JP2015087326A - Jet fuel discharge structure and cast storage building using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time for burning a jet fuel entering a cask storage building owing to collision of an aircraft against the cask storage building.SOLUTION: A jet fuel discharge mechanism 30a is provided in a cask storage building 11 that stores casks 10, and that includes a first air supply port 22a and a second air supply port 22b for introducing ambient air AR into a space SP in which the casks 10 are stored, and a first exhaust port 26a and a second exhaust port 26b for discharging the ambient air AR from the space SP. The jet fuel discharge mechanism 30a includes: liquid collection sections 32g, 32e, 32f provided on at least either a floor 12 in part of areas of which the casks 10 are mounted or a radiation shield 27 provided upward U of the floor 12, and collecting a jet fuel entering an interior of the cask storage building 11; a tank 50 accumulating the collected jet fuel; and a pipe 36 connecting the liquid collection sections 32g, 32e, and 32f to the tank 50.

Description

  The present invention relates to a jet fuel discharge structure and a cask storage building using the same.

  A spent nuclear fuel assembly used in a nuclear power plant or the like and taken out from the reactor after being loaded and burned in the nuclear reactor is referred to as a recycled fuel assembly. Since this recycle fuel assembly contains a large amount of radioactive material, it is cooled in a cooling pool over a predetermined period. After that, when the recycled fuel assembly is cooled for a predetermined period, it is stored in a cask that is a radioactive substance storage container, transported to a cask storage building by a truck or the like, and stored for a long period of time. As such a cask storage building, there exists a thing described in the following patent document, for example.

Japanese Patent Publication No. 04-44958

  In recent years, demands for dealing with severe accidents for nuclear facilities have been made clear, and the need for countermeasures against intentional aircraft collisions has increased. When an aircraft collision with a cask storage building occurs, jet fuel leaks from the aircraft and can enter the building and burn.

The cask storage building is provided with a plurality of air supply ports and exhaust ports. These air supply and exhaust openings have a large opening area of about 20 m ² , so that when an aircraft collision occurs and fuel leaks from the aircraft, the cask storage building is connected to the air supply and exhaust openings. There is a possibility that jet fuel may enter and burn inside. Further, when the jet fuel burns, the cask is exposed to a flame and a high temperature, and if this state lasts for a long time, the safety function of the cask may be lowered.

  An object of the present invention is to shorten the time required for burning jet fuel that has entered the cask storage building due to an aircraft collision with the cask storage building.

  The jet fuel discharge structure according to the present invention is a structure provided in a cask storage building that stores a cask and has an air supply port for introducing outside air into a space in which the cask is stored and an exhaust port for discharging outside air from the space. The jet fuel, which is provided on at least one of a floor on which the cask is placed in a partial area and a radiation shield provided above the floor, enters the inside of the cask storage building. A liquid collection part that collects from at least one of the upper surface of the radiation shield and the upper surface of the radiation shield, a tank that stores the jet fuel collected in the liquid collection part, the liquid collection part and the tank are connected, and the liquid collection And a pipe for guiding the jet fuel collected in the section to the tank.

  With such a configuration, the jet fuel discharge structure according to the present invention can discharge jet fuel to the outside of the cask storage building even when the jet fuel enters the cask storage building. For this reason, the time for the jet fuel that has entered the cask storage building to burn can be shortened.

  The tank is preferably installed below the floor. Thereby, the tank can be protected from the collision of the aircraft by the cask storage building. For this reason, the jet fuel discharge structure can protect the function of discharging the jet fuel to the outside of the cask storage building.

  The liquid collection part is preferably a liquid collection pipe that has an opening in at least one of the upper surface of the floor and the upper surface of the radiation shield and guides the jet fuel that has entered the opening to the pipe. . Thereby, the jet fuel that has entered the inside of the cask storage building can be collected by the collecting pipe and discharged to the outside of the cask storage building.

  It is preferable that the opening is provided in a portion different from a passage of a device that conveys the cask. Thereby, it can suppress that conveyance of a cask is inhibited by the opening part of a liquid collection pipe | tube.

  The liquid collection part is a groove provided on at least one of the upper surface of the floor and the upper surface of the radiation shield, and the pipe preferably has an opening on at least one of a bottom surface and a side surface of the groove. Thereby, the jet fuel that has entered the inside of the cask storage building can be collected in the groove and discharged to the outside of the cask storage building.

  The cask storage building has an air supply duct that extends downward from the air supply port and guides outside air from the air supply port to a space in which the cask of the cask storage building is stored, and the groove Is preferably formed by making the upper surface of the floor below the air supply duct lower than the upper surface of the floor in the region where the cask is placed. As a result, the jet fuel that has entered through the air supply port is collected in a groove formed by lowering the upper surface of the floor below the air supply duct to be lower than the upper surface of the floor in the area where the cask is placed. It can be discharged outside the building.

  It is preferable that the groove is provided in a portion different from a passage of a device that conveys the cask. Thereby, it can suppress that conveyance of a cask is inhibited by a groove | channel.

  When the level of the liquid level of the jet fuel staying above the liquid collection part is reduced to the opening part of the liquid collection pipe or the pipe, it is preferable to close the opening part. As a result, the flow of the jet fuel to the liquid collection part is stopped, and when the height of the liquid level of the jet fuel staying above the liquid collection part falls to the opening of the liquid collection pipe or pipe, the liquid collection part It is possible to suppress the intrusion of air into the inside of the liquid and to suppress the combustion of the inside of the liquid collecting part.

