JPS58161890A - Reactor structure handling 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 [Technical Field of the Invention] The present invention relates to a reactor internals handling device for handling reactor internals, such as a steam dryer, etc., housed in a nuclear reactor pressure vessel.

[Technical background of the invention and its problems]

Figure Jli1 is a schematic configuration diagram of boiling water reactor equipment, and 1 in the figure is a reactor pressure vessel. The upper cover IA of the reactor pressure vessel 1 is designed to be removable. The reactor pressure vessel 1 is placed on a pressure vessel pedestal 2. The Maku reactor pressure vessel 1 is housed in a reactor containment spring jj. The 8mm upper roof of the reactor containment volume aX is also attached to the removable interior. The reactor containment vessel S is divided into a dry well 3B and a ψ bullet damper 3C. The outer periphery of the reactor containment vessel SO is covered with a shielding wall 4 made of Contarito. The covering wall 4 is formed integrally with the building frame 5, and is connected to the reactor containment volume ll0JIll! ! A large number of compartments d...are forming hair. Various nuclear reactor equipment (not shown) is housed in this compartment 6. A fuel boule 11 and an equipment storage boule 1 are provided above the compartment-0. These two pools r and 8 are divided by pool plugs 9 with attachment/detachment, and there is a dry well jDk above the reactor containment vessel 3.
is forming.

This dry well JD is closed with a removable felt plug 10, and serves as a working truer 11 on the upper surface side. An overhead crane 12 is provided above the work floor 11.

During periodic inspections of such nuclear reactor equipment, the following steps should be taken:
Let's do it. First, there is water t # ft inside the reactor pressure vessel 1.
T o And Fell Plug 109f Overhead Crane 1
Remove the weir with step 2, and remove the upper cover S in the same way.

Remove the IAI and remove the above dry well 3B and reactor well 3.
Fill D with water. After being exposed to radiation in this way, the reactor internal structures in the reactor pressure vessel 1, such as the steam dryer, steam separator, etc., are removed.

The handling of these reactor internals is carried out as shown in FIGS. 3112 to 3. In FIG. 2, 1s is a steam/water separator, for example, and this steam/water separator 13 is radioactive and is always handled submerged in water to protect it from radiation tm. 1svr for the above air/water separation 11
When handling lK, the reactor internals handling equipment 14 separates steam and water @1
31 and hang it with the overhead crane 12 of the reactor internal structure handling device 149f.

By the way, radioactive materials such as crud are mixed in the water inside the reactor pressure vessel 1, and if the entire reactor internals handling device 14 is submerged in water during the operation of the steam separator 13, the reactor internals will be handled. Because radioactive materials would adhere to the equipment 14, the reactor internal structure handling equipment 14 had to be decontaminated after the work was completed. Further, if the hook Jj of the overhead crane 12 is submerged in water, radioactive substances will also adhere to the hook 15. If you don't do this, hook J
When the workpiece is lifted, water containing radioactive materials will be dripped onto the worker on the work turret 11, which is undesirable as it will increase the worker's radiation exposure. For this reason, decontamination of the footer IJ would be carried out, but since the overhead crane IJ is frequently used during periodic inspections, decontamination work would unnecessarily lengthen the period required for periodic inspections. Therefore, the steam and water separator JJij was handled in such a way that the hook 151 was not submerged in water.

First, as shown in FIG. 2, the water level is lowered to the extent that radiation from the steam separator II can be shielded. Next, the reactor internal structure handling device 211 is suspended by the overhead crane 12 and the steam/water separation @73Wl- is held. And the water level t hook 1
After the water separator 1B'lf is gradually raised with a Sat that does not submerge the water separator 1B'lf, the ceiling crane 12 lifts the water separator 1B'lf to a level where the water separator IJ is not exposed above the water surface. [Repeatedly, as shown in the JI3 figure, the water level is raised to the extent that the steam separator 13 can be moved underwater to the equipment storage boule 8, and the water separator 13 [moved underwater to the equipment storage pool 1]] let In this way, the method of raising the water level by preventing the hook Ilf from being submerged and by preventing the steam separator 139f from being exposed above the water surface had a problem that caused a long period of time for periodic inspections.

