Trolley device for removing residual tritium in filter element of heavy water reactor waste filter

Abstract

The invention relates to the technical field of radioactive waste management, and particularly discloses a trolley device for removing residual tritium in a filter element of a heavy water reactor waste filter. The device comprises a trolley barrel, a molecular sieve absorption chamber and a tail gas treatment filter which are sequentially connected, a heating part is arranged in the trolley barrel, a weight monitor is arranged at the bottom, and a barrel air outlet is formed in the right end; the trolley cylinder conveys tritium-containing steam to a molecular sieve absorption chamber through a cylinder gas outlet, a plurality of molecular sieves are arranged in the molecular sieve absorption chamber, the tritium-containing steam is adsorbed, and tail gas is formed; tail gas is conveyed to the tail gas treatment filter through a pipeline, a plurality of filter pieces are arranged in the tail gas treatment filter to supplement and absorb the tail gas, and a tail gas monitor is arranged at an outlet of the tail gas treatment filter. According to the device, in the process of transferring, collecting and storing the waste filter element, the waste filter element to be treated can be lifted and loaded into the trolley to be subjected to tritium removal treatment, and the tritium water content of the waste filter element can be greatly reduced after treatment, so that the waste filter element meets related treatment requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of radioactive waste management, and in particular relates to a trolley device for removing residual tritium from a filter element of a waste filter of a heavy water reactor. Background Art

[0002] Qinshan Phase III Heavy Water Reactor Nuclear Power Plant (hereinafter referred to as "Qinshan Phase III") is equipped with two 700MWe CANDU-6 pressurized heavy water reactors imported from Canada. Each unit has 7 systems equipped with water filters, which are important equipment in the nuclear island radioactive water treatment system. In the water use process of the reactor primary loop and related systems, the water filter filters suspended matter and other impurities to ensure the stable operation of the unit and related systems; in the drainage process of the primary loop sewage system and waste liquid treatment system, the radioactivity and chemical content of the waste liquid are reduced to ensure that the waste liquid discharge meets the local environmental protection policy.

[0003] The filter element needs to be replaced regularly or when the pressure difference reaches the set value. According to the regulations of the power station, if the contact dose rate of the waste filter element (hereinafter referred to as "waste filter element") is greater than 2mSv / h, it needs to be placed in a shielding container and transported to the waste storage warehouse for temporary storage.

[0004] Since the waste filter elements that are transported, collected and temporarily stored in the temporary storage warehouse have a high dose rate and contain a large amount of tritium water, personnel cannot directly contact and handle the waste filter elements at close range. The transportation and storage of waste filter elements are generally achieved through devices or in combination with the use of overhead cranes. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a trolley device for removing residual tritium from a waste filter element of a heavy water reactor in view of the above-mentioned deficiencies in the prior art, so as to solve the problems of transporting, storing and removing residual tritium from waste filter elements.

[0006] In order 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 reactor waste filter element, the device comprising a trolley cylinder, a molecular sieve absorption chamber, and an exhaust gas treatment filter, wherein the trolley cylinder, the molecular sieve absorption chamber, and the exhaust gas treatment filter are connected in sequence; the trolley cylinder has a built-in heating unit, a weight monitor is provided at the bottom, and a cylinder air outlet is provided at the right end; the trolley cylinder transports tritium-containing steam to the molecular sieve absorption chamber through the cylinder air outlet, the molecular sieve absorption chamber has a plurality of molecular sieves built in, the tritium-containing steam is adsorbed, and exhaust gas is formed; the exhaust gas is transmitted to the exhaust gas treatment filter through a pipeline, the exhaust gas treatment filter has a plurality of filter sheets built in, the exhaust gas treatment filter supplementarily absorbs the exhaust gas, and an exhaust gas monitor is provided at the outlet of the exhaust gas treatment filter.

[0007] An external air hole is opened on the left side of the trolley cylinder, and pressurized gas is provided to the trolley cylinder 2 through the external air hole.

[0008] The external air hole is connected to the external gas cylinder.

[0009] A cylinder air inlet is provided on the right side of the cylinder of the trolley.

