JPS60180677A - End stopper for fuel element welding device - Google Patents

Abstract

PURPOSE:To make peripheral welding, cooling and pressure welding in end stopper welding of fuel element continuously by making a cooling chamber of He gas atmosphere communicate with a peripheral welding section and pressure welding section of a welding chamber through outlet and inlet ports respectively. CONSTITUTION:Fuel element H preliminarily cooled in an air lock chamber is led from an inlet port 26 to a secondary cooling chamber 6 of He gas atmosphere and advanced to a position D in a barrel 25. In the meantime, it is cooled to a specified temperature. Then it is sent from outlet and inlet ports 28 to the peripheal welding section 34 of a welding chamber 33, and after peripheral end stopper welding, pulled back to the cooling chamber 6. The fuel element (h) advances to the position of the second exit port 29 while being cooled by rotation of the barrel 25, and sent to the pressure welding section of the welding chamber 33 and pressure-welded. Then, it is returned to the cooling chamber 6 again, and after cooling, sent to the air lock chamber 51 for discharge. Tact time can be shortened and its throughput can be increased without strain by this device.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a fuel element end plug welding device that can be used in the manufacturing process of nuclear reactor fuel elements.

(b) According to the prior art (a fuel element for a sub-furnace is manufactured as shown in Fig. 1. First, as shown in Fig. 1 a), a stainless steel pipe is airtightly fitted with an end plug a at one end. Pellets c such as uranium oxide are filled into the chamber b.

Thereafter, as shown in FIG. 1, a breathable temporary end stopper d is removably attached to the other end of the stainless steel pipe b. Then, in this state, degassing and He replacement processing as described below are performed, and then the temporary end plug is removed and a spring e and a full-fledged end plug f are installed, and this end plug f and the stainless steel Airtightly extend and connect joint g with pipe b. At the same time, the welding point l-k is melted and closed to complete the pressure welding. Note that pressure welding here refers to inserting the end plug of the fuel element that has undergone the circular welding into a pressurizing chamber, introducing high-pressure He gas into the pressurizing chamber, and discharging the He gas. This is an operation in which fuel is filled into the fuel element through a small hole m provided in the end plug f, and then the open end k of the small hole m is melted and closed.

By the way, such welding processing has conventionally been performed using a patch type device. That is, in the conventional device, 20 to 30 half-finished fuel elements h' as shown in FIG.
It has a single chamber that can be held by a main barrel and a welding chamber adjacent to this chamber, which includes a circular weld and a pressurized weld along a single thread. A welded part is provided. First, the inside of the chamber is evacuated and then heated for a required period of time to perform degassing.

That is, the moisture contained in the pellet C and the stainless steel pipe b is removed. When the degassing step is completed, He gas is introduced into this chamber to perform He replacement and cooling at the same time. After the fuel elements in the chamber have been subjected to degassing and He replacement treatment in this way, the fuel elements are pulled out from the chamber one by one, and the shaft ends of the fuel elements are welded around the welding chamber. Insert it all the way to the top. After replacing the temporary end plug and the wooden end frame in this welding chamber, circular welding is performed and the temporary end plug is pulled back into the chamber. In this manner, after completing a full number of welds, the fuel element is retained within the chamber until its end plug weld has cooled to a suitable temperature. Then, the fuel elements are again pulled out one by one from the chamber along the same wires as described above and pressure welded. That is, the end plugs of each of the fuel elements are passed through the circumferential welding part of the welding chamber and inserted into the pressure welding part beyond that, and the aforementioned pressure welding is applied to the end plugs. Note that the reason why the fuel element is once returned to the chamber to cool it after round welding is because if pressure welding is performed immediately after round welding, the heat remaining in the end plug of the fuel element will damage the sealing member of the pressure chamber. This is because it will deteriorate or be damaged.

Although it is possible to perform welding on the end plug of the fuel element in this manner, such conventional welding is of the Nohetch type and is therefore inefficient. In particular, with such a configuration, when circular welding is being performed, the pressure welding section stops its function, and conversely, when pressure welding is disabled, circular welding cannot be performed. Therefore, there is a problem in that it is difficult to increase the processing time without increasing the number of devices installed.

(c) Purpose The present invention was made with attention to such circumstances,
We have developed an end plug welding device for fuel elements that can perform the processing steps of lap welding, cooling, and pressure welding sequentially and continuously, shortening takt time and increasing processing performance effortlessly and effectively. The purpose is to provide.

