Method for preventing hydrogen release safety problem

Abstract

The invention discloses a method for preventing a hydrogen release safety problem. The method comprises the following steps: determining storage feed liquid in equipment; calculating the hydrogen release amount Q of the storage material liquid in the equipment; according to the hydrogen release amount Q of the storage material liquid, the time t for the hydrogen to reach the preset volume proportion where the hydrogen safely exists in the free space of the equipment is calculated, and the volume V of the free space of the equipment is obtained by subtracting the preset maximum charging volume from the equipment volume; and when the preset safety processing time t0 is greater than the time t when the hydrogen reaches the preset hydrogen safety existing volume ratio, performing prevention measures for preventing the hydrogen release safety problem. During equipment design, the hydrogen release amount is reasonably calculated, proper safety allowance is reserved, reasonable classification is performed according to different hydrogen release amounts, by means of air purging hydrogen, hydrogen concentration monitoring and the like, it is avoided that due to accumulation of hydrogen concentration, safe operation of a factory is affected, and safety, reliability and economical efficiency are comprehensively considered.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear fuel reprocessing, and particularly relates to a method for preventing hydrogen release safety problems. Background Art

[0002] The main processing objects of a nuclear fuel reprocessing plant are uranium, plutonium, and fission products generated by irradiation, which are radioactive. Substances containing hydrogen elements such as water in the process system will generate hydrogen when irradiated. The explosion limit of hydrogen is 4.0 - 75.6% (volume fraction), that is, when hydrogen is mixed with air, if the proportion of hydrogen is within the explosion limit, it will explode when encountering fire. Hydrogen explosion is a very serious safety accident in the reprocessing plant. Certain measures should be taken during the design process to avoid hydrogen explosion in the reprocessing plant. At the same time, considering the process and equipment to be simple and convenient, with a certain economy, and avoiding adding too many redundant devices. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for preventing hydrogen release safety problems in view of the above deficiencies in the prior art. For the equipment in the PUREX process of spent fuel reprocessing, the equipment limitation conditions considering hydrogen release problems are proposed, a reasonable calculation method for hydrogen release amount is given, and reasonable classification is carried out according to the size of the hydrogen release amount, and a method and system for preventing hydrogen release safety problems are given.

[0004] The technical solution adopted to solve the technical problem of the present invention is to provide a method for preventing hydrogen release safety problems, including the following steps:

[0005] (1) Determine the stored feed liquid in the equipment of the reprocessing plant;

[0006] (2) Calculate the hydrogen release amount Q of the stored feed liquid in the equipment;

[0007] (3) According to the hydrogen release amount Q of the stored feed liquid, calculate the time t when hydrogen reaches the volume ratio of the preset safe hydrogen existence in the free space of the equipment. The free space volume V of the equipment is the equipment volume minus the maximum volume of the preset feeding;

[0008] (4) When the preset safe processing time t0 of the reprocessing plant is greater than the time t when hydrogen reaches the volume ratio of the preset safe hydrogen existence, preventive measures for preventing hydrogen release safety problems are taken.

[0009] Preferably, in the step (1), the stored feed liquid in the equipment of the reprocessing plant includes plutonium-containing solution and / or other radioactive solutions.

[0010] Preferably, in the step (1), the plutonium content in the plutonium-containing solution is not less than 5 g / L, and the β / γ radioactivity of other radioactive solutions is not less than 1×10 9 Bq / L.

[0011] Preferably, in the step (2), the calculation method for the hydrogen release amount Q of the stored liquid in the computing device is to calculate the hydrogen release amounts of the hydrogen generated by α-radiolysis and the hydrogen generated by β, γ-radiolysis respectively, and then sum them up.

[0012] Preferably, in the step (2), the hydrogen release amount of the hydrogen generated by α-radiolysis is determined by calculating the nitric acid concentration of the stored liquid, the α-radiation power of the stored liquid, and the number of hydrogen molecules generated per unit energy.

[0013] Preferably, in the step (2), the hydrogen release amounts of the hydrogen generated by β, γ-radiolysis are determined by calculating the β, γ-radiation powers of the stored liquid and the number of hydrogen molecules generated per unit energy.

[0014] Preferably, in the step (3), the calculation method for the time t when the hydrogen reaches the preset volume ratio for safe hydrogen existence is as follows:

[0015] t = V×σ / Q, where V is the free space of the device, σ is the volume ratio when the hydrogen reaches the preset volume ratio for safe hydrogen existence, and Q is the hydrogen release amount of the stored liquid in the device.

