Activation source term tracing method for nuclear reaction chain search based on characteristic symbol ordering

Abstract

The application discloses an activation source item tracing method based on characteristic symbol ordering nuclear reaction chain search, which can know whether a nuclide is stable and the kind of the daughter nuclide of the nuclide through the known information of the nuclide reaction in the search process. After the initial nuclide is determined, the nuclide and the corresponding characteristic symbol are recorded in two different data sets respectively. When all the daughter nuclides reach stability or the linear chain cannot be extended, the characteristic symbols are sorted. After the sorting is completed, the data set is segmented and completed. Finally, a complete nuclear reaction chain is quickly and accurately obtained, the activation source item is obtained, the reaction process in the reactor can be intervened in time, and targeted measures such as removing material impurities, material replacement, adjusting operation conditions and processes and the like are taken, so that the activation source item is reduced, the radiation damage to the staff is reduced, and the safety of the reactor is ensured.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor technology, specifically to a nuclear reaction chain search method based on feature symbol sorting and a method for tracing activation source terms using the same method. Background Technology

[0002] Nuclear reactor fuel is the core of a nuclear power plant's operation. During reactor operation, changes in the fuel's nuclide composition alter its neutron properties, affecting the reactor core's reactivity and safety parameters. Furthermore, various materials in the reactor core are activated under neutron irradiation, transforming into radioactive nuclides. The decay reactions of these radioactive nuclides release various high-energy rays, causing radiation damage to personnel and the environment. Therefore, real-time analysis and control of various radioactive source terms in the nuclear reactor (fission source terms, activated corrosion product source terms, coolant activation source terms, material activation source terms, building gas source terms, effluent source terms, etc.) are necessary to ensure the safety of the nuclear power plant and the surrounding population.

[0003] Furthermore, the nuclide composition of materials is usually quite complex (e.g., containing various trace elements or impurities), and theoretically, the same initial nuclide can generate multiple different radioactive product nuclides through different nuclear reactions, and the same radioactive product nuclide can also be generated by multiple initial nuclides. Therefore, there is a complex network correspondence between initial nuclides and product nuclides. The process from initial nuclide to product nuclide is affected by the operating conditions of the nuclear reactor (neutron flux and neutron energy spectrum) and the operating history (irradiation time and shutdown time). This means that even if the initial nuclide composition of the material and the number of neutron-activated product nuclides can be accurately measured, it is difficult to quickly give the generation path of the product nuclides and the contribution ratio of each path. This is the source tracing problem of activation source terms that has troubled those skilled in the art.

[0004] The issue of tracing the source of activation terms is of great value to nuclear reactor radiation protection. Knowing the nuclide source and reaction pathway of activation terms allows for targeted measures (such as removing material impurities, material substitution, and adjusting operating conditions and processes) to reduce activation terms, thereby minimizing radiation damage to workers.

[0005] For the reasons mentioned above, the inventors have conducted in-depth research on activation source term tracing methods in order to design an activation source term tracing method that can improve tracing efficiency and be applied to specific nuclear reactor safety protection. Summary of the Invention

[0006] To overcome the aforementioned problems, the inventors conducted in-depth research and designed a method for tracing activation source terms in nuclear reaction chain search based on feature symbol sorting. This method, using known information about nuclide reactions, can determine the stability of a nuclide and the types of its progeny nuclides during the search process. After determining the initial nuclide, the nuclide and its corresponding feature symbol are recorded in two different datasets. When all progeny nuclides reach stability or the linear chain can no longer extend, the feature symbols are sorted. After sorting, the dataset is segmented and completed, ultimately obtaining complete nuclear reaction chains quickly and accurately, thus identifying activation source terms. This allows for timely intervention in the reactor reaction process, enabling targeted measures such as removing material impurities, material substitution, and adjusting operating conditions and processes, thereby reducing activation source terms, minimizing radiation damage to workers, and ensuring reactor safety, thus completing this invention.

[0007] Specifically, the purpose of this invention is to provide a method for tracing activation source terms in nuclear reaction chain search based on feature symbol sorting, the method comprising the following steps:

[0008] Step 1: Retrieve nuclide information from the database;

[0009] Step 2: Analyze and store the nuclides involved in the nuclide reaction and their numbers;

[0010] Step 3: Sort the stored nuclide numbering data;

[0011] Step 4: Split the nuclide numbering data to obtain a preliminary linear chain;

[0012] Step 5: Copy the linear chain fragment to obtain the nuclear reaction chain;

[0013] Step 6: Eliminate nuclear reaction chains where the endpoint nuclide is not the target nuclide to obtain the activation source term.

[0014] In step 2, the nuclide and its number are stored in two datasets, V1 and V2, respectively.

[0015] Step 2 includes the following sub-steps:

[0016] Sub-step 2-1: Create empty datasets V1 and V2.

