JPH07306299A - Monitor and ground information transmitter in radioactive waste treating yard - Google Patents

Abstract

PURPOSE:To monitor a deep underground radioactive waste treating yard without laying any signal transmission line. CONSTITUTION:A transmitter/receiver comprising several sensors for individually detecting ground information INF1 is embedded in the ground 2 in the vicinity of a cave 3 confining a waste 39. Heat emitted from the waste 39 is utilized by a thermoelectric conversion element 11 to generate power and an electrostrictive oscillation EV is transmitted in the form of an elastic wave, from an antenna 2 at an oscillation transmitting section based on a sensor signal. A measuring equipment 8 installed on the ground surface 2a catches the electrostrictive oscillation EV to obtain the ground information INF1 in the vicinity of the cave 3 thus monitoring the state of the waste 39. Since no signal transmission line is employed, no water path is formed and interruption of monitoring due to disconnection can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device and a ground information transmitting device in a radioactive waste disposal site suitable for monitoring radioactive waste buried underground.

[0002]

2. Description of the Related Art Conventionally, when radioactive waste is disposed of, a cavity is constructed in a stable stratum located in a deep underground biosphere, the cavity is used as a disposal site, and the waste is placed there. There is a method of closing a disposal site by backfilling a vertical shaft or an inclined shaft excavated for constructing a cavity in which the waste is disposed of, and a residual cavern portion other than the waste in the cavity. When disposing by this method, it is not possible to directly inspect whether the disposed radioactive waste has leaked into the ground around the cavity. Therefore, various sensors capable of detecting various properties of the ground are buried in the vicinity of the cavity together with the waste, and the sensor signal from the sensor is sent to the ground surface through a signal transmission path such as an electric wire or an optical fiber. Then, by using the sensor signal to monitor the ground properties in the vicinity of the closed repository, the stability of the formation near the repository, i.e., the possibility of leakage of radionuclides into the formation, should it be detected. In the form of confirmation, we will continue to confirm the safety of disposal.

[0003]

However, in order to carry out such a monitoring method, a signal transmission line for transmitting a sensor signal as described above is laid in a wire form so as to connect an underground cavity with the surface of the earth. Need to be kept. Then, there is a risk that the signal transmission path itself may become water later, and the pollutants in the disposal site which should have been closed may be carried to the surface of the earth. Also, because of such a monitoring method, devices such as sensors buried in the deep underground cannot be practically maintained or replaced, but in particular, electric wires or optical fibers for signal transmission lines are not provided between the deep underground and the surface of the earth. Since it will be installed over a long distance, it is expected to be difficult to maintain. However, when disposing of such radioactive waste, even a slight leakage of pollutants cannot be tolerated, and it is strongly required to monitor the safety over a long period of time. Elements (i.e. interruptions of monitoring due to formation of water channels or disconnection of signal transmission lines, etc.) should be eliminated as much as possible. Therefore, in view of the above circumstances, the present invention provides a monitoring device and a ground information transmitting device in a radioactive waste disposal site, which enables continuous monitoring of the disposal site over a long period of time without laying a signal transmission path. Is provided.

[0004]

[Means for Solving the Problems] That is, the present invention provides a radioactive waste disposal site (1) for disposing radioactive waste (39) in a closed cavity (3) constructed in the ground (2).
At, in the ground (2) near the cavity (3), a ground information transmitter (7) is provided, and the ground information transmitter (7) detects the state of the radioactive waste (39) and outputs a predetermined signal. (S
n) is output, and a predetermined signal (Sn) from the sensor (10n) is output as an elastic wave (EV).
The elastic wave transmitting means (19, 21) capable of transmitting the electric power (FA) is provided, and the power supply means (11) is provided so that electric power (FA) can be supplied to the ground information transmitter (7). Elastic wave transmission means (1) of the ground information transmitter (7)
The monitoring device (6) is configured by providing an elastic wave detecting means (8) capable of detecting the elastic wave (EV) transmitted by the electromagnetic waves (9, 21). Further, in the present invention, the elastic wave detecting means (8)
Is provided on the ground surface (2a). Alternatively, in the present invention, the elastic wave detecting means (8) is provided in the ground (2). The present invention also provides a radioactive waste (39)
Elastic wave transmitting means that has a sensor (10n) capable of detecting the state of (1) and outputting a predetermined signal (Sn), and can transmit the predetermined signal (Sn) from the sensor (10n) as an elastic wave (EV). (19, 21) are provided, and power supply means (11)
Is provided in a form in which electric power (FA) can be supplied freely, and the ground information transmitting device (70) is configured. Furthermore, the power supply means (11) is configured to generate the electric power (FA) by utilizing the heat released by the radioactive waste (39). The numbers in parentheses () indicate the corresponding elements in the drawings for convenience, and therefore the present description is not limited to the description in the drawings. The same applies to the following action columns.

