RFID-based use safety supervision method for exemption-level radioactive source

Abstract

The invention discloses an RFID-based exempt-level radioactive source use safety supervision method, and particularly relates to the technical field of radioactive source use supervision, and the method comprises the steps: printing an RFID tag on each radioactive source container in an exempt-level radioactive source storage cabinet, writing initial data, and reserving a digital fingerprint field; detecting the energy spectrum diagrams of the radioactive sources one by one, extracting characteristic energy distribution and peak values, converting the characteristic energy distribution and peak values into digital expressions, and uploading the digital expressions to a data management center. And performing binary hash processing on the digital data to obtain a digital fingerprint, and writing the digital fingerprint into the RFID tag. When a worker carries out taking-out operation, RFID data are read and uploaded through a reader, and the state of the radioactive source is updated. And during the storage operation, detecting the characteristic energy data of the radioactive source to be stored and triggering digital fingerprint verification. If the verification is passed, the storage is allowed, and if the verification is not passed, whether collocation error or source replacement exists is judged, and the radioactive source state is updated according to a result.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive source use supervision, and more specifically, to an RFID-based exemption-level radioactive source use safety supervision method. Background Art

[0002] Exempted radioactive sources are radioactive sources whose radioactivity does not reach the minimum limit specified in the "Radioactive Source Classification Method" and whose long-term exposure will not cause significant radiation damage to the human body. However, due to the particularity of the radioactive source itself, it should still be strictly managed during use to prevent abuse and misplacement by non-staff members, which may cause safety hazards. The traditional management method of exempted radioactive sources usually relies on manual registration and simple physical identification, such as labels and log records. However, this management method has many defects, mainly manifested in the omission of manual operation and insufficient real-time monitoring of the status of radioactive sources. In many cases, radioactive sources may be accidentally replaced or misplaced due to frequent human contact, storage and access operations, etc. In addition, due to the lack of an effective tracking and authentication mechanism, it is difficult to record the use status of radioactive sources in real time and accurately, which may make it difficult to trace responsibility and deal with source management issues in the event of an accident. Based on these shortcomings, the existing management method has failed to effectively prevent storage errors or source replacement attacks, and cannot ensure the safety and compliance of radioactive sources during use.

[0003] Therefore, how to analyze the characteristics of the radioactive source itself and integrate its radiation characteristic detection with RFID tag technology to achieve an RFID-based safety supervision method for the use of exempted radioactive sources, which can be used to supervise storage errors or source replacement attacks during use and ensure the safety and compliance of radioactive sources during use, is an urgent problem that needs to be solved.

[0004] In order to solve the above problems, a technical solution is now provided. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides an RFID-based exempted-level radioactive source use safety supervision method to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: S1: Put an RFID tag on each radioactive source container in the exempted radioactive source storage cabinet and write the initial data, and reserve a digital fingerprint field; S2: Detect the energy spectrum of each radiation source one by one, extract the characteristic energy distribution and peak value in the energy spectrum, convert the characteristic energy distribution and peak value into digital expression and upload them to the data management center; S3: performing binary hashing to preserve similarity on the digital expressions of characteristic energy distribution and peak value to obtain a digital fingerprint corresponding to the radiation source, and writing the digital fingerprint into a digital fingerprint field reserved in the RFID tag; S4: When the staff performs the removal operation, the RFID tag data is read and uploaded through the opening and closing control reader of the storage cabinet door, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to have been removed; S5: When the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the digital fingerprint verification is triggered; S6: verifying the digital fingerprint of the radioactive source to be stored, and calculating the difference degree of the digital fingerprint recognition of the radioactive source to be stored; S7: Retrieve the historical records of characteristic energy distribution attenuation after use of each radioactive source, and set a dynamic digital fingerprint recognition difference threshold; S8: Based on the difference in the digital fingerprint recognition of the radioactive source to be stored, determine whether the digital fingerprint is verified. If so, allow the radioactive source to be stored. If not, further determine whether the radioactive source to be stored is incorrectly placed or replaced by a source, and modify the status of the radioactive source according to the determination result.

[0007] In a preferred embodiment, in S1, each radioactive source container in the exempted radioactive source storage cabinet is tagged with an RFID tag and initial data is written, and a digital fingerprint field is reserved, specifically including: Obtain all radioactive source containers in the exempted radioactive source storage cabinet, select active RFID tags with long-distance recognition capabilities, and adhere the RFID tags to the surface of the radioactive source containers; Assign a unique identifier to the RFID tag of each radioactive source container, and use an RFID programming device to write initial data into the tag storage area, the initial data including the type of radioactive source, activity value, and status of the radioactive source; A space is reserved in the RFID tag storage area for storing the digital fingerprint field of the radioactive source, and the initial value of the field is set to empty.

