JP3001792B2 - Apparatus and method for soundness inspection of nuclear fuel assembly for nuclear reactor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for performing an inspection for confirming the integrity of a nuclear fuel assembly during transportation of a nuclear fuel assembly for a nuclear reactor from a nuclear fuel processing facility to a nuclear power plant.

[0002]

2. Description of the Related Art As is well known in the art, for example, a nuclear fuel body used in a light water reactor is manufactured at a nuclear fuel processing facility, inspected for shipment, and then housed in a transport container to be used as a truck, trailer, wagon, or the like. Transported to nuclear power plants by means of vehicles such as vehicles or ships.

FIG. 14 shows a nuclear fuel assembly transport sequence showing the above situation in Japan. That is, the first case (Case-1) in which nuclear fuel assemblies are transported from a nuclear fuel processing facility to a nuclear power plant by truck, and transport from a nuclear fuel processing facility to a port by truck, and then a ship is used to transport the nuclear power plant port or nuclear power plant. It shows the second case (Case-2) in which sea transportation is carried out to a port near the power plant port.

FIGS. 15 and 16 show a transportation sequence when a nuclear fuel assembly is transported from an overseas nuclear fuel processing facility to a nuclear power plant in Japan.

FIG. 15 shows a first case (Case-1), in which a nuclear fuel assembly manufactured at an overseas nuclear fuel processing facility is
First, it is stored in a transport container dedicated to land transportation, and the nuclear fuel unit is transported by land from a land transportation container to water, for example, to a transshipment facility for transshipment to a maritime transport container, using trucks or other transportation means. Transport by transport such as trailer or freight car to overseas ports in shipping containers exclusively for marine transportation,
Thereafter, they are loaded at a port and transported by sea to a Japanese power plant port.

FIG. 16 shows a second case (Case-2) in which a nuclear fuel assembly is housed in an amphibious transport container and transported from an overseas nuclear fuel processing facility to an overseas export port using a truck. However, this is the case where the cargo is loaded on a ship at the port and transported to a power station port in Japan.

FIG. 17 shows an example of the configuration of a land transport container used when transporting a nuclear fuel assembly from an overseas fuel processing facility shown in FIG. 15 to a transport container transshipment facility.

As shown in FIG. 17, the land transportation container 1 is roughly divided into an outer container portion 2 and an inner container portion 3, and the outer container portion 3 is configured to include a container main body 2a and an upper lid 2b. . The inner container part 3 is provided with a container main body 3a and a storage door 3b for storing a plurality of nuclear fuel bodies, and the nuclear fuel body is mounted on a support frame (cradle) 4 via a storage platform 5. . The cradle 4 is supported by the outer container body 2a via a plurality of vibration isolating rubbers (rubber pads) 6 in a suspended state (cradle). The vibration during the land transportation is absorbed by the rubber pad 6, and the vibration proof action against the shock vibration and the stationary vibration of the vehicle such as the truck on which the transport container 1 is mounted is performed, so that the soundness of the nuclear fuel body during the transportation is maintained. It is planned.

FIG. 18 illustrates the configuration of a marine transport container used in the case shown in FIG. As shown in FIG. 18, the marine transport container 7 is a main body 7 for storing a nuclear fuel body.
a, skirt support rings 8, 9 as support members for supporting both ends in the axial direction, and skirt support rings 8, 9
9 and drums 10 and 11 that support
These drums 10 and 11 are supported by necessary transportation means and handling equipment via trunnions 12 which are pivot type support members.

[0010] A nuclear fuel basket 13 for accommodating a plurality of nuclear fuel bodies in correct positions is fixed in the main body 7a. The nuclear fuel basket 13 prevents the vibration of the hull during sea transport, the vibration of the trailer or freight car during land transport, and other shocks during container handling and steady-state vibration from being transmitted to the nuclear fuel body. .

FIG. 19 illustrates the configuration of an amphibious transport container used in the transport sequence shown in FIG.

The amphibious transport container 14 has an outer shell 14a.
And an inner trunk 14b provided therein, and a basket 15 housed and fixed in the inner trunk 14b. Between the outer shell 14a and the inner shell 14b,
6 and the shielding member 17 are stored. Basket 15
A cushioning member 18 for preventing vibration during transportation is mounted inside the basket 15 so that a shock from a trailer, a wagon or a hull during transportation by land or sea, and vibration during normal operation can be applied to the basket 15.
It is prevented from being transmitted to the nuclear fuel body 19 held therein.

[0013] In order to confirm the soundness of nuclear fuel during transport and handling of the container, the following confirmation inspection is performed on the nuclear fuel body transported by the transport sequence using the transport container described above. You.

(1) Check the trip state of the ON / OFF accelerometer attached to the transport container (the accelerometer operates and becomes tripped when a transient impact acceleration exceeding a specified value is applied). (2) Conduct an appearance inspection of the nuclear fuel assemblies removed from the transport container inside the reactor building.

[0015] The above two verification tests are carried out to confirm that there is no problem in the soundness of the nuclear fuel body during transportation and handling of the nuclear fuel body, and to make a guarantee.

If the ON / OFF accelerometer attached to the transport container trips during the confirmation inspection after the transportation, the complete transport container (including the nuclear fuel body) is transported to the nuclear fuel processing facility. Returned to and transported.