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

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

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

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

[0014] The heating temperature range in the cylinder of the trolley is 105°C-115°C.

[0015] The remarkable effect of the present invention is that the residual tritium removal trolley device of the heavy water reactor waste filter element of the present invention, after the tritium-containing steam is precipitated by heating the trolley cylinder, is adsorbed by two stages of molecular sieve absorption chamber and tail gas treatment filter, and is also monitored before tail gas emission, and the tail gas that does not meet the standard is re-adsorbed to ensure the quality of tail gas emission; the trolley cylinder determines the precipitation process of tritium-containing steam by measuring the weight, and then determines the treatment of residual tritium. The device has a simple structure and reliable functions. During the process of transporting and storing the waste filter element, the waste filter element to be treated can be lifted and loaded into the trolley for detritium treatment. After treatment, the tritium water content of the waste filter element can be greatly reduced to meet the relevant disposal requirements. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 2 This is an operation flow chart of a trolley device for removing residual tritium from a heavy water reactor waste filter element according to the present invention;

[0018] In the figure: 1. External gas cylinder; 2. Trolley cylinder; 3. Molecular sieve absorption chamber; 4. Exhaust gas treatment filter; 5. First valve; 6. Thermometer; 7. First pressure gauge; 8. Second pressure gauge; 9. One-way valve. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of the present invention.

[0020] In the description of the present invention, it should be noted that the directions or positional relationships indicated by “upper” and the like are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

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

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0023] like Figure 1 As shown, a trolley device for removing residual tritium from a waste filter element of a heavy water reactor comprises a trolley cylinder 2, a molecular sieve absorption chamber 3, and an exhaust gas treatment filter 4. The trolley cylinder 2, the molecular sieve absorption chamber 3, and the exhaust gas treatment filter 4 are sequentially connected from left to right and placed on a trolley for easy movement. The trolley cylinder 2 has a built-in heating unit. After the waste filter element is placed in the trolley cylinder 2, the heating unit is started to control the temperature in the cylinder to be maintained at 105°C-115°C, so that the waste filter element precipitates tritium-containing steam; an external air hole is provided on the left side of the trolley cylinder 2, and pressurized gas is provided to the trolley cylinder 2 through the external air hole to provide movement power for the tritium-containing steam; a cylinder air outlet and a cylinder air inlet are provided on the right side of the trolley cylinder 2, and the cylinder air outlet is connected to the molecular sieve absorption chamber 3 through a second valve, so that the tritium-containing steam enters the molecular sieve absorption chamber 3 through the second valve;

[0024] The molecular sieve absorption chamber 3 has a plurality of molecular sieves built therein. When the tritium-containing steam passes through the molecular sieve absorption chamber 3, the molecular sieves adsorb the tritium water vapor. The right side of the molecular sieve absorption chamber 3 is connected to the tail gas treatment filter 4 through a third valve.

[0025] The exhaust gas treatment filter 4 is equipped with a plurality of filter sheets to supplement the exhaust gas delivered from the molecular sieve absorption chamber 3; an exhaust gas monitor is provided at the exhaust gas outlet of the exhaust gas treatment filter 4. If the exhaust gas monitoring fails, the exhaust gas is discharged into the cylinder 2 of the trolley through the cylinder air inlet, and the exhaust gas is re-adsorbed and filtered. If the exhaust gas monitoring passes, it is directly discharged or discharged into the vent;

[0026] The external air hole 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. As an embodiment, the inert gas is nitrogen. As 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-containing steam to move toward the molecular sieve absorption chamber 3.