[0017] Sub-step 2-2: Add the initial nuclide to V1 and store the corresponding number of the initial nuclide in V2 accordingly;

[0018] Sub-steps 2-3 add the offspring nuclides of each nuclide previously added to dataset V1 to dataset V1, replacing them with a cutoff symbol when no offspring nuclide exists.

[0019] When adding a nuclide to V1, the corresponding number of that nuclide is simultaneously added to V2.

[0020] When adding a terminator to V1, the corresponding number of that terminator is simultaneously added to V2.

[0021] Sub-steps 2-4 are repeated, and sub-steps 2-3 are executed until the number of feature symbols contained in the longest number in the current V2 meets the preset chain length requirement, or the last element added to V1 is a stop symbol.

[0022] The number corresponding to the nuclide is obtained by adding the nuclide's own code after the number of the parent nuclide of the corresponding nuclide. The nuclide's own code includes a characteristic symbol and the nuclide's sorting i.

[0023] The number corresponding to the stop symbol is obtained by adding a characteristic symbol and the number 1 after the number of the superior nuclide of the stop symbol.

[0024] In step 3, the numbers in V2 are sorted to obtain a new dataset. Preferably, the numbers in V2 are sorted from smallest to largest according to the same rules as the AS CII code values.

[0025] Step 4 includes the following sub-steps:

[0026] Sub-step 4-1: Check the dataset one by one from beginning to end. For each number in the dataset, if the number of features in the preceding number is greater than the number of features in the following number, save the preceding number and all numbers before it in the new dataset T1, and load the following number and all numbers after it into the new dataset T2.

[0027] Sub-step 4-2: Check each number in dataset T2 one by one. When the number of features in the adjacent earlier number is greater than the number of features in the later number, keep the earlier number and all the numbers before it in dataset T2, and transfer the later number and all the numbers after it into the new dataset T3.

[0028] Sub-step 4-3: Repeat sub-step 4-2 above, continuously providing new datasets until the last number in the new dataset is determined, and the last number and the numbers before it are stored in the new dataset. The final combination of numbers in each new dataset is the initial linear chain.

[0029] Step 5 includes the following sub-steps:

[0030] Sub-step 5-1: Read the first number in the preliminary linear chain, select the preliminary linear chain containing the number corresponding to the initial nuclide, and perform deduplication on it to obtain the complete linear chain;

[0031] Sub-step 5-2: retrieve the preliminary linear chain that does not contain the corresponding number of the initial nuclide, extract the first number in the preliminary linear chain, delete the last feature character and the numbers following it in the first number to obtain a temporary number;

[0032] Sub-step 5-3: Compare the temporary number with each number in the latest obtained complete linear chain, find the number in the complete linear chain that is the same as the temporary number, take the same number and all the numbers before it in the complete linear chain as a linear chain segment, and copy it;

[0033] Sub-step 5-4: Copy the linear chain segment to the beginning of the initial linear chain, and perform deduplication on the new linear chain to obtain the complete linear chain;

[0034] Sub-step 5-5, repeat sub-step 5-2, sub-step 5-3 and sub-step 5-4 until all the preliminary linear chains are processed and a complete linear chain is obtained;

[0035] Sub-steps 5-6 involve obtaining the nuclear reaction chain by combining the corresponding numbers based on the order of the numbers in the complete linear chain.

[0036] The deduplication process includes the following sub-steps:

[0037] Step 1: Read and record the number of feature symbols for each number in the linear chain to be deduplicated, starting from the back and working backwards.

[0038] In step 2, when the number of feature symbols in the last number is different from the number of feature symbols in the adjacent numbers before it, the linear chain is a complete linear chain.

[0039] Step 3: When the number of feature symbols of the last number is the same as the number of feature symbols of its preceding adjacent numbers, record the value of the number of feature symbols. Filter out the numbers with the same number of feature symbols from the back to the front, count the number of such numbers as n, and then convert the linear chain to be deduplicated into n complete linear chains.

[0040] In step 3, all the numbers before the last n numbers in the linear chain to be deduplicated are taken as the front segment numbers, and each of the n numbers is taken as a back segment number. The combination of the front segment number and any back segment number is a complete linear chain. The n back segment numbers are combined to form n complete linear chains.

[0041] The beneficial effects of this invention include:

[0042] (1) The method for tracing the activation source term of nuclear reaction chain search based on feature symbol sorting provided by the present invention uses feature symbols to reduce the problem of forward path searching, and obtains a complete linear chain by sorting the feature symbols. This makes the method different from DFS, where each nuclide only needs to go through once. This greatly reduces the time for searching nuclear reaction chain, and thus enables timely tracing of activation source term, ensuring the normal operation of the nuclear reactor. Attached Figure Description

[0043] Figure 1 The overall logic diagram of the activation source term tracing method based on feature symbol sorting in nuclear reaction chain search according to the present invention is shown.