FIG. 20 schematically shows a configuration of a general ON / OFF accelerometer. In the ON / OFF accelerometer 20, when an acceleration equal to or more than a certain value is applied to the mass 21, the spring 22 supporting the mass 21 bends, and the pin 23 attached to the tip of the mass 21 moves downward. The pedestal 25 moves laterally with the stopper of the upper spring 24 disengaged, causing a trip state.

Such an ON / OFF accelerometer is usually mounted on a vibration isolating system of each transport container in order to properly grasp the acceleration during handling and transport of the transport container.

FIG. 21 exemplifies a mounting position of an ON / OFF accelerometer on a land transport container. That is, ON
The / OFF accelerometer 20 is attached via a fastener such as a bolt to both end positions, which are rigid portions on the support end side of the cradle 4.

FIGS. 22 and 23 show the structure of a nuclear fuel assembly used in a boiling water nuclear power plant as a typical example of nuclear fuel assemblies to be transported.

The nuclear fuel assemblies 19 are arranged in an 8 × 8 grid.
It has zero nuclear fuel rods 26 and a water rod 27 arranged at the center thereof. The upper and lower ends of the nuclear fuel rods 26 are supported by an upper tie plate 28 and a lower tie plate 29, respectively, and are bundled in a grid by a plurality of, for example, seven spacers 30 arranged at intervals in the axial direction.

The nuclear fuel rod 26 has a cladding tube 26a loaded with a nuclear fuel material such as UO ₂ pellet 31 or MOX pellet (mixed oxide pellet) 32. The nuclear fuel rod 26 and the spacer spring 33 of the spacer 30 are loaded.
Are in contact with each other as shown in FIG.

[0023]

The above-mentioned nuclear fuel body 19
The following are examples of events that may damage the soundness during transportation and handling.

(1) Cracking or chipping of the UO ₂ pellet 31 or MOX pellet 32. (2) Damage to nuclear fuel components such as the spacer 30. The causes of these (1) and (2) may occur when an intermittent impact acceleration of a certain value or more and a steady continuous acceleration of a certain value or more are applied during handling and transport of the nuclear fuel body 19. .

(3) Fretting flaws are generated on the surface of the cladding tube 26a of the fuel rod 26. The fretting flaw is a flaw generated on the surface of the cladding tube 26a due to the friction between the spacer spring 33 and the nuclear fuel rod 26 due to vibration during transportation. The fretting flaw increases when an impact acceleration of a certain value or more is intermittently applied during the transportation of the nuclear fuel body 19 or a steady continuous acceleration of a certain value or more is applied.

The nuclear fuel body 19 of the above (1) to (3)
In the case of directly inspecting whether or not damage has occurred, it should be possible to disassemble the nuclear fuel body 19 after transport and carry out a detailed inspection. It is located in a relocation facility or a nuclear power plant at the final destination and cannot be dismantled.

For this reason, it is practically difficult to directly inspect the fuel integrity after transportation.
As shown in the figure, the ON / OFF accelerometer 20 is attached to the cradle 4 or the like of the land transportation container 1 and the transient impact acceleration applied to the container 1 during the handling and transportation is equal to or more than a fixed value, and the ON / OFF acceleration is measured. Means such as capturing by determining based on a total of 20 trip states are adopted.

However, with this means, acceleration data cannot be continuously collected, and the ON / OFF accelerometer 20 is tripped by a one-time (transient) impact acceleration exceeding a specified value. The following problems have occurred.

(1) There is no means for confirming the cause of the impact acceleration when the ON / OFF accelerometer 20 trips. That is, it is not possible to discriminate whether the container is being handled or being transported. In addition, it cannot be distinguished whether it is a mere transient acceleration or an intermittent or continuous acceleration state during transportation.

(2) Since the intermittent and continuous occurrence acceleration cannot be caught, abnormal states of the vibration system and the securing state of the transport container cannot be confirmed. In other words, the transport container anti-vibration rubber, etc.
Abnormal conditions such as deterioration and breakage of the vibration isolation system cannot be confirmed for each transportation. Further, an abnormal state such as breakage of a suspension of a vehicle such as a truck as a transportation means cannot be confirmed every transportation. Furthermore, it is not possible to check for an abnormality in the securing state between the transport container and the transport means every transport.

For this reason, it is not possible to accurately judge an event that occurs at the time of transporting the nuclear fuel assembly and impairs the soundness of the nuclear fuel assembly for each transport. Therefore, (a) Since it is not possible to accurately judge an occurrence event that impairs the soundness of the nuclear fuel assembly, the original non-defective nuclear fuel assembly can be returned to the nuclear fuel assembly as a defect only by a single one-time transient impact acceleration trip. It may be uneconomical to return to the processing facility and perform a detailed inspection. (B) Due to an abnormality in the vibration isolation system of the transport container, an acceleration value equal to or less than the trip set value of the ON / OFF accelerometer is generated intermittently or continuously, and the influence on the fuel integrity is increased (for example, the amount of fretting) Is increased), it is conceivable that the nuclear fuel body may be received as an acceptable product because the ON / OFF acceleration does not trip.

Then, since such a problem is caused by using the ON / OFF accelerometer,
Use other inspection means instead of ON / OFF accelerometer,
It is conceivable to collect and use continuous generated acceleration.

