JPS6234098A - Liquid metal receptor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a container for receiving dropping droplets of liquid metal, and more specifically, the lower opening of a cylindrical body is closed with a rupture plate, so that the container is not exposed to the outside. The present invention relates to a liquid metal receiver that discharges the liquid metal dropped by destroying the rupture plate with a protrusion or the like provided therein.

[Prior art] In a nuclear couplant, core components such as fuel, control rods, and neutron sources are transferred between the reactor vessel and the external fuel storage tank, or between the fuel storage tank and various downstream equipment such as cleaning equipment. will be transferred.

These core components are moved on rails installed on the reactor operating floor by various fuel handling equipment, and lifted up and lowered by clippers at predetermined positions.

In the case of a liquid sodium-cooled fast breeder reactor, sodium is solid at room temperature and reacts violently when it comes into contact with air, so fuel and other materials are handled by remote control in a high-temperature inert gas atmosphere. Accordingly, potted fuel or bare fuel is transferred while being housed in a container called a "coffin" inside the fuel loading/unloading machine. In order to maintain an inert gas atmosphere, a door valve, which is a kind of box-shaped gate valve, is installed at the bottom of the fuel inlet/outlet machine and legal equipment. When fuel, etc. pulled up from liquid sodium is stored inside the coffin and transferred with the door valve closed to maintain airtightness, the sodium adhering to the fuel drips onto the valve body of the door valve. Since dripping sodium adversely affects the movement and sealing performance of the valve body, a receiver is provided within the valve body to receive and stop the dripping sodium.

This receiver is mounted in the door pulp using the gripper of the fuel inlet/outlet machine. Experimental results show that for a normal sized receptor, 5 to 1 liters of potted or bare fuel
When 0 bodies are transferred, the dripping sodium in the receiver becomes almost full. This spent receptor filled with sodium
It is removed from the door valve by the gripper and removed, and another new receptacle is installed.

A used receptor needs to be drained of the sodium inside. It is possible to drain the sodium inside by tilting or flipping the receptor, but the situation cannot be seen and this must be done by remote control as described above, making the mechanism complicated and extremely difficult to implement. Therefore, in the prior art, a siphon tube 12 is attached to the container 10 as shown in FIG.
The structure was such that sodium was discharged through its siphon action. Note that a protrusion provided inside the upper end of the container 10 is an engaging portion 14 that receives the claw portion of the gripper.

That is, after lifting the receiver 10 from the door pulp using a gripper and immersing it in the sodium inside the reactor vessel or the external fuel storage tank, by lifting it above the liquid level, the siphon is activated and the sodium inside is discharged. That's what I do.

[Problems to be solved by the invention] Theoretically, the siphon function should be activated by handling as described above and the liquid sodium inside the receptor should be able to be completely discharged, but the siphon function does not work properly during the test in sodium. Something happened. Since it worked well in a simulated test using water as the liquid, it is thought that the siphon function does not work well due to the compatibility of the siphon tube with sodium, which affects the flow path resistance.

By the way, the functions required for this type of liquid metal receptor are:
These include being able to store a predetermined amount of liquid metal, being able to reliably discharge the liquid metal in the receiver, and preventing the liquid metal from overflowing into the receiver housing space in the door valve. At present, there is a strong demand for the development of a liquid metal receptor that satisfies these conditions.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved liquid metal receiver that overcomes the drawbacks of the prior art as described above and fully satisfies the required conditions.

[Means for Solving the Problems] The present invention, which can achieve the above-mentioned objects, comprises a thick-walled cylindrical body having a gripper engaging portion at the upper part, and an opening formed at the lower end of the thick-walled cylindrical body. a rupture plate attached to block the dripping liquid metal.

The rupture plate must have enough strength that it will not be damaged by the weight of the liquid metal filled inside, but will be easily destroyed by the weight of the receptor and the weight of the gripper when lowered onto an external protrusion. are used.

