Chemical interaction reaction device for out-of-pile fuel cladding

Abstract

The utility model discloses a chemical interaction reaction device for an ex-reactor fuel cladding. The chemical interaction reaction device comprises a reaction cavity, an argon supply unit for providing argon, an oxygen supply unit for providing oxygen and an oxygen control unit, the argon supply unit is respectively connected with the reaction cavity and the oxygen supply unit; the oxygen supply unit is connected with the reaction cavity, and oxygen and argon from the argon supply unit are mixed and then conveyed into the reaction cavity; the oxygen control unit is used for detecting the oxygen content in the reaction cavity and controlling the oxygen supply unit to start and stop according to the oxygen content. According to the utility model, the argon supply unit, the oxygen supply unit and the oxygen control unit are matched, so that the conveying flow of argon-oxygen mixed gas can be controlled and adjusted, the oxygen content in the reaction cavity is controlled, and the oxygen content in a fuel-cladding gap under different burnup in a reactor is effectively simulated; the oxygen content balance in the reaction cavity can be prevented from being damaged by volatile fission products Cs and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to nuclear fuel technical field especially relates to a chemical interaction reaction device of out of pile fuel cladding. BACKGROUND

[0002] Oxide fuel and stainless steel cladding will have chemical interaction (Fuel cladding chemical interaction, hereinafter referred to as FCCI) under irradiation and high temperature environment, causing the corrosion of the inner wall of the cladding, thereby affecting the performance of the cladding, limiting the service life of the fuel element, and reducing the economy of the reactor operation, so the anti-FCCI performance of the cladding needs to be characterized. Out of pile FCCI test is an effective means to study the anti-FCCI performance of the cladding. For example, the paper "The corrosion product of Cs-Te corrosive compound with 11Cr-Ferritic / Martensitic Steel and 9Cr-Oxide Dispersion Strengthened steel" discloses a typical out of pile FCCI reaction device at home and abroad, the method is to put the cladding material and fuel fission products Cs, Te and the like into a crucible, and put the crucible and metal / metal oxide oxygen buffer into a single-sided closed quartz tube; the other side of the opening of the quartz tube is sealed with an isolation valve, and heated in a high temperature furnace to carry out out of pile FCCI test. Among them, the test puts different kinds of metal / metal oxide oxygen buffers (Mo / MoO3, Cr / Cr2O3, etc.), so as to change the oxygen content in the out of pile FCCI reaction device.

[0003] Because the prior art generally uses metal / metal oxide oxygen buffer to simulate the oxygen content (i.e. oxygen potential) in the fuel-cladding gap under a certain burnup in the reactor, it cannot simulate the change of the oxygen content in the fuel-cladding gap in the reactor with the burnup, so it cannot further study the influence of the change of the oxygen content on the corrosion of the inner wall of the cladding during the irradiation of the fuel. UTILITY MODEL CONTENT

[0004] The technical problem to be solved by the utility model is to provide an improved out of pile fuel cladding chemical interaction reaction device.

[0005] The technical scheme adopted by the utility model to solve its technical problem is: an out of pile fuel cladding chemical interaction reaction device is provided, which comprises a reaction cavity for placing a cladding test piece and a corrosive medium, an argon supply unit for providing argon, an oxygen supply unit for providing oxygen, and an oxygen control unit.

[0006] The argon supply unit is connected with the reaction cavity and the oxygen supply unit respectively; the oxygen supply unit is connected with the reaction cavity, and oxygen is mixed with argon from the argon supply unit and then delivered into the reaction cavity.

[0007] The oxygen control unit is used for detecting the oxygen content in the reaction cavity and controlling the start and stop of the oxygen supply unit according to the oxygen content.

[0008] Preferably, the reaction cavity comprises a high-temperature furnace and an alumina crucible arranged in the high-temperature furnace and used for accommodating a cladding test piece and a corrosive medium.

[0009] Preferably, the argon supply unit comprises an argon source, a first argon pipeline connected between the argon source and the reaction cavity, and a second argon pipeline connected between the argon source and the oxygen supply unit.

[0010] Preferably, the oxygen supply unit comprises an oxygen source and an oxygen pipeline connected between the oxygen source and the reaction cavity; the second argon pipeline is connected between the argon source and the oxygen pipeline.

