JP3020879B2 - Adjusting method of core of reactor internal structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of aligning a core by mounting an upper lattice plate and a core support plate , which are internal structures of a reactor, on a shroud, which is one of the support structures in the reactor. />

[0002]

2. Description of the Related Art A shroud, which is an internal structure of a nuclear reactor, includes:
Three flanges of an upper flange, an intermediate flange, and a lower flange and three trunks of an upper trunk, an intermediate trunk, and a lower trunk are formed by welding.

[0003] Further, an upper lattice plate and a core support plate, which are internal structures of the reactor, are mechanically attached to an intermediate flange and a lower flange of a shroud, respectively. In such a case, the core adjustment of the upper lattice plate and the core support plate has been performed with the adjustment pins attached to the respective structures in advance. Conventionally, as described in Japanese Patent Application Laid-Open No. 62-121391, when the upper grid plate is installed on the shroud intermediate flange, an adjustment pin is attached from the lower side of the upper grid plate in advance, and the core is inserted from above the upper grid plate. He suggested a way to make adjustments. However, JP-A-62-121391
The proposal in No. 1 is a remotely controllable adjusting device for the upper lattice plate, and does not describe a method for adjusting the core of the core support plate. Further, the core adjustment device cannot be attached to the furnace internal structure by remote control, and cannot be removed after the core adjustment is performed.

[0004]

In the case where replacement of a reactor internal structure such as a shroud is supposed to be performed during operation of the nuclear reactor, the above-described core adjusting device is installed below the reactor internal structure. In this case, workers would have to approach or access the upper lattice plate and core support plate, and it would be very difficult to work in an activated furnace. . In addition, operating the reactor with the core adjustment device attached to the reactor internals increases the amount of activated reactor internals and increases the possibility of loose parts during operation. Conceivable.

SUMMARY OF THE INVENTION It is an object of the present invention to remotely mount and remove a core adjustment device when installing an upper lattice plate and a core support plate on a shroud and performing core adjustment. It is intended to provide a method for mounting a reactor internal structure which can perform the following.

[0006]

To achieve the above object of the Invention The present invention comprises a first round bar, the central axis Re et provided on the lower side of the first round bar deviates diameter said and a smaller second rod than one round bar, the radius and the second of said first rod
Of the inner structure of the reactor using a core adjusting device whose difference from the radius of the round bar is larger than the deviation amount of the center axis of these two round bars .
A wick adjustment method, the core support plate provided with a guide for inserting the core adjusting device at a plurality of locations of the outer peripheral portion, the groove
Placed on top of the formed shroud lower flange, inserting the core adjusting device from above into the core support plate of the guide, the core support plate is displaced in a horizontal direction by rotating the core adjustment equipment The center adjustment is performed, and then the center adjustment device is removed upward. Also, the first round bar and the middle
A second round bar having a center axis shifted and provided below the first round bar and having a diameter smaller than the first round bar, wherein a radius of the first round bar and a second round bar are provided. Use a core adjustment device whose difference from the radius of the round bar is larger than the deviation of the center axis of these two round bars.
And a core adjustment method of the reactor furnace structure, an upper lattice plate having a guide for inserting the core adjusting device at a plurality of locations of the outer peripheral portion, on the groove shroud intermediate flange which is formed the loaded, inserting the core adjusting device from above into the upper grid plate of the guide, the upper grid plate is displaced in a horizontal direction by rotating the core adjustment equipment performs core adjustment, then the core Remove the adjustment device upwards.

According to the present invention, when assuming replacement of a reactor internal structure, etc. , the core adjusting device can be remotely attached / detached to the upper lattice plate and the core support plate, and Can be used to adjust the core. Further, since the worker does not need to access the lower part of the upper lattice plate and the core support plate, the work is easy.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a lead adjusting device 1 according to the present invention.
It is shown.

The core adjusting device 1 includes a bolt 1a for turning the device, and a fall prevention flange 1 for preventing the core adjusting device 1 from dropping when the core adjusting device 1 is mounted on the internal structure of the reactor.
b, the diameter of the shaft 1c is smaller than that of the shaft 1c, and the center of the shaft 1c is shifted from that of the shaft 1c. The axis 1d satisfies the condition that the deviation amount is larger than the deviation amount δ.

With such a structure, a core adjusting device can be provided which can be attached to and removed from above the reactor internal structure.

Further, bolt 1a is not convex structure as shown in FIG. 1, it may be a concave. In addition, the fall prevention flange 1b may have not only a circular shape as shown in FIG. 1 but also a tapered shape at a contact portion with a reactor internal structure.

In FIG. 2, several shroud support legs 3 are provided upright on the lower mirror portion 2a of the reactor pressure vessel 2 over the entire circumference, and a body 2b of the reactor pressure vessel has
An annular shroud support plate 4 is fixed by welding. Above the shroud support leg 3, a cylindrical shroud support ring 5 is fixed to the shroud support leg 3 and the shroud support plate 4 by welding. A shroud 6 is provided on the shroud support ring 5. A core support plate 7 is provided on a lower flange 6 a of the shroud 6, and an upper lattice plate 8 is provided on an intermediate flange 6 b of the shroud 6.

