JPH0434710B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an automatic fuel exchange device, and in particular, it can identify the identification number of a fuel assembly in a nuclear reactor pressure vessel or the like in a short time, and This invention relates to an automatic fuel exchange device suitable for reliably exchanging fuel.

[Background of the invention]

A device for visualizing identification numbers of fuel assemblies using ultrasonic waves has already been proposed in Japanese Patent Application Laid-open No. 87898/1983. This device images objects inside a nuclear reactor, and in order to obtain detailed images, it is necessary to drive and scan the probe. Therefore, a scanning mechanism for the probe is required, and it is difficult to insert the probe into narrow areas. Another problem is that it takes a long time to obtain an image. In particular, in the case of fast breeder reactors, sodium is used as a coolant, so the fewer mechanical parts inserted into the sodium, the longer the life of the equipment and the higher the reliability, but the drawback is that it is difficult to do so. There is.

[Purpose of the invention]

The present invention has been made in view of the above, and its purpose is to be able to identify the identification number of a fuel assembly in a short time, and to ensure automatic replacement of a designated fuel assembly. An object of the present invention is to provide an automatic fuel exchange device.

[Summary of the invention]

In order to achieve the above object, the present invention is configured as follows.

That is, a pulling mechanism that grips the gripping portion of the fuel assembly and pulls up the fuel assembly, a moving mechanism that moves the lifting mechanism to a designated position, and a drive control device that drives and controls the lifting mechanism and the moving mechanism. A fuel exchange device comprising: a plurality of ultrasonic probes arranged on a two-dimensional surface at the tip of the pulling mechanism to form a two-dimensional array probe; an ultrasonic probe driving means for simultaneously applying a pulse voltage for generating ultrasonic waves to each of the ultrasonic probes; a transmission/reception control means for controlling ultrasonic transmission and reception of the two-dimensional array probe; Phase difference distribution of reflected waves received on the surface of the two-dimensional array probe when ultrasonic waves are simultaneously transmitted from the two-dimensional array probe toward the identification number engraved on the fuel assembly by transmission/reception control. The apparatus includes identification number discriminating means for determining an identification number by determining a pattern and comparing the determined reflected wave phase difference distribution pattern with data related to the phase difference distribution pattern for determination.

By ultrasonic transmission control, ultrasonic waves are simultaneously transmitted from each ultrasonic probe of the two-dimensional array probe to the identification number of the fuel assembly at the specified position via the ultrasonic probe drive means. , a reflected wave phase difference distribution pattern unique to the identification number is formed on the surface of the two-dimensional array probe.

In other words, the receiving surface of each ultrasound probe receives reflected waves of ultrasound emitted by itself and scattered reflected waves of ultrasound emitted from other ultrasound probes. Waves formed by interference belong to either a positive or negative phase difference, and as a result, the two-dimensional array probe has a group of ultrasound probes that receive ultrasound waves with a positive phase difference, and a group that receives ultrasound waves with a negative phase difference. The ultrasonic probes are divided into a group of ultrasonic probes that receive phase-difference ultrasonic waves, and each group forms a unique phase-difference distribution pattern according to the identification number. Details are given in the Examples section.

In the present invention, this reflected wave phase difference distribution pattern is captured through processing of the received signal of the reflected wave, and it is determined which identification number pattern this is by using discrimination data related to the phase difference distribution pattern specific to the identification number, which has been investigated in advance. Verify. Therefore, the identification number is determined through simultaneous ultrasonic transmission and reception control from the ultrasonic element group, without mechanically or electrically scanning each ultrasonic probe of the two-dimensional array probe.

In this way, fuel assembly identification and automatic replacement operations are made possible.

[Embodiments of the invention]

The present invention will be described in detail below with reference to the embodiments shown in FIGS. 11 to 14 and 19, as well as FIGS. 1 to 10 and 15 to 18.

First, the principle of the identification number discrimination method used in the present invention will be explained.

