JPS58102194A - Magnetic filter for reactor coolant - 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 The present invention relates primarily to improvements in electromagnetic filters used as coolants in light water-cooled nuclear reactors.

Corrosion products (hereinafter referred to as chloride) from piping equipment in light water nuclear power plants.

The circulating coolant flows into the reactor core where it becomes radioactive. This radioactive cladding.

- It is dispersed into the coolant system and redeposited on the walls of equipment piping, which accounts for most of the radiation exposure of power plant workers.

In general, cladding has a small grain size and is difficult to remove with a normal mechanical filter, but electromagnetic filters that utilize the magnetism of kraft are increasingly being recognized as effective.

The electromagnetic filter has a magnetic field formed inside the body.

A coolant containing cladding is introduced to magnetize the cladding, and the cladding is collected using a ferromagnetic filter material (steel balls, metal mesh, metal fibers, etc.) filled in the shell. Because it is radioactive, it poses the following problems.

In other words, if the filtration of the coolant is continued, the water flow pressure loss will increase and zero inspection and maintenance work will be required.

(1) It is difficult to remove the filter element.

(2) Filter element breaks due to repeated cleaning]
(3) Due to the capture of damaged filter elements.

Requires post-filter.

All of these are intended to prevent radiation exposure of workers performing these tasks.

The present invention has been made in view of the above-mentioned problems, and includes placing the ferromagnetic filter material to be filled into the barrel in a non-magnetic porous container, and attaching a handle for handling the container to the porous container, thereby dispersing the damaged filter material. It is an object of the present invention to provide an electromagnetic filter that prevents electromagnetic interference from occurring and facilitates remote control using a manipulator or the like.

The present invention will be explained below based on the illustrated embodiments. □ In FIG. 1, a magnetic pole plate 5 is provided in the body 3 having the outlet 1, and a return frame 9 provided with the electromagnetic coil 7 outside the body 3 is magnetically connected to the magnetic pole plate 5. are doing.

The upper lid 13 having the inlet 11 is connected to the body 3 by flange connection.
The inlet 11 is fixed to the open end of the reactor 9 and communicates with the reactor coolant circulation system via a pipe (not shown).

A non-magnetic porous container 15 is provided between the magnetic pole plates 50 with its outer peripheral surface in contact with the inner surface of the body 3.

FIG. 2 is a perspective view of the porous container 15, and FIG. 3 is a perspective view of the porous container 1.
As shown in Figure 1, a handle 17 for handling and operation is fixed to the upper part, and the inside is filled with a filter material 19, which will be described later.

The filter material 19 is a ferromagnetic metal mesh of about 10 to 200 meshes, but may also be metal fiber.

The pore diameter of the container 15 is smaller than the wire diameter of the filter material 19, and is about 10 to 1.000 microns. These °
The range of the hole size can be selected by examining the size of the cladding in the coolant, and when processing liquids other than coolant.

Appropriate selection may be made taking into consideration the size of the object to be collected.

Further, the material of the porous volume $1115 is 8U8304, an austenitic stainless steel, in consideration of corrosion resistance, but 3U8316 is also acceptable.

In the above configuration, a part of the coolant flows into the shell 3 from the inlet 11 during operation of the nuclear reactor.

Entering the magnetic field formed by the magnetic pole plate 5, the cladding in the coolant is magnetized.

The coolant enters the perforated container 15 and is captured by the filter material 19, which is also magnetized. The coolant from which the cladding has been removed comes out from the outlet l.

The coolant is returned to a coolant circulation system (not shown).

Next, to explain the electromagnetic filter inspection work, first, when the operation of the nuclear reactor is stopped and a remote valve (not shown) is operated, the coolant in the shell 3 is discharged.

Next, the upper cover 13 is removed using a remote control manipulator or the like, and the upper magnetic pole plate 5 is removed. Furthermore, a porous container 15
The porous container 15 is taken out by the handle 17, and the filling material 19 is taken out and inspected in an appropriate facility. Please note that the reassembly number is 3. This is done by reversing the above procedure.

According to the embodiment described above, pieces of the T-cofilter material 19 that are damaged due to corrosion or the like remain in the porous container 15;
In addition to being able to prevent its dissipation, the fine filter material 19 can be handled while being placed inside the porous container 15.
It is possible to significantly reduce the amount of radiation exposure during cleaning, inspection, etc.

In the above embodiment, one porous container 15 was used, but two or more porous containers 115 may be stacked as shown in FIGS. 4 and 5.

The roughness of the filter materials 119a and 119b filled therein may be changed. That is, the roughness of the fill material 119m on the inlet side is set to be relatively large and 0.

The filter material 119b on the outlet side is reduced by /lX.

As a result, the crud is evenly distributed and captured in the many porous containers 116, and the increase in pressure loss is low.
It has the effect of high filtration rate.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is an overall view of an embodiment of the present invention, Fig. 2 is a perspective view showing the main parts of the embodiment, Fig. 3 is a sectional view, and Fig. 4 is a diagram showing the embodiment of the invention. A perspective view showing an example of modification of the main part of the example, FIG.
FIG. 1... Outlet, 3... Body, 5... Magnetic pole plate, 7...
・Electromagnetic coil, 9...Return plate, 11...
Inflow port, 13... Upper lid, 15... Porous container, 17.
...Handle, 19...Filter material

Claims (1)

[Claims] A cylinder defining a flow space for the liquid to be treated, magnetic pole plates provided on the inlet side and outlet side of the synchronization, a non-magnetic porous container installed in the cylinder between the magnetic pole plates, and the same. It has a ferromagnetic filter material filled in a porous container and a lid that is removably attached to one end of the body and has a flow port for the liquid to be treated, and the porous container is provided with a handle for handling. Electromagnetic filter for nuclear reactor coolant.