JPH03289598A - Movable in-core measuring device - Google Patents

Abstract

PURPOSE:To enable repairing and inspection without shutting down a nuclear reactor by providing a cylindrical flange being inserted into and fastened to a penetration hole connected to a nuclear reactor building, and a sealing member in the flange and also containing and fastened to a wall of containment vessel. CONSTITUTION:When an abnormality in a nuclear reactors is detected, a motor 16 is actuated and rotational driving force is transferred to a bevel gear 14 via a speed reduction mechanism 15 and therewith, by rotation of a guide screw 13, a valve cutter 12 for shutting off moves down to cut off all of guide tubes 8 for TIP insertion. After the cutting off, the motor 16 is stopped and the valve cutter 12 for shutting off becomes a condition that is shown by the figure. When the valve cutter 12 for shutting off, cuts off the guide tubes 8 for TIP insertion. The cutter 12 moves down as contacting face to face of a flange 7 for shutting off and a sealing member 6 in order to shut off a hole of the guide tubes 8 for TIP insertion. Accordingly, inspection of repairing of a pulling device 17 can be conducted without shutting down the nuclear reactor.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is directed to a mobile in-core instrumentation system (Tra
vering IncoreProve TI
(referred to as P).

(Prior Art) Nuclear reactors have a double or triple sealed wall structure to prevent radioactivity inside the core from leaking outside. For this reason, the reactor core (reactor pressure vessel) is constructed of at least a thick concrete wall and is isolated from the outside.

In order to control a nuclear reactor, it is necessary to guide cables for various control equipment from the reactor building, through the walls of the containment vessel and the pressure vessel, and into the pressure vessel. A TIP flange is used for this penetrating portion of the containment vessel wall, and this TIP
Various sealing members are used to prevent radioactivity from leaking into and outside the reactor building from the flange.

TIP (Traveling IncorePro
ve (hereinafter referred to as TIP) is a mobile in-core measuring instrument that consists of a driving cable and a single detection device with a detection section at the tip of the cable, and is used to check the operating status inside the reactor (reactor output). Unlike the measuring instruments that are always installed inside the reactor, there is a permanently installed measuring instrument that measures the reactor output when necessary, that is, a local power range monitor (Local Power Range Monitor).
or (hereinafter referred to as LPRM) is used for calibration of detected values.

In order to insert this TIP into the reactor core along the LPRM installed in the reactor core, each LPRM is provided with a guide tube for TIP insertion. An indexing device is provided within the containment vessel to select which of the guide tubes to insert the TIP into.

(Problems to be Solved by the Invention) The indexing device is located in the storage container because the current TIP flange is structured to allow only one guide tube for TIP insertion to pass therethrough. Therefore, if the indexing device becomes defective, it cannot be repaired while the reactor remains in operation. In other words, if repairs are carried out while the reactor is still in operation, workers may be contaminated with radioactivity, which is undesirable.

Therefore, when inspecting or repairing the indexing device, even if it is relatively easy, it is necessary to shut down the reactor, and when restarting the reactor, the inside of the containment vessel must be removed. Since it is necessary to check the radioactivity status of the nuclear reactor, it will take time to restart the reactor.

The present invention makes it possible to inspect or repair the indexing device in an area with little radioactive contamination without stopping the reactor even while the reactor is in operation, which reduces the time it takes to shut down and restart the reactor. The purpose of the present invention is to provide a mobile in-core instrumentation device that can save time.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides a method in which a through hole communicating with the reactor building is formed in a part of the containment vessel that surrounds the entire reactor pressure vessel. a cylindrical flange that is inserted and fixed into the through hole, and a seal that is fixed inside the containment vessel so as to be in contact with the flange and against the wall of the containment vessel, and has a plurality of guide tube insertion holes. a blocking flange which is inserted into the inside of the containment vessel and is inserted and fixed within the flange at a predetermined interval from the sealing member, and has a plurality of guide tube insertion holes; A plurality of movable in-core measuring instruments (TIPs) are inserted through the guide tube insertion holes of the shutoff flange and the seal member, respectively, and are inserted along the local power range monitor installed in the reactor. and a TIP insertion guide tube arranged in the reactor building outside the containment vessel, and selecting whether to insert the mobile in-core measuring instrument into any one of the TIP insertion guide tubes. an indexing device; an indexing device on the inside of the containment vessel of the flange;
It is movable in a direction perpendicular to the P insertion guide tube and can slide into contact between the sealing member and the shutoff flange, so that when an abnormality occurs in the reactor, radioactivity leaks to the outside. In order to prevent this, the present invention is equipped with a shutoff valve cutter for cutting each of the TIP insertion guide tubes.