[0044] Figure 2 A simplified schematic diagram of a nuclide network according to an embodiment of the present invention is shown;

[0045] Figure 3 A simplified schematic diagram of a nuclide network according to an embodiment of the present invention is shown;

[0046] Figure 4 The diagram shows the inter-nucleinary reaction network involved in the first three steps of the reaction starting with O-16. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more apparent.

[0048] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0049] The activation source term tracing method for nuclear reaction chain search based on feature symbol sorting provided by the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0050] Step 1: Retrieve nuclide information from the database;

[0051] The nuclide information includes information about nuclide reactions, that is, the process by which a nuclide transforms into other nuclides through a reaction. Correspondingly, other nuclides can also be further transformed through reactions. For ease of understanding, a nuclide network can be visualized based on the reaction information of multiple nuclides that are continuously transformed.

[0052] The database mentioned in this application may be the EAF-2007 database. For ease of understanding, a nuclide network is visualized based on the retrieved nuclide information; this nuclide network is a network format formed by linking nuclides through nuclear reactions. Figure 2 The diagram shows a very simplified representation of a nuclide network. Figure 2 Each box contains a letter representing a nuclide, and the direction of the arrow indicates the direction of nuclide transformation. For example, nuclide A can be transformed into nuclide B and nuclide C, while nuclide E can only be transformed into nuclide I. The nuclear reaction chain in this application is a single-direction chain composed of nuclides and arrows. This nuclide network contains multiple nuclear reaction chains, such as a nuclear reaction chain composed of nuclide A, nuclide B, and nuclide D, or a nuclear reaction chain composed of nuclide A, nuclide C, nuclide F, nuclide G, and nuclide H, etc. The relationship between nuclides F, G, and H is a cyclic chain.

[0053] The predetermined nuclide network mentioned in this application refers to a nuclide network with an initial nuclide selected, where the initial nuclide is the starting point of the nuclide network, such as... Figure 2 Nuclide A in the diagram is the initial nuclide in the nuclide network.

[0054] Step 2: Analyze and store the nuclides involved in the nuclide reaction and their numbers;

[0055] Step 2 in this application includes the following sub-steps:

[0056] Sub-step 2-1: Create empty datasets V1 and V2, which are storage spaces used to store the data;

[0057] In sub-step 2-2, add the initial nuclide A to V1 and store the corresponding number of the initial nuclide A in V2, such as the string "P0", i.e., V1 = [A], V2 = [P0]. The string of the initial nuclide number can be set arbitrarily, as long as it will not cause confusion due to duplication with other number contents.

[0058] Sub-steps 2-3 add the offspring nuclides of each nuclide previously added to dataset V1 to dataset V1, replacing them with a stop symbol if no offspring nuclide exists.

[0059] Preferably, in sub-step 2-3, when sub-step 2-3 has not been repeated, the previous addition refers to the process of adding the initial nuclide when executing sub-step 2-2; when sub-step 2-3 has been repeated, the previous addition refers to the process of adding nuclides when executing sub-step 2-3 last time. If two nuclides were added when sub-step 2-3 was executed last time, then all sub-nuclides of those two nuclides should be added to dataset V1 when executing sub-step 2-3 this time. For example... Figure 2 In the network, since the nuclides added to dataset V1 during the first execution of sub-step 2-3 are nuclides B and C, the nuclides added to dataset V1 during the second execution of sub-step 2-3 are nuclides D, E, and F.

[0060] Preferably, the terminator is "END"; in this application, daughter nuclides and parent nuclides correspond to each other, the parent nuclide can be directly converted into daughter nuclides, and the daughter nuclide is the parent nuclide of the daughter nuclides it can be converted into, for example... Figure 2 In this context, nuclide A is the parent nuclide of nuclide B, and both nuclide B and nuclide C are daughter nuclides of nuclide A.

[0061] When adding a nuclide to V1, the corresponding number of that nuclide is simultaneously added to V2. In this application, each nuclide has a corresponding number, and each number also corresponds to a nuclide. The number corresponding to the nuclide is obtained by adding the nuclide's own code after the number of its parent nuclide. The nuclide's own code includes a characteristic symbol and the nuclide's order i. The nuclide's order i refers to the fact that the nuclide is the i-th descendant nuclide of its parent nuclide, and the value of i is a positive integer, for example... Figure 2 Nuclide E is the second daughter nuclide of nuclide B, and the corresponding i value is 2; the feature symbol can be any common character such as " / " or "-", and the character must not have appeared in this method to avoid confusion;

[0062] When adding a terminator to V1, the corresponding number of that terminator is simultaneously added to V2.

[0063] The number corresponding to the stop symbol is obtained by adding a characteristic symbol and the number 1 after the number of the superior nuclide of the stop symbol. For example, in this application Figure 2 Nuclide D in V1 does not have any daughter nuclides. When it is necessary to add a daughter nuclide of nuclide D to V1, only a stop symbol is added to V1 accordingly. The parent nuclide of the stop symbol is nuclide D.

