Method for treating radioactive activated carbon in nuclear power station

Abstract

The invention discloses a radioactive activated carbon treatment method for a nuclear power station. The radioactive activated carbon treatment method comprises the following steps: S1, shielding and storing waste activated carbon replaced by an iodine filter; s2, carrying out representative sampling and sample preparation on the waste activated carbon; s3, detecting and analyzing the nuclide activity concentration of the sample; s4, carrying out conformity evaluation on an analysis result and a control release limit value; and S5, dividing the waste activated carbon into hazardous wastes or radioactive wastes according to the evaluation result and the decontrol standard, and performing corresponding treatment. Through scientific sampling and rigorous evaluation, the problem that the treatment cost is high when the waste activated carbon in the nuclear power station is completely used as radioactive waste is solved, on the premise that nuclear safety is ensured, accurate diversion and low-cost compliance treatment of the waste are achieved, and remarkable safety, economical efficiency and environment friendliness are achieved.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste treatment, and more specifically, to a method for treating radioactive activated carbon from nuclear power plants. Background Technology

[0002] During the operation of nuclear power plants, the iodine filters in the ventilation system generate large amounts of radioactive activated carbon with varying activity concentrations. Current technologies for treating radioactive activated carbon are relatively limited, mostly employing conventional methods such as incineration, solidification, and landfill. These methods present several problems: firstly, they are costly, imposing a heavy economic burden on nuclear power plant operations; secondly, they are not environmentally friendly, placing significant pressure on the environment. Therefore, there is an urgent need to develop an economically and environmentally friendly method for treating radioactive activated carbon. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an environmentally friendly, safe, economical and easy-to-operate method for treating radioactive activated carbon in nuclear power plants.

[0004] The technical solution adopted by this invention to solve its technical problem is: providing a method for treating radioactive activated carbon in nuclear power plants, applied to waste activated carbon in the ventilation system of a nuclear power plant, wherein the ventilation system includes an iodine filter, and the method includes the following steps:

[0005] S1. Shield and store the waste activated carbon after replacing the iodine filter;

[0006] S2. Take representative samples and prepare samples of the waste activated carbon;

[0007] S3. Detect and analyze the activity concentration of the sample nuclides;

[0008] S4. Conduct a compliance assessment of the analysis results with the control limits;

[0009] S5. Based on the assessment results and de-control standards, the waste activated carbon will be diverted into hazardous waste or radioactive waste and disposed of accordingly.

[0010] Furthermore, in step S1, the waste activated carbon removed from the iodine filter is temporarily stored in a radiation shielding box.

[0011] Further, in step S2, the representative sampling of the waste activated carbon includes the following steps:

[0012] S31. Determine the sampling dimensions and divide the waste activated carbon temporary storage shielding box into a three-dimensional grid along the X-axis, Y-axis, and Z-axis;

[0013] S32. Set up sampling points. Set up 1-5 sampling layers on the XY plane in the three-dimensional grid, and set up 1-8 sampling points in each sampling layer in the Z-axis direction.

[0014] S33. Sub-sample collection: Using a special sampler for waste activated carbon, a columnar activated carbon core penetrating the XY plane where the sampling point is located is drilled out as a sub-sample.

[0015] Furthermore, in step S2, the representative sample preparation of the waste activated carbon involves crushing, mixing, and thoroughly stirring the columnar activated carbon core obtained from drilling, and then collecting the sample using a multi-dimensional sampling method to finally obtain the analytical sample.

[0016] Furthermore, in step S3, the detection and analysis of the sample nuclide activity concentration is performed using gamma spectroscopy and / or liquid scintillation counting.

[0017] Further, in step S3, the detection and analysis of the sample nuclide activity concentration includes... 3 H, 14 C 60 Co、 58 Co、 137 Cs、 134 Cs、 95 Zr、 95 Nb, 54 Mn, 59 Fe、 125 Sb、 124 Sb、 110m At least one of Ag.

