JPH07325186A - Mounting structure of reactor penetration housing - Google Patents

Abstract

PURPOSE:To provide a mount structure of reactor penetration housing in which set range (set freedom) of welding conditions is expanded by avoiding welding of between different metal materials and generation of welding flaw is effectively prevented. CONSTITUTION:The mounting structure of a reactor penetration housing wherein stainless steel control rod drive mechanism housing (CRD housing) 12 is penetrated through a control rod drive mechanism housing penetration hole 13 formed at the bottom end plate 11 of a reactor pressure vessel 10 and welded to couple with an inconel stub tube 15 in the reactor pressure vessel 10, is by forming a housing placing welding part of a CRD housing 12 welded to the stub tube 15 with inconel and thus the welding structure between similar metal materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a through-reactor housing for mounting a control rod drive mechanism housing and an in-core monitor housing on a lower mirror portion of a reactor pressure vessel. The present invention relates to a reactor penetration housing mounting structure for installing a control rod drive mechanism housing and an in-core monitor housing.

[0002]

2. Description of the Related Art In boiling water reactors, a large number of control rod drive mechanism housings (hereinafter referred to as CRDs) are provided in a lower mirror portion of a reactor pressure vessel.
It is called a housing. ) And a plurality of in-core monitor housings (hereinafter referred to as ICM housings) are installed. The CRD housing holds a reactor control rod drive mechanism (hereinafter referred to as CRD) for starting and stopping the reactor and controlling the output. As shown in FIG. 9, the CRD housing 1 is made of stainless steel and is inserted from below into a CRD housing through hole 4 formed in the lower mirror portion 3 of the reactor pressure vessel 2 to penetrate therethrough. It is connected to the inner stub tube 5 made of Inconel by welding.

The ICM housing holds an in-core monitor for detecting a nuclear reaction in the nuclear reactor and is made of stainless steel. As shown in FIG. 10, the ICM housing 6 is inserted from below into the ICM housing through hole 7 formed in the lower mirror portion 3 of the reactor pressure vessel 2 to penetrate therethrough, and the in-core clad portion in the reactor pressure vessel 2 is penetrated. 8 is welded together.

The CRD housing 1 and the ICM housing 6 installed on the lower mirror part 3 of the reactor pressure vessel 2 are made of stainless steel, and the housings 1 and 6 are joined by welding to be installed, and the stub tube 5 and the in-core clad part are installed. Reference numeral 8 is made of Inconel, and is a welding connection between different kinds of metal materials at the site in the reactor pressure vessel 2.

In general, welding of dissimilar metal materials requires a narrower selection range of welding conditions by a welding machine than welding of dissimilar metal materials, and severe welding conditions with less freedom are imposed. Welding conditions are determined by many influencing factors such as current, voltage, torch feed rate, welding material feed rate, and shielding gas type. Particularly, it is well known that it is difficult to set appropriate welding conditions including the welding skill of an operator for Inconel and stainless steel.

Further, the housing installation portion for installing the CRD housing 1 and the ICM housing 6 on the lower mirror portion 3 of the reactor pressure vessel 2 is a portion directly welded to the reactor pressure vessel 2 and the welding work at the site. Therefore, it is desirable to minimize the risk of defects occurring during welding.
In the welding work for the actual installation of the CRD housing 1 and the ICM housing 6, in order to be careful, a welding test is conducted in advance to set the selection range of welding conditions.

[0007]

The welding test is carried out by simulating an actual nuclear reactor, but there are many types of influencing factors that influence the welding conditions, and the influence of minute elemental components contained in the metal material. Therefore, it is necessary to set various welding conditions by using the same charge material and welding material as those used in an actual nuclear reactor, and the amount of welding test material becomes considerable.

Further, it is difficult to prepare a test piece having exactly the same size as that used in an actual nuclear reactor, and due to the difference in construction environment, a new test piece which is not found in a welding test at the time of actual nuclear reactor construction. Welding defects may occur. In that case, it is necessary to repeat the preliminary welding test again and set new welding conditions, but the work involved in these welding tests becomes enormous, and
There is a heavy time, material or financial burden.

The present invention has been made in consideration of the above-mentioned circumstances, and avoids welding of dissimilar metal materials to expand the setting range (setting degree) of welding conditions and effectively prevent the occurrence of welding defects. An object is to provide a mounting structure for a through-reactor housing that is made possible.