[0008] In a preferred embodiment, in S2, detecting the energy spectrum of each radiation source one by one, extracting the characteristic energy distribution and peak value in the energy spectrum, converting the characteristic energy distribution and peak value into digital expression and uploading them to the data management center specifically includes: Based on the type of exempted radioactive sources, a lightweight energy spectrum detection instrument with the required monitoring energy range is selected, and the energy spectrum detection instrument is calibrated using a standard energy source; Use the energy spectrum detection instrument to perform one-by-one detection of the radioactive sources in the exempted radioactive source storage cabinet, obtain the energy spectrum of each radioactive source, extract the characteristic energy distribution and peak value in the energy spectrum of the radioactive source and convert it into a digital expression: The energy signal of the extracted characteristic energy distribution is quantized into a discrete digital signal through analog-to-digital conversion, and each energy point corresponds to a count value; The local maximum value of each up and down cycle in the characteristic energy distribution is extracted by the sliding window method and marked as the energy peak value, and the peak energy point and count value corresponding to the energy peak value, as well as the full width half maximum value, are obtained; The digital expression of characteristic energy distribution and peak value is recorded, and the digital expression is converted into a structured storage format and uploaded to the data management center.

[0009] In a preferred embodiment, in S3, the digital expressions of the characteristic energy distribution and the peak value are subjected to binary hash processing with similarity retention to obtain a digital fingerprint corresponding to the radiation source, and the digital fingerprint is written into a digital fingerprint field reserved in the RFID tag, specifically including: The digital expression of characteristic energy distribution and peak value corresponding to each radiation source is obtained at the data management center, and the digital expression data is converted into a character string without any symbol information; The string is processed using a binary hash algorithm that retains similarity to obtain a unique digital fingerprint of a fixed length, which is then written into the digital fingerprint field in the RFID tag storage area using an RFID programming device.

[0010] In a preferred embodiment, in S4, when the staff performs the removal operation, the RFID tag data is read and uploaded by the reader of the storage cabinet door opening and closing control, and the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to be removed, which specifically includes: Install a staff identification system on the door of the storage cabinet. After the staff has confirmed their identity, they can choose to deposit or withdraw. An RFID reader is provided in the radioactive source storage cabinet, and a control element connected to the door of the storage cabinet is built in; If the staff chooses to take out the radioactive source, the RFID tag on the radioactive source container in the storage cabinet is scanned once when the cabinet door is opened and closed to read the tag data, and the RFID tag data with the reading timestamp is uploaded and updated to the data management center; The data management center compares the two received data, marks the status of the radioactive source in the RFID tag with missing tag data in the second upload as removed, and uses the timestamp of the cabinet door opening as the removal time of the radioactive source.

[0011] In a preferred embodiment, in S5, when the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the triggering of the digital fingerprint verification specifically includes: If the staff chooses to store the radioactive source, a lightweight energy spectrum detection instrument will be used to detect the radioactive source to be stored, obtain the characteristic energy distribution and peak data in the energy spectrum of the radioactive source to be stored, upload the data to the data management center, and trigger digital fingerprint verification at the same time.

[0012] In a preferred embodiment, in S6, the digital fingerprint verification is performed on the radioactive source to be stored, and the calculation of the digital fingerprint identification difference of the radioactive source to be stored specifically includes: Recalculate the digital fingerprint corresponding to the radioactive source to be stored in the data management center, and mark the fingerprint as a comparison fingerprint; At the data management center, based on the unique identifier of the RFID tag corresponding to the radioactive source to be stored, the digital fingerprint stored in the corresponding digital fingerprint field is retrieved, and the Hamming distance between the digital fingerprint and the comparison fingerprint is calculated; The ratio of the Hamming distance to the digital fingerprint length is marked as the digital fingerprint identification difference of the radioactive source to be stored.

[0013] In a preferred embodiment, the RFID tag unique identifier corresponding to the radiation source is used to retrieve the digital fingerprint change history of the radiation source in the data management center; The retrieved digital fingerprint change history records are grouped and counted according to the interval time between taking out and returning, and the average value of the digital fingerprint recognition difference of the digital fingerprint verification records in each statistical group is calculated; Obtain the interval time between the retrieval and return of the radioactive source to be stored, perform historical mean matching of the digital fingerprint recognition difference, set the acceptable range of recognition deviation, and comprehensively determine the dynamic digital fingerprint recognition difference threshold of the radioactive source to be stored.

