A radioactive solid waste storage system, method and ventilation equipment

Abstract

This invention discloses a ventilation device for a radioactive solid waste storage system. The ventilation device includes a normal exhaust mechanism and an abnormal exhaust mechanism. The normal exhaust mechanism ventilates the storage unit when it is not radioactive, while the abnormal exhaust mechanism ventilates the storage unit when it is radioactive, simultaneously filtering radioactive aerosols from the ventilation airflow. A control unit is electrically connected to the ventilation device and controls the switching between the normal and abnormal exhaust mechanisms based on the radioactive aerosol level in the storage unit, and controls the airflow of the ventilation device based on the temperature of the storage unit. The ventilation device of this invention can detect various problems that may occur during waste container storage, thereby automatically adjusting the ventilation and improving storage safety. This invention also provides a radioactive solid waste storage system and storage method.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste treatment technology, specifically to a radioactive solid waste storage system, method, and ventilation equipment. Background Technology

[0002] Currently, the technology for disposing of intermediate and high-level radioactive waste is not yet mature, and the common practice for handling such waste is through monitored storage. According to Announcement No. 65 of 2017, "Classification of Radioactive Waste," jointly issued by the Ministry of Environmental Protection, the Ministry of Industry and Information Technology, and the State Administration of Science, Technology and Industry for National Defense on December 1, 2017, the waste stored in intermediate and high-level radioactive solid waste temporary storage facilities is divided into two types: one is waste containing alpha emitter nuclides with an activity concentration greater than or equal to 4 × 10⁻⁶. 6 Intermediate-level radioactive solid waste is categorized into two types: intermediate-level and high-level radioactive solid waste. Generally, intermediate- and high-level radioactive solid waste is sealed in waste containers with an α-sealing function and then hoisted to a temporary storage facility using a hoisting device. Intermediate- and high-level radioactive solid waste, especially high-level waste, generates a large amount of heat and may release aerosols during storage; therefore, a reasonable design is needed to ensure the safety of its storage.

[0003] Currently, most designs for temporary storage facilities for intermediate and high-level radioactive waste involve storing radioactive waste containers in storage wells within concrete storage units. These wells are typically equipped with shielding covers, and ventilation usually involves creating openings in the concrete walls of the storage units to allow airflow between units, thus removing the decay heat from the intermediate and high-level radioactive waste. However, these conventional designs rely on very limited monitoring methods for the storage units, making it difficult to handle various emergencies and often leading to misjudgments and unnecessary waste of manpower. Summary of the Invention

[0004] The technical problem to be solved by this invention is to address the aforementioned shortcomings in the prior art by providing a ventilation device for a radioactive solid waste storage system. This device can detect various problems that may occur during waste container storage, thereby automatically adjusting the ventilation and improving storage safety. This invention also provides a radioactive solid waste storage system and storage method.

[0005] This invention provides a ventilation device for a radioactive solid waste storage system, installed in each storage unit of the system, including a control unit and a ventilation device. The ventilation device includes a normal exhaust mechanism and an abnormal exhaust mechanism. The normal exhaust mechanism is used to ventilate the storage unit when it is not radioactive, and the abnormal exhaust mechanism is used to ventilate the storage unit when it is radioactive, while filtering radioactive aerosols in the ventilation airflow. The control unit is electrically connected to the ventilation device and is used to control the switching between the normal exhaust mechanism and the abnormal exhaust mechanism according to the level of radioactive aerosols in the storage unit, and to control the airflow of the ventilation device according to the temperature of the storage unit.

[0006] Preferably, the control unit includes a radioactivity detection device and a controller. The radioactivity detection device is electrically connected to the controller and is used to detect the level of radioactive aerosols in the storage unit and send it to the controller. The controller is used to determine whether a preset condition has been met based on the received level of radioactive aerosols. When the determination result is that the level of radioactive aerosols has met the preset condition, the controller controls the abnormal ventilation mechanism to open and controls the normal ventilation mechanism to close. When the determination result is that the received level of radioactive aerosols has not met the preset condition, the abnormal ventilation mechanism is kept closed and the normal ventilation mechanism is opened.

[0007] Preferably, the radioactive detection device includes a first detection mechanism and a second detection mechanism. The first detection mechanism is located at the exhaust duct of the storage unit. Multiple second detection mechanisms are used, and each of the multiple second detection mechanisms is located at a storage well in the storage unit. The controller is electrically connected to the first and second detection mechanisms respectively, and is used to determine whether a preset condition has been reached based on the radioactive aerosol level detected by the first detection mechanism. When the radioactive aerosol level reaches the preset condition, the controller controls the second detection mechanism to open. The controller is also used to determine the storage well where the radioactive leak is located based on the radioactive aerosol level detected by each second detection mechanism and generate alarm information.

