JPS5831558B2 - Adapter for collecting the dripping sodium tray attached to the reactor fuel handling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is a method of adjusting the dripping sodium saucer attached to the door valve of a fuel handling machine for a fast breeder reactor using liquid metal Sl-IJium as the primary coolant to the operating position by remote control of a gripper. The present invention relates to an improvement of a saucer collection adapter used when collecting from a saucer.

The spent fuel in the liquid metal cooled fast breeder reactor is taken out of the reactor and transferred to the spent fuel storage facility using a fuel handling machine.

Such a fuel handling machine will be explained with reference to FIG.

In the figure, 10 is a nuclear reactor, 11 is a reactor core, 12 is liquid metal sodium as a primary coolant, 13 is an upper plug of the reactor vessel, and 14 is a door valve on the reactor side that is connected to the fuel exchange hole 15 of the plug. It is.

On the other hand, the fuel handling machine 20 is equipped with a door valve 23 at the lower end of a fuel storage cylinder 22 mounted on a traveling truck 21, and grips fuel by lifting and lowering a gripper 24 installed inside the fuel storage cylinder 22. It is configured to be lifted and lowered.

Further, the door valve 23 is closed to shut off the fuel storage cylinder from the atmosphere except when connected to the reactor vessel or fuel storage equipment.

By the way, when spent fuel is suspended from inside the reactor into the fuel storage cylinder 22, the sodium adhering to the fuel will drip, so if this sodium is left to drip, it will scatter onto the door valve and solidify. It will accumulate and cause the door valve to malfunction.

As a preventive measure, conventionally, a dripping sodium receiving tray (hereinafter simply referred to as a "receiving tray") indicated by the reference numeral 30 is attached to the upper surface of the valve body of the door valve 23.

When a certain amount of sodium dropped during fuel handling has accumulated in the saucer 30, the saucer 30 is removed from the door valve 23 and transferred to a cleaning facility, where the sodium is washed away.

After cleaning, it is attached to the door valve 23 again and used.

In this case, the attachment/detachment and transfer of the saucer 30 are all carried out by the fuel handling machine 20.
This is done by remote control using the gripper 24.

Although an empty saucer can be grasped as it is with the gripper 24, it is difficult to directly grasp a saucer that is almost completely filled with solidified and deposited sodium with the gripper 24. When collecting the tray 30, a special collecting adapter designated as 40 is used, which is gripped by the gripper 24 to collect the tray 30.

Next, the sequence of the saucer recovery operation performed using the saucer recovery adapter 40 (hereinafter simply referred to as "adapter") will be described in more detail with reference to FIG.

First, the adapter 40 is placed on the furnace-side door valve 14 or the door valve in the saucer cleaning equipment and placed on standby, the door valve 23 is opened with the fuel handling machine 20 connected, and the adapter 40 in the standby position is grabbed with the gripper 24 and temporarily lifted upward. hang it to

Next, the door valve 23 is closed, the gripper 24 is lowered, the adapter 40 grips the saucer 30, and the gripper 24 is lifted up again.

Next, the fuel handling machine 20 is connected to the saucer cleaning equipment, each door valve is opened, the saucer 30 is suspended into the cleaning equipment together with the adapter 40, and the gripper 24 and the adapter 40 are separated here.

Further, the adapter 40 is taken out from the cleaning equipment after cleaning the tray 30, and is removed from the tray 30 by an operator by manual operation.

In addition, the saucer 30 after cleaning is attached to the door valve 23 of the fuel handling machine.
To attach the saucer 30 to a
0 is hung onto the valve body of the door valve 23, and the gripper 24 is then separated from the saucer 30.

As a saucer collection adapter handled as above,
In order to ensure the collection of trays, the following requirements must be fully met:

First, when the adapter 40 placed in a free and independent position is grabbed by the gripper 24, the adapter does not fall over even if some eccentric load is applied to the adapter by the gripper, and the stability of the free-standing posture is good.

To ensure that claw action when grasping a saucer is not hindered by sodium deposited in the saucer.

Furthermore, after gripping the saucer, the gripping state is reliably maintained.

