JPS62121388A - Tube washer - 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 This invention relates generally to fuel assemblies for nuclear reactors, and more particularly to cladding tubes for fuel rods. i! The present invention relates to an automated device for ultrasonic cleaning of cladding tubes used near the final process.

First out” 1 town! In many nuclear reactors, the reactor core includes a large number of elongated fuel assemblies. The conventional structure of these fuel assemblies is:
With grids spaced along the length of the fuel assembly,
It has a plurality of fuel rods held in an organized arrangement. The grid is simply installed to guide multiple control rods. The upper and lower nozzles at each end of the fuel assembly are fixed to guide simples extending up and down from both ends of the fuel rod.

Each fuel rod contains fissile material and is organized in such a way as to produce sufficient neutron flux within the core to maintain a high fission rate and thus release a large amount of energy in the form of heat. It is grouped into arrays consisting of All material present within the core of a nuclear reactor is irradiated by, and then interacts with, the fissile material within the fuel rods. In order to generate the required neutron flux in the reactor core, the interaction of the nuclei and the chemical composition of all components introduced into the reactor must be recognized and taken into account; therefore, all such configurations The materials that make up the components must be carefully chosen to obtain the required interaction with the neutron flux.

Extensive measures and measures are taken to control what materials are introduced into the reactor core, not only in the reactor equipment itself.
Part of the overall effort to achieve high standards of cleanliness that must be taken to maintain a clean environment in the facilities where the components are manufactured is to remove foreign material from the components manufactured. Cleaning of components inside. In the case of cladding tubes used in fuel rods, one of the final steps in their manufacture is thorough cleaning of the inner and outer surfaces of each cladding tube. Conventionally used cleaning techniques involve bundling together a large number of cladding tubes, for example 300, and immersing the bundle of cladding tubes in a tank containing a cleaning solution for a predetermined period of time to remove impurities from the surface of the cladding tubes. The process consists of immersing the bundle of cladding tubes in a rinsing tank in order to wash them away.

However, this conventional technique has several problems. First, commonly used tube cleaning solutions contain environmentally undesirable methylene chloride, toluene (+ethylene
Additionally, the process of collecting and bundling the cladding tubes is inherently inefficient and cumbersome, and the handling of large bundles of cladding tubes requires cranes and workers. Accordingly, there is a need to improve and automate methods for cleaning fuel rod cladding.

SUMMARY OF THE INVENTION The present invention provides an ultrasonic duct cleaning device designed to meet the above needs. Unlike the conventional batch process where the cladding is cleaned one bundle at a time,
This invention introduces a technique that operates on a first-in, first-out principle in which cladding tubes are processed individually in a relatively continuous manner. The cladding introduction, dipping and removal subsystems are:
Between the time each cladding pipe enters the pipe cleaning equipment and the time it exits,
It is virtually automatic so that there is no need for operator intervention. Also, as the cladding tube moves through the tank for cleaning, ultrasonic energy is transmitted to the cladding tube from a series of elongated transducers located at the bottom of the water-filled tank. This technology allows for cleaner cladding while simultaneously selecting biodegradable detergents with water and eliminating environmentally undesirable methyl chloride and toluene cleaning solutions. Although the invention is disclosed with respect to fuel rod cladding, it is also applicable to cleaning other tubes, such as control rod cladding. Hereinafter, the cladding tube will also be simply referred to as a tube.

Therefore, the present invention relates to a pipe cleaning device for cleaning pipes using ultrasonic waves, which includes (a) a cleaning tank for holding a certain amount of liquid, and (b) cavitation of the liquid in the cleaning tank by ultrasonic waves. means for generating energy; (e) tube feeding means for individually feeding the tubes into the liquid in the cleaning tank; and (d) tube feeding means for individually feeding the tubes through the cavitation energy within the liquid. (e) tube removal means for removing the tube from the liquid in the cleaning tank; and (e) tube removal means for removing the tube from the liquid in the cleaning tank. ing. The tubes are also individually fed into the liquid along folded paths. Additionally, the tubes are moved in single file across the wash tank within the liquid. The tubes are then similarly removed from the liquid in the wash tank one piece at a time. After the tube traverses the wash tank, it is held there and then removed.