FIG. 1 is a diagram showing an example of the arrangement of the grip part and identification number of a fuel assembly. In FIG. 1, 1 is a fuel assembly, and 2 is a grip provided on the top of a container of the fuel assembly 1. An identification number 3 is engraved on the top surface of the grip 2 for identification.

In order to identify this identification number 3 using ultrasonic waves, in the present invention, as shown in FIG. . As shown in the figure, the array probe 4 has a configuration in which a plurality of ultrasound probes are bundled and arranged on a two-dimensional surface, and each small probe transmits ultrasound waves. , and receive reflected waves. When ultrasonic waves are simultaneously emitted from all the probes of the two-dimensional array probe 4, plane waves propagate from the array probes toward the identification number 3 stamped on the upper surface of the grip part 2. And the grip part 2
In the flat portion of the top surface where there is no identification number 3, the ultrasonic waves propagated from the array probe 4 are reflected in the direction of propagation, but in the portion where the identification number 3 is present, the ultrasonic waves are scattered in the same direction. do. Therefore, the ultrasonic waves reflected from the flat part of the grip part 2 and the ultrasonic waves reflected from each part of the identification number 3 are incident on each probe of the array probe 4. . At this time, the signal received by each probe can be expressed mathematically as follows.

FIG. 3 is a diagram schematically showing the geometrical arrangement of the identification number 3 and the array probe 4. If we now focus on the probe 5 of the array probe 4, the probe 5 has a The ultrasonic wave 6 emitted from the probe 5 is reflected by the flat surface of the gripping part 2, and the ultrasonic wave emitted from another probe is reflected at the coordinates (x, y, 0) of the identification number 3. Ultrasonic waves 7 reflected from the position are incident. By the way, if the coordinates of the probe 5 are (x ₀ , y ₀ , z),
The propagation distance l ₀ of the reflected wave 6 is 2z because it is twice the distance between the coordinates (x ₀ , y ₀ , z) and the coordinates (x ₀ , y ₀ , 0). On the other hand, the propagation distance l ₇ of the reflected wave 7 is determined by the coordinates (x,
Since it is the sum of the distance between the coordinates (x, y, 0) and the coordinates (x, y, 0) and the distance between the coordinates (x, y, 0) and the coordinates (x ₀ , y ₀ , z), it is expressed by the following equation.

l ₇ = z + √ ( ₀ -) ² + ( ₀ -) ² + ² ... (1) If the transmitted ultrasonic wave is expressed by the following formula, (t) = e ⁱ 〓 ^t ... (2) Here , t: time i; imaginary number symbol ω: angular velocity, and the reflected wave 6 is a wave in which the transmitted ultrasonic wave propagated by a distance of 2z, so it is expressed by the following equation.

₆ (t)=e ⁱ 〓 ^t-ik2z ...(3) Here, k; wave number If the frequency of ultrasound is f and the speed of sound is v, then the wave number k is k=2πf/v=ω/v... …(4) becomes.

In addition, the reflected wave 7 indicates that the transmitted ultrasonic wave is at a distance l ₇ ((1)
Since it is a wave that has propagated by (see formula), it can be expressed by the following formula.

Now, reflected waves ₆ and ₇ are incident on probe 5, but reflected wave ₇ is a wave reflected from all parts with identification number 3, so the total number of reflected waves incident on probe 5 is Then, can be calculated using the following formula.

Here, C: Ratio of reflectance between reflected wave 7 and reflected wave 6 (x, y, 0); Distribution function that indicates 1 at the coordinates where identification number 3 exists and 0 at the coordinates where it does not exist In equation (6), When z is sufficiently large with respect to x ₀ and y ₀ , that is, when the probe 5 and the grip part 2 are sufficiently far apart compared to the sizes of the array probe 4 and the identification number 3, ( Equation 6) can be approximated as follows.

Here, when calculating the phase difference δ of the wave expressed by equation (7) with respect to the reflected wave 7, in general, the wave e ⁱ 〓 ^t- 〓 and the wave e ⁱ 〓 ^t- 〓
Since the phase difference is expressed as cos(α-β), it is expressed as follows.