Another object of the present invention is to enable welding of similar metal materials to weld a CRD housing or an ICM housing which is installed in a penetrating portion of a reactor pressure vessel, which simplifies a housing welding work in the field and is large. (EN) Provided is a mounting structure for a through-reactor housing which has a high degree of freedom and can be efficiently carried out.

Another object of the present invention is to provide a structure for mounting a through-reactor housing, which greatly simplifies a welding test to be performed in advance and reduces human, time, material and economical burdens. Especially.

[0012]

In order to solve the above-mentioned problems, the structure for mounting a through-reactor housing according to the present invention is formed in the lower mirror portion of a reactor pressure vessel as described in claim 1. A control rod drive mechanism housing through hole is made to penetrate a control rod drive mechanism housing (CRD housing) made of stainless steel and joined to an Inconel stub tube in a reactor pressure vessel by welding. The welding portion for housing installation of the CRD housing is made of Inconel to have a welded structure of metallic materials of the same kind.

In order to solve the above-mentioned problems, the mounting structure of the through-reactor housing according to the present invention has the structure that the welding portion for housing installation of the CRD housing is made of Inconel around the outer periphery of the CRD housing. Inconel buttering structure surrounded by the buttering, or, as described in claim 3, an Inconel replacement structure in which at least the welding portion for housing installation of the CRD housing is made of Inconel material.

Further, in order to solve the above-mentioned problems, the mounting structure of the reactor penetration housing according to the present invention is, as described in claim 4, an in-core monitor formed in the lower mirror portion of the reactor pressure vessel. In a case where a stainless steel in-core monitor housing (ICM housing) is penetrated through the housing through-hole and joined to the in-core clad portion in the reactor pressure vessel by welding, a housing welding portion of the ICM housing to be welded to the in-core clad portion Is made of Inconel to form a welded structure of metallic materials of the same kind.

Further, in order to solve the above-mentioned problems,
As for the mounting structure of the through-reactor housing according to the present invention, as described in claim 5, the housing welding portion of the ICM housing has an Inconel buttering structure in which the outer periphery of the ICM housing is surrounded by Inconel buttering.
In addition, as described in claim 6, an Inconel replacement structure is used in which at least a housing installation welding portion of the ICM housing is made of Inconel material.

[0016]

The mounting structure for the through-reactor housing is defined by claim 1.
And 4 and the welding parts for housing installation of the CRD housing and the ICM housing are formed of Inconel, and the same kind of metal materials are welded to each other. Therefore, the reactor pressure vessel lower mirror of the CRD housing and the ICM housing is formed. It is possible to avoid welding of dissimilar metal materials to each other during installation, to increase the degree of freedom in setting welding conditions, simplify the housing welding work, and perform it efficiently and efficiently. Can be prevented.

The CRD housing and the ICM housing are provided in order to form a welded structure of metallic materials of the same kind.
As described in 5 and 5, the Inconel buttering structure in which the outer periphery of the welding portion for housing installation is surrounded by the Inconel buttering is adopted.

Further, in order to form a welded structure of metallic materials of the same kind, the CRD housing and the ICM housing are constructed as described in claims 3 and 6, and at least the welding portion for housing installation is replaced with Inconel material. Uses a replacement structure. The Inconel substitution structure is
Only the housing installation welding portion of the CRD housing or the ICM housing may be replaced with Inconel material, or the upper portion of the CRD housing or the ICM housing may be replaced.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a structure for mounting a through-reactor housing according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a control rod drive mechanism housing (CRD housing) in which a mounting structure for a through-reactor housing according to the present invention is installed in a lower mirror portion 11 of a reactor pressure vessel 10 of a boiling water reactor in a forested state. The zero applied to 12 is shown.

The CRD housing 12 is the reactor pressure vessel 1
CRD housing through hole 1 formed in the lower mirror portion 11 of 0
3 is inserted so as to penetrate from the lower pedestal room 14 side, and the inserted CRD housing 12 uses a welding machine (not shown) at the top of the stub tube 15 installed in the lower mirror portion 11 of the reactor pressure vessel 10. Are welded together all around.

The lower mirror portion 10 of the reactor pressure vessel 10 is lined with an Inconel material by welding, and an Inconel clad 16 as a mirror-finished Inconel clad portion is integrally formed. The material is further overlay welded to form a stub tube attachment groove weld overlay 17 having a stub tube attachment groove formed on the top. The Inconel stub tube 15 is fixed and installed on the above-mentioned weld overlay 17 by welding. The welding material for welding the stub tube 15 is also formed of Inconel material.

