A trolley device for removing residual tritium from heavy water stack waste filter cartridges

Abstract

This invention relates to the field of radioactive waste management technology, specifically disclosing a trolley device for removing residual tritium from heavy water reactor waste filter cartridges. The device comprises a trolley body, a molecular sieve absorption chamber, and a tail gas treatment filter, connected in sequence. The trolley body has a built-in heating element, a weight monitor at the bottom, and a gas outlet at the right end. The trolley body transports tritium-containing vapor to the molecular sieve absorption chamber through the outlet. The molecular sieve absorption chamber contains several molecular sieves that adsorb the tritium-containing vapor, forming tail gas. The tail gas is transmitted through a pipeline to the tail gas treatment filter, which contains several filter elements for supplementary absorption. A tail gas monitor is located at the outlet of the tail gas treatment filter. This device allows the waste filter cartridges to be treated to be lifted and loaded into the trolley for tritium removal during transport and storage. After treatment, the tritium water content of the waste filter cartridges can be significantly reduced, making them meet relevant disposal requirements.

Description

Technical Field

[0001] This invention belongs to the field of radioactive waste management technology, specifically relating to a device for removing residual tritium from heavy water reactor waste filter cartridges. Background Technology

[0002] The Qinshan Phase III Heavy Water Reactor Nuclear Power Plant (hereinafter referred to as "Qinshan Phase III") consists of two 700MWe CANDU-6 pressurized heavy water reactors imported from Canada. Each unit has seven systems equipped with water filters. These water filters are crucial equipment in the nuclear island's radioactive water treatment system. They filter suspended solids and other impurities in the reactor's primary loop and related systems' water usage processes, ensuring the stable operation of the unit and related systems. In the primary loop's wastewater discharge system and wastewater treatment system, they reduce the radioactivity and chemical content of the wastewater.

[0003] Filter cartridges need to be replaced periodically or when the differential pressure reaches a set value. According to power plant regulations, waste filter cartridges (hereinafter referred to as "waste cartridges") with a contact dose rate greater than 2 mSv / h need to be placed in a shielded container and transported to a waste temporary storage facility for temporary storage.

[0004] Because the waste filter cartridges transferred, collected, and temporarily stored in the temporary storage facility have a high dose rate and contain a large amount of tritium water, personnel cannot directly and closely contact and handle the waste filter cartridges. The transfer and collection of waste filter cartridges are generally achieved through equipment or by using overhead cranes. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a trolley device for removing residual tritium from waste filter cartridges in heavy water reactors, thereby solving the problems of waste filter cartridge transportation, storage and removal of residual tritium.

[0006] To solve the above problems, the technical solution of the present invention is as follows: a trolley device for removing residual tritium from a heavy water stack waste filter element, the device comprising a trolley body, a molecular sieve absorption chamber, and a tail gas treatment filter, wherein the trolley body, the molecular sieve absorption chamber, and the tail gas treatment filter are connected in sequence; the trolley body has a built-in heating element, a weight monitor at the bottom, and a trolley outlet at the right end; the trolley body transports tritium-containing vapor to the molecular sieve absorption chamber through the trolley outlet, the molecular sieve absorption chamber contains several molecular sieves to adsorb the tritium-containing vapor and form tail gas; the tail gas is transmitted to the tail gas treatment filter through a pipeline, the tail gas treatment filter contains several filter plates to supplement the absorption of the tail gas, and a tail gas monitor is provided at the outlet of the tail gas treatment filter.

[0007] An external air inlet is provided on the left side of the trolley cylinder 2, through which pressurized gas is supplied to the trolley cylinder 2.

[0008] The external air inlet is connected to an external gas cylinder.

[0009] The trolley body has an air inlet on its right side.

[0010] The outlet of the exhaust gas treatment filter is connected to the air inlet of the right side of the trolley cylinder via a one-way valve.

[0011] The trolley body is connected to the external gas cylinder via a first valve.

[0012] The trolley cylinder and the molecular sieve absorption chamber are connected by a second valve, which is also connected to a first pressure gauge.

[0013] The molecular sieve absorption chamber and the exhaust gas treatment filter are connected by a third valve, which is also connected to a second pressure gauge.

[0014] The heating temperature range inside the trolley cylinder is 105℃-115℃.

[0015] The significant advantages of this invention are as follows: The heavy water stack waste filter cartridge residual tritium removal trolley device of this invention, through heating the trolley cylinder to precipitate tritium-containing vapor, then adsorbs it through a two-stage process of molecular sieve absorption chamber and tail gas treatment filter. Before tail gas emission, monitoring is performed, and substandard tail gas is re-adsorbed to ensure tail gas emission quality. The trolley cylinder determines the tritium vapor precipitation process by measuring its weight, thereby assessing the residual tritium treatment status. This device has a simple structure and reliable function. During the transfer and storage of waste filter cartridges, the waste filter cartridges to be treated can be lifted and loaded into the trolley for tritium removal treatment, significantly reducing the tritium water content of the waste filter cartridges to meet relevant disposal requirements. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a trolley device for removing residual tritium from a heavy water waste filter cartridge according to the present invention;

[0017] Figure 2 This is a flowchart illustrating the operation of a heavy water waste filter cartridge residual tritium removal trolley device according to the present invention.

