporting a waste body package.SOLUTION: A geological disposal facility 1 for disposing radioactive waste in a geological disposal system comprises: a disposal tunnel 21 in which a cylindrical waste body package 11 containing radioactive waste is disposed in a horizontal orientation; and a pack guiding unit 72 installed in the disposal tunnel 21 for guiding the waste body package 11 moving independently within the disposal tunnel 21 to a fixed position 11p. The pack guide unit 72 includes: a main body part 77 placed on the internal surface of the disposal tunnel 21; and a plurality of balls 71 provided on the main body part 77 and rolling on a cylindrical side surface 11a of the waste body package 11.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a geological disposal facility and a geological disposal method. [Background technology]

[0002] A known technology in this field is the geological disposal facility described in Patent Document 1 below. In this geological disposal facility, waste transported by sea is placed in a storage container at a port facility and processed as a waste package. The waste package is transported from the surface facility to the underground facility by a pneumatic conveying system, and then transported to the disposal tunnel via the main tunnel. After arriving at the disposal tunnel, the waste package is received by a dedicated transport vehicle or device and directed toward the entrance of the disposal tunnel using a turntable. Finally, the waste package is pushed into the disposal tunnel and placed in a predetermined position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-286451 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned geological disposal facility, the waste package does not always move smoothly toward the back of the disposal tunnel after being pushed into the disposal tunnel. Therefore, the transport efficiency of the waste package 11 within the facility is not necessarily good. An object of the present invention is to provide a geological disposal facility and a geological disposal method that enable the efficient transport of waste packages. [Means for solving the problem]

[0005] The gist of the present invention lies in the following [1] to [4].

[0006] [1] A geological disposal facility for the geological disposal of radioactive waste, comprising: a disposal tunnel in which a cylindrical waste package containing the radioactive waste is placed and disposed of in a horizontal manner; and a pack guide unit that is installed within the disposal tunnel and guides the waste package, which moves independently within the disposal tunnel, to a placement position, wherein the pack guide unit has a main body that is placed on the inner wall surface of the disposal tunnel, and a plurality of rolling elements that are provided in the main body and roll on the cylindrical side surface of the waste package.

[0007] [2] The geological disposal facility according to claim 1, wherein the pack guide unit further comprises a plurality of other rolling elements provided in the main body and rolling on the inner wall surface of the disposal tunnel.

[0008] [3] A geological disposal facility as described in [1] or [2], wherein the disposal tunnel has a bottom wall surface and side wall surfaces rising from both ends of the bottom wall surface, and the pack guide units are installed along two corners of the bottom wall surface and the side wall surface.

[0009] [4] A geological disposal method for geologically disposing of radioactive waste in a geological disposal facility described in any one of [1] to [3], comprising a unit retrieval step in which a predetermined number of waste packages are placed in the disposal tunnel by guidance using the pack guiding unit, and then the pack guiding unit is withdrawn in the longitudinal direction of the disposal tunnel to retrieve them. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a geological disposal facility and a geological disposal method that are capable of efficiently transporting waste packages. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a geological disposal facility for radioactive waste. [Figure 2] FIG. 1 is a cross-sectional perspective view of a waste package. [Figure 3]FIG. 1(a) is a diagram showing an example of a disposal section with a dead-end layout, and FIG. 1(b) is a diagram showing an example of a disposal section with a panel layout. [Figure 4] 1(a) is a cross-sectional view showing a vertically placed stationary system, and FIG. 1(b) is a cross-sectional view showing a horizontally placed stationary system. [Figure 5] FIG. 2 is a cross-sectional view showing a schematic diagram of the transport route of the waste package from the ground facility to the emplacement position. [Figure 6] (a) is an enlarged horizontal cross-sectional view of the vicinity of the junction between the access tunnel and the disposal tunnel, and (b) is a vertical cross-sectional view of the junction. [Figure 7] FIG. 1(a) is a side view showing the first transporting carriage, and FIG. 1(b) is a perspective view showing the sealing plate of the first transporting carriage. [Figure 8] 1(a) is a cross-sectional view showing the state of the vicinity of the connection part during the transportation of the waste package, and FIG. 1(b) is a cross-sectional view showing the state of the disposal tunnel during the transportation of the waste package. [Figure 9] (a) is a cross-sectional view of the disposal tunnel. [Figure 10] FIG. 2(a) is a perspective view of the pack guide unit, and FIG. 2(b) is a cross-sectional view of the pack guide unit. [Figure 11] 10A and 10B are cross-sectional views showing a unit collecting step for collecting the pack guide unit. [Figure 12] FIG. 10 is a cross-sectional view showing a modified example of the pack guiding unit. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a geological disposal facility and a geological disposal method according to the present invention will be described in detail with reference to the drawings.

[0013] As shown in FIG. 1 , the geological disposal facility 1 for radioactive waste in this embodiment comprises an underground disposal compartment 3 where radioactive waste is disposed of, and an aboveground facility 5. The disposal compartment 3 is located at a depth of 300 m or more underground. The geological disposal facility 1 further comprises access tunnels 7a and 7b and a connecting tunnel 9 as tunnels connecting the aboveground facility 5 and the disposal compartment 3. The access tunnel 7a is a vertical shaft extending vertically downward from the aboveground facility 5, and the access tunnel 7b is an inclined shaft extending spirally downward from the aboveground facility 5. Note that the access tunnel 7b may also be a linear inclined shaft. The lower ends of the access tunnels 7a and 7b are connected to the connecting tunnel 9, and the disposal compartment 3 extends to the side of the connecting tunnel 9. The disposal compartment 3 extends over an area of, for example, approximately 500 m x 1,000 m.

[0014] FIG. 2 shows an example of a waste package 11 to be disposed of in the disposal area 3. The waste package 11 is a module containing radioactive waste to be disposed of and is also called a PEM (Pre-Fabricated Engineered Barrier System Module). The waste package 11 is cylindrical, for example, with a diameter of approximately 2 to 3 m and an axial length of approximately 3 to 4 m, and weighs, for example, approximately 30 tons. The waste package 11 includes a waste package 12, a buffer material 13 made primarily of bentonite that surrounds the waste package 12, and a steel storage container 14 that further covers the buffer material 13. The waste package 12 includes a cylindrical stainless steel canister 12a and a cylindrical thick-walled steel overpack 12b in which the canister 12a is hermetically contained. The canister 12a contains vitrified high-level radioactive waste to be disposed of. The waste package 11 is fabricated in the above-ground facility 5.

[0015] The layout of the disposal compartment 3 can be of two types: a "dead-end" type and a "panel" type. Either layout may be adopted for the geological disposal facility 1. As shown in an example in Figure 3(a), a disposal compartment 3 with a dead-end layout has multiple disposal tunnels 21 branching off from an access tunnel 9. Waste packages 11 are placed in the disposal tunnels 21 for disposal. One end of the disposal tunnel 21 is connected to the access tunnel 9, and the other end of the disposal tunnel 21 is a dead end. As shown in an example in Figure 3(b), a disposal compartment 3 with a panel layout has multiple disposal tunnels 21 similar to those described above, and main tunnels 23 that are arranged around the multiple disposal tunnels 21 and connected to the access tunnel 9. One end of each disposal tunnel 21 is connected to the access tunnel 9, and the other end is connected to the main tunnel 23. In general, the "main tunnel" may be included in the "access tunnel" category.

[0016] There are two possible emplacement methods for waste packages 11 in the disposal tunnel 21: a "vertical placement method" and a "horizontal placement method." Either emplacement method may be adopted in the geological disposal facility 1. As shown in an example in Figure 4(a), in the vertical placement method, a number of disposal holes 31 are drilled at predetermined intervals in the bottom of the disposal tunnel 21, and one waste package 11 is placed in each disposal hole 31. The waste package 11 to be disposed of is moved within the disposal tunnel 21 by a predetermined transportation means to the position of a predetermined disposal hole 31 and placed in that disposal hole 31. The space above the waste package 11 is then backfilled with backfill material 33 or the like to close the disposal hole 31, thereby completing the disposal.