(D) Structure In order to achieve the above object, the present invention provides an end plug welding device for a fuel element with an internal He gas atmosphere, artificial ports for introducing the fuel element into the end wall thereof, and artificial ports at mutually different positions. a cooling chamber having four inlet/outlet ports provided in the cooling chamber and an outlet port I for leading out the fuel element; a barrel for receiving the fuel element sent to the cooling chamber and sequentially moving it in 17 rows to a position facing each of the ports; and a circumferential welded portion located adjacent to the cooling chamber and corresponding to the first lead-in/out port; a welding chamber having a pressurized welding portion at a portion corresponding to the second lead-out man port, and the fuel element held in the barrel is connected to the first lead-out man port and the second lead-out man port. The fuel element is temporarily drawn out through the corresponding boat to the circumferential welding part and the pressurized welding part to perform a welding process when the fuel element reaches the first lead-in/out port and the second lead-out port. It is characterized in that the distance from the port is set to a value that allows the end plug portion of the fuel element heated by circular welding to be cooled to an appropriate temperature before reaching the pressure welding portion.

(e) Examples Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 2, there is a filling device 1, a lateral movement device 2 for receiving, an airlock chamber 3 for receiving, a degassing chamber 4, an airlock chamber 5 that also serves as a primary cooling chamber, and a 2-airlock chamber for He replacement. A secondary cooling chamber 6 is provided in series.

The filling device 1 loads a spring i, a spacer j, and a pellet C into a stainless steel pipe b which has an end plug a airtightly attached to one end thereof, and detachably attaches a temporary end plug d to the other end of the stainless steel pipe b. It is for the purpose of
The semi-finished fuel element h' manufactured in this manner is sent out along the first surface line A in the axial direction. and.

A gate valve 7 is interposed between the filling device 1 and the receiving lateral movement device 2. In addition, the receiving lateral movement device 2 is the first one! It is configured to move the fuel element h' fed in at mA in parallel to the second line B and send it out along the second line B. A second gate valve 8 is provided between the lateral movement device 2 and the first efficiency chamber 3. The receiving airlock chamber 3 has a closed structure connected to an exhaust device 9, and the interior thereof can be switched between an atmospheric atmosphere and a vacuum atmosphere. A third gate valve 11 is interposed between the aerodynamic chamber 3 and the degassing chamber 4. Degassing chamber 4
is formed in a sealed container 13 connected to the exhaust device 12, and houses a barrel 14 for holding a fuel element therein.

The barrel 14 is made by connecting a plurality of disks 14a with their axes aligned, and #i number of holding holes 14b are bored at equal pitches in the circumferential direction near the periphery of each disk 14a. It is.

Then, the fuel element h'
are held one by one and rotated intermittently by l pitches.

Incidentally, an incoming boat 15 corresponding to the second line B and an outgoing port 16 corresponding to a third line C parallel to the second line B are bored in the end wall of the sealed container 13. It is. Then, each time the acid barrel 14 completes its intermittent rotation, the holding hole 14b is made to face the inlet port 15 and the outlet port 16. Further, within this sealed container 13, a heater 17 is provided for heating the fuel element h° held in the barrel 14 and rotated.
is arranged. A gate valve 20 is interposed between the outlet port 16 of this degassing chamber 4 and the second aerodynamic chamber 5 indicated at 1111. The second aerodynamic chamber 5 is
Exhaust device 18 and He gas supply device i! : It has a sealed structure with a
It is possible to switch between the e-gas atmosphere and the e-gas atmosphere.

A gate valve 21 is interposed between the aerodynamic chamber 5 and the secondary cooling chamber 6.

The secondary cooling chamber 6 includes an exhaust device 22 and a He gas supply device 2.
It is formed in a sealed container 24 connected to the above-mentioned barrel 14, and houses a barrel 25 for holding a combustion element having the same structure as the barrel 14. Note that the sealed container 24
On one end wall of.

The entrance boat 26 corresponding to the third line C and this third
Exit that corresponds to the 5th lane E parallel to the line C [J boat 27
is bored, and the other end wall is provided with a first lead-out boat 28 that coincides with a fourth passageway parallel to the third passageway C.
A second lead-out port 29 corresponding to the fifth line E is bored.

The inside of this second cooling chamber 6 is always maintained in a He gas atmosphere. That is, the second cooling chamber 6 is sufficiently evacuated before steady operation. After the steady operation for He gas replacement is started, this He gas atmosphere is always maintained as is, except when the oxygen and moisture conditions deteriorate. Therefore, the exhaust device 22 is not used during steady operation. Note that in this secondary cooling chamber 6, it is possible that the temperature of He gas gradually increases by -L.
The temperature inside the chamber is controlled by circulating e-gas and forced cooling using a cooler (not shown).

In addition, the first and second lead-in/output boats 2 of this secondary cooling chamber 6
8.29 to the welding chamber 33 via the gate valve 31.32
It communicates with The welding chamber 33 has a sealed structure, and the interior thereof is maintained in a He gas atmosphere. Therefore, like the secondary cooling chamber 6 described above, it is sufficiently evacuated before steady operation and then filled with He gas. Thereafter, this atmosphere is maintained at all times except when the oxygen and moisture conditions 71 have deteriorated, and no exhaust is performed during steady operation. and,
A circumferential welding section 34 is provided at a portion of the welding chamber 33 corresponding to the fourth line E, and a pressure welding section 35 is provided at a portion corresponding to the fifth line E.

The circumferential welding part 34 includes a main chuck 36 that grips the stainless steel pipe b of the fuel element h' and rotates it around its axis, and a main chuck 36 that grips the end plug d (or f) of the fuel element h' (or h). Sub-chuck 37 that rotates around the axis
and a welding torch 38 with a nozzle facing the fuel element insertion passage between both chucks 36 and 37. The sub-chuck 37 can also move forward and backward in the axial direction of the fuel element. On the other hand, the pressure welding part 35 includes a chuck 39 that grips the stainless steel pipe 5 portion of the fuel element and rotates the fuel element to a fixed position around the axis and fixes the fuel element, and a A pressurizing chamber 41 that airtightly holds the end plug mounting portion of the fuel element is inserted into the pressurizing chamber 41, and a welding hole 42 having a nozzle facing the outer periphery of the end plug f of the fuel element inserted into the pressurizing chamber 41 is provided. It is. The pressurizing chamber 41 can move forward and backward in the axial direction of the fuel element.

Then, the separation distance between the first outlet port 28 and the second outlet port 29 is adjusted by circular welding until the end plug of the heated fuel element reaches the pressure welding part 35. The temperature is set at a temperature that can be cooled to a temperature that does not adversely affect the sealing member provided in the shaft sealing portion 41a of the pressurizing chamber 41.

Note that a crane 44 for suspending a multi-function/stand 43 and an equipment pallet 45 is provided in this welding room 33. In addition, an equipment insertion chamber 46 is provided in this welding chamber 33.
Installation, please. This equipment insertion chamber 46 is for loading and unloading an equipment pallet 45 loaded with equipment such as end plugs into and out of the welding chamber 33 which is in steady operation in a He gas atmosphere. It has an inner door 48 communicating with.

Further, the fuel element sent out in the axial direction from the outlet boat 27 of the secondary cooling chamber 6 through the gate valve 49 is disposed of in the exhaust air chamber 51. Air delivery chamber 5
2 and a lateral transfer chamber 53 for discharging to a decontamination device 54. The exhaust air chamber 51 is
It has a sealed structure connected to an exhaust device 55 and a He gas supply device R56, and the interior can be switched between a He gas atmosphere and a vacuum atmosphere. A gate valve 57 is interposed between this discharge airlock chamber 51 and the discharge airlock chamber 52. The dispensing air chamber 52 has a sealed structure connected to an exhaust device 58 and a N2 gas supply device 59, and has an airtight structure in which the interior can be switched between a vacuum atmosphere and an atmospheric atmosphere.
I'm +l'r-.

A gate valve 61t is provided between the dispensing airlock chamber 52 and the lateral movement device 53. The lateral movement device 53 is configured to move the fuel element fed along the :tS5 line E in parallel to the sixth line F, and send it out along the flS6 line F. and,
A gate valve 62 is provided between this lateral movement device 53 and the decontamination device rL54.

The filling device 1, the receiving lateral movement device 2, the receiving airlock chamber 3, the degassing chamber 4, the primary cooling airlock chamber 5, the secondary cooling chamber 6. Passages 63 and 64 that communicate the secondary cooling chamber 6 and the welding chamber 33, and an air discharge chamber 51
．． A fuel element is provided in the dispensing airlock chamber 52 and the dispensing lateral movement VJ device 53 by a pinch roller and a drive roller.

A transfer mechanism (not shown) is provided for holding h' and sending or drawing it in the axial direction.

Next, the operation of this embodiment will be explained.