[0008] Preferably, the preset conditions include an α radioactivity concentration exceeding 0.06 Bq / m³ and / or a β radioactivity concentration exceeding 15 Bq / m³. 3 .

[0009] Preferably, the control unit further includes a temperature detection device electrically connected to the controller, which is used to detect the temperature value of the storage unit and send it to the controller. The controller is used to compare the received temperature value with the preset temperature value stored in it, and control the air volume of the ventilation device accordingly when the temperature value exceeds the preset temperature value.

[0010] The control unit also includes a model analysis device, which is electrically connected to the controller and contains a model corresponding to the storage unit. The controller sends the received temperature value to the model analysis device when the temperature value exceeds the preset temperature value. The model analysis device analyzes the temperature value and the preset cooling time to obtain the air volume value corresponding to the storage unit reaching below the preset temperature value within the preset cooling time, and sends it to the controller. The controller controls the air volume of the ventilation device according to the air volume value.

[0011] Preferably, the control unit further includes a running detection device, and the controller is also electrically connected to the running detection device for controlling the running detection device to start when the received temperature value exceeds a preset temperature value. The running detection device is used to detect the operating status of the ventilation device and send the detection result to the controller. When the detection result indicates that the operating status of the ventilation device is normal, the controller controls the air volume of the ventilation device. When the detection result indicates that the operating status of the ventilation device is abnormal or stopped, the controller generates alarm information.

[0012] Preferably, the ventilation device further includes an air supply mechanism, which is connected to the air inlet duct of the storage unit and is used to provide airflow for ventilation of the storage unit. The control unit is electrically connected to the air supply mechanism and is used to control the air volume of the air supply mechanism according to the temperature of the storage unit, so as to control the air volume of the ventilation device.

[0013] The present invention also provides a radioactive solid waste storage system, comprising at least one storage unit, wherein the storage unit includes a storage room, a storage well, and ventilation equipment of the radioactive solid waste storage system described above. Multiple storage wells are provided, arranged in the storage room for storing waste containers. Air inlet ducts and exhaust ducts are provided on the walls of the storage room. In the ventilation equipment of the radioactive solid waste storage system, normal exhaust mechanisms and abnormal exhaust mechanisms can be switched and connected to the exhaust ducts.

[0014] Preferably, the storage unit further includes a hoisting device, which is located above the storage chamber and is used to hoist the waste bins into or out of the storage well.

[0015] Preferably, at least one of the multiple storage wells is a sealed structure, and the rest are unsealed structures. The waste bin is stored in the unsealed storage well. The control unit is also electrically connected to the hoisting device and is used to determine the storage well where the radioactive leak is located based on the level of radioactive aerosol, and to control the hoisting device to hoist the waste bin in the storage well where the radioactive leak is located to the sealed storage well.

[0016] Preferably, the connection between the air inlet duct and the storage chamber and the connection between the air outlet duct and the storage chamber are located at the upper and lower ends of the storage chamber, respectively.

[0017] The present invention also provides a method for storing radioactive solid waste, using the above-mentioned radioactive solid waste storage system, the method specifically including the following steps:

[0018] Turn on the ventilation equipment of the radioactive solid waste storage system;

[0019] The hoisting device is controlled to lift the waste bins into a non-sealed storage well.

[0020] Sealed storage well;

[0021] The detection and processing of radioactive aerosol levels in the storage unit includes:

[0022] a. When it is determined that the level of radioactive aerosol in the storage unit has not reached the preset conditions, the abnormal ventilation mechanism is kept closed, and the normal ventilation mechanism is opened.

[0023] b. When the level of radioactive aerosol in the storage unit is determined to reach the preset condition, the abnormal ventilation mechanism is activated and the normal ventilation mechanism is closed. The hoisting device is then used to hoist the waste container in the storage well where the radioactive leak occurred to the sealed storage well.

[0024] The ventilation equipment of the radioactive solid waste storage system of the present invention is installed in each storage unit of the storage system, including a control unit and a ventilation device. The control unit can control the ventilation device to adjust the ventilation volume and ventilation mode of the storage unit according to the detection situation in the storage unit. Therefore, compared with the traditional single ventilation equipment, this equipment not only performs simple ventilation and monitoring functions, but can also make corresponding adjustments according to the situation of the storage unit. Therefore, it has a certain automatic handling and adjustment capability after the storage unit malfunctions, avoiding unnecessary waste of manpower.

[0025] Specifically, the control unit can switch between normal and abnormal ventilation mechanisms based on the level of radioactive aerosols, thereby achieving different ventilation modes. It can also adjust the ventilation volume based on temperature, which means it can respond promptly to various emergencies that may occur during waste bin storage, such as radioactive aerosol leakage and temperature rise, thereby improving storage safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the connection of the ventilation equipment in the radioactive solid waste storage system of Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the storage unit of the radioactive solid waste storage system in Embodiment 2 of the present invention.