δ (x ₀ , y ₀ , z) = cos [∫ ^∞ _-∞ ∫ ^∞ _-∞ (x, y,
0)k{(x ₀ −x) ² +(y ₀ −y) ² }/2zdx・dy……(8
) Here, if (x, y, 0) is represented by the distribution function of the letter A as shown in Figure 4 (the black part corresponds to "1" and the white part corresponds to "0"), then equation (8) can be written. using δ
The value of (x ₀ , y ₀ , z) can be calculated. The phase difference δ is
As shown in FIG. 5, the value is positive in the shaded area 8, and negative in the non-hatched area 9. This phase difference distribution pattern is a unique pattern that differs for each identification number. In the present invention, the identification number is obtained by comparing each phase difference distribution pattern with data for identification number discrimination prepared in advance. As an example, the following discrimination method is proposed.

If the wave signal P ₊ in the shaded area 8 in FIG. 5 and the wave signal _- in the non-shaded area 9 are represented in the diagram, they will have shapes as shown in FIGS. 6a and 6b, respectively. That is, the signal _- is the signal ₊
The signal is shifted by half a wavelength. Therefore, the signal ₊ obtained by the group of probes in the shaded area 8 in Fig. 5 and the signal _- obtained by the group of probes in the non-shaded area 9 are added together to form c in Fig. 6. When comparing the signal _A shown in Fig. 6d with the subtracted signal _s shown in Fig. 6d, signal _A becomes a signal with a small amplitude because the signals ₊ and P _- cancel each other out, and signal _s becomes a signal with a small amplitude because ₊ and _- are emphasized. becomes a large signal. Let the maximum amplitudes of signals ₊ , _- , _A , and _S be V _P+ , V _P- , V _PA , and V _PS , respectively, and the array probe 4 consists of N probes.
V _PS and V _PA take values as shown in the following equations.

0V _PA 0.2√( ₊ + _- )√( ₊ +
_- ) V _PS N ( ₊ + _- ) ...(9) From the above, a certain identification number (engraved character) 3
, by subtracting the received signal of one probe group of the array probes 4 from the received signals of the remaining probe groups, all the signals received by the individual probes are intensified. It can be seen that a signal with high amplitude can be obtained.

Similarly, when formula (8) is calculated for the case where the engraved character is C shown in FIG. 7, the solution shown in FIG. 8 is obtained in contrast to the solution shown in FIG. 5 for the engraved character A.
The solution in Figure 5 and the solution in Figure 8 are completely different. In other words, it can be seen that the positions where the phase of the signal received by each probe of the array probe 4 becomes positive or negative show completely different patterns if the engraved characters are different.

Therefore, as an example, the stamped characters are A, B, C, D,
For cases E, F, and G, subtract the received signal from the probe group in the shaded area (group) 8 in Figure 5 and the received signal from the probe group in the non-shaded area (group) 9. FIG. 9 shows the signal amplitude when the reflected waves from each engraved character are received in this manner. As is clear from the figure, the signal amplitude for the letter A is three times or more higher than for other letters. From this, the received signal subtracted by a specific combination of probe groups has a large signal amplitude only for a specific engraved character.

Next, a description will be given of what happens to the received signal amplitude when the engraved character of the identification number 3 is shifted from the center position of the array probe 4. Here, we will calculate the amplitude of the received signal when the engraved character A shown in Fig. 4 is shifted by α' in the X-axis direction and β' in the Y-axis direction using the combination of probe groups shown in Fig. 5. It is shown in Figure 10. Figure 10a shows that when β' = 0 and α' is changed,
FIG. 10b shows the amplitude when α'=0 and β' is varied, and the values of α' and β' are shown as values normalized by the width of the probe. It can be seen from the figure that even if the engraved characters are shifted by two probes, the signal amplitude will not be less than 1/2 of the signal amplitude when there is no shift. For this reason, as described above, each ultrasonic probe of the array probe 4 is divided into groups according to the phase difference distribution pattern unique to its engraved character (identification number), and the probe groups between the groups are divided into groups. According to the method of identifying engraved characters from the signal strength (amplitude) obtained by subtracting the received signal, the engraved characters that match the pattern are detected by the array probe 4.
It can be seen that a signal amplitude sufficiently larger than the signal amplitude of other engraved characters can be obtained even if there is some deviation from the character.