FIG. 24 exemplifies an inspection means conventionally used in a preliminary confirmation transportation test using a simulated fuel body. Note that the inspection means shown in FIG. 24 is not applied to the transportation of genuine (real) nuclear fuel assemblies. That is, conventionally, in a preliminary confirmation transportation test (preliminary test) using a simulated fuel body, acceleration data was collected using a large-scale inspection means as shown in FIG. However, at the time of actual transportation for transporting a real nuclear fuel assembly, it was very difficult to attach the above-described large-scale inspection means at each transportation stopover every time. Therefore, attaching an acceleration sensor to the nuclear fuel assembly has been performed. Absent. Therefore, at the time of actual transportation, no continuous sampling of the acceleration and its frequency data has been performed.

In the example of FIG. 24, a small acceleration sensor 34
Is fixed with an adhesive or the like to the vibration isolating system of the container or a place where vibration data is required.
Amplifier 36 and large data recorder 37 via
Is connected. Reference numeral 38 denotes a power supply of the distortion amplifier 36. In this device, the acceleration detected by the acceleration sensor 34 is amplified by the distortion amplifier 36, and the data is collected by the data recorder 37.

The collected data, that is, the reproduced signal is an analog signal, and a digital recorder requires a large recorder processing unit 39, and a pen recorder 40 for outputting waveform data as necessary. Required.

However, when such an inspection means is applied to ordinary transport of nuclear fuel bodies, the following problems occur. (A ') Since the whole system becomes large, it is difficult to load the data recorder 37 on the transportation means (truck, trailer, etc.). (B ') The data recorder 37 requires a large-capacity power supply 38, the data recording time is short, and it is necessary to stop at regular intervals and replace the recording tape. (C ') In order to analyze and evaluate the post-transportation acceleration data, it is necessary to take out a recording tape from the data recorder 37, insert the recording tape into a large recorder processing device 39, and perform an analysis operation. It is difficult to perform data processing quickly. (D ') Since the acceleration sensor 34 and the recorder data 37 are connected by the cord 35, it is necessary to turn the cord 35 to the place where the data recorder 37 is installed. Is complicated. Further, in the case of the long code as described above, the noise of the detection signal is easily spread, and there is a problem that the accuracy of the stored data necessarily decreases.

The present invention has been made in view of such circumstances, and it is an object of the present invention to measure the continuous acceleration generated during the steady state or the impact acceleration generated intermittently during the handling and transportation of a shipping container. By outputting in a sequential manner, it is possible to accurately determine the generation state of the acceleration by distinguishing between the transient generated acceleration and the continuous generated acceleration, and also determine the change state of the generated acceleration value in a graph. It is an object of the present invention to provide an apparatus and a method for inspecting the soundness of a nuclear fuel assembly for a nuclear reactor, which can more accurately determine the presence or absence of damage to the nuclear fuel assembly during transportation and, moreover, perform a soundness check.

[0038]

In order to achieve the above-mentioned object, a soundness inspection apparatus for a nuclear fuel assembly for a nuclear reactor according to the present invention includes a nuclear fuel assembly for a nuclear reactor in a transport container from a nuclear fuel processing facility to a nuclear power plant. An inspection apparatus for performing a soundness check of the nuclear fuel body with respect to acceleration when accommodating and transporting, and continuously detects an acceleration generated in the transport container during transport and a waveform thereof, and obtains acceleration data. Detection means for outputting a signal, storage means for continuously recording the peak value and waveform data of the acceleration applied to the transport container based on the output signal from the detection means, and analyzing the data of the storage means, Determining means for confirming and inspecting the soundness of the nuclear fuel body during transportation based on the result, wherein the determining means analyzes the stored acceleration data and permits the analysis result. Characterized by comprising a display panel for displaying the limit value as an image.

In the above-mentioned soundness inspection apparatus, the transport container is a land container having a vibration isolating system, and the vibration isolating system of the land transport container is provided with detection means, and storage means is provided outside the land transport container. And these means are connected by a low noise cable.

Further, in the above-mentioned soundness inspection apparatus, the transport container is a waterborne transport container, and a detecting means is provided on an outer wall of the waterborne transport container or a nuclear fuel body support portion, and a storage means is provided on the outer wall of the waterborne transport container or on the ship. And these two means are connected by a low noise cable.

In the above-mentioned soundness inspection apparatus, the transport container is an amphibious transport container having a basket for accommodating a nuclear fuel body, and a detection means is provided in the basket of the amphibious transport container, and the outer wall of the amphibious transport container is provided. Is provided with a storage means, and these two means are connected by a low noise cable.

Further, in the method for inspecting the soundness of a nuclear fuel assembly according to the present invention, when the nuclear fuel assembly for a nuclear reactor is transported from a nuclear fuel processing facility to a nuclear power plant in a transport container, the nuclear fuel assembly with respect to the acceleration is measured. An inspection method for performing a soundness inspection, comprising: a step of continuously detecting an acceleration applied to the transport container and a waveform thereof during transport or handling of the transport container containing the nuclear fuel; and Storing the acceleration data and the waveform data continuously by a storage means, connecting a computer having a display panel to the storage means immediately after transporting the transport container, and executing data processing by the computer. The analysis results of the stored data and the permissible limit values for the analysis results are displayed on a computer display panel as images. And confirming that the analysis result displayed as an image on the display panel of the computer is within the above-mentioned permissible limit value, so that the acceleration applied to the nuclear fuel body during transportation or handling of the transport container can be reduced. Inspecting and determining the soundness of the nuclear fuel assembly.

