JPH01184499A - Parts cleaning device for control rod drive mechanism - Google Patents

Abstract

PURPOSE:To efficiently clean the inside and outside surfaces of the small parts of a control rod drive mechanism to which radioactive clads are stuck by injecting a cleaning liquid to the inside and outside surfaces of the rotating parts to be cleaned, thereby automatically and continuously cleaning said parts. CONSTITUTION:The cylindrical small parts of the CRD to which the radioactive clads are stuck are loaded on respective parts receiving bases of a cleaning tank 11. A motor is then driven to simultaneously rotate the parts receiving bases, then a circulation pump 53 and a high-pressure feed water pump 42 are driven to start cleaning of the parts. The cleaning water is regulated to a prescribed flow rate by a regulating valve 45 on the down stream of the pump 42 and is then regulated in flow rate by respective regulating valves 46, 47, 48 of branch pipes 41a-41c. This cleaning liquid is supplied to a nozzle 31 for cleaning the outside surfaces of the parts, a nozzle 32 for cleaning the inside surface of the parts and a nozzle 33 for cleaning the inside of the tank. The liquid is injected in the form of the high-pressure cleaning water of the prescribed flow rate from the respective nozzles into the cleaning tank 11. The small parts of the CRD which are loaded on the parts receiving bases and to which the radioactive clads are stuck are thus simultaneously cleaned in the total number from the inside and outside surfaces thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objectives of the Invention) (Industrial Application Field) The present invention relates to an apparatus for cleaning components of an ill II rod drive mechanism, and in particular small parts of cylindrical or similar shape. The present invention relates to a parts cleaning device for a control rod drive mechanism suitable for cleaning.

(Prior art) The control rod drive mechanism (CRD) of a boiling water reactor is generally of the hydraulic type, and consists of a CRD housing installed at the bottom of the reactor pressure vessel and a CRD housing inserted into the housing. Large parts such as outer duplex, index duplex, cylinder duplex, piston duplex, drive piston, outer filter, inner filter, guide cap,
It is composed of small cylindrical parts such as a coupling spud and a strainer. Radioactive crud, etc. adhere to the parts of such CRDs that come into contact with reactor water, and gradually release rJ41.
Since the amount of oil increases by 1 rubel, it is cleaned in advance during periodic inspections, etc.

When disassembling and cleaning, the CRD that has been removed by the CRD exchanger is first immersed in a cleaning and decomposition tank, and while taking radiation shielding measures, the large parts are cleaned and disassembled. Next, the disassembled small parts are transferred to a parts washing machine and further cleaned to sufficiently reduce radiation levels.

Conventionally, such a parts cleaning bag δ generally has a structure shown in FIG. That is, an ultrasonic cleaner 2 is provided in a cleaning tank 1 capable of accommodating small parts of the CRD, and a water supply pipe 4 having a large mouth valve 3 is connected to the cleaning tank 1. Also, cleaning tank 1
A waste treatment system 7 is connected via a drainage pipe 6 having an outlet valve 5 at the bottom. In addition, washing I! The upper part of 111 and the drainage pipe 6 are connected by an overflow pipe 8.

During cleaning, the large mouth valve 3 is opened, cleaning water 9 is supplied from the water supply pipe 4 into the cleaning phase 1, the parts to be cleaned are submerged in the cleaning water 9, and the ultrasonic cleaner 2 is operated. As a result, the radioactive cladding 10 that has fallen off from the parts to be cleaned is removed from the cleaning tank 1.
It settles to the bottom of the tank.

After such cleaning work is completed, the outlet valve 5 is activated, and the cleaning water 9J and the radioactive cladding 10 are transferred to the waste treatment system 7 via the drainage pipe 6, and waste liquid treatment is performed.

Next, the washed parts are taken out from the washing tank 1, the outlet valve 5 is closed, the large mouth valve 3 is opened again, and washing water is newly supplied from the water supply pipe 4 to wash other parts in the same manner as described above. Repeat the work. Note that the excess supply of cleaning water 9 is discharged through an overflow pipe 8, and a constant amount of cleaning water is always maintained in the cleaning tank 1.