[0016] Preferably, in the step (3), the free space volume V of the device is 5 - 50% of the device volume.

[0017] Preferably, in the step (3), the volume ratio σ when the hydrogen reaches the preset volume ratio for safe hydrogen existence is not greater than 4%.

[0018] Preferably, in the step (3), the volume ratio σ when the hydrogen reaches the preset volume ratio for safe hydrogen existence is 0.5% - 3%.

[0019] Preferably, in the step (3), the time t when the hydrogen reaches the preset volume ratio for safe hydrogen existence is determined according to the comprehensive management means of the factory.

[0020] Preferably, in the step (4), the preset safety treatment time t0 of the reprocessing plant is 30 - 800 h.

[0021] Preferably, the preventive measures in the step (4) include:

[0022] When the hydrogen concentration reaches the preset value, air is introduced into the device to dilute the hydrogen, or air is introduced into the device for continuous purging, or an alarm is given.

[0023] Preferably, the preventive measures in the step (4) include:

[0024] When the hydrogen concentration reaches the preset value, air is introduced into the device for continuous purging, and an alarm is given.

[0025] The beneficial effects of the method for preventing hydrogen release safety problems in the present invention are as follows:

[0026] (1) Prevent hydrogen release safety problems in the reprocessing plant, and avoid personal injuries, environmental damages, and economic losses caused by hydrogen explosions in the reprocessing plant;

[0027] (2) Accurately calculate the hydrogen release amount according to the material characteristics, and effectively and reasonably distinguish whether it is necessary to add devices and measures for preventing hydrogen release problems;

[0028] (3) Reasonably set up devices for preventing hydrogen release problems according to the calculated hydrogen release amount and process environment, which are safe, reliable, and highly economical. Specific Embodiments

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with specific embodiments.

[0030] Embodiment 1

[0031] This embodiment provides a method for preventing hydrogen release safety problems, including the following steps:

[0032] (1) Determine the stored liquid in the equipment of the reprocessing plant;

[0033] (2) Calculate the hydrogen release amount Q of the stored liquid in the equipment;

[0034] (3) According to the hydrogen release amount Q of the stored liquid, calculate the time t when the hydrogen reaches the volume ratio of the preset safe hydrogen existence in the free space of the equipment. The free space volume V of the equipment is the equipment volume minus the maximum volume of the preset feeding;

[0035] (4) When the preset safety treatment time t0 of the reprocessing plant is greater than the time t when the hydrogen reaches the volume ratio of the preset safe hydrogen existence, preventive measures for preventing hydrogen release safety problems are taken.

[0036] The beneficial effects of the method for preventing hydrogen release safety problems in this embodiment are as follows:

[0037] (1) Prevent hydrogen release safety problems in the reprocessing plant, and avoid personal injuries, environmental damages, and economic losses caused by hydrogen explosions in the reprocessing plant;

[0038] (2) Accurately calculate the hydrogen release amount according to the material characteristics, and effectively and reasonably distinguish whether it is necessary to add devices and measures for preventing hydrogen release problems;

[0039] (3) Reasonably set up devices for preventing hydrogen release problems according to the calculated hydrogen release amount and process environment, which are safe, reliable, and highly economical.

[0040] Embodiment 2

[0041] This embodiment provides a method for preventing hydrogen release safety problems, including the following steps:

[0042] (1) Determine the stored feed solution in the equipment of the reprocessing plant;

[0043] (2) Calculate the hydrogen release amount Q of the stored feed solution in the equipment;

[0044] (3) According to the hydrogen release amount Q of the stored feed solution, calculate the time t when the hydrogen reaches the volume ratio of the preset hydrogen safety existence in the free space of the equipment. The free space volume V of the equipment is the equipment volume minus the maximum volume of the preset feed;

[0045] (4) When the preset safety treatment time t0 of the reprocessing plant is greater than the time t when the hydrogen reaches the volume ratio of the preset hydrogen safety existence, preventive measures for preventing hydrogen release safety problems are taken.

[0046] The technical solution of this embodiment is as follows: The equipment limitation conditions considering hydrogen release problems, the hydrogen release amount calculation method, the classification of hydrogen release amounts, the method and system for preventing hydrogen release safety problems need to be considered.

