JPH01195396A - Equipment and method for fuel replacement - Google Patents

Abstract

PURPOSE:To prevent scattering of sodium mist by installing a running rail in a furnace upper chamber and providing a fuel holding part which is supported by a longitudinally and transversely expansible supporting means on this running rail. CONSTITUTION:A fuel replacing device 17 consists of a truck part 40 placed on a running rail 16 and a fuel handling part 41 suspended from the truck part 40, and the fuel handling part 41 is provided with a link type expansible arm 43 which supports the fuel holding part, namely, a gripper 42 expansibly in the transverse direction and an expansible cylinder part 44 which supports the expansible arm 43 expansibly in the longitudinal direction. When the fuel replacing device is moved, the expansible arm 43 is contracted and the expansible cylinder part 44 is contracted to store this part 44 in a case 47. A sodium pan 50 is freely openably and closably provided in the lower open end of the case 47, and sodium accumulated in the pan 50 is removed by a sucking device 53 through a sodium drain line 51, thus preventing scattering of sodium.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a hot cell type refueling equipment and method for a fast breeder reactor, and particularly to a fuel exchange system suitable for reducing the space above the reactor and preventing scattering of sodium mist inside the reactor. Relating to exchange equipment and methods.

[Conventional technology]

FASt breeder 5yste1 is a hot cell type refueling equipment for conventional fast breeder reactors.
1s: Experience Galned and
Path to Economical Power
Generation, 5eptember 13-
17.1987. There is a device described in PP9.5-1 to 9.5-6, and its configuration is shown in FIG. 12. In this figure, 1 is a reactor core, and fuel bots 2
is installed. An opening 4 communicating with the upper furnace chamber 3 is formed in the upper part of the furnace, and the opening 4 has an upper furnace mechanism part UIS.
(uDDflr 1internal 5tructu
re) 5 is located. Lower furnace mechanism 5 of upper furnace chamber 3
A UIS lifting device 6 is installed above the furnace, and a crane-type fuel exchanger 7 is installed in the upper furnace chamber 3.

At the time of fuel exchange, after the operation is stopped, the upper part of the furnace upper part ai:f15 is lifted by the UIS lifting device 6, and the opening 4 in the upper part of the furnace is opened.Then, the crane-type fuel exchange machine 7 is moved near this opening 4. , fuel exchange R from opening 4
7 to move the fuel in the core 1 or to the fuel bot 2.

The fuel transferred to the fuel bot 2 is taken out through the lower furnace opening 4, passes through the upper furnace chamber 3, and is transported to a fuel storage facility.

[Problem to be solved by the invention]

In this conventional equipment, fuel exchange is performed through the lower furnace opening 4.
Since the fuel exchange is carried out by a crane-type refueling R7 that is vertically lowered from the reactor core 1, the diameter of the lower reactor opening 4 is
The diameter of the fuel bot 2 added to the diameter of the fuel bot 2 installed outside the fuel bot 2 is required. For this reason, the opening area of the opening 4 becomes large, and there is a problem in that the sodium mist in the furnace is scattered from the opening 4 into the upper furnace chamber 3 during fuel exchange.

Also, crane type fuel exchanget! 17 has a wide movable range, so the upper furnace chamber 3 needs to be wide enough to accommodate the movable range, and the space in the upper furnace chamber 3 becomes large, and the furnace is suspended above the opening 4 during fuel exchange. Since the lower mechanism 5 is located, there is a problem in that it is difficult to perform fuel exchange using a crane type fuel exchange 1!17.

An object of the present invention is to provide fuel exchange equipment and a method that can suppress the scattering of sodium mist and smoothly perform fuel exchange within the limited space of the upper reactor chamber.

[Means to solve the problem]

The above purpose is to install a running rail in the upper chamber of the furnace, to have a fuel holding part supported by support means that is expandable in the horizontal and vertical directions on the running rail, and to install a fuel exchange machine and a fuel inlet/outlet machine. This is achieved by a fuel exchange facility characterized by a movably mounted fuel exchange device that also serves as a fuel exchange device.

The support means for the fuel holding part preferably includes a telescoping arm that supports the fuel holding part so that it can expand and contract in the horizontal direction, and a telescoping cylinder that supports this telescoping arm so that it can expand and contract in the vertical direction. The refueling device also has a case that accommodates the support means together with the fuel holding portion in the retracted state of the support means.

The traveling rail is configured such that a portion located above the furnace opening can be extended with respect to other portions. In addition, the upper furnace chamber has a storage space in which the lower furnace mechanism that is lifted up during fuel exchange is located, and adjacent to this storage space, there is a sodium hydride that can be opened and closed to separate the storage space from other parts of the upper furnace chamber. A saucer is provided.

At the time of fuel exchange, the atmosphere in the furnace upper chamber is preferably replaced with nitrogen gas. At this time, preferably, the temperature of the nitrogen gas in the upper furnace chamber is kept at a high temperature of about 150°C, except for the area around the lower furnace mechanism lifted for fuel exchange JA, and the temperature around the lower furnace mechanism is at the temperature during normal operation. The temperature shall be approximately 50°C.

[Effect]

The fuel exchange device on the running rail installed in the upper furnace room is
The fuel exchange device moves on the rail to exchange fuel. At this time, the fuel exchange device extends the support means in the vertical direction, lowers the fuel holding part into the furnace through the lower opening of the furnace, and extends the support means in the horizontal direction. The fuel retainer is moved over the required range of the core, which allows the opening at the bottom of the reactor to be made smaller. Furthermore, when inserting into the furnace and moving, the supporting means and the fuel holding section are housed in the case and moved. Therefore, the fuel exchange device becomes compact, so that the opening at the bottom of the furnace can also be made smaller. By making the lower furnace opening small in this way, it is possible to reduce the scattering of sodium mist from the inside of the furnace to the upper furnace chamber.

In addition, by moving the fuel exchange device on a running rail to perform fuel exchange, and by storing the fuel holding part in a case and moving it, fuel can be exchanged within the limited space of the upper reactor chamber. can be done smoothly.

During fuel exchange, the atmosphere in the upper chamber of the furnace is replaced with nitrogen gas. Nitrogen gas is inexpensive, has a light specific gravity, and is lighter than Ar gas, which is the sodium cover gas in the furnace. By setting the temperature of the nitrogen gas in the upper chamber of the furnace to about 150° C., the specific gravity of the nitrogen gas becomes even lighter. Therefore, this also prevents the sodium mist in the Ar gas in the furnace vessel from scattering into the upper chamber of the furnace. By separating the area around the upper furnace mechanism in the upper furnace chamber from other parts with a sodium tray, sodium mist around the upper furnace all side is prevented from adhering to other electrical parts, etc. The nitrogen gas atmosphere above the melting temperature of the sodium mist prevents the sodium mist from adhering to the walls of the upper furnace chamber.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a core of a fast breeder reactor. The core 10 is arranged at the center of a reactor vessel 11, and a fuel bot 12 is arranged around the outer periphery of the core 10. At the top of the reactor core 10 there is an upper reactor RM, or UIS (upper 1nte).
The upper furnace structure 13 is located in a relatively small diameter opening 15 that communicates with the upper furnace chamber or cell chamber 14 .

A traveling rail 16 is installed in the cell chamber 14, and a fuel exchange device 17 serving as a fuel exchanger and a fuel inlet/output device is movably mounted on the traveling rail 16, as will be described later.

The traveling rail 16 is configured such that a portion located above the furnace opening 15 can be extended with respect to other portions in order to enable lifting of the furnace upper mechanism 13. in particular,
For example, it can be configured as shown in FIGS. 2 to 4. That is, the running rail 16 is composed of a fixed rail 21 fixed to a building 20 and a movable rail 22 that is movable in the longitudinal direction with respect to the fixed rail 21, and the movable rail 22 is normally shown in FIG. It is made to stand by at the retracted position below the fixed rail 21. At this position, the tip of the moving rail 22 is supported by the rail support stand 23. The rail support base 23 is provided with a height adjustment means 24 (see FIG. 4) such as a fluid cylinder.

After lifting the furnace upper mechanism 13 in this state, the movable rail 22 is pushed out toward the rail pedestal 25 attached to the building 20 opposite the fixed rail 21, and the tip of the movable rail 22 is moved as shown in FIG. 0 is placed on the pedestal 25, then
The height of the rear end of the movable rail 22 is adjusted by the height adjusting means 24 of the rail support stand 23, and the movable rail 22 is combined with the tip of the fixed rail 21 on a straight line and fixed integrally.

In the upper part of the furnace upper mechanism 13 of the cell chamber 14 in the upper furnace,
A storage space 30 is provided in which the upper reactor mechanism 13 that is lifted up during fuel exchange is placed, and a UI is installed on the ceiling of this storage space 30.
An S lifting device 31 is installed. Also storage space 3
A sodium tray 32 that can be opened and closed is provided on the ceiling of the cell chamber 14 adjacent to the storage space 30 at the bottom of the storage space 30. During fuel exchange, the storage space 30 and other parts of the cell chamber 14 are separated by this tray 32. It will be done.