By the way, a conventional adapter for collecting a saucer is constructed as shown in FIGS. 2 and 4.

FIG. 2 shows a state in which the adapter 40 is gripping the saucer 30 filled with dripping l-IJum Na, and FIG. 4 shows the adapter 40 in an independent standby position when gripped by a gripper.

First, in FIG. 2, the saucer 30 is equipped with a handling head 31 that protrudes inward from the periphery of its opening.

This handling head 31 includes a gripper of a fuel handling machine,
A claw on the adapter 40, which will be described later, engages.

On the other hand, the adapter 40 includes an adapter body 42 equipped with a gripper hat ring head 41 on the top, and
A claw 44 protrudes downward from the lower surface and is swingably supported around a horizontal support pin 43 so that the claw can open and close with respect to the handling head 31 of the saucer 30. The state in which the claw part protrudes outward toward the handling head 31 is defined as "open," and the state in which the claw part retreats inward is defined as "closed.") The claw 44 and adapter constantly urge the iron water 44 to open. A tension spring 45 stretched between the central boss of the main body 42
, a release cam 46 disposed so as to come into contact with a stepped portion formed on the inner back surface of the claw 44 from below, and a release rod 4γ for manually pulling the release cam 46 upward.

Note that a plurality of pawls 44 (for example, three pawls) are arranged on the circumference.

The operation of handling the adapter 40 and the operation of grasping the saucer are as follows.

First, the adapter 4 is placed in a standby position in a self-supporting position as shown in Figure 4.
0, the gripper of the fuel handling machine descends from above and grips the handling head 41 of the adapter 40.

After that, when the adapter 40 is suspended onto the saucer 30, the tapered surface 48 of the tip portion of the claw 44 first touches the saucer 30.
Then, the pawl 44 slides downward along the handling head 31 while being biased by the spring 45 and engages with the handling head.

The gripping state of the saucer 30 is maintained by the biasing force of the spring 45.

To remove the adapter 40 from the saucer after cleaning the saucer 30,
By manually pulling the release rod 41 upward, the claw 44 closes against the spring 45 and is separated from the saucer 30.

However, the above-mentioned conventional adapter has the following drawbacks.

First, when the adapter 40, which is standing by and standing by in a fixed position, is grabbed by the gripper of the fuel handling machine, the center of the gripper and the center of the adapter 40 do not always match exactly;
Some eccentricity often occurs.

In this case, an eccentric load of the gripper is applied to the adapter 40 in FIG. 4 as indicated by arrow A.

Although the pawl 44 of the adapter 40 receives a biasing force in the opening direction from the spring 45, it can swing in the closing direction, so when the above-mentioned eccentric load is applied, the adapter 40 will be deformed as shown by the chain line. 44 is tilted and buckled, and the entire body moves outward as shown by arrow B.
There is a risk of tipping in one direction and falling.

Moreover, since the adapter is already exposed to the radioactive atmosphere inside the fuel storage cylinder of the fuel handling machine, the worker cannot directly touch it, and once the adapter 40 falls over, it is extremely troublesome to return it to its original position.

Furthermore, when grasping the saucer 30, in order to slide and push the openable claw 44 onto the inner peripheral surface of the handling head 31 of the saucer to engage it, some eccentricity between the adapter 40 and the saucer 30 must be taken into account. Therefore, the length of the tapered surface 48 of the claw 44, that is, the length of the claw 44, must be set sufficiently long in advance.

This not only increases the overall height of the adapter 40 and reduces the stability of its self-supporting posture, but also increases the amount of sodium chloride when the claw 44 is inserted into the saucer 30 filled with sodium Na as shown in If the amount of accumulation is large, the tip of the claw 44 may hit the solidified and deposited sodium and be blocked, making it impossible to grip it.

In such a situation, it becomes impossible to collect the saucer 30 by normal means, and the saucer recovery operation is significantly hindered.

In addition, if the spring function of the biasing spring 45 deteriorates, the operation becomes extremely unstable.