(Function) According to the present invention, when an abnormality occurs in the nuclear reactor, the shutoff valve cutter is driven between the shutoff flange and the seal member while slidingly contacting them, and the TIP insertion guide tube is cut. As a result, the hole of the TIP insertion guide tube is closed.

Therefore, even while the reactor is operating, the indexing device can be inspected or repaired in an area with little radioactive contamination without stopping the reactor, reducing the time required to shut down and restart the reactor. Can be shortened.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, in which a reactor pressure vessel (core) 1 made of concrete (not shown)
The entire area is surrounded by a reactor containment vessel 2, and on the wall of this reactor containment vessel 2, cables for various control equipment and the like are connected from the reactor building 3 to the containment vessel 2 and the pressure vessel to control the reactor. A through hole 4 is formed in order to lead the pressure vessel 1 through the wall 1, and a TIP flange 5, a sealing member 6, and a blocking flange 7 are inserted into the through hole 4 as shown in FIGS. 2 and 3. , TIP insertion guide tube 8, shutoff valve cutter 12, guide screw 13, bevel gear 14,
A deceleration mechanism 15, a motor 16, an indexing device 17, and a cutter supporting structure 18 are provided.

That is, the TIP flange 5 has a cylindrical shape and is inserted and fixed into the through hole 4 of the containment vessel 2, and a cutter insertion hole 9 is formed in a part of the wall surface so that a cutoff valve cutter 12, which will be described later, is inserted therein. has been done. The sealing member 6 is made of, for example, a Teflon sealing material, is fixed inside the containment vessel 2, within the flange 5 and in contact with the wall of the containment vessel 2, and has a plurality of guide tube insertion holes (not shown). ing.

The blocking flange 7 is inserted into and fixed to the seal member 6 at a predetermined distance within the flange 5 inside the containment vessel 2, and has a plurality of guide tube insertion holes (not shown). The TIP insertion guide tube 8 is inserted into the guide tube insertion holes of the cutoff flange 7 and the seal member 6, which are inserted and fixed in the flange 5, and is inserted into the local power range monitor 10 (the first one) installed in the reactor. It is for inserting a mobile in-core measuring instrument (TIP) along the line (Figure 1), and is equipped with a plurality of these (10 in this case).

A cutter supporting structure 18 is fixed to the TIP flange 5 located inside the containment vessel 2, and a motor 16 and a speed reduction mechanism 15 that transmits the power thereof are supported and fixed thereto. The output shaft of this reduction mechanism 15 has a bevel gear 1
4 is fixed, and a guide screw (lead screw) 13 is rotatably supported between the bevel gear 14 and the flange 5 in a direction perpendicular to each of the TIP insertion guide tubes. There is. That is, one end of the guide screw 13 is rotatably supported by the flange 5, and the other end of the guide screw 13 is connected to the bevel gear 14. When the guide screw 13 rotates, the shutoff valve cutter 12 is supported in a vertically movable manner, and the tip of the cutter 12 is shallowly fitted into the cutter insertion hole 9 as shown in Fig. 2 during normal operation of the reactor. In the event of an abnormality in the reactor, the TIP insertion guide tube 8 is moved downward into the gap between the sealing member 6 and the shutoff flange 7 as shown in Fig. 3 while making surface contact therewith, thereby cutting the TIP insertion guide tube 8. It has become.

