JPS6340583B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crud separation device that uses a magnetic field to separate crud in a fluid, such as nuclear reactor coolant.

The crud separator is installed in the middle of the reactor coolant pipe and in a part of the tank, and is used to separate and remove crud (fine iron oxide particles such as Fe ₂ O ₃ and Fe ₃ O ₄ ).

In general nuclear reactors, fluids such as light water, sodium, carbon dioxide, helium gas, and reactor coolants are used depending on the type of reactor to extract the heat generated in the reactor core.

By the way, many constituent materials such as high-quality steel are used in nuclear reactor pressure vessels, piping, etc., and due to the effects of erosion caused by radioactive thermal energy during reactor operation, the above-mentioned crud is produced as radioactive corrosion products. It is said that a phenomenon occurs in which the particles are generated, mixed into the reactor coolant, and circulated through the pipes. These cruds are extremely small in quantity and depend on the operating history of the reactor and differences in the constituent materials, but the particle size is approximately 1 to 10 micrometers (μm), and the amount gradually increases. It has been observed that there is a tendency to increase. Since these cruds are fine particles, they do not affect normal nuclear reactor operation.

However, as the crud circulates in the reactor cooling system in a suspended state, the crud settles and accumulates in areas where the flow velocity is slow or when the reactor is stopped. Since cladding is a radioactive material composed of CO ⁶⁰ and other elements, it can cause high radiation doses at and around the deposition site, causing exposure during equipment maintenance, etc. It is also said to cause deterioration of materials such as piping materials. Furthermore, it causes a narrowing phenomenon in the pipeline, which causes the pipe to lose its function, and also causes trouble in the functioning of precision equipment such as the reactor core mechanism.

Therefore, it is necessary to remove these cruds efficiently, and it is also required that the treatment after removal be convenient.

The present invention has been made in consideration of the above background,
Focusing on the fact that the cladding is a magnetic material, the objective is to guide the reactor coolant through piping and introduce it into a cylindrical separator, where it is formed along the circumferential and radial directions and rotated. The objective is to efficiently separate and remove crud by applying an alternating magnetic field, thereby improving the integrity of nuclear power generation facilities.

In order to achieve these objectives, the present invention provides a ring-shaped reaction chamber for guiding the reactor coolant, and has different angular velocities on both sides of the reaction chamber in the radial direction on the outside and inside along the circumferential direction. The present invention is characterized in that a plurality of magnets are provided which rotate and move, and the magnets are arranged in a relationship such that adjacent poles in the circumferential direction are different poles.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

In FIGS. 1 and 2, the reference numeral 1 indicates a ring-shaped container. This ring-shaped container 1
The reactor has a structure in which a ring-shaped reaction chamber 2 to which a reactor coolant (for example, light water) is supplied is provided between a true cylindrical outer wall 1a and an inner wall 1b whose axial directions are vertically aligned. At the same time, it is fixed on the support frame 3. The reaction chamber 2 is shielded by a partition wall 4 disposed in the vertical direction, and a reactor coolant is circulated through a fluid inlet 5 and a fluid outlet 6 provided at the upper and lower parts near the partition wall 4. It is connected to the pipes etc. Further, a clad storage section 7 is provided at a position close to the partition wall 4 and at the bottom of the reaction chamber 2. The fluid outlet 6 is communicated with the reaction chamber 2 at a position slightly above the bottom to avoid interference with the clad reservoir 7.

Further, on both sides of the reaction chamber 2 in the radial direction, there are a plurality of magnets (such as permanent magnets) 8A, 8B, 9A, for applying a magnetic field to the crud in the reactor coolant.
9B are arranged along the circumferential direction. These magnets 8
A, 8B, 9A, 9B are the outer support frame 10 and the inner support frame 1, as shown in FIGS. 1 and 2.
1, and each magnet is arranged so that adjacent poles in the same direction are different poles (N pole and S pole), and the outside and inside are the same number at the same angular interval. In the example shown in FIG. 2, the magnet forming one pole has a structure in which a plurality of vertically divided blocks are integrated.

Both the support frames 10 and 11 are mounted on the outer guide rail 12 and the inner guide rail 13.
A plurality of magnets 8 are mounted via a plurality of wheels 14.
The structure is such that A, 8B, 9A, and 9B rotate with the reaction chamber 2 in between. Both support frames 10 and 11 are connected by an angular velocity setting mechanism 15 so that the outer and inner sides of each magnet rotate at different angular velocities.