(Problems to be Solved by the Invention) In the conventional parts cleaning apparatus described above, the posture of the parts to be cleaned remains substantially constant during cleaning, and the cleaning action is difficult to reach inside the parts. Therefore, it takes a long time to complete one cleaning operation. In some cases, the inside of the parts may not be completely cleaned and manual brush cleaning may be required, but this results in extremely low work efficiency in terms of preventing exposure to radiation.

Furthermore, since the cleaning is a batch process, and the cleaning water is replaced every time, the amount of waste treatment system to be processed increases, and the volume load may temporarily rise sharply and exceed the processing capacity.

The present invention was made in view of these circumstances, and
Not only can you efficiently and reliably clean parts D, but you can also efficiently dispose of cleaning fluid waste! The purpose of the present invention is to provide a parts cleaning device for controlling and driving GL.

[Structure of the invention]

(Means for Solving the Problems) A control rod drive mechanism parts cleaning device according to the present invention includes a radiation shielding means for cleaning parts of a tlJ III cup drive mechanism having a cylindrical shape or other shape having inner and outer surfaces. The component holder includes a stand for mounting and rotating the component in a cleaning tank, the component holder includes a component outer surface cleaning nozzle that injects cleaning liquid onto the outer surface of the component on the pedestal, and the component holder protrudes above the table to remove the component. A component inner surface cleaning nozzle that spouts cleaning liquid onto the inner surface is provided, and a cleaning liquid regeneration and circulation device that receives the used cleaning liquid from the cleaning tank, filters it, and supplies it to each of the nozzles as clean cleaning liquid. It is characterized by

Preferably, the cleaning tank is provided with a directional cleaning nozzle for cleaning the inner surface of the cleaning tank.

(Function) The small parts to be cleaned are mounted on the table with the parts receiver arranged so that its inner surface surrounds the parts inner surface cleaning nozzle. In this state, the parts receiver rotates the stand and jets the cleaning liquid onto the inner and outer surfaces of the small parts from the parts inner surface cleaning nozzle and the component outer surface cleaning nozzle. As a result, solid matter such as radioactive cladding attached to small parts is washed and removed. The used cleaning liquid containing crud etc. is led from the cleaning tank to the cleaning liquid recycle circulation bag j,
Shun normalized by filtration, reflux to each nozzle.

Then, the parts are cleaned again.

That is, small parts can be efficiently, rapidly and reliably cleaned continuously using a relatively small amount of cleaning liquid.

Crud, etc. that fall into the cleaning tank are cleaned with cleaning liquid jetted from the cleaning nozzle in the tank.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows the mechanical configuration of a CRD parts cleaning device.

As shown in FIG. 1, in the parts cleaning apparatus of this embodiment, the cleaning tank 11 has a tank main body 12 with an opening at the top and an M2 which covers the opening.
It has C. The lid 13 is rotatably attached to the tank body 12 by a hinge 14, and a sealing gasket 15 is provided on the inner surface of the lid 13. A shielding wall 16 as a radiation shielding means is provided on the outer surface of the tank body 12 and the lid 13.
17 are provided for each.

At the bottom 11a of the cleaning tank 11, a plurality of parts receivers 18 are provided, for example, in an annular arrangement. These six parts receivers 18 are disk-shaped and arranged horizontally, each having a flange 19 for holding parts on the peripheral edge of the upper surface, and rotatable via a bearing 20 to the following parts inner surface cleaning nozzle rising from the bottom part 11a. It is supported by a rotary drive 14i1321 and rotated by a rotary drive 14i1321. Rotating layer 17Il! One structure 21 is of a chain type, for example, and has four drive shafts 22 passing through the bottom part 11a.
A chain 25 is wound around the sprocket 23 on the upper end and the parts holder on the sprocket 24 of the stand 18, so that the rotation of the drive shaft 22 is transmitted to the parts holder to the stand 18.

The drive shaft 22 is supported by a bearing 26 on the bottom portion 11a, and is connected to a rotating shaft 29 of a rotor 28 via a coupling 27.

The motor 28 is fixed to the lower surface side of the bottom portion 11a by a bracket 30.

In the center of the cleaning tank 11, a component holder is provided with water (cleaning water) B1 as a cleaning liquid on the outer surface of the small components mounted on the table 18.
A component outer surface cleaning nozzle 31 is provided that spouts out a component external surface cleaning nozzle 31. The component outer surface cleaning nozzle 31 is a columnar type that is erected and fixed above the bottom portion 11a, and sprays cleaning water B1 laterally from the upper side nozzle portion 31a.

