JPS62854A - Inspecting device for pressure container - Google Patents

Abstract

PURPOSE:To perform the in-service inspection (ISI) of the core part of a reactor pressure vessel easily and accurately by providing a mast which is supported on a carriage moving along a ring girder and expansible in the upper and lower directions of the pressure vessel. CONSTITUTION:The carriage 14 is moved along the ring girder 13 installed at the main flange part 12 of the reactor pressure vessel 1. An upper mast 16 which has an expansible lower mast 18 is fitted to the carriage 14 across a reinforcing body 17. An arm 19 which moves in a peripheral direction along the wall surface of the pressure vessel 1 is provided to the lower end part of the mast 18 and a sensor which inspects the pressure vessel 1 is provided at the top of the arm 19. The carriage 14 is moved along the ring girder 13 to a specific position, the mast 18 is lowered from the position while avoiding an obstacle in a narrow space, and then the arm 19 is moved in the peripheral direction of the vessel to perform ultrasonic flaw detection, television observa tion, etc., from the internal surface side of the pressure vessel 1 by the sensor provided at the top of the arm 19.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an inspection device for a pressure vessel, and in particular, an inspection device suitable for inspecting a reactor pressure vessel during its service life from the inner surface of the reactor pressure vessel. It is related to.

[Background of the invention]

Power reactors are inspected once a year during their service life (In-3).
service (nspectton, hereinafter referred to as “
131”) is required, and the reactor pressure vessel (Reactor Pressure Vessel
% or less (hereinafter abbreviated as 'RPV°), etc., inspection of pressure-resistant welds, etc. is required.

The purpose of implementing ISI is to ensure that there are no defects in the pressure-resistant parts such as the RPV throughout the service life (or life span) of the reactor.
The purpose is to periodically check that it is sound and there is no risk of damage. Regarding the RPV, the steel material near the reactor core is expected to become embrittled by neutron irradiation, so this is a particularly important part from the perspective of checking the integrity using ISI.

For this reason, boiling water nuclear power plants (Boiling Water Reactor), which have been constructed in recent years, are
, hereinafter abbreviated as "BWR plant 1"),
As shown in FIGS. 19 and 20, the inner diameter of the biological barrier body 2 is made slightly larger than the outer diameter of the RPVI, and the R
An appropriate gap 4 is provided between the PVI and the insulation material 3, and inspection equipment is installed and moved in this gap 4 to check the ISI of the RPVI.
The plant has been designed and manufactured with consideration given to implementing this from the outside of the RPV.

However, the design and
In the old plants that were manufactured, consideration was not given to implementing ISI from the outside of the RPV as has been done in recent years, and therefore the gap 4 was narrow and the structure was such that the insulation material 3 could be removed. Therefore, it is difficult to perform step 131 from the outside of the RPV.

Therefore, for such old plants, RP
It is conceivable to perform ISI from the V inner surface side. In fact, due to structural constraints, I
Pressurized water nuclear power plants (Pr
Essurized Water Reactor,
In RPVs (hereinafter referred to as "PWR plants"), ISI is usually performed underwater from the inside of the RPV, and devices for such ISI have been devised and put into practical use.

However, in the case of BWR, it is not easy to perform PWR 131 from the inside of the RPV. That is, in the case of PWH, 1. When performing S I, the reactor internals inside the RPV can be removed outside the RPV.Therefore, there are no obstacles inside the reactor for ISI implementation, so it is impossible to approach the RPV inner wall from inside the reactor. On the other hand, in the case of a BWR, as shown in Figs. 21 to 23, there are permanent facilities in the reactor such as a shroud 5, an upper shroud 6, a water supply sparger 7, a core spray inner pipe 8, and a shroud head. Due to the presence of bolt lugs 9, etc., in order to approach the inner wall of the RPV core region near the core 10, it is necessary to approach while avoiding these reactor internals.In particular, the gap d is approximately 1
The cI is extremely narrow at around 11, and the gap e between RPV 1 and shroud 5 is also narrow, making it a large PWRSR.
With PV equipment, it is not possible to approach the inner walls of the BWR and RPV core regions and perform 131 due to dimensional constraints. The emergence of a device that can perform ISL is eagerly awaited.

[Purpose of the invention]

The purpose of the present invention is to provide a pressure vessel inspection device that can easily and accurately perform RPV of an old BWR plant, especially 131 of the RPV core, where 131 has traditionally been difficult to perform as described above. It is about providing.