It is preferable that the analysis result of the stored acceleration data is displayed as a sequence of generated acceleration times, a generated acceleration frequency distribution, a waveform processing analysis, or an image showing the relationship between acceleration and frequency.

[0044]

According to the soundness inspection apparatus and the soundness inspection method for a nuclear fuel body for a nuclear reactor according to the present invention,
The acceleration generated in the shipping container and its waveform are continuously detected by the detecting means, and the peak value and the waveform data of the acceleration applied to the shipping container are continuously recorded in the recording means. A screen display or the like is performed, and a soundness check of the transported nuclear fuel assembly is performed based on these. Examples of images of the peak value and the waveform data are shown in FIGS.

FIG. 3 shows, in a time-series manner, the acceleration generated from the start to the completion of handling and transportation of the transport container, wherein the horizontal axis represents time, and the vertical axis represents the acceleration value. This time-series display allows the maximum acceleration occurring during handling and transport of the shipping container to be determined, so the occurrence event of the maximum occurrence acceleration can be estimated, and the occurrence acceleration value and the occurrence acceleration exceeding the specified value are transient. It is possible to determine whether the event is an event or a continuity event. That is, it is possible to confirm and determine the transport condition and transport conditions of the transport container to which the acceleration is applied.

FIG. 4 is an example of an image displaying the frequency distribution of acceleration generated during handling and transportation of the transport container. With this frequency distribution, the situation of the frequency distribution of the generated acceleration equal to or higher than the specified value can be grasped, and it is possible to determine whether the generated acceleration is transient or continuous.

FIG. 5 is an example of an image displaying the frequency distribution of acceleration generated during handling and transportation of the transport container. With this frequency distribution, the situation of the frequency distribution of the generated acceleration equal to or higher than the specified value can be grasped, and it is possible to determine whether the generated acceleration is transient or continuous.

FIG. 6 is an example of an image displaying the analysis result of the power spectrum density (PSD) at the maximum acceleration. It is possible to determine whether or not an abnormality has occurred in securing the vibration system and the transport container to the truck or the like.

As described above, by judging whether or not the peak value of the acceleration is within a certain range (permissible range), it is possible to recognize the occurrence of the acceleration that impairs the soundness of the nuclear fuel body, and to determine the acceleration based on the waveform. By taking into account the continuity, intermittentness, and other judgments, it is possible to properly carry out an inspection for confirming the soundness of the nuclear fuel assembly.

In particular, according to the ninth to eleventh aspects of the present invention, accurate and highly accurate determination can be made when the transport container is a land transport container, a water transport container or an amphibious transport container.

[0051]

An embodiment of the present invention will be described below with reference to the drawings.

This embodiment is an example of application to the transport sequence Case-1 shown in FIG. 15, that is, transporting from an overseas fuel processing facility to a transshipment transshipment facility using a land transport container, and then transporting. This is for the case of using a water transport container from a container transshipment facility to a power station port and a reactor building in Japan.

FIG. 1 shows a basic configuration of an inspection apparatus according to this embodiment.

As shown in FIG. 1, the inspection apparatus (impulse memoizer: hereinafter, abbreviated as IM) 42 includes an IM sensor block 43 serving as detecting means for capturing generated acceleration and waveform data, and collects acceleration data. And an IM main body 44 as storage means for storing
The sensor block 43 and the IM main body 44 are connected to each other via the hermetic relay connector 45 and have low-noise cables 46 and 47.
Connected by

X, Y, Z
The three-axis sensors 43a, 43b, and 43c are built in, and the outer shape of the IM sensor block 43 is 104 mm × 92 mm.
The size is 50 mm and the weight is about 1.5 kg.

The shape of the IM body 44 is 240 mm ×
It is 100 mm x 45 mm and weighs about 2 kg.

The IM 42 is attached to the transport container, and a computer 48 is connected to the IM main body 44 after the transportation, so that the peak value G of the continuously generated acceleration and the waveform data of the continuous acceleration taken in the IM main body 44 are obtained. Data processing is performed, and output is performed on the screen of the computer 48. As the computer 48 used for the data processing, a portable small personal computer is sufficient as long as the computer has a sufficient data reproduction capacity, data processing capability, and a function of visually displaying processed data. It can be suitably used.

In this embodiment, the collection and storage contents of the acceleration and waveform data of the IM system include 100,000 peak values g for each axis (X, Y, Z directions) and 5
512 waveform data composed of 12 points are included (8192 waveform data composed of 2048 points are included in an IM system using only waveform data).

FIG. 2 shows a system configuration of the land transportation container 1 used for land transportation along the transportation sequence shown in FIG. 15 and the IM 42 attached to the land transportation container 1.

The IM sensor block 43 is the land transport container 1
Is attached to the cradle 4 by a plurality of fasteners such as bolts. The mounting location is not particularly limited as long as the location is a rigid portion of the main body of the cradle 4 and does not contact the storage door, but as shown in FIG. It is desirable to have a rear end portion along (a).

The IM main body 44 is attached to the outer container main body 2a by a plurality of fasteners such as bolts. As shown in the figure, the mounting location is a concave portion 49 formed outside the outer container main body 2a.
Of the outer container body 2a from the outer surface and the degree of exposure are set small.

The IM sensor block 43 and the IM main body 44 are connected by low noise cables 46 and 47, and the data collected by the IM sensor block 43 is transmitted to the IM main body 44 via the low noise cables 46 and 47. .