[0014] In a preferred embodiment, in S8, based on the difference of the digital fingerprint recognition of the radioactive source to be stored, it is determined whether the digital fingerprint is verified. If so, the radioactive source to be stored is allowed to be stored. If not, it is further determined whether the radioactive source to be stored is misplaced or replaced by a source. Modifying the state of the radioactive source according to the determination result specifically includes: Based on the set dynamic digital fingerprint recognition difference threshold, if the recognition difference calculated in the digital fingerprint verification of the radioactive source to be stored is less than the recognition difference threshold, it is judged that the digital fingerprint verification has passed, and the storage cabinet door is opened to allow the radioactive source to be stored, and the state of the radioactive source is marked as placed, and the placement time is recorded; Update the compared fingerprint in the identification process as a new digital fingerprint into the digital fingerprint field in the RFID tag; If the identification difference of the radioactive source to be stored calculated in the digital fingerprint verification is greater than or equal to the identification difference threshold, it is judged that the digital fingerprint verification has not passed, and the radioactive source to be stored is prohibited from being stored in the storage cabinet; Retrieve and extract digital fingerprints of radioactive sources marked as removed from all RFID data in the data management center, and integrate them into a digital fingerprint group; Calculate the identification difference between the comparison fingerprint and the digital fingerprint group that failed the digital fingerprint verification. If the calculation result shows that there is a digital fingerprint with an identification difference less than a set identification difference threshold, mark the radioactive source state corresponding to the comparison and the compared digital fingerprint as a placement error. If there is no digital fingerprint in the digital fingerprint group whose identification difference is less than the set identification difference threshold, the state of the radioactive source to be stored is marked as a suspected source replacement, and an alarm message is sent.

[0015] The technical effects and advantages of the RFID-based exemption-level radioactive source use safety supervision method of the present invention are as follows: By attaching an RFID tag to each radioactive source and writing a digital fingerprint into it, accurate identification and tracking of the radioactive source can be achieved, thereby ensuring that the source, status and location of the radioactive source can always be traced. The generation of the digital fingerprint is based on the characteristic energy spectrum data of the radioactive source. This data is highly stable and unique, and is not easily tampered with or forged, thereby effectively avoiding source replacement attacks and illegal operations. The digital expression of energy spectrum data and its hash processing ensure the safe storage and transmission of radioactive source information, and can verify the radioactive source at any time, and promptly detect and prevent misoperation or improper access. By combining RFID tags with digital fingerprint verification, when the radioactive source is taken out or stored, the system can identify and update the status in real time, enhancing the automation and intelligence level of radioactive source management.

[0016] This method not only improves the management efficiency of radioactive sources and reduces the risk of human intervention, but also provides strong data support for safety supervision, ensuring that the use of exempted radioactive sources meets strict safety requirements and can greatly improve the safety and reliability of radioactive source management. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic diagram of a method for safely supervising the use of exempted-level radioactive sources based on RFID. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Embodiment 1:

[0019] Figure 1 The present invention provides a method for safely supervising the use of exempted-level radioactive sources based on RFID, which comprises the following steps: S1: Put an RFID tag on each radioactive source container in the exempted radioactive source storage cabinet and write the initial data, and reserve a digital fingerprint field; S2: Detect the energy spectrum of each radiation source one by one, extract the characteristic energy distribution and peak value in the energy spectrum, convert the characteristic energy distribution and peak value into digital expression and upload them to the data management center; S3: performing binary hashing to preserve similarity on the digital expressions of characteristic energy distribution and peak value to obtain a digital fingerprint corresponding to the radiation source, and writing the digital fingerprint into a digital fingerprint field reserved in the RFID tag; S4: When the staff performs the removal operation, the RFID tag data is read and uploaded through the opening and closing control reader of the storage cabinet door, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to have been removed; S5: When the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the digital fingerprint verification is triggered; S6: verifying the digital fingerprint of the radioactive source to be stored, and calculating the difference degree of the digital fingerprint recognition of the radioactive source to be stored; S7: Retrieve the historical records of characteristic energy distribution attenuation after use of each radioactive source, and set a dynamic digital fingerprint recognition difference threshold; S8: Based on the difference in the digital fingerprint recognition of the radioactive source to be stored, determine whether the digital fingerprint is verified. If so, allow the radioactive source to be stored. If not, further determine whether the radioactive source to be stored is incorrectly placed or replaced by a source, and modify the status of the radioactive source according to the determination result.

[0020] In S1, an RFID tag is attached to each radioactive source container in the exempted radioactive source storage cabinet and initial data is written, and a digital fingerprint field is reserved.