  When the height of the liquid level of the jet fuel staying above the liquid collection part is reduced to the opening of the liquid collection pipe or the pipe, it is formed in at least one of the inside of the liquid collection part and the inside of the tank. It is preferable to blow in an inert gas. Thereby, the air which entered the inside of the liquid collection part can be replaced with the inert gas. For this reason, it can suppress that jet fuel burns inside a liquid collection part.

  The cask storage building has an air supply duct that extends downward from the air supply port and guides outside air from the air supply port to a space in which the cask of the cask storage building is stored. It is preferable to have a weir protruding from the floor between the upper surface of the floor below the air duct and the upper surface of the floor in the area where the cask is placed. Thereby, it is possible to suppress the jet fuel that has entered from the air supply port from reaching the area where the cask is placed.

  It is preferable to have a pump for pumping out the jet fuel stored in the tank from the tank. Thereby, it is possible to prevent the tank from being filled with jet fuel and the jet fuel from being discharged slowly.

  The pump is preferably installed below the floor. Thereby, the pump can be protected from the collision of the aircraft by the cask storage building. For this reason, the jet fuel discharge structure can protect the function of discharging the jet fuel to the outside of the cask storage building.

  It is preferable that the pump automatically starts operation when a fire is detected by a sensor installed in a space where the cask is stored. By doing in this way, it can control more suitably that a tank becomes full with jet fuel, and discharge of jet fuel is overdue.

  It is preferable that when the pump senses that the jet fuel stored in the tank has reached a predetermined amount, the pump automatically starts operation. By doing in this way, it can control more suitably that a tank becomes full with jet fuel, and discharge of jet fuel is overdue.

  The cask storage building according to the present invention includes any one of an air supply port that stores cask and introduces outside air into a space in which the cask is stored, an exhaust port that discharges outside air from the space, and the jet fuel discharge structure described above. Or one.

  With such a configuration, the cask storage building according to the present invention can discharge the jet fuel to the outside of the cask storage building by the jet fuel discharge structure even when the jet fuel enters the inside of the cask storage building. For this reason, the time for the jet fuel that has entered the cask storage building to burn can be shortened. Therefore, it is possible to effectively suppress the deterioration of the safety function of the cask and the durability of the cask and the cask storage building due to the jet fuel fire.

  INDUSTRIAL APPLICABILITY The present invention can shorten the time for jet fuel that has entered the cask storage building due to an aircraft collision to the cask storage building to burn.

FIG. 1 is a longitudinal sectional view showing an internal structure of a cask storage building according to Embodiment 1 of the present invention. FIG. 2 is a horizontal sectional view showing the internal structure of the cask storage building according to Embodiment 1 of the present invention. FIG. 3 is a longitudinal sectional view showing the flow of cooling air in the cask storage building according to Embodiment 1 of the present invention. FIG. 4 is a cross-sectional view showing the jet fuel discharge structure according to Embodiment 1 of the present invention. FIG. 5 is a plan view showing grooves provided on the upper surface of the radiation shield included in the cask storage building according to the first embodiment of the present invention. FIG. 6 is a perspective view showing grooves and pipes provided on the upper surface of the radiation shield included in the cask storage building according to Embodiment 1 of the present invention. FIG. 7 is a perspective view showing grooves and piping provided on the upper surface of the floor of the cask storage building according to Embodiment 1 of the present invention. FIG. 8 is a perspective view showing a liquid collection pipe and piping provided on the upper surface of the floor of the cask storage building according to Embodiment 1 of the present invention. FIG. 9 is a cross-sectional view showing a jet fuel discharge structure according to Embodiment 2 of the present invention. FIG. 10 is a perspective view illustrating a liquid collection pipe and a pipe provided on the upper surface of the radiation shield included in the cask storage building according to the second embodiment of the present invention. FIG. 11 is a perspective view showing a weir, a collecting pipe, and piping provided on the upper surface of the floor of the cask storage building according to Embodiment 2 of the present invention.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view showing the internal structure of the cask storage building according to the first embodiment. FIG. 2 is a horizontal sectional view showing the internal structure of the cask storage building according to the first embodiment. In the present embodiment, the direction opposite to the direction in which gravity acts is the upper U, and the direction in which gravity acts is the lower D.

  As shown in FIGS. 1 and 2, the cask storage building 11 of Embodiment 1 includes a floor 12, a ceiling 13, a side wall 14, a pillar 15, an air supply port 22, an air supply duct 24, an exhaust port 26, and a radiation shield 27. Have The floor 12, the ceiling 13, the side wall 14, the pillar 15, the air supply port 22, the air supply duct 24, the exhaust port 26, and the radiation shield 27 are made of concrete. Further, in at least one of the floor 12, the ceiling 13, the side wall 14, the column 15, and the radiation shield 27, a reinforcing bar or a steel frame may be embedded in the concrete. Thereby, the intensity | strength of at least 1 of the floor 12, the ceiling 13, the side wall 14, the pillar 15, and the radiation shield 27 can be improved.

  In the present embodiment, the floor 12 is a member installed on the ground 8 side by a predetermined method. In the present embodiment, the floor 12 is a plate-like member, but the floor 12 is not limited to such. In the upper surface 12S of the floor 12, the first placement area A1 provided on the first side wall 14a side and the second placement area A2 provided on the second side wall 14b side include a plurality of casks at predetermined intervals. 10 is placed. Each cask 10 contains a recycled fuel assembly. Between the first placement area A1 and the second placement area A2, a non-placement area B where the cask 10 is not placed is provided.