After filling pellets c, semi-finished fuel elements h° equipped with temporary end plugs d are sent out from the filling device 1 along the first line A one by one every 1 takt, and are sequentially transferred to the receiving lateral movement device 2. Introduce. Then, this fuel element h° is moved in W rows to the second passage B by the lateral movement device 2, and when the gate valve 8 is opened, the fuel element h' is sent out in the axial direction to an air lock for receiving atmospheric atmosphere. Introduced into room 3. Thereafter, the gate valve 8 is closed and the exhaust device 9 is operated to evacuate the air lock chamber 3. After the inside of this aerodynamic chamber 3 reaches a vacuum atmosphere similar to that inside the degassing chamber 4, the gate valve 11 is opened and the fuel element h in the aerodynamic chamber 3 is introduced into the degassing chamber 4. do. At this time, the transfer mechanism of the aerodynamic chamber 3 and the degassing chamber 4
The fuel element h' is retained in the barrel 14 of the degassing chamber 4 in cooperation with a transfer mechanism. The barrel 14 has one fuel element per 1 takt time.

Hold and rotate intermittently in the direction of the arrow. As a result, the fuel element h' moves within the degassing chamber 4 while being heated and degassed for about 3 hours, and reaches the discharge position corresponding to the third passage C. Then, the fuel element h reaches the discharge position
' are sequentially sent out in the axial direction along the third wire C.

That is, when the fuel element h' faces the outlet port 16, the gate valve 20 is opened and the fuel element h' is transferred from the degassing chamber 4 to the aerodynamic chamber 5. At this time, the inside of the aerodynamic chamber 5 is kept in a vacuum atmosphere similar to the inside of the +i:j degassing chamber 4, and the fuel element h
After transferring the He
Switch to gas atmosphere. As a result, the fuel element h in the airlock chamber 5 is preliminarily cooled. Then,
The gate valve 21 is opened and the fuel element h in the airlock chamber 5 is introduced into the secondary cooling chamber 6. At this time, the fuel element is transferred by cooperation between the transfer mechanism of the aerodynamic chamber 5 and the transfer mechanism of the secondary cooling chamber 6.

is held in the barrel 25 of the secondary cooling chamber 6. In this way, the fuel element h° introduced into the secondary cooling chamber 6 and stored in the receiving position of the barrel 25 takes about 2 hours to advance to a position that corresponds to the fourth pass, which is the circumferential welding position. During this time, it is cooled down to a specified temperature. Then, the fuel element h° that has reached the circumferential welding position is sent out along the fourth line toward the welding chamber 33, and the welding chamber 3
At the circumferential welding section 34 of No. 3, circumferential end plug welding as described later is performed. When this circular welding is completed, the above-mentioned fuel, t4U element h
*:+) and returned to the secondary cooling chamber 6, and as the barrel 25 rotates, the outlet port 27 and the second outlet 1 co-boat 2
Proceed to the fifth line E corresponding to 9. During this period, the circulating welding part is heated to a suitable iE temperature, for example, about 50°C.
Cool to about °C. Then, since this fuel element is about this amount, it is fed through the gate valve 32 to the pressure welding part 35 of the welding chamber 33, and here the pressure welding as described later is performed.When this pressure welding is completed, the fuel is required.
is returned to the secondary cooling chamber 6, and then the gate valve 49 is
After the fuel element is transferred into the airlock chamber 51, which is opened and has a He gas atmosphere, the gate valve 49 is opened.
The air chamber 5 is closed and the exhaust device 55 is operated to exhaust the air chamber 5.
Switch the inside of 1 to a vacuum atmosphere. Thereafter, the gate valve 57 is opened to transfer the fuel t4 in the discharge airlock chamber 51 to the discharge airlock chamber 52 which is in a vacuum atmosphere. And the gate valve 5
7 is closed and the N1 gas supply device M, 59 is operated to perform N1 gas blowing in this dispensing air chamber 52, the atmosphere is made atmospheric, and the gate valve 61 is opened to open the dispensing lateral movement device. The fuel element is sent out to the decontamination device 53 by changing the wiring by this lateral movement device 53.

Here, we will briefly explain the end plug circumferential welding work mentioned in #3i.
is advanced from the secondary cooling chamber 6 side to a fixed position and gripped by the main chuck 36. After that, sub chuck 37
is moved from the standby position toward the fuel element to grasp the temporary end plug d, and in this state, the sub chuck 37 is returned to the standby position to remove the temporary end plug d from the stainless steel pipe b. Then, this temporary end stopper d is put into the collection box using the /\end 43. Furthermore, the hand 43 is operated to mount the spring e into the stainless steel pipe b, and the sub-chuck 37 is made to grip the main end plug f. After that, the sub chuck 3
7 toward the fuel element and press-fit the main end plug f into the open end of the stainless steel pipe b. Then, the welding torch 38 is opposed to the joint between the main end plug f and the stainless steel pipe b, and after checking whether the clearance is appropriate, a light shielding mask is set and circular welding is performed. That is, while the fuel element h° is rotated around the axis by the main chuck 36, the joint g between the end plug f and the stainless steel pipe b is welded airtight over the entire circumference.