[0018] Furthermore, in step S4, the conformity assessment of the analysis results and the control limit includes the sample representativeness assessment and the control limit assessment.

[0019] Furthermore, to ensure that the radionuclide activity concentration levels of the collected samples are representative of the overall batch of waste activated carbon radionuclide activity concentration levels, a representativeness assessment of the samples is conducted. The number of samples collected should reach the minimum number of samples n required to achieve the confidence level (95%) calculated according to formula (1):

[0020]

[0021] In the formula, s: the standard deviation of the sample;

[0022] n: Number of samples;

[0023] The average value of the measured quantities of n samples;

[0024] If the number of samples collected is greater than or equal to the minimum number of samples calculated, then the control limit for this batch of waste activated carbon should be assessed to determine whether the control should be lifted.

[0025] If the number of samples collected is less than the minimum number of samples calculated, additional samples need to be collected until the number of samples collected is greater than or equal to the minimum number of samples calculated by formula (1).

[0026] Furthermore, the decontrol limit assessment includes decontrol limit assessment for a single nuclide and / or decontrol limit assessment for a mixture of multiple nuclides;

[0027] The assessment of the delimitation limit for a single nuclide is based on the standard deviation of the sample mean calculated according to formula (2). Combined with sample average calculate like If the calculated value is lower than the limit of the release standard, it means that the release standard is met with a 95% confidence level. Formula (2) is as follows:

[0028]

[0029] In the formula, s: the standard deviation of the sample;

[0030] n: Number of samples;

[0031] Standard deviation of the sample mean;

[0032] For the assessment of the deregulation limits of the mixture of multiple nuclides, the sum of the ratios of the activity concentration of each radionuclide to its upper limit of activity concentration in the deregulation standard should satisfy formula (3):

[0033]

[0034] In the formula, C i : Activity concentration of the i-th artificial radionuclide in the material, Bq / g;

[0035] C oi : The upper limit of the activity concentration of the i-th artificial radionuclide in the de-control standard, Bq / g;

[0036] n: The number of artificial radionuclides present in the material, dimensionless.

[0037] Further, in step S5, the corresponding processing is as follows:

[0038] If the assessment results meet the release criteria, the waste activated carbon will be packaged and transferred to a hazardous waste treatment facility for disposal as hazardous waste.

[0039] If the assessment results do not meet the de-control criteria, the waste activated carbon will be packaged and transferred to a radioactive waste treatment facility for disposal as radioactive solid waste.

[0040] The method for treating radioactive activated carbon in nuclear power plants according to the present invention has the following beneficial effects: Through scientific sampling and rigorous evaluation, the waste activated carbon in nuclear power plants is diverted into hazardous waste or radioactive waste, which greatly reduces the mass of waste activated carbon in nuclear power plants that needs to be treated as radioactive waste. This solves the problem of high costs associated with the complete disposal of waste activated carbon in nuclear power plants as radioactive waste. It achieves accurate diversion and low-cost compliant disposal of waste while ensuring nuclear safety, and has significant safety, economic and environmental benefits. Attached Figure Description

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0042] Figure 1 This is an overall flow chart of the nuclear power plant radioactive activated carbon treatment method of the present invention;

[0043] Figure 2 This is a schematic diagram of the three-dimensional mesh sampling of the shielding box of the present invention;

[0044] Figure 3 This is a flowchart of the evaluation process for the conformity between the analysis results and the control limits of this invention. Detailed Implementation

[0045] Embodiments of the present invention will now be described in more detail. It should be understood that those skilled in the art can implement the invention in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the invention more thorough and complete, and to fully convey the scope of the invention to those skilled in the art.

[0046] One embodiment of this application provides a method for treating radioactive activated carbon in a nuclear power plant, such as... Figures 1-3 As shown, it includes the following steps:

[0047] S1. Shield and store the spent activated carbon removed from the iodine filter. This step serves two purposes: firstly, to prevent radiation leakage from the spent activated carbon removed from the iodine filter in the ventilation system, which could endanger the health and lives of workers; secondly, to centrally manage the removed spent activated carbon for subsequent sampling, testing, and disposal.