[0047] Preferably, in the step (1), the stored feed solution in the equipment of the reprocessing plant includes plutonium-containing solution and / or other radioactive solutions.

[0048] Preferably, in the step (1), the plutonium content in the plutonium-containing solution is not less than 5 g / L, and the β / γ radioactivity of other radioactive solutions is not less than 1×10 9 Bq / L.

[0049] The equipment limitation conditions considering hydrogen release problems can be classified into plutonium-containing solution and / or other radioactive solutions according to the components of the stored feed solution in the equipment. Equipment that does not belong to any of the above cases of plutonium-containing solution and / or other radioactive solutions generally does not need to consider hydrogen release problems.

[0050] Preferably, in the step (2), the calculation method for calculating the hydrogen release amount Q of the stored feed solution in the equipment is achieved by separately calculating the hydrogen release amount of α-radiolysis hydrogen and the hydrogen release amount of β / γ-radiolysis hydrogen and adding them up. The hydrogen release amount can be expressed as hydrogen gas volume / time, that is, it represents the hydrogen gas volume generated per unit time. Specifically, the hydrogen release amount of α-radiolysis hydrogen is the volume of α-radiolysis hydrogen divided by the radiolysis time of α-radiolysis hydrogen, and the hydrogen release amount of β / γ-radiolysis hydrogen is the volume of β / γ-radiolysis hydrogen divided by the radiolysis time of β / γ-radiolysis hydrogen.

[0051] Preferably, in the step (2), the hydrogen release amount of α-radiolysis hydrogen is determined by calculating the nitric acid concentration of the stored feed solution, the α-radiation power of the stored feed solution, and the number of hydrogen molecules generated per unit energy.

[0052] The hydrogen generated by α radiolysis is related to the nitric acid concentration of the stored liquid, the α radiation power of the stored liquid, and the number of hydrogen molecules generated per unit energy. The α radiation power is related to the constituent elements of the material.

[0053] Preferably, in the step (2), by calculating the β and γ radiation powers of the stored liquid and the number of hydrogen molecules generated per unit energy, the hydrogen release amount of hydrogen generated by β and γ radiolysis is determined.

[0054] The hydrogen generated by β and γ radiolysis is related to the β and γ radiation powers of the stored liquid and the number of hydrogen molecules generated per unit energy. Depending on the composition of the stored liquid, generally 0.01 - 2 hydrogen molecules can be generated per 100 eV of energy.

[0055] Preferably, in the step (3), the calculation method of the time t when hydrogen reaches the preset volume ratio for safe hydrogen storage is as follows:

[0056] t = V×σ / Q, where V is the free space of the equipment, σ is the volume ratio of hydrogen reaching the preset volume ratio for safe hydrogen storage (i.e., the allowable volume ratio of hydrogen), and Q is the hydrogen release amount of the stored liquid in the equipment. Specifically, V is the free space of the storage tank of the equipment.

[0057] The reasonable classification of the hydrogen release amount needs to comprehensively consider the hydrogen release amount of the stored liquid, the free space of the storage tank of the equipment, and the allowable volume ratio of hydrogen (i.e., the volume ratio of hydrogen reaching the preset volume ratio for safe hydrogen storage). Taking the time t when hydrogen reaches the allowable volume ratio of hydrogen (i.e., the time when hydrogen reaches the preset volume ratio for safe hydrogen storage) as the classification basis.

[0058] Preferably, in the step (3), the free space volume V of the equipment is 5 - 50% of the equipment volume.

[0059] Specifically, in this embodiment, the free space V of the storage tank of the equipment needs to be comprehensively combined with the design of the storage tank of the equipment. This volume is calculated by subtracting the maximum preset feeding volume (i.e., the maximum allowable feeding volume) from the storage tank volume, and is generally 5 - 50% of the storage tank volume.

[0060] Preferably, in the step (3), the volume ratio σ of hydrogen reaching the preset volume ratio for safe hydrogen storage is not greater than 4%.

[0061] Preferably, in the step (3), the volume ratio σ of hydrogen reaching the preset volume ratio for safe hydrogen storage is 0.5% - 3%.

[0062] Preferably, in the step (3), the time t when hydrogen reaches the preset volume ratio for safe hydrogen storage is determined according to the comprehensive management means of the factory.

[0063] Preferably, in the step (4), the preset safety treatment time t0 of the reprocessing plant is 30 - 800 h.