This invention has been made in view of the above points, and aims to eliminate the drawbacks of conventional saucer collection adapters and to obtain a highly reliable saucer collection adapter that fully satisfies each of the above-mentioned requirements. .

In order to achieve such an object, according to the present invention, the claws of the adapter are always closed in a standby state so as to retreat inwardly by the claw closing and holding mechanism, and the claws are closed only when the adapter is coupled to the saucer. is opened, and after the amount of water is opened, the claw is locked in the open position by the claw closing and holding mechanism, so that the saucer gripping state can be maintained reliably.

Next, the configuration and operation of the adapter according to the present invention will be described in detail based on the illustrated embodiments.

In FIGS. 3 and 5, the adapter 40 is roughly divided into an adapter body 52 equipped with a handling head 51;
It is composed of a combination of a plurality of pawls 54 that protrude downward from the adapter body 52 and are arranged on the circumference, a pawl closing and holding mechanism 55, and a pawl closing and holding mechanism 56.

Of these, the adapter body 52 is almost the same as the conventional one.

On the other hand, the pawl 54 is made as a single-shaped bifurcated lever structure that is supported pivotally on the support pin 53, and its lower side serves as a pawl portion 541 that engages with the handling head 31 of the saucer 30 from the inner circumferential side. The remaining upper side portion is an actuator portion 542 for use between the claws that protrudes outward.

The claw closing and holding mechanism 55 installed opposite the claw 54 includes a case 551 attached to the adapter body 52, a compression spring 552 housed in the case, a ball seat 553, and a ball seat 55.
3 and a ball 554 inserted between the top surface of the actuator portion 542 of the pawl 54, and as shown in FIG. and press the claw 54 onto the support pin 5.
3 in the counterclockwise direction as shown by arrow C to close the claw portion 541.

Furthermore, the claw closing and holding mechanism 56 includes a case 561 attached to the center of the adapter body 52, an inverted cone-shaped actuating body 562 housed within the case, and a compression spring 563 that presses the actuating body 562 downward. , a release iron 564 for manually pulling the actuating body 562 upward against the spring 563, and an intermediary between the outer circumferential surface of the actuating body 562 and the back surface of each of the plurality of claws 54 arranged on the circumference. It is constructed as a ball latch mechanism consisting of a combination with an inserted ball 565.

Note that a ball socket stepped portion 543 is formed for each claw at the upper part of the back surface of the claw 54 facing the ball 565.

Therefore, when the release iron 564 is manually pulled upward, the pawl 54 is closed by the spring bias of the pawl closing and holding mechanism 55 described above, and the ball 565 moves backward inward along the conical surface of the actuating body, causing the pawl 54 to close. Since the claw 54 is removed from the ball socket stepped portion 543 of the release rod 564, the claw 54 remains closed even if the release rod 564 is released.

Also, as shown in FIG. 3, once the claw 54 is opened, the ball 565
is biased by a spring 563 via an actuating body 562, and is pushed outward and fitted into the ball socket stepped portion 543.

In this state, the pawl 54 is locked in the open position and the valve remains open unless the release rod 564 is pulled up again.

In addition, in the stand-alone posture of the adapter 40 shown in FIG. 5, the tip landing point P of the claw portion 541 that lands on the floor surface is aligned with the perpendicular line passing through the support shaft 53, or is positioned outside of the perpendicular line. It is determined.

Furthermore, the position of the ball 565 in the claw closing and holding mechanism 56 is located almost right beside the spindle 53 of the claw 54, and the ball 565
65 so that the claw 54 is not subjected to unnecessary rotational moment due to the force applied to the claw 54.

Next, a saucer collection operation using the adapter configured as described above will be described.

The adapter 40 pulls up the release iron 564 in advance, and the claw 54
Let it stand on its own as shown in Figure 5 while keeping it closed.
It is grabbed by the gripper of the fuel handling machine.

In this case, as described in the description of the conventional adapter, even if a slight eccentric load is applied from the gripper, the claws 54 will remain in the closed position and will not tilt inward and buckle, resulting in a self-supporting posture. It remains stable and there is no risk of it falling over.