[Purpose of the invention]

The object of the present invention is to provide a reactor internal structure that can be worked on in a short time without submerging the entire equipment as the water level rises and falls, without exposing the activated reactor internals from the water surface. Handling equipment [to be provided]

[Summary of the invention]

In the reactor internal structure handling device according to the present invention, even if the reactor internal structure under water is locked by providing a locking mechanism on a one-body extension rod that is suspended by a crane, the reactor internals will not be left unattended. To prevent the extension rod from being submerged in water, install a water level detection mechanism on the extension rod to detect the water level, and install a control circuit on the extension rod to detect the water level.
Even if the water level changes due to the signal, the reactor internals are kept within a certain range @
1) The crane is controlled by the control circuit so as to prevent the entire main body from being submerged in water as well as the chair held below the water surface. One explanation of the embodiment, 0, the same as before O is the same code. 101 in the j14 figure is the main body,
This main body 1 #1 is formed into a cross shape by joining with steel plate tS bales. A holding part 101 is provided on the upper side of the main body 1-10, and a holding part 101 is attached to the overhead crane JJO hook 15 with a holding part 8101. An extension rod 101 is attached to the bottom surface of the main body 11110. A locking mechanism 101 is provided at the bottom of the extension rod 7610, and the extension rod 103 is a locking mechanism. U” is O in water
Reactor internals, for example, steam/water separation 1) The length is set so that the main body 101 will not be submerged in water even if J 3 is locked.
The locking mechanism opening is the locking claw 104. The locking pawl 104 is made of JIS wire and is configured to be operated from above the work floor 1 via a wire 1019g to engage and disengage the steam/water separator 13f using a well-known mechanism. In addition, the above extension pipe 10
A water level detection gate structure U is provided at the intermediate portion of the water level.

This water level detection mechanism fag is composed of an upper limit level switch 10F and a lower limit level switch 108, both of which are configured to output a signal when the water level changes from between bell switches J#F and J##. The main body 101 is provided with a control circuit 109, and this control circuit 1
-# controls the overhead crane 12 (D operating circuit 11#) according to the signal from the water level detection mechanism leg to cause the overhead crane 12' to perform lifting/hanging operations so that the water surface is located between the level switches 101 and 1011. control to do so.

The control circuit 10# is configured as shown in the 6th WA, and in the figure, 10rm is a movable contact of the upper limit level switch 101, and o It, Jg# is a movable contact of the lower limit level switch 1#8. , these both rotating contacts 10
1 and I## are connected in parallel to the operating circuit 110 of the overhead crane 12, and the transmitters 111 and 111 are also connected in parallel. The above contact jar, 108
Each relay 773. JJ4 is connected in series with this relay JJIFtla point 113.

The contact 111 is connected in parallel to the operating circuit 110, and the contact 114 of the relay 114 is connected to the operating circuit 110, and the contact 114 of the relay 114 is connected to the operating circuit 110. 0 is connected in parallel to 0, and contact 114 of relay 114 is connected to contact JJJ.
B and relay 71g are connected in series. Similarly, contact 113B of relay 111 and relay 11- are connected in series to contact 114. Maku, the above contact point 113
For humans, relay 1150111 point 115m, contact 114
A relay 1110 contact 116 is connected in parallel to the system to form a self-holding circuit.A relay 1150 contact 115B is connected in series to the transmitter 111, and a contact 116B of the relay 116 is connected in parallel to the transmitter 111. The operation of the control circuit 10m connected in series to the control circuit 112 will be explained. II point JOJI
A is a contact of the lower limit level switch 10M, which closes when the water level becomes lower than the lower limit level switch 101. When the water level reaches 0, the relay 114 operates and the contact 114A closes, so the relay 116 operates and the contact 116B closes. 0, the transmitter @111 operates and transmits a crane lowering signal to the operating circuit 110. At this time, contact 116A of relay 11#
is closed and forms a self-holding circuit, so even if the water surface vibrates, the transmitter 111 continues to operate, and does not move minutely according to the wave motion of the water surface.Then, the main body 101 descends and reaches the upper limit level. 1010 When the contact 107A is closed, the relay 113 operates to open the contact 113B and stop the operation of the transmitter 112, thereby stopping the descending operation of the overhead crane 12.In addition, the water level rises and the upper limit level switch 161 is activated. Even when the water level rises above, the same operation and transmission @J J
Send the crane lift signal from 1. In this way, the control circuit 1# in the evening, the water surface is always above both
0, which operates between or and xoa
The structure described above has the following effects.