More specifically, the tube is fed by means in the form of oppositely inclined upper and lower rails, these rails being
A folded passageway is defined along which the tubes are individually fed into the liquid in the wash tank. Additionally, a plurality of elongated, slightly sloped tracks at the bottom define a nearly straight path along which the tubes individually move through the ultrasonic cavitation energy in the liquid. be done. Note that the bottom rail is disposed below the upper and lower rails and across the cleaning tank.

Furthermore, the tubes are moved by means in the form of a plurality of flexible members adapted to move around an endless passageway extending between the tube movement means and the tube delivery position above the cleaning tank. taken out.

A pair of tube holders is attached to each of the flexible members in correspondence with the other pair of tube holders, with the tube holders of each pair on the same side adjacent to the tube delivery position. When placed in the non-loading position, the other tube holder is placed in the loading position adjacent to the tube movement rail. The tube receivers on the same side of each pair are adapted to pick up only one tube at a time.

The above and other advantages and effects of the invention will become apparent to those skilled in the art upon reading the following detailed description taken in conjunction with the drawings, which illustrate one embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the following description, the same reference numerals indicate the same or equivalent parts throughout the drawings. In addition, in the following explanation, "front", "rear", "left", "right",
Terms such as "upper" and "lower" are words of convenience and are not to be understood as limiting terms.

Referring to the drawings, and in particular to FIG. 1, a fuel assembly is shown generally by the numeral 10 in vertical double line form in front view. This fuel assembly 10 is a pressurized wooden nuclear reactor (
1) A type used in WR), which is basically a lower end structure for supporting a fuel assembly 10 on a lower core plate (not shown) in the core region of a nuclear reactor (not shown), that is, a lower nozzle 12 and , a plurality of guide tubes, ie, guide simples 14, project upward from the lower nozzle 12 and extend in the longitudinal direction. The fuel assembly 10 further includes a plurality of transverse gratings 16 axially spaced apart from each other along the guide simple 14 and an organization of elongated fuel rods 18 laterally separated from and supported by the gratings 16. It is equipped with a converted array. The fuel assembly 10 also includes an instrumentation pipe 20 disposed at its center, an upper end structure attached to the upper end of the guide simple 14,
That is, it is provided with an upper nozzle 22. Due to this arrangement of the components, the fuel assembly 10 forms an integral unit that can be handled normally without damage to the components.

As mentioned above, the array of fuel rods 18 in the fuel assembly 10 are held in a spaced relationship with each other by grids 16 spaced along the length of the fuel assembly 10. Each fuel rod 18 has an elongated hollow cladding tube 23 (second
The cladding tube 23 accommodates the nuclear fuel pellet 24 and is closed at both ends by an upper end plug 26 and a lower end plug 28 so as to hermetically seal the fuel rod 18. There is. - Finally, a plenum spring 30 is arranged in the cladding tube 23 between the upper end plug 26 and the fuel pellet 24 in order to hold the fuel pellet 24 in a tight, stacked relationship within the fuel rod 18; There is. 1 from fissile material
The fuel pellet 24, which is made up of 1/4 volts, is responsible for generating the reaction output of the PWR. A liquid moderator and coolant, such as water or boron-containing water, is passed through the guide simples 14 and along the fuel rods 18 of the fuel assembly 10 to extract the heat generated in the core and perform useful work. and then pumped upward.

In order to control the nuclear fission process, a number of control rods 32 are placed in the guide simple 1 at predetermined positions in the fuel assembly 10.
4, reciprocating movement is possible.

In particular - control I of the rod cluster associated with the upper nozzle 22! Lateral 34 is an internally threaded cylindrical member 36 having a plurality of radially extending flukes or arms 38.
have. Each arm 38 is connected to a control rod 32 and a control mechanism 34 is operative to move the control rod 34 vertically within the guide simple 14, thereby controlling the fission process in the fuel assembly 10, all in a manner well known. It is supposed to be done.