[Summary of the invention]

The present invention provides a mast that is supported by a carriage that moves along a ring gutter installed on the main flange of a pressure vessel and is extendable and retractable in the vertical direction of the pressure vessel. The pressure vessel can be inspected from the inside using a sensor installed at the tip of the arm.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention, and this pressure vessel inspection device includes a ring gutter 13 installed on a main flange 12 of a reactor pressure vessel
3, a mast guide 15 attached to this carriage 14, an upper mass (16) guided into the reactor core by this mast guide 15, and an upper mast reinforcement body 17 that reinforces this upper mast 16. and,
The main components include a lower mast 18 connected to an upper mast 16, an arm 19 movably supported by the lower mast 18, and a head 20 attached to one end of the arm 19.

The ring gutter 13 is attached to the main flange 1 of the reactor pressure vessel 1.
2, installed along the top of the carriage 14 and the upper mass)
A carriage 14 is installed movably along the ring gutter 13 and has sufficient strength to support the entire weight of the ring gutter 15 and the like.

As shown in FIGS. 1 and 2, the carriage 14 includes a top plate 14A and an arc-shaped carriage side plate 14B, and a carriage drive source 21 is provided on the top plate 14A. Wheels (not shown) installed on the bottom side of the carriage 1 are driven.
4 can run along the ring gutter 13.

A pair of upper mast drive sources 22 are installed adjacent to the carriage drive source 21, and each upper mast drive source 22 has a pinion A27, and each pinion A is meshed with a rack A31 of the upper mast 16. This rack and pinion mechanism allows the upper mast 16 and the upper mast reinforcement body to move up and down in the vertical direction of RPvl. Further, a pair of hinge flanges 28 are attached to the upper surface plate 14A of the carriage 14.

As shown in FIG. 3, rollers A29 are provided at each of the four corners of the mast guide 15, and a piston bracket 30 is provided at the lower end of the side surface of the mast guide 15, respectively.
As shown in B), a mast tilt adjustment mechanism 24 is installed to move the mast in the direction of the arrow. And the piston bracket 30 is Kya.

It is pivotally connected to a pin bracket 26 installed on the ridge side plate 14B. Further, projections 15A are formed on the upper end surfaces of the side surfaces of the mast guide 15, and the projections 15A
is pivotally supported by a hinge bracket 28 provided on the upper surface plate 14A of the carriage.

As shown in FIG. 4, the upper mast 16 is provided with an upper mast reinforcing body 17 for increasing the deformation rigidity of the upper mast itself. The roller A29 shown in the figure is engaged. The upper mast 16 is formed into a pipe shape, and the lower mast 1B is movably inserted into the upper mast 16.
is adapted to move in the vertical direction of the RPV 1 by a lower mast drive source 23.

As shown in FIGS. 5 and 6, an arm drive source 25 is installed at the lower end of the lower mast 18, and this arm drive source 25
A pinion B34 is provided which is driven by
A rack B35 is formed along the longitudinal direction of each of the two arcuate arms 19, and the pinion B34 meshes with the rack B35 formed on the arm 19. Grooves are formed along the longitudinal direction on both end surfaces of the arm 19 in the vertical direction, and the rollers 33 are engaged with these grooves. Further, a sensor assembly 36 containing a plurality of ultrasonic probes, a television camera, etc. is installed in the head 20 fixed to both ends of the arm 19 in the longitudinal direction.

Next, the operation of the pressure vessel inspection apparatus configured as described above will be explained.

7 to 12 show an example of how to approach the RPV core region and the operation of each part of the inspection apparatus according to the present invention.

In FIG. 7, a carriage drive source 21 installed on the carriage 14 is driven, and the carriage 14 travels along the ring gutter 13 and stops at a predetermined position. . At this time, the lower mast 18 is housed within the upper mast 16, and the upper mast 16 and upper mast reinforcing plate 17 are located above the mast guide 15.

After the carriage 14 stops at a predetermined position on the ring gutter 13, the upper mast drive source 22 is driven while maintaining the verticality of the upper mast 16 as shown in FIG. 8, and the pinion A27 of this mast drive source 22 is driven. As the upper mast 16 rotates, the upper mast 16 having the rack A31 engaged with the pinion A27, together with the upper mast reinforcement 17, vertically descends along the inner surface of the core of the RPVI. The lowering of the upper mast 16 stops at a position where the arm 19 installed at the lower end of the lower mast 18 housed in the upper mast 16 approaches above the water supply sparger 7.

Next, the piston bracket 30 is moved to the RPV by driving the mast tilt adjustment mechanism section 24 installed in the mast guide 15.
The mast guide 15 is inclined toward the center of the RPVI with the protrusion 15A extending toward the I side and pivotally supported by the hinge bracket 28 as a base point.

As the mast guide 15 inclines, the upper mast 16 inclines as shown in FIG. It is stopped at a distant position by the sparger 7.

In this way, the mast drive source 22 is driven while maintaining the inclination angle of the mast, and the rack A31 and the binion A2 are driven again.
7, the arm 19 installed at the lower end of the lower mast 18 housed in the upper mast 16 stops descending when it is located above the upper shroud 6, as shown in FIG.