[0011] Preferably, the oxygen supply unit further comprises a mixing cavity used for mixing argon and oxygen to form argon-oxygen mixed gas, and the mixing cavity is arranged on the oxygen pipeline; the second argon pipeline is connected between the argon source and the mixing cavity.

[0012] Preferably, the out-of-pile fuel cladding chemical interaction reaction device further comprises a vacuum pump connected with the reaction cavity through a vacuum pipeline.

[0013] Preferably, the out-of-pile fuel cladding chemical interaction reaction device further comprises a circulating fan used for driving the circulation flow of gas in the reaction cavity.

[0014] Preferably, the circulating fan is arranged in the reaction cavity or communicates with the reaction cavity through a circulating loop.

[0015] Preferably, the out-of-pile fuel cladding chemical interaction reaction device further comprises an oxygen adsorption unit connected with the reaction cavity.

[0016] Preferably, the oxygen control unit comprises an oxygen sensor and a proportional-integral-derivative controller.

[0017] The out-of-pile fuel cladding chemical interaction reaction device has the following advantages: through the cooperation of the argon supply unit, the oxygen supply unit and the oxygen control unit, the delivery flow of argon-oxygen mixed gas can be controlled, the oxygen content in the reaction cavity can be controlled, the oxygen content in the fuel-cladding gap under different burnups in the reactor can be effectively simulated, and the balance of the oxygen content in the reaction cavity can be avoided from being destroyed by volatile fission products such as Cs. BRIEF DESCRIPTION OF DRAWINGS

[0018] The utility model will be further described below in combination with the drawings and embodiments, wherein:

[0019] Figure 1 is the structure schematic diagram of the out-of-pile fuel cladding chemical interaction reaction device of an embodiment of the utility model. DETAILED DESCRIPTION

[0020] In order to have more clear understanding of the technical features, objects and effects of the utility model, the specific implementation mode of the utility model will be described in detail by referring to the drawings.

[0021] As Figure 1 shown, the out-of-pile fuel cladding chemical interaction reaction device (also can be called out-of-pile FCCI simulation test device) of an embodiment of the utility model includes airtight reaction cavity, argon supply unit, oxygen supply unit and oxygen control unit 80.

[0022] Among them, the reaction cavity is used for placing cladding test piece 100 and corrosive medium and provides reaction environment for both. The argon supply unit is connected with the reaction cavity and the oxygen supply unit respectively and is used for delivering argon to the reaction cavity and the oxygen supply unit respectively. The oxygen supply unit is connected with the reaction cavity and is used for delivering oxygen to the reaction cavity, which is combined with the argon provided by the argon supply unit, and actually delivers the mixed oxygen and argon from the argon supply unit into the reaction cavity. The oxygen control unit 80 is used for detecting the oxygen content in the reaction cavity and controls the start and stop of the oxygen supply unit according to the oxygen content.

[0023] Specifically, the reaction cavity can include high temperature furnace 10, alumina crucible 20 arranged in the high temperature furnace 10 and used for accommodating cladding test piece 100 and corrosive medium (representing the fission product of fuel). In the high temperature furnace 10, the alumina crucible 20 contains corrosive medium, and the cladding test piece 100 is placed in the alumina crucible 20 and immersed in the corrosive medium.

[0024] The temperature in the high temperature furnace 10 can be adjusted, which can simulate the in-pile temperature and provide the reaction temperature of simulated in-pile environment for the cladding test piece 100 and corrosive medium.

[0025] Preferably, the high temperature furnace 10 adopts muffle furnace with good sealing property, so as to keep the constant oxygen content in the furnace and provide high temperature condition for the out-of-pile FCCI test.

[0026] The argon supply unit specifically can include an argon source 30, a first argon pipeline 31 and a second argon pipeline 32; the argon source 30 can be an argon tank or the like container filled with argon. The first argon pipeline 31 is connected between the argon source 30 and the reaction cavity (specifically the high-temperature furnace 10), so that the argon of the argon source 30 is transported into the high-temperature furnace 10 through the first argon pipeline 31. The second argon pipeline 32 is connected between the argon source 30 and the oxygen supply unit, so that the argon of the argon source 30 is transported to the oxygen supply unit through the second argon pipeline 32 to be mixed with oxygen.