Now, when the gripper grips the adapter 40 and then suspends it over the saucer 30 attached to the door valve as shown in FIG. Just go through it.

Subsequently, the actuator portion 542 of the claw 54 hits the top surface of the handling head 31, and the weight of the gripper is further applied to the adapter 40, so that the claw 54 rotates clockwise around the support shaft 53 and closes. 541 engages the handling head 31 and grips the saucer 30.

At the same time, the claw closing and holding mechanism 56 operates, and the ball 565 moves to the claw 5.
4 and locks the pawl 54 in the open state.

Furthermore, unlike conventional adapters, the claws 54 are inserted in a closed state at the stage of coupling with the saucer 40, so there is no need for the long tapered surfaces of the claws as in the conventional adapters, and therefore the length of the claws 54 can be short.

This not only reduces the height of the entire adapter 40 in the standby position and increases the stability of the stand-alone position, but also reduces the possibility that the inter-claw movement will be inhibited by the sodium Na deposited in the saucer 30.

As is clear from the above description, according to the present invention, the drawbacks of the conventional adapter are solved, and the stability of the self-supporting posture when gripped with a gripper is improved, and there is no possibility of failure to grasp the saucer, and there is no possibility of grasping the saucer. It is possible to provide an adapter for collecting a dripping sodium tray that has excellent functionality and high reliability, such as being able to reliably hold the gripped state after the dripping.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the overall configuration of a fuel handling machine equipped with a dripping sodium tray, FIGS. 2 and 3 are cross-sectional views of the configuration of the conventional adapter and the adapter according to the embodiment of the present invention showing the tray gripping state, respectively. FIG. , and FIG. 5 are stand-alone posture diagrams showing the standby state of the adapters shown in FIGS. 2 and 3, respectively. 20...Fuel handling machine, 23...Door valve, 24...Gripper, 30...Dripping l-IJ um saucer, 31...・Saucer handling head, 40...Saucer collection adapter,
51... Handling head of adapter, 52
...Adapter body, 54 ...Claw, 54
1...Claw part, 542...Actuator part, 543...Ball socket step part, 55...
...Claw closing holding mechanism, 552...Biasing spring,
554...Ball, 56...Claw closing holding mechanism, 562...Operating body, 563...
Biasing spring, 564...Manual pull-up release rond, 56590900. Ball, Na...Deposited sodium accumulated in the saucer.

Claims (1)

[Scope of Claims] 1. An adapter for collecting a saucer used when collecting a saucer for collecting sodium dripping from fuel during fuel handling from a mounting point by remote control using a gripper of a fuel handling machine, the adapter having a gripper on the top. When the adapter body equipped with a handling head, the claw part that engages with the handling head of the saucer by opening the lower side outward, and the upper side hit the top surface of the handling head of the saucer and are pushed up. A bifurcated lever structure is provided with an actuator between the claws that is operated to open the claws, and the claws protrude downward from the adapter body so that the claws can be opened and closed. , a claw-closing holding mechanism that always urges the iron water in the closing direction, and a claw-closing holding mechanism that can be manually released and operates as if locking the claw in the open position when the claw is opened. A collecting adapter for a dripping sodium tray attached to a nuclear reactor fuel handling machine. 2. In the collection adapter according to claim 1, the claw closing and holding mechanism includes a ball that comes into contact with the upper surface of the actuator portion of the claw, and an urging spring that presses and urges the ball in the direction in which the claw closes. An adapter for collecting a dripping sodium saucer attached to a nuclear reactor fuel handling machine, characterized in that the adapter comprises: 3. The collection adapter according to claim 1, wherein the claw closing and holding mechanism is located at the center of the adapter body and has an inverted cone-shaped actuating body that can be manually pulled up, and the actuating body is constantly operated. A ball latch equipped with a biasing spring that presses downward and a ball inserted for each pawl between the outer circumferential surface of the operating body and the inner circumferential back surface of the pawl where the ball socket stepped portion is formed. An adapter for collecting a dripping sodium saucer attached to a nuclear reactor fuel handling machine, characterized in that it is configured as a mechanism.