[0048] Furthermore, the waste activated carbon from the iodine filter replacement is temporarily stored in a radiation-shielded box. The outer surface material of the radiation-shielded box includes, but is not limited to, lead, steel, aluminum, tungsten, titanium, tantalum, boron, concrete, graphite, boron aluminum carbide, polyethylene, boron-containing polyethylene, and plexiglass. Using these materials effectively attenuates radiation intensity, reducing the radiation dose rate on the outer surface of the box to the lowest possible level, thus protecting the health and safety of personnel. In addition, the shielding box, as a regular geometric shape, provides a systematic and representative grid layout for subsequent three-dimensional mesh generation and sampling, a crucial prerequisite for the accuracy and representativeness of subsequent test results. The specific shape can be a polyhedron or a prism with curved sides, such as a prism, cylinder, or elliptical cylinder.

[0049] S2. Representative sampling and sample preparation of the waste activated carbon. In step S2, the representative sampling of the waste activated carbon includes the following steps:

[0050] S31. Determine the sampling dimensions and divide the waste activated carbon temporary storage shielding box into a three-dimensional grid along the X-axis, Y-axis, and Z-axis;

[0051] S32. Set up sampling points. Set up 1-5 sampling layers on the XY plane in the three-dimensional grid, and set up 1-8 sampling points in each sampling layer in the Z-axis direction.

[0052] S33. Sub-sample collection: Using a special sampler for waste activated carbon, a columnar activated carbon core penetrating the XY plane where the sampling point is located is drilled out as a sub-sample.

[0053] The number of sampling layers arranged on the XY plane of the three-dimensional grid is 1, 2, 3, 4, or 5, with no specific limitation. The number of sampling points arranged along the Z-axis of each sampling layer is 1, 2, 3, 4, 5, 6, 7, or 8, with no specific limitation. Preferably, the number of sampling layers on the XY plane is 3-5, and the number of sampling points along the Z-axis is 4-8. The optimal range for the number of sampling layers and sampling points ensures that the samples are more representative of the overall quality of the batch of waste activated carbon, effectively avoiding the negative impact of unreliable analytical results due to sampling bias.

[0054] like Figure 2As shown, in this invention, the regularly shaped waste activated carbon temporary storage shielding box is divided into a three-dimensional grid along the X, Y, and Z axes. This effectively ensures that sampling points are comprehensively and uniformly distributed throughout the entire temporary storage shielding box, avoiding local sampling deviations caused by uneven sampling point distribution, and ensuring that the collected samples accurately represent the radioactivity level of the entire batch of waste activated carbon. One to five sampling layers are arranged on the XY plane of the three-dimensional grid, with 1 to 8 sampling points arranged in each sampling layer along the Z-axis. By increasing the number and distribution density of sampling points, result deviations caused by local anomalies are also reduced, improving the representativeness of the samples. A dedicated waste activated carbon sampler is used for drilling and sampling. A columnar activated carbon core penetrating the XY plane where the sampling points are located is drilled as a sub-sample. Using a dedicated sampler for penetrating the plane ensures consistent sampling volume for each sub-sample, reducing errors during the sampling process and improving the accuracy of subsequent result analysis.

[0055] Furthermore, in step S2, the drilled columnar activated carbon core is crushed, mixed, and thoroughly stirred. A multi-dimensional sampling method is then used to collect the sample for analysis. This process serves two purposes: firstly, subsequent radionuclide activity concentration analysis experiments require specific particle size, necessitating sample pretreatment to reduce the particle size to meet the requirements of the detection equipment; secondly, crushing the activated carbon into smaller particles and thoroughly stirring ensures the representativeness of the sample. This dual-sample representativeness sampling mechanism allows the sample to more accurately reflect the radioactivity level of the entire batch of waste activated carbon.