For example, the two-dimensional array probe 4 has multiple digits such as A123 in the identification number as shown in Fig. 1, but when using one that faces only one digit as shown in Fig. 2. For each digit, read the number sequentially using the above method, and move the two-dimensional array probe to the next digit each time it is read, or use a two-dimensional array probe for each digit. It is possible to adopt any method in which the probes 4 are arranged horizontally in a line and each two-dimensional array probe is driven for each digit to read the identification number.

The identification method for determining the identification number 2 using the array probe 4 described above is summarized as follows.

1. A two-dimensional array probe is used.

2. Simultaneously transmit ultrasonic waves from the probe group of the two-dimensional array probe. This transmission is performed for each identification number as many times as there are types of characters to be identified.

3. Each time the ultrasonic wave is transmitted, the ultrasonic probe of the two-dimensional array probe is examined in advance, and the grouping is rearranged by a trial of the discriminative phase difference distribution pattern unique to each identification number, and the received signal strength between the groups is determined. Add or subtract. Here, the phase difference distribution pattern unique to each identification number, which serves as the basis for the grouping, is obtained from the calculation result of equation (8) or the actual measured value of the reflected wave phase distribution from each stamped character.

4 Record the maximum amplitude of the above subtracted signal.

5. Detect the order of ultrasonic transmission when the largest of the above maximum amplitudes is obtained.

For example, when trying to discriminate the engraved characters A to G in order, at the fifth transmission (in other words, the ultrasonic waves are received by dividing the probes into groups based on the fifth discrimination phase difference distribution pattern). If the maximum amplitude of the subtraction signal has reached its maximum value, the engraved character will be E.

The advantages of this identification method can be summarized as follows.

(a) Since there is no need to mechanically or electrically scan the probe, the structure of the sensor section and signal processing section becomes simple.

(b) The engraved characters, that is, the identification number 3, can be identified in a short time (approximately 30 milliseconds in the case of alphanumeric characters).

(c) Even if the engraved characters are shifted to the left or right with respect to the probe, they can be reliably identified.

By identifying the above identification number 3, it is possible to automatically determine whether or not the fuel assembly is to be replaced. Therefore, for example, by applying such an identification device to an automatic fuel exchange device that lifts a fuel assembly from a nuclear reactor core and moves it to a predetermined location, it is possible to identify the fuel assembly that is to be replaced. can be replaced quickly and reliably.

FIG. 11 is a schematic diagram showing an embodiment of the automatic fuel exchange system of the present invention installed in a nuclear reactor, to which the above-mentioned identification number discrimination method is applied.

In FIG. 11, 10 is a reactor pressure vessel,
There is a reactor core 11 in the center of the reactor pressure vessel 10,
The reactor core 11 is loaded with fuel assemblies 1 in a grid pattern. 12 is a lifting drive unit, 13 is a fuel assembly grasping machine attached to the tip of the lifting drive unit 12,
Reference numeral 14 denotes a lifting drive control device, which constitutes a fuel assembly lifting mechanism. An array probe 4 is installed in the center of the grasper 13, and a signal processing device 15 controls ultrasonic transmission and reception of the array probe 4 and processes received signals. 16 is a drive control device, 17 is an air pump, 18 is a cylindrical gear rail joined to the inner surface of the upper part of the reactor pressure vessel 10, and 19 is a cylindrical gear rail 1
A straight gear rail 21 runs on a straight gear rail 19 via a gear wheel 20, and a gear wheel 2 runs on a straight gear rail 19.
The gantry 21 travels through the gantry 2, and the gantry 21 is equipped with a lifting drive unit 12, and these constitute a lifting drive unit moving mechanism.

The drive control device 16 drives two air pumps 17 and sends air from the two air pumps 17 to the air motors of the pedestal 21 and the linear gear rail 19, respectively. An air motor rotates about this air, rotating gear wheels 20 and 22 of pedestal 21 and linear gear rail 19, respectively.