Further, the indexing device 17 is disposed inside the reactor building 3 outside the containment vessel 2, and selects which of the TIP insertion guide tubes 8 to insert the mobile in-core measuring instrument into. It is.

In the mobile in-core instrumentation device configured as described above, when a detector (not shown) detects that an abnormality has occurred in the reactor, the motor 16 is driven, and this rotational driving force is transferred to the deceleration mechanism 15. is transmitted to the bevel gear 14 via
As a result, the guide screw 13 rotates, and the cutoff valve cutter 12 moves downward from the state shown in FIG. 2 as shown in FIG. 3, cutting all of the TIP insertion guide tube 8. Since the valve cutter 16 is stopped, the shutoff valve cutter 12 is also in the state shown in FIG.

When cutting the TIP insertion guide tube 8, the shutoff valve cutter 12 moves downward while making surface contact with the shutoff flange 7 and the seal member 6, and finally cuts the TIP insertion guide tube 8 as shown in FIG.
The hole in the insertion guide tube 8 is closed. Therefore, even if the reactor is in operation, the indexing device 17 can be inspected or repaired in an area with little radioactive contamination without stopping the reactor, and the time required for the reactor to stop and restart can be inspected or repaired. can be shortened.

In addition, in the above-mentioned embodiment, the cutter supporting structural material 18 includes:
The motor 16 and the deceleration mechanism 15 are supported and fixed, and the deceleration mechanism 1
A bevel gear 14 and a guide screw 13 are rotatably provided between the output shaft of 5 and the flange 5, and a shutoff valve cutter 12 is screwably provided on the guide screw 13. motor 16, deceleration mechanism 15, guide screw 13,
A pulp cutter 12 for blocking may be provided.

In addition, the present invention can be implemented with various modifications without changing the gist.

[Effects of the Invention] According to the present invention described above, the indexing device can be inspected or repaired in an area with little radioactive contamination without stopping the reactor even while the reactor is in operation. It is possible to provide a mobile in-core instrumentation device that can shorten the time required for reactor shutdown and restart.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the mobile in-core instrumentation device of the present invention, and FIGS. 2 and 3 are diagrams for explaining the specific configuration of the TIP flange shown in FIG. 1. . 1...Reactor pressure vessel, 2...Containment vessel wall, 3...
・Reactor building, 4... Through hole, 5... TIP flange, 6... Seal member, 7... Shutoff flange, 8
...Guide tube for TIP insertion, 12...Culp cutter for blocking -13...Guiding screw, 14...Bevel gear, 1
5... Reduction mechanism, 16... Motor.

Claims (1)

[Scope of Claims] A through hole that communicates with the reactor building is formed in a part of the containment vessel that surrounds the entire reactor pressure vessel, and a cylindrical flange that is inserted and fixed into the through hole, and the containment vessel. a sealing member on the inside, fixed within the flange and in contact with the wall of the containment vessel, and having a plurality of guide tube insertion holes; a blocking flange that is inserted and fixed at a predetermined interval and has a plurality of guide tube insertion holes; and a blocking flange that is inserted and fixed in the flange and inserted into the guide tube insertion holes of the sealing member, and the atoms a plurality of TIP insertion guide pipes for inserting mobile in-core instruments (TIPs) along local power range monitors installed in the reactor; and arranged inside the reactor building outside the containment vessel. an indexing device for selecting which one of the TIP insertion guide tubes to insert the mobile in-core measuring instrument into, and an indexing device for selecting whether to insert the mobile in-core measuring instrument into any one of the TIP insertion guide tubes;
It is movable in a direction perpendicular to the P insertion guide tube and can slide into contact between the sealing member and the shutoff flange, so that when an abnormality occurs in the reactor, radioactivity leaks to the outside. A mobile in-core instrumentation device comprising a shutoff valve cutter for cutting each of the TIP insertion guide tubes to prevent the above.