The fuel exchange device 17, as shown in FIGS. 5 and 6,
Consisting of a truck portion 40 placed on the traveling rail 16 and a fuel handling portion 41 hanging down from the truck portion 40, the fuel handling portion 41 is a link that supports a fuel holding portion, that is, a gripper 42 so as to be expandable and retractable in the lateral direction. It has a telescoping arm 43 of the type, and a telescoping cylindrical portion 44 that supports the telescoping arm 43 so as to be extendable and retractable in the vertical direction. The gripper 42 is a telescopic arm 4
3, and is linked to a gripper arm 45 that operates the gripper 42. The telescoping arm 43 is connected to an arm moving shaft 46 as shown in FIGS. 7 and 8, and is operated by moving the arm moving shaft 46 up and down. The fuel handling portion 41 also has a case 47 for storing the telescoping arm 43 and the telescoping tube portion 44 together with the gripper 42 and fuel in the retracted state.

When moving the fuel exchange device, as shown in FIGS. 5 and 7, the telescoping arm 43 is retracted, and the telescoping arm 43, the gripper 42, and the gripper arm 45 are housed in the lowermost cover 44A of the telescoping cylinder section 44. And, by contracting the telescopic cylinder part 44, it is retracted! The cylindrical portion 44 is housed in the case 47 together with the above-mentioned members. At the time of fuel exchange, please refer to Figures 6 and 8.
As shown in the figure, the telescopic cylindrical arm 43 and the telescopic cylindrical part 44
is extended, the gripper 42 and the gripper arm 45 are taken out laterally from the telescoping cylinder part 44, and the fuel is exchanged.

A sodium receiving tray 50 is provided at the lower open end of the case 47 so as to be openable and closable, and a sodium drain line 51 and vapor trap piping 52 are provided at the lower part of the case 47.
are connected to a sodium suction device 53 and a vapor trap 54, respectively, which are installed on the truck portion 40. The sodium tray 50 is open during fuel exchange, and the sodium tray 50 is open when the fuel exchange device is moved.
is closed and functions as a tray for sodium dripping with the gripper etc. stored in the case 47. The sodium accumulated in this tray 50 is removed by the suction device 53 via the sodium drain line 51. . Further, the sodium vapor in the case 47 is also removed by the vapor trap 54 via the vapor trap piping 52.

An example of the structure of the gripper 42 is shown in FIG.
The gripper 42 includes a gripper cylinder 60 and a gripper cylinder 6.
The gripper shaft 61 includes a gripper shaft 61 that moves up and down within the gripper body 60, and a support 65 that is pivotally attached to the gripper body 60 with a pin 62 and is moved by the large diameter portion 63 at the tip and the large diameter portion 64 at the rear of the gripper shaft 61.

The gripper body 60 is inserted into the upper end of the arm tube section 43A described above, and the gripper shaft 61 is linked to the gripper arm 45 described above. A hole 67 is formed on the inner periphery of the upper end of the fuel rod or fuel bot 66, into which the tip of the support 64 enters.

When gripping a fuel rod or fuel bot 66, operate the gripper arm 45 to move the gripper shaft 61 to the illustrated position, and use the large diameter portion 63 at the tip of the gripper shaft 61 to grip the support 6.
5 from the inside, and hook the tip of the support 65 to the stopper 67 of the fuel rod or fuel bot 66. To remove the fuel rod or fuel bottle 66, move the gripper shaft 61 downward, push the rear protrusion in the gripper barrel of the support 65 with the rear large diameter portion 64, move the tip of the support inward, and remove the support. In this way, by moving the gripper shaft 61 up and down, the fuel rod or fuel boat 66 can be gripped and released.

In reality, the fuel rods and fuel bots have different diameters, so two grippers 42 are used that match the respective diameters.
Similarly, two sets of telescopic arms 43 and gripper arms 45 are prepared.

The spent fuel transfer route in which the fuel exchange equipment of this embodiment is arranged will be explained with reference to FIG. 10.

The fuel is taken out from the core 10 by the fuel exchange device 17 and inserted into the fuel bot 12 at the outer periphery of the core.
The entire product is taken out of the furnace and transferred to canning equipment 70. The fuel exchange device 17 also serves to transfer new fuel contained in the fuel bot into the reactor.

In the canning facility 0i70, the fuel bot 12 into which the fuel has been inserted is covered. This canned fuel is Incel Crane 71
The canned fuel is transported to the spent fuel underground truck 72 while being gas-cooled.