[0021] Obtain all radioactive source containers in the exempted radioactive source storage cabinet. When selecting RFID tags, give priority to active RFID tags with long-distance recognition capabilities. Active RFID tags have self-powered functions and can effectively communicate with readers through radio waves at a long distance, ensuring accurate and stable data transmission between multiple radioactive source containers in the storage cabinet.

[0022] According to the shape and material of each radioactive source container, choose the appropriate installation method to adhere the RFID tag to the surface of the container. The RFID tag should be installed in a position that will not affect the function of the radioactive source container and ensure that it can be stably read during subsequent operations.

[0023] Assign a globally unique identifier (UID) to each RFID tag, which should correspond to the radioactive source container and can be used to uniquely identify the container in subsequent operations. This identifier needs to correspond one-to-one with the radioactive source information in the database to avoid duplication or conflict. Use an RFID programming device to write initial data to the tag. The initial data should include but is not limited to the type of radioactive source (such as cobalt-60, cesium-137, etc.), the activity value of the radioactive source (such as Becquerel Bq or Curie Ci units), and the current status of the radioactive source (such as "in stock", "taken out"). After writing the initial data, verify the RFID tag to ensure that all data has been successfully stored in the tag storage area. Read the data in the tag through the verification program to ensure that it is consistent with the radioactive source information in the database.

[0024] A space is reserved in the RFID tag storage area for storing the digital fingerprint field of the radioactive source, and the initial value of the field is set to empty.

[0025] In S2, the energy spectrum of each radiation source is detected one by one, the characteristic energy distribution and peak value in the energy spectrum are extracted, and the characteristic energy distribution and peak value are converted into digital expressions and uploaded to the data management center.

[0026] Based on the type of exempted radioactive source, a lightweight energy spectrum detection instrument with the required monitoring energy range (flexibly set according to the type of radioactive source, the default setting is 500keV to 1.5MeV) is selected, and the energy spectrum detection instrument is calibrated using a standard energy source (such as cobalt-60, cesium-137 and other radioactive sources with a known energy spectrum).

[0027] Use the calibrated spectrum detector to test each radioactive source in the exempted radioactive source storage cabinet one by one. During each test, the detector should be placed in front of the radioactive source to ensure that the measurement angle and position are appropriate, and obtain the energy spectrum of the radioactive source within the set energy range. Through real-time data acquisition, the energy distribution diagram of each radioactive source is recorded in the instrument memory.

[0028] The extracted characteristic energy distribution is converted from an analog signal to a discrete digital signal using an analog-to-digital converter (ADC). Each energy point corresponds to a specific count value (i.e., radiation intensity value) in the digital signal. These discrete values ​​form a universal digital representation of the energy spectrum of the radiation source: (energy point, radiation count value). For example, the radiation count value of 50 at an energy point of 100KeV can be converted into a digital format (100,50).

[0029] The energy distribution in the energy spectrum is analyzed using a sliding window algorithm. A sliding window is set to calculate the local maximum (energy peak) of the energy distribution within the window. The size of the sliding window can be set according to the measurement accuracy and signal noise level. For each marked energy peak, its corresponding peak energy point and count value are determined. The peak energy point is the highest point in the energy distribution, and the peak count value is the radiation intensity corresponding to the point. At the same time, the full width half maximum (FWHM) of each energy peak is calculated. This value reflects the width of the peak. The integrated digital expression is (peak energy point, peak radiation count value, full width half maximum).

[0030] The digital expression of characteristic energy distribution and peak value is recorded, and the digital expression is converted into a structured storage format and uploaded to the data management center.

[0031] In S3, the digital expressions of the characteristic energy distribution and the peak value are subjected to binary hash processing with similarity preservation to obtain the digital fingerprint corresponding to the radiation source, and the digital fingerprint is written into the digital fingerprint field reserved in the RFID tag.

[0032] The digital expression of the characteristic energy distribution and peak value corresponding to each radioactive source is obtained at the data management center, and the obtained digital expression data is converted into a string without any symbol information. This string should only contain numbers and their relative relationships. For example, a specific separator (such as a comma, space, or unsigned fixed-length field) is used to sequentially combine the digital data into a pure digital sequence. For example, the digital expression of the characteristic energy distribution and peak value of a sample may be converted into the following string: [11, 12, 15, 17, 20].