In addition, each component holder is placed on the stand 18 to clean the inner surface of the small component A.
A component inner surface cleaning nozzle 32 for spouting water B2 is installed at -. The component inner surface cleaning nozzle 32 has a hollow shaft shape that protrudes above the bottom portion 11a, and has an upwardly directed nozzle portion 32a at its upper end, which spouts cleaning water upward and also serves as a rotating shaft for the table 18. It is configured.

An in-tank cleaning nozzle 33 is provided at the periphery of the bottom portion 11a. This in-tank cleaning nozzle 33 has a header 33b extending along the peripheral wall of the cleaning tank on a columnar base 33a erected on the bottom 11a.
are connected to each other, and nozzle portions 33C are provided at intervals in the circumferential direction, and the cleaning water 83 is spouted diagonally downward on the outer circumferential side of the tank.

A drainage nozzle 34 is provided at the center of the bottom portion 11a to face downward. That is, this drainage nozzle 34 is located at the bottom 11m.
It has a shape with a hole in the center and a nozzle part 34a protruding from the lower end.

Note that the cleaning water inlets 31b, 32b, and 33d of the component external surface cleaning nozzle 31, component internal surface cleaning nozzle 32, and tank internal cleaning nozzle 33 are provided to protrude below the bottom 11a of the cleaning tank 11, respectively.

FIG. 2 shows the configuration of the piping system for supplying and discharging cleaning water.

Water supply In pipe 35 for leading wash water from a water source (not shown)
is branched, and one of the branched water supply branch pipes 35a is cleaned Ig.
11, and the other water supply branch pipe 35b is connected to a storage tank 36a of a cleaning water circulation device 36, respectively. On-off valves 38, 39, and 40 are provided upstream and downstream of the branch point 37, respectively. One water supply branch pipe 35 connected to the cleaning tank 11
a is used for initial water filling of the cleaning tank 11, and the other water supply branch pipe 35 connected to the storage tank 36a
b is for supplying water for storage.

The cleaning liquid regeneration circulation device 36 has a storage tank 36a and a cleaning liquid 1.
It is constituted by a piping system that connects each nozzle 31, 32, 33, and 34 of ff11. That is, the storage tank 36
A cleaning water supply pipe 41 is pulled out from the lower part of a, and a high pressure water supply pump 42, an open 1" valve 43, 44 and a regulating valve 45 are connected to it.
has been established. This wash water supply pipe 41 is branched downstream of the regulating valve 45, and the branch pipes 41a, 41b, 41c@
Parts external cleaning nozzle 3 via adjustment valve 46°47.48
1. Parts inner surface cleaning nozzle 32 and tank interior cleaning nozzle 33
The cleaning water inlets 31b, 32b, and 33d are respectively connected to the cleaning water inlets 31b, 32b, and 33d. A minimum flow pipe 49 is branched from the downstream side of the pressure water supply pump 42 at the wash water inlet 'R41, and this minimum flow pipe 49 is connected to the upper part of the storage tank 36a via a regulating valve 50. In addition, the upper part of the storage tank 36a and cleaning If! 11 through a tank overflow pipe 51.

In addition, a circulation pipe 52 is connected to the nozzle part 34a at the lower end of the drainage nozzle 34, and this is connected to the circulation pump 53 and the on-off valve 54.
．． ll via 55! One side 6 of the I''A unit 56 is connected. The secondary side of the filter 56 is connected to the upper part of the storage tank 36a.

In addition, a drainage pipe 52a having a li1 closing valve 57 is branched from the middle of the circulation pipe 52, and an overflow pipe 58 is connected from the cleaning tank 11 to the storage tank 36'a.
Drainage pipes 60 each having an on-off valve 59 are led from the pipes, and a waste treatment system 61 that integrates these pipes is connected. The outlet of the pipe 58 of the cleaning tank 11 is set at a level slightly lower than the upper surface of the table 18.

Further, vent pipes 62 and 63 are installed in the cleaning tank 11 and the storage tank 36a, respectively.

Next, the effect will be explained.

First, 1M of the water supply main pipe 35 and one water supply branch pipe 35a.
The closing valves 38 and 39 are opened to fill water up to the level of the outlet of the overflow pipe 59 of the cleaning tank 11, and then the on-off valve 39 of the water supply branch pipe 35a is closed.