FIG. 12 is a perspective view showing an embodiment of the lifting drive unit moving mechanism shown in FIG. 11. In FIG. 12, 30 is an air motor for driving the rotation of the gear wheel 20, and the rotation of the air motor 30 is transmitted to a reverse rotation transmission gear 32 via a transmission shaft 31, thereby causing the other gear wheel 20' to rotate in the reverse direction. Therefore, the linear gear rail 19 rotates on the cylindrical gear rail 18. 33
is an air motor for rotationally driving the gear wheel 22; the rotation of the air motor 33 rotates the gear wheel 22, and the pedestal 21 reciprocates on the linear gear rail 19. Therefore, the drive mechanism shown in FIG. 2 allows the lifting drive unit 12 attached to the pedestal 21 to be moved to any location on the plane surrounded by the cylindrical gear rail 18.

Further, the pulling drive section 12 is expanded and contracted upward and downward by a lifting drive signal and a pulling down drive signal from the pulling drive control device 14 shown in FIG. Furthermore, the grasping machine 13 is opened and closed by the grasping signal.

FIG. 13 is a structural explanatory diagram showing one embodiment of the fuel assembly pulling mechanism shown in FIG. 11. In FIG. 13, the inner periphery 12' of the lifting drive 12 is moved up and down as the puller rotates a gear wheel 35 meshing on a gear 34 on the inner surface of the drive 12. In FIG. The gear wheel 35 rotates when the motor 36 is driven by a drive signal from the drive control device 16 . A gripping device 13 and an array probe 4 are attached to the tip of the inner cylinder 12', and both arms of the gripping device 13 are connected by a spring 37 at the base. These arms open when the head 39 of the piston 38 moves downward, and the piston 38 is opened by the drive control device 16.
It is activated by the grasping signal from. Note that in the event of a failure of the piston 38 or the drive control device 16, the spring 37
Since both arms of the grasping machine 13 close due to the action of , the fuel assembly once grasped will not be dropped.

Next, the signal processing device will be explained. 14th
The figure shows the array probe 4 and signal processing device 1 in Figure 11.
FIG. 5 is a detailed configuration diagram showing an example of No. 5; In FIG. 14, 50 is a transmission/reception control circuit, 51 is a pulser, 52 is a preamplifier, 53 is a switch circuit, 5
4, 54' is an adder, 55 is a subtracter, 56 is a full-wave rectifier, 57 is a peak detector, 58 is a determiner, 5
9 is a peak value memory, 60 is a comparator, 61 is a switch controller, and 62 is a switch pattern memory.

Next, the operation will be described with reference to FIGS. 15 to 18, which show waveforms of signals at each part in FIG. 14. The transmission/reception control circuit 50 is shown in FIGS. 15a and 15b.
The signals A and B shown in the figure are inputted, and the signals E and P shown in the figure c and d are outputted. Signal A is drive control device 1
6 (see FIG. 11), the voltage level becomes "1" when the fuel assembly lifting drive section 12 completes movement to a predetermined position. Signal B is the output signal of the pulling drive control device 14, and is the output signal of the lifting drive control device 14,
When the voltage is lowered to the fuel assembly gripping portion 2 (see FIG. 1), the voltage level becomes "1". That is, when the voltage level of both signals A and B becomes "1", it indicates that the array probe 4 is installed near the grip part 2. The transmission/reception control circuit 50 changes the number from 1 to N (N is the number of types of characters to be identified) when both signals A and B reach the "1" level.
The digital value incremented by 1 at the period T until the signal P
Output as . Furthermore, N pulse signals E are outputted at a period T with a delay of time τ _d from when both the signals A and B reach the “1” level.

In FIG. 16, signals F, G,
H is shown. The pulser 51 outputs a high voltage pulse F shown in FIG. 16b in synchronization with the signal E shown in FIG. 16a, and applies this to the array probe 4 to emit an ultrasound. A reflected wave signal G shown in FIG. 2C obtained by receiving the reflected waves by the array probe 4 is amplified by the preamplifier 52, and becomes an amplified signal H shown in FIG.