[0028] In the diagram: 1. Storage room; 11. Air inlet duct; 12. Air outlet duct; 2. Storage well; 21. Shielding cover; 22. Well shaft; 3. Lifting device. Detailed Implementation

[0029] The technical solutions of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without creative effort are within the scope of the invention.

[0030] In the description of this invention, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience and simplification of the description and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] In the description of this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," "installation," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] Example 1

[0034] like Figure 1 and Figure 2 As shown, the ventilation equipment of the radioactive solid waste storage system in this embodiment is installed in each storage unit of the storage system, including a control unit and a ventilation device. The ventilation device includes a normal exhaust mechanism and an abnormal exhaust mechanism. The normal exhaust mechanism is used to ventilate the storage unit when it is not radioactive, and the abnormal exhaust mechanism is used to ventilate the storage unit when it is radioactive, while filtering radioactive aerosols in the ventilation airflow. The control unit is electrically connected to the ventilation device and is used to control the switching between the normal exhaust mechanism and the abnormal exhaust mechanism according to the level of radioactive aerosols in the storage unit, and to control the airflow of the ventilation device according to the temperature of the storage unit.

[0035] In this embodiment, the control unit can control the ventilation device to adjust the ventilation volume and ventilation mode of the storage unit according to the detection situation in the storage unit. Therefore, compared with traditional single ventilation equipment, this equipment not only performs simple ventilation and monitoring functions, but can also make corresponding adjustments according to the situation of the storage unit. Therefore, it has a certain automatic processing and adjustment capability after the storage unit malfunctions, avoiding unnecessary waste of manpower.

[0036] Specifically, the control unit can switch between normal and abnormal ventilation mechanisms based on the level of radioactive aerosols, thereby achieving different ventilation modes. It can also adjust the ventilation volume based on temperature, which means it can respond promptly to various emergencies that may occur during waste bin storage, such as radioactive aerosol leakage and temperature rise, thereby improving storage safety.

[0037] In this embodiment, the control unit includes a radioactivity detection device and a controller. The radioactivity detection device is electrically connected to the controller and is used to detect the radioactive aerosol level in the storage unit and send it to the controller. The controller is used to determine whether a preset condition has been met based on the received radioactive aerosol level. If the determination result is that the radioactive aerosol level has met the preset condition, the controller controls the abnormal ventilation mechanism to open and the normal ventilation mechanism to close. If the determination result is that the received radioactive aerosol level has not met the preset condition, the abnormal ventilation mechanism remains closed and the normal ventilation mechanism is opened. The radioactivity detection device is used to detect the radioactive aerosol content in the storage unit, namely the α-radioactivity concentration and β-radioactivity concentration. It determines whether there is an aerosol exceeding the standard by sampling and measuring the radioactive aerosol concentration in the storage unit.

[0038] In this embodiment, the ventilation device further includes an air supply mechanism connected to the air inlet duct 11 of the storage unit. The air supply mechanism includes an air intake tower and an air conditioning unit. Outdoor fresh air is filtered by the air intake tower and then delivered to the storage unit through the air inlet duct 11 to provide airflow for the storage unit. The air supply mechanism is always kept open. A control unit is electrically connected to the air supply mechanism and controls the airflow of the air supply mechanism according to the temperature of the storage unit, thereby controlling the airflow of the ventilation device.

[0039] The storage unit's exhaust duct 12 has two branch structures at its end. Normal and abnormal exhaust mechanisms are respectively located in these two branch structures. Exhaust airflow is drawn from the storage unit's exhaust duct 12 and enters the branch structures. Both the normal and abnormal exhaust mechanisms are equipped with centrifugal exhaust fans for drawing airflow and valves. The control unit switches between these mechanisms by opening and closing the valves. Normal exhaust air is directly discharged to a point 3m above the factory roof for atmospheric diffusion via the centrifugal exhaust fan. Abnormal exhaust air undergoes one or more stages of filtration before being discharged to the chimney via the centrifugal exhaust fan and exhaust duct. The chimney height must comply with Section 5.5.4 of EJ / T938-95, which stipulates that when air potentially containing radioactive materials is discharged from the top of a building, the chimney outlet height should be 3m higher than the tallest building within 50m of the nearest building. The normal exhaust mechanism and the abnormal exhaust mechanism can switch between the exhaust duct 12 connected to the storage unit. The abnormal exhaust mechanism filters the airflow containing radioactive aerosols in the storage unit under accident conditions. The normal exhaust mechanism can also be equipped with a primary filter, which can be a housing filter. The control unit controls the normal and abnormal exhaust mechanisms by controlling the valves to open and close the exhaust duct 12 and the corresponding ventilation mechanism, thus completing the switching.