  Around the floor 12, a side wall 14, that is, a first side wall 14a and a second side wall 14b facing each other, and a third side wall 14c and a fourth side wall 14d facing each other are provided. The floor 12 is surrounded by a first side wall 14a, a second side wall 14b, a third side wall 14c, and a fourth side wall 14d. The floor 12 is provided with a plurality of pillars 15. A ceiling 13 is provided at the upper ends of the plurality of side walls 14 and the plurality of columns 15. The ceiling 13 is supported by at least one of the plurality of side walls 14 and the plurality of pillars 15.

  The floor 12, the ceiling 13 and the side wall 14 have a radiation shielding function. The cask storage building 11 has a space SP formed by the floor 12, the ceiling 13, and the side wall 14, and the cask 10 is stored in this space SP. The cask storage building 11 has a strength that can withstand an aircraft collision or a strength that does not affect the safety function of the cask 10 even if it is partially damaged by an aircraft collision.

  The cask storage building 11 is provided with a first air supply port 22a at the upper part of the first side wall 14a and a second air supply port 22b at the upper part of the second side wall 14b. In the present embodiment, the first air supply port 22 a and the second air supply port 22 b are provided adjacent to the ceiling 13. The cask storage building 11 is provided with a first partition wall 23a facing the inner surface 14Ia side of the first side wall 14a and a second partition wall 23b facing the inner surface 14Ib side of the second side wall 14b. The first partition wall 23a and the second partition wall 23b have an upper end fixed to the ceiling 13 and a lower end disposed with a predetermined gap from the upper surface 12S of the floor 12. The first partition wall 23a and the second partition wall 23b are made of concrete. Further, a reinforcing bar or a steel frame may be embedded in at least one of the first partition wall 23a and the second partition wall 23b. Thereby, the intensity | strength of at least 1 of the 1st partition wall 23a and the 2nd partition wall 23b can be improved.

  A first air supply duct 24a is formed by the first side wall 14a, the third side wall 14c, the fourth side wall 14d, and the first partition wall 23a. A second air supply duct 24b is formed by the second side wall 14b, the third side wall 14c, the fourth side wall 14d, and the second partition wall 23b. The first air supply duct 24a extends downward D from the first air supply port 22a, and the second air supply duct 24b extends downward D from the second air supply port 22b.

  The first air supply duct 24a connects the first air supply port 22a and the space SP formed by the floor 12, the ceiling 13 and the side wall 14 of the cask storage building 11, that is, the space SP in which the cask 10 is stored. ing. The second air supply duct 24b connects the second air supply port 22b and the space SP formed by the floor 12, the ceiling 13 and the side wall 14 of the cask storage building 11, that is, the space SP in which the cask 10 is stored. ing.

  In this embodiment, the cask storage building 11 is equidistant from both the first side wall 14a and the second side wall 14b in the central portion of the ceiling 13, that is, the ceiling 13, and the third side wall 14c and the fourth side wall 14d. The ventilation tower 25 is provided so as to protrude upward U at a position that is equidistant from both. The ventilation tower 25 is not necessarily provided at the center of the ceiling. The ventilation tower 25 is provided with a first exhaust port 26a and a second exhaust port 26b.

  The first exhaust port 26a is connected to the outside of the cask storage building 11 and the space SP formed by the floor 12, the ceiling 13 and the side wall 14 of the cask storage building 11, that is, the space SP in which the cask 10 is stored. The second exhaust port 26b is connected to the outside of the cask storage building 11 and the space SP formed by the floor 12, the ceiling 13 and the side wall 14 of the cask storage building 11, that is, the space SP in which the cask 10 is stored.

  Inside the cask storage building 11, a radiation shield 27 is disposed in a region connecting the plurality of casks 10 placed on the upper surface 12S of the floor 12 and the first exhaust port 26a and the second exhaust port 26b. . Specifically, the radiation shield 27 is arranged in the radiation region Sa surrounded by the region line La1 and the region line La2 and in the radiation region Sb surrounded by the region line Lb1 and the region line Lb2. The radiation shield 27 is supported by the third side wall 14 c, the fourth side wall 14 d, and the plurality of pillars 15, and shields the radiation emitted from each cask 10. In the cask storage building 11, the radiation shield 27 may not be installed inside.

  The area line La1 is a line segment connecting the cask 10 placed in the position closest to the first side wall 14a and the second exhaust port 26b among the cask 10 placed in the first placement area A1. It is. One end of the region line La1 is a point closest to the first side wall 14a on the end portion of the upper surface of the cask 10 placed at a position closest to the first side wall 14a, and the other end of the region line La1 is Among the points on the two exhaust ports 26b, the length of the region line La1 is the maximum.

  The area line La2 is a line segment extending from the cask 10 placed at the position closest to the second side wall 14b to the second exhaust port 26b among the plurality of casks 10 placed in the first placement area A1. It is. One end of the region line La2 is a point closest to the second side wall 14b on the end of the lower surface of the cask 10 placed at a position closest to the second side wall 14b, and the other end of the region line La2 is Among the points on the second exhaust port 26b, the length of the region line La2 is the maximum.

  The area line Lb1 is a line segment connecting the cask 10 placed in the position closest to the second side wall 14b and the first exhaust port 26a among the cask 10 placed in the second placement area A2. It is. One end of the region line Lb1 is a point closest to the second side wall 14b on the end portion of the upper surface of the cask 10 placed at the position closest to the second side wall 14b, and the other end of the region line Lb1 is Among the points on one exhaust port 26a, the length of the region line Lb1 is the maximum.

