JP2005017002A - Nondestructive inspection method of different material brazing section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish a non-destructive inspection method of a diverter that is radiated during service by solving the problems that the attenuation of ultrasonic waves is large at an armor tile section in an ultrasonic method, and the attenuation of X rays is also large so that a transmission image at the narrow brazing section between the armor tile and a cooling substrate cannot be obtained, and measurement sensitivity is not sufficient in thermography in the non-destruction inspection of a structure, where the junction structure of a different material, such as a fusion reactor diverter target plate, and a cooling function structure have become complicated, and a brazed section. <P>SOLUTION: In the method, the non-destructive inspection of the different material brazed section of a structure comprising a three-layer laminated structure of armor tile/brazed section/cooling substrate (having a cooling channel) in a fusion reactor is made by a neutron radiography method utilizing low-energy neutron rays having improved transmission force and a small amount of attenuation by a body to be inspected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００１１】
【表２】

【００１２】
【表３】

【００１３】
表１には、図２の装置を使用し、その試験室（ＴＮＲＦ−１及びＴＮＲＦ−２）のサンプルホルダー及びサンプルテーブルにＩＴＥＲ（核融合炉）用ダイバータターゲットプレート実機（被検査体）を置き、中性子束を照射した場合の条件が示されている。表２には、図２の装置において、その被検査体を透過した中性子線又はＸ線を、特定の写真フィルム及び露出時間で、中性子テレビカメラを用いて撮影した場合の結果が示されている。表３には、被検査体に、中性子ラジオグラフィ（ＮＲＧ）、Ｘ線法（ＸＲＧ）、サーモグラフィ法及び超音波法を使用して得られた最小欠陥サイズが表示されている。これによると、中性子ラジオグラフィによる最小欠陥サイズが一番小さいことが示されている。
【００１４】
【発明の効果】
本発明により、各種ろう接部及び複数積層複雑構造体の非破壊検査が可能となるので、ＩＴＥＲ等の核融合実験炉や核融合発電炉における複雑な構造物体の非破壊検査、供用中検査を実施でき、運転の効率化が図られる、という本発明に特有の顕著な効果を生ずる。
【図面の簡単な説明】
【図１】ＩＴＥＲダイバータターゲットプレート概念図と実機を示す図である。
【図２】中性子ラジオグラフィ利用原子炉施設を示す図である。
【図３】ダイバータターゲットプレート断面解析モデル図及び欠陥想定箇所を示す図である。[0001]
[Technical field to which the invention belongs]
The present invention relates to a non-destructive inspection method for dissimilar material brazing parts used in the nuclear industry field and the general industry field (such as a gas turbine coated blade having a cooling structure inside a blade).
[0002]
[Prior art]
Non-destructive inspection technology for brazed parts has not yet been established at present, such as a fusion reactor divertor target plate and other structures with a complex joining structure and cooling function structure.
[0003]
[Problems to be solved by the invention]
As shown in FIG. 1, in the non-destructive inspection of a brazed portion in a non-destructive inspection of a structure having a complicated joining structure and cooling function structure of different materials such as a fusion reactor divertor target plate, the armor tile portion Since the attenuation of the ultrasonic wave is large and the attenuation of the X-ray is also large, a transmission image of the narrow brazed portion between the armor tile and the cooling substrate cannot be obtained clearly. In addition, measurement sensitivity is insufficient in thermography. In addition, no non-destructive inspection method has been established for in-service activated diverters that perform periodic inspections, etc., by temporarily stopping the apparatus during experiments and operations.
[0004]
[Means for Solving the Problems]
The present invention obtains the resolution required for narrow brazing joint inspection without the above-mentioned attenuation due to each material of different kinds of laminated materials by a neutron radiography method using a low energy neutron beam having excellent transmission power and low attenuation. This is a non-destructive inspection method. Furthermore, although the divertor is activated in the inspection during the service period, the non-destructive inspection of the activated diverter structure can be performed by using a neutron radiography measurement facility.
[0005]
In other words, the activated object to be inspected, such as the activated divertor, is placed on the sample table by remote control of a robot or the like within the radiography control area, and the sample table is rotated and moved between the neutron beam and the sensor by vertical movement. It is possible to observe the bonding interface and the matrix from all angles. In addition, since the radiography apparatus and its facility are in the radiation control area, the activated diverter can be easily handled, and can be inspected without disassembling and removing for radiography measurement.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As shown in the upper part of FIG. 1, the structure of a fusion reactor diverter is composed of a buffer, a dome, a wing and a target plate, and the exhaust gas generated during the fusion reaction in the vacuum chamber of the fusion reactor Then, it is cooled and discharged through the target bumper. As shown in the lower part of FIG. 1, the target plate is composed of a three-layered structure of an armor tile made of a C / C composite material, an inner layer of a brazed part made of highly conductive oxygen-free copper, and a heat sink as a cooling substrate. Has been. In the present invention, incomplete defects in the brazed portion of this three-layer laminated structure can be inspected nondestructively by a neutron radiography method using a low energy neutron beam having excellent transmission power and low attenuation. . As shown in FIG. 1, the target plate of the diverter is a structure composed of an elongated cooling water pipe and an armature such as graphite brazed to the surface thereof.
[0007]
When non-destructively inspecting an object to be inspected using neutron radiation by the neutron radiography method, as shown in FIG. 2, the neutron beam is taken out from the reactor core through a heavy water tank and a beam shutter. A test object placed on a sample holder or a sample table is irradiated with a neutron beam, and the transmitted beam is captured by a neutron television camera to inspect the brazed portion of the test object.
[0008]
FIG. 3 is a mesh model of the target plate when cracks are present on the inner surface of the joint between the armor and the cooling channel, and shows a case where the check surface has a defect.
[0009]
【Example】
The nondestructive inspection test of the actual divertor target plate for ITER (Fusion Reactor) was performed using the neutron radiography (NRG), X-ray method (XRG), ultrasonic method, and thermography method in the conditions shown in Tables 1 and 2. The detection sensitivity comparison of the incomplete brazing in the brazing portion between the armor tile / cooling substrate, which is particularly difficult to find, was performed as shown in FIG. As a result, the results shown in Table 3 were obtained.
[0010]
[Table 1]