[0005]

According to the present invention, the ground information transmitter (7) changes the state of the radioactive waste (39) to the elastic wave (E).
When transmitted in the form of V), the elastic wave detecting means (8) acts to detect the elastic wave (EV). Further, in the present invention, the elastic wave detecting means (8) acts so as to detect an elastic wave (EV) on the ground surface (2a). Alternatively, in the present invention, the elastic wave detecting means (8) acts so as to detect an elastic wave (EV) in the ground (2). Further, the ground information transmitting device (70) performs its function by using electric power (FA) as power, and outputs a signal (Sn) from the sensor (10n).
To act as an elastic wave (EV). Further, the power supply means (11) is the power supply means (1
1) It acts so that it can freely supply the electric power (FA) generated by itself.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a state in which an embodiment of a monitoring device according to the present invention is applied to a radioactive waste disposal site, and FIG. 2 is shown in FIG.
3 is a block diagram showing an example of a control system in the monitoring device shown in FIG.

As shown in FIG. 1, a disposal site 1 which is a radioactive waste disposal site is constructed in the ground, that is, in the ground 2, and has a cavity 3 which is already closed. Ground 2 from 2a to a large depth of several hundred meters to several thousand meters
The bottom part of the vertical shaft 2s dug down is formed in an enlarged form so as to have a predetermined capacity. A shielding layer 5 made of a high-quality building material such as bentonite or high-density concrete is formed around the cavity 3 so as to surround the cavity 3, and inside the cavity 3, high-level radioactive waste is generated. The waste 39, which is No. 1, has already been disposed of in a form that has already been processed into a form suitable for underground burial. Then, in the disposal site 1, the residual cave portion other than the waste material 39 in the cavity 3 and the shaft 2s are compacted and filled with the soil 2'for backfilling,
It has already been closed.

At the disposal site 1, as shown in FIG.
A safety monitoring device 6 which is a monitoring device for monitoring the leakage of the waste 39 to the outside of the disposal site 1 is provided, and the safety monitoring device 6 transmits the ground information buried in the ground 2 near the cavity 3. It is composed of a device 70 and a ground measuring device 8 which is an elastic wave detecting means installed on the ground surface 2a. The ground information transmitting device 70, as shown in FIG.
As shown in FIG. 1, the transceiver 7 has a shell body 9 made of a high-strength and durable material, which is composed of a thermoelectric conversion element 11 which is a power supply means capable of supplying electric power FA to the transceiver 7. is doing. The shell body 9 is embedded in the ground 2 in the vicinity of the cavity 3, that is, outside the shielding layer 5 surrounding the cavity 3. The shell 9 has a sensor group consisting of a plurality of sensors 10n capable of detecting various ground properties such as temperature, gas detection, displacement, strain, electric potential, groundwater analysis (pH, Eh, radioactivity, electric conductivity). 10 are connected to each other, and each sensor 10n of the sensor group 10 can detect the state of the waste 39 through these ground properties and output a predetermined sensor signal Sn, respectively. It is embedded in the ground 2 as a sensor owned by.