  The region line Lb2 is a line segment extending from the cask 10 placed at the position closest to the first side wall 14a to the first exhaust port 26a among the plurality of caskes 10 placed in the second placement region A2. It is. One end of the region line Lb2 is a point closest to the first side wall 14a on the end of the lower surface of the cask 10 placed at a position closest to the first side wall 14a, and the other end of the region line Lb2 is Of the points on the first exhaust port 26a, the length of the region line Lb2 is the maximum.

  Radiation is emitted from all the casks 10 placed in the first placement area A1 and the second placement area A2 in all directions. Radiation heading straight from the cask 10 toward the first exhaust port 26 a or the second exhaust port 26 b is shielded by the radiation shield 27. Radiation that goes straight from the cask 10 to other than the first exhaust port 26a and the second exhaust port 26b is shielded by the floor 12, the ceiling 13, the side wall 14, the ventilation tower 25, the first partition wall 23a, and the second partition wall 23b. . For this reason, the floor 12, the ceiling 13, the side wall 14, the ventilation tower 25, the first partition wall 23a, and the second partition wall 23b reliably prevent leakage of radiation emitted from each cask 10 in all directions. The

  FIG. 3 is a longitudinal sectional view showing a flow of cooling air in the cask storage building according to the first embodiment. The flow of cooling air in the cask storage building according to Embodiment 1 of the present invention will be described with reference to FIG.

  As shown in FIG. 3, the outside air AR is taken in from the first air supply port 22a and the second air supply port 22b, and the space SP in which the cask 10 is stored by the first air supply duct 24a and the second air supply duct 24b. Then, the plurality of caskes 10 arranged on the upper surface 12S of the floor 12 are cooled. The outside air AR that has cooled the plurality of casks 10 rises while bypassing the radiation shield 27, and is discharged from the first exhaust port 26 a and the second exhaust port 26 b to the outside of the cask storage building 11. Thus, each cask 10 is cooled by the outside air AR.

  In this case, since the air heated by cooling the cask 10 rises, a flow is generated that is discharged to the outside from the first exhaust port 26a and the second exhaust port 26b. For this reason, the pressure inside the cask storage building 11, more specifically, the pressure inside the space SP formed by the floor 12, the ceiling 13, and the side wall 14 of the cask storage building 11 is greater than the pressure outside the cask storage building 11. Get smaller. For this reason, the outside air AR is sucked from the first air supply port 22a and the second air supply port 22b, and taken into the cask storage building 11 through the first air supply duct 24a and the second air supply duct 24b. . The outside air AR sucked from the first air supply port 22a and the second air supply port 22b is guided to the region where the cask 10 is placed by the first air supply duct 24a and the second air supply duct 24b. For this reason, the cask storage building 11 can cool the cask 10 reliably.

  FIG. 4 is a cross-sectional view showing the jet fuel discharge structure according to the first embodiment. FIG. 5 is a plan view showing grooves provided on the upper surface of the radiation shield included in the cask storage building according to the first embodiment of the present invention. FIG. 6 is a perspective view showing grooves and pipes provided on the upper surface of the radiation shield included in the cask storage building according to Embodiment 1 of the present invention. FIG. 7 is a perspective view showing grooves and piping provided on the upper surface of the floor of the cask storage building according to Embodiment 1 of the present invention. FIG. 8 is a perspective view showing a liquid collection pipe and piping provided on the upper surface of the floor of the cask storage building according to Embodiment 1 of the present invention. A jet fuel discharge structure according to Embodiment 1 of the present invention will be described with reference to FIGS. 4, 5, 6, 7, and 8. The structure on the second exhaust port 26b side will be described as an example, but the structure on the first exhaust port 26a side is the same.

  As shown in FIG. 4, the jet fuel discharge structure 30 a according to the first embodiment includes a liquid collection part 32 d provided on the upper surface 27 </ b> S of the radiation shield 27, a liquid collection part 32 e provided on the upper surface 12 </ b> S of the floor 12, and a liquid collection part. It has a liquid part 32f. A tank 50 and a pump 60 are installed below the floor D. In the tank 50, the jet fuel collected by the liquid collection part 32d, the liquid collection part 32e, and the liquid collection part 32f is stored. The pump 60 pumps out the jet fuel stored in the tank 50 from the tank 50. For this reason, it can suppress that the tank 50 becomes full with jet fuel, and discharge | emission of jet fuel is delayed. The tank 50 and the pump 60 are connected via a pipe 55 as a passage through which fluid passes.

  The liquid collection part 32d and the tank 50 are connected via pipes 36r, 36s, 36t, 36u, and 36v. The liquid collection unit 32e and the tank 50 are connected via pipes 36z, 36u, and 36v. The liquid collection part 32f and the tank 50 are connected via pipes 36w, 36x, and 36y. When the pipes 36y are not distinguished from the pipes 36s, they are appropriately referred to as pipes 36.

  The tank 50 and the pump 60 are installed below the floor 12. With such a structure, the jet fuel in the pipe 36 is guided to the inside of the tank 50 using gravity. For this reason, there is no need to install a pump or the like, which is economical. In addition, since the tank 50 and the pump 60 are installed below the floor 12 of the cask storage building 11, they are protected by the cask storage building 11 when an aircraft collides. For this reason, the function of the jet fuel discharge structure 30a discharging the jet fuel to the outside of the cask storage building 11 is protected.

