JPS6338196A - Fast breeder reactor stop device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reactor shutdown device for a fast breeder reactor (FBI"t).

[Conventional technology]

FIG. 4 shows a longitudinal sectional view of the fast breeder reactor shutdown device.

1 is a control rod that houses an assembly of absorber elements inside, and by inserting it downward, the reactor can be stopped. 2 is a control rod guide tube, and 3 is a trumpet tube.

This reactor shutdown device is of a self-operating type, and is capable of reducing the magnetic force of the latch magnet 16 using the temperature-sensitive alloy 4 and disconnecting the control rod 1.

Reference numeral 9 denotes a drive shaft which is driven up and down to adjust the position of the control rod 1 by a drive mechanism (not shown) attached to its upper part.

FIG. 5 is a partially enlarged view of FIG. 4. A magnet coil 5 is attached to the iron core 6 attached to the lower end of the WjA moving shaft 9 to constitute a magnet portion 15, and the magnet I.
It has a structure in which the armature 7 is attracted by the portion 15. The armature 7 sandwiches a spacer 8 made of a non-magnetic material, and the rst alloy 4 is attached to the outer periphery of the spacer 8. The temperature-sensitive metal 4 is an alloy of nickel and iron, and is a strong magnetic material at relatively low temperatures, but has the property of losing its magnetism when raised to a certain W degree. Therefore, at relatively low temperatures, when current is passed through the magnet coil 5, an annular magnetic field is formed connecting (iron core 6) - (armature 7) - (temperature-sensitive alloy 4), and the armature 7 is attracted to the iron core 6, but the temperature-sensitive When the temperature of the alloy 4 reaches a certain temperature, the temperature-sensitive alloy 4 becomes non-magnetic and blocks the magnetic field, so it loses its adsorption force, and the armature 7 and the iron core 6
It separates from the body and is inserted due to its own weight. This self-insertion characteristic is extremely important in ensuring the safety of a nuclear reactor, but an important required function is that the device be inserted within a specified time after being disconnected.

[Problem that the invention attempts to solve]

However, in this type of reactor shutdown device, the insertion force is only due to its own weight, and even if it is possible to disconnect, especially in the event of an earthquake accompanied by vertical motion, there may be a delay in the insertion time, so measures are needed to shorten the insertion time. It had been.

The present invention has been made in view of the above-mentioned circumstances, and aims to provide a fast breeder reactor shutdown device incorporating an accelerator so that control rods can be inserted within a specified time even in the event of an earthquake accompanied by vertical motion. .

[Means for solving problems]

It incorporates an acceleration mechanism that pushes the control rod downward as soon as it loses its suction force. Generally, a piston effect due to a spring or pressure is used, but since these are force storage types, they increase the load normally applied to the magnet section, which is not preferable.

Therefore, an electromagnetic acceleration mechanism is installed that generates insertion force at the same time as the magnetic field of the magnet part is interrupted. Therefore, in the fast breeder reactor shutdown device of the present invention, a temperature-sensitive alloy is disposed outside the control rod guide tube, and the armature attached to the upper part of the control rod is inserted into the axis of the temperature-sensitive alloy, and the armature is extended to the lower end of the drive shaft. A magnet part consisting of an iron core and a magnet coil attached to the core is inserted from above, and the control rod is separated together with the armature due to the magnetic properties of the temperature-sensitive alloy. A linear coil is wound around an iron core that is installed upright in the hole of the acceleration head and connected to the drive shaft, and a nearmorph stator is inserted into the core, and the linear coil is activated at the same time as the control rod is disconnected. Connect as shown.

[For production]

Even in the event of a vertical earthquake, the electromagnetic acceleration mechanism activates at the same time as the magnet's magnetic field is cut off, applying downward force to the control rod, so insertion begins immediately. At the same time, the control rods are given an initial velocity, which reduces insertion time.

〔Example〕

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a partial vertical cross-sectional view showing one embodiment of the fast breeder reactor shutdown device of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG.
The figure is a wiring diagram of an embodiment of the fast breeder reactor shutdown device of the present invention.

An acceleration head 10 is attached to the armature 7 on the upper part of the control rod 1, and a linear motor stator 14 is attached above the magnet part 15 on the drive shaft 9 side. This is done by fixing multiple groups of iron cores 11, which are laminated with comb-shaped slots, radially around the shaft with the slots on the outside.
A plurality of linear coils 12 are wound in three stages in one group around the slot ν1, and these are connected to form a three-phase cylindrical linear motor. Reference numeral 13 denotes a protective tube, which is made of a non-magnetic, non-conductive material such as ceramics or thin non-magnetic stainless steel in order to reduce eddy current loss.

FIG. 3 is a diagram schematically showing the connection between the magnet coil 5 and the linear coil 12. DC and AC are both i7! Indicates a current power source and an alternating current power source, where T is a transformer, CT is a current transformer, RY is a relay, and MG is a switch. Also, C is capacitance.

Incidentally, the linear coil 12 in FIG. 1 is connected to a three-phase AC power source. Further, the magnetic screw 1 and the coil 5 perform constant current control using a DC power source, and an AC constant voltage source is superimposed on this DC circuit.

When the magnetic field formed by the magnet coil 5 is interrupted,
Since the impedance decreases, the i of the superimposed alternating current
H+fE increases. CT detected this, and RY, MG
When the linear coil 12 is energized, a traveling magnetic field is generated, and the magnetic flux passes through the radially arranged iron core and interlinks with the accelerating head 10 to generate an eddy current in the accelerating head 10, and the thrust generated by this causes the above-mentioned acceleration. Push down the head 10. As a result, the acceleration head 10 is pushed downward at the same time as the magnet coil 5 is cut off, so that it can be disconnected even in the case of a vertical earthquake, and accelerated insertion can be performed.

Note that the acceleration force depends on the characteristics of the linear coil 12 and the supplied 3
Since it is determined by the phase AC power supply and the material of the acceleration head 10, these can be selected according to the required conditions.

〔Effect of the invention〕

According to the fast breeder reactor shutdown device of the present invention described in detail above, the magnetic field formed by the magnet coil is interrupted, and at the same time, the thrust force generated by the linear coil due to the principle of the linear motor pushes the accelerating head downward. Even in the event of an earthquake accompanied by vertical motion, it is possible to disconnect and perform accelerated insertion, making it possible to shorten the insertion time.

[Brief explanation of drawings]

FIG. 1 is a partial vertical cross-sectional view showing one embodiment of the fast breeder reactor shutdown device of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG.
The figure is a wiring diagram of an embodiment of the fast breeder reactor shutdown device of the present invention.
FIG. 4 is a longitudinal sectional view of a conventional rapid growth arrest device, and FIG. 5 is a partially enlarged view of FIG. 4. 1. Control rod, 2. Control rod guide tube, 3. Trumpet tube, 4.
Temperature-sensitive alloy, 5・Magnetic coil, 6.11・Iron core,
7 Armature, 8 Spacer, 9 Drive shaft, 10 Acceleration head, 1
2 ・Linear coil, 13 Protection tube, 14 ・Linear morph stator,

Claims (1)

[Claims] A temperature-sensitive alloy is placed on the outside of the control rod guide tube, and an armature placed at the top of the control rod is inserted into the axis of the temperature-sensitive alloy. A hollow accelerating head is installed above the armature, and a hollow accelerating head is installed in the hole of the accelerating head. A fast breeder reactor shutdown characterized in that a linear motor stator having a linear coil wound thereon is inserted into an iron core which is erected above the magnet section and connected to the drive shaft, and the linear coil is wired to operate at the same time as the control rod is disconnected. Device.