[0017] As shown in an example in Figure 4(b), in the horizontal placement method, a large number of waste packages 11 are placed in a row coaxially along the cylindrical axis with their cylindrical axes facing the longitudinal direction of the disposal tunnel 21. A spacer 10 of the same diameter as the waste package 11 is sandwiched between adjacent waste packages 11. The waste package 11 to be disposed of is inserted from the access tunnel 9 into the disposal tunnel 21 in the above-mentioned orientation, and moved within the disposal tunnel 21 by a predetermined moving means. The waste package 11 is then placed at the emplacement position where it hits a spacer 10 previously installed within the disposal tunnel 21, thereby completing the disposal. Note that the spacer 10 may be omitted, in which case the waste packages 11 are placed in the disposal tunnel 21 so that their end faces are directly butted against each other. In this emplacement method, the waste package 11 inserted into the disposal tunnel 21 from the access tunnel 9 is moved within the disposal tunnel 21 by a predetermined moving means, and is placed at the position where it hits another waste package 11 that has already been placed, thereby completing the disposal.

[0018] In this embodiment, the layout of the disposal section 3 is a dead-end type layout, and the emplacement method of the waste package 11 is a horizontal placement method.

[0019] Next, we will explain the transportation system 40 that transports the waste package 11 produced in the ground facility 5 to the emplacement position. Figure 5 is a cross-sectional view that schematically shows the transportation route of the waste package 11 from the ground facility 5 to the emplacement position. In the following explanation, when we simply say "upstream / downstream", we mean upstream / downstream of the transportation of the waste package 11 by the transportation system 40.

[0020] As shown in Figure 5, the transportation system 40 includes a transport unit 41 that transports the waste package 11 within the access tunnel 7a, a transport unit 42 that transports the waste package 11 within the connecting tunnel 9 (transport tunnel), and a transport unit 43 that transports the waste package 11 within the disposal tunnel 21. The transport unit 41 is configured, for example, with a known pneumatic transport device. For example, the transport unit 41 includes the access tunnel 7a that functions as a pneumatic transport pipeline, and a pneumatic transport capsule 45 that carries the waste package 11 and moves up and down within the access tunnel 7a by pneumatic transport. The transport unit 42 includes the connecting tunnel 9 that functions as a pneumatic transport pipeline, and a first transport vehicle 47 that moves within the connecting tunnel 9 by pneumatic transport.

[0021] The transport section 43 is equipped with a disposal tunnel 21 that moves the waste package 11 individually to the emplacement position. The disposal tunnel 21 has a downward slope that descends from the connection section 55 with the access tunnel 9 toward the tip. This downward slope allows the waste package 11 to move within the disposal tunnel 21 under its own weight. The transport section 43 also has a pack guide section 70 that guides the waste package 11 moving as described above to the emplacement position. The pack guide section 70 will be described in detail later.

[0022] Although blowers for generating airflows for air transport are provided at appropriate locations in the transportation system 40, illustrations and descriptions of these blowers are omitted as appropriate. One such blower, blower 51, is provided, for example, at the most upstream portion of the connecting tunnel 9. The blower 51 controls the airflow in the connecting tunnel 9 by remote control from, for example, the surface facility 5, and controls the movement of the first transport vehicle 47 in the connecting tunnel 9 and the movement of the second transport vehicle 49 in the disposal tunnel 21 through this airflow control. For example, by blowing air from the most upstream portion of the connecting tunnel 9, the blower 51 can impart downstream propulsive force to the first transport vehicle 47 and the second transport vehicle 49, causing them to travel downstream. Furthermore, by drawing air from the most upstream portion of the connecting tunnel 9, the blower 51 can impart upstream propulsive force to the first transport vehicle 47 and the second transport vehicle 49, causing them to travel upstream. Such air transport methods are well known, and therefore further detailed description will be omitted.

[0023] The configuration of the above-mentioned transport sections 42, 43 will be further explained. Figure 6(a) is a horizontal cross-sectional view showing the vicinity of the connection 55 between the access tunnel 9 and the disposal tunnel 21, and Figure 6(b) is a vertical cross-sectional view of the connection 55. As shown in the figure, the access tunnel 9 comprises a main tunnel 9a and a plurality of branch tunnels 9b formed so as to deviate laterally from the main tunnel 9a. The branch tunnels 9b are access roads for entering each disposal tunnel 21 from the main tunnel 9a, and the same number of branch tunnels 9b as the number of disposal tunnels 21 are provided at equal intervals. The downstream end of each branch tunnel 9b is connected to the upstream end of the disposal tunnel 21. The main tunnel 9a and the branch tunnels 9b each have a rectangular cross-section, for example, with a height of about 5m.