[0018] In the diagram: 1. External gas cylinder; 2. Cart body; 3. Molecular sieve absorption chamber; 4. Tail gas treatment filter; 5. First valve; 6. Thermometer; 7. First pressure gauge; 8. Second pressure gauge; 9. One-way valve. Detailed Implementation

[0019] 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.

[0020] In the description of this invention, it should be noted that the use of terms such as "above" to indicate orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating and simplifying the description. It does 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, and therefore should not be construed as a limitation of this invention.

[0021] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] 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.

[0023] like Figure 1 As shown, a trolley device for removing residual tritium from waste filter cartridges in heavy water reactors is disclosed. The device includes a trolley body 2, a molecular sieve absorption chamber 3, and a tail gas treatment filter 4. The trolley body 2, molecular sieve absorption chamber 3, and tail gas treatment filter 4 are connected sequentially from left to right and placed on the trolley for easy movement. The trolley body 2 has a built-in heating unit. After the waste filter cartridge is placed inside the trolley body 2, the heating unit is activated to maintain the temperature inside the cylinder at 105℃-115℃, causing the waste filter cartridge to release tritium-containing vapor. An external air inlet is provided on the left side of the trolley body 2 to supply pressurized gas and provide the propulsion for the tritium-containing vapor. An air outlet and an air inlet are provided on the right side of the trolley body 2. The air outlet is connected to the molecular sieve absorption chamber 3 via a second valve, allowing the tritium-containing vapor to enter the molecular sieve absorption chamber 3 through the second valve.

[0024] The molecular sieve absorption chamber 3 contains several molecular sieves. When tritium vapor passes through the molecular sieve absorption chamber 3, the molecular sieves adsorb the tritium vapor. The right side of the molecular sieve absorption chamber 3 is connected to the exhaust gas treatment filter 4 through a third valve.

[0025] The exhaust gas treatment filter 4 has several filter plates built in to supplement the absorption of the exhaust gas delivered from the molecular sieve absorption chamber 3; the exhaust gas treatment filter 4 is equipped with an exhaust gas monitor at the exhaust gas outlet. If the exhaust gas monitoring fails, the exhaust gas is discharged into the trolley cylinder 2 through the cylinder inlet to re-adsorb and filter the exhaust gas. If the exhaust gas monitoring passes, it is directly discharged or discharged into the ventilation port.

[0026] The external air inlet on the left side of the trolley cylinder 2 is connected to the external gas cylinder 1 through the first valve 5. The external gas cylinder 1 contains pressurized inert gas. In one embodiment, the inert gas is nitrogen. In another embodiment, the inert gas is carbon dioxide. By opening the first valve 5, the inert gas in the external gas cylinder 1 enters the trolley cylinder 2, pushing the tritium vapor to move towards the molecular sieve absorption chamber 3.

[0027] The trolley cylinder 2 is equipped with a thermometer 6 to monitor the temperature inside the trolley cylinder 2; a weight monitor is equipped at the bottom of the trolley cylinder 2 to monitor the weight of the waste filter element. When the weight of the waste filter element does not change significantly, the heating inside the trolley cylinder 2 stops, and the waste filter element residual tritium removal process is completed.

[0028] The second valve is also connected to a first pressure gauge 7 to monitor the gas pressure passing through the second valve; the third valve is also connected to a second pressure gauge 8 to monitor the gas pressure passing through the third valve.

[0029] The exhaust gas outlet of the exhaust gas treatment filter 4 is connected to the cylinder inlet of the trolley cylinder 2 via a pipeline. A one-way valve 9 is provided on the pipeline to prevent the gas discharged from the exhaust gas treatment filter 4 from flowing back.

[0030] like Figure 2 As shown, the operating steps of a heavy water stack waste filter cartridge residual tritium removal trolley device are as follows:

[0031] Step 1: After placing several molecular sieves in the molecular sieve absorption chamber 3, close the molecular sieve absorption chamber and the trolley cylinder. Open the first valve 5 and gas cylinder 1 (at this time, the second and third valves are closed), and fill the trolley cylinder with gas. When the pressure on the first pressure gauge 7 reaches 0.05±0.01MPa, close the first valve and maintain the pressure for 30 minutes to check for leaks in the trolley cylinder. After the leak check of the trolley cylinder is completed, open the second valve. When the pressure on the second pressure gauge reaches 0.03±0.01MPa, close the second valve and maintain the pressure for 30 minutes to check for leaks in the molecular sieve absorption chamber 3. After the leak check is completed, release the gas through the third valve.