[0040] Under normal circumstances, the exhaust air in storage room 1 is discharged through exhaust duct 12 and then through the normal exhaust mechanism. The number of air changes of the normal exhaust mechanism is calculated based on the decay heat generated by the intermediate and high radioactive solid waste in the waste storage unit (the calculation process is described below). The abnormal exhaust mechanism adds one or more stages of filtration to the normal exhaust mechanism. Under abnormal operating conditions, the system switches from the normal exhaust mechanism to the abnormal exhaust mechanism to filter the exhaust air in storage room 1 before discharge. In addition to removing the decay heat generated by the intermediate and high radioactive solid waste, it also reduces the concentration of radioactive aerosols in the waste storage unit.

[0041] In this embodiment, the radioactive detection device includes a first detection mechanism and a second detection mechanism. The first detection mechanism is located at the exhaust duct 12 (or exhaust pipe) of the storage unit and is used to detect the overall radioactive aerosol level of the storage unit. Multiple second detection mechanisms are used, each located at a storage well 2 within the storage unit and connected to the shielding cover 21 of the storage well 2. A sampling tube is embedded within the shielding cover 21 of the storage well 2, and a quick connector is provided at the end of the sampling tube. The sampling tube on the shielding cover 21 can be quickly connected to a portable aerosol sampler or a mobile aerosol activity meter to sample and measure the gas inside the well, thereby detecting the radioactive aerosol level in each storage well 2. In other words, the second detection mechanism also uses the method of sampling and measuring the radioactive aerosol concentration in the storage well 2 to determine whether there is an excessive aerosol level in the storage well 2.

[0042] The controller is electrically connected to the first and second detection mechanisms respectively. It is used to determine whether the preset conditions have been met based on the level of radioactive aerosol detected by the first detection mechanism. When the level of radioactive aerosol reaches the preset conditions, the controller controls the second detection mechanism to open. The controller is also used to determine the location of the radioactive leak in the storage well 2 based on the level of radioactive aerosol detected by each of the second detection mechanisms and generate alarm information.

[0043] When the preset conditions are met, it indicates that there is a leak in the storage unit. Therefore, activating the second detection mechanism can further compare the radioactive aerosol levels of each storage well 2 with the preset conditions to determine which one or more storage wells 2 have reached the preset conditions and leaked. This provides accurate location or number information in the alarm information for subsequent processing, further accelerating the processing efficiency and avoiding wasting processing time by checking each one individually.

[0044] In this embodiment, the aforementioned preset conditions include an alpha radioactivity concentration exceeding 0.06 Bq / m³. 3 and / or β radioactivity concentration exceeding 15 Bq / m 3 That is, if either of the two conditions is met, the storage unit is considered to have a leak.

[0045] In this embodiment, the control unit includes a temperature detection device and a controller. The temperature detection device is electrically connected to the controller and is used to detect the temperature value of the storage unit and send it to the controller. The controller is used to compare the received temperature value with the preset temperature value stored in its internal memory, and to control the airflow of the ventilation device when the temperature value exceeds the preset temperature value. In this embodiment, the controller electrically connected to the temperature detection device and the controller electrically connected to the aforementioned radioactivity detection device can be the same controller. Since, according to the specifications, the long-term heat resistance temperature of concrete is 65℃, and the short-term heat resistance temperature of concrete under accident conditions is 180℃, in this embodiment, for safety considerations, the preset temperature value is selected to be no higher than 65℃. Specifically, the temperature detection device detects the temperature value of the concrete wall of storage chamber 1 in the storage unit to avoid the concrete from overheating and affecting its service life. It is preferred to embed a temperature measuring instrument in the concrete close to the inner wall of the exhaust duct 12 of storage chamber 1 to monitor the temperature of the concrete in real time. After an abnormal overheating condition occurs, the temperature is reduced to a normal level by increasing the ventilation airflow.

[0046] Temperature measuring instruments are placed on the exhaust side because the air is continuously heated throughout its path from supply to exhaust in the storage unit. The hot air reaching the exhaust side has a higher temperature, which, through heat transfer, causes the concrete temperature on that side to be higher than on the other sides. This is also shown in the concrete temperature distribution map calculated using ANSYS CFX software. Therefore, detecting the concrete temperature on the exhaust side is representative; if the temperature on this side does not exceed the standard, it can be determined that the entire storage unit will not exceed the standard.

