JPH0781940B2 - Inpile creep test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an in-pile creep test apparatus for investigating the influence of radiation irradiation in a nuclear reactor on mechanical strength of structural materials and the like. More particularly, the present invention relates to a device that allows a constant load to be stably applied over a long period of time and allows a plurality of test pieces to be arranged in a housing.

(Prior Art) In a conventional in-pile creep testing apparatus, it is usual that a test piece, a driving force source for the test piece, and a strain measuring sensor are installed in close proximity to each other. At that time, a bellows was used as a driving force source for applying a tensile force to the test piece, and the driving force was generated by gas pressurization.

Therefore, the configuration of a conventional in-pile creep test apparatus will be described with reference to FIG. FIG. 3 is a sectional view of the in-pile creep test apparatus, and reference numeral 1 in the drawing is a housing. The housing 1 depends from a shield plug 2 that closes the upper opening of the reactor vessel. A test piece 3 is arranged in the housing 1 and below the housing 1. The lower end of the test piece 3 is fixed to a supporting portion 1a projecting upward from the inner surface of the lower end of the housing 1,
The upper end is fixed to the rod 4. A flange 5 is formed on the upper end of the rod 4 and is connected to the strain detector 6 via the flange 5. A guide plate 7 projects from the housing 1 at a substantially intermediate position of the rod 4, and the rod 4 penetrates the guide plate 7. Between the flange 5 and the guide plate 7 and at the outer peripheral position of the rod 4, there is provided a bellows 8 which forms a pressure receiving chamber 8a inside. A gas pipe 9 is connected to the pressure receiving chamber 8a, and a desired tensile force is applied to the test piece 3 by supplying and discharging gas into the pressure receiving chamber 8a through the gas pipe 9. That is, when the pressurized gas is supplied into the pressure receiving chamber 8a, the pressure acts on the lower surface side of the flange 5 as shown by the arrow in the figure, whereby the tensile force acts on the test piece 3 via the rod 4. . At this time, the bellows 8 keeps the pressure receiving chamber 8a airtight and expands and contracts to allow the rod 4 to move. At that time, when the test piece 3 is deformed, it appears as a displacement of the rod 4, and the strain detector 6
It is measured by. In this way, the load acting on the test piece 3 and the amount of deformation are measured.

The test piece 3 is under the neutron irradiation environment in the reactor, and it is necessary to control the temperature according to the test conditions. Therefore, the heater 10 is arranged on the outer peripheral side of the test piece 3, and the heat insulating material 11 is further installed on the outer peripheral side thereof.

The above configuration has the following problems.

First, in the above-mentioned in-pile creep test, a relatively large load is required as a test load.
The gas pressure acting on the bellows is also high, and it depends on the diameter of the bellows 8, but the pressure is on the order of several + kg / cm ² . Further, since the bellows 8 is arranged in the reactor vessel in the high temperature region together with the test piece 3, a high thermal stress is generated in the bellows 8, and as a result, the bellows 8 also undergoes creep deformation. When such creep deformation occurs, the spring constant of the bellows 8 changes. Therefore, even if a constant gas pressure is applied, the generated force changes with time, and there is a risk that high-precision measurement may be impaired due to the stable addition of a constant load for a long time. On the other hand, it is possible to install a load cell on the rod 4 and control the pressure to keep the load constant, but there is no compact and highly accurate load cell that can withstand use at high temperature for a long time. There is a problem. Therefore, conventionally, a test with low accuracy has been obliged, or a test in which the shape of the test piece 3 is made small to significantly reduce the required load has been forced.

Another problem is that in the conventional configuration, only one test piece 3 can be arranged in the housing 1. That is, when many test pieces 3 are not arranged in the housing 1, it is necessary to reduce the diameter of the bellows 8 provided corresponding to each test piece 3. However, when the diameter of the bellows is reduced, the gas pressure acting on the bellows increases, which may impair the soundness of the bellows 8. Therefore, it has been required to consider a certain means and arrange a plurality of test pieces 3 in the housing 1.
Further, in the conventional apparatus shown in FIG. 3, since the lower end of the test piece 3 is fixed to the bottom of the housing 1, when the test piece 3 is taken out from the reactor vessel, the housing 1 is also taken out from the reactor vessel. It was necessary, and when the housing 1 was taken out of the reactor vessel, the gas in the reactor could leak to the outside.

(Problems to be Solved by the Invention) As described above, according to the conventional configuration, there is a problem that a constant load cannot be applied for a long time and only one test piece can be arranged in the housing. The purpose of this test is to apply a constant tensile load to the test piece over a long period of time, and it is possible to place multiple test pieces in the housing. Another object of the present invention is to provide an in-pile creep test apparatus capable of taking out a test piece from the inside of the reactor vessel without leaking gas inside the reactor vessel to the outside.

[Configuration of the Invention] (Means for Solving the Problems) That is, the in-pile creep test apparatus according to the present invention is inserted into the reactor vessel through a shield plug that closes an upper opening of the reactor vessel. A housing, a casing having a lower end having a connecting portion that is screwed into a connected portion provided on the bottom surface of the housing, and a support portion that fixes the lower end of the test piece housed in the casing to the bottom portion of the casing, A load cell provided outside the reactor vessel and connected to the upper end of the test piece via a connecting rod, and a tensile load applied to the test piece via the load cell and the connecting rod provided outside the reactor vessel. And a strain detector for detecting the axial elongation of the test piece.