The angular velocity setting mechanism 15 includes an external gear 16 integrally provided on the outer periphery of the outer support frame 10, a pinion 17 that meshes with the external gear 16, and connection gears 18 and 19 that mesh with the pinion 17. A pinion 20 that meshes with the connecting gear 19, and a pinion 20 that is integrally provided on the inner periphery of the inner support frame 11.
It is composed of an internal gear 21 that meshes with the
The structure shown in the figure is such that the gear ratio is set so that a positional shift in the horizontal rotation direction occurs little by little between the two freely rotatable support frames 10 and 11, thereby creating a difference in angular velocity of 10% or less. The examples are not limited.

Further, a drive mechanism 22 is connected to the angular velocity setting mechanism 15, and each magnet is configured to rotate and move at a different angular velocity. That is, the drive mechanism 22 includes a motor 23 and a drive gear 24 that transmits the rotational force of the motor 23 to the pinion 17, and applies a strong magnetic field to the crud in the reactor coolant, for example, about 10 times per second. It is said to be composed of

The operation of the clad separation device constructed as described above will be explained below.

When the reactor coolant is sent into the reaction chamber 2 from the fluid inlet 5, the floating cladding is pushed near the magnetic poles against the viscosity of the reactor coolant due to the action of the magnetic field formed by each magnet. Try to move to etc.

In this case, since the circumferentially adjacent poles of each magnet are different as shown in Fig. 1, a magnetic field is generated along the circumferential direction, and the clads are magnetically attached to each other in the circumferential direction, as shown in Fig. 3. As shown by C ₁ , it is collected near both side walls 1a, 1b.
1 is rotated and moved at different angular velocities, the alternating magnetic field accompanying the rotation and the case generated when the opposing magnets have different polarities act on any one point in the reaction chamber 2, and at a certain moment In this case, a phenomenon occurs in which the cladding is aligned as shown by C ₁ and C ₂ in FIG. 3B, and when the opposite poles become the same pole, the phenomenon in which the cladding is dispersed and sinks is repeated.

Therefore, in the entire range of the reaction chamber 2, the cladding is moved as shown by arrows ω ₁ and ω ₂ in Figure 3, but due to the viscous resistance of the reactor coolant, the movement of each magnet is After a delay, when the cladding is located between different poles, it is restrained and driven in the direction of the partition wall 4, and when the cladding is located between the same poles, the restraint is released and it sinks due to its own weight, which is repeated. However, it is ultimately guided to the partition wall 4. In addition, during suction, the particles become larger due to the mutual bonding of the clads due to the magnetization of the clads, and during dispersion, the particles repeatedly fall due to their own weight while being accompanied by a diffusion effect. will be collected. Hereinafter, the crud collected in the crud storage section 7 is taken out and processed as appropriate.

Note that the speed of the drive source for rotating each magnet may be controlled separately. Further, each magnet may be an electromagnet (direct current or alternating current) instead of a permanent magnet.

As is clear from these descriptions, according to the present invention, the following effects can be achieved.

If crud is mixed in the reactor coolant, it can be separated and removed in the middle of the circulation path.
The health of nuclear power generation facilities can be improved.

Since a magnetic field is applied to the crud, large grained crud can be efficiently separated and removed.

By setting the poles of circumferentially adjacent magnets to be different and creating a forced shift in angular velocity between the outside and inside, an alternating magnetic field is applied to the entire area of the reaction chamber, and restraint and dispersion are achieved. By repeating this process, the movement of the crud can be promoted and the crud can be collected efficiently.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Figs. 3 A and B explain the action of the magnet. This is a developed diagram. 1...Ring-shaped container, 1a...Outside wall, 1b...
...Inner wall, 2...Reaction chamber, 4...Partition wall, 5...
Fluid inlet, 6...Fluid outlet, 8A, 8B, 9A,
9B... Magnet, 10... Outer support frame, 11... Inner support frame, 15... Angular velocity setting mechanism, 22... Drive mechanism.

Claims (1)

[Claims] 1 In a clad separation device in which a magnetic field is applied to corrosive products contained in a fluid, there is a ring-shaped reaction chamber to which the fluid is supplied, and an outer wall along the circumferential direction on both sides of the reaction chamber in the radial direction. and a plurality of magnets provided so that the inner side and the inner side are rotated at different angular velocities, and the magnets have circumferentially adjacent poles of different poles, and the same number of magnets are arranged at the same angular intervals on the outside and the inside side. A crud separation device characterized by: