JP2013072764A - Cask monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and freely construct a cask monitoring function when keeping or storing a plurality of casks, and to also improve workability.SOLUTION: A cask monitoring device of the present invention is the device for monitoring a state of a cask 1 used when keeping or storing used fuel or radioactive materials, and includes a shield body 2 provided around each cask 1 for shielding radiation from the cask 1, and a monitoring board 3 installed on an outer wall of the shield body 2 for indicating the state of the cask 1 so as to be monitored.

Description

  The present invention relates to a cask which is a container having a safety function such as a sealing function and a heat removal function used for transporting, storing or storing spent nuclear fuel or radioactive material, and more particularly to a monitoring device for monitoring the state of the cask.

  When storing or storing a cask in a building such as a nuclear facility, a pressure sensor for monitoring the pressure between the double lids of the cask and the cask are used to confirm that the safety function of the cask is maintained. The cask is equipped with a temperature sensor that monitors the surface temperature of the cask.

  A plurality of casks were stored or stored in the building, and the output signals of the pressure sensor and temperature sensor of each cask were sent to a centralized monitoring panel, and the safety state of each cask was monitored at one place.

  In addition, in order to store the cask more safely, there is a technique in which a movable shielding wall is provided around the cask installed on the floor, thereby blocking the lateral and upward radiation radiated from the cask. 1 was proposed.

Japanese Unexamined Patent Publication No. 09-1113677 (see FIG. 2)

  As described above, when the cask is stored or stored, the pressure sensor is used to monitor the sealing state of the cask, and the temperature sensor is also used to monitor whether heat removal from the spent fuel or radioactive material is properly performed. . In some cases, the cask is surrounded by a shielding wall to take safety measures against radiation.

  However, the method of monitoring each cask state with the centralized monitoring panel can plan the capacity of the centralized monitoring panel according to the quantity of the cask to store or store in advance, but the quantity is not determined In this case, the capacity of the centralized monitoring panel is insufficient or surplus. Further, every time an additional cask is stored or stored, a new cable needs to be prepared and connected from the sensor of the additional cask to the central monitoring panel.

  In addition, when there are restrictions on the area and shape of the site, the number of casks to be centrally stored or stored is limited, and it is necessary to store or store them in a distributed manner.

  In addition, it is better to place multiple casks as much as possible with an emphasis on safety, but the cask distribution is limited because the signal cables of each cask are routed to a centralized monitoring panel. There is also a problem.

  In addition, since the cask and the central monitoring panel are separated from each other, even if an operator is in the immediate vicinity of the cask, the pressure and temperature state of the cask cannot be confirmed, and workability is low.

  In view of the above-described problems, an object of the present invention is to easily and freely construct a monitoring function of individual casks when storing or storing a plurality of casks, and to improve workability.

  One aspect of the present invention relates to a cask monitoring device that monitors the state of a cask used when storing or storing spent fuel or radioactive material. Further, the cask monitoring device includes a shielding body provided around each cask for shielding radiation from the cask, and monitoring means installed on the outer wall of the shielding body and capable of monitoring the state of the cask. Including that.

  According to the present invention, when a plurality of casks are stored or stored, a monitoring function for individual casks can be easily and freely constructed, and workability is improved.

1 is an external perspective view showing a cask monitoring device according to an embodiment of the present invention. The front view of the monitoring board of FIG. The control block diagram which shows the control structure containing the signal cable etc. which connect the cask shown in FIG. 1 and a monitoring board. FIG. 4 is a control block diagram showing a modification example instead of the control configuration of FIG. 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view showing a cask monitoring apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the cask monitoring apparatus of the present embodiment includes a shielding body 2 that confines the cask 1 and a monitoring panel 3 that is installed on the outer wall of the shielding body 2.

  The shielding body 2 includes a concave container 2a and a lid 2b that seals the opening of the recess, and the radiation radiated from the cask 1 by inserting the cask 1 into the concave container 2a and closing the recess opening of the concave container 2a with the lid 2b. It is possible to shield. In addition, the structure of the shielding body applicable to this invention is not restricted to the thing of illustration. Further, the posture of the cask is not limited to the illustrated horizontal orientation.

  FIG. 2 is a front view of the monitoring panel 3.

  As shown in FIG. 2, the monitoring panel 3 includes a pressure indicator 3a (two in this example) that displays the pressure between the double lids of the cask 1, and a temperature indicator 3b that displays the surface temperature of the cask 1. And an abnormality notification lamp 3c for notifying the abnormality of the cask 1 based on the values of the pressure and the temperature.

  FIG. 3 is a control block diagram showing a control configuration including a signal cable connecting the cask 1 and the monitoring panel 3. In FIG. 3, the shielding body 2 is omitted.

  As shown in FIG. 3, the cask 1 is provided with a pressure sensor (PE) 4 that measures the pressure inside the lid, and a temperature sensor (TE) 5 that measures the surface temperature. In this example, two pressure sensors 4 are arranged and one temperature sensor 5 is arranged, but the number of each sensor is not limited to this, but the function of one sensor breaks down by using a plurality of sensors. There is an advantage that the cask monitoring is not disabled.

  A signal cable 6 is individually laid from each pressure sensor 4 and temperature sensor 5 to the monitoring panel 3. The monitoring panel 3 is provided with a pressure indicator (PI) 3 a connected to each pressure sensor 4 by a signal cable 6 and a temperature indicator (TI) 3 b connected to the temperature sensor 5 by a signal cable 6. Yes. The monitoring panel 3 further includes a pressure amplifier (PT) 7 for amplifying the pressure sensor signal between the pressure indicator 3 a and the pressure sensor 4, and signal values of the pressure sensor 4 and / or the temperature sensor 5 in the cask 1. An abnormality notification lamp 3c that is turned on when the pressure corresponds to the abnormal pressure is provided. These cask monitoring electrical components can be operated by electricity supplied from the power supply 8 to the monitoring panel 3. Although not shown, the monitoring panel 3 includes a comparison operation circuit that determines whether or not the signal value of the pressure sensor 4 and / or the temperature sensor 5 is a pressure value indicating an abnormality in the cask 1.