[Operation] The operation as a liquid metal receptor is the same as the conventional one. The receptacle is mounted within the door valve by a gripper and contains liquid metal dripping from a hoisted fuel or the like. When a receiver is filled with liquid metal and is to be discharged, the receiver is lifted up using a gripper, lowered onto a destruction protrusion, and the rupture plate is applied to the protrusion to remove the receiver's own weight and the inside. The rupture plate is destroyed by applying the weight of the liquid metal contained in the rupture plate and the weight of the gripper. If the contents in the container are in a liquid state, they will immediately flow out from the broken area, and if they are in a solid state, they can be easily flowed out by heating the surrounding area.

After cleaning, the used receiver can be reused by removing the destroyed rupture plate and installing a new rupture plate.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of a liquid metal receiver according to the present invention, and FIG. 2 is a bottom view thereof. receptor 2
0 is composed of a cylindrical body 22 having a substantially cylindrical shape and a circular rupture plate 24 attached so as to close the opening at the lower end of the cylindrical body 22. The cylindrical body 22 has a thick wall structure, and has an engaging portion 26 formed on the inner circumferential side of its upper end for receiving a claw portion of a gripper, and has an inwardly directed flange portion 28 at its lower end. A stepped portion is formed on the lower peripheral edge of the inward flange portion 28, and the rupture plate 2 is provided within the stepped portion.
4 is fitted and bolts 30 are installed at several locations (two locations in this example).
Tighten with. The rupture plate 24 is attached around the periphery in a liquid-tight manner against the liquid metal dripping into the interior of the receptor 20, and its strength is such that it will not be damaged by the weight of the filled liquid metal, but the rupture plate 24 will not be damaged by the weight of the liquid metal filled with it. Receptor 2 for etc.
The material is selected to be strong enough to be easily destroyed by the weight of the gripper or the weight of the gripper.

When applying the weight of the gripper to destroy the rupture plate, the gripper 38 is lowered so that the large diameter outer peripheral edge 39 (see FIG. 3) of the gripper 38 comes into contact with the upper edge 21 of the receiver 20.

After this contact, the weight of the gripper can be applied to the receiver.

If the rupture plate 24 is installed in a state slightly higher than the lower surface of the inward flange portion 28 as in this embodiment, the rupture plate 24 will rise from the installation surface when the receiver is placed, thereby preventing damage due to unforeseen circumstances. This is preferable because it can be done.

In the above embodiment, the rupture plate 24 is attached using bolts 30, but it can also be attached by spot welding at several points as long as it can be easily removed. Further, in the above embodiment, the inward flange portion 28 is provided at the lower end of the cylindrical body 22 and the rupture plate 24 is attached to it, but the rupture plate 24 is attached directly to the lower end of the cylindrical body without the inward flange portion. It is also possible.

FIG. 3 is an explanatory diagram showing an example of draining the sodium accumulated in such a receptor.

Normally, the receiver 20 is housed in a receiver accommodating portion 34 in a valve body 32 of a door valve 30 of a fuel inlet/outlet machine. The receiver 20 is lifted and lowered by a gripper that moves up and down inside the coffin 36. The valve body 34 is horizontally movable within the box-shaped casing 40, and its operation is performed by driving a ball screw 44 with a motor 42. A protrusion 46 for destroying the rupture plate is protruded from the upper tip of the valve body 32.

The method of using such a receptor is basically the same as in the conventional case. The receptor 20 is located in the receiving portion 3 within the valve body 32.
4 to receive dripping of liquid sodium adhering to the fuel during fuel handling. Once a predetermined number of fuels have been handled, the dripping sodium fills the receiver 20. At that time, liquid sodium 4 in the receptor 20
Eject 8. For example, the fuel inlet/output machine is located at the upper part of the external fuel storage tank, the receiver 20 filled with liquid sodium 48 is grasped and lifted by the gripper 38, the motor 42 is driven, the valve body 32 is slightly retracted, and the protrusion 4G The valve body 32 is driven so that T is located below the butcher plate 24. If the gripper 38 is lowered in this state, the rupture plate 24 hits the protrusion 46, and the rupture plate 24 is destroyed by the weight of the receiver 20 and the weight of the liquid sodium 48 filled inside and the gripper 38. If the sodium in the receiver 20 is in a solid state, the door valve is further opened to lower the receiver 20 into the ex-core fuel storage tank. Ambient heat then melts the sodium, allowing it to escape through the fractured area.