Further, the thermoelectric conversion element 11 is connected to the shell body 9 as a power supply means capable of supplying the electric power FA to the transceiver 7 as described above.
1 uses the heat emitted by the waste 39 to generate the waste 3
The temperature difference between the high temperature ground 2 whose temperature is raised by 9 and the low temperature ground 2 which is not affected by the temperature rise is such that thermoelectric power generation can be performed in the vicinity of the cavity 3 in a form capable of performing thermoelectric power generation. It is buried in the ground 2. Also, the transceiver 7
As shown in FIG. 2, the control part of is arranged and housed inside the shell body 9, that is, the transceiver 7 has a main control unit 12, and the main control unit 12 has a sensor control unit. The unit 13, the sensor signal conversion unit 15, the reception unit 17, the vibration transmission unit 19, the reception command analysis unit 20, and the like are connected. Sensor control unit 13
The sensors 10n of the sensor group 10 are connected to the sensor signal converter 15 in a wired manner via cables, and the receiver 17 and the vibration transmitter 19 are connected to the electrostrictive vibration EV. Antennas 21 for receiving and transmitting elastic waves such as the monitoring condition designation command MS and the like are respectively connected. Of these, the vibration transmission unit 19 is the sensor 10n.
Of the plurality of sensor signals Sn (that represents the state of the waste 39) from the antenna 21 as electrostrictive vibration EV which is an elastic wave.
The antenna 9 and the antenna 21 are elastic wave transmitting means.

On the other hand, the ground measuring device 8 has a main controller 22 as shown in FIG. 2, and the main controller 22 includes a correction amplifier 23, a data converter 25, and a vibration detector 2.
6, the memory 27, the output unit 29, and the command transmission unit 30 are connected. Of these, the output unit 29 is provided with a recording device 31, and the command transmission unit 30 is provided with, as shown in FIG.
Each input device 32 is detachably connected,
These recording device 31 and input device 32 are installed on the ground surface 2a. Then, the ground measuring device 8 uses the vibration detector 26 to transmit / receive the transmitter / receiver 7 of the transmitter / receiver 70.
Electromotive vibration EV transmitted from the antenna 21 as an elastic wave
The elastic wave detecting means is installed on the ground surface 2a so as to detect On the other hand, the ground measuring device 8 is configured to be capable of transmitting the monitoring condition designation command MS from the command transmitting unit 30 to the antenna 21 of the transceiver 7 of the transceiver 70 as elastic wave vibration. The transmitter / receiver 7 of the transmitter / receiver 70 and the ground measuring device 8 are
It is possible to exchange wireless signals such as V and monitoring condition designation command MS by elastic waves.

Since the disposal site 1 and the safety monitoring device 6 have the above-mentioned configurations, the waste 39 buried in the cavity 3 using the safety monitoring device 6 is disposed in the disposal site 1. However, whether or not there is a leak into the ground 2 outside the cavity 3 or there is a risk of such a leak is continuously monitored for safety by an operation from the ground surface 2a side. By the way, the waste 39, which is a high-level radioactive waste buried in the cavity 3, is stabilized over a long period of time in a form in which radioactive substances in the waste 39 decay while emitting radiation. Follow the way. During this time, the radiation emitted from the waste 39 is prevented from leaking out of the cavity 3 while being shielded by the shielding layer 5. On the other hand, the thermal energy generated by the emission of the radiation raises the temperature of the cavity 3, the shielding layer 5 around it, and the ground 2 around it. Then, the heat transfer conversion element 11 buried in the vicinity of the cavity 3 is provided between the contact portions provided in the ground 2 in the vicinity of the cavity 3 whose temperature has risen and the ground 2 in the portion not affected by the waste 39. Thermoelectric power generation is voluntarily performed according to the temperature difference between.

Therefore, the main control section 12 of the transmitter / receiver 7 supplies to the total receiver 7 the electric power FA generated by the thermoelectric conversion element 11 using the heat emitted by the waste 39 as described above. To supply. Then, the transceiver 7 sends the waste 39
Since the power required for the operation of the transceiver 7 can be supplied from the thermoelectric conversion element 11 as the electric power FA during the period in which the radiation decays while emitting radiation, the landfill 1
The time and effort required to supply power to the transceiver 7 from the ground surface 2a during the period in which the monitoring is required is omitted. Further, it is not necessary to bury a cable for power supply for operating the transceiver 7 in the ground.