  As shown in FIGS. 4, 5, and 6, the liquid collection part 32 d has a groove 38 d provided on the upper surface 27 </ b> S of the radiation shield 27. As shown in FIGS. 4 and 6, the groove 38 d is formed by lowering the height of a part of the upper surface 27 </ b> S of the radiation shield 27 from the other part. Here, the upper surface 27 </ b> S of the radiation shield 27 is a surface facing upward U of the surface of the radiation shield 27. Further, as shown in FIG. 5, the groove 38 d is provided so as to surround the plurality of pillars 15. As shown in FIGS. 4 and 6, a pipe 36r is opened on the bottom surface 38Bd of the groove 38d. That is, the pipe 36r has an opening 40d. The opening 40d of the pipe 36r may be provided on the side surface 38Ld of the groove 38d. The pipe 36r may open to the side surface 38Ld of the groove 38d. The groove 38d is arranged so that the radiation shielding function of the radiation shielding body 27 is ensured.

  As shown in FIG. 6, the lower end of the pipe 36r is attached to one end of an L-shaped pipe joint 37i, and the other end of the L-shaped pipe joint 37i is connected to the pipe 36s. As shown in FIG. 6, the pipe 36 s extends in the horizontal direction toward the column 15 inside the radiation shield 27. The pipe 36s is connected to the pipe 36t via an L-shaped pipe joint 37j provided at a position in contact with the column 15. In the present embodiment, the pipe 36t is attached in contact with the column 15 and extends from the radiation shield 27 to the floor 12 in the vertical direction. As shown in FIG. 8, the lower end of the pipe 36t is connected to the pipe 36u via a T-shaped pipe joint 37k. The pipe 36u extends in the horizontal direction inside the floor 12, and is connected to the pipe 36v shown in FIG. 4 via an L-shaped pipe joint (not shown). For example, the pipe 36 v extends in the vertical direction inside the floor 12 and below the floor 12, and the lower end of the pipe 36 v is connected to the tank 50.

  As shown in FIGS. 4 and 7, the liquid collection part 32e has a groove 38e. The groove 38e is formed so that the upper surface 12S of the floor 12 below the second air supply duct 24b is located on the upper surface 12S of the floor 12 in the first placement region A1 and the second placement region A2. It is formed by making it lower than 12S. The upper surface of the floor 12 is a surface facing the upper side U of the surface of the floor 12. The upper surface 12S of the floor 12 in the first placement area A1 and the second placement area A2 is preferably 0.02 m to 0.5 m higher than the bottom face 38Be of the groove 38e.

  In the present embodiment, a pipe 36w is opened on the bottom surface 38Be of the groove 38e. That is, the pipe 36w has an opening 40e. The opening 40e of the pipe 36w may be provided on the side surface 38Le of the groove 38e. The lower end of the pipe 36w is connected to the pipe 36x via an L-shaped pipe joint 37p. The pipe 36x extends in the horizontal direction inside the floor 12, and is connected to the pipe 36y shown in FIG. 4 via an L-shaped pipe joint (not shown). As shown in FIG. 4, the pipe 36 y extends in the vertical direction inside the floor 12 and the foundation (not shown) installed below the floor 12, and the lower end of the pipe 36 y is connected to the tank 50. Has been.

  As shown in FIGS. 4 and 8, the liquid collection part 32 f has a liquid collection pipe 34 f embedded in the floor 12. The liquid collection pipe 34f extends in the vertical direction and opens on the upper surface 12S of the floor 12. That is, the liquid collection pipe 34f has an opening 40f. The lower end of the liquid collecting pipe 34f is attached to one end of an L-shaped pipe joint 37q, and the other end of the L-shaped pipe joint 37q is connected to a pipe 36z. The pipe 36z extends horizontally inside the floor 12 and is connected to the pipe 36u via a T-shaped pipe joint 37k. The pipe 36u extends in the horizontal direction inside the floor 12, and is connected to the pipe 36v via an L-shaped pipe joint (not shown). The pipe 36v extends in the vertical direction inside the floor 12 and underground, and the lower end of the pipe 36v is connected to the tank 50.

  It is preferable that the groove 38e provided in the liquid collection part 32e and the opening 40f of the liquid collection pipe 34f provided in the liquid collection part 32f are provided in a part different from the passage of the apparatus for conveying the cask 10. With such a structure, it is possible to prevent the conveyance of the cask 10 from being hindered by the groove 38e of the liquid collection part 32e or the opening 40f of the liquid collection pipe 34f.

  In the first embodiment of the present invention, the liquid collection pipe 34f, the pipe 36 (36s, 36t, 36z, 36u, 36v, 36w, 36x, 36y, 36r) and the pipe joint 37 (37i, 37q, 37k, 37p, 37j) ) Is formed with a male screw or a female screw (not shown), and the male screw formed on the other side is screwed into the female screw formed on one side, whereby the liquid collection pipe 34f or the pipe 36, and the pipe joint 37 However, the method of connecting the liquid collection pipe 34f or the pipe 36 and the pipe joint 37 is not limited to this.

  Part of the jet fuel that has entered from at least one of the first exhaust port 26 a and the second exhaust port 26 b falls to the upper surface 27 </ b> S of the radiation shield 27. A part of the jet fuel that has reached the upper surface 27S of the radiation shield 27 is collected by the groove 38d of the liquid collection part 32d, and guided to the inside of the tank 50 by the pipes 36r, 36s, 36t, 36u, and 36v. The jet fuel stored in the tank 50 is pumped out by the pump 60 via the pipe 55 and guided to a tank or the like installed in a place that is not easily affected by the jet fuel fire.