The used receptor 20 from which sodium has been discharged is the gripper 3
8, it is lifted up to a position above the door pulp valve body 32 at the bottom of the fuel inlet/outlet machine. Thereafter, this valve body 32 is closed.

After that, this fuel loading/unloading machine that stored the spent receptor 20 moved from the upper part of the ex-core fuel storage tank, which was the station where sodium discharge work had been performed, to the next station, the receptor storage area. Moved to the upper station. This movement is performed by a moving type in which the entire fuel inlet/output machine runs on rails.

At this moving position, the valve body 32 moves back again (opens the valve).
be done. The used receiver 20 is then stored in the receiver storage section by lowering and separating the gripper. Next, a new receiver prepared in advance in the receiver housing is gripped and lifted by the gripper and raised to a position above the door valve body 32. The valve body 32 is then advanced (valve closed), and the new receiver is separated from the gripper and the receptacle 3 in the valve body 32 is moved forward (valve closed).
It can be kept within 4. In this way, the exchange of receptors takes place. After this, the fuel injector can again handle fuel, and the new receiver can receive the sodium drips from the fuel assembly.

The above is a case where the receptor storage section stores both used and new receptors together, but there are also cases where the used receptor storage section and the new receptor storage section are stored separately. The fuel loading/unloading machine may replace the receptor by sequentially moving between the upper position station of the used receptor storage part and the upper position station of the new receptor storage part. The receptor 20 from which sodium has been discharged can be reused by cleaning it, removing the destroyed rupture plate, and attaching a new rupture plate.

FIG. 4 is an explanatory diagram showing an example in which a slide plate for destroying the rupture plate is provided in the door valve, and the structure of the slide plate is shown in FIG. Since the basic structure of the door valve is almost the same as that shown in FIG. 3, corresponding parts are denoted by the same reference numerals and a description thereof will be omitted.

The difference between this embodiment and the embodiment shown in Fig. 3 above is that the projection for destroying the rupture plate is not directly attached to the valve body of the door valve, but is mounted on a slide that can move horizontally independently. This is because it is attached to the board. This slide plate 50 has wheels 52 on both sides and can freely move horizontally on rails (not shown) provided inside the box-shaped casing 40. A large through hole 54 is formed in the slide plate 50, and a protrusion 58 for destroying the rupture plate is provided at the center of the through hole 54, supported by a crosspiece 56. An electromagnetic solenoid 60 is provided on the valve body 32, and an operating piece 62 thereof is configured to be freely retractable from the upper surface of the valve body. In addition, a hook 64 is provided on the lower surface of the slide plate 50 to correspond to this.

First, as shown in No. 418, only the valve body 32 is moved forward with the slide plate 50 left in place to close the valve, and the sodium dripping from the pulled up fuel 66 is received by the receiver 20. When such an operation is performed for a predetermined number of fuels, the inside of the receiver 20 is filled with the dropped sodium. When such a state is reached, the receiver 20 is lifted up by the gripper 3B. After retracting the valve body 32, the electromagnetic solenoid 60 is activated to cause the operating piece 62 to protrude.
4 and 3 (see B in the same figure). Then, the valve body 32 integrated with the slide plate 50 is moved forward as shown in FIG.