[0011]
[Table 2]

[0012]
[Table 3]

[0013]
In Table 1, the actual apparatus (inspected object) for ITER (fusion reactor) is placed on the sample holder and sample table of the test room (TNRF-1 and TNRF-2) using the apparatus of FIG. The conditions for irradiation with a neutron flux are shown. Table 2 shows the result of photographing the neutron beam or X-ray transmitted through the object to be inspected using the neutron television camera with a specific photographic film and exposure time in the apparatus of FIG. . In Table 3, the minimum defect size obtained by using neutron radiography (NRG), X-ray method (XRG), thermography method, and ultrasonic method is displayed on the object to be inspected. This shows that the minimum defect size by neutron radiography is the smallest.
[0014]
【The invention's effect】
The present invention enables non-destructive inspection of various brazed parts and multi-layered complex structures. Therefore, non-destructive inspection and in-service inspection of complex structural objects in fusion experimental reactors such as ITER and fusion power reactors. The present invention has a remarkable effect unique to the present invention that it can be carried out and the operation efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of an ITER divertor target plate and a diagram showing an actual machine.
FIG. 2 is a diagram showing a nuclear facility using neutron radiography.
FIG. 3 is a cross-sectional analysis model diagram of a divertor target plate and a diagram showing a possible defect location.

Claims (4)

A non-destructive inspection method for brazing joints of dissimilar materials using neutrons by neutron radiography using low energy neutron beams with excellent transmission power of dissimilar materials and little attenuation by the materials. Non-destructive inspection method for dissimilar material brazing parts of a structure consisting of a three-layer structure of armor tile / brazing joint / cooling substrate (with cooling channel). The method according to claim 1 or 2, for detecting a minute incompletely brazed defect portion of about 0.5 mm in a structural material. The method according to claim 2 or 3, wherein the structural material is an activated structural material.

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