[0027] The oxygen supply unit can include an oxygen source 40 and an oxygen pipeline 41 connected between the oxygen source 40 and the reaction cavity (specifically the high-temperature furnace 10). The oxygen source 40 can be an oxygen tank or the like container filled with oxygen, which provides oxygen that can be transported to the high-temperature furnace 10 through the oxygen pipeline 41. The second argon pipeline 32 is connected between the argon source 30 and the oxygen pipeline 41, so that the argon from the argon source 30 is mixed with oxygen in the oxygen pipeline 41 to form argon-oxygen mixed gas before being transported into the high-temperature furnace 10.

[0028] Since the oxygen potential required by the reaction test does not change much, the amount of oxygen filled is very small, and it is difficult to achieve high control accuracy by filling oxygen alone, so argon is filled at the same time to mix with oxygen to dilute the oxygen, thereby achieving relatively high control accuracy. Therefore, in the utility model, the second argon pipeline 32 is connected to the oxygen supply unit to introduce argon into the oxygen supply path to mix with oxygen.

[0029] In order to make the argon and oxygen mix better before entering the high-temperature furnace 10, in some embodiments, the oxygen supply unit further includes a mixing cavity 42 for mixing argon and oxygen to form argon-oxygen mixed gas. The mixing cavity 42 is provided on the oxygen pipeline 41, and correspondingly, the second argon pipeline 32 is connected between the argon source 30 and the mixing cavity 42.

[0030] The oxygen control unit 80 can detect the oxygen content in the high-temperature furnace 10 and compare the oxygen content with the target oxygen content. When the oxygen content in the high-temperature furnace 10 is lower than the target oxygen content, the oxygen control unit 80 controls the oxygen supply unit to transport argon-oxygen mixed gas to the high-temperature furnace 10; when the oxygen content in the high-temperature furnace 10 is higher than the target oxygen content, the oxygen control unit 80 controls the oxygen supply unit to stop transporting argon-oxygen mixed gas.

[0031] The oxygen control unit 80 specifically can include an oxygen sensor and a proportional-integral-derivative (PID) controller, which monitors the oxygen content in the high-temperature furnace 10 in real time, and the proportional-integral-derivative controller controls the start and stop of the oxygen supply unit according to the measured oxygen content, thereby effectively controlling the oxygen content in the high-temperature furnace 10. In summary, the oxygen control unit 80 can monitor the oxygen content in the high-temperature furnace 10 in real time and feedback adjust the delivery flow of the argon-oxygen mixed gas.

[0032] Further, the out-of-pile fuel cladding chemical interaction reaction device can further comprise a vacuum pump 50, the vacuum pump 50 is connected with the reaction cavity (specifically, the high-temperature furnace 10) through a vacuum pipeline 51, and vacuum operation in the high-temperature furnace 10 is realized.

[0033] It can be understood that the above-mentioned various pipelines, including the first argon pipeline 31, the second argon pipeline 32, the oxygen pipeline 41 and the vacuum pipeline 51, are respectively provided with valves for controlling the opening and closing and flow of the pipelines.

[0034] The out-of-pile fuel cladding chemical interaction reaction device can further comprise a circulating fan 60 for driving the circulating flow of the gas in the reaction cavity.

[0035] In the reaction cavity, generally, simple substances such as cesium are added as the fission products of the fuel, and the boiling point of cesium is not high, and generally in a gaseous state at the test temperature, in order to keep the amount of cesium in the reaction device unchanged, the circulating fan 60 is an internal circulating fan.

[0036] Alternatively, the circulating fan 60 can be arranged in the reaction cavity (in the high-temperature furnace 10) or connected with the reaction cavity (the high-temperature furnace 10) through a circulating loop.

[0037] The out-of-pile fuel cladding chemical interaction reaction device can further comprise an oxygen adsorption unit 70; the oxygen adsorption unit 70 is connected with the reaction cavity (the high-temperature furnace 10) and is used for adsorbing oxygen in the high-temperature furnace 10 and reducing the oxygen content. The oxygen adsorption unit 70 comprises an oxygen scavenger, and the oxygen scavenger comprises a copper catalyst or a titanium alloy.

[0038] The oxygen adsorption unit 70 works in cooperation with the circulating fan 60. When the oxygen content in the high-temperature furnace 10 is higher than the target oxygen content, the oxygen control unit 80 controls the oxygen supply unit to stop the delivery of the argon-oxygen mixed gas, and starts the circulating fan 60, and the oxygen in the high-temperature furnace 10 is adsorbed by the oxygen adsorption unit 70. Finally, by setting the heating temperature and the heating time of the high-temperature furnace 10, the out-of-pile FCCI simulation test under different oxygen contents is realized.