Next, as shown in FIG. 11, the upper mast 16 is maintained in the vertical state again by driving the mast inclination adjustment mechanism section 24 installed in the mast guide 15.

In this state, as shown in FIG.
is driven, and the lower mast 1 is housed in the upper mast 16.
8 is vertically lowered, and the arm 19 installed at the lower end of the lower mast 18 stops at a predetermined gap to be inspected between the outer peripheral surface of the sheroud 5 and the inner peripheral surface of the RPV 1.

By the operations shown in FIGS. 7 to 12, the inspection device can be guided to a predetermined position while avoiding obstacles such as a water supply sparger.

13 to 15 show an example of the operation of the arm 19.

FIG. 13 shows that the arm 19 is connected to the outer peripheral surface of the shroud 5 and the RPV.
This figure shows the state when the robot is stopped at a predetermined gap between the inner circumferential surface of I and the inner circumferential surface of I. FIG. 16 shows a cross-sectional view of the situation when the arm is stopped, and the arm drive source 25 and head 20 are each located in the space between the Radbolt lug 9 and the shroud.

Therefore, as mentioned above. In FIG. 7, the carriage 14
is run along the ring gutter 14, and the carriage 14
When adjusting the positions of the arm drive source 25 and the head 20, the positions are adjusted such that the arm drive source 25 and the head 20 can each pass through the space between the Radbolt lugs 9 to the shroud.

After the arm 19 stops at a predetermined position, the arm drive source 2
5 rotates the binion B34, and as shown in FIG. 14, the two arms 19 having the rack B35 that meshes with the binion B34 are driven in opposite directions.
Head 20 fixed to one end side of arc-shaped arm 19
can move along the inner surface of the RPVl and perform ultrasonic flaw detection in the RPV core region.

Next, as shown in FIG. 15, the arm drive source 25 drives the pinion B 34 to rotate in the opposite direction to that shown in FIG. The installed sensor assembly 36゛ is R
Move along the inner surface of the PVI. One of the two sensor assemblies 36 is installed as a backup in case the other sensor assembly 36 fails, but the two arms 19
By installing the sensor assembly 36 on one end side of each of the lower masts 18, it is possible to balance the left and right sides of the lower mast 18, and even when the lower mast 18 is made thinner, deformation of the lower mast 18 can be prevented. Furthermore, since the arm 19 is arc-shaped, the RPVI can be inspected even in the narrow space between the RPVl and the shroud 5.

17 and 18 show an example of the operation of the helad 20. The sensor assembly 36 in the head 20 is installed so as to be able to protrude from the head 20, and the arm 19 is stopped at a predetermined position to be inspected. At this time, the head 20 is housed in the head 20 as shown in FIG. 17, and the arm 19 is in a predetermined position for inspection.
9 is driven in the horizontal direction, and the sensor assembly 36 is moved horizontally to the head 20 as shown in FIG.
The distance l is adjusted. With this mechanism, the distance (water distance) between the sensor assembly 36 and the inner surface of the RPV 1 can be adjusted to the optimum inspection distance.

In addition, the carriage 14, the upper mast 16, and the lower mast 1
8, the mechanism for causing the arm 19, the mast tilt adjustment mechanism 24, and the sensor assembly 36 to protrude from the head 20 can be driven by remote automatic operation, remote manual operation, or a combination thereof.