[0047] Increasing ventilation volume specifically refers to increasing the air exchange rate. The air exchange rate is calculated based on the decay heat generated by the high-level radioactive solid waste within the storage unit. The air exchange rate refers to the number of times the total amount of air in a space is completely removed and replaced within one hour. Air exchange rate = air supply volume / space volume. For example, a storage unit with a volume of 600 m³... 3 The air supply volume is 3000m³. 3 If the air exchange rate is 5 times per hour, then the air exchange rate is 5 times per hour (this is just an example).

[0048] In this embodiment, the control unit also includes a model analysis device, which is electrically connected to the controller. The model analysis device contains a model corresponding to the storage unit. The controller sends the received temperature value to the model analysis device when the temperature value exceeds the preset temperature value. The model analysis device analyzes the temperature value and the preset cooling time to obtain the air volume value corresponding to the storage unit reaching below the preset temperature value within the preset cooling time, and sends it to the controller. The controller controls the air volume of the ventilation device according to the air volume value.

[0049] The model analysis device has a pre-set model corresponding to the storage unit. By setting input conditions (such as the air supply volume, air inlet temperature, and decay heat of the waste bin), and assuming the heat transfer mode and heat transfer coefficient of each part of the storage unit according to the actual environmental conditions (such as not considering convective heat transfer between the concrete at the bottom and sides of the storage unit and the environment; considering convective heat transfer between the top of the storage unit and the environment, and selecting empirical values ​​for the heat transfer coefficient; treating the air between the waste bin and the storage well shaft as solid; considering radiative heat transfer between the outer wall of the storage well shaft and the inner wall of the concrete of the storage unit, etc.), the concrete temperature of each area can be calculated after inputting the above initial conditions.

[0050] If the temperature exceeds the preset temperature value, it indicates that the air supply volume is insufficient. This can be addressed through calculation using this model. The calculation calculates the air volume based on the storage unit's temperature and the preset cooling time (e.g., 24 hours). This air volume, when applied to the actual storage unit, ensures that the unit cools from its current temperature to below the preset temperature within the preset cooling time, thus meeting the concrete's temperature requirements in steady state. Based on the calculated air volume, the air volume of the storage unit is gradually increased until the concrete temperature does not exceed the preset temperature value after reaching steady state.

[0051] In this embodiment, 3D modeling is performed using the CFD (Computational Fluid Dynamics) software ANSYS CFX. In other embodiments, other software can also be used for calculation.

[0052] In this embodiment, the temperature adjustment can be further refined. For example, when the model simulates concrete, the temperature difference (with 5℃ as one step: 65, 70, 75, 80, 85, 90℃) and the air volume value are set when the temperature value exceeds the preset temperature value. In the process of obtaining this correspondence, the air volume exceeding the normal air volume level (i.e., the ventilation air volume under normal conditions) is first selected as the initial air volume for a certain temperature. The air volume value is used to calculate the heat dissipation of the model at that temperature so that the model can reduce the temperature to the normal temperature (below the preset temperature value) within a certain time (e.g., 24 hours). If the air volume value is insufficient, the air volume is increased and iterated until a suitable air volume value is found. Finally, the temperature difference-air volume value curve is obtained as the correspondence, which serves as a reference for the air volume value used in subsequent temperature adjustment after the concrete overheats.

[0053] In this embodiment, the control unit further refines the regulation of the ventilation volume of the ventilation device based on temperature. The control unit also includes a operation detection device, and the controller is electrically connected to the operation detection device. The operation detection device is used to control the operation detection device to start when the received temperature value exceeds the preset temperature value. The operation detection device is used to detect the operating status of the ventilation device and send the detection result to the controller. When the detection result shows that the operating status of the ventilation device is normal, the controller controls the air volume of the ventilation device. When the detection result shows that the operating status of the ventilation device is abnormal or stopped, the controller generates alarm information.

[0054] That is, before adjusting the air volume, the operation of the ventilation device is checked by the operation detection device. Normal control is normal when it is running normally, and an alarm is immediately triggered when it is running abnormally or stops. Therefore, it can effectively determine whether the temperature rise of the storage system is caused by heat release from the waste bin or by the failure of the ventilation device. This avoids further activating the ventilation device when the storage unit is heated due to the failure of the ventilation device itself, which could ultimately lead to the complete damage of the ventilation device.

[0055] In this embodiment, the operation detection device can be used to detect fan failures in the ventilation system. Fan failures such as blade damage, bearing damage, and motor failure can all be detected by corresponding sensing components. These fan failure detection components are common in the field of fan failure detection on the market and will not be described in detail here. The operation detection device can also set different fault alarms and other signals for each type of fault. When connected to the controller, if no such fault alarms occur, it is considered that the ventilation system is operating stably and normally.