[0064] Rational classification basis for the amount of hydrogen released - When setting the time t for hydrogen to reach the preset volume ratio of safe hydrogen existence (the time for hydrogen to reach the allowable volume ratio of hydrogen existence), the management means of the factory should be comprehensively considered, that is, the time when early warning occurs and personnel can handle it in time, generally between 30 and 800 h, which is called t0.

[0065] Since there are situations such as material transportation and free exhaust between the storage tanks of the equipment, where hydrogen can be released along with other gases, when t > t0, there is no need to take preventive measures for hydrogen release safety problems, and there is no need for a device to prevent hydrogen release problems in the equipment. It is only necessary to determine that t > t0 through calculation.

[0066] When t < t0, a device for preventing hydrogen release safety problems needs to be set up, generally including one or several measures such as air dilution, continuous air purge, hydrogen concentration monitoring, hydrogen concentration alarm / interlock, etc.

[0067] Preferably, the preventive measures in step (4) include:

[0068] When the hydrogen concentration reaches the preset value, introduce air into the equipment to dilute hydrogen, or introduce air into the equipment for continuous purge, or give an alarm.

[0069] Preferably, the preventive measures in step (4) include:

[0070] When the hydrogen concentration reaches the preset value, introduce air into the equipment for continuous purge and give an alarm.

[0071] Specifically, air dilution means introducing air into the equipment to reduce the hydrogen concentration in the equipment, and it needs to be used in combination with other measures.

[0072] Specifically, continuous air purge means continuously introducing air into the equipment so that the hydrogen concentration in the equipment never reaches the preset volume ratio of safe hydrogen existence (allowable volume ratio of hydrogen existence) σ. Generally, the air flow rate blown in should be 50 - 300 times the hydrogen release amount Q. Adopt reasonable means to ensure the reliability of continuous air purge, such as using safety-class and earthquake-resistant valves and pipelines.

[0073] Specifically, the monitoring of hydrogen concentration, i.e., monitoring the hydrogen concentration inside the monitoring equipment, needs to be used in conjunction with other measures. The first is to cooperate with air dilution and hydrogen concentration interlock. When the hydrogen concentration is about to reach the preset volume ratio of safe hydrogen existence (the volume ratio allowing hydrogen existence) σ, the equipment is interlocked to introduce air to dilute the hydrogen. At this time, to ensure safety, measures should be taken to ensure the safety of the above devices, such as using safety-class and earthquake-resistant air dilution pipelines and valves, and using safety-class hydrogen concentration monitoring devices. The second is to cooperate with continuous air purge. That is, while continuously purging with air, monitor the hydrogen concentration. When the hydrogen concentration is about to reach the preset volume ratio of safe hydrogen existence (the volume ratio allowing hydrogen existence) σ, an alarm is given. Since there is continuous air purge, the hydrogen concentration monitoring device can be non-safety-class.

[0074] Generally, for equipment with the above continuous air purge set, the equipment can be ensured safe without setting hydrogen concentration monitoring. However, for equipment with a large hydrogen release amount and a very small t, hydrogen concentration monitoring can be set simultaneously to ensure safety.

[0075] The method for preventing hydrogen release safety problems in this embodiment reasonably calculates the hydrogen release amount during equipment design, reserves an appropriate safety margin, classifies reasonably according to different hydrogen release amounts, and avoids affecting the safe operation of the reprocessing plant due to the accumulation of hydrogen concentration by means of setting air purge for hydrogen and hydrogen concentration monitoring, etc., comprehensively considering safety, reliability and economy.

[0076] Specifically, in this embodiment, it is assumed that the material is a radioactive solution with a radioactivity of 2×10 9 Bq / L. Initially judged, it is necessary to calculate the hydrogen release amount.

[0077] Through calculation, assuming that the hydrogen amount released by α radiolysis is 0.001 L / h and the hydrogen amount released by β and γ radiation is 0.01 L / h, then the hydrogen release amount Q is 0.011 standard L / h.

[0078] Assume that the equipment volume is 2000 L and the free space V is 700 L.

[0079] The volume ratio σ allowing hydrogen existence is taken as 1%.

[0080] t0 is in the range of 30 - 800 h, and 100 h is taken.

[0081] At this time, when the time t for hydrogen to reach the volume ratio of allowed hydrogen existence = free space V × volume ratio σ of allowed hydrogen existence / hydrogen release amount Q = 700 (L) × 1% / 0.011 (L / h) = 636 h.