On the other hand, a J groove portion is formed on the top of the stub tube 15, and the CRD housing 12 is formed in this J groove portion.
The housing installation welding parts 18 of 1 are aligned, and the entire circumference is welded by using a welding machine (not shown) to join them. Inconel material is used as a welding material for connecting the CRD housing 12 to the stub tube 15. Reference numeral 19 indicates a welded portion using a welding material of Inconel material.

On the other hand, the CRD housing 12 is constructed as shown in FIG. 2, and a mounting seat (sealing surface) 21 for mounting a control rod guide tube (not shown) is formed on the top thereof. An outer peripheral flange 22 is provided at the bottom of the CRD housing 12.
Is molded, and the control rod drive mechanism is attached via the outer peripheral flange 22.

The housing installation welding portion 18 formed on the upper portion of the CRD housing 12 is formed by an Inconel butter ring 23. An outer peripheral groove 14 is formed in the housing installation welding portion 18, and an Inconel material is welded up (buttered) and fused to the outer peripheral groove 24. Thus, the CRD housing 12 has an Inconel buttering structure in which the outer periphery of the welding portion 18 for housing installation is surrounded by the Inconel buttering 23.

The outer peripheral portion of the housing installation welding portion 18 of the CRD housing 12 is formed of an Inconel buttering structure, and the housing installation welding portion 18 of the CRD housing 12 is provided at the J groove of the Inconel stub tube 15 at a welding machine not shown. The CRD housing 12 is welded to the stub tube 15 by welding the entire circumference thereof and is installed. At this time, the welding material used for the welding machine is the same kind of Inconel material as the butter ring 23 and the stub tube 15 of the housing installation welding portion 18 of the CRD housing 12.

When installing the CRD housing 12 on the stub tube 15 in the reactor pressure vessel 10,
Welding portion 18 for housing installation of CRD housing 12
The same metal material of Inconel is used for the stub tube 15 together with the welding material, and the same metal materials are welded together. Since the housing installation welding portion 18 of the CRD housing 12 and the stub tube 15 are welded to each other by the same kind of metal material and the welding of different kinds of metal materials can be avoided, the selection range of the welding condition can be widened and the welding condition can be increased. The degree of freedom in setting the welding is increased, and the welding work can be simplified.

Further, since the welding conditions are greatly eased and the welding conditions can be set easily and easily, prior to the actual welding operation of the CRD housing 12 to the lower mirror section 11 of the reactor pressure vessel 10. It is possible to greatly simplify or simplify the prior welding test to be performed, and it is possible to significantly reduce the number of welding tests and welding test materials, and reduce human, time, material or economic burden.

FIG. 3 shows a first modification of the CRD housing.

The CRD housing 12A shown in FIG. 3 is a housing installation welding portion 1 formed on the upper part of the housing.
8 is replaced with a sleeve-shaped Inconel material 26, and the Inconel material 26 is made of stainless steel and is connected to the upper housing member 27a, the lower housing member 27b, and the welded portions 28, 28.
It is configured by welding through. Welded part 28
For example, Inconel welding material is used.

This CRD housing 12A also adopts the Inconel replacement structure in which the housing installation welding portion 18 is replaced with the Inconel material 26, so that the welding for installing the CRD housing 12A on the top groove of the Inconel stub tube is the same. Inconel materials, which are metallic materials, are welded together.

FIG. 4 shows a second modification of the CRD housing.

The CRD housing 12B shown in FIG.
The upper part of the housing including the welding part for housing installation is replaced with the Inconel material 30. The CRD housing 12B is configured by joining the Inconel material 30 forming the upper part of the housing to the lower housing 31 made of stainless steel by welding. Reference numeral 32 indicates a welded portion.

Since this CRD housing 12B also has an Inconel replacement structure in which the upper part of the housing including the housing installation welding portion is replaced with Inconel material 30, C
The welding for installing the RD housing 12B in the top groove of the Inconel stub tube is welding of Inconel materials which are the same kind of metal materials.

FIG. 5 shows another embodiment of the mounting structure for the reactor penetration housing according to the present invention.

The housing mounting structure shown in this embodiment has a plurality of in-core monitor housings (ICM housings) mounted on the lower mirror portion 11 of the reactor pressure vessel 10.
An example applied to No. 35 is shown.