(Operation) In other words, by installing a device for applying a tensile load to the test piece above the outside of the reactor vessel, use of a device that can provide a high load with high precision, such as a hydraulic or pneumatic cylinder mechanism. This makes it possible to perform highly accurate measurement with a constant tensile load applied in a stable state for a long period of time.

Also, by installing a device for applying a tensile load above the outside of the reactor vessel, there is no need to arrange a relatively large diameter bellows in the vicinity of the test piece as in the conventional case, and as a result, the diameter can be reduced. be able to. Therefore, a plurality of test pieces can be simultaneously arranged in the radial direction for measurement. Further, by releasing the screwed state between the connected portion provided on the bottom surface of the housing and the connecting portion provided on the lower end of the casing, it becomes possible to take out the casing containing the test piece from the reactor vessel, As a result, the test piece can be taken out of the reactor vessel without leaking the gas in the reactor vessel to the outside.

(Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing the overall configuration of the in-pile creep test apparatus according to the present embodiment, in which reference numeral 101 is a housing. The housing 101 is arranged so as to penetrate a shield plug 102 that closes an upper opening of a reactor vessel (not shown).

A plurality of in-pile creep test mechanisms 103 are arranged in the housing 101 (note that only one of them is shown in the figure). The above in-pile creep test mechanism 103
Is a hydraulic cylinder mechanism 104 located above the reactor vessel
And a test piece portion 105 arranged in the housing 101 below the hydraulic cylinder mechanism 104, and a load cell 10 connecting the hydraulic cylinder mechanism 104 and the test piece portion 105.
It is composed of 8, a connecting rod 109, and a connecting pipe 110.

First, the configuration of the hydraulic cylinder mechanism 104 will be described in detail. In the figure, reference numeral 106 is a drive unit housing, and the drive unit housing 106 is connected to the upper end portion of the housing 101. A power cylinder 107 is disposed inside the drive unit housing 106, and below the power cylinder 107, the load cell 108, the connecting rod 109, and the connecting pipe 110.
Are sequentially connected. A pressure generator 111 is installed on the shield plug 102 outside the drive unit housing 106. Pipes 112 and 113 are provided between the pressure generator 111 and the power cylinder 107 to connect the drive unit housing 1 to each other.
It is installed through 06.

The test piece portion 105 is connected below the connection pipe 110. The structure of the test piece portion 105 will be described below with reference to FIG. A fork 114 is connected to the lower end of the connecting pipe 110, and a strain detector 115 is provided at the upper end of the fork 114. A casing 116 is arranged below the fork 114, and the forked members of the fork 114 penetrate the upper side surface of the casing 116,
The base end thereof is a fork end 117 arranged in the casing 116. A rod 118 is connected below the fork end 117, and a test piece is attached to the lower end of the rod 118.
119 are connected. The lower end of the test piece 119 is fixed to a support portion 120 projecting upward from the bottom surface of the casing 116. Further, a heater 121 is provided on the outer peripheral side of the test piece 119.
Is arranged, and the outer peripheral side of the heater 121 is filled with a heat insulating material 122. A bar 123 is connected to the upper end of the casing 116, and the bar 123 is connected to the strain detector 115.

Further, a female screw portion 124 as a connecting portion is formed at the lower end of the casing 117, while a bolt 125 as a connected portion is projected from the bottom surface of the housing 101. The test piece portion 105 is fixed to the housing 101 by screwing the female screw portion 124 and the bolt 125.

Further, in this embodiment, a plurality of in-pile creep test mechanisms 103 having the above-mentioned structure are arranged in the housing 101 in the radial direction. Since this is not a structure that uses a bellows as in the past, it is possible to reduce the diameter of the test piece portion 105, and as a result, it is possible to arrange a plurality of test piece portions 105 in the housing 101. It is a thing.

The operation will be described based on the above configuration. First, a tensile load is applied by the hydraulic cylinder mechanism 104. That is, the hydraulic pressure is supplied from the pressure generator 111 to the power cylinder 107 via the pipes 112 and 113. As a result, a tensile force is generated in the power cylinder 107, and this tensile force is applied to the load cell 108, the connecting rod 109, the connecting pipe 110, and the fork 11.
4, and is transmitted to the test piece 119 via the rod 118. At that time, the pulling force is adjusted by adjusting the fluid pressure from the pressure generator 111 based on the feedback from the load cell of the load cell 108. Also, power cylinder
The upper end of 107 is connected to the drive unit housing 106, so that a tensile load also acts on the drive unit housing 106.

The test piece 119 is elongated in the axial direction by the application of the tensile load, and the elongation is measured by measuring the displacement between the bar 118 and the strain detector 114. Such measurement is performed for all of the in-pile creep test mechanisms 103 arranged in the housing 101.