  Part of the jet fuel that has entered from the first air inlet 22a or the second air inlet 22b is collected inside the groove 38e. The jet fuel collected into the groove 38e flows into the opening 40e of the pipe 36w and is guided into the tank 50 by the pipes 36w, 36x, and 36y. The jet fuel stored in the tank 50 is pumped out by the pump 60 via the pipe 55 and guided to a tank or the like installed in a place that is not easily affected by the jet fuel fire.

  Of the jet fuel that has entered from at least one of the first exhaust port 26a and the second exhaust port 26b, the jet fuel that has not been collected in the groove 38d of the liquid collection part 32d provided on the upper surface 27S of the radiation shield 27 is radiation. It falls from the end of the shield 27, the ceiling 13, etc., and reaches the upper surface 12S of the floor 12. In addition, when a large amount of jet fuel enters from the first air supply port 22a or the second air supply port 22b, the jet fuel may overflow from the groove 38e. The jet fuel overflowing from the groove 38e reaches the upper surface 12S of the floor 12 in the first placement area A1 and the second placement area A2.

  At least a part of the jet fuel that has reached the upper surface 12S of the floor 12 is collected by the opening 40f of the liquid collection pipe 34f, and guided to the inside of the tank 50 by the liquid collection pipe 34f and the pipes 36z, 36u, and 36v. The jet fuel stored in the tank 50 is pumped out by the pump 60 via the pipe 55 and guided to a tank (not shown) or the like installed in a place that is not easily affected by the jet fuel fire.

  For this reason, the jet fuel discharge structure 30 a can discharge the jet fuel that has entered the inside of the cask storage building 11 to the outside of the cask storage building 11. Therefore, the jet fuel discharge structure 30a can shorten the time for jet fuel to burn. The jet fuel that has entered from at least one of the first exhaust port 26a and the second exhaust port 26b is collected by the liquid collection part 32d, and the jet fuel that has entered from the second air supply port 22b is collected by the liquid collection part 32e. It is possible to suppress the jet fuel from reaching the region where the cask 10 is placed on the upper surface 12S of the twelve. Therefore, even when jet fuel burns inside the cask storage building 11, the combustion time of the jet fuel around the cask 10 is shortened, and a reduction in heat dissipation efficiency of the cask 10 and a reduction in durability of the cask 10 are suppressed.

  Since the jet fuel discharge structure 30a according to the first embodiment is provided with grooves 38d on the upper surface 27S of the radiation shield 27 so as to surround the plurality of columns 15, the first exhaust port 26a and the second exhaust port 26b It is possible to suppress the jet fuel that has entered from at least one from falling from the end of the radiation shield 27 and reaching the first placement area A1 and the second placement area A2.

  The pump 60 is preferably started automatically when a fire is detected by the sensor 80 installed in the space SP in which the cask 10 is stored. For example, a fire alarm or the like can be used as the sensor 80. By doing in this way, it can suppress more suitably that discharge of jet fuel from liquid collection part 32d etc. stagnate as a result of tank 50 becoming full with jet fuel. Moreover, when the jet fuel in the tank 50 reaches a predetermined amount, the pump 60 is preferably started automatically. By doing in this way, it can suppress more suitably that discharge of jet fuel from liquid collection part 32d etc. stagnate as a result of tank 50 becoming full with jet fuel. The predetermined amount is an amount smaller than an amount that fills the tank 50. The predetermined amount can be, for example, about 70% to 80% when the tank 50 is full, but is not limited thereto.

  When the intrusion of the jet fuel into the cask storage building 11 is stopped, the inflow of the jet fuel to the liquid collection part 32d, the liquid collection part 32e, or the liquid collection part 32f is stopped after a certain time has passed. For this reason, air may enter the inside of the liquid collection part 32d, the liquid collection part 32e, or the liquid collection part 32f, and the inside of the jet fuel discharge structure 30a may burn. As measures to suppress this, the liquid collection part 32d, the liquid collection part 32e or the liquid collection part 32f is closed and an inert gas is blown into the liquid collection part 32d, the liquid collection part 32e or the liquid collection part 32f. Can be mentioned. In particular, when the pipe 36r opens to the side surface 38Ld of the groove 38d or when the pipe 36w opens to the side surface 38Le of the groove 38e, air easily enters the liquid collection part 32d or the liquid collection part 32e. It is particularly effective.

  For example, the height of the level of the jet fuel staying above the bottom surface 38Bd of the groove 38d of the liquid collection part 32d provided on the upper surface 27S of the radiation shield 27 is as high as the opening 40d of the pipe 36r of the groove 38d. In the case of lowering, the opening 40d of the pipe 36r that opens to the bottom surface 38Bd of the groove 38d is closed by a member such as a shutter that operates by the combustion heat of jet fuel, or the opening 40d of the pipe 36r is closed by a valve or the like. You may make it do. In this way, when there is no jet fuel remaining in the upper portion U of the bottom surface 38Bd of the groove 38d, air passes through the pipes 36r, 36s, 36t, 36u, and 36v from the opening 40d of the bottom surface 38Bd of the groove 38d. Intrusion into the tank 50 can be suppressed. As a result, the possibility that the jet fuel in the tank 50 burns can be reduced. The same applies to the liquid collection part 32e provided on the upper surface 12S of the floor 12 and the liquid collection part 32f provided on the upper surface 12S of the floor 12.

  An inert gas may be blown into at least one of the inside of the liquid collection part 32d, the liquid collection part 32e, or the liquid collection part 32f and the inside of the tank 50. By blowing the inert gas, the air that has entered the liquid collecting part 32d, the liquid collecting part 32e, or the liquid collecting part 32f is replaced with the inert gas, and as a result, oxygen can be shut off. For this reason, it can suppress that jet fuel burns inside the liquid collection part 32d, the liquid collection part 32e, or the liquid collection part 32f. A fire extinguishing agent may be injected into at least one of the inside of the liquid collection part 32d, the liquid collection part 32e, or the liquid collection part 32f and the inside of the tank 50 instead of the inert gas. In addition, you may use together the countermeasure mentioned above suitably.