[0033] Apply a similarity-preserving binary hash algorithm (SimHash) to the pure digital string obtained from each radioactive source. SimHash is an efficient hash algorithm that represents the input data by generating a fixed-length binary hash value while preserving the similarity information between the data as much as possible. For the digital expression of different radioactive sources, SimHash can obtain a fixed-length hash value (such as 64 bits or 128 bits), which serves as a unique identifier of the radioactive source to ensure that each radioactive source has a unique digital fingerprint (the hash value is theoretically collision-resistant, so that similar data inputs will hardly produce the same hash output). The following is a specific example: Map each number in [11, 12, 15, 17, 20] to a simple binary feature vector through a custom hash function. The number 11 corresponds to the feature vector: [1, 0, 0, 1, -1], the number 12 corresponds to the feature vector: [1, 1, -1, 0, 1], the number 15 corresponds to the feature vector: [0, -1, 1, 1, 1], the number 17 corresponds to the feature vector: [-1, 1, 1, -1, 0], and the number 20 corresponds to the feature vector: [0, -1, -1, 1, -1]; The specific result of adding the feature vectors of all numbers one by one is: [1+1+0-1+0,0+1-1+1-1, 0-1+1+1-1,1+0+1-1+1,-1+1+1+0-1] = [1,0,0,0,0]. The final vector is generated by symbolizing (i.e. taking the sign) the vector after weighted summation. Usually, if an element is greater than 0, the element is 1; if it is less than 0, the element is -1. In this way, the symbolized vector obtained is: [1, 0, 0, 0, 0], and the final hash value is expressed as 10000.

[0034] The generated digital fingerprint is written into the digital fingerprint field of the RFID tag through the RFID programming device. This field is used to store the digital fingerprint of each radioactive source, which will be used to verify the identity and status of the radioactive source in the subsequent detection and management process.

[0035] According to the half-life of the nuclide of the radioactive source, an automatic update cycle is set to regularly update the digital fingerprint in the RFID tag. This cycle can be determined based on the decay rate and nuclide characteristics of the radioactive source. Generally, radioactive sources with shorter half-lives need to update digital fingerprints more frequently, while radioactive sources with longer half-lives can have a relatively longer update cycle (half-lives are generally longer, and the update cycle can be set in years).

[0036] In S4, when the staff performs the removal operation, the RFID tag data is read and uploaded through the opening and closing control reader of the storage cabinet door, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to have been removed.

[0037] Install a staff identification system on the cabinet door, using technologies such as fingerprint recognition, facial recognition or card recognition to ensure that only authorized personnel can operate the access to the radioactive source. This system should be connected to the control system of the storage cabinet to prevent unauthorized personnel from operating the cabinet door by verifying the identity of the employee. The system automatically records the staff's identity information and operation type while confirming the identity. The data should include information such as the staff's unique identifier, operation type (deposit or withdraw), and operation time. These data will provide a basis for subsequent traceability.

[0038] The RFID reader is connected to the cabinet's control element, which triggers the cabinet door to open and close. This connection allows the reader to automatically start reading the RFID tag when the cabinet door is opened and end reading when the cabinet door is closed, ensuring a complete read record for each operation.

[0039] If the staff chooses to take out the radioactive source, the RFID tag on the radioactive source container in the storage cabinet is scanned once when the cabinet door is opened and closed to read the tag data, and the RFID tag data with the reading timestamp is uploaded and updated to the data management center; The data management center compares the two received data, marks the status of the radioactive source in the RFID tag with missing tag data in the second upload as removed, and uses the timestamp of the cabinet door opening as the removal time of the radioactive source.

[0040] In S5, when the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, triggering the digital fingerprint verification.

[0041] If the staff chooses to store the radioactive source, a lightweight spectrum detection instrument is used to detect the radioactive source to be stored, obtain the characteristic energy distribution and peak data in the spectrum of the radioactive source to be stored, and convert the extracted characteristic energy distribution and energy peak data into digital form. Each energy point in the characteristic energy distribution and the corresponding count value (radiation intensity) are converted into discrete digital signals through an analog-to-digital converter (ADC). For the energy peak, the local maximum value is extracted through algorithms such as the sliding window method and stored digitally, including peak energy, count value and full-width half-maximum (FWHM). The data is uploaded to the data management center, and digital fingerprint verification is triggered at the same time.

[0042] In S6, the digital fingerprint of the radioactive source to be stored is verified, and the difference degree of the digital fingerprint recognition of the radioactive source to be stored is calculated.

[0043] The latest energy spectrum data of the radioactive source to be stored is obtained in the data management center, and the digital fingerprint corresponding to the radioactive source to be stored is recalculated by the SimHash algorithm, and the fingerprint is marked as a comparison fingerprint.