Next, open the on-off valve 40 of the other water supply branch pipe 35b and fill the wash water storage tank 36a with water up to the level of the outlet of the tank overflow pipe 51.
Close. Next, the lid 13 of the cleaning tank 11 is opened, and each component holder is placed on the CHD cylindrical small parts on which the radioactive cladding is attached on the stand 18, such as the outer filter, inner filter, guide kit top, coupling spud, and strainer. etc. are mounted in an upright state with their axes aligned with the component receiving stand 18, and then 1113 is closed.

The return motor 28 is driven to rotate the plurality of parts receivers 18 at the same time, and the circulation pump 53 and high pressure water supply pump 42 are driven to start parts cleaning. That is, the cleaning water C stored in the cleaning water storage tank 36a is transferred to the cleaning water supply pipe 41 by the action of the high-pressure water supply pump 42.
It is force-fed to the cleaning Wi11 side via. At this time, after the cleaning water is adjusted to a predetermined flow rate by the adjustment valve 45 downstream of the high-pressure water supply pump 42, the flow rate is further adjusted by the adjustment valves 46, 47, and 48 of the branch pipes 41a, 41b, and 41c.
It is supplied to a component outer surface cleaning nozzle 31, a component inner surface cleaning nozzle 32, and an in-tank cleaning nozzle 33.

Then, a predetermined amount of 1ffl of high-pressure cleaning water is applied to each nozzle 31.
．． 32.33 or 1B wash [! IIfl output L in 11, II
The parts receiver a is cleaned from the inside and outside of the small parts A of the CRD mounted on the stand 18 to which radioactive cladding has adhered.

The radiation pressure crud removed from the parts by the high-pressure cleaning waters B and B2 falls to the bottom 11a of the cleaning water tank 11 together with the cleaning waste liquid, and the high-pressure cleaning water B3 jetted from the cleaning nozzle 33 in the tank flows from the drainage nozzle 34 to the circulation piping. 52 and is pumped to a filter 56 by a circulation pump 53. At this time, the on-off valves 57. of the drainage pipes 52a, 60.
59 is in an open state. The pressure-fed washing waste liquid is passed through the filter 85.
Solid contents such as radioactive cladding are separated and removed by a filter element built in 6, and the water is recycled into clean washing water. The regenerated cleaning water is returned to the cleaning water storage tank 36a through the circulation pipe 52, and is repeatedly used as high-pressure cleaning water for cleaning small parts of the CRD. Note that the cleaning water introduced into the cleaning water storage tank 36a in an amount exceeding the specified m is transferred to the cleaning tank 1 via the tank overflow pipe 51.
1 and further refluxed. After cleaning the parts inside the tank,
Temporarily stop the pumps 42 and 53 and replace the parts.
The simulated pumps 52 and 53 are driven.

As described above, after all the parts of the CRD that are subject to periodic inspection have been cleaned and the parts have been removed, the circulation pump 53 continues to forcefully feed the cleaning water to the filter 56 for a while, thereby cleaning the inside of the tank. .

Thereafter, the high-pressure water supply pump 42 and the circulation pump 53 are stopped, and the on-off valve 57 of the drainage pipe 528.60 is stopped.
．． 59 and wash tank 11 and wash water storage tank 36.
The cleaning water in a is discharged and transferred to the waste treatment system 61.

According to the above embodiment, the following effects are achieved.

■ Solid content such as crud is constantly removed from the washing water by the filtration Ps56, and the water is regenerated into a clean state and used repeatedly, so a! The amount of cleaning liquid discharged from the waste animal treatment system 61 can be significantly reduced.

(2) Unlike the conventional method in which the cleaning water in the cleaning tank 11 is replaced after each cleaning, the time required for filling and draining the water is significantly shortened.

■In the cleaning tank 11, a plurality of CRD small parts are housed in the skin, and the cleaning work can be performed simultaneously and remotely, so the time and labor required for cleaning work are greatly reduced, and the plant is movable. It is possible to effectively improve the rate and reduce exposure.

■Since each part is cleaned by washing water that is sprayed on the inside and outside surfaces while rotating, cleaning is performed reliably and quickly.