[0082] Since t > t0, there is no need to set measures for preventing hydrogen release safety problems.

[0083] The beneficial effects of the method for preventing hydrogen release safety problems in this embodiment are as follows:

[0084] (1) Prevent hydrogen release safety problems in the reprocessing plant, and avoid personal injuries, environmental damages and economic losses caused by hydrogen explosion in the reprocessing plant;

[0085] (2) Accurately calculate the hydrogen release amount according to the material characteristics, and effectively and reasonably distinguish whether it is necessary to add devices and measures for preventing hydrogen release problems;

[0086] (3) Reasonably set devices for preventing hydrogen release problems according to the calculated hydrogen release amount and process environment, which are safe, reliable and highly economical.

[0087] Example 3

[0088] This embodiment provides a method for preventing hydrogen release safety problems, including the following steps. The difference from Example 2 is:

[0089] Assume that the material contains plutonium with a plutonium concentration of 10 g / L. Initially judge that it is necessary to calculate the hydrogen release amount.

[0090] Through calculation, assume that the hydrogen amount released by its α radiolysis is 5 L / h, and assume that the hydrogen amount released by its β and γ radiations is 0.1 L / h. Then the hydrogen release amount Q is 5.1 standard L / h.

[0091] Assume that the equipment volume is 3000 L and the free space V is 1000 L.

[0092] The volume ratio σ of allowable hydrogen presence is taken as 2%.

[0093] t0 is between 30 and 800 h, and 200 h is taken.

[0094] At this time, when the time t for hydrogen to reach the volume ratio of allowable hydrogen presence = free space V × volume ratio σ of allowable hydrogen presence / hydrogen release amount Q = 1000 (L) × 2% / 5.1 (L / h) = 3.92 h.

[0095] Since t < t0, it is necessary to set means for preventing hydrogen release safety problems.

[0096] Set a safety-class and earthquake-resistant continuous air purge, and the air flow rate is taken as 150 times the hydrogen release amount Q, that is, 765 standard L / h.

[0097] The beneficial effects of the method for preventing hydrogen release safety problems in this embodiment are as follows:

[0098] (1) Prevent hydrogen release safety problems in the reprocessing plant, and avoid personal injuries, environmental damages and economic losses caused by hydrogen explosion in the reprocessing plant;

[0099] (2) Calculate the hydrogen release amount accurately according to the material characteristics, and effectively and reasonably distinguish whether it is necessary to add devices and measures to prevent hydrogen release problems;

[0100] (3) Set up devices to prevent hydrogen release problems reasonably according to the calculated hydrogen release amount and the process environment, which are safe, reliable and highly economical.

[0101] Example 4

[0102] This example provides a method for preventing hydrogen release safety problems, including the following steps. The difference from Example 2 is:

[0103] Assume that the material contains plutonium with a plutonium concentration of 50 g / L. Initially judge that it is necessary to calculate the hydrogen release amount.

[0104] Through calculation, assume that the hydrogen amount released by its α radiolysis is 20 L / h, and assume that the hydrogen amounts released by its β and γ radiations are 0.1 L / h. Then the hydrogen release amount Q is 20.1 standard L / h.

[0105] Assume that the equipment volume is 800 L and the free space V is 100 L.

[0106] The volume ratio σ of hydrogen allowed to exist is taken as 2%.

[0107] t0 is in the range of 30 - 800 h, and take 72 h.

[0108] At this time, when the time t for hydrogen to reach the volume ratio of hydrogen allowed to exist is t = free space V × volume ratio σ of hydrogen allowed to exist / hydrogen release amount Q = 100 (L) × 2% / 20.1 (L / h) = 0.1 h.

[0109] Since t < t0, it is necessary to set means to prevent hydrogen release safety problems.

[0110] Set up a safety-class and earthquake-resistant continuous air purge, and the air flow rate is taken as 200 times of the hydrogen release amount Q, that is, 4020 standard L / h.

[0111] Since the hydrogen release amount Q is large and t is very small, only 0.1 h, so set up a safety-class hydrogen concentration monitoring and alarm when approaching 0.1 h. The dual devices ensure safety.