In FIG. 17, signals W, I,
J is shown. In the switch circuit 53, the 17th
The signal H shown in FIG.
4' and output them respectively. That is,
The switch controller 61 generates various switch patterns from a switch pattern memory 62 (described later) in synchronization with the rise of the signal E shown in FIG. ) and controls the switch circuit 53 based on this switch pattern to select the probe group to which the received signal should be input to the adder 54 and the probe group to which the received signal should be input to the adder 54'. It has the function of dividing into groups and rearranging the groups each time the switch pattern changes. Specifically, when the voltage level of the signal w is "0", the signal H is outputted to the adder 54, and when it is "1", the signal H is outputted to the adder 54'. Therefore, the signal shown in c in the figure is input to the adder 54, and the signal J shown in d in the figure is input to the adder 54'.

The adders 54 and 54' add the signals I and J input from each switch circuit 53, respectively, and add the signals I and J input from each switch circuit 53.
The signals K and L shown in Figures 8a and 8b are outputted and given to a subtracter 55, which subtracts the signal L from the signal K and gives the signal M shown in Figure 8c to the full-wave rectifier 56. The wave rectifier 56 outputs a full-wave rectified signal N shown in the figure d. peak detector 57
inputs the signal N and outputs the signal 0 shown in the same figure e, which holds the peak value of the full-wave rectified signal when a predetermined time has elapsed after the ultrasonic wave transmission, from the signal N, until τ _d seconds after the ultrasonic wave transmission. do.

The determiner 58 inputs the peak value signal 0, converts this voltage into a digital value, and sequentially records the digital value S in the peak value memory 59. The recording timing is τ seconds after the ultrasonic wave is transmitted (τ τ _d ). After recording N digital values S,
A determiner 58 reads out the digital value S stored in the peak value memory 59 and the signal R at that address, and determines the address where the largest value is recorded among the digital values S, which are N peak values. and,
A digital value T indicating this address is output to the comparator 60. The comparator 60 compares the digital value T and an external setting signal C (address data corresponding to identification number 2 of the fuel assembly to be replaced), and outputs a pulse signal D of voltage level "1" only when the two match. Output. When the pulse signal C is output, the drive control device 16 outputs a grasp signal, the grasper 13 grasps the grip part 2 of the fuel assembly, pulls up the fuel assembly, and starts transferring it to a predetermined position. .

The switch controller 61 reads the value of the signal P when the signal E rises (see FIG. 15), outputs an address signal U corresponding to the value of the signal P to the switch pattern memory 62, and outputs the address signal U from the switch pattern memory 62. A signal X indicating the memory contents of U is input.
Then, the value W of the m-th bit is output to the m-th switch circuit 53 assigned to the m-bit of the signal X. The switch pattern memory 62 stores bit patterns (for example,
If the identification number 2 is engraved with letters A and C, then the 5th
8) are recorded in advance.

According to the above-described embodiment of the present invention, during fuel exchange work, the location of the fuel assembly to be pulled out, the identification number 3 on the top surface of the grip part 2 of the fuel assembly, and the pulled out fuel assembly are relocated. Simply enter the location and the refueling task can be performed automatically. Moreover, the identification number 3 can be reliably identified at high speed and automatically, and reliability can be greatly improved. As a result, the regular inspection period for the reactor can be shortened by two days, and the operating rate can be improved by 1% from the current level.

19 is a perspective view showing another embodiment of the array probe. In FIG. 19, a sound insulating plate 70 is provided on the front surface of the array probe 4.
0 is provided with a sound insulating part shown with diagonal lines in the figure and a cutout part which allows sound to pass through without the diagonal lines. The sound insulating plate 70 is wound around a winding shaft 71 in the form of a film, and the pattern of the sound insulating plate 70 can be sequentially changed by rotating a motor 72. The reflected wave sound insulation distribution pattern of this sound insulating plate is formed to match the reflected wave phase difference distribution pattern unique to each identification number. The squares of the sound insulating plate 70 are the same as or finer than the squares of the array probe 4. This expresses a pattern corresponding to an ultrasonic interference pattern (corresponding to a phase difference distribution), so the finer the pattern, the more accurate the identification. Transmission and reception control of the two-dimensional array probe 4 is performed with this sound insulating plate 70 placed in front.