[0056] S3. Detect and analyze the activity concentration of the sample nuclides;

[0057] Furthermore, gamma spectroscopy and / or liquid scintillation counting are used to detect and analyze the nuclide activity concentration in the samples. Specifically, representative samples collected in the above steps are sent to a third-party testing unit for nuclide activity concentration detection and analysis. In the nuclide activity concentration detection of this application, gamma spectroscopy and / or liquid scintillation counting are used. Gamma spectroscopy is a highly sensitive and high-resolution detection method capable of accurately measuring the activity concentration of multiple radionuclides in a sample. It is suitable for the detection of multiple nuclides, and by analyzing the energy spectrum of gamma rays, multiple radionuclides can be identified and quantified. Liquid scintillation counting is a low-background detection method capable of detecting extremely low levels of radionuclides; it has solid angle measurement conditions, enabling it to capture β particles emitted from any position in the sample, reducing measurement errors caused by different sample positions. It can also be used for the activity measurement of multiple nuclides. Using these two methods to detect the nuclide activity concentration in activated carbon allows for the simultaneous detection of multiple radionuclides, meeting the detection needs of different nuclides.

[0058] Furthermore, the analysis of sample nuclide activity concentration includes...3 H, 14 C 60 Co、 58 Co、 137 Cs、 134 Cs、 95 Zr、 95 Nb, 54 Mn, 59 Fe、 125 Sb、 124 Sb、 110m At least one of Ag. Specifically, 3 H and 14 C is a radioactive nuclide with a relatively long half-life found in nuclear power plants. Based on the detection results of the activity concentrations of these two nuclides, a preliminary judgment can be made on the radioactivity level of this batch of spent activated carbon. If the detection results of the activity concentrations of these two nuclides are less than 20% of the delimitation limit, it can be preliminarily considered that the radioactivity level of this batch of spent activated carbon is low. If the detection results of the activity concentrations of these two nuclides are greater than 20% of the delimitation limit, then the sample representativeness assessment step below is required. Detection 60 Co、 58 Co、 137 Cs、 134 Cs helps assess long-term radioactive contamination in spent activated carbon. 95 Zr、 95 Nb, 54 Mn, 59 Fe、 125 Sb、 124 Sb、 110m Ag helps assess recent radioactive contamination in spent activated carbon. Selecting these nuclides for testing is to comprehensively evaluate the radioactive contamination status of spent activated carbon, ensuring that the test results accurately reflect the radioactivity level of the entire batch of spent activated carbon, and providing a scientifically accurate basis for subsequent decontamination compliance assessments.

[0059] Preferably, the detection of sample nuclide activity concentration also includes 90 Sr、 55 Fe、 63 Ni et al., when 137 When Cs is higher than 0.004 Bq / g, proceed with... 90 Sr activity concentration measurement; when 60 When Co is higher than 0.004 Bq / g, proceed with... 55 Fe、 63 Ni activity concentration measurement.

[0060] S4. Conduct a compliance assessment of the analytical results with the release limits, including a representativeness assessment of the samples and a release limit assessment.

[0061] Furthermore, to ensure that the radionuclide activity concentration levels of the collected samples are representative of the overall batch of waste activated carbon radionuclide activity concentration levels, a sample representativeness assessment is conducted. The number of samples collected should reach the minimum sample number n required to achieve the confidence level (95%) calculated according to formula (1):

[0062]

[0063] In the formula, s: the standard deviation of the sample;

[0064] n: Number of samples;

[0065] The average value of the measured quantities of n samples;

[0066] If the number of samples collected is greater than or equal to the minimum number of samples calculated, then the control limit for this batch of waste activated carbon should be assessed to determine whether the control should be lifted.

[0067] If the number of samples collected is less than the minimum number of samples calculated, additional samples need to be collected until the number of samples collected is greater than or equal to the minimum number of samples calculated by formula (1).

[0068] The formula described above is used to calculate the minimum number of samples required for radionuclide activity concentration detection. This is to ensure that the collected samples accurately reflect the radionuclide activity concentration level of the entire batch of waste activated carbon, while avoiding excessive sample collection and reducing detection costs.