In this way, in the transmitter / receiver 70, the closed waste 39 is monitored using the transmitter / receiver 7 by using the electric power FA generated by utilizing the heat emitted from the waste 39 as a power source. To this end, the property of the ground 2 in the vicinity of the cavity 3 in which the waste 39 is disposed and disposed, that is, the ground information is detected, and the state of the waste 39 which is radioactive waste is detected based on the ground information. , We will monitor the safety of disposal site 1.
Therefore, first, the main control unit 12 causes the sensor control unit 13 to cause each sensor 10n of the sensor group 10 to detect the temperature of the ground 2,
Various ground properties such as gas detection, displacement, strain, potential, groundwater analysis (pH, Eh, radioactivity, electric conductivity) are detected, and these are output as sensor signals Sn, respectively. And
The sensor signal Sn from each sensor 10n is input to the sensor signal converter 15 and processed into the shape of the ground information INF1. Then, the main control unit 12 uses the vibration transmission unit 19
In a predetermined output form corresponding to the ground information INF1,
The electrostrictive vibration EV is transmitted from the antenna 21 toward the ground surface 2a side. That is, the vibration transmitting unit 19 uses a sound source formed by an electrostrictive element such as a sub-bottom profiler to generate a continuous wave having a relatively low predetermined frequency with a relatively large exciting force, ie, the ground information INF1 (that is, around the cavity 3). (Representing the property of the ground 2) is output intermittently at intervals corresponding to the electrostrictive vibration EV.

Then, the electrostrictive vibration EV transmitted from the vibration transmitting unit 19 of the transmitter / receiver 7 from the antenna 21 is transmitted as an elastic wave through the ground 2.
Will be transmitted to. Therefore, on the ground surface 2 a, the electrostrictive vibration EV is caught by the ground measuring device 8. At this time, the ground measuring device 8 outputs the output signal sequence sampled at the sampling time point synchronized with the electrostrictive vibration EV that is the driving force signal (that is, the vibration that is received as the response of the electrostrictive vibration EV output by the transceiver 7 as an impulse). The influence of noise is reduced and removed as much as possible by performing a well-known synchronous averaging method in which waveforms are added many times and averaged. Therefore, the main control unit 22 causes the vibration detection unit 26 to detect the response V1 at the location where the ground measurement device 8 is installed, and stores the output signal series of the response V1 in the memory 27. Then, the main control unit 22 includes the correction amplification unit 23.
Then, the response V1 stored in the memory 27 is cumulatively added. Then, since the response V1 has a constant waveform, it increases in proportion to the number of additions,
The noise included in the response V1 becomes large only to the extent of being proportional to the square root of the number of additions by taking a random value of positive and negative for each sampling. Therefore, by adding the response V1 a number of times and averaging the additions, it is possible to sufficiently reduce noise in the signal to be obtained so that it can be ignored. Therefore, the main control unit 22 causes the correction amplification unit 23 to perform such a synchronous averaging method and output the true response V1 corresponding to the electrostrictive vibration EV transmitted by the transceiver 7 earlier. Further, this is processed into a data form by the data conversion unit 25. Then,
The processed data has a form corresponding to the electrostrictive vibration EV transmitted by the vibration transmitting unit 19 of the transceiver 7, and the electrostrictive vibration EV is transmitted corresponding to the ground information INF1 near the cavity 3. Since it has been stored, it becomes data representing the ground information INF1. Therefore, the data is output to the output unit 29.
Output to the recording device 31 and analyzed via the recording device 31, the ground information I based on the properties of the ground 2 near the cavity 3 detected by each sensor 10n of the sensor group 10
NF1 can be detected. Then, according to such ground information INF1, the waste 39 placed in the cavity 3
It is possible to detect and grasp the state of the ground (that is, whether this leaks into the ground 2 or there is a change in the ground 2 that may cause the leak). Therefore, the ground information INF1 is continuously detected and recorded. By doing so, safety monitoring at the disposal site 1 where the waste 39 is disposed can be accurately performed.

Further, according to the safety monitoring device 6, it is possible to selectively measure only the necessary ground properties of the ground 2 in the vicinity of the cavity 3. First, the input device 3
2 through 2, ground properties desired to be measured, that is, sensor group 1
The measurement condition for each sensor 10a of 0 is input. Then, the ground measurement device 8 to which the input device 32 is connected receives this, and the main control unit 22 sends the measurement condition to the command transmission unit 30 in the ground 2 in the form of the monitoring condition designation command MS. Send it to you. The monitoring condition designation command MS does not contain complicated numerical data, but is converted into a simple code, and is converted into an elastic wave in the form of intermittent elastic wave vibration of a predetermined cycle determined in advance. Sent.