All operations of the IM system are performed by operating the IM main body 44.
N, the acceleration applied to cradle 4 during transportation is I
It is caught by the M sensor block 43. This allows
The operation of the IM system is performed by using the nuclear fuel
Can be started at any time after storing in a container.

Therefore, it is possible to continuously collect and store acceleration data generated during a series of container handling operations from the start of storage of the nuclear fuel body 19 before transportation, and to continuously collect acceleration data during transportation. And can be memorized.

Since land transportation is generally short, I
The power source used in the M system is sufficient for the internal power source of the land transportation container 1, and the power source can be used continuously for usually two to three days.

The destination of land transportation in this embodiment is a transshipment facility for transport containers. In this facility, a land transport container is taken out from a truck and placed at a designated place.

With the land transport container 1 placed in the designated place, the computer 48 is immediately connected to the IM main body 44, and the data recorded in the IM main body 44 as a storage device is collected and processed. You. The computer 48 outputs and displays the display as shown in FIGS. 3 to 6 on a display panel (screen or the like) as an image. Therefore,
Immediately after receiving the transport container, the inspector can inspect the acceleration data received during transport and handling of the transport container on the spot.

The acceleration data displayed as an image on the display panel of the computer 48 is compared with an allowable limit value displayed on the same image to determine whether or not the acceleration actually applied to the shipping container is within an allowable range. It is confirmed. If abnormal data exceeding the permissible limit is displayed on the display panel of the computer 48, the inspector determines that the nuclear fuel body has been damaged by abnormal acceleration, and the soundness of the nuclear fuel body is determined. Denied. On the other hand, if the measured data of the acceleration applied to the transport container is all within the allowable range, it is estimated that the nuclear fuel assembly fuel assembly is not damaged, and the integrity of the nuclear fuel assembly is inspected and guaranteed. .

In this way, it is possible to inspect the soundness of the nuclear fuel body after transportation and handling, that is, to determine the presence or absence of damage. After the above inspection, the nuclear fuel assemblies 19 are stored in the water transport container (sea transport container) in the transshipment facility and mounted on the ship.

FIGS. 7 and 8 show the configuration of the marine transport container 7 and the IM system attached to the marine transport container 7.

As shown in FIGS. 7 and 8, the marine transport container 7 has rigid skirt support rings 8 and 9 at both left and right ends, and one skirt support ring 8 is provided with an IM sensor block 43 and a fastener such as a bolt. It is fixed at.

The IM main body 44 is installed in a cabin or the like in the hull 49 at a place where the operator can easily operate the IM main body 44, and power is supplied to the IM main body 44 from the outside via an external power supply device 50.

The IM sensor block 43 and the IM main body 44 are connected to each other via a low noise cable 46, and acceleration data is continuously collected from the IM sensor block 43 and stored in the IM main body 44. IM body 44
Functions as storage means for recording acceleration data.

Before the departure of the transport ship, the power of the IM main body 44 is turned off.
By setting N, acceleration data generated during marine transportation is collected and stored.

After the sea transportation, the computer 48 is connected to the IM main body 44. All data collection and processing methods are shown in Figure 1.
2 is the same as the IM system attached to the land transportation container 1 shown in FIG.

The difference between the IM system of the marine transport container 7 and the IM system of the land transport container 1 is that in the case of marine transportation,
Usually, a voyage of 30 days to 60 days is required, and the internal power supply of the IM main body 44 cannot cope with the voyage.

The above-mentioned IM system is used for marine transportation by ship. The marine transportation container 7 used in the transportation sequence shown in FIG. 15 uses a trailer or a wagon from a transshipment facility to an overseas shipping port. It will be transported, and handling work before and after transportation will also occur. In this case, the IM sensor 43 and the IM main body 44 are separate bodies,
With the above configuration in which the main body 44 is installed outside the container, handling becomes complicated.

In this embodiment, the IM sensor and the IM main body are integrated with each other as a device suitable for collecting and storing acceleration data generated during container handling work and trailer or wagon transportation in such a case. IM device 51 is also provided.

The integrated IM device 51 includes an IM sensor block mounted on the land transport container 1 and an IM main body 44.
The structure is slightly larger than that of the IM sensor 43 and the IM main body 44 described above,
It is 122 mm x 86 mm, weighs 3 kg, uses an internal power supply, and can be used continuously for 2 to 3 days.

The integrated IM device 51 is fixed to the other skirt support ring 9 with fastening bolts or the like. And
For example, as shown in FIG. 9, the inspection is performed at the time of transshipment to a vehicle such as a trailer and transportation.

That is, after storing the nuclear fuel assembly 19 in the marine transport container 7, data collection is started by turning on a switch attached to the integrated IM device 51. After the marine transport container 7 is secured to a designated place in the ship, the switch of the integrated IM device 51 is turned off, and a series of handling operations of the marine transport container and the acceleration data generated during the transportation of the trailer or the wagon are performed. Collection and storage in the IM main body 44 are performed. That is, after data collection, the IM device 51
Is connected to a computer 48, and data collection, processing, and the like are performed in substantially the same manner as the IM system attached to the land transport container 1.

According to the above embodiment, the acceleration data collected by the IM system attached to the transport container is processed by connecting the computer 48 to the IM main body 44, and the results are shown in FIGS. As shown in (1), the time series display of acceleration, the acceleration frequency distribution, the waveform state of the maximum acceleration, the power spectrum density of the maximum acceleration value, and the like are output on the screen of the computer 48.