■ By installing the cleaning nozzle 33 in the tank, the cleaning tank 11
The crud that accumulates inside the tank is reliably discharged, and the inside of the tank is always kept clean.

In the above embodiment, the cleaning tank 1 is used as a radiation shielding means.
Although shielding walls 16 and 17 are provided to cover the outer side of the cleaning tank 11, the present invention is not limited to this, and as shown in FIGS. 2 and 3, the cleaning tank 11
It may also be used as a radiation shielding means by storing and holding the reserved water 64 inside, so that the CHD small parts 8 to be cleaned can be immersed to a sufficient depth. With such a configuration, it is possible to omit the radiation shielding wall. NaJ
3. Since the other configurations are substantially the same as those of the large-wheeled example, corresponding parts in the figures are designated with r:J, which is the same as in FIGS. 1 and 2, and the explanation thereof will be omitted.

Further, the present invention is not limited to the above-mentioned embodiments, but may be constructed by combining both of these IMW4s.

Such a configuration further improves the radiation shielding effect.

Note that hot water at room temperature or higher may be used as the cleaning liquid, and the circulation pump 53 may be disposed on the secondary side of the filter 56.

Of course, various changes can be made, such as installing an ultrasonic cleaner in the cleaning tank 11 or changing the shape and arrangement of the nozzles 31, 32, and 33.

Further, as cleaning parts, in addition to cylindrical parts, coil-shaped parts, box-shaped parts, etc. having inner and outer surfaces can be used.

〔Effect of the invention〕

As described above, according to the parts cleaning device for a control rod drive mechanism according to the present invention, the cleaning liquid is sprayed onto the inner and outer surfaces of the rotating parts to be cleaned. Since the cleaning is performed continuously, the inner and outer surfaces of the control rod drive EGX component parts to which radioactive cladding is attached can be efficiently and reliably cleaned. In addition, the cleaning solution is filtered and circulated to separate and remove solids such as crud, and is always re-washed with clean cleaning water for repeated use. can be significantly reduced.

Furthermore, since the cleaning liquid can be used for a long period of time by being regenerated, the time and labor required for filling and draining the water can be significantly reduced, unlike conventional devices that require the cleaning liquid to be filled in the cleaning tank for each cleaning.

Additionally, multiple small parts can be cleaned simultaneously and remotely, which greatly reduces the time and labor required for cleaning, improving plant availability and reducing radiation exposure for workers. It is extremely effective in achieving this goal.

In addition, according to the configuration in which an in-tank cleaning nozzle is provided, crud, etc. can be discharged from the inside of the cleaning tank more quickly and smoothly.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention; Fig. 2 is a sectional view showing the internal structure of the cleaning tank; Fig. 2 is a system diagram showing the overall structure of the parts cleaning device including piping; and Fig. 3 is a cross-sectional view showing the internal structure of the cleaning tank. FIG. 4 is a sectional view showing another embodiment, FIG. 4 is a system diagram showing the overall configuration of the embodiment shown in FIG. 3, and FIG. 5 is a system diagram showing a conventional example. 1...Cleaning tank, 11a...Bottom, 16.17...
Shield g! (Radiation shielding means), 18...The component holder is a stand,
21... Drive mechanism, 31... Parts outer surface cleaning nozzle,
32...Component inner surface cleaning nozzle, 33...Inside tank cleaning nozzle, 36...Cleaning liquid regeneration and circulation device. Applicant's agent Hisashi Hatano 5g

Claims (1)

[Claims] 1. In a device for cleaning control rod drive mechanism parts having a cylindrical shape or other shape having inner and outer surfaces, the parts are mounted in a cleaning tank equipped with a radiation shielding means and a parts receiver is rotatably driven. a component outer surface cleaning nozzle that sprays a cleaning liquid onto the outer surface of the component on the component holder; and a component inner surface cleaning nozzle that protrudes above the component holder and sprays the cleaning liquid onto the inner surface of the component;
and receiving and filtering the used cleaning liquid from the cleaning tank,
A parts cleaning device for a control rod drive mechanism, comprising a cleaning fluid regeneration and circulation device that supplies clean cleaning fluid to each of the nozzles. 2. The parts cleaning device for a control rod drive mechanism according to claim 1, wherein the cleaning tank is equipped with an in-tank cleaning nozzle that sprays cleaning liquid onto the inner surface of the cleaning tank.