[0064] Sub-steps 2-4 are repeated, and sub-steps 2-3 are executed until the number of feature symbols contained in the longest number in the current V2 meets the preset chain length requirement, or the last element added to V1 is a stop symbol.

[0065] The element described in this application is a constituent unit of the dataset, which can be a nuclide or a stop symbol.

[0066] The chain length requirement mentioned in this application refers to the desired length of the nuclear reaction chain, which is the number of nuclides that make up the chain. In practice, nuclear reaction chains are extremely complex and can consist of hundreds of nuclides. Obtaining a complete nuclear reaction chain requires a considerable amount of time, which may affect the timeliness of activation source term tracing. Therefore, this application saves time in obtaining the nuclear reaction chain by setting a reasonable desired length, while also ensuring the reasonableness of the length setting, thereby ensuring that the obtained nuclear reaction chain can meet the requirements for activation source term tracing and ensuring the accuracy of activation source term tracing.

[0067] The longest number contains a number of signatures that meet the preset chain length requirement, which means that the number of signatures contained in the longest number is less than the number of nuclides that make up the nuclear reaction chain by 1.

[0068] When the preset chain length requirement is 7, this step 2 is used for processing. Figure 2 The nucleoside network obtained from this dataset yielded the following datasets V1 and V2:

[0069] V1=[A,B,C,D,E,F,End,I,G,End,H,F,G]

[0070]

[0071] In this application, by setting step 2, nuclides and their numbers are stored separately. Since the numbers contain digits, the numbering based on the numbers can be sorted quickly and conveniently, thereby improving the efficiency of obtaining nuclear reaction chains, shortening the traversal process and time, and meeting the practical application needs of activation source terms.

[0072] Step 3: Sort the stored nuclide numbering data;

[0073] In step 3, the numbers in V2 are sorted to obtain a new dataset. Preferably, the numbers in V2 are sorted from smallest to largest according to the same rules as the ASCII code values. This yields the dataset. The data stored in the dataset is sorted from front to back and from smallest to largest according to a predetermined order. The sorting process is primarily based on the numerical values ​​following each feature symbol in the serial number. Serial numbers without a feature symbol correspond to the initial nuclide and are placed first. Since the serial number preceding the first feature symbol is the same for all serial numbers, the serial number / number preceding the first feature symbol is disregarded. First, the number following the first feature symbol is considered, with smaller numbers placed first. For serial numbers with the same number, the number following the second feature symbol is considered, again with smaller numbers placed first. If a second feature symbol does not exist, the corresponding number is considered to be 0. The dataset is sorted according to this rule. Sort all data / numbers in the database.

[0074] In this application, the sorting operation in step 3 achieves the preliminary sorting of the corresponding numbers of nuclides in the nuclear reaction chain. That is, it realizes the sorting of the numbers of most nuclides in the same nuclear reaction chain according to the order of nuclides in the nuclear reaction chain, providing an accurate sorting basis for subsequent processing. At the same time, since this sorting scheme is the same as the ASCII code value sorting rule, it is easy to identify and sort by computer. All numbers only need to be traversed once during the sorting process, which is fast and saves processing time, providing a time guarantee for timely acquisition of nuclear reaction chains and traceability of activation source items.

[0075] Based on the results obtained in step 2 above Figure 2 The result of sorting V2 with chain length 7 in step 3. as follows:

[0076]

[0077] Preferably, in step 3, records can also be made. The number of feature symbols for each number is stored, so that subsequent processing can be performed directly based on the stored number, without having to count the number of feature symbols separately.

[0078] Step 4: Split the nuclide numbering data to obtain a preliminary linear chain;

[0079] Step 4 includes the following sub-steps:

[0080] Sub-step 4-1: Check dataset V2 one by one from beginning to end. * For each number in the dataset, if the number of features in an earlier number is greater than the number of features in a later number, save the earlier number and all numbers preceding it in the new dataset T1, and load the later number and all numbers following it into the new dataset T2; for example, process V2 obtained in step 3 above. * The analysis revealed that the number of feature symbols in the fourth number P0-1-2-1 (3) is greater than the number of feature symbols in the fifth number P0-1-2 (2). Therefore, the new datasets T1 and T2 are obtained as follows: T1 = [P0, P0-1, P0-1-1, P0-1-1-1].

[0081]

[0082] Sub-step 4-2: Each number in dataset T2 is evaluated sequentially. If the number of characteristic symbols in an earlier number is greater than the number of characteristic symbols in a later number, the earlier number and all numbers preceding it are stored in dataset T2, while the later number and all numbers following it are transferred to the new dataset T3. For example, continuing to process dataset T2 obtained in sub-step 4-1, it is found that the number of characteristic symbols (4) in the third number P0-1-2-1-1 is greater than the number of characteristic symbols (1) in the fourth number P0-2. Therefore, the new datasets T2 and T3 are as follows.