[0044] The data management center retrieves the corresponding digital fingerprint field through the stored RFID tag unique identifier (UID). The data successfully retrieved through the UID includes the digital fingerprint stored in the RFID tag. This fingerprint represents the initial characteristics of the radioactive source and has been written into the RFID tag storage area when the radioactive source was initially registered. The method of calculating the Hamming distance is used to compare the comparison fingerprint stored in the data management center and the digital fingerprint stored in the RFID tag. The Hamming distance is a measure of the degree of difference between two strings. The calculation requires comparing two binary strings bit by bit and calculating the number of different bits. This value reflects the difference between the two digital fingerprints. The smaller the Hamming distance, the more similar the characteristics of the radioactive source to be stored are to the source characteristics already in the database, and the higher the probability of passing the fingerprint verification; conversely, when the Hamming distance is large, there may be a risk of source replacement or data error.

[0045] The difference degree of the digital fingerprint identification of the radioactive source to be stored is calculated by comparing the calculated Hamming distance with the total length of the digital fingerprint. This ratio can effectively reflect the degree of difference between the two, and quantify the similarity of the source characteristics through the difference metric.

[0046] In S7, the digital fingerprint change history record of the radioactive source to be stored is retrieved, and a dynamic digital fingerprint recognition difference threshold is set.

[0047] When determining the difference threshold of dynamic digital fingerprint identification, it is necessary to consider the usage time of the radioactive source and the attenuation characteristics of the radiation intensity. Over time, the radiation intensity of the radioactive source will decrease due to radioactive decay, which will in turn affect its energy spectrum data and digital fingerprint. A radioactive source with a faster decay may produce a larger digital fingerprint difference, while a radioactive source with a slower decay may maintain a smaller difference. In the analysis of the same radioactive source, the usage time is one of the main factors affecting its radiation intensity attenuation.

[0048] Based on the unique identifier of the RFID tag corresponding to the radioactive source to be stored, obtain all digital fingerprint change records of the radioactive source since its first storage from the data management center. The records should cover each retrieval and return of the radioactive source, including the timestamp and corresponding digital fingerprint data of each operation. Extract the interval time between each retrieval and return of the radioactive source. These timestamp information is used to analyze the digital fingerprint change trend of the radioactive source in different use cycles.

[0049] According to the interval between the retrieval and return of the radioactive source, the historical records are divided into multiple statistical groups. Each statistical group represents the use of the radioactive source within a specific time interval. For example, it can be grouped by short-term (such as 3 days), medium-term (such as 1 month), long-term (such as 1 year and above) time periods. In each statistical group, the records that have passed the digital fingerprint verification are screened out, and the mean of the digital fingerprint recognition difference of these records is calculated. The digital fingerprint recognition difference indicates the degree of similarity between the digital fingerprint of the radioactive source currently to be stored and the verified fingerprint in the historical records. These averages reflect the stability of the digital fingerprint of the radioactive source (that is, the degree of attenuation of the radiation intensity of the radioactive source) and the law of changes in the use process within a specific time period.

[0050] Obtain the interval time between the retrieval and return of the radioactive source to be stored, match the historical mean of the digital fingerprint recognition difference, set the acceptable range of recognition deviation (specifically set based on the similarity of the energy distribution of the stored radioactive source, the default setting is 3.13%, that is, in addition to the calculated recognition difference mean, 1 bit error is allowed for every 32 bits), add the calculated recognition difference mean and the set recognition deviation acceptable range, and comprehensively determine the dynamic digital fingerprint recognition difference threshold of the radioactive source to be stored.

[0051] In S8, based on the difference in digital fingerprint recognition of the radioactive source to be stored, it is determined whether the digital fingerprint is verified. If so, the radioactive source to be stored is allowed to be stored. If not, it is further determined whether the radioactive source to be stored is incorrectly placed or replaced by a source, and the status of the radioactive source is modified according to the determination result.

[0052] Based on the set dynamic digital fingerprint recognition difference threshold, if the recognition difference calculated in the digital fingerprint verification of the radioactive source to be stored is less than the recognition difference threshold, it is judged that the digital fingerprint verification has passed, and the storage cabinet door is opened to allow the radioactive source to be stored, and the state of the radioactive source is marked as placed, and the placement time is recorded; Update the compared fingerprint in the identification process as a new digital fingerprint into the digital fingerprint field in the RFID tag; If the identification difference of the radioactive source to be stored calculated in the digital fingerprint verification is greater than or equal to the identification difference threshold, it is determined that the digital fingerprint verification has failed, and the radioactive source to be stored is prohibited from being stored in the storage cabinet.

[0053] The digital fingerprints of the radioactive source status marked as removed in all RFID data are retrieved and extracted in the data management center and integrated into a digital fingerprint group.

[0054] The identification difference of the comparison fingerprint and the digital fingerprint group that failed the digital fingerprint verification is calculated one by one. If the calculation result shows that there is a digital fingerprint with an identification difference less than the set identification difference threshold (indicating that the radioactive source taken out at this time has a radioactive source that matches the digital fingerprint stored in the RFID of the container to be stored), the status of the radioactive source corresponding to the digital fingerprint being compared and compared is marked as a placement error.