The ICM housing 35 is the reactor pressure vessel 1.
ICM housing through hole 3 formed in the lower mirror portion 11 of 0
6, the ICM housing 35 is inserted so as to penetrate from the lower pedestal room 14, and the entire circumference is welded to the top of the in-core clad portion 37 formed in the reactor pressure vessel 10 by using a welding machine (not shown). To be done.

The in-core clad part 37 is lined with inconel material on the lower mirror part 11 of the reactor pressure vessel 10 by welding, and is further overlaid on the mirror-finished inconel clad 16 by welding of inconel material. It is constructed by finishing the built-up part. A J-groove is formed on the top of the in-core clad portion 37, and the IC groove 35 is formed on the J-groove.
The housing installation welding portion 38 formed on the upper part of the housing is aligned and welded. ICM housing 3
An Inconel material is used as a welding material for joining 5 to the in-core clad portion 37. A welded portion using this Inconel material is indicated by reference numeral 39.

On the other hand, the ICM housing 35 is constructed as shown in FIG. 6, and an in-core monitor (not shown) is installed through the lower peripheral flange 40. The housing installation welding portion 38 formed on the upper portion of the ICM housing 35 is formed by the Inconel buttering 41.
An outer peripheral groove 43 is formed in the housing installation welding portion 38, and the Inconel material is welded to the outer peripheral groove 43 by welding and fused by buttering. As a result, the outer periphery of the housing installation welding portion 38 is covered by the Inconel buttering 43.
It is composed of an inconel buttering structure surrounded by.

The outer peripheral portion of the housing installation welding portion 38 of the ICM housing 35 is formed of an Inconel buttering structure, and the entire housing welding welding portion 38 is welded to the top of the in-core clad portion 37 to form an IC.
The M housing 35 is welded to the in-core clad portion 37 and installed. At this time, as a welding material used for connecting the ICM housing 35, an Inconel material which is the same kind of metal material as the buttering 43 of the housing installation welding portion 38 and the in-core clad portion (in-core weld overlay portion) 37 is used.

Therefore, when the ICM housing 35 is installed on the in-core clad portion 37 in the reactor pressure vessel 10, the same metal material of Inconel is welded to the housing installation welding portion 38 of the ICM housing 35 and the in-core clad portion 37. It is used together with the same kind of metal material to form a welded joint. Since the welding portion 38 for installing the housing of the ICM housing 35 and the in-core clad portion 37 are welded to each other by the same kind of metal material, it is possible to avoid the welding of different kinds of metal materials, so that the setting range of welding conditions can be widened. Therefore, the degree of freedom in setting the welding conditions is increased, and the welding work can be simplified and streamlined.

Further, since the welding conditions are greatly eased and the welding conditions can be set easily and easily, the welding test in advance performed prior to the actual welding installation of the ICM housing 35 is greatly simplified. Or it can be simplified, the welding test material can be saved greatly, and human, time,
Material or economic burden can be reduced.

FIG. 7 shows a first modification of the ICM housing.

In the ICM housing 35A shown in FIG. 7, the housing installation welding portion 38 in the upper part of the housing is replaced with a sleeve-shaped Inconel material 45, and the Inconel material 45 is made of stainless steel and is used as an upper housing member 46a and a lower housing member 46b. And welded together via a welded portion 47. Inconel welding material is used for the welding portion 47.

This ICM housing 35A also employs the Inconel replacement structure in which the housing installation welding portion 38 is replaced with the Inconel material 45, so that the welding for installing the ICM housing 35A on the in-core clad portion 37 is made of the same kind of Inconel material. It becomes welding of each other.

FIG. 8 shows a second modification of the ICM housing.

The ICM housing 35B shown in FIG.
The upper part of the housing including the welding part for housing installation is replaced with the Inconel material 48. The Inconel material 48 is joined to the stainless steel lower housing 49 by welding to form the ICM housing 35B.

This ICM housing 35B also has the Inconel replacement structure in which the upper part of the housing including the housing installation welding portion is replaced with the Inconel material 48.
The welding for installing the CM housing 35B in the in-core clad portion 37 is all welding of the same kind of metal material.