[0027] The trolley cylinder 2 is provided with a thermometer 6 to monitor the temperature inside the trolley cylinder 2; a weight monitor is provided at the bottom of the trolley cylinder 2 to monitor the weight of the waste filter element. When there is no significant change in the weight of the waste filter element, the heating in the trolley cylinder 2 is stopped to complete the removal of residual tritium in the waste filter element;

[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 air inlet of the trolley cylinder 2 through a pipeline, and 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 operation steps of a trolley device for removing residual tritium from a heavy water reactor waste filter element are as follows:

[0031] Step 1: After placing a number of 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 the gas cylinder 1 (the second and third valves are closed at this time), fill the trolley cylinder with gas, and close the first valve when the pressure of the first barometer 7 reaches 0.05±0.01MPa, and maintain the pressure for 30 minutes to detect leaks in the trolley cylinder; after the trolley cylinder leak detection is completed, open the second valve, and close the second valve when the pressure of the second barometer reaches 0.03±0.01MPa, and maintain the pressure for 30 minutes to detect leaks in the molecular sieve absorption chamber 3; after the leak detection is completed, the third valve discharges the gas;

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

[0033] Step 3: Turn on the heating part of the cylinder 2 of the trolley, and control the temperature in the cylinder to be maintained within the range of 105°C-115°C, so that the waste filter element precipitates tritium-containing steam, and the tritium-containing steam passes through the molecular sieve absorption chamber 3 to adsorb the tritium-containing steam to form tail gas;

[0034] Step 4: After the exhaust gas is supplementally absorbed by the exhaust gas treatment filter 4, if the exhaust gas monitoring is unqualified, the exhaust gas is discharged into the trolley cylinder 2 through the cylinder air inlet, and the exhaust gas is re-adsorbed and filtered. If the exhaust gas monitoring is qualified, it is directly discharged or discharged into the vent;

[0035] Step 5: When there is no significant change in the weight of the waste filter element in the cylinder 2 of the trolley, the heating is stopped, and the removal of residual tritium in the waste filter element is completed;

[0036] Step 6: Place the treated waste filter element into a disposal pit for temporary storage or transport it to a designated location for inspection and delivery. The molecular sieve in the molecular sieve absorption chamber 3 is placed in a waste barrel for sealed temporary storage or cement fixation.

[0037] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A trolley device for removing residual tritium from a heavy water reactor waste filter element, characterized in that: The device comprises a trolley cylinder (2), a molecular sieve absorption chamber (3), and an exhaust gas treatment filter (4), wherein the trolley cylinder (2), the molecular sieve absorption chamber (3), and the exhaust gas treatment filter (4) are connected in sequence; the trolley cylinder (2) has a built-in heating unit, a weight monitor is provided at the bottom, and a cylinder gas outlet is provided at the right end; the trolley cylinder (2) transports tritium-containing steam to the molecular sieve absorption chamber (3) through the cylinder gas outlet, the molecular sieve absorption chamber (3) has a plurality of molecular sieves built in, which adsorb the tritium-containing steam and form exhaust gas; the exhaust gas is transported to the exhaust gas treatment filter (4) through a pipeline, the exhaust gas treatment filter (4) has a plurality of filter sheets built in, which supplement the exhaust gas absorption, and an exhaust gas monitor is provided at the outlet of the exhaust gas treatment filter (4).

2. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 1, characterized in that: An external air hole is provided on the left side of the trolley cylinder (2), and pressurized gas is provided to the trolley cylinder 2 through the external air hole.

3. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 2, characterized in that: The external gas hole is connected to the external gas cylinder (1).

4. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 1, characterized in that: A cylinder air inlet is provided on the right side of the trolley cylinder (2).

5. A trolley device for removing residual tritium from a heavy water reactor waste filter element according to claim 4, characterized in that: The outlet of the exhaust gas treatment filter (4) is connected to the right cylinder air inlet of the trolley cylinder (2) via a one-way valve (9).

6. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 3, characterized in that: The trolley cylinder (2) is connected to the external gas cylinder (1) via a first valve (5).

7. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 1, characterized in that: The trolley cylinder (2) and the molecular sieve absorption chamber (3) are connected via a second valve, and the second valve is also connected to a first air pressure gauge (7).

8. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 1, characterized in that: The molecular sieve absorption chamber (3) and the tail gas treatment filter (4) are connected via a third valve, and the third valve is also connected to a second air pressure gauge (8).

9. The device for removing residual tritium from a heavy water reactor waste filter cartridge according to claim 1, characterized in that: The heating temperature in the trolley cylinder (2) ranges from 105°C to 115°C.

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