The spent fuel transfer lane 73 is a spent fuel underground trolley 72.
The fuel is lifted from the tank and placed in the spent fuel storage facility 74.

Next, the procedure of fuel exchange using the fuel exchange equipment of this embodiment will be explained with reference to FIGS. 11(A) to 11(D).

After the operation was stopped, the TJ was installed to prepare for lifting the lower reactor mechanism 13.
The IS lifting device 31 is attached to the upper part of the furnace 111113.

In addition, the inside of the cell chamber 14 in the upper part of the furnace is replaced with nitrogen gas, and the temperature inside the cell chamber is adjusted to reduce the specific gravity of the nitrogen gas and raise the sodium mist to above the melting temperature to prevent it from adhering to the cell chamber wall. From around 50℃ to 150℃
Keep it at a moderate temperature.

Next, as shown in FIG. 11 (8), the upper furnace mechanism 13 is lifted up by the UIS lifting device 31, and the UIS lifting device 31 (not shown) is lifted up.
The lower furnace mechanism 13 is fixed in the storage space 3o of the cell chamber 16 using a fixing device so that there is no problem in terms of earthquake resistance.

In addition, the moving rail 22 of the traveling rail 16 is extended and installed to the upper part of the furnace (see Fig. 4), and the upper furnace machine fJ13
A sodium receiving tray 32 is installed inside the furnace upper chamber 14 to prevent sodium adhering to the furnace from dripping into the upper furnace. This sodium receiving tray 32 is located in the upper furnace m in the upper furnace cell chamber 14.
It also serves as a seal between the space 30 that accommodates the side 13 and other parts. That is, since the storage space 30 in the furnace upper part 641113 is set at about 150°C as described above, the sodium adhering to the furnace upper R top 13 etc. becomes sodium mist and scatters in the cell chamber 14, causing CRDM, etc. There is a risk of adhesion to electrical parts. By installing the storage space 30 to the cell chamber 14, the storage space 30 is isolated from the cell chamber 14, and sodium mist is prevented from scattering into the cell chamber 14, and the temperature inside the storage space 30 is kept as low as 50℃ during operation.
The generation of sodium mist itself can be reduced by keeping the temperature at a low temperature of about ℃.

On the other hand, since the nitrogen gas in the furnace upper cell chamber 14 is kept at a high temperature of about 150° C., the sodium mist in the cell chamber 14 reaches a temperature higher than its melting temperature and is prevented from adhering to the cell chamber wall surface. Nitrogen gas has a light specific gravity, but by heating the light nitrogen gas to a high temperature of 150°C, the specific gravity becomes even lighter.
5 to prevent sodium mist from flowing into the cell chamber 14 from inside the furnace through the opening 15. Note that in order to prevent the nitrogen gas atmosphere from flowing into the furnace vessel 11, a small amount of Ar gas is purged into the furnace.

Next, the fuel exchange device 17 is moved above the furnace lower opening 15 as shown in FIG. 11(B), and the fuel exchange device 17
The telescoping cylindrical portion 44 is extended and its tip is lowered, and the telescoping arm 43 is extended laterally (see FIGS. 5 and 6). Since the fuel is taken out, no in-core storage facility is provided.The fuel is first pulled out from a predetermined position in the core 10 by the gripper 42 of the fuel exchange device 17, as shown in FIG. 9 inserted into the bot 12 installed in Figure 11 (
0), remove the fuel along with the bot 12 from the furnace,
As described above, the fuel exchange device 17 is provided with a sodium tray 50 and a sodium tren line 51 for receiving sodium dripping from the bot 12. The bot 12 filled with fuel is transported to the aforementioned fuel canning facility 70 (see FIG. 10) while being cooled by a nitrogen gas cooling system provided in the fuel exchange device 17.

Sodium mist appearing in the cooling nitrogen gas is removed by vapor trap piping 52 and vapor trap 54 so as not to be released into furnace upper chamber 14.

New fuel is first put into the fuel bot 12 and inserted into the bot 12 in the furnace using the fuel exchange device 17.

Next, grab fuel with the same fuel exchange device 17 and bot 1
2 and insert it into the specified position in the furnace.

In this way, the fuel exchange device 17 moves on the traveling rails 16, transports fuel from the upper part of the reactor core to the canning equipment, and also serves as an in-cell crane by transporting new fuel into the reactor.

After the above fuel exchange is completed, the lower furnace mechanism 13 is restored by performing the reverse procedure from shutdown to fuel exchange.