[0039] When the out-of-pile fuel cladding chemical interaction reaction device works:

[0040] First, the corrosive medium and the cladding test piece 100 are arranged in the alumina crucible 20 in the high-temperature furnace 10, a vacuum pump 50 is used to pump the high-temperature furnace 10 to reach a high vacuum level, and then the argon gas supply unit is used to deliver argon gas into the high-temperature furnace 10, so that the atmosphere in the high-temperature furnace 10 is filled with high-purity argon gas. Secondly, the target oxygen content is set in the oxygen control unit 80, when the oxygen content in the high-temperature furnace 10 is lower than the target oxygen content, the oxygen control unit 80 controls the oxygen gas supply unit to deliver argon-oxygen mixed gas into the high-temperature furnace 10; when the oxygen content in the high-temperature furnace 10 is higher than the target oxygen content, the oxygen control unit 80 controls the oxygen gas supply unit to stop delivering argon-oxygen mixed gas, and starts the circulating fan 60, and the oxygen in the high-temperature furnace 10 is adsorbed by the oxygen adsorption unit 70. Finally, the heating temperature and the heating time are set through the high-temperature furnace 10, so as to realize the out-of-pile FCCI simulation test under different oxygen contents.

[0041] The above is only an embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, is also included in the patent protection range of the present application.

Claims

1. An out-of-pile fuel clad chemical interaction reaction apparatus characterized by, The reactor includes a reaction chamber for placing a cladding sample and a corrosive medium, an argon supply unit for supplying argon, an oxygen supply unit for supplying oxygen, and an oxygen control unit. The argon supply unit is connected to the reaction chamber and the oxygen supply unit, respectively; the oxygen supply unit is connected to the reaction chamber, and the oxygen mixed with argon from the argon supply unit is delivered into the reaction chamber. The oxygen control unit is used for detecting the oxygen content in the reaction chamber, and controlling the start and stop of the oxygen supply unit according to the oxygen content.

2. The out-of-pile fuel cladding chemical interaction reaction apparatus according to claim 1, characterized by, The reaction chamber includes a high-temperature furnace and an alumina crucible arranged in the high-temperature furnace and used for accommodating the cladding sample and the corrosive medium.

3. The out-of-pile fuel cladding chemical interaction reaction apparatus according to claim 1, characterized by, The argon supply unit includes an argon source, a first argon pipeline connected between the argon source and the reaction chamber, and a second argon pipeline connected between the argon source and the oxygen supply unit.

4. The out-of-pile fuel cladding chemical interaction reaction apparatus according to claim 3, characterized by The oxygen supply unit includes an oxygen source and an oxygen pipeline connected between the oxygen source and the reaction chamber; the second argon pipeline is connected between the argon source and the oxygen pipeline.

5. The out-of-pile fuel cladding chemical interaction reaction apparatus according to claim 4, characterized by The oxygen supply unit further includes a mixing chamber for mixing argon and oxygen to form argon-oxygen mixed gas, and the mixing chamber is arranged on the oxygen pipeline; the second argon pipeline is connected between the argon source and the mixing chamber.

6. The out-of-pile fuel cladding chemical interaction reaction apparatus according to any one of claims 1 to 5, characterized by, The out-of-pile chemical interaction reactor further includes a vacuum pump connected to the reaction chamber through a vacuum pipeline.

7. The out-of-pile fuel cladding chemical interaction reaction apparatus according to any one of claims 1 to 5, characterized by, The out-of-pile chemical interaction reactor further includes a circulating fan for driving the circulation of gas in the reaction chamber.

8. The out-of-pile fuel cladding chemical interaction reaction apparatus according to claim 7, characterized by The circulating fan is arranged in the reaction chamber, or is connected to the reaction chamber through a circulating loop.

9. The out-of-pile fuel cladding chemical interaction reaction apparatus according to any one of claims 1 to 5, characterized by, The out-of-pile chemical interaction reactor further includes an oxygen adsorption unit connected to the reaction chamber.

10. The out-of-pile fuel cladding chemical interaction reaction apparatus according to any one of claims 1 to 5, characterized by, The oxygen control unit includes an oxygen sensor and a proportional-integral-derivative controller.

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