Here, in FIGS. 3 to 6, in order to completely clean the inner and outer surfaces of the cladding tube 23 of the fuel rod 18 as shown in FIG. 2 during the manufacture of the γζ tube 23, An ultrasonic duct cleaning device comprising a preferred embodiment of the present invention is designated generally at 40. The pipe cleaning device 40 basically consists of a volume of liquid 44, such as water, containing a suitable biodegradable synthetic detergent.
and means in the form of a series of transducers 46 disposed within the wash tank 42 for generating ultrasonic cavitation energy within the liquid 44 of the wash tank 42. There is.

More particularly, the elongated wash tank 42 includes a container 48 that includes a bottom plate 50, a pair of oppositely spaced vertical side walls 52, 54, and a pair of end walls. 56.58. In addition, these side walls 5
2.54 and the end wall 56.58 are connected to each other and
It is connected to the bottom plate 50. The vessel 48 is long and narrow rectangular to accommodate the long fuel rod cladding tube 23, and is typically 13 feet long. A container 48 holding a detergent-containing liquid 44 is also removably mounted within the external support shell 60 of the wash tank 42 . The external support shell 60 has a plurality of support legs 62 . - the transducer 46 is mounted in spaced relation on the bottom plate 50 of the wash tank 42 and extends between opposite end walls 56.58 of the wash tank 42, substantially parallel to the opposite side walls 52.54; arranged in a substantially linear pattern. As is known in the art, an ultrasonic transducer 46 is a device that converts electrical energy into mechanical energy. When the variable fa 346 is attached to the radiating surface, ie, to the bottom plate 50 of the container 48 of the cleaning tank 42, the mechanical energy is converted to cavitation energy by the hyperhepatic waves that effect the cleaning. The detergent contains liquid 4 in order to increase or accelerate the detergent action mainly performed by ultrasonic energy.
Used within 4.

Further, the pipe cleaning device 40 cleans the liquid 44 in the cleaning tank 42.
6 for feeding the cladding tubes 23 individually into
It is equipped with tube feeding means shown at 4.

This pipe feeding means 64 is an upper pipe artificial slope (upper slope)
and an intermediate pipe transfer slope (intermediate slope).

The upper slope is provided with a plurality of elongated inclined rails 70 for guiding the feeding of the cladding tubes 23 into the washing tank 42 in the form of a single file. The tracks 70 are preferably four in number and are generally parallel to each other and extend along one side wall 52 of the container 48.
From the top to the other side wall 54 it is sloped downwardly and laterally spaced from one another between the opposing end walls 56,58. Also, an elongated sleeve 72 is fitted into and extends between opposite end walls 56, 58 of the container 48 and pivots the rail 70 at a location adjacent the tube delivery end 74 of the rail 70. I support you. Additionally, spaced vertical support members 76 are provided on one side wall 52 of the container 48 at a height greater than the height at which the tube delivery end 74 of IJL, + 70 is attached by the shaft 72. In position, the tube holder of the track 70 connects to the outer support shell 60 adjacent the side wall 52 to receive the end 78 . The support member 76 is used to adjust the height of the end portion 78 of the rail 70 and to reduce the overall inclination i of the rail 870 (as shown by the imaginary line in FIG. 3). ) is vertically adjustable.

The intermediate slope receives the cladding 23 from the pipe delivery end 74 of the upper slope rail 70 and carries the liquid 44 in the wash tank 42.
A plurality of elongated inclined rails 80 are provided for guiding the feeding of the cladding tubes 23 in a single file therein. The rails 80 (shown only in Figure 3) are preferably 4
Pipe inlet ends 82 of wood, substantially parallel to each other and separated below the pipe delivery end 74 of the upper slope track 70
It is sloped downwardly from one side wall 52 of the container 48, with opposing end walls 56,58 laterally spaced from each other. Also, a pair of spaced apart elongated members 84 attached to and extending between opposite end walls 56,58 of the container 48 are provided at the tube inlet end 82 than at the tube outlet end 86. It supports the intermediate slope track 80 in a fixed slope position that is substantially elevated.