  According to the embodiment described above, the following effects can be obtained. That is, the shielding body 2 is provided for each cask 1 and the monitoring panel 3 is individually installed on the outer wall of the cask 1, so that the cask 1 in the shielding body 2 can be used when building a function for monitoring the state of the cask. Since it is only necessary to connect the monitoring panels 3 on the outer wall of the cask with a short cable, the burden on the construction of the monitoring function is small. For example, in the case of this embodiment, there is no shortage or excess of the capacity of the centralized monitoring panel as in the prior art, and every time a cask to be stored or stored is added, the long cable to the centralized monitoring panel No laying is required. In addition, since there is no such cable laying, the dispersed arrangement of the cask is not restricted, and safety is improved.

  Since the monitoring panel 3 is installed on the outer wall of the shielding body 2, the worker can monitor the sealing pressure and surface temperature of the cask 1 in the immediate vicinity of each cask 1, and further, the abnormality notification lamp 3c. Thus, the abnormality of the cask 1 can be known.

  In the embodiment described above, the abnormality notification lamp 3c is prepared as a means for notifying the abnormality of the cask 1. However, the present invention is not limited to this, and the abnormality is notified by making a sound or by sending a radio wave. A component to be notified may be added. By adding the notification means by sound or radio wave, it is possible to notify the abnormality of the cask even if there is an operator away from the cask 1.

  Further, in the above-described cask monitoring apparatus, as shown in FIG. 3, the cask 1 is provided with a thermoelectric conversion element 9 that converts heat generated in the cask 1 into electricity, and the output of the thermoelectric conversion element 9 is a power supply line to the monitoring panel 3. 10 may be provided. When the cask 1 is made of a steel container having a thickness of about 300 mm, for example, heat of about 200 ° C. is generated inside the cask and several tens of degrees C. on the cask surface. The thermoelectric conversion element 9 performs thermoelectric conversion using the temperature difference between the inner and outer surfaces of the cask, and is installed on the container body or the lid of the cask 1.

  According to the additional configuration of the thermoelectric conversion element 9, even if the power supply to the electrical components of the monitoring panel 3 stops, the state of the cask 1 can be continuously monitored by the electricity of the thermoelectric conversion element 9. Further, depending on the amount of power generated by the thermoelectric conversion element 9, it is possible to eliminate the power source 8 for operating the sensors 4, 5 and the indicator meters 3a, 3b, etc. prepared for monitoring the state of the cask 1. This eliminates the need for a plurality of power cables connecting the power supply 8 to the monitoring panel 3 installed in each cask 1, thereby improving the workability of cask storage or storage.

  Also, electricity can be supplied to the electrical components of the monitoring panel 3 using solar power generation equipment and a storage battery instead of the thermoelectric conversion element 9. That is, as shown in FIG. 4, a photovoltaic power generation panel 11 that converts the light energy of sunlight into electricity using the photovoltaic effect is provided on the shielding body 2, and the output of the photovoltaic power generation panel 11 is You may provide the structure connected to the power supply line 10 to the monitoring board 3. FIG. It is preferable that the solar power generation panel 11 is installed in the upper part of the lid | cover 2b shown in FIG.

  If the solar power generation panel 11 cannot generate enough power, the solar power generation panel 11 is provided with a storage battery 12 and the surplus electricity generated in the daytime is stored in the storage battery 12 so that the electricity of the storage battery 12 The state of the cask 1 can be continuously monitored.

DESCRIPTION OF SYMBOLS 1 Cask 2 Shield 2a Concave container 2b Cover 3 Monitor panel 3a Pressure indicator 3b Temperature indicator 3c Abnormal alarm lamp 4 Pressure sensor 5 Temperature sensor 6 Signal cable 7 Pressure sensor 8 Power source 9 Thermoelectric conversion element 10 Power supply line 11 Sunlight Power generation panel 12 Storage battery

Claims (5)

A cask monitoring device for monitoring a state of a cask used when storing or storing spent fuel or radioactive waste,
A shielding body provided around each cask to shield radiation from the cask;
A cask monitoring device, comprising: monitoring means installed on an outer wall of the shielding body and capable of monitoring the state of the cask. The cask includes a pressure sensor that measures the pressure inside the cask, and a temperature sensor that measures the surface temperature of the cask,
The monitoring means is a pressure indicator that is electrically connected to the pressure sensor and displays a pressure measured by the pressure sensor, a temperature indicator that is electrically connected to the temperature sensor and displays a surface temperature measured by the temperature sensor, and The cask monitoring apparatus according to claim 1, further comprising a notifying unit that notifies an abnormality of the cask based on a measurement result of the pressure sensor and / or the temperature sensor.   The cask monitoring apparatus according to claim 2, wherein the notifying unit notifies the abnormality of the cask using at least one of lighting, sound, and radio waves.   The cask monitoring apparatus according to any one of claims 1 to 3, wherein the cask is provided with a thermoelectric conversion element, and the thermoelectric conversion element is used as a power source for operating the monitoring means.   The photovoltaic system and the storage battery are provided in the shielding body, and the photovoltaic system and the storage battery are used as a power source for operating the monitoring means. Cask monitoring equipment.

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