FIGS. 3 and 4 show a lead adjusting device 1 according to the present invention.
This is an example of the application.

FIG. 3 shows an embodiment in which a core adjusting device is applied to a core support plate which is a reactor internal structure. At a plurality of locations on the outer peripheral portion of the core support plate 7, guides 7c for inserting the core adjusting device are fixed to the top plate 7a and the rim barrel 7b for mounting the core adjusting device 1. A groove 6c is provided in advance in the shroud lower flange 6a. After the core support plate 7 is seated on the shroud lower flange 6a, the core adjusting device 1 is placed on the core support plate 7 from above the core support plate.
Into the guide 7c. Then, by rotating the bolt 1a attached to the upper part of the core adjustment device 1,
Horizontal force is transmitted from the core adjustment device 1 to the groove 6c of the shroud, and the core support plate 7 can be displaced in the horizontal direction to perform core adjustment. After the core adjustment, the core support plate 7 is again adjusted.
The lead adjustment device 1 can be detached upward from above.

FIG. 4 shows an embodiment in which a core adjusting device is applied to an upper lattice plate which is an internal structure of a nuclear reactor. Guides 8a for inserting the core adjusting device are fixed to a plurality of locations on the outer peripheral portion of the upper lattice plate 8, similarly to the core support plate. The shroud intermediate flange 6b is provided with a groove 6d in advance. After the upper lattice plate 8 is seated on the intermediate flange 6b, the core adjusting device 1 is inserted into the guide 8a of the upper lattice plate 8 from above the upper lattice plate. Then, by rotating the bolt 1a attached to the upper part of the lead adjusting device 1, a horizontal force is transmitted from the lead adjusting device 1 to the shroud 6, and the upper lattice plate 8 is displaced in the horizontal direction.
The makes it possible to wick adjustment. Further, after completion of the core adjustment, the core adjustment device 1 can be removed again above the upper lattice plate 8.

[0016]

According to the present invention, when performing the core adjustment of the reactor internal structure, the mounting and dismounting of the core adjustment device can be performed remotely, and the core adjustment can be performed by remote control. Make it possible.

[Brief description of the drawings]

FIG. 1 is a structural view of a core adjusting device.

FIG. 2 is a structural diagram inside a nuclear reactor.

FIG. 3 shows an embodiment in which a core adjusting device is applied to a core support plate.

FIG. 4 is an embodiment in which a core adjusting device is applied to an upper lattice plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Core adjustment device, 2 ... Reactor pressure vessel, 3 ... Shroud support leg, 4 ... Shroud support plate, 5 ...
Shroud support ring, 6: shroud, 7: core support plate, 8: upper lattice plate.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuo Tada 3-1-1 Sachimachi, Hitachi-shi, Ibaraki Hitachi, Ltd. Inside the Hitachi Plant (72) Inventor Kenichi Nibe 3-2-2 Sachimachi, Hitachi-shi, Ibaraki No. 2 Hitachi Nuclear Engineering Co., Ltd. (56) References JP-A-10-48378 (JP, A) JP-A-10-2985 (JP, A) JP-A-7-305709 (JP, A) 2-113110 (JP, A) JP-A-60-147792 (JP, A) JP-A-59-98398 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21C 13/00 G21C 19/02 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. A includes a first round bar and a second round bar formed al Re diameter on the lower side smaller than the first rod of the first round bar with off-center axis, The core of a nuclear reactor internal structure using a core adjustment device in which the difference between the radius of the first round bar and the radius of the second round bar is larger than the amount of deviation of the central axes of these two round bars.
A method for adjusting, out of the core support plate provided with a guide for inserting the core adjusting device at a plurality of locations in the circumferential portion, placed on the shroud lower flange groove is formed, from said upper core adjuster was inserted into the reactor core support plate of the guide in the displaces the core support plate in the horizontal direction by rotating the core adjustment equipment performs core adjustment, characterized in that subsequently removing the core adjuster upward Adjustment method of core of reactor internal structure. 2. A comprises a first round bar, diameter provided on the lower side of the central axis deviated first round bar and a second round bar less than the first round bar, the The core of a nuclear reactor internal structure using a core adjusting device in which the difference between the radius of the first round bar and the radius of the second round bar is larger than the amount of deviation of the central axes of these two round bars.
A method for adjusting, out of the top guide having a guide for inserting the core adjusting device at a plurality of locations in the circumferential portion, placed on the shroud intermediate flange which the grooves are formed, from said upper core adjuster was inserted into the guide of the upper grid plate, said displacing the upper grid plate in the horizontal direction by rotating the core adjustment equipment performs core adjustment, characterized in that subsequently removing the core adjuster upward Adjustment method of core of reactor internal structure.