Based on the output result on the screen, it is determined that there is no problem in the soundness of the nuclear fuel body at the time of transportation of the transported nuclear fuel body 19 and at the time of handling in the container.
Implemented in the system. The criterion for determining the soundness differs depending on the transport experiment of the nuclear fuel assembly, that is, the actual data amount and the evaluation result of the generated acceleration obtained and accumulated by the IM system or the like.

Nuclear fuel body 1 by the IM system of this embodiment
9, the method of determining soundness during transportation and handling,
This will be described with reference to FIGS.

FIG. 10 is a diagram showing a judgment result of a time series display of the generated acceleration. The vertical axis represents the magnitude of the generated acceleration, and the horizontal axis represents the entire transportation time zone (from the start to the completion of transportation).

That is, FIG. 10 is a diagram showing the generated acceleration time-sequence display in which the acceleration transmitted to the vibration isolating system of the transport container during transportation and handling is displayed over time.

The acceleration transmitted to the vibration isolation system of the transport container is
It is transmitted to the nuclear fuel body shown in FIG. 22 as it is. Therefore, when the acceleration exceeding a certain value is transmitted to the nuclear fuel body, the spacers 30 and the fuel rods 2 which are components of the nuclear fuel body are transmitted.
Affects the soundness of the pellets 31 and 32 in 6,
In particular, the quality of the nuclear fuel itself deteriorates significantly.

In abnormal handling of the transport container, such as hanging the transport container on the floor or installing the transport container, impact acceleration acts on the transport container only once or several times. These impact accelerations are detected by IM.

Also, during land transportation using trucks and trailers, the magnitude of the acceleration transmitted to the transport container greatly varies depending on the road surface condition of the transport road. That is, when the road surface is smooth and in a normal state, a relatively small steady acceleration is continuously generated. On the other hand, poor road conditions, trailers crossing railway crossings,
When an unsteady operation such as riding on a convex portion of a road surface or suddenly stopping is performed, a large shocking acceleration is intermittently applied to the transport container.

In such a situation, the device of this embodiment, I
M detects the impact acceleration generated at the time of abnormal handling of the transport container, the continuous steady acceleration during transport operation, and the intermittent impact acceleration, together with their occurrence times. FIG. 10 shows the results of outputting these acceleration data and conditions as images on the display panel of the computer as images.
It is.

The state of the generated acceleration applied to the nuclear fuel assembly can be determined from the output result shown in FIG. 10. If the generated acceleration exceeds a predetermined value (allowable limit value), the state of the nuclear fuel assembly is determined. The soundness is greatly affected, and it is determined that the deterioration of the transport product has progressed.

The hatched area in FIG. 10 indicates the rejected range. If the generated acceleration falls within the hatched area, the transported nuclear fuel body is a target for defective product treatment.

FIG. 11 is a diagram for judging the frequency distribution result of the generated acceleration. The vertical axis represents the frequency of acceleration generated during the transportation time zone, and the horizontal axis represents the magnitude of the generated acceleration. The left and right ends of the graph in FIG.
In this figure, the hatched portion indicates the reject range, and if the bar graph falls within the hatched range, the transported nuclear fuel assembly is treated as a defective product.

That is, FIG. 11 is a generated acceleration frequency distribution determination diagram in which the number of occurrences (frequency) of the generated acceleration shown in FIG. 10 is graphed for each acceleration value. The relatively small acceleration distributed in the center of FIG. 11 has little effect on the fuel body. However, when the frequency of occurrence of a relatively large acceleration distributed on the surface side in FIG. 11 increases, the vibration energy due to the acceleration naturally increases, which affects the soundness of the fuel assembly.

Here, the absolute value of the continuous steady-state acceleration is small, but the occurrence frequency is high. On the other hand, the intermittent impact acceleration has a large absolute value but a low occurrence frequency. Therefore, the vibration energy that affects the soundness of the fuel body needs to be examined from both the acceleration value and the frequency of occurrence.

Therefore, as shown in FIG. 11, when setting the rejection range (non-permissible region), it is necessary to divide the steady-state acceleration and the impact acceleration and determine the allowable number of occurrences for each.

When the frequency of occurrence of each acceleration exceeds a predetermined number, it is considered that the acceleration has greatly affected the soundness of the fuel body, and that the deterioration of the transport product has occurred. Is determined.

FIG. 12 is a diagram showing a waveform processing (PSD: power spectrum density) analysis result of acceleration generated during transportation. The vertical axis shows the power spectrum density (PSD: unit g ² /
Hz), and the horizontal axis represents frequency (Hz).

That is, FIG. 12 shows output results obtained by analyzing the waveforms of all the accelerations shown in FIG. 10 by fast Fourier transform (FFT), and shows the frequency and the spectral density (g ²
/ Hz). Here, the spectral density (g ² / Hz) indicates the magnitude of vibration energy.

In particular, during transportation, the fuel body resonates in a frequency range exceeding a predetermined value. Therefore, when an acceleration having a large spectral density is transmitted within the range of the resonance frequency, the fuel body resonates, and at the same time, the fuel rods and the spacer ring vibrate, thereby causing fretting damage and the like. It will seriously affect the health of the fuel assembly.

Therefore, as a means for confirming whether or not the above-mentioned damage has occurred in the fuel body, a reject range (non-permissible range) for the power spectral density (PSD) is set as shown in FIG. There is a need to.