[0083] T2=[P0-1-2, P0-1-2-1, P0-1-2-1-1]

[0084] T3=[P0-2, P0-2-1, P0-2-1-1, P0-2-1-1-1, P0-2-1-1-1-1, P0-2-1-1-1-1-1]

[0085] Sub-step 4-3 repeats sub-step 4-2 above, continuously providing new datasets T. m This process continues until the last number in the new dataset is determined, and this last number, along with the numbers preceding it, is stored in the new dataset. The final combination of numbers in each of the new datasets constitutes the initial linear chain. Where T... m Let T3 represent the m-th new dataset. In T3 obtained from sub-step 4-2 above, there is no longer a case where the number of features in the earlier adjacent numbers is greater than the number of features in the later numbers, so T3 is the last new dataset.

[0086] In this application, the splitting operation in step 4 yields multiple new datasets. The number in each new dataset corresponds to one or more nuclear reaction chains. That is, the splitting operation initially obtains the preliminary linear chains of nuclides in the nuclear reaction chains, providing a foundation for obtaining complete linear chains and nuclear reaction chains in the future. The splitting operation is simple and easy to perform, and can be completed in a very short time, providing a time guarantee for timely tracing of the activation source items.

[0087] Step 5: Copy the linear chain fragment to obtain the nuclear reaction chain;

[0088] Step 5 includes the following sub-steps:

[0089] Sub-step 5-1: Read the first number in the preliminary linear chain, select the preliminary linear chain containing the number corresponding to the initial nuclide, and perform deduplication on it to obtain the complete linear chain; for example, based on the one obtained in step 4 above... Figure 2 The chains T1, T2, and T3, with a chain length of 7, are processed using the method in sub-step 5-1. T1 contains the initial nuclide corresponding numbers. The complete linear chain obtained after deduplication is as follows:

[0090] T1=[P0, P0-1, P0-1-1, P0-1-1-1]

[0091] Sub-step 5-2: Retrieve the preliminary linear chain that does not contain the number corresponding to the initial nuclide, extract the first number in the preliminary linear chain, delete the last feature character and the numbers following the first number to obtain a temporary number, and store it in a temporary character; for example, continue to process T1, T2, and T3 obtained in step 4 above using sub-step 5-2, in which the preliminary linear chain corresponding to T2 is retrieved, the first number P0-1-2 in the preliminary linear chain is extracted, the last feature character and the numbers following the first number are deleted to obtain the temporary number P0-1.

[0092] Sub-step 5-3: Compare the temporary number with each number in the newly obtained complete linear chain, find the number in the complete linear chain that is the same as the temporary number, and take that same number and all the numbers preceding it as a linear chain segment, and copy it; for example, the temporary number obtained in sub-step 5-3 is P0-1, and the newly obtained complete linear chain is the one obtained in sub-step 5-1.

[0093] T1=[P0, P0-1, P0-1-1, P0-1-1-1];

[0094] Find the second number in the complete linear chain T1 that is the same as the temporary number, which is P0-1; take the same number P0-1 and all the numbers before it in the complete linear chain T1 as the linear chain segment, that is, the linear chain segment is [P0, P0-1].

[0095] Sub-step 5-4 involves copying the linear chain segment to the beginning of the initial linear chain and performing a deduplication process on the resulting new linear chain to obtain a complete linear chain. For example, continuing with the linear chain segment [P0, P0-1] from sub-step 5-3, the new linear chain obtained by sub-step 5-4 is T2 = [P0, P0-1, P0-1-2, P0-1-2-1, P0-1-2-1-1]. The complete linear chain obtained by the deduplication process is consistent with this new linear chain, i.e., it remains the same.

[0096] T2=[P0, P0-1, P0-1-2, P0-1-2-1, P0-1-2-1-1];

[0097] Sub-step 5-5, repeat sub-steps 5-2, 5-3, and 5-4 until all the initial linear chains are processed, resulting in a complete linear chain; for example, in sub-step 5-2, the initial linear chain corresponding to T3 is retrieved, and the final complete linear chain is consistent with this new linear chain, that is:

[0098] T3=[P0, P0-2, P0-2-1, P0-2-1-1, P0-2-1-1-1, P0-2-1-1-1-1, P0-2-1-1-1-1-1];

[0099] Sub-steps 5-6 involve combining the corresponding numbers in the complete linear chain to obtain the nuclear reaction chain. Since each number corresponds to a unique nuclide, the order of the nuclides can be obtained based on the order of the numbers. For example, the complete linear chain obtained above is as follows:

[0100] T1=[P0, P0-1, P0-1-1, P0-1-1-1]

[0101] T2=[P0, P0-1, P0-1-2, P0-1-2-1, P0-1-2-1-1]

[0102] T3=[P0, P0-2, P0-2-1, P0-2-1-1, P0-2-1-1-1, P0-2-1-1-1-1, P0-2-1-1-1-1-1]