[0032] Step 2: Move the trolley to the top of the waste filter temporary storage pit, open the top cover of the storage pit, grab the waste filter and lift it into the trolley cylinder 2, and seal the cylinder;

[0033] Step 3: Turn on the heating section of the trolley cylinder 2 and control the temperature inside the cylinder to be maintained within the range of 105℃-115℃, so that the waste filter element releases tritium vapor. The tritium vapor passes through the molecular sieve absorption chamber 3, where it is adsorbed to form exhaust gas.

[0034] Step 4: After the exhaust gas is absorbed by the exhaust gas treatment filter 4, if the exhaust gas monitoring fails, the exhaust gas will be discharged into the trolley cylinder 2 through the cylinder inlet to re-adsorb and filter the exhaust gas. If the exhaust gas monitoring passes, it will be directly discharged or discharged into the ventilation port.

[0035] Step 5: When the weight of the waste filter element inside the trolley cylinder 2 does not change significantly, stop heating to complete the removal of residual tritium from the waste filter element;

[0036] Step Six: Place the treated waste filter cartridges into the disposal pit for temporary storage or transport them to a designated location for testing and disposal. The molecular sieves in the molecular sieve absorption chamber 3 are placed into a waste bin for temporary storage or fixed with cement.

[0037] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A device for removing residual tritium from heavy water waste filter cartridges, characterized in that: The device includes a trolley cylinder (2), a molecular sieve absorption chamber (3), and a tail gas treatment filter (4), which are connected in sequence. The trolley cylinder (2) has a built-in heating element, a weight monitor at the bottom, and a cylinder outlet at the right end. The trolley cylinder (2) transports tritium-containing vapor to the molecular sieve absorption chamber (3) through the cylinder outlet. The molecular sieve absorption chamber (3) contains several molecular sieves to adsorb the tritium-containing vapor and form tail gas. The tail gas is transmitted to the tail gas treatment filter (4) through a pipeline. The tail gas treatment filter (4) contains several filter plates to supplement the absorption of the tail gas. A tail gas monitor is provided at the outlet of the tail gas treatment filter (4). An external air inlet is provided on the left side of the trolley cylinder (2) to provide pressurized gas to the trolley cylinder (2); The external air inlet is connected to the external gas cylinder (1); The trolley cylinder (2) is connected to the external gas cylinder (1) through the first valve (5); The trolley cylinder (2) and the molecular sieve absorption chamber (3) are connected by a second valve, and the second valve is also connected to a first pressure gauge (7); The molecular sieve absorption chamber (3) and the tail gas treatment filter (4) are connected by a third valve, and the third valve is also connected to a second pressure gauge (8); Step 1: After placing several molecular sieves in the molecular sieve absorption chamber (3), close the molecular sieve absorption chamber (3) and the trolley cylinder (2), open the first valve (5) and the gas cylinder (1), at which time the second and third valves are closed, and fill the trolley cylinder (2) with gas. When the pressure of the first pressure gauge (7) reaches 0.05±0.01MPa, close the first valve (5) and maintain the pressure for 30 minutes to check for leaks in the trolley cylinder (2); after the leak check of the trolley cylinder (2) is completed, open the second valve, and when the pressure of the second pressure gauge (8) reaches 0.03±0.01MPa, close the second valve and maintain the pressure for 30 minutes to check for leaks in the molecular sieve absorption chamber (3); after the leak check is completed, discharge the gas through the third valve. Step 2: Move the trolley to the top of the waste filter temporary storage pit, open the top cover of the storage pit, grab the waste filter and lift it into the trolley cylinder (2), and seal the cylinder; Step 3: Turn on the heating section of the trolley cylinder (2) and control the temperature inside the cylinder to be maintained within the range of 105℃-115℃, so that the waste filter element releases tritium vapor. The tritium vapor passes through the molecular sieve absorption chamber (3) to adsorb the tritium vapor and form tail gas. Step 4: After the exhaust gas is absorbed by the exhaust gas treatment filter (4), if the exhaust gas monitoring fails, the exhaust gas will be discharged into the trolley cylinder (2) through the cylinder inlet to re-adsorb and filter the exhaust gas. If the exhaust gas monitoring passes, it will be directly discharged or discharged into the ventilation port. Step 5: When the weight of the waste filter element inside the trolley cylinder (2) does not change significantly, stop heating to complete the waste filter element residual tritium removal process; Step 6: Place the treated waste filter cartridges into the disposal pit for temporary storage or transport them to a designated location for testing and disposal. The molecular sieve in the molecular sieve absorption chamber (3) is placed into a waste bin for temporary storage or fixed with cement.

2. The heavy water waste filter cartridge residual tritium removal trolley device according to claim 1, characterized in that: The trolley cylinder (2) has an air inlet on its right side.

3. The heavy water waste filter cartridge residual tritium removal trolley device according to claim 1, characterized in that: The outlet of the exhaust gas treatment filter (4) is connected to the air inlet of the right side of the trolley cylinder (2) via a one-way valve (9).

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