[0112] The beneficial effects of the method for preventing hydrogen release safety problems in this example are as follows:

[0113] (1) Prevent hydrogen release safety problems in the reprocessing plant, and avoid personal injuries, environmental damages and economic losses caused by hydrogen explosion in the reprocessing plant;

[0114] (2) Calculate the hydrogen release amount accurately according to the material characteristics, and effectively and reasonably distinguish whether it is necessary to add devices and measures to prevent hydrogen release problems;

[0115] (3) Reasonably set up devices for preventing hydrogen release problems according to the calculated hydrogen release amount and process environment, which are safe, reliable and highly economical.

[0116] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill 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 regarded as the protection scope of the present invention.

Claims

1. A method for preventing hydrogen release safety issues, characterized in that: The following steps are involved: (1) Determine the storage liquid in the equipment of the post-processing plant; (2) Calculate the amount of hydrogen released from the stored liquid in the equipment, Q; (3) Based on the amount of hydrogen released Q by the stored liquid, calculate the time t for the hydrogen to reach the preset volume ratio for safe existence of hydrogen in the free space of the equipment. The free space volume V of the equipment is the equipment volume minus the preset maximum volume of the added material; (4) When the safe processing time t0 preset by the post-processing plant is greater than the time t for hydrogen to reach the preset volume ratio for safe existence of hydrogen, preventive measures are taken to prevent safety issues of hydrogen release.

2. The method for preventing hydrogen release safety issues according to claim 1, characterized in that: In the step (1), the stored liquid in the equipment of the post-processing plant includes a plutonium-containing solution and / or other radioactive solutions.

3. The method for preventing hydrogen release safety issues according to claim 2, characterized in that: In the step (1), the plutonium content in the plutonium-containing solution is not less than 5 g / L, and the β / γ radioactivity of other radioactive solutions is not less than 1×10 9 Bq / L.

4. The method for preventing hydrogen release safety issues according to claim 1, characterized in that: In the step (2), the method for calculating the amount of hydrogen released Q of the stored liquid in the calculation device is to calculate the amount of hydrogen released by α-radiolysis and the amount of hydrogen released by β- and γ-radiolysis respectively and add them up.

5. The method for preventing hydrogen release safety issues according to claim 4, characterized in that: In the step (2), the amount of hydrogen released by α-radiolysis is determined by calculating the nitric acid concentration of the stored solution, the α-radiation power of the stored solution, and the number of hydrogen molecules generated per unit energy.

6. The method for preventing hydrogen release safety issues according to claim 4, characterized in that: In the step (2), the amount of hydrogen released by β- and γ-radiolysis is determined by calculating the β- and γ-radiation power of the stored liquid and the number of hydrogen molecules generated per unit energy.

7. The method for preventing hydrogen release safety issues according to claim 1, characterized in that: The calculation method of the time t for the hydrogen to reach the preset volume ratio for safe existence of hydrogen in step (3) is as follows: t=V×σ / Q, where V is the free space of the equipment, σ is the volume ratio of hydrogen reaching the preset safe existence of hydrogen, and Q is the amount of hydrogen released from the stored liquid in the equipment.

8. The method for preventing safety issues of hydrogen release according to claim 1 or 7, characterized in that: The free space volume V of the equipment in step (3) is 5 to 50% of the equipment volume.

9. The method for preventing safety issues of hydrogen release according to claim 7, characterized in that: In the step (3), the volume proportion σ of hydrogen reaching the preset safe existence of hydrogen is no more than 4%.

10. The method for preventing safety issues of hydrogen release according to claim 9, characterized in that: In the step (3), the volume proportion σ of hydrogen reaching the preset safe existence of hydrogen is 0.5% to 3%.

11. The method for preventing hydrogen release safety issues according to claim 1, characterized in that: In the step (3), the time t at which the hydrogen reaches the preset volume proportion for safe existence of hydrogen is determined according to comprehensive factory management measures.

12. The method for preventing safety issues of hydrogen release according to claim 1, characterized in that: In step (4), the post-processing plant presets a safe processing time t0 of 30 to 800 hours.

13. The method for preventing hydrogen release safety issues according to claim 1, characterized in that: The preventive measures in step (4) include: When the hydrogen concentration reaches the preset value, air is introduced into the equipment to dilute the hydrogen, or air is introduced into the equipment for continuous purge, or an alarm is sounded.

14. The method for preventing safety issues of hydrogen release according to claim 1, characterized in that: The preventive measures in step (4) include: When the hydrogen concentration reaches the preset value, air is introduced into the equipment for continuous purge and an alarm is sounded.