[0103] The nuclear reaction chain obtained by further processing in sub-steps 5-6 is as follows:

[0104] W1 = [A, B, D, End]

[0105] W2 = [A, B, E, I, End]

[0106] W3=[A,C,F,G,H,F,G]

[0107] In this application, the incomplete linear chain is completed through the supplementary operation in step 5, thereby obtaining the corresponding complete linear chain, and then obtaining the nuclear reaction chain. The completion operation in step 5 is simple and easy to perform. Only a small number of numbers need to be traversed to obtain the linear chain fragment. The subsequent process is still to traverse a small number of numbers to obtain the complete linear chain. The processing efficiency of step 5 is extremely high and can be completed in a very short time, providing a time guarantee for timely acquisition of the activation source item traceability.

[0108] The plagiarism detection process described in this application includes the following sub-steps:

[0109] Step 1: Read and record the number of feature symbols for each number in the linear chain to be deduplicated, starting from the back and working backwards.

[0110] In step 2, when the number of feature symbols in the last number is different from the number of feature symbols in the adjacent numbers before it, the linear chain is a complete linear chain.

[0111] Step 3: When the number of feature symbols of the last number is the same as the number of feature symbols of its preceding adjacent numbers, record the value of the number of feature symbols. Filter out the numbers with the same number of feature symbols from the back to the front, count the number of such numbers as n, and then convert the linear chain to be deduplicated into n complete linear chains.

[0112] In step 3, all the numbers before the last n numbers in the linear chain to be deduplicated are taken as the front segment numbers, and each of the n numbers is taken as a back segment number. The combination of the front segment number and any back segment number is a complete linear chain. The n back segment numbers are combined to form n complete linear chains.

[0113] This application distinguishes nuclear reaction chains of the same length through the above-mentioned deduplication process, forming different complete linear chains. Moreover, the differentiation process is simple and convenient, requiring only the traversal of a very small number of numbers. The processing speed is fast and can be completed in a very short time, providing a time guarantee for timely acquisition of the activation source item traceability.

[0114] Step 6: Eliminate nuclear reaction chains where the endpoint nuclide is not the target nuclide to obtain the activation source term.

[0115] Assume that there exists such Figure 3 The reaction network shown, with A, B, C, and D as initial nuclides and Q as the target nuclide, was searched using the method described above, resulting in the following nuclear reaction chain:

[0116] A→E→K→P

[0117] A→F→L→Q

[0118] B→G→M→Q

[0119] C→H→N→R→S

[0120] D→I→N→R→S

[0121] D→J→O

[0122] In the results, the linear chains A→E→K→P, C→H→N→R→S, D→I→N→R→S, and D→J→O do not terminate at Q, thus failing the condition. These chains are removed in subsequent checks, resulting in the correct outcome.

[0123] A→F→L→Q

[0124] B→G→M→Q

[0125] The results show that the initial nuclides that produced nuclide Q were A and B.

[0126] This completes the source tracing of the activation term, with the target nuclide Q as the endpoint and the initial nuclides A and B as the starting points.

[0127] After tracing the source of the activation term, we know the origin and reaction pathway of the target nuclide, further obtain the contribution ratio of each pathway, and finally give targeted measures to reduce the activation term.

[0128] Example:

[0129] Light water is the coolant in pressurized water reactors. Containing a large amount of oxygen, it can produce radioactive nuclides under prolonged irradiation, posing a radiation hazard to reactor operators and maintenance personnel. To clearly understand the origin of these nuclides, it is necessary to trace the activation source term and obtain the contribution ratio of each linear chain.

[0130] The light water is composed of H-1, H-2, O-16, O-17, and O-18. O-16 activation is used as the initial nuclide, and the chain search criterion is solely based on chain length as the cutoff criterion. The chain length is selected in the range of 3-10.

[0131] The specific processing procedure is as follows:

[0132] Step 1: Retrieve all nuclide information for related nuclides starting with O-16 from the EAF-2007 database; construct the nuclide reaction network diagram for the first three steps of the reaction starting with O-16, as shown below. Figure 4 As shown;

[0133] Step 2 specifically includes the following sub-steps:

[0134] Sub-step 2-1: Create empty datasets V1 and V2, which are storage spaces used to store the data;

[0135] Sub-step 2-2: Add the initial nuclide in the nuclide network to V1, and store the corresponding number of the initial nuclide in V2 accordingly;

[0136] Sub-steps 2-3 add the offspring nuclides of each nuclide previously added to dataset V1 to dataset V1, replacing them with a cutoff symbol when no offspring nuclide exists.

[0137] Sub-steps 2-4 are repeated, and sub-steps 2-3 are executed until the number of feature symbols contained in the longest number in the current V2 meets the preset chain length requirement, or the last element added to V1 is a stop symbol; where the preset nuclear reaction chain length is 3-10, that is, repeated 8 times, each time giving a different reaction chain length;

[0138] Step 3: Sort the nuclide identification information data stored in V2 based on the AS CII code values ​​to obtain the dataset.