[0056] In summary, the ventilation equipment in this embodiment addresses various unforeseen circumstances during waste bin storage (such as temperature increases due to heat release from solid waste, temperature increases due to ventilation failure, leaks in waste bins or storage wells, and unclear leak locations) with corresponding detection methods and effective handling or alarm solutions. It boasts a high degree of automation, requires minimal manpower, and can resolve issues of excessive aerosol levels and concrete temperatures during storage. It promptly removes the decay heat of intermediate and high-level radioactive solid waste, ensuring that the concrete structure does not crumble due to overheating, thus preventing damage to the integrity of the temporary storage facility. Furthermore, it can promptly handle abnormal operating conditions in the event of aerosol leaks, preventing excessive aerosol leakage into the environment and causing air pollution, thereby improving the safety of intermediate and high-level radioactive solid waste during storage.

[0057] Example 2

[0058] The radioactive solid waste storage system of this embodiment, such as Figure 2 As shown, the system includes at least one storage unit, which comprises a storage chamber 1, storage wells 2, and ventilation equipment for the radioactive solid waste storage system of Example 1. Multiple storage wells 2 are provided and arranged within the storage chamber 1 for storing waste containers containing intermediate to high-level radioactive solid waste. Figure 2 The number of storage wells 2 is three for illustration only. More storage wells 2 can be set in the storage room 1 of the actual storage unit. The storage well 2 includes a well shaft 22 and a shielding cover plate 21. The shielding cover plate 21 is used to seal the well opening of the well shaft 22.

[0059] Storage chamber 1 is a hollow concrete structure with air inlet ducts 11 and exhaust ducts 12 on both side walls. This structure facilitates the removal of decay heat generated by intermediate and high-level radioactive solid waste through ventilation. The waste bin, as the first closed barrier for intermediate and high-level radioactive solid waste, requires a storage container with α-sealing function. Storage well 2 and storage chamber 1 serve as the second and third closed barriers, respectively. Under normal operating conditions, there are no radioactive aerosols in storage well 2 and storage chamber 1. Under abnormal operating conditions, if the waste bin and / or storage well 2 are damaged, radioactive aerosols may be present in storage well 2 and / or storage chamber 1.

[0060] In the ventilation equipment of the radioactive solid waste storage system, the air supply mechanism of the ventilation device is connected to the air inlet duct 11 to provide airflow for the ventilation of the storage room 1. The normal exhaust mechanism and the abnormal exhaust mechanism can be switched to connect to the exhaust duct 12. The normal exhaust mechanism is used to remove the decay heat of the medium and high radioactive solid waste stored in the waste bins in the waste storage unit. In addition to removing the decay heat, the abnormal exhaust mechanism is also used to intercept the radioactive aerosols carried in the exhaust air caused by abnormal operating conditions.

[0061] In this embodiment, when the radioactive solid waste storage system includes multiple storage units, the multiple storage units can be connected in parallel for ventilation through the air inlet duct 11 and the air outlet duct 12. That is, the air inlet duct 11 of each storage unit is connected to the same area or the atmosphere, and the air outlet duct 12 is connected to the same area. There is no series connection between the units, which avoids radioactive leakage to other storage units.

[0062] In this embodiment, the storage unit also includes a hoisting device 3, which is located above the storage chamber 1 and can dock with the storage well 2 to hoist the waste bins into or out of the storage well 2.

[0063] Because the sealed storage well 2 has more sealing components such as expansion joints compared to the unsealed storage well 2, the cost is higher. Therefore, in this embodiment, at least one of the multiple storage wells 2 of the storage unit is a sealed structure, and the rest are unsealed structures. Initially, the waste bins are stored in the unsealed storage well 2. The control unit is also electrically connected to the hoisting device 3 and is used to determine the location of the radioactive leak in the storage well 2 based on the level of radioactive aerosol, and to control the hoisting device 3 to hoist the waste bins in the storage well 2 where the radioactive leak is located to the sealed storage well 2.

[0064] This embodiment combines sealed and non-sealed structures, which not only enables timely transfer and sealing of leaking waste bins, but also reduces the overall cost of the storage unit.

[0065] In this embodiment, the connection between the air inlet duct 11 and the storage chamber 1, and the connection between the exhaust duct 12 and the storage chamber 1, are located at the upper and lower ends of the storage chamber 1, respectively. Figure 2 As shown, both the air inlet duct 11 and the air outlet duct 12 have a Z-shaped structure. Based on the radiation shielding effect of the concrete sidewall of the storage unit without damaging it, the Z-shaped structure prevents β / γ external radiation from directly passing through the duct. The radiation weakens after multiple reflections. Simultaneously, this structural arrangement places the connection points of the two ducts at the upper and lower ends of the storage chamber 1, respectively, creating a height difference between the air inlet and outlet. The outlet, closer to the inner wall of the storage chamber 1, is higher than the inlet. This is to account for the expansion of the incoming air due to heating, causing the hot air to rise. Exhausting from a higher position is more reasonable and facilitates sufficient heat exchange, removing heat from the storage unit.