[0055] If there is no digital fingerprint in the digital fingerprint group whose identification difference is less than the set identification difference threshold (indicating that the radioactive source taken out at this time does not match the digital fingerprint stored in the RFID of the container to be stored), the status of the radioactive source to be stored is marked as suspected source replacement, and an alarm message is sent.

[0056] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters and thresholds in the formula are set by technicians in this field according to actual conditions.

[0057] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or may be transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that contains one or more available media sets. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium may be a solid-state hard disk.

[0058] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0059] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0060] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0061] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, and may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0062] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0063] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0064] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0065] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for safe supervision of the use of exempted radioactive sources based on RFID, characterized in that: The steps include: S1: Put an RFID tag on each radioactive source container in the exempted radioactive source storage cabinet and write the initial data, and reserve a digital fingerprint field; S2: Detect the energy spectrum of each radiation source one by one, extract the characteristic energy distribution and peak value in the energy spectrum, convert the characteristic energy distribution and peak value into digital expression and upload them to the data management center; S3: performing binary hashing to preserve similarity on the digital expressions of characteristic energy distribution and peak value to obtain a digital fingerprint corresponding to the radiation source, and writing the digital fingerprint into a digital fingerprint field reserved in the RFID tag; S4: When the staff performs the removal operation, the RFID tag data is read and uploaded through the opening and closing control reader of the storage cabinet door, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to have been removed; S5: When the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the digital fingerprint verification is triggered; S6: verifying the digital fingerprint of the radioactive source to be stored, and calculating the difference degree of the digital fingerprint recognition of the radioactive source to be stored; S7: Retrieve the historical records of characteristic energy distribution attenuation after use of each radioactive source, and set a dynamic digital fingerprint recognition difference threshold; S8: Based on the difference in the digital fingerprint recognition of the radioactive source to be stored, determine whether the digital fingerprint is verified. If so, allow the radioactive source to be stored. If not, further determine whether the radioactive source to be stored is incorrectly placed or replaced by a source, and modify the status of the radioactive source according to the determination result.

2. According to claim 1, a method for safe supervision of the use of exempted radioactive sources based on RFID is characterized in that: In S1, an RFID tag is added to each radioactive source container in the exempted radioactive source storage cabinet and initial data is written. At the same time, a digital fingerprint field is reserved, including: Obtain all radioactive source containers in the exempted radioactive source storage cabinet, select active RFID tags with long-distance recognition capabilities, and adhere the RFID tags to the surface of the radioactive source containers; Assign a unique identifier to the RFID tag of each radioactive source container, and use an RFID programming device to write initial data into the tag storage area, the initial data including the type of radioactive source, activity value, and status of the radioactive source; A space is reserved in the RFID tag storage area for storing the digital fingerprint field of the radioactive source, and the initial value of the field is set to empty.

3. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 2, characterized in that: In S2, the energy spectrum of each radiation source is detected one by one, the characteristic energy distribution and peak value in the energy spectrum are extracted, and the characteristic energy distribution and peak value are converted into digital expressions and uploaded to the data management center. Specifically, it includes: Based on the type of exempted radioactive sources, a lightweight energy spectrum detection instrument with the required monitoring energy range is selected, and the energy spectrum detection instrument is calibrated using a standard energy source; Use the energy spectrum detection instrument to perform one-by-one detection on the radioactive sources in the exempted radioactive source storage cabinet, obtain the energy spectrum of each radioactive source, extract the characteristic energy distribution and peak value in the energy spectrum of the radioactive source and convert it into digital expression: The energy signal of the extracted characteristic energy distribution is quantized into a discrete digital signal through analog-to-digital conversion, and each energy point corresponds to a count value; The local maximum value of each up and down cycle in the characteristic energy distribution is extracted by the sliding window method and marked as the energy peak value, and the peak energy point and count value corresponding to the energy peak value, as well as the full width half maximum value, are obtained; The digital expression of characteristic energy distribution and peak value is recorded, and the digital expression is converted into a structured storage format and uploaded to the data management center.

4. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 3, characterized in that: In S3, the digital expressions of the characteristic energy distribution and the peak value are subjected to binary hash processing with similarity preservation to obtain the digital fingerprint corresponding to the radiation source, and the digital fingerprint is written into the digital fingerprint field reserved in the RFID tag. Specifically, it includes: The digital expression of characteristic energy distribution and peak value corresponding to each radiation source is obtained at the data management center, and the digital expression data is converted into a character string without any symbol information; The string is processed using a binary hash algorithm that retains similarity to obtain a unique digital fingerprint of a fixed length, which is then written into the digital fingerprint field in the RFID tag storage area using an RFID programming device.

5. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 4, characterized in that: In S4, when the staff performs the removal operation, the RFID tag data is read and uploaded through the storage cabinet door opening and closing control reader, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to be removed, which specifically includes: Install a staff identification system on the door of the storage cabinet. After the staff has confirmed their identity, they can choose to deposit or withdraw. An RFID reader is provided in the radioactive source storage cabinet, and a control element connected to the door of the storage cabinet is built in; If the staff chooses to take out the radioactive source, the RFID tag on the radioactive source container in the storage cabinet is scanned once when the cabinet door is opened and closed to read the tag data, and the RFID tag data with the reading timestamp is uploaded and updated to the data management center; The data management center compares the two received data, marks the status of the radioactive source in the RFID tag with missing tag data in the second upload as removed, and uses the timestamp of the cabinet door opening as the removal time of the radioactive source.

6. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 5, characterized in that: In S5, when the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the triggering of digital fingerprint verification specifically includes: If the staff chooses to store the radioactive source, a lightweight energy spectrum detection instrument will be used to detect the radioactive source to be stored, obtain the characteristic energy distribution and peak data in the energy spectrum of the radioactive source to be stored, upload the data to the data management center, and trigger digital fingerprint verification at the same time.

7. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 6, characterized in that: In S6, the digital fingerprint verification is performed on the radioactive source to be stored, and the digital fingerprint identification difference of the radioactive source to be stored is calculated, which specifically includes: Recalculate the digital fingerprint corresponding to the radioactive source to be stored in the data management center, and mark the fingerprint as a comparison fingerprint; At the data management center, based on the unique identifier of the RFID tag corresponding to the radioactive source to be stored, the digital fingerprint stored in the corresponding digital fingerprint field is retrieved, and the Hamming distance between the digital fingerprint and the comparison fingerprint is calculated; The ratio of the Hamming distance to the digital fingerprint length is marked as the digital fingerprint identification difference of the radioactive source to be stored.

8. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 7, characterized in that: In S7, the digital fingerprint change history record of the radioactive source to be stored is retrieved, and the dynamic digital fingerprint recognition difference threshold is set, which specifically includes: Based on the unique identifier of the RFID tag corresponding to the radioactive source to be stored, the digital fingerprint change history of the radioactive source is retrieved in the data management center; The retrieved digital fingerprint change history records are grouped and counted according to the interval time between taking out and returning, and the average value of the digital fingerprint recognition difference of the digital fingerprint verification records in each statistical group is calculated; Obtain the interval time between the retrieval and return of the radioactive source to be stored, perform historical mean matching of the digital fingerprint recognition difference, set the acceptable range of recognition deviation, and comprehensively determine the dynamic digital fingerprint recognition difference threshold of the radioactive source to be stored.

9. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 8, characterized in that: In S8, based on the difference of the digital fingerprint recognition of the radioactive source to be stored, it is determined whether the digital fingerprint is verified. If so, the radioactive source to be stored is allowed to be stored. If not, it is further determined whether the radioactive source to be stored is misplaced or replaced by a source. Modifying the state of the radioactive source according to the determination result specifically includes: Based on the set dynamic digital fingerprint recognition difference threshold, if the recognition difference calculated in the digital fingerprint verification of the radioactive source to be stored is less than the recognition difference threshold, it is judged that the digital fingerprint verification has passed, and the storage cabinet door is opened to allow the radioactive source to be stored, and the state of the radioactive source is marked as placed, and the placement time is recorded; Update the compared fingerprint in the identification process as a new digital fingerprint into the digital fingerprint field in the RFID tag; If the identification difference of the radioactive source to be stored calculated in the digital fingerprint verification is greater than or equal to the identification difference threshold, it is judged that the digital fingerprint verification has not passed, and the radioactive source to be stored is prohibited from being stored in the storage cabinet; Retrieve and extract digital fingerprints of radioactive sources marked as removed from all RFID data in the data management center, and integrate them into a digital fingerprint group; Calculate the identification difference between the comparison fingerprint and the digital fingerprint group that failed the digital fingerprint verification. If the calculation result shows that there is a digital fingerprint with an identification difference less than a set identification difference threshold, mark the radioactive source state corresponding to the comparison and the compared digital fingerprint as a placement error. If there is no digital fingerprint in the digital fingerprint group whose identification difference is less than the set identification difference threshold, the state of the radioactive source to be stored is marked as a suspected source replacement, and an alarm message is sent.

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