[0139] Step 4 specifically includes the following sub-steps:

[0140] Sub-step 4-1: Check the dataset one by one from beginning to end. For each number in the dataset, if the number of feature symbols in the earlier number is greater than the number of feature symbols in the later number, the earlier number and all the numbers before it are saved in the new dataset T1, and the later number and all the numbers after it are loaded into the new dataset T2.

[0141] Sub-step 4-2: Check each number in dataset T2 one by one. When the number of features in the earlier number is greater than the number of features in the later number, keep the earlier number and all the numbers before it in dataset T2, and transfer the later number and all the numbers after it into the new dataset T3.

[0142] Step 4-3: Repeat sub-step 4-2 above, continuously providing new datasets until the last number in the new dataset is determined, and the last number and the numbers before it are stored in the new dataset. The final combination of numbers in each new dataset is the initial linear chain.

[0143] Step 5 specifically includes the following sub-steps:

[0144] Sub-step 5-1: Read the first number in the preliminary linear chain, select the preliminary linear chain containing the number corresponding to the initial nuclide, and perform deduplication on it to obtain the complete linear chain;

[0145] Sub-step 5-2: retrieve the preliminary linear chain that does not contain the corresponding number of the initial nuclide, extract the first number in the preliminary linear chain, delete the last feature character and the numbers following it in the first number to obtain a temporary number, and store it in a temporary character.

[0146] Sub-step 5-3: Compare the temporary number with each number in the latest obtained complete linear chain, find the number in the complete linear chain that is the same as the temporary number, take the same number and all the numbers before it in the complete linear chain as a linear chain segment, and copy it;

[0147] Sub-step 5-4: Copy the linear chain segment to the beginning of the initial linear chain, and perform deduplication on the new linear chain to obtain the complete linear chain;

[0148] Sub-step 5-5, repeat sub-step 5-2, sub-step 5-3 and sub-step 5-4 until all the preliminary linear chains are processed and a complete linear chain is obtained;

[0149] Sub-steps 5-6 involve combining the corresponding numbers in the complete linear chain to obtain the nuclear reaction chain.

[0150] Step 5, the deduplication process, includes the following sub-steps:

[0151] Step 1: Read and record the number of feature symbols for each number in the linear chain to be deduplicated, starting from the back and working backwards.

[0152] In step 2, when the number of feature symbols in the last number is different from the number of feature symbols in the adjacent numbers before it, the linear chain is a complete linear chain.

[0153] Step 3: When the number of feature symbols of the last number is the same as the number of feature symbols of its preceding adjacent numbers, record the value of the number of feature symbols. Filter out the numbers with the same number of feature symbols from the back to the front, count the number of such numbers as n, and then convert the linear chain to be deduplicated into n complete linear chains.

[0154] In step 3, all the numbers before the last n numbers in the linear chain to be deduplicated are taken as the front segment numbers, and each of the n numbers is taken as a back segment number. The combination of the front segment number and any back segment number is a complete linear chain. The n back segment numbers are combined to form n complete linear chains.

[0155] Step 6: Determine the target nuclide based on the chain length, and eliminate nuclear reaction chains where the endpoint nuclide is not the target nuclide to obtain the activation source term.

[0156] The number of elements added, the number of chains obtained, and the time to complete the tracing of the activation source item were statistically analyzed under different chain lengths. The tracing time of the activation source item was 14.337 seconds.

[0157] Comparative example:

[0158] Using O-16 activation as the initial nuclide, the chain search criterion is solely based on chain length as the cutoff criterion. The chain length is selected from 3 to 10. The specific search method is the traditional TTA depth search method, which is a search attempt process similar to enumeration. Starting from a head node, the search proceeds inwards towards the depth of the nuclear reaction until a nuclide no longer undergoes other reactions or meets the pre-set cutoff criterion. Then, the search backtracks to the previous nuclide in the reaction chain to check for other unreacted reaction pathways. If so, this nuclide is used as the new node to continue the search inwards. If not, the search backtracks to the previous nuclide and continues until the head node of the reaction chain is reached, thus completing the search for relevant reactions for all initial nuclides. The activation source term tracing results obtained in the examples and comparative examples are consistent, but the time taken is different. The activation source term tracing time in the comparative example is 77.828 seconds.

[0159] Further statistical analysis of the tracing time for different chain lengths is as follows:

[0160]

[0161] The results show that, within the range of chain length selection of 3-10, the efficiency of the activation source item tracing method provided in this application is significantly improved compared with the traditional TTA depth search method.

[0162] The present invention has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present invention based on these embodiments, all of which fall within the scope of protection of the present invention.