That is, ultrasonic waves are repeatedly emitted as many times as the number of types of the identification number of the fuel assembly, and each time the ultrasonic waves are emitted, the sound insulating plate 70 with a different sound insulation distribution pattern is sequentially replaced in front of the two-dimensional array probe 4. intervening while controlling the reception of reflected waves from the identification number. In this case, when the sound insulation distribution pattern matches the identification number, the received signal is a reflected wave having a positive or negative phase that is received by the two-dimensional array probe via the sound insulation plate 70. The reception strength is either maximum or minimum. On the other hand, when the sound insulation distribution pattern and the identification number do not match, waves with positive and negative phase differences coexist on the receiving side, so the received signal weakens, and the signal level It can be distinguished from If the structure shown in FIG. 19 is used, the switch circuit 53, adder 54', subtracter 55, switch controller 61, and switch pattern memory 62 of the identification device 15 are unnecessary, and the signal H is directly transmitted to the adder 54. The output signal K of the adder 54 is directly input to the full-wave rectifier 5.
6. however,
Needless to say, a control section for the motor 72 is required. The effect is similar to that of the above embodiment.

Furthermore, although the above-mentioned embodiments have been described using an example of automatic exchange of fuel assemblies loaded in a reactor core, the automatic fuel exchange device according to the present invention is applicable to automatic exchange of fuel assemblies in a fuel reprocessing device. It is also applicable to In addition, as a method of determining an identification number using a reflected wave phase difference distribution pattern as in the present invention, the following may be considered.

For example, the signal strength is measured in a transmitting/receiving group that matches the reflected wave phase difference distribution pattern unique to the identification number. In this case, the concept is similar to when using the sound insulating plate described above, and a specific identification number is determined depending on whether the intensity is above a certain value. Therefore, the transmission/reception is repeated the same number of times as the number of characters to be verified, or the transmission/reception is ended when verification is completed, and the identification number is specified. In addition, transmission is performed all at once, the phase intensity of each receiving probe is recorded, and each phase intensity is added or subtracted to a constant value according to the arrangement of the receiving probes that matches the phase difference distribution pattern of the identification number. It is possible to determine the specific identification number based on whether or not the number is greater than or equal to the above.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to reliably identify the identification number of a fuel assembly in a short time, it is possible to automatically replace a designated fuel assembly in a short time, and the reliability is improved. This has the effect of significantly improving the

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of the arrangement of the grip part and identification number of a fuel assembly, Figure 2 is a diagram showing the positional relationship between the identification number and the array probe, and Figure 3 is a diagram showing the positional relationship between the identification number and the array probe. Figures 4 and 7, which schematically show the geometrical arrangement of the tentacles, have the engraved letters A and C, respectively.
Figures 5 and 8 show the spatial distribution functions in the case of
The figures show the phase difference distribution of ultrasonic waves incident on the array probe when the spatial distribution function has the shapes shown in Figures 4 and 5, respectively. A diagram showing the relationship between the received signals of the child group and their subtracted signals. Figure 9 is a comparison diagram of the amplitude values of the subtracted signals when the engraved characters are A to G. Figure 10 is a diagram showing the relationship between the received signals of the child group and their subtracted signals. Figure 10 is the diagram when the engraved characters are array probes. FIG. 11 is a diagram showing the amplitude change of the subtraction signal when the subtraction signal is shifted parallel to the surface of the nuclear reactor; FIG. 11 is a perspective view showing an embodiment of the pulling drive unit drive mechanism of FIG. 11, and FIG.
11 is a structural explanatory diagram showing an embodiment of the fuel assembly lifting mechanism in FIG. 11, FIG. 14 is a detailed configuration diagram showing an embodiment of the signal processing device in FIG. 11, and FIGS. 15 to 18 are FIG. 14 is a time chart of signals of various parts for explaining the operation, and FIG. 19 is a perspective view showing another embodiment of the array probe. DESCRIPTION OF SYMBOLS 1... Fuel assembly, 2... Gripping part, 3... Identification number, 4... Two-dimensional array probe, 12... Pulling drive unit, 13... Fuel assembly grasping machine, 14...
... Pulling drive control device, 15 ... Signal processing device, 16 ... Drive control device, 18 ... Cylindrical gear rail, 19 ... Straight gear rail, 21 ... Frame,
50... Transmission/reception control circuit, 51... Pulsar, 5
3...Switch circuit, 54, 54'...Adder,
55...Subtractor, 56...Full wave rectifier, 57...
Peak detector, 58... Judgment device, 59... Peak value memory, 60... Comparator, 61... Switch controller, 62... Switch pattern memory, 70...
...Sound insulation board.