The hatched portion indicates the rejected range. If the result of waveform processing by the computer, that is, if the waveform example in FIG. 12 falls in the rejected range, the transported nuclear fuel assembly is treated as a defective product.

FIG. 13 is a diagram showing a waveform processing (g-Hz) analysis result determination diagram. The vertical axis represents the magnitude of the generated acceleration, and the horizontal axis represents the frequency of the generated acceleration. The black dot (•) indicates the relationship between the acceleration of the generated acceleration during transportation and the frequency. If the black dot (•) falls within the rejected range of the shaded area, the transported nuclear fuel body is treated as a defective product. Becomes

The final judgment for rejecting the transported nuclear fuel assembly and returning it to the nuclear fuel processing facility is shown in FIG.
This is performed based on the comprehensive determination result of FIG.

The present invention is not limited to the above embodiment, but can be applied to the amphibious transport container 14 shown in FIG. That is, acceleration data with the IM sensor block 43 and the IM main body 44 attached can be collected. In this case, the integrated IM device 51 can be attached to the outer shell 14a in FIG.

Further, the IM sensor block of the present invention is mounted on the nuclear fuel basket 13 of the marine transport container 7 shown in FIG. 18 or the basket 15 of the amphibious transport container 14 shown in FIG. It is also possible to collect basket vibration data inside.

In the above embodiments, various judgment diagrams obtained by analyzing the acceleration data and the like added to the transport container are as follows.
This is extremely important information when judging the state of quality deterioration of nuclear fuel assemblies. However, the inspection apparatus and the inspection method according to each embodiment are not limited to the above-described applications, and can be applied to, for example, abnormality detection of a transportation means itself such as a truck or a vibration isolation system of a transportation container. It is also possible to detect an abnormality specific to itself or the vibration isolation system. For example, when transportation is performed while an abnormality occurs in a truck suspension, a result different from the determination result at the time of normal operation shown in FIGS. 10 to 12 is obtained. Therefore, the abnormality of the transportation means itself can be detected by comparing with the determination result at the time of normal operation, and the trouble occurrence at the next transportation can be effectively prevented by solving the abnormality specific to the transportation means in advance. be able to.

[0108]

As described in detail in the above embodiment, according to the present invention, the continuous acceleration generated during the steady state or the impact acceleration generated intermittently during the handling and transportation of the shipping container is measured. By outputting in a sequential manner, it is possible to distinguish between the transient maximum acceleration and the continuous generated acceleration, and it is possible to accurately judge the state of occurrence of the acceleration, and the change state of the value of the generated acceleration is also displayed in a graph. You can judge. Therefore, it is possible to more accurately determine whether or not the nuclear fuel body has been damaged during transportation, and to perform a soundness confirmation test.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of an inspection apparatus according to the present invention.

FIG. 2 is a diagram showing a state in which the apparatus is mounted in the embodiment.

FIG. 3 is a diagram showing an example of an image of acceleration time series display according to the present invention.

FIG. 4 is a diagram showing an image example of an acceleration frequency distribution according to the present invention.

FIG. 5 is a diagram showing an example of an image of a waveform of an acceleration according to the present invention.

FIG. 6 is a diagram showing an example of an image of a power spectrum density at a maximum acceleration according to the present invention.

FIG. 7 is a diagram showing an example of mounting a water (sea) transport container in the embodiment.

FIG. 8 is an enlarged view of a main part of FIG. 7;

FIG. 9 is a view showing a land transportation state in the embodiment.

FIG. 10 is a diagram showing a display of a time series of generated acceleration in the embodiment.

FIG. 11 is an acceleration frequency distribution determination diagram in the embodiment.

FIG. 12 is a waveform processing analysis result determination diagram in the embodiment.

FIG. 13 is a view showing a waveform processing analysis result judgment in the embodiment.

FIG. 14 is a diagram showing an example of a transport sequence of a nuclear fuel assembly.

FIG. 15 is a diagram showing another example of the transport sequence of the nuclear fuel assembly.

FIG. 16 is a view showing still another example of the transport sequence of the nuclear fuel assembly.

FIG. 17 is a configuration diagram showing a land transportation container.

FIG. 18 is a configuration diagram showing a water (sea) transport container.

FIG. 19 is a configuration diagram showing an amphibious transport container.

FIG. 20 is a configuration diagram showing an ON / OFF accelerometer.

FIG. 21 is a diagram showing a state where an accelerometer is attached to a land transportation container.

FIG. 22 is an overall view showing a nuclear fuel assembly.

FIG. 23 is a partially enlarged view showing a nuclear fuel assembly.