In this way, the fuel exchange device 17 performs loading/unloading and exchanging of fuel using support means 43 and 44 that are expandable and retractable in the vertical and horizontal directions, and also stores the support means, gripper 42, etc. in the case 47 when moving. Move in a compact form. As a result, the lower furnace opening 15 can be made smaller as shown in FIG. 1, etc., and scattering of sodium mist from the inside of the furnace to the upper furnace chamber 14 can be reduced. Therefore, in combination with the use of nitrogen gas and its high temperature, it is possible to effectively prevent the sodium mist in the furnace vessel 11 from scattering into the upper furnace chamber 14. In addition, by moving the fuel exchange device 17 on the running rail 16 to perform fuel exchange, and by storing the gripper 42 and the like in the case 47 and moving it, fuel exchange can be performed within the limited space of the upper reactor chamber 14. can be done smoothly.

〔Effect of the invention〕

As is clear from the above, according to the present invention, it is possible to reduce the size of the opening at the bottom of the furnace and to prevent the scattering of sodium mist by the nitrogen gas and sodium tray. Additionally, the compact fuel exchange device that moves on running rails allows for smooth fuel exchange within a limited space.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fast breeder reactor including a refueling facility according to an embodiment of the present invention, FIG. 2 is a top view of the running rail of the refueling facility, and FIG. 3 is a top view of the running rail of the refueling facility. FIG. 4 is a side view showing an extended state of the traveling rail, FIG. 5 is a partially sectional side view of the fuel exchange device of the fuel exchange facility, and FIG. 6 is a side view of the fuel exchange device. 7 is a sectional view of the lower end of the fuel handling portion of the fuel exchange device shown in FIG. 5; FIG. 8 is a side view of the fuel exchange device shown in FIG. 6; FIG. FIG. 9 is a sectional view of the lower end of the fuel handling portion of the device, FIG. 9 is a sectional view of the gripper of the fuel handling portion, and FIG. 10 is a diagram showing the fuel transfer route where the fuel exchange equipment of the present invention is arranged. , FIG. 11(A) to FIG. 11(D) are process diagrams showing a fuel exchange procedure using the above fuel exchange equipment,
FIG. 12 is a sectional view of a nuclear reactor showing conventional fuel exchange equipment. Explanation of symbols 10...Core 12...Fuel pot 13
Furnace upper mechanism 14 Furnace upper chamber (cell chamber) 15 Opening 16 Running rail 17
. . . Fuel exchange device 22 . . . Moving rail (extendable part) 30 . . . Storage space 32 .・・・Extensible cylinder part (supporting means) 47 ・・・Case applicant Hitachi, Ltd. Representative Patent attorney Yuzuru Kasuga Figure 9 Figure 11

Claims (9)

[Claims] (1) In a hot cell type refueling facility for a fast breeder reactor, a running rail is installed in the upper chamber of the reactor, and a fuel holding section is supported on the running rail by a supporting means that is expandable in the horizontal and vertical directions. What is claimed is: 1. A fuel exchange facility characterized in that a fuel exchange device serving as a fuel exchange machine and a fuel inlet/output machine is mounted in a movable manner. (2) The supporting means is comprised of a telescoping arm that supports the fuel holding portion so that it can expand and contract in the horizontal direction, and a telescoping cylinder that supports the telescoping arm so that it can expand and contract in the vertical direction. The fuel exchange equipment described in 1. (3) The fuel exchange equipment according to claim 1 or 2, wherein the fuel exchange device has a case that accommodates the support means together with the fuel holding portion when the support means are in a contracted state. (4) The fuel exchange equipment according to claim 1, wherein the traveling rail is configured such that a portion located above the furnace opening can be extended with respect to other portions. (5) The upper furnace chamber has a storage space in which the upper furnace mechanism lifted during fuel exchange is located, and is adjacent to this storage space and can be opened and closed to separate the storage space from other parts of the upper furnace chamber. 2. The fuel exchange equipment according to claim 1, further comprising a sodium receiving tray. (6) A fuel exchange method characterized in that the atmosphere in the furnace upper chamber according to claim 1 is replaced with nitrogen gas at the time of fuel exchange. (7) A refueling method in a hot cell type refueling facility for a fast breeder reactor, characterized by replacing the atmosphere in the upper chamber of the reactor with nitrogen gas during refueling. (8) The fuel exchange method according to claim 5 or 6, characterized in that the temperature of the nitrogen gas in the furnace upper chamber is raised to a high temperature. (9) The fuel exchange method according to claim 7, wherein the temperature of the nitrogen gas is about 150°C.