Monitoring condition designation command MS transmitted in this manner
Propagates through the ground 2 and reaches the vicinity of the cavity 3.
Then, the antenna 21 of the transceiver 7 catches the monitoring condition designating command MS, and the receiving unit 17 receives it. When the transceiver 7 receives the monitoring condition designation command MS in this manner, the main control unit 12 causes the reception command analysis unit 20 to analyze the monitoring condition designation command MS, and transmits the analysis result to the sensor control unit 13. Receiving this, the sensor control unit 13
Controls the sensor group 10 so as to operate the specific sensor 10n in a specific cycle under the condition corresponding to the monitoring condition designation command MS. As a result, in the sensor group 10, the predetermined sensor 10n selected from the sensor group 10 detects the ground property of the ground 2 in a predetermined cycle. The detection result is output as the sensor signal Sn and is processed and converted into the shape of the ground information INF1 by the same procedure as described above. Then, the ground information INF1 is the ground information INF.
The electrostrictive vibration EV having the output form corresponding to 1 is transmitted from the antenna 21 as elastic wave vibration. Therefore, at the position of the earth's surface 2a, the electrostrictive vibration EV transmitted at this time
If the response V1 of the above is captured and analyzed, the required selective ground information INF1 is detected.

Thus, if the safety monitoring device 6 is used,
The ground information INF1 of the ground 2 near the cavity 3 is detected, and the electrostrictive vibration EV is output in a vibration output form corresponding to the ground information INF1.
Is transmitted from the vicinity of the cavity 3 and the electrostrictive vibration EV is captured by using the ground measuring device 8 to obtain the ground information IN.
F1 can be read at the position on the ground surface 2a. And
Since the ground information INF1 at this time is detected as vibration due to elastic waves in the form of being propagated through the ground 2, the cavity 3
It is not necessary to lay a signal transmission line such as an electric wire or an optical fiber in the form of connecting the position and the ground surface 2a. Further, the transceiver 7 of the transceiver 70 embedded in the ground 2 detects the ground information INF1 by using the electric power FA generated by the heat transfer element 11 from the heat released from the waste 39 as a power as described above. (That is, reading of the sensor signal Sn) and its transmission are performed. Therefore, the transmission / reception device 70 can perform its function while being buried in the ground 2 in a form isolated from the ground surface 2a. Therefore, if the safety monitoring device 6 is used,
There is no need for laying of the signal transmission path or the power supply cable and the maintenance and inspection work therefor, and there is no concern about formation of water channels due to the signal transmission path and the cable. Further, by operating from the ground surface 2a side, it is possible to selectively obtain necessary ground property data by controlling the sensor group 10 in the form of transmitting the monitoring condition designation command MS. Therefore,
Reliable safety monitoring can be performed with the waste 39 completely closed.

In the above embodiment, each sensor 10n detects the ground information INF1 and outputs it as the sensor signal Sn. It may be possible to detect the state of radioactive waste by detecting something other than those mentioned in the examples. Further, in the embodiment, the example in which the vibration transmitting unit 19 can transmit the sensor signal Sn in the form of electrostrictive vibration EV has been described, but the present invention is not limited to the elastic wave transmitting means such as the vibration transmitting unit 19. However, since it is sufficient that elastic waves that can propagate through the ground 2 which is an elastic body can be transmitted, the type of elastic waves, that is, the configuration of the elastic wave transmission source or the like is arbitrary. Further, in the embodiment, the example in which the ground information transmitting device buried in the vicinity of the cavity 3 is the transmitting / receiving device 70 capable of both transmitting and receiving elastic waves has been described, but such a ground information transmitting device is basically In the waste 3
It suffices that the sensor signal Sn representing the state of 9 can be transmitted in the form of an elastic wave such as electrostrictive vibration EV, and whether or not reception and control of the sensor group 10 are possible. Absent. Further, in the embodiment, the electrostrictive vibration EV transmitted by the transceiver 7 embedded in the ground 2 near the cavity 3 is transmitted.
Although an example in which the ground measuring device 8 detects the ground and performs safety monitoring has been described, the ground information transmitting device such as the transmitting and receiving device 70 is not necessarily included in the safety monitoring device 6 as the ground measuring devices 8 and 1.
It is not used in a one-to-one correspondence. That is, since the ground information transmitting device such as the transmitting / receiving device 70 can detect the state of radioactive waste and transmit it as an elastic wave freely, the ground information is transmitted to the vicinity of the cavity where the radioactive waste is closed and disposed. It is also possible to embed only the transmitting device and install the elastic wave detecting means on the ground surface only when necessary to detect the state of the disposed radioactive waste. In addition, in the embodiment, the cavity 3 of the disposal site 1 is
The example of being constructed in the ground 2 which is underground through the shaft 2s dug down from the surface 2a has been described, but the shape of the cavity 3 for burying the waste 39, its construction position, its construction material, etc. All of the above are optional. Therefore, the cavity 3 does not necessarily have to be constructed through the vertical shaft 2s, but may be constructed underground through a slant shaft or the like.