FIG. 24 is a diagram showing a conventional acceleration data collection system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Land transport container 2 Outer container part 2a Container main body 2b Top lid 3 Inner container part 3a Container main body 3b Storage door 4 Support frame (cradle) 5 Storage platform 6 Rubber pad 7 Marine transport container 7a Main body 8,9 Skirt support ring 10,11 Drum 12 trunnion 13 nuclear fuel basket 14 amphibious transport container 14a outer shell 14b inner shell 15 basket 16 cushioning material 17 shielding material 18 buffering material 19 nuclear fuel body 20 ON / OFF accelerometer 21 mass 22 spring 23 pin 24 upper spring 25 pedestal 26 Nuclear fuel rod 27 Water rod 28 Upper tie plate 29 Lower tie plate 30 Spacer 26a Cladding tube 31 UO ₂ pellet 32 MOX pellet (mixed oxide pellet) 33 Spacer spring 34 Acceleration sensor 35 Code 36 Distortion amplifier 37 Data recorder 38 Power supply 39 Recorder data processing device 40 Pen recorder 42 Inspection device (Impulse memorizer: IM) 43 IM sensor block 44 IM body 45 Hermetic relay connector 46, 47 Low noise cable 48 Computer 49 Recess 50 External power supply 51 Integrated IM device 52 Display panel 53 Image

Claims (18)

(57) [Claims] When a nuclear fuel body for a nuclear reactor is transported in a transport container from a nuclear fuel processing facility to a nuclear power plant,
A testing device for performing a soundness check of the nuclear fuel body with respect to acceleration, a detecting unit that continuously detects acceleration generated in the transport container during transport and a waveform thereof, and outputs a signal of acceleration data, Storage means for continuously recording the peak value and waveform data of the acceleration applied to the transport container based on the output signal from the detection means; and analyzing the data of the storage means, and performing a transport based on the result. Determining means for confirming and inspecting the soundness of the nuclear fuel assembly, wherein the determining means includes a display panel for displaying an analysis result of the stored acceleration data and an allowable limit value for the analysis result as an image. Inspection system for nuclear fuel assemblies for nuclear reactors. 2. The analysis result of the stored acceleration data is:
The nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the image is displayed as an image showing a time series change of the acceleration applied to the transport container. 3. The analysis result of the stored acceleration data is:
2. The nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the image is displayed as an image showing an occurrence frequency distribution of acceleration applied to the transport container. 4. The analysis result of the stored acceleration data is:
2. The apparatus for inspecting the soundness of a nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the result is an analysis result of waveform processing of acceleration applied to the transport container. 5. The nuclear fuel assembly for a nuclear reactor according to claim 4, wherein the result of the acceleration waveform processing analysis is displayed as an image showing the relationship between the power spectrum density and the frequency of the acceleration. . 6. The analysis result of the stored acceleration data is:
The nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the image is displayed as an image indicating a relationship between the magnitude of the acceleration and the frequency. 7. The analysis result of the stored acceleration data is:
2. The nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the image is displayed as an image showing a relationship between the acceleration applied to the transport container and the frequency. 8. An apparatus according to claim 1, wherein said detecting means and said storing means are integrated. 9. The transport container is a land container having a vibration isolating system. The vibration isolating system of the land transport container is provided with a detecting means, and a storage means is provided on an outer wall of the land transport container. 2. The soundness inspection apparatus for a nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the soundness inspection apparatus is connected by a cable. 10. The water transport container is a water transport container, and a detecting means is provided on an outer wall of the water transport container or a nuclear fuel body support portion, and a storage means is provided on the outer wall of the water transport container or on the ship, 2. The integrity inspection system for a nuclear fuel assembly for a nuclear reactor according to claim 1, wherein the integrity inspection system is connected by a low noise cable. 11. The transport container is an amphibious transport container with a basket for containing a nuclear fuel body, wherein a detection means is provided in a basket of the amphibious transport container, and a storage means is provided on an outer wall of the amphibious transport container. 2. The integrity inspection system for a nuclear fuel assembly for a nuclear reactor according to claim 1, wherein said two means are connected by a low noise cable. 12. An inspection method for performing a soundness check of said nuclear fuel assembly with respect to acceleration when storing and transporting the nuclear fuel assembly for a nuclear reactor from a nuclear fuel processing facility to a nuclear power plant in a transport container. A step of continuously detecting an acceleration applied to the transport container and a waveform thereof during transportation or handling of the accommodated transport container, and continuously storing acceleration data and waveform data applied to the transport container by a storage unit And a step of connecting a computer having a display panel to the storage unit immediately after transporting the transport container, executing data processing by the computer, analyzing the stored data, and permitting the analysis result. Displaying the limit values as an image on a computer display panel; and displaying the image on the computer display panel. Checking and judging the soundness of the nuclear fuel assembly with respect to the acceleration applied to the nuclear fuel assembly during transportation or handling of the transport container by confirming that the analysis result displayed is within the allowable limit value. A method for inspecting the soundness of a nuclear fuel assembly for a nuclear reactor, comprising: 13. The nuclear fuel assembly according to claim 12, wherein the analysis result of the stored acceleration data is displayed as an image showing a time series change of the acceleration applied to the transport container. Sex test method. 14. The soundness of a nuclear fuel assembly for a nuclear reactor according to claim 12, wherein the analysis result of the stored acceleration data is displayed as an image showing an occurrence frequency distribution of the acceleration applied to the transport container. Sex test method. 15. The nuclear fuel assembly for a nuclear reactor according to claim 12, wherein the analysis result of the stored acceleration data is a waveform processing analysis result of the acceleration applied to the transport container. 16. The method according to claim 15, wherein the result of the acceleration waveform processing analysis is displayed as an image showing the relationship between the power spectrum density and the frequency of the acceleration. . 17. The method according to claim 12, wherein the analysis result of the stored acceleration data is displayed as an image showing a relationship between the magnitude of the acceleration and the frequency. . 18. The analysis result of the stored acceleration data is displayed as an image showing a relationship between the acceleration applied to the transport container and the frequency.
The method for inspecting the soundness of a nuclear fuel assembly for a nuclear reactor as described above.