In addition, regarding the test piece portion 105 for which the test is completed, the female screw portion 1
By releasing the screwing engagement with the 23 and the bolt 124, the test piece portion 105 can be carried out independently of the other test piece portions 105.

According to this embodiment, the following effects can be obtained.

First, a constant tensile load can be applied in a stable state over a long period of time. That is, in the case of the present embodiment, the device for applying a load is arranged outside the reactor vessel in a room temperature atmosphere, and as a result, a stable load and a hydraulic pressure capable of applying a relatively high load stably for a long period of time are provided. This is because the cylinder mechanism 104 can be used. Therefore, highly accurate measurement can be performed.

Next, in the case of the present embodiment, since the bellows is not used in the test piece portion 105 as in the conventional case, the diameter dimension of the test piece portion 105 can be reduced, and as a result, the diameter of the test piece portion 105 can be reduced. A plurality of test piece parts 105 can be installed in the direction. At this time, since the hydraulic cylinder mechanism 104 is also installed corresponding to each row, many measurements can be performed simultaneously.

Next, since the load cell 108 is also placed outside the reactor vessel in a normal temperature atmosphere, a load cell with high accuracy can be used. Therefore, the control of the pulling force based on the signal from the load cell is also highly accurate.

Further, a female screw portion 123 is formed at the lower end of the test piece portion 105, and the female screw portion 123 and the bolt 124 on the housing 101 side are formed.
It can be attached and detached independently of the other test piece part 105 by releasing the screwing with, and the test piece 119 can be taken out from the reactor container without leaking the gas in the reactor container to the outside. It becomes possible.

The present invention is not limited to the above-mentioned embodiment,
Various configurations are conceivable as to how many rows of in-pile creep test devices 103 are arranged in the housing or how many test strip portions 105 are arranged in each row.

Next, a second embodiment will be described. That is, in the first embodiment, each in-pile creep test mechanism 103 was provided with one test piece portion 105, but a plurality of test piece portions 105 were provided.
May be arranged in series. That is, considering the case of connecting another test piece portion 105 below the test piece portion 105 shown in FIG. 2, first, a short connecting pipe is connected to the lower end of the casing 116, and the lower portion of this connecting pipe is connected. The test piece portion having the same structure as the test piece portion 105 shown in FIG. Then, the casing 116 of the test strip portion 105 located at the lowermost end where the plurality of test strip portions 105 are connected is fixed to the bottom surface of the housing 101. Therefore, the tensile load applied from the hydraulic cylinder mechanism 104 arranged at the upper end is transmitted to all the test piece parts 105 arranged in series,
Therefore, a tensile test can be performed on a plurality of test pieces 119 at the same time. Further, the displacement generated in each test piece 119 is individually measured by the strain detector 115 corresponding to each test piece 119. Further, if any test piece 119 breaks, the load is transmitted between the stopper 116a at the upper end of the casing 116 and the fork end 117, and as a result, the casing 116 is broken.
Load will be transmitted to the other side, and
The test for 9 will continue.

As described above, in the case of the second embodiment as well, it is possible to obtain the same effects as in the case of the first embodiment, and it is possible to simultaneously measure more test pieces 119.

The present invention is not limited to the first and second embodiments, and the number of in-pile creep test mechanisms arranged in the housing or the number of test piece parts in each in-pile creep test mechanism are not limited. The number of joints to be connected is arbitrary. Further, the device for generating the tensile force is not limited to the hydraulic cylinder mechanism, and may be, for example, pneumatic pressure or hydraulic pressure.

[Effects of the Invention] As described in detail above, according to the present invention, a constant tensile load can be stably applied to a test piece for a long period of time, and a plurality of test pieces can be arranged in a housing. Further, it is possible to provide an in-pile creep test apparatus capable of taking out a test piece from the inside of the reactor vessel without leaking the gas inside the reactor vessel to the outside.

[Brief description of drawings]

1 and 2 are views showing an embodiment of the present invention.
FIG. 1 is a sectional view showing the overall structure of an in-pile creep test apparatus, FIG. 2 is a sectional view showing the structure of a test piece portion, and FIG. 3 is a sectional view showing the structure of a conventional in-pile creep test apparatus. 102 …… Shield plug that closes the upper opening of the reactor vessel, 1
19 …… Test piece, 104 …… Hydraulic cylinder mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Shoji 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Headquarters office (56) References

Claims (1)

[Claims] 1. A method for measuring the mechanical strength of a test piece placed in a reactor vessel, wherein the reactor vessel is penetrated through a shield plug (102) closing an upper opening of the reactor vessel. A casing (116) having a housing (101) inserted therein and a connecting portion (124) screwed to a connected portion (125) provided on the bottom surface of the housing (101) at the lower end.
And the test piece (11
A support part (120) for fixing the lower end of 9) to the bottom part of the casing (116) is connected to the upper end of the test piece (119) provided outside the reactor vessel via a connecting rod (109). A load cell (108), means (107) provided outside the reactor vessel for applying a tensile load to the test piece (119) via the load cell (108) and the connecting rod (109), An in-pile creep test apparatus comprising: a strain detector (115) for detecting the axial elongation of the test piece (119).