Furthermore, in the safety monitoring device 6 of the above-described embodiment, an example is described in which the ground measuring device 8 for detecting elastic waves such as electrostrictive vibration EV is installed on the ground surface 2a. The elastic wave detecting means such as the above need not be installed on the ground surface 2a, as long as the elastic wave detecting means is arranged at a position sandwiching the ground 2 for a predetermined distance from the cavity 3 in which the waste 39 is closed and disposed. That is, the elastic wave detecting means may be embedded in the ground having a certain depth, that is, in the ground 2. For example, when the cavity 3 is provided at a depth of about 1,000 meters, the elastic wave detecting means may be installed at a depth of about 100 meters. Then, in general, the stratum is formed by covering the hard rock with a soft topsoil (sedimentary layer), and in the transmission of elastic waves, the hard rock has smaller attenuation, so that the ground 2 or solid The elastic wave detecting means provided in the bedrock can more accurately capture the electrostrictive vibration EV which is an elastic wave. In addition, it is not affected by various noises near the ground surface 2a. Therefore, the ground 2
Based on the elastic wave such as the electrostrictive vibration EV detected by the elastic wave detecting means inside, the ground information INF1 can be detected more accurately,
This makes it possible to more accurately grasp the state of the waste 39. Further, since the device board of the elastic wave detecting means provided in the ground 2 is not exposed to the atmosphere, the weather and the like, the deterioration is small, and as a result, the service life of the device board is extended. Further, in the embodiment, since the waste 39 buried in the cavity 3 is a high-level radioactive waste accompanied by heat generation, the heat generation is utilized to utilize the thermoelectric conversion element 11.
Although the example in which the electric power FA can be generated and supplied has been described, the waste 39 may not generate heat enough to generate electric power. In the case of such waste 39 that does not generate heat, as a heat source for thermoelectric power generation, even if the heat source is separate from the waste 39 by utilizing decay heat of radioisotope, like a planetary probe. I do not care. That is,
The power supply means such as the thermoelectric conversion element 11 may have such a radioisotope separately.

[0020]

As described above, according to the present invention, the disposal site 1 or the like for the fixed disposal of radioactive waste such as the waste 39 in the closed cavity 3 constructed in the ground such as the ground 2 or the like. At the radioactive waste disposal site, a ground information transmitter such as a transceiver 7 is provided in the ground near the cavity 3, and the ground information transmitter detects the state of the radioactive waste and outputs a predetermined sensor signal Sn or the like. A thermoelectric conversion element is provided which has a sensor 10n capable of outputting a signal, and is provided with an elastic wave transmission means such as a vibration transmission unit 19 and an antenna 21 capable of transmitting a predetermined signal from the sensor 10n as an elastic wave such as electrostrictive vibration EV. A ground measuring device capable of detecting the elastic waves emitted by the elastic wave transmitting means of the ground information transmitter, by providing a power supply means such as 11 so that the electric power FA can be freely supplied to the ground information transmitter. Eight elastic wave detection means Te, safe since it is configured to monitor the monitoring device 6 or the like, the ground information transmitter transmits in the form of acoustic wave state of radioactive waste, can be detected acoustic wave detection means elastic waves. Then, since the elastic wave propagates through the ground, the state of the radioactive waste detected by the sensor can be detected by the ground information transmitter even if the signal transmission line is not laid to connect the cavity and the surface of the earth. It is transmitted to the detection means. Further, since the power for the ground information transmitter to transmit the elastic wave is covered by the electric power FA supplied by the power supply means, it is not necessary to supply drive power to the ground information transmitter from the ground side. Therefore, no power supply cable is required. Then, there is no concern that a water channel due to such a signal transmission path or a cable for power supply is formed between the cavity where the ground information transmitter is located and the position where the elastic wave detecting means is installed. There is no risk of radioactive waste leakage due to roads. Further, since no signal transmission line or power supply cable is used, there is no risk of interruption of monitoring due to disconnection of these lines. Therefore, it becomes possible to continuously monitor the state of radioactive waste over a long period of time.