[0049]

As described above, in the mounting structure of the through-reactor housing according to the present invention, the CRD housing and the ICM installed on the lower mirror portion of the reactor pressure vessel are installed.
For the welded joint of the housing, it is possible to avoid welding between different metal materials and to weld between different metal materials, so that the selection range of welding conditions can be widened, and the degree of freedom in setting welding conditions increases. The occurrence of defects can be prevented, and the welding work can be simplified and streamlined.

By welding the same kind of metal materials, the welding conditions are greatly relaxed, and the welding conditions can be set easily and easily. Therefore, the actual CRD housing or ICM can be set.
Preliminary welding test performed prior to housing installation can be greatly simplified or simplified, significant reduction of welding test material can be achieved, and human, time, material or economical burden can be reduced. it can.

In the structure for mounting a through-reactor housing according to any one of claims 1 to 3, a dissimilar metal is used to join the CRD housing installed on the lower mirror portion of the reactor pressure vessel to the Inconel stub tube in the reactor by welding. Metal materials of the same kind can be welded and joined together while avoiding welding of materials.

In the structure for mounting a through-reactor housing according to any one of claims 4 to 6, the ICM housing installed on the lower mirror portion of the reactor pressure vessel is welded to the in-core clad portion inside the reactor, and different types are used. It is possible to avoid the welding of metallic materials and to weld and bond metallic materials of the same kind.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a mounting structure for a through-reactor housing according to the present invention.

Fig. 2 CR installed on the lower mirror of the reactor pressure vessel
FIG. 6 is a vertical cross-sectional view showing a D housing.

FIG. 3 is a vertical sectional view showing a first modification of the CRD housing.

FIG. 4 is a vertical sectional view showing a second modification of the CRD housing.

FIG. 5 is a view showing another embodiment of the mounting structure for the reactor penetration housing according to the present invention.

FIG. 6 is an IC installed on the lower mirror part of the reactor pressure vessel.
FIG. 6 is a vertical sectional view showing an M housing.

FIG. 7 is a vertical sectional view showing a first modification of the ICM housing.

FIG. 8 is a vertical cross-sectional view showing a second modification of the ICM housing.

FIG. 9 is a view showing a mounting structure of a CRD housing as a conventional reactor penetration housing.

FIG. 10 is a view showing a mounting structure of an ICM housing as a conventional reactor penetration housing.

[Explanation of symbols]

10 Reactor Pressure Vessel 11 Lower Mirror 12, 12A, 12B Control Rod Drive Mechanism Housing (C
RD housing) 13 CRD housing through hole 15 Stub tube 16 Inconel clad (Inconel overlay part) 18,38 Welding part for housing installation 23 Inconel buttering 26,30 Inconel material 35,35A, 35B Incore monitor housing (I
CM housing) 37 Incore clad 43 Inconel buttering 45,48 Inconel material

Claims (6)

[Claims] 1. A control rod drive mechanism housing (CRD housing) made of stainless steel is penetrated through a control rod drive mechanism housing through hole formed in a lower mirror portion of the reactor pressure vessel, and made of Inconel in the reactor pressure vessel. In what is welded to the stub tube by welding, the welding portion for housing installation of the CRD housing to be welded to the stub tube is formed of Inconel, and a weld structure of the same kind of metal material is formed. Mounting structure. 2. The mounting structure for a nuclear reactor penetrating housing according to claim 1, wherein the welding portion for housing installation of the CRD housing has an Inconel buttering structure in which an outer periphery of the CRD housing is surrounded by Inconel buttering. 3. The nuclear reactor penetrating housing mounting structure according to claim 1, wherein an inconel replacement structure is formed by using at least a housing installation welding portion of the CRD housing as an inconel material. 4. A stainless steel in-core monitor housing (ICM housing) is made to penetrate through an in-core monitor housing through hole formed in the lower mirror portion of the reactor pressure vessel and welded to the in-core clad portion in the reactor pressure vessel. In the combined structure, the housing installation welding portion of the ICM housing to be welded to the in-core clad portion is formed of Inconel to have a welding structure of the same kind of metal materials, and a mounting structure for a through-reactor housing. 5. The reactor penetration housing mounting structure according to claim 4, wherein the welding portion for housing installation of the ICM housing has an Inconel buttering structure in which the outer periphery of the ICM housing is surrounded by Inconel buttering. 6. The mounting structure for a through-reactor housing according to claim 4, wherein an Inconel replacement structure is formed by using an Inconel material in at least a housing installation welding portion of the ICM housing.