Also, to briefly explain the pressure welding work mentioned above,
First, the fuel element that has been circumferentially welded is advanced from the secondary cooling chamber 6 side to a fixed position and is gripped by the main chuck 36. Thereafter, the main chuck 3θ rotates the fuel element around its axis to set and fix the welding point k at a fixed position. Then, the pressurizing chamber 41 is moved to airtightly enclose the end plug mounting portion of the fuel element in the pressurizing chamber 41, and a high-pressure (for example, about 30 atmospheres) He gas is contained in the pressurizing chamber 41. supply. As a result, the high-pressure He gas in the pressurized chamber 41 is filled into the fuel element through the small hole m formed in the end plug f.Next, the welding point k, that is, the open end of the small hole m The welding torch 42 is placed opposite the welding torch 42, and pressure welding is performed after checking the clearance. As a result, the small hole m is closed and high pressure He gas is electrically sealed within the fuel element.

As described above, degassing, He replacement, and end plug welding can be performed sequentially, but the end plug welding device comprising the secondary cooling chamber 6 and the welding chamber 33 is different from the conventional one. The difference is that it uses a continuous conveyance system. In addition to the population port 26 and the exit boat 27, there are two other ports in the cooling chamber 6.
It has two lead-in/out, tF-to 28.29, and a circumferential welding part 34 and a pressure welding part 35 provided at mutually different positions.
The welding process is applied to each part in turn.

Therefore, the conventional constraints of having to stop pressure welding when circular welding is being performed, and stopping circular welding when pressurizing welding are being performed, are eliminated. The welding process at the portion 34 and the pressure welding portion 35 can be continued continuously at all times. Therefore, it is possible to shorten the takt time and significantly increase the processing amount per unit of time. Moreover, if this is the case, the secondary cooling chamber 6 and the welding chamber 33 may be maintained in a constant He gas atmosphere at all times. Therefore, it is difficult for oxygen, moisture, etc. to be mixed into the He gas to be filled into the fuel element, the He gas can be easily managed, and the amount of He gas consumed can be significantly reduced. Therefore, high-purity He with low impurity gas components and moisture can be used.
It is possible to manufacture fuel elements filled with gas.

It should be noted that the shapes of the cooling chamber and the welding chamber are of course not limited to those of the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the present invention.

Further, in the embodiment described above, an inlet port and an outlet port are provided on one end wall of the cooling chamber, and a first and a second lead-in/out port are provided on the other end wall. It is not limited to such a boat arrangement.

(f) Effects Since the present invention has the above-described configuration, it is possible to sequentially and continuously perform the processing steps of circular welding, cooling, and pressure welding, thereby shortening the takt time and reducing the throughput. Therefore, it is possible to provide an end plug welding device for a fuel element that can be effectively increased without any problems.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining the manufacturing process of a fuel element, and FIG. 2b4 is a schematic perspective view showing an embodiment of the present invention. 6...Cooling room (secondary cooling room) 25...Barrel 26...Entrance boat 27...Fighting robot number 28/1st lead-out port 29...2nd lead-out port 33/・Welding chamber 34Φ... Circumferential welding section 35... Pressure welding section ri, h'... Fist fuel element representative Patent attorney Hiroshi Akazawa Figure 1 (C)

Claims (1)

[Claims] An inlet port for introducing a fuel element into an end wall of which has a He gas atmosphere inside, first and second inlet/outlet boats provided at different positions in phase 1, and an outlet port for introducing the fuel element. a barrel disposed within the cooling chamber for receiving a fuel element fed into the cooling chamber through the inlet port and sequentially translating the fuel element to a position facing each of the boats; an end plug provided with a welding chamber adjacent to the welding chamber and provided with a circumferential welding part in a portion corresponding to the first lead-out man boat and a pressure welding part in a part corresponding to the second lead-out man boat. A welding device, wherein when the fuel element held in the barrel reaches a first outlet port and a second outlet boat, the fuel element is temporarily welded and welded through a 111th orbit through the corresponding ports, respectively. The structure is such that the end plug of the fuel element heated by circular welding is pressure welded to reduce the distance between the first lead-in/out port and the second lead-out port. 1. An end plug welding device for a fuel element, characterized in that the temperature is set to a value that allows the fuel element to be cooled to an appropriate temperature by the time the fuel element reaches the end plug.