[0069] Furthermore, the decontrol limit assessment includes decontrol limit assessment for a single nuclide and / or decontrol limit assessment for a mixture of multiple nuclides;

[0070] The assessment of the delimitation limit for a single nuclide is based on the standard deviation of the sample mean calculated according to formula (2). Combined with sample average calculate like If the calculated value is lower than the limit of the release standard, it means that the release standard is met with a 95% confidence level. Formula (2) is as follows:

[0071]

[0072] In the formula, s: the standard deviation of the sample;

[0073] n: Number of samples;

[0074] Standard deviation of the sample mean;

[0075] For the assessment of the deregulation limits of the mixture of multiple nuclides, the sum of the ratios of the activity concentration of each radionuclide to its upper limit of activity concentration in the deregulation standard should satisfy formula (3):

[0076]

[0077] In the formula, C i : Activity concentration of the i-th artificial radionuclide in the material, Bq / g;

[0078] C oi : The upper limit of the activity concentration of the i-th artificial radionuclide in the de-control standard, Bq / g;

[0079] n: The number of artificial radionuclides present in the material, dimensionless.

[0080] In this application, the delimitation assessment includes delimitation assessment of a single nuclide and / or a mixture of multiple nuclides, aiming to more comprehensively and accurately assess the radioactivity level of spent activated carbon. For the delimitation assessment of a single nuclide, the standard deviation of the sample mean is first calculated using formula (2). Then, combine with the average value of the samples. Finally passed Calculating the activity concentration of a single nuclide enables accurate numerical control of its activity concentration, allowing for precise assessment of whether each nuclide's activity concentration meets the de-control standard. This ensures that the radioactivity level of each nuclide is below the de-control limit before de-control can be implemented, preventing the entire batch of waste activated carbon from failing to meet de-control requirements due to a single nuclide exceeding the limit. For the assessment of de-control limits for mixtures of multiple nuclides, formula (3) is used to calculate the ratio of the activity concentration of each nuclide to its upper limit in the de-control standard. This allows for a comprehensive assessment of the radioactivity levels of multiple nuclides, providing a more complete overall assessment of the radioactivity level of the waste activated carbon. This ensures that the overall radioactivity level meets the de-control standard and avoids overlooking potential radioactive risks due to the limitations of single-nuclide assessment. This dual assessment mechanism—assessing the de-control limits of a single nuclide and a mixture of multiple nuclides—not only improves the accuracy and scientific validity of the assessment results but also provides a reliable basis for subsequent diversion treatment.

[0081] The decontrol limits, half-lives, and detection methods for the radionuclides involved in this application are shown in Table 1:

[0082] Table 1. Reference Table for Radionuclide De-escalation Limits and Detection Methods

[0083]

[0084] S5. Based on the assessment results and de-control standards, the waste activated carbon will be diverted into hazardous waste or radioactive waste and disposed of accordingly.

[0085] Furthermore, if the assessment results meet the de-control criteria, the waste activated carbon will be packaged and transferred to a hazardous waste treatment facility for disposal as hazardous waste.

[0086] If the assessment results do not meet the de-control criteria, the waste activated carbon will be packaged and transferred to a radioactive waste treatment facility for disposal as radioactive solid waste.

[0087] After radionuclide activity concentration testing and assessment, and through a clearly defined diversion mechanism, spent activated carbon is diverted into hazardous waste or radioactive waste. This diversion mechanism has significant economic and environmental advantages. On the one hand, after diversion, only spent activated carbon that does not meet the release criteria is treated as radioactive waste. This means that activated carbon that would otherwise be classified entirely as radioactive waste can be treated as hazardous waste after testing and assessment, thus significantly reducing the economic expenditure of nuclear power plants on radioactive waste treatment. On the other hand, conventional radioactive waste treatment poses a significant environmental hazard. Diversion greatly reduces the amount of spent activated carbon that needs to be treated as radioactive waste, thereby significantly reducing the environmental impact. This diversion mechanism not only has significant economic advantages, reducing nuclear waste treatment costs, but also significant environmental advantages, demonstrating remarkable environmental friendliness.