Thereafter, the electromagnetic solenoid 60 is activated to retract the actuating piece 62, and only the valve body 32 is retracted while leaving the slide plate 50. In this way, the projection 58 for destroying the rupture plate will be located just below the rupture plate 24 of the receiver 20 being lifted. If the gripper 38 is lowered in this state, the rupture plate 24 will hit the protrusion, and the rupture plate 24 will be destroyed by the weight of the receptor 20, the weight of the sodium contained therein, and the weight of the gripper 38, and the liquid sodium will be transferred to the slide plate 50. through hole 54
It will be discharged into the external fuel storage tank below (see the same diagram).

Destroy the rupture plate 24 and remove the liquid sodium inside.
The JI-out receiver 20 is lifted up by the gripper 38. Next, as shown in the same figure, the valve body 3 of the door valve
2 is moved forward, the electromagnetic solenoid 60 is activated, and the operating piece 62 is projected and engaged with the hook 64. In this state, the valve body 32 is moved backward together with the slide plate 50, and the electromagnetic solenoid 60 is activated to retract the actuating piece 62, thereby moving only the valve body 32 forward. Next, the fuel inlet/output device is moved to the upper position station of the receiver storage section, the valve body 32 is moved back (valve open) at this position, the used receiver 20 held by the gripper 38 is hung and separated, and the receiver is removed. A new receiver 20 is attached to the container accommodating portion 34 using the gripper 38 (see F in the same figure). After that, fuel can be handled again.

With this configuration, the slide plate 50 can be moved by the drive mechanism of the valve body, so the structure of the door pulp does not become so complicated.

Such a sliding rupture plate breaking device can be used whether the sodium in the receptor is molten or solidified. If the rupture plate is solidified, the rupture plate may be broken, then lowered using a gripper, inserted into the in-core fuel storage tank, and melted and flowed out using the heat.

The location where the protrusion for destroying the rupture plate is provided is not limited to the valve body of the door valve, but may be provided at any appropriate location within the movable range of the fuel intake/exit device, such as the location of the gripper/adapter exchange device. Further, the location is not limited to an inert gas atmosphere, and may be located at an appropriate location within the sodium fuel storage tank. For example, the ex-core fuel storage tank of the fast breeder reactor prototype reactor "Monju" currently under construction uses a rotating rank system, so it can be stored at a suitable location on the circumference, avoiding the racks that store fuel directly under the floor door valve. It is also possible to drain the sodium in the receptor by attaching a protrusion 68 as shown in FIG. 6 to the location and destroying the rupture plate in the sodium.

[Effects of the Invention] As described above, the present invention has a configuration in which a rupture plate is attached to the lower end of a cylindrical body that can be handled with a gripper.
The liquid metal accumulated in the container can be easily and reliably discharged by destroying the rupture plate on the bottom surface. Therefore, the present invention does not require a complicated siphon mechanism as in the past, making it easier to manufacture a liquid metal receptor, allowing liquid metal to be easily discharged by remote control, and cleaning the container after use. It has the effect of

Since the rupture plate is replaceable, the container can be reused.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the liquid metal receiver according to the present invention, FIG. 2 is a bottom view thereof, FIG. 3 is an explanatory diagram showing an example of the liquid metal receiver in use, and FIG. 4 is a process explanatory drawing showing another example of the liquid metal receptor in use, Fig. 5 is an explanatory drawing showing an example of the slide plate in Fig. 4, and Fig. 6 is another example of the projection for temporary rupture destruction. The perspective view shown in FIG. 7 is an explanatory diagram showing an example of the prior art. 20... Liquid metal receptor, 22... Cylindrical body, 24.
...Rupture plate, 26...Gripper engaging portion, 28.
...Inward flange part, 30...bolts. Patent applicant: Power Reactor and Nuclear Fuel Development Corporation Representative, Shigeru Miyoshi Hitoshi Figure 1 Figure 2

Claims (1)

[Claims] 1. A liquid metal receiver consisting of a thick-walled cylindrical body having a gripper engaging portion at the top and a rupture plate attached to the bottom end of the thick-walled cylindrical body so as to close an opening formed therein.