Furthermore, the pipe cleaning device 40 cleans the liquid 4 in the cleaning tank 42.
Each cladding tube 23 is provided with a tube moving means 88 for moving the cladding tube 23 across the cleaning tank 42 by 1.1 degrees within the liquid 44.
It passes through energy and is cleaned by the energy. The moving means 88 moves the lower pipe immersion slope (
(lower slope) having a plurality of elongated sloped rails 90 adapted to receive the cladding tube 23 from the outlet end 86 of the intermediate slope rail 80; The cladding tubes 23 are guided in a single file along a straight path across the cleaning tank 42 in the liquid 44 and above the transducer 46 installed in the cleaning tank 42.

The tracks 90 are preferably four in number and are substantially parallel to each other, with a pipe holder spaced below the pipe outlet end 86 of the mid-slope track 80 adjacent one side wall 52 of the vessel 4 at the end. Part 8
2 to the other side wall 54 and is slanted downwardly and laterally spaced between opposing end walls 56,58. Also, an elongated member 94 is attached to and extends between the opposing ends ri5B, 58 of the container 48, and the tube receiver of the rail 90 is attached to the opposite ends ri5B, 58 of the container 48, and
The lower sloped rail 90 is positioned adjacent the tubing end 96 such that the rail 90 is located against one side wall 52 of the container 48 at a position slightly higher than the height of the tubing end 96.
is supported. A triangular end stop 100 is attached to the tube end 96 of the track 90. It will become clearer in the following description, the end stop 10
0 is located at a position along the tube end 96 of the rail 90 that is calculated to ensure that only one cladding tube 23 is removed from the rail 90 at a time.

Finally, the tube cleaning device 40 connects the cleaning tank 42 to a tube delivery location 104, such as at an outlet cheeple (not shown).
A tube extracting means 102 is provided for extracting one cladding tube 23 at a time from the liquid 44 inside. The tube removal means 102 takes the form of a conveyor and is supported in a substantially vertical position on the side wall 54 of the container 48.

The conveyor 102 picks up one cladding tube 23 at a time at the sump iγC end 96 of the track 90 on the lower slope, and the liquid 44 transfers the cladding tube 23 to the tube delivery position 104 above the cleaning tank 42. The cleaning tank 42
5 from the cladding tube 2: (after taking out the other cladding tube 2
3 is picked up by a conveyor 102.

More particularly, the conveyor 102 includes a plurality of visible drive chains 106, preferably three;
Each chain 106 is wound between an upper drive sprocket 1-108 and a lower sprocket 110. The lower sprocket 110 is rotatably housed between the lower brackets 114, and these lower brackets 114 are housed in the side wall 54 of the container 48 below the surface of the liquid 44 in the cleaning tank 42. is attached. The upper drive throttle rocket 108 is secured to a shaft 116 rotatably mounted to the upper bracket 1-118 of the side wall 54 above the water level, and
16 is driven by a drive unit 120. Drive chain 106 and subrocket! -108, 110 extend substantially parallel to each other and are laterally spaced 1 meter from each other between opposite end walls 56,58 of the container 48.

Each drive chain 106 has a pair of tube receivers 122 housed therein. Each tube receiver 122 is seated on drive chain 106 at a distance from the other tube receiver 122 equal to approximately half the length of drive chain 106 . The drive chain 106 is connected to the track 90 on the lower slope.
a substantially parallel endless endless pipe 3I extending between the free end 96 of the pipe arrangement and the upper pipe delivery position 104 of the wash tank 42;
It defines TIn. ii■Flexible drive chain 10
Pipe holders housed in each of the 6! 22, the upper of the pair of tube receivers 122 housed in each drive chain 106 is adjacent to the tube delivery position 104, as shown in FIG. When the tube receiver 122 is placed in the upper tube-free position, the lower side of the tube receiver 122 is placed at the tube device end 96 of the lower sloped rail 90, as shown in FIGS. 3 and 6. It is located at the tube device location just below the end stop lOO. In this way, the corresponding ones of the tube supports 122 are unpaired and are
, N tubes 23 Only all 23 can be picked up, and after holding it at the tube delivery position 104 and letting it burn, the other cladding tubes 23 can be picked up.

