JPS58215585A - Reactor control device - 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 to a control device for a nuclear reactor, and particularly to a control device for a fast breeder reactor that can be well controlled even during a vertical earthquake.

A conventional example of a fast intensifier will be described below with reference to FIG.

The main container 1 is suspended from a fixed plaque 3 fixed to a building 2. A core support structure 4 fixed below inside the main vessel 1 fixes a core 6 surrounded by a blanket 5 at its center.

7 is a coolant liquid sodium, which is present in the main container 1. A rotary plug 8 is supported around the fixed plug 3, and a large number of control rod drive mechanisms 9 are mounted thereon. 10 is a neutron absorbing material made of boron karate. t
+l+ control rod, the upper end of which is suspended from the control rod 5 drive rock structure 9 and located above the reactor core 6, and the lower end located inside the reactor core 6. To control the reactivity of the reactor core 6 during operation of the nuclear reactor, the degree of insertion of the control rods 10 into the reactor core 6 is adjusted by moving the control rods 10 up and down using the control rod drive mechanism 9.

In normal operating conditions, the reactivity is controlled relatively slowly, and sufficient followability can be ensured by adjusting the vertical position IM of the control rod IO by the control rod drive mechanism 9. but,
When the rotating plug 8 and the reactor core 6 move up and down at a frequency of 6?1 when the formation is in the ground, the vertical displacement is large, and if the control rod drive mechanism 9 does not have sufficient drive followability, the control rods 10 will move into the core 6 more often. Is the reactivity of VC suppressed when inserted? When the control rods 10 move to withdraw from the core 6, the reactivity is increased, and as a result, the reactivity is approximately 1'ft 1ijj,
The reaction of the reactor core 6 may become irregular.

An object of the present invention is to provide a nuclear reactor control device in which the reactivity of the reactor core does not change much even when relative displacement between the reactor core and control rods occurs due to an earthquake or the like.

The present invention uses a set of control rods that are inserted from below and above the core, and by adjusting the spacing between them,
K? I5 control, even if a relative displacement occurs between the control rod and the reactor core, the total amount of neutron absorbing material inserted into the reactor core does not change, thus reducing changes in the reactivity of the reactor core. be.

An embodiment of the present invention is shown in FIG. The upper end of the cylinder 11 that partially and completely forms the control rod 10 is fixed to the control rod drive mechanism 9,
The lower part is inserted through the core 6 and the blanket 5 into a lower guide tube 12 installed in a hole placed on the core support structure 4.

A cylindrical upper control rod 13 is fixed inside the cylinder 11, its upper end is located above the blanket 5, and its lower end is fixed even if the control rod 10 and the reactor core 6 are displaced in the direction of separation due to an earthquake '4. It is arranged so that it is always located within the reactor core 6. The rod 14, which is moved up and down by the control rod drive mechanism 9, is connected to the cylinder 11.
The lower control rod 15 is fixed to the lower end of the upper control rod 13 by passing through the center of the upper control rod 13. The lower control rod 15 has its upper end located above the furnace below the lower end of the upper control rod 13.
6f, and the lower end is always positioned below the core 6f. In the above configuration, when the rod 14 is pulled by the control rod assembly m mechanism 9, the distance between the upper control rod 13 and the lower control rod 15 becomes smaller, and as a result, the reaction of the reactor core 6 is suppressed, and the rod 14 is pushed down. When the reactor is turned on, the reaction in the reactor core 6 is controlled for one month.

In addition, the rotating Prada 8 and reactor core 6 may be damaged due to downward movements such as earthquakes.
Since the relative displacement of , that is, the total amount of insertion of the control rods 10 into the core 6 does not change, the change in the reactivity of the core 6 is small.

FIG. 3 shows another embodiment of the present invention. In this embodiment, the lower control rod 15 is fixed to the lower end of the cylinder 11.
The upper control rod 13 is fixed to the rod 14, and even in the event of an earthquake, the upper end of the upper control rod 13 is always above the reactor core 6, and the lower end of the lower control rod 15 is always below the reactor core 6. The lower end of the lower control rod 13 and the upper end of the lower control rod 15 are positioned within the reactor core 6. Reaction control of the reactor core 6 during normal operation is performed by moving the rods 14 up and down using the control rod drive mechanism 9 and changing the distance between the upper control rod 13 and the -L section control rod 15 within the reactor core 6. Unlike the case in FIG. 2, raising the rod 14 adds reactivity, and lowering it suppresses it. As in the case of FIG. 2, changes in the reactivity of the core 6 due to vertical seismic motion are small. In this embodiment, even if the upper control rod 13 accidentally falls, the upper end of the lower control rod 15 will break. Because of the water, it is impossible to prevent the degree of reaction from increasing.

Note that if the vertical position of the tube 11 is fully adjustable,
It is possible to completely burn different parts in one direction above the core 6.

As described above, according to the present invention, even if a relative displacement occurs in the speed between the control rods and the reactor core, the total amount of neutron absorbing material inserted into the reactor core does not change much. becomes less.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional example, FIG. 2 is a vertical cross-sectional view of one embodiment of the present invention, and FIG. 3 is a vertical cross-sectional view of another embodiment of the present invention. 6...Reactor core, 9...Control rod assembly! ll71 mechanism, 10
...Control rod, 11...Cylinder, 13...Dobe ftjI
1, 14, 15, 1st section, 2nd section, 3rd section

Claims (1)

[Claims] 1. Insert the control rod into the reactor core, and adjust the degree of insertion to control rod drive IJ.
t) reactor core reaction f by changing by J mechanism
lflk In a nuclear reactor control system that adjusts the control rods, the control rods are divided into two in the longitudinal direction, both of which are fixed to the side one-rod drive aJ mechanism, and the control rods are inserted into the reactor core from both ends and a portion is exposed to the outside. 1. A control device for a nuclear reactor, characterized in that the control rods are inserted so as to face each other, and the spacing of the control rods in the reactor core can be changed by the control rod drive mechanism. 2. In claim 1y4, the lower control n-t fixed to the control rod drive mechanism is arranged so that its upper end is inside the core and its one end is outside the core, and the control rod drive mechanism moves the lower control The ten-part system side j stick fixed in the mourning that is moved? A nuclear reactor control device ia' characterized in that it is arranged such that its lower end is inside the reactor core and its upper end is outside the core.