[0024] The disposal tunnel 21 is slightly narrower than the connecting tunnel 9, and is connected to a branch tunnel 9b. The disposal tunnel 21 has a horseshoe-shaped cross section, for example, with a height of about 3 m. Due to the difference in shape and size between the branch tunnel 9b of the connecting tunnel 9 and the disposal tunnel 21, a step 56 is formed at the connection 55. At the connection 55, the branch tunnel 9b and the disposal tunnel 21 are connected so that the extension directions of the branch tunnel 9b and the disposal tunnel 21 at the connection 55 are the same.

[0025] Additionally, a movable air gate 53 is installed within the main road 9a to control the air transport of the first transport vehicle 47. The air gate 53 is arranged so as to substantially block the cross section of the main road 9a and is movable in the upstream and downstream directions within the main road 9a. For example, if the air gate 53 is positioned within the main road 9a slightly downstream of a predetermined branch road 9b, the first transport vehicle 47 traveling along the main road 9a from upstream will be guided to deviate into that branch road 9b. In this manner, the position of the air gate 53 can determine which branch road 9b and disposal tunnel 21 the first transport vehicle 47 will be directed to. The air gate 53 may be movable within the main road 9a by airflow control using a blower 51. Alternatively, the air gate 53 may be movable within the main road 9a by a predetermined drive mechanism.

[0026] The first transport vehicle 47 shown in FIG. 7(a) can carry a waste package 11 in a separable state. The first transport vehicle 47 includes a main body 47a, wheels 47c attached to the bottom of the main body 47a, and a sealing plate 47f attached to the upstream end of the main body 47a. The upper surface of the main body 47a functions as a loading platform 47h for carrying the waste package 11. The waste package 11 is loaded onto the loading platform 47h with its cylindrical axis oriented in the longitudinal direction of the access tunnel 9. The loading platform 47h has a number of unpowered rollers 47j arranged in the upstream and downstream directions, each with a rotation axis extending in the width direction of the vehicle. The waste package 11 is placed on these rollers 47j. The wheels 47c roll on the bottom wall of the access tunnel 9 when the first transport vehicle 47 moves by pneumatic conveyance.

[0027] The waste package 11 can slide in the cylindrical axial direction on the loading platform 47h, but movement of the waste package 11 in the cylindrical axial direction is restricted by the pack holding parts 47e that hold the waste package 11 by sandwiching it from both sides in the vehicle width direction. Specifically, the pack holding part 47e extends downstream from the sealing plate 47f, and a claw part 47k that hooks onto the downstream end face of the waste package 11 is provided on the downstream end side of the pack holding part 47e. The waste package 11 is sandwiched between the claw part 47k and the sealing plate 47f in the cylindrical axial direction, thereby restricting movement of the waste package 11 in the cylindrical axial direction. The state in which the waste package 11 is held by the claw part 47k of the pack holding part 47e can be released by remote control from the ground facility 5, for example. The released waste package 11 can slide out of the loading platform 47h and move downstream while being guided by the rollers 47j.

[0028] As shown in FIG. 7(b), the sealing plate 47f has a rectangular shape slightly smaller than the cross section of the connecting tunnel 9. The sealing plate 47f also has a through-hole 47d that penetrates in the upstream-downstream direction. The through-hole 47d is positioned corresponding to the waste package 11 on the loading platform 47h and has a smaller diameter than the waste package 11. The waste package 11 is placed on the loading platform 47h with its upstream end face generally abutting the sealing plate 47f, so that the through-hole 47d is blocked by the upstream end face of the loaded waste package 11. With the through-hole 47d blocked in this manner, the sealing plate 47f receives the airflow from the blower 51 and generates a propulsive force for the first transport vehicle 47. This propulsive force allows the first transport vehicle 47 to travel within the connecting tunnel 9.

[0029] A transportation method using the transportation system 40 as described above will be described. The waste package 11 produced in the ground facility 5 is transported downward through the access tunnel 7a by the transport unit 41 (Fig. 5). At the relay point 8, which is the connection between the access tunnel 7a and the connecting tunnel 9, the waste package 11 is transferred from the transport unit 41 to the transport unit 42. Specifically, as shown in Fig. 7, the waste package 11 is transferred from the pneumatic transport capsule 45 to the first transport vehicle 47. That is, the waste package 11 is loaded onto the loading platform 47h of the first transport vehicle 47 and fixed in the cylindrical axial direction by the pack holder 47e.

[0030] Then, as shown in FIG. 6(a), in the connecting tunnel 9, the first transport vehicle 47 travels downstream along the main road 9a under the airflow control of the blower 51 and enters a predetermined branch road 9b defined by the air gate 53. Then, as shown in FIG. 8(a), the first transport vehicle 47 hits the step 56 (stopper) of the connecting section 55 and stops. In this state, the airflow control by the blower 51 continues, and the first transport vehicle 47 is pressed against the step 56 by the airflow. Then, the waste package 11 is released from the pack holder 47e by remote control from, for example, the ground facility 5. Then, the waste package 11 receives the airflow through the through-hole 47d, and is pushed downstream from the loading platform 47h and transferred to the disposal tunnel 21. Here, the waste package 11 smoothly slides downstream from the loading platform 47h due to the rolling of the rollers 47j. Furthermore, since the waste package 11 on the loading platform 47h is arranged to fit within the outline of the disposal tunnel 21 when viewed from the axial direction (upstream / downstream direction), the waste package 11 is smoothly transferred from the loading platform 47h to the disposal tunnel 21. Meanwhile, the first transport vehicle 47, from which the waste package 11 has been separated, is returned to the relay location 8 by airflow control using the blower 51. At this time, a lid may be provided to cover the through-hole 47d so that the first transport vehicle 47 can fully receive the airflow from the blower 51.

[0031] As shown in Figure 8(b), the waste package 11 that has been transferred to the disposal tunnel 21 moves independently under its own weight through the downwardly sloping disposal tunnel 21 with its cylindrical axis oriented in the longitudinal direction of the disposal tunnel 21 until it hits the spacer 10 that has been installed earlier and stops. The position where the waste package hits the spacer 10 is designated as the emplacement position 11p, and the waste package 11 is placed horizontally, thereby completing the disposal of the waste package 11. Note that as the waste package 11 moves through the disposal tunnel 21, the air ahead of the waste package 11 in the direction of movement is compressed, and the compressed air gradually flows out behind the waste package 11 through the gap between the waste package 11 and the disposal tunnel 21. This phenomenon reduces the movement speed of the waste package 11 and reduces the impact when it collides with the spacer 10.

[0032] In order to smoothly guide the waste package 11 moving within the disposal tunnel 21 to the emplacement position 11p as described above, pack guides 70 are provided at two locations on the bottom of the disposal tunnel 21, as shown in Figure 9. The pack guides 70 are installed in the gap between the path of the waste package 11 in the disposal tunnel 21 and the inner wall surface of the disposal tunnel 21. The waste package 11 inserted into the disposal tunnel 21 from the access tunnel 9 by the first transport vehicle 47 is supported by the two pack guides 70, 70 located at both corners of the bottom. The pack guides 70 extend over the entire length of the disposal tunnel 21.

[0033] Each pack guide section 70 is composed of a plurality of pack guide units 72 arranged without gaps in the longitudinal direction of the disposal tunnel 21. The pack guide units 72 are connected in series in a string-like manner by cables 78 (see Figure 11) or the like. The disposal tunnel 21 has a horseshoe-shaped cross section and includes a bottom wall surface 21b and side wall surfaces 21c that rise approximately vertically from both ends of the bottom wall surface 21b. The pack guide section 70 is arranged along the corner between the bottom wall surface 21b and the side wall surface 21c, and has a triangular prism shape with a roughly right-angled triangular cross section. One face of the triangular prism is located along the bottom wall surface 21b, and the other face is located along the side wall surface 21c.

[0034] As shown in Figures 10(a) and 10(b), the pack guide unit 72 includes a triangular prism-shaped main body 77 disposed on the bottom wall surface 21b of the disposal tunnel 21. A sloped surface 77a of the main body 77 facing the waste package 11 is provided with a plurality of balls 71 (rolling elements) that roll on the cylindrical side surface 11a of the waste package 11. The balls 71 are arranged in two rows on the sloped surface 77a along a straight line extending in the longitudinal direction of the main body 77. More specifically, a number of ball transfer units 73 are embedded in the sloped surface 77a of the main body 77. Each ball transfer unit 73 includes a housing 75 embedded in the sloped surface 77a and the balls 71 that are rotatably held in the housing 75 and protrude slightly beyond the sloped surface 77a. Such ball transfer units 73 are installed along the entire longitudinal direction of the main body 77.