  During normal times when no jet fuel fire has occurred, the jet fuel discharge structure 30a according to the first embodiment collects spring water, rainwater, condensed water, and the like that have entered the cask storage building 11 and then to the outside of the cask storage building 11. It can also be used as a facility for draining. By doing in this way, facilities are rationalized and it is possible to suppress an increase in construction costs and maintenance costs. It is reasonable to add no emergency equipment. The jet fuel discharge structure 30a according to the first embodiment is preferably made of a material that is not corroded by the jet fuel. Examples of materials that are not corroded by jet fuel include SUS, titanium, and fluororesin.

(Embodiment 2)
FIG. 9 is a cross-sectional view showing a jet fuel discharge structure according to Embodiment 2 of the present invention. FIG. 10 is a perspective view illustrating a liquid collection pipe and a pipe provided on the upper surface of the radiation shield included in the cask storage building according to the second embodiment of the present invention. FIG. 11 is a perspective view showing a weir, a liquid collection pipe, and piping provided on the upper surface of the floor of the cask storage building according to the second embodiment. A jet fuel discharge structure according to Embodiment 2 of the present invention will be described with reference to FIGS. 9, 10 and 11. FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The structure on the second exhaust port 26b side will be described as an example, but the structure on the first exhaust port 26a side is the same.

  As shown in FIG. 9, the jet fuel discharge structure 30b according to the second embodiment includes a liquid collection part 32g provided on the upper surface 27S of the radiation shield 27, a liquid collection part 32f provided on the upper surface 12S of the floor 12, and a liquid collection part. It has a liquid part 32h. The liquid collection part 32f is the same as that of the first embodiment. The liquid collection part 32g and the tank 50 are connected via a liquid collection pipe 34g and pipes 36s, 36t, 36u, and 36v. The liquid collection part 32h and the tank 50 are connected via a liquid collection pipe 34h and pipes 36x and 36y.

  As shown in FIGS. 9 and 10, the liquid collection part 32 g has a liquid collection pipe 34 g embedded in the radiation shield 27. The liquid collection pipe 34g extends in the vertical direction and opens on the upper surface 27S of the radiation shield 27. That is, the liquid collection pipe 34g has an opening 40g. As shown in FIG. 10, one end of an L-shaped pipe joint 37i is attached to the lower end of the liquid collecting pipe 34g, and the other end of the L-shaped pipe joint 37i is connected to a pipe 36s. . The pipe 36 s extends in the horizontal direction toward the column 15 inside the radiation shield 27. The pipe 36s is connected to the pipe 36t via an L-shaped pipe joint 37j provided at a position in contact with the column 15.

  In the present embodiment, the pipe 36t is attached in contact with the column 15 and extends from the radiation shield 27 to the floor 12 in the vertical direction. As shown in FIG. 8, the lower end of the pipe 36t is connected to the pipe 36u via a T-shaped pipe joint 37k. The pipe 36u extends in the horizontal direction inside the floor 12, and is connected to a pipe 36v shown in FIG. 9 via an L-shaped pipe joint (not shown). The pipe 36 v extends in the vertical direction inside the floor 12 and below the floor 12, and the lower end of the pipe 36 v is connected to the tank 50.

  As shown in FIGS. 9 and 11, the liquid collection part 32 h has a liquid collection pipe 34 h embedded in the floor 12. The liquid collection pipe 34h extends in the vertical direction and opens on the upper surface 12S of the floor 12. That is, the liquid collection pipe 34h has an opening 40h. One end of an L-shaped pipe joint 37p is attached to the lower end of the liquid collecting pipe 34h, and the other end of the L-shaped pipe joint 37p is connected to a pipe 36x. The pipe 36x is connected to the pipe 36y by a pipe joint (not shown). As shown in FIG. 9, the pipe 36 y is connected to the tank 50.

  As shown in FIGS. 9 and 11, the jet fuel discharge structure 30b includes an upper surface 12S of the floor 12 below the second air supply duct 24b and a region where the cask is placed, that is, a first placement region. There is a weir 70 protruding from the floor 12 between the upper surface 12S of the floor 12 in A1 and the second placement area A2. The height of the weir 70 measured from the upper surface 12S of the floor 12 in the lower part D of the second air supply duct 24b is preferably about 0.02 to 0.5 m. The height of the weir 70 is set so as to inhibit the flow of outside air guided by the second air supply duct 24 b and not to affect the heat removal of the cask 10.

  Part of the jet fuel that has entered from at least one of the first exhaust port 26 a and the second exhaust port 26 b falls to the upper surface 27 </ b> S of the radiation shield 27. A part of the jet fuel that has reached the upper surface 27S of the radiation shield 27 is collected by the liquid collection part 32g and guided to the inside of the tank 50 by the pipes 36s, 36t, 36u, and 36v.

  Part of the jet fuel that has entered from the first air inlet 22a or the second air inlet 22b is collected by the opening 40h of the liquid collecting pipe 34h, and the inside of the tank 50 is collected by the liquid collecting pipe 34h and the pipes 36x and 36y. Led to. Moreover, since the weir 70 is provided, the jet fuel staying around the opening 40h of the liquid collection pipe 34h is unlikely to reach the first placement area A1 and the second placement area A2.