In the monitoring device such as the safety monitoring device 6, the power supply means such as the thermoelectric conversion element 11 generates the electric power FA by utilizing the heat released from the radioactive waste such as the waste 39. The power supply means is configured to generate the electric power FA generated by the power supply means itself.
Can be freely supplied to the ground information transmitter such as the transceiver 7. Therefore, as described above, the ground information transmitter detects the state of the radioactive waste and transmits it in the form of an elastic wave. Covered by the heat released. Therefore, when the radioactive waste is accompanied by heat generation, the heat generation can be effectively used. In addition, the power supply means does not need to have a heat source, and power F
It is possible to generate and supply A.

Further, in the monitoring device at the radioactive waste disposal site according to the present invention, the elastic wave detecting means is provided on the surface 2
When it is provided at a, the elastic wave detecting means can detect an elastic wave such as electrostrictive vibration EV on the ground surface 2a. Then, all the operations of the elastic wave detecting means can be performed on the ground surface 2a, so that safety monitoring can be easily performed. Further, it is possible to easily replace each of the parts constituting the elastic wave detecting means. Further, the labor for installing the elastic wave detecting means is simple. As a result, it is possible to easily change the installation location of the elastic wave detecting means, that is, the position for capturing the elastic wave transmitted by the elastic wave transmitting means, so that the elastic wave detecting means is moved to a location where the detection accuracy of the elastic wave is good. Can be done easily. Therefore, it is not necessary to reduce the monitoring accuracy even when the environment near the surface changes after a lapse of years after closing the disposal site.

Alternatively, in the monitoring device at the radioactive waste disposal site according to the present invention, if the elastic wave detecting means is provided in the ground such as in the ground 2, the elastic wave detecting means is elastic in the ground such as electrostrictive vibration EV. Can detect waves. Then, although there is a soft topsoil near the surface 2a, since the ground is a solid rock, it is better to detect the elastic wave in such hard ground because the elastic wave is less attenuated. Also, there are various dark vibrations near the surface 2a,
In the ground, the elastic wave detecting means can accurately detect the elastic wave transmitted by the elastic wave transmitting means without being affected by such dark vibration. Therefore, based on the elastic wave detected by the elastic wave detecting means in the ground, the ground information, that is, the state of the radioactive waste can be detected more accurately.
In addition, since the elastic wave detecting means in the ground is not exposed to the atmosphere, wind and rain, etc., the deterioration of the device board is less, and as a result, the service life of the equipment is extended and accurate safety monitoring is required for a long time. It is possible to continue.