[0035] Similarly to the above, ball transfer units 83 are embedded in the bottom surface 77b of the main body 77 along the bottom wall surface 21b and the side surface 77c along the side wall surface 21c, so that balls 81 (other rolling elements) are provided. The ball transfer units 83 are the same as the ball transfer units 73. The balls 81 on the bottom surface 77b can roll on the bottom wall surface 21b (Fig. 9) of the disposal tunnel 21, and the balls 81 on the side surface 77c can roll on the side wall surface 21c (Fig. 9) of the disposal tunnel 21. The balls 81 on the bottom surface 77b and the side surface 77c are arranged in two rows along a straight line extending in the longitudinal direction of the main body 77, similar to the balls 71 on the inclined surface 77a.

[0036] The arrangement and number of ball transfer units 73, 83 on the slope 77a, bottom surface 77b, and side surface 77c may be appropriately determined based on the contact position of the waste package 11, the weight of the waste package 11, and the specifications of the ball transfer units 73, 83. Commercially available ball transfer units may be used as the ball transfer units 73, 83.

[0037] The waste package 11 moves independently within the disposal tunnel 21 while being supported by two pack guides 70, 70 installed at both corners of the bottom of the disposal tunnel 21. At this time, the waste package 11 is slightly spaced from the bottom wall surface 21b (Fig. 9) of the disposal tunnel 21. During the above movement, the cylindrical side surface 11a of the waste package 11 comes into contact with the ball 71 on the inclined surface 77a of the pack guide unit 72, and the ball 71 rolls on the cylindrical side surface 11a, thereby reducing friction between the pack guides 70 and the waste package 11, and the waste package 11 is smoothly guided to the fixed position 11p.

[0038] Next, a geological disposal method for waste packages 11 executed in the geological disposal facility 1 of this embodiment will be described. In this geological disposal method, first, a waste package 11 is fabricated in the surface facility 5 (FIGS. 1 and 2). This waste package 11 is transported to the emplacement position 11p by a transportation method using the transportation system 40 as described above, and then emplaced and disposed of. At this time, the presence of the pack guide 70 described above allows the waste package 11 to move smoothly to the emplacement position 11p within the disposal tunnel 21. If this disposal of waste packages 11 is repeated, the number of waste packages 11 emplaced and disposed of in one disposal tunnel 21 will reach a predetermined planned number. If this happens, the pack guide 70 in that disposal tunnel 21 will no longer be needed, and a unit retrieval process will be executed to retrieve the pack guide unit 72 of the pack guide 70 from that disposal tunnel 21.

[0039] The unit retrieval process will now be described. In the unit retrieval process, as shown in FIG. 11 , a unit retrieval device 79 is disposed, for example, in the access tunnel 9. The pack guide unit 72, sandwiched between the waste package 11 and the disposal tunnel 21, is pulled by the unit retrieval device 79 in the longitudinal direction of the disposal tunnel 21 toward the upstream side. As described above, the pack guide unit 72 has a ball transfer unit 73 mounted on the inclined surface 77a of the main body 77, and ball transfer units 83 mounted on the bottom surface 77b and side surface 77c. Therefore, the ball 71 of the ball transfer unit 73 rolls on the cylindrical side surface 11a of the waste package 11, and the balls 81 of the ball transfer units 83 roll on the bottom wall surface 21b and side wall surface 21c, respectively, allowing the pack guide unit 72 to move relatively easily in the upstream and downstream directions. Therefore, the pack guide unit 72 can be pulled out in the upstream and downstream directions from between the waste package 11 and the disposal tunnel 21. As a result, the pack guide units 72 pulled by the unit retrieval device 79 as described above move continuously upstream as if being pulled out in a string through the gap between the waste package 11 and the disposal tunnel 21 via the cord 78, and are continuously retrieved by the unit retrieval device 79. When the pack guide units 72 are removed, the waste package 11 drops slightly and touches the bottom wall surface 21b of the disposal tunnel 21.

[0040] After all the pack guide units 72 have been retrieved, the disposal tunnel 21 is backfilled as necessary, and the waste packages 11 are buried in the backfill material. The pack guide units 72 retrieved by the unit retrieval device 79 are reused in the pack guide sections 70 of another disposal tunnel 21 that will be used newly.

[0041] The effects of the geological disposal facility 1 and geological disposal method described above will now be explained. Because the access tunnel 9 and the disposal tunnel 21 have different tunnel specifications (such as borehole diameter), the waste package 11 cannot be transported using the same transport equipment. Conventionally, measures such as transferring the waste package 11 between transport equipment have been required. In contrast, in the transportation system 40 of the geological disposal facility 1, the waste package 11 is separably loaded onto the first transport vehicle 47 that travels through the access tunnel 9. Therefore, by separating the waste package 11 from the first transport vehicle 47 at the connection 55 between the access tunnel 9 and the disposal tunnel 21, the waste package 11 can be transported without transfer. In other words, measures such as transferring the waste package 11 from the transport equipment for the access tunnel 9 to the transport equipment for the disposal tunnel 21 are not required.

[0042] Furthermore, at the connecting section 55, the extension directions of the branch tunnel 9b of the access tunnel 9 and the disposal tunnel 21 are aligned. With this configuration, at the connecting section 55, the waste package 11 can be pushed out into the disposal tunnel 21 by controlling the air flow of the blower 51 and the pack holder 47e. Therefore, the waste package 11 can be transported efficiently within the geological disposal facility 1.

[0043] At this time, in the connection section 55, the first transport vehicle 47 is pressed against the step section 56 by the air flow control of the blower 51, and the waste package 11 is further pushed out from the first transport vehicle 47 into the disposal tunnel 21 by the air flow control of the blower 51. In this way, the operation of separating the waste package 11 from the first transport vehicle 47 and introducing it into the disposal tunnel 21 can be performed by the air flow control of the blower 51.

[0044] Furthermore, when viewed from the axial direction (upstream and downstream directions) at the connection portion 55, the outline of the waste package 11 on the loading platform 47h of the first transport cart 47 is positioned so that it does not extend beyond the outline of the disposal tunnel 21, so the waste package 11 is smoothly transferred from the loading platform 47h to the disposal tunnel 21.

[0045] Furthermore, within the disposal tunnel 21, the balls 71 on the slopes 77a of the pack guide unit 72 roll on the cylindrical side surface 11a of the waste package 11, so that the waste package 11 transferred from the first transport vehicle 47 of the access tunnel 9 to the disposal tunnel 21 moves smoothly within the disposal tunnel 21 and reaches the emplacement position 11p. Therefore, the waste package 11 can be transported efficiently within the geological disposal facility 1.

[0046] Another possible method for smoothly transporting the waste package 11 within the disposal tunnel 21 is to use a dedicated gripping device to hold the waste package 11 and transport it within the disposal tunnel 21. However, in this case, the diameter of the disposal tunnel 21 must be increased to accommodate the gripping device. This increases the amount of excavated soil required for the construction of the disposal tunnel 21, which in turn increases construction costs due to increased excavated soil disposal costs, improved support specifications, and increased backfill soil volume. In contrast, the pack guide 70 can also be used when moving the waste package 11 independently within the disposal tunnel 21. For example, the cross-section of the disposal tunnel 21 can be made slightly larger than the waste package 11, and the pack guide 70 can be installed in a relatively small space, such as near a corner of the disposal tunnel 21. As a result, the required cross-sectional area of ​​the disposal tunnel 21 can be reduced, thereby reducing construction costs for the disposal tunnel 21.

[0047] Furthermore, in the pack guide unit 72, ball transfer units 83 are installed not only on the slope 77a of the main body 77, but also on the bottom surface 77b and side surface 77c. This makes it possible to retrieve the used pack guide unit 72 by pulling it from the upstream side in the unit retrieval process. This prevents the pack guide 70 from being left behind in the disposal tunnel 21 together with the waste package 11, and prevents the use of the pack guide 70 from compromising the long-term safety of the geological disposal facility 1.

[0048] The present invention can be implemented in various forms, including the above-described embodiment, with various modifications and improvements based on the knowledge of those skilled in the art. It is also possible to configure modified examples by utilizing the technical matters described in the above-described embodiment. The configurations of the respective embodiments may be used in appropriate combination.

[0049] For example, in the above-described embodiment, the layout of the disposal section 3 (dead-end type / panel type) and the transportation method in the disposal tunnel 21 (pneumatic transportation / movement by inclination) may be changed as appropriate. Note that, if the transportation method in the disposal tunnel 21 is pneumatic transportation, the disposal tunnel 21 does not need to be inclined. For example, if the transportation method in the disposal tunnel 21 is pneumatic transportation, the airflow control by the blower 51 continues even after the waste package 11 is transferred from the loading platform 47h of the first transport vehicle 47 to the disposal tunnel 21 by the airflow of the blower 51. The first transport vehicle 47 is then pressed against the step portion 56 by the airflow of the blower 51 and stops there. Meanwhile, the disposal tunnel 21, having been transferred to the disposal tunnel 21, receives the airflow from the blower 51 through the through-hole 47d of the first transport vehicle 47 and travels downstream within the disposal tunnel 21. Even in this case, the waste package 11 moves smoothly through the disposal tunnel 21 and reaches the emplacement position 11p due to the presence of the pack guide 70. Furthermore, if the layout of the disposal section 3 is a dead-end type and the transport method in the disposal tunnel 21 is a pneumatic transport method, for example, a duct or the like may be provided to connect the tip of the disposal tunnel 21 with the connecting tunnel 9 in order to properly move air during pneumatic transport.

[0050] In the above-described embodiment, the access tunnel 9 has a rectangular cross section and the disposal tunnel 21 has a horseshoe-shaped cross section. However, this is not limiting, and the cross-sectional shapes of each tunnel can be modified as appropriate. In this case, the shape of the seal plate 47f of the first transport vehicle 47 may be adjusted to match the cross-sectional shape of the access tunnel 9. Furthermore, the waste packages 11 loaded on the first transport vehicle 47 may be positioned so that they do not extend beyond the contour of the disposal tunnel 21 when viewed axially at the connection portion 55. The cross-sectional shape of the disposal tunnel 21 may be modified as appropriate, provided that a pack guide 70 can be installed in the gap between the disposal tunnel 21 and the waste package 11. In this case, it is not essential that the pack guide 70 have a cross section that is an isosceles right triangle; the shape may be determined to correspond to the gap between the disposal tunnel 21 and the waste package 11.

[0051] Furthermore, the mechanism for rolling the numerous balls 71 is not limited to the ball transfer unit 73, and other ball bearing elements may be used. For example, instead of the multiple ball transfer units 73, a unit having a structure such as a linear ball slide that circulates the numerous balls 71 within the unit may be used. Furthermore, instead of the balls 71, 81, rollers 74 (rolling elements) may be used, as shown in Figure 12. The rotation axis direction of the rollers 74 is set so that they roll in the movement direction (axial direction) of the waste package 11 in the disposal tunnel 21. [Explanation of symbols]

[0052] 1...geological disposal facility, 11...waste package, 11a...cylindrical side surface, 11p...emplacement position, 21...disposal tunnel, 21b...bottom wall surface, 21c...side wall surface, 72...pack guide unit, 71...ball (rolling element), 73...ball transfer unit, 77...main body.

Claims

1. A geological disposal facility for geological disposal of radioactive waste, a disposal tunnel in which a cylindrical waste package containing the radioactive waste is placed and disposed of in a horizontal manner; a pack guide unit that is installed in the disposal tunnel and guides the waste package, which moves independently within the disposal tunnel, to a fixed position; The pack guiding unit is A geological disposal facility comprising: a main body portion disposed on the inner wall surface of the disposal tunnel; and a plurality of rolling elements provided on the main body portion and rolling on the cylindrical side surface of the waste package.

2. The pack guiding unit is 2. The geological disposal facility according to claim 1, further comprising a plurality of other rolling elements provided in the main body and rolling on the inner wall surface of the disposal tunnel.

3. 2. A geological disposal facility as described in claim 1, wherein the disposal tunnel comprises a bottom wall surface and side wall surfaces rising from both ends of the bottom wall surface, and the pack guide units are installed along two corners of the bottom wall surface and the side wall surfaces.

4. 3. A geological disposal method for geologically disposing of radioactive waste in the geological disposal facility according to claim 2, comprising: A geological disposal method comprising a unit retrieval step in which, after a predetermined number of waste packages have been placed in the disposal tunnel by guidance using the pack guiding unit, the pack guiding unit is withdrawn in the longitudinal direction of the disposal tunnel to retrieve them.

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