[0088] The application and effects of the present invention will be further illustrated below through specific embodiments:

[0089] This nuclear power plant's iodine filter generates 15 tons of waste activated carbon. This embodiment employs the nuclear power plant radioactive activated carbon treatment method of this application, which involves shielding and temporarily storing the 15 tons of waste activated carbon, representative sampling and sample preparation, and... 3 H, 14 C 60 Co、 58 Co、 137 Cs、 134 Cs、 95 Zr、 95 Nb, 54 Mn, 59 Fe、 125 Sb、 124 Sb、 110m Ag、 90 Sr、 55 Fe、 63 The activity concentrations of nuclides such as Ni were measured, and the results were analyzed to assess compliance with the release limits. Finally, based on the assessment results and release standards, the spent activated carbon was diverted as hazardous waste or radioactive waste and disposed of accordingly. In contrast, the comparative method for treating radioactive activated carbon from nuclear power plants did not employ this application. The 15 tons of spent activated carbon generated from the iodine filter at the nuclear power plant were not assessed or diverted in any way and were directly disposed of as radioactive waste.

[0090] The mass comparison of different waste types generated in the embodiments of this application and the comparative examples is shown in Table 2 below:

[0091] Table 2. Comparison of the mass of different waste types generated by the embodiments of this application and the comparative examples.

[0092] Waste type Hazardous waste mass (tons) Mass of radioactive waste (tons) Example 12.75 2.25 Comparative Example 0 15

[0093] As shown in Table 2, the embodiment uses the nuclear power plant radioactive activated carbon treatment method of this application to treat 15 tons of waste activated carbon. Of this, 12.75 tons of waste activated carbon are treated as hazardous waste, and only 2.25 tons are treated as radioactive waste. In contrast, the comparative example treats all 15 tons of waste activated carbon as radioactive waste. It can be seen that the embodiment using the nuclear power plant radioactive activated carbon treatment method of this application effectively reduces the huge pressure on the environment caused by treating all waste activated carbon as radioactive waste, significantly reduces the amount of radioactive waste to be treated, and has significant environmental friendliness.

[0094] In nuclear power plant waste disposal, the cost of hazardous waste disposal is 960 yuan / ton, and the cost of radioactive waste disposal is 450,000 yuan / ton. Based on Table 2, the costs of treating different types of waste generated in the embodiments of this application and the comparative examples are compared to calculate the treatment costs of the waste activated carbon generated in the embodiments of this application and the comparative examples. A comparison of the treatment costs of the waste activated carbon generated in the embodiments of this application and the comparative examples is shown in Table 3 below:

[0095] Table 3. Comparison of waste activated carbon treatment costs between the embodiments of this application and the comparative examples.

[0096]

[0097] As shown in Table 3, the total cost of treating 15 tons of waste activated carbon using the nuclear power plant radioactive activated carbon treatment method of this application was RMB 1,024,740, while the total cost of treating 15 tons of waste activated carbon in the comparative example was RMB 6,750,000. It is evident that the embodiment of this application saves RMB 5,725,260 compared to the comparative example in treating 15 tons of waste activated carbon, demonstrating significant economic benefits.

[0098] As can be seen from this embodiment, the method for treating radioactive activated carbon in nuclear power plants proposed in this application not only excels in environmental friendliness but also has significant advantages in economic benefits. It can effectively reduce the expenditure on the treatment of waste activated carbon in nuclear power plants and has broad application prospects.

[0099] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

[0100] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for treating radioactive activated carbon of a nuclear power plant, applied to waste activated carbon of a ventilation system of a nuclear power plant, said ventilation system comprising an iodine filter, characterized in that, The method comprises the following steps: S1. Shielded storage of waste activated carbon after replacement of iodine filter; S2. Representative sampling and sample preparation of the waste activated carbon; S3. Detection and analysis of the activity concentration of sample nuclides; S4. Compliance evaluation of the analysis results and the control limit value; S5. According to the evaluation results and the control standard, the waste activated carbon is divided into hazardous waste or radioactive waste and corresponding disposal.