Claims (1)

[Scope of Claims] 1. A lifting mechanism that grasps the gripping portion of the fuel assembly and pulls up the fuel assembly, a moving mechanism that moves the lifting mechanism to a specified position, and a driving mechanism for driving the lifting mechanism and the moving mechanism. In the fuel exchange apparatus, a plurality of ultrasonic probes are arranged on a two-dimensional plane at the tip of the pulling mechanism to form a two-dimensional array probe, and the an ultrasonic probe drive means that simultaneously applies a pulse voltage for generating ultrasonic waves to each ultrasonic probe of the two-dimensional array probe; and a transmission/reception control that controls ultrasonic transmission and reception of the two-dimensional array probe. and reflections received by the surface of the two-dimensional array probe when ultrasonic waves are simultaneously transmitted from the two-dimensional array probe toward the identification number engraved on the fuel assembly by ultrasonic transmission/reception control. It is characterized by comprising an identification number discriminating means for determining a wave phase difference distribution pattern and comparing the determined reflected wave phase difference distribution pattern with data related to the phase difference distribution pattern for discrimination to determine an identification number. automatic fuel exchange device. 2. Claim 1 is characterized in that when the determined identification number and the specified identification number match, a fuel assembly grasping signal is output to the lifting mechanism via the drive control device. automatic fuel exchange device. 3 In claim 1 or 2,
The ultrasonic transmission/reception control means causes the identification number of the fuel assembly to repeatedly emit ultrasonic waves for the number of types of the identification number, and each time the ultrasonic wave is emitted, the ultrasonic probe of the two-dimensional array probe is activated. Rearrange the groups and receive the reflected waves from the identification numbers. [When regrouping the groups, check in advance the positive and negative reflected wave phase difference distribution patterns (discrimination phase difference distribution patterns) unique to each identification number. , the ultrasonic probes of the two-dimensional array probe are divided into groups to match the pattern, and the grouping is rearranged each time the phase difference distribution pattern for discrimination is changed], the identification number discrimination. The means adds and subtracts the received signal intensities of the ultrasonic probe groups between the groups each time the groups are rearranged, and creates a phase difference distribution pattern for grouping discrimination that obtains the largest signal intensity among these added and subtracted values. An automatic fuel exchange device consisting of a circuit that calculates an identification number. 4 In claim 1 or 2,
The ultrasonic transmission/reception control means causes the identification numbers of the fuel assemblies to repeatedly emit ultrasonic waves as many times as the types of the identification numbers, and each time the ultrasonic waves are emitted, a reflected wave sound insulation distribution is created in front of the two-dimensional array probe. The configuration is such that the reception and control of reflected waves from the identification number is controlled by sequentially replacing and interposing sound insulating plates with different patterns. [Each sound insulating plate here has a reflected wave phase difference distribution pattern (discrimination A phase difference distribution pattern) is investigated in advance and the identification number is formed based on the pattern. An automatic fuel exchange device that has a circuit configuration that determines an identification number from the number of the sound insulating plate that provides the minimum signal strength.