  The jet fuel discharge structure 30b according to the second embodiment includes an upper surface 12S of the floor 12 below the second air supply duct 24b, and an upper surface 12S of the floor 12 in the first placement area A1 and the second placement area A2. Since the weir 70 protruding from the floor 12 is provided between them, the jet fuel that has entered from the first air supply port 22a or the second air supply port 22b is transferred to the first mounting region A1 and the second mounting region A2. It can be suppressed to reach. Therefore, the combustion time of the jet fuel around the cask 10 is shortened, and a reduction in heat dissipation efficiency of the cask 10 and a reduction in durability of the cask 10 are suppressed.

  As mentioned above, although Embodiment 1 and Embodiment 2 were demonstrated, Embodiment 1 and Embodiment 2 are not limited by the content mentioned above. In addition, the above-described components include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the above-described components can be appropriately combined. In addition, various omissions, substitutions, and changes of the constituent elements can be made without departing from the gist of the first and second embodiments.

8 ground 10 casks 11 cask storage building 12 floor 12S upper surface 13 ceiling 14 side wall 14a first side wall 14Ia inner surface 14b second side wall 14Ib inner surface 14c third side wall 14d fourth side wall SP space 15 pillar 22 air supply port 22a first air supply port 22b 2nd air supply opening 23a 1st partition wall 23b 2nd partition wall 24 Air supply duct 24a 1st air supply duct 24b 2nd air supply duct 25 Ventilation tower 26 Exhaust port 26a 1st exhaust port 26b 2nd exhaust port 27 Radiation Shield 27S Upper surface A1 1st mounting area A2 2nd mounting area B Non-mounting area La1, La2, Lb1, Lb2 Area line Sa, Sb Radiation area AR Outside air 30a, 30b Jet fuel discharge structure 32d, 32e, 32f, 32g Liquid collection part 34f, 34g, 34h Liquid collection pipe 36, 36r, 36s, 36t, 36z, 3 6u, 36v, 36w, 36x, 36y, 55 Piping 37, 37i, 37q, 37k, 37p, 37j Fitting 38d, 38e Groove 38Bd, 38Be Bottom 38Ld, 38Le Side 40d, 40e, 40f, 40g, 40h Opening 50 Tank 60 Pump 70 Weir 80 Sensor

Claims (15)

A structure provided in a cask storage building that stores a cask and has an air supply port that introduces outside air into a space in which the cask is stored and an exhaust port that discharges outside air from the space,
Jet fuel, which is provided in at least one of a floor on which the cask is placed in a part of the area and a radiation shield provided above the floor and enters the inside of the cask storage building, A liquid collection part that collects from at least one of the upper surfaces of the radiation shield;
A tank for storing the jet fuel collected in the liquid collection unit;
A pipe that connects the liquid collection part and the tank, and guides the jet fuel collected in the liquid collection part to the tank;
Including a jet fuel discharge structure.   The jet fuel discharge structure according to claim 1, wherein the tank is installed below the floor.   The liquid collection part is a liquid collection pipe having an opening on at least one of the upper surface of the floor and the upper surface of the radiation shield, and guiding the jet fuel that has entered the opening to the pipe. The jet fuel discharge structure according to claim 1 or 2.   The jet fuel discharge structure according to claim 3, wherein the opening is provided in a portion different from a passage of a device that conveys the cask.   The said liquid collection part is a groove | channel provided in at least one among the upper surface of the said floor and the upper surface of the said radiation shield, The said piping has an opening part in at least one of the bottom face and side surface of the said groove | channel. Or the jet fuel discharge structure of Claim 2. The cask storage building has an air supply duct that extends downward from the air supply port and guides outside air from the air supply port to a space in which the cask of the cask storage building is stored,
The jet fuel according to claim 5, wherein the groove is formed by making an upper surface of the floor below the air supply duct lower than an upper surface of the floor in a region where the cask is placed. Discharge structure.   The jet fuel discharge structure according to claim 5, wherein the groove is provided in a portion different from a passage of a device that conveys the cask.   The opening is closed when the height of the liquid level of the jet fuel staying above the liquid collection part is lowered to the opening of the liquid collection pipe or the pipe. The jet fuel discharge structure according to any one of claims.   When the height of the liquid level of the jet fuel staying above the liquid collection part is reduced to the opening of the liquid collection pipe or the pipe, it is formed in at least one of the inside of the liquid collection part and the inside of the tank. The jet fuel discharge structure according to any one of claims 3 to 5, wherein an inert gas is blown. The cask storage building has an air supply duct that extends downward from the air supply port and guides outside air from the air supply port to a space in which the cask of the cask storage building is stored,
The dam protruding from the floor is provided between the upper surface of the floor below the air supply duct and the upper surface of the floor in the region where the cask is placed. The jet fuel discharge structure according to claim 1.   The jet fuel discharge structure according to any one of claims 1 to 10, further comprising a pump for pumping out the jet fuel stored in the tank from the tank.   The jet fuel discharge structure according to claim 11, wherein the pump is installed below the floor. The jet fuel discharge structure according to claim 11 or 12, wherein the pump automatically starts operation when a fire is detected by a sensor installed in a space in which the cask is stored.   The jet fuel discharge structure according to claim 11, wherein the pump automatically starts operation when it is sensed that the jet fuel stored in the tank has reached a predetermined amount. An air supply port for storing the cask and introducing outside air into a space in which the cask is stored; and an exhaust port for discharging the outside air from the space;
The jet fuel discharge structure according to any one of claims 1 to 14,
Including, cask storage building.

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