First, since the overhead crane 12 moves up and down in accordance with the rise and fall of the water surface, the water surface is always located between the two above-mentioned bell switches JOF and 161, and is kept below the water surface with air and moisture -@I IqIC. The height of the main body 1#1 can be adjusted to prevent the body from being submerged in water. Therefore, the steam/water separator 111 can be easily handled in a short time.

Since the tftsft substance adheres only to the lower part of the extension rod 108, the decontamination work can be completed easily and in a short time.Furthermore, the control circuit 1
At 09, the self-holding rotating crane 12 can smoothly raise and lower the overhead crane 11t without making small movements.

Note that the present invention is not limited to the above embodiment.

For example, the signals from the transmitters 111, 111 are not limited to being transmitted to the operating circuit 1.10 of the overhead crane 12 by wire, but may also be transmitted wirelessly.-1 [Effects of the Invention] This invention The reactor internals handling device according to the invention prevents the entire device from being submerged in water even if a locking mechanism is provided on the extension rod extending below the main body suspended by a crane to lock the reactor internals below the water surface. In order to prevent this from occurring, a water level detection mechanism is generally placed on the extension rod to detect the water level, and a control circuit is installed to keep the inner reactor structures below the water surface within a certain range based on the signal from the water level detection mechanism. At the same time, the crane is controlled by the control circuit to prevent the entire structure from being submerged in water. Therefore, the main body can be raised and lowered while shielding radiation tm from the reactor internals and preventing the equipment body from being submerged in water.
Handling of reactor internals [Can be done easily and in a short time. In addition, the decontamination work of the O-system after work can be carried out easily and in a short time, which is very effective.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of nuclear power generation equipment O, and Figures 2 and 3 are explanatory diagrams showing conventional reactor internal structure handling work.
Figure 14 to JIs diagrams are diagrams showing one embodiment of the present invention.
FIG. 4 is an external perspective view, and FIG. 5 is a circuit diagram showing the control circuit 109. Extension rod, 1114... Locking claw, 105... Wire, L
L! ... Water level detection mechanism, 101 ... Upper limit level switch, 10 [ ... Lower limit level switch, 109 ... Control circuit, 113-115 ... Relay, 111-112
···Transmitter.

Claims (3)

[Claims] (1) A main body suspended by a crane from above the reactor pressure vessel, an extension rod extending downward from the main body, and a rod installed at the bottom of the extension rod that is submerged to a certain depth below the water surface. a locking mechanism that locks the reactor internal structure, a water level detection mechanism that is attached to the extension rod and detects the water level of the water surface;
A method for handling reactor internal structures characterized by comprising a control circuit that controls the crane to maintain the reactor internals within a certain depth range based on a signal from the water level detection mechanism and to prevent the main body from being submerged in water. device 0 (2) The control circuit consists of a relay and a transmitter, and the O signal from the transmitter causes the crane to move up and down, and also forms a self-holding circuit to prevent minute movements caused by waves on the water surface. The reactor internals handling apparatus described in the claim [111(1)l] is characterized in that it is futile. (3) The water level detection mechanism comprises an upper limit level switch and a lower limit level switch, and the water surface is located between the bell slides. ) Reactor internal structure handling equipment described in section 2.