Claims

1. A method for tracing activation source terms in nuclear reaction chain search based on feature symbol sorting, characterized in that, The method includes the following steps: Step 1: Retrieve nuclide information from the database; Step 2: Analyze and store the nuclides involved in the nuclide reaction and their numbers; Step 3: Sort the stored nuclide numbering data; Step 4: Split the nuclide numbering data to obtain a preliminary linear chain; Step 5: Copy the linear chain fragment to obtain the nuclear reaction chain; Step 6: Eliminate nuclear reaction chains where the endpoint nuclide is not the target nuclide to obtain the activation source term; In step 2, the nuclide and its number are stored in two datasets respectively. and middle; Step 2 includes the following sub-steps: Sub-step 2-1: Create an empty dataset and , Sub-step 2-2, add the initial nuclide In the middle, correspondingly in The initial nuclide number is stored in the memory. Sub-steps 2-3: Add data to the dataset Add the last one added to the dataset The daughter nuclides of each nuclide in the list are replaced by a stop symbol when no daughter nuclide exists. In the direction When adding nuclides, simultaneously add to Add the corresponding number for the nuclide; In the direction When adding a deadline, synchronously send to Add the number corresponding to the cutoff symbol; Sub-steps 2-4 are repeated, along with sub-steps 2-3, until the current state is reached. The longest number contains a number of feature symbols that meet the preset chain length requirement, or the last one added to the chain. All elements in the list are delimiters; The number corresponding to the nuclide is obtained by adding the nuclide's own code to the number of its parent nuclide. The nuclide's own code includes a characteristic symbol and the nuclide's order. The feature symbol is any one of the characters " / " or "-". The number corresponding to the stop symbol is obtained by adding a characteristic symbol and the number 1 after the number of the superior nuclide of the stop symbol; In step 3, for Sort the numbers in the dataset to obtain a new dataset. Based on and Rules with the same code value Sort the numbers in the array from smallest to largest; Step 4 includes the following sub-steps: Sub-step 4-1: Check the dataset one by one from beginning to end. For each number in the dataset, if the number of feature symbols in an earlier number is greater than the number of feature symbols in a later number, then that earlier number and all numbers preceding it are saved in the new dataset. In the process, the number following the given number and all subsequent numbers are imported into the new dataset. middle; Sub-step 4-2: Check each dataset one by one. For each number in the dataset, if the number of feature symbols in an earlier number is greater than the number of feature symbols in a later number, then that earlier number and all numbers preceding it are saved in the dataset. In the process, the number following the given number and all subsequent numbers are imported into the new dataset. middle; Sub-step 4-3: Repeat sub-step 4-2 above, continuously providing new datasets until the last number in the new dataset is determined, and the last number and the numbers before it are stored in the new dataset. The final combination of numbers in each new dataset is the initial linear chain. Step 5 includes the following sub-steps: Sub-step 5-1: Read the first number in the preliminary linear chain, select the preliminary linear chain containing the number corresponding to the initial nuclide, and perform deduplication on it to obtain the complete linear chain; Sub-step 5-2: retrieve the preliminary linear chain that does not contain the corresponding number of the initial nuclide, extract the first number in the preliminary linear chain, delete the last feature symbol and the numbers following it in the first number to obtain a temporary number; Sub-step 5-3: Compare the temporary number with each number in the latest obtained complete linear chain, find the number in the complete linear chain that is the same as the temporary number, take the same number and all the numbers before it in the complete linear chain as a linear chain segment, and copy it; Sub-step 5-4: Copy the linear chain segment to the beginning of the initial linear chain, and perform deduplication on the new linear chain to obtain the complete linear chain; Sub-step 5-5, repeat sub-step 5-2, sub-step 5-3 and sub-step 5-4 until all the preliminary linear chains are processed and a complete linear chain is obtained; Sub-steps 5-6 involve obtaining the nuclear reaction chain by combining the corresponding numbers based on the order of the numbers in the complete linear chain.

2. The method for tracing activation source terms in nuclear reaction chain search based on feature symbol sorting according to claim 1, characterized in that, The deduplication process includes the following sub-steps: Step 1: Read and record the number of feature symbols for each number in the linear chain to be deduplicated, starting from the back and working backwards. In step 2, when the number of feature symbols in the last number is different from the number of feature symbols in the adjacent numbers before it, the linear chain is a complete linear chain. Step 3: When the number of feature symbols of the last number is the same as the number of feature symbols of its preceding adjacent number, record the value of the number of feature symbols. Filter out the numbers with the same number of feature symbols from back to front, count the number of such numbers as n, and then convert the linear chain to be deduplicated into n complete linear chains.

3. The method for tracing activation source terms in nuclear reaction chain search based on feature symbol sorting according to claim 2, characterized in that, In step 3, all the numbers before the last n numbers in the linear chain to be deduplicated are taken as the front segment numbers, and each of the n numbers is taken as a back segment number. The combination of the front segment number and any back segment number is a complete linear chain. The n back segment numbers are combined to form n complete linear chains.

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