[0066] Example 3

[0067] The radioactive solid waste storage method of this embodiment uses the storage system in Example 2, and the method specifically includes the following steps:

[0068] Turn on the ventilation equipment of the radioactive solid waste storage system, specifically, turn on the air supply mechanism, the normal exhaust mechanism, the radioactivity detection device, and the temperature detection device;

[0069] The hoisting device 3 is connected to the storage well 2, and the hoisting device 3 is controlled to hoist the waste bin into the non-sealed storage well 2.

[0070] The storage well 2 is sealed by the shielding cover plate 21;

[0071] The detection of radioactive aerosol levels in the storage unit and the processing of the detection results, specifically, the detection of radioactive aerosol levels in the storage unit by a first detection institution, including:

[0072] a. When it is determined that the level of radioactive aerosol in the storage unit has not reached the preset conditions, the abnormal ventilation mechanism is kept closed, and the normal ventilation mechanism is opened.

[0073] b. When the radioactive aerosol level in the storage unit reaches the preset condition, that is, when the first detection agency detects that the aerosol concentration in the exhaust air of storage chamber 1 exceeds the standard, it indicates that there is a leak in the waste bin and storage well 2. At this time, measures are taken in two aspects:

[0074] First, the abnormal exhaust mechanism is activated, and the normal exhaust mechanism is closed to reduce the aerosol concentration. Second, the second detection mechanism is activated to sample and measure the gas in each storage well 2. When the concentration of radioactive aerosol in a certain storage well 2 exceeds the standard, the hoisting device 3 is controlled to hoist the waste container in the storage well 2 where the radioactive leak occurred to the sealed storage well 2. Even if some waste containers are damaged, because they have been placed in the safe storage well 2, the excessive radioactive aerosol will not leak into the storage room 1 and be carried away by the exhaust to pollute the environment.

[0075] c. Once the radioactive aerosol level in the storage unit returns to normal, switch the abnormal ventilation mechanism back to the normal ventilation mechanism, i.e., keep the abnormal ventilation mechanism closed and the normal ventilation mechanism open.

[0076] The temperature of the storage unit is detected and processed according to the detection results. Specifically, the temperature of the storage unit is detected by a temperature detection device. When the temperature of the concrete exceeds the preset temperature value, corresponding measures are taken according to the following situations:

[0077] a. If the components of the air supply mechanism and the normal exhaust mechanism are operating normally, the reason for the rise in concrete temperature is that the decay heat generated by the medium and high radioactive solid waste in the waste storage unit is higher than the design value. In this case, it is necessary to increase the number of air exchanges in the normal ventilation to remove more heat.

[0078] b. If the air supply mechanism and normal exhaust mechanism malfunction or stop operating due to component failure or power supply failure, an alarm message will be generated in a timely manner. The equipment needs to be inspected and repaired as soon as possible, and backup equipment or backup power should be put into operation to restore normal ventilation.

[0079] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A ventilation system for a radioactive solid waste storage system, installed within each storage unit of the system, characterized in that: Includes control unit and ventilation device, The ventilation system includes a normal exhaust mechanism and an abnormal exhaust mechanism. The normal ventilation system is used to ventilate the storage unit when it is not radioactive. The abnormal ventilation mechanism is used to ventilate the storage unit when it is radioactive, while simultaneously filtering radioactive aerosols from the ventilation airflow. The control unit is electrically connected to the ventilation device and is used to control the switching between the normal exhaust mechanism and the abnormal exhaust mechanism according to the level of radioactive aerosol in the storage unit, and to control the air volume of the ventilation device according to the temperature of the storage unit. The control unit includes a radioactivity detection device and a controller. The radioactivity detection device is electrically connected to the controller and is used to detect the level of radioactive aerosols in the storage unit and send it to the controller. The controller is used to determine whether a preset condition has been met based on the received level of radioactive aerosols, and when the determination result is that the level of radioactive aerosols has met the preset condition, it controls the abnormal ventilation mechanism to open and controls the normal ventilation mechanism to close; and when the determination result is that the received level of radioactive aerosols has not met the preset condition, it keeps the abnormal ventilation mechanism closed and controls the normal ventilation mechanism to open. The radioactivity detection device includes a first detection mechanism and a second detection mechanism. The first detection mechanism is located in the exhaust duct (12) of the storage unit. Multiple second testing agencies are used, and each of the multiple second testing agencies is set up in a storage well (2) in the storage unit. The controller is electrically connected to the first and second detection mechanisms, respectively, and is used to determine whether a preset condition has been met based on the level of radioactive aerosols detected by the first detection mechanism. When the level of radioactive aerosols reaches the preset condition, the controller controls the second detection mechanism to start. The controller is also used to determine the location of the radioactive leak in the storage well (2) based on the radioactive aerosol levels detected by each of the second detection agencies and to generate alarm information.