Further, according to the present invention, there is provided a sensor 10n capable of detecting the state of radioactive waste such as the waste 39 and outputting a signal such as a predetermined sensor signal Sn.
An elastic wave transmitting unit such as a vibration transmitting unit 19 and an antenna 21 capable of transmitting a predetermined signal according to the above as an elastic wave such as electrostrictive vibration EV is provided, and a power supply unit such as a thermoelectric conversion element 11 is capable of supplying electric power FA. Since the ground information transmitting device 70 is configured by providing the ground information transmitting device 70, the ground information transmitting device 70 can transmit the signal of the sensor 10n as an elastic wave by performing the function by using the electric power FA as a power source. Therefore, since the ground information transmitting apparatus 70 can transmit the state of the radioactive waste detected by the sensor as an elastic wave by using the electric power FA supplied by the power supply means as power, the ground information transmitting apparatus 70 can generate the radioactive waste. If it is buried in the ground near the closed cavity, the state of the radioactive waste disposed in the cavity can be detected at any time by capturing the elastic wave transmitted by the ground information transmitting device 70 on the ground surface 2a. Can be done. That is,
The radioactive waste disposal site can be monitored. Since the elastic wave transmitted by the ground information transmitter 70 reaches the ground through the ground as described above, the ground information INF1 or the signal transmission path for transmitting the state of radioactive waste from the cavity to the ground. Need not be laid in the ground. Therefore, there is no concern about the risk of becoming unmonitorable due to water channel formation (that is, leakage of pollutants resulting from this) due to the signal transmission path or disconnection of the signal transmission path. That is, it is possible to continuously and safely monitor the disposal site over a long period of time.

Further, the ground information transmitter 7 according to the present invention.
At 0, when the power supply means such as the thermoelectric conversion element 11 is adapted to generate the electric power FA by utilizing the heat released by the radioactive waste such as the waste 39, the power supply means Electric power FA generated by the power supply means itself
The heat source of the electric power FA required for the operation of the ground information transmitting apparatus 70 is covered by the heat emitted by the radioactive waste. Therefore, it is not necessary to provide or supply a heat source to the ground information transmitting device. Therefore, as long as the ground information transmitting device is buried in the ground in the vicinity of the cavity 3, the ground information transmitting device effectively utilizes the heat generation of the radioactive waste to generate its own power and operate. It is possible to continuously detect the ground information INF1 in the ground, that is, the state of the radioactive waste and transmit it as an elastic wave toward the surface of the earth continuously during the period when the radioactive waste is generating heat.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which an embodiment of a monitoring device according to the present invention is applied to a radioactive waste disposal site.

FIG. 2 is a block diagram showing an example of a control system in the monitoring device shown in FIG.

[Explanation of symbols]

 1 …… Radioactive waste disposal site (disposal site) 2 …… Underground (ground) 2a …… Ground surface 3 …… Cavity 6 …… Monitoring device (safety monitoring device) 7 …… Ground information transmitter (transceiver) 70 ...... Ground information transmission device 8 ...... Elastic wave detection means (ground measurement device) 10n ...... Sensor 11 ...... Power supply means (thermoelectric conversion element) 19 ...... Elastic wave transmission means (vibration transmission part) 21 ...... Elastic wave Transmitting means (antenna) 39: radioactive waste (waste) Sn: signal (sensor signal) EV: elastic wave (electrostrictive vibration)

Claims (6)

[Claims] 1. A radioactive waste disposal site in which a radioactive waste is disposed of in a closed cavity constructed underground, wherein a ground information transmitter is provided in the ground near the hollow, and the ground information transmitter is provided. Has a sensor capable of detecting a state of the radioactive waste and outputting a predetermined signal, and is provided with an elastic wave transmitting means capable of transmitting a predetermined signal from the sensor as an elastic wave. Electric power is provided to the information transmitter in a freely supplyable manner, and elastic wave detection means capable of detecting elastic waves emitted by the elastic wave transmission means of the ground information transmitter is provided.
Monitoring equipment at a radioactive waste disposal site. 2. The monitoring device in a radioactive waste disposal site according to claim 1, wherein the power supply means is configured to generate the electric power by utilizing the heat emitted by the radioactive waste. 3. The monitoring device at a radioactive waste disposal site according to claim 1, wherein the elastic wave detecting means is provided on the surface of the earth. 4. The monitoring device at a radioactive waste disposal site according to claim 1, wherein the elastic wave detecting means is provided underground. 5. A sensor for detecting a state of radioactive waste and outputting a predetermined signal, and elastic wave transmitting means for transmitting a predetermined signal from the sensor as an elastic wave are provided, and a power supply means is provided. , A ground information transmitting device configured to be provided with a form in which power can be supplied freely. 6. The ground information transmitting apparatus according to claim 5, wherein the power supply means is configured to generate the electric power by utilizing the heat emitted by the radioactive waste.