(Effects of the Invention) As described above, according to the present invention, a ring gutter installed on the main flange of a pressure vessel, a carriage that moves along the ring gutter, and a carriage supported by the carriage and mounted on the pressure vessel. An extendable mast that moves vertically, an arm installed at the lower end of the mast that moves circumferentially along the wall of the pressure vessel, and an arm installed at the tip of the arm that inspects the pressure vessel from the inside of the pressure vessel. The carriage is equipped with a sensor that moves the carriage along the ring gutter to a predetermined position, then lowers it from that position while avoiding obstacles in a narrow space, and then moves the arm in the circumferential direction of the container at the predetermined position. By moving along the arm, ultrasonic flaw detection, television observation, etc. can be performed from the inner surface of the pressure vessel such as the RPV core region using the sensor provided at the tip of the arm.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the pressure vessel inspection apparatus of the present invention, FIG. 2(A) is a front view of the carriage in the pressure vessel inspection apparatus of FIG. Figure (A) is a plan view, Figure 3 (A) is a front view of the mast guide in the pressure vessel inspection equipment in Figure 1, and Figure 3 (B) is Figure 3 (A).
), FIG. 3(C) is a plan view of FIG. 3(A), FIG. 4(A) is a front view of the mast in the pressure vessel inspection apparatus of FIG. 1, and FIG. 4(B) is a side view of Figure 4 (A) side view, 4th
Figure (C) is a plan view of Figure 4 (A), Figure 5 (A) is the top view of Figure 1
5(B) is a side view showing a partial cross section of FIG. 5(A), and FIG. 5(C) is a direction D in FIG. 5(A). An end view; FIG. 6 is a sectional view showing the arrangement of the arm and head shown in FIG. 5(A);
Figure 7, Figure 8, Figure 9, Figure 10, Figure 11 and Figure 1
Figure 2 is a cross-sectional view showing how the arm and head approach the core area, Figures 13, 14 and 15 are explanatory diagrams showing the operation of the arm, and Figure 16 is a cross-sectional view showing how the arm and head approach the core area. 17 and 18 are explanatory diagrams showing the operation of the sensor assembly, FIG. 19 is a vertical sectional view showing the reactor building and RPV, and FIG. 20 is the same as in FIG. 19. Enlarged sectional view of part A, Figure 21 is B
22 is a longitudinal sectional view showing the WR reactor internals, FIG. 22 is a sectional view taken along line BB in FIG. 21, and FIG. 23 is an enlarged view of section C in FIG. 22. 1... RPV pressure vessel, 2... Living body shield, 3... Heat insulation material, 4... Gap, 5... Shroud, 6...Upper shroud, 7...Water supply sparger, 8...
・Core spray inner tube, 9... Radbolt lug to shroud, 10... Core, 11...
Sparger elbow, 12... Reactor pressure vessel main flange, 13... Ring gutter, 14...
... Carriage, 15 ... Mast guide, 1
6... Upper mast, 17... Upper mast reinforcement, 18... Lower mast, 19...
...Arm, 20...Head, 21...
- Carriage drive source, 22... Upper mast drive source, 23... Lower mast drive source, 24...
...Mast tilt adjustment mechanism section, 25...Arm drive source, 26...Pin bracket, 27...
...Pinion A, 28...Hinge bracket,
29...Roller A130...Piston bracket, 31...Rank A, 32...
...Rail, 33...Roller B. 34... Binion B135... Rack B136... Sensor assembly.

Claims (11)

[Claims] (1) A device for inspecting a pressure vessel from the inside side, which includes a ring gutter installed on the main flange of the pressure vessel, a carriage that moves along the ring gutter, and a carriage that is supported by the carriage in the vertical direction of the pressure vessel. A mast that is extendable and retractable to move, an arm that is installed at the lower end of the mast and that can move in the circumferential direction of the vessel along the wall surface of the pressure vessel, and an arm that is installed at the tip of this arm that inspects the pressure vessel from the inside of the pressure vessel. A pressure vessel inspection device comprising: a sensor; (2) The pressure according to claim 1, wherein the mast comprises an upper mast and a lower mast movably provided within the upper mast, and the arm is provided at the lower end of the lower mast. Container inspection equipment. (3) The pressure vessel inspection device according to claim 1, wherein the carriage and the mast have a symmetrical structure with respect to a longitudinal plane including the central axis of the pressure vessel and the central axis of the mast. (4) The pressure vessel inspection device according to claim 1, wherein the arm is arcuate. (5) The arm consists of an arm having a pressure vessel inspection sensor and an arm having a pressure vessel inspection preliminary sensor, and the arm and the sensor are arranged in a longitudinal plane including the pressure vessel center axis and the mast center axis. The pressure vessel inspection device according to claim 1, which has a mutually symmetrical structure and is provided movably in mutually opposite directions. (6) Claim 1, wherein the sensor provided on the arm is provided with a mechanism capable of adjusting the distance between the sensor and the wall surface of the pressure vessel by adjusting the distance by which the sensor projects in the circumferential direction of the pressure vessel. The pressure vessel inspection device described. (7) The pressure vessel inspection device according to claim 2, further comprising an upper mast reinforcing body for reinforcing the upper mast. (8) The upper mast is held by a mast guide having rollers and engaging with a carriage.
Pressure vessel inspection equipment as described in section. (9) The mast guide has a structure that engages with the carriage through a hinge, and includes a mast inclination adjustment mechanism that adjusts the distance between the carriage and the mast guide to adjust the inclination angle of the upper mast center axis with respect to the pressure wall surface. A pressure vessel inspection device according to claim 8. (10) The pressure vessel inspection device according to claim 1 or 6, wherein the sensor is an ultrasonic flaw detection probe or a television camera. (11) The carriage, upper mast, lower mast, arm, mast tilt adjustment mechanism, and mechanism capable of adjusting the distance between the sensor and the container wall surface can be driven by remote automatic operation, remote manual operation, or a combination of these operations. A pressure vessel inspection device according to any one of claims 1 to 9.