2. The ventilation equipment for the radioactive solid waste storage system according to claim 1, characterized in that: The preset conditions include an α radioactivity concentration exceeding 0.06 Bq / m³ and / or a β radioactivity concentration exceeding 15 Bq / m³.

3. The ventilation equipment for the radioactive solid waste storage system according to claim 1, characterized in that: The control unit includes a temperature detection device and a controller. The temperature detection device is electrically connected to the controller and is used to detect the temperature value of the storage unit and send it to the controller. The controller is used to compare the received temperature value with the preset temperature value stored in its internal storage, and to control the air volume of the ventilation device accordingly when the temperature value exceeds the preset temperature value.

4. The ventilation equipment for the radioactive solid waste storage system according to claim 3, characterized in that: The control unit also includes a model analysis device. The model analysis device is electrically connected to the controller and contains a model corresponding to the storage unit. The controller is used to send the received temperature value to the model analysis device when the temperature value exceeds a preset temperature value. The model analysis device is used to analyze the temperature value and the preset cooling time to obtain the airflow value corresponding to the storage unit reaching a temperature below the preset value within the preset cooling time, and then sends it to the controller. The controller controls the airflow of the ventilation device according to the airflow value.

5. The ventilation equipment for the radioactive solid waste storage system according to claim 3 or 4, characterized in that: The control unit also includes an operation detection device. The controller is also electrically connected to the operation detection device, and is used to control the operation detection device to start when the received temperature value exceeds a preset temperature value. The operation detection device is used to detect the operating status of the ventilation system and send the detection results to the controller. The controller is also used to control the air volume of the ventilation device when the detection result indicates that the ventilation device is operating normally, and to generate alarm information when the detection result indicates that the ventilation device is operating abnormally or has stopped operating.

6. The ventilation equipment for the radioactive solid waste storage system according to claim 1, characterized in that: The ventilation device also includes an air supply mechanism, which is connected to the air inlet duct (11) of the storage unit and is used to provide airflow for the ventilation of the storage unit. The control unit is electrically connected to the air supply mechanism and is used to control the air volume of the air supply mechanism according to the temperature of the storage unit, so as to control the air volume of the ventilation device.

7. A radioactive solid waste storage system, characterized in that: It includes at least one storage unit, said storage unit comprising a storage chamber (1), a storage well (2), and ventilation equipment for the radioactive solid waste storage system according to any one of claims 1 to 6. Multiple storage wells (2) are provided and arranged in the storage room (1) for storing waste bins. The storage room (1) has an air inlet duct (11) and an air outlet duct (12) on its wall. In the ventilation equipment of the radioactive solid waste storage system, the normal exhaust mechanism and the abnormal exhaust mechanism can be switched to connect to the exhaust duct (12).

8. The radioactive solid waste storage system according to claim 7, characterized in that: The storage unit also includes a hoisting device (3). The hoisting device (3) is located above the storage chamber (1) and is used to hoist the waste bins into or out of the storage well (2).

9. The radioactive solid waste storage system according to claim 8, characterized in that: Of the multiple storage wells (2), at least one is a sealed structure, and the rest are unsealed structures. The waste bins are stored in a non-sealed storage well (2). The control unit is also electrically connected to the hoisting device (3) and is used to determine the location of the radioactive leak in the storage well (2) based on the level of radioactive aerosols, and to control the hoisting device (3) to hoist the waste bucket in the storage well (2) where the radioactive leak is located to the sealed storage well (2).

10. The radioactive solid waste storage system according to claim 7, characterized in that: The connection between the air inlet duct (11) and the storage chamber (1) and the connection between the exhaust duct (12) and the storage chamber (1) are located at the upper and lower ends of the storage chamber (1), respectively.

11. A method for storing radioactive solid waste, characterized in that, The method using the radioactive solid waste storage system of claim 9 specifically includes the following steps: Turn on the ventilation equipment of the radioactive solid waste storage system; Control the hoisting device (3) to hoist the waste bin into the non-sealed storage well (2); Sealed storage well (2); The detection and processing of radioactive aerosol levels in the storage unit includes: a. When it is determined that the level of radioactive aerosol in the storage unit has not reached the preset conditions, the abnormal ventilation mechanism is kept closed, and the normal ventilation mechanism is opened. b When the level of radioactive aerosol in the storage unit is determined to meet the preset conditions, the abnormal ventilation mechanism is opened and the normal ventilation mechanism is closed. The hoisting device (3) is used to hoist the waste bucket in the storage well (2) where the radioactive leak is located to the sealed storage well (2).

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