In addition, the pipe cleaning device 40
A pump/filtration device (not shown) is provided to circulate and filter the liquid 44 in the wash tank 42 in order to remove the washed +A material from the wash tank 42.

From above, approximately II'f is fed into the wash tank 42 via the turn-around passage defined by the rails 70, 80 of the upper and middle slopes and ascends to the rails 90 of the lower slopes.
An end stop 100 is inserted into the liquid 44 in a linear path.
It will be appreciated that the cladding tube 23 has a weight that can be carried up to . A sensor (not shown) is attached to the rail 70.
80,90 and are preferably strategically placed along the drive chain 106 to monitor the flow of each cladding tube 23 through the wash tank 42; signals from these sensors are sent to a controller (not shown); The controller tracks the movement of each cladding tube 23 and initiates the unloading of each cladding tube 23 by starting the drive unit 120 to drive the drive chain 106 at the appropriate time. In this way, each cladding tube 23, like all other cladding tubes, is immersed in ultrasonic cavity energy for the same predetermined length of time. Cladding tube 23
Also, based on the first-in-first-out principle, the cleaning tank 42
taken from.

To drain the liquid from the interior of the cladding tube 23, one of the drive chains 106 is momentarily slowed down or stopped while the other drive chain 106 continues to move. Each movement of the drive chain 106 is then reversed to relevel the cladding tube 23. After being leveled again, the cladding tube 23 is moved to the top of the upper drive sprocket 108, in this position the drive unit 120 is stopped and the cladding tube 2:3 is placed in the plane of the tube delivery position i:104. Rolled over.

The invention and its many attendant advantages will be appreciated from the above description. It will be apparent that various changes may be made in form, structure, and arrangement without departing from the spirit and scope of the invention or sacrificing its substantial advantages, and therefore The embodiments described above are merely preferred embodiments of the invention.

[Brief explanation of drawings]

FIG. 1 is a vertically truncated front view, partially truncated for clarity, showing a fuel assembly comprising fuel rods with cladding that is cleaned during manufacture according to the present invention; FIG.
3 is a perspective view of a typical cladding tube of a fuel rod that can be cleaned by the apparatus of the present invention, FIG. 3 is an end view of the tube cleaning apparatus of the present invention, and FIG. 4 is a 3Lll! Fig. 5 is a plan view of the pipe cleaning device taken along line 4-4 in Fig. 4;
rV is a partially enlarged detailed m1 view of the tube take-out means in FIG. 5 taken along line 6-0 in FIG. Cleaning device 42, cleaning tank 44: Liquid 46/Converter 48: Container 64 Pipe feeding means 70, 80, 90: Rail 88: Etc. moving means 102: Pipe extraction means (conveyor) □1-1 Patent application fee F ! 1! Who is this person? FI
G, 3 FIG, 6

Claims (1)

[Scope of Claims] A pipe cleaning device for cleaning pipes with ultrasonic waves, which includes (a) a cleaning tank that holds a certain amount of liquid, and (b) cavitation and cavitation of the liquid in the cleaning tank by ultrasonic waves. (c) tube feeding means for individually feeding said tubes into said liquid in said cleaning tank;
tube moving means for moving the tube across the cleaning tank in the liquid so as to pass through the energy and be cleaned by the cavitation energy; (e) from the liquid in the cleaning tank; A pipe cleaning device comprising: a pipe take-out means for taking out the pipe; and a pipe cleaning device.