2. The method of claim 1, wherein the method further comprises, In step S1, the waste activated carbon after replacement of iodine filter is temporarily stored in a radiation shielding box.

3. The method of claim 1, wherein the method further comprises, In step S2, the representative sampling of waste activated carbon comprises the following steps: S31. Determine the sampling dimension, and divide the waste activated carbon temporary storage shielding box along the X-axis, Y-axis and Z-axis into a three-dimensional grid; S32. Layout sampling points, 1-5 sampling layers are laid out on the X-Y plane in the three-dimensional grid, and 1-8 sampling points are laid out in the Z-axis direction of each sampling layer; S33. Sub-sample collection, using a waste activated carbon special sampler to drill and sample, and drilling through the columnar activated carbon core of the X-Y plane where the sampling point is located as a sub-sample.

4. The method of claim 1, wherein the method further comprises, In step S2, the representative sample preparation of waste activated carbon is to crush, mix and fully stir the columnar activated carbon core obtained by drilling, and to collect the detection sample by using multi-dimensional sampling method, and finally to obtain the analysis sample.

5. The method of claim 1, wherein the method further comprises, In step S3, the detection and analysis of the activity concentration of sample nuclides uses γ energy spectrum method and / or liquid scintillation counting method.

6. The method of claim 1, wherein the method further comprises, In step S3, said detecting and analyzing the sample nuclide activity concentration comprises 3 H, 14 C, 60 Co, 58 Co, 137 Cs, 134 Cs, 95 Zr, 95 Nb, 54 Mn, 59 Fe, 125 Sb, 124 Sb, 110m Ag.

7. The method of claim 1, wherein the method further comprises, In step S4, the compliance evaluation of the analysis results and the control limit value comprises sample representativeness evaluation and control limit value evaluation.

8. The method of claim 7, wherein the method further comprises, In order to ensure that the activity concentration level of the collected sample represents the activity concentration level of the whole batch of waste activated carbon, the sample representativeness evaluation is carried out, and the number of collected samples should reach the minimum number of samples n calculated according to formula (1) at a confidence level (95%): Wherein, s: standard deviation of the sample; n: number of samples; the average of the determined amounts of the n samples. If the number of collected samples is more than or equal to the calculated minimum number of samples, it is evaluated according to the control limit value whether the batch of waste activated carbon is controlled; If the number of collected samples is less than the calculated minimum number of samples, the collected samples need to be supplemented until the number of collected samples is more than or equal to the minimum number of samples calculated by formula (1).

9. The method of claim 7, wherein the method further comprises, The control limit value evaluation includes single nuclide control limit value evaluation or / and multi-nuclide mixture control limit value evaluation; The single isotope limit of control assessment is the standard deviation of the sample mean calculated according to equation (2) In combination with the sample mean Calculation If The calculated value of 0.0003 is below the limit of the control standard, indicating compliance with the control standard at the 95% confidence level, according to equation (2): Wherein, s: standard deviation of the sample; n: number of samples; Standard deviation of the sample mean; Or / and, the multi-nuclide mixture control limit value evaluation, the sum of the ratio of the activity concentration of each radioactive nuclide to the upper limit of the activity concentration in the control standard should satisfy formula (3): wherein C i : activity concentration of the i-th artificial radionuclide in the material, Bq / g; C oi : Upper limit value of the activity concentration in the control standard, Bq / g; n: the number of artificial radioactive nuclides existing in the material, dimensionless.

10. The method of claim 1-9, wherein the method is a method of treating a nuclear power plant radioactive carbon, characterized by, In step S5, the corresponding disposal is: If the evaluation result meets the control standard, the waste activated carbon is packaged and handed over to the hazardous waste treatment facility as hazardous waste for disposal; If the evaluation result does not meet the control standard, the waste activated carbon is packaged and handed over to the radioactive waste treatment facility as radioactive solid waste for disposal.

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