Calculation method and device of nuclear power plant component source item, evaluation method and electronic equipment

Abstract

The invention discloses a calculation method and device for a component source item in a nuclear power plant loop, a radiation dose evaluation method and electronic equipment, and belongs to the technical field of nuclear power energy. The method comprises the steps that a source item network model of the nuclear power plant loop assembly is constructed, the source item network model comprises nodes and a connection relation between the nodes, the nodes are used for representing activity concentration of nuclides in the assemblies, and the transverse connection relation between the nodes is used for representing migration of the nuclides between the assemblies; the longitudinal connection relationship between the nodes is used for representing the decay of nuclides in the assembly; enumerating all paths from a starting node to a target node in the source item network model; calculating the nuclide activity concentration of a target node in each path; and summing the nuclide activity concentrations of the target nodes in all the paths to obtain a calculation result of the component source item. The method can solve the problem of low accuracy of a source item calculation result due to excessive simplification processing of a model in the prior art.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear power energy, and specifically relates to a method and device for calculating component source terms in a nuclear power plant loop, a method for evaluating radiation dose, and electronic equipment. Background Art

[0002] In the reactors of nuclear power plants, nuclear fuel undergoes a process called nuclear fission. In this process, a uranium nucleus is hit by a neutron and splits into two smaller nuclei, releasing energy, additional neutrons, and fission products. Fission products are radioactive materials produced by the splitting of nuclei, including various radioactive isotopes. At the same time, the high temperature and pressure environment inside the nuclear reactor, as well as the radiation, can cause corrosion of the materials inside the reactor (such as the fuel rod cladding and the metal parts of the coolant system). This corrosion process produces corrosion products, including metal ions and other chemicals.

[0003] Fission products and corrosion products will be contained in the coolant of the reactor. The inert gases Kr and Xe and other non-condensable hydrogen-containing waste gases will enter the waste gas treatment system through the degassing tower of the chemical and volume control system for treatment and then be discharged into the environment. The radioactive nuclides leaked from the equipment in the reactor building, auxiliary building, fuel building and conventional island building will enter the building ventilation system through evaporation and volatilization.

[0004] The fission products and corrosion products of the coolant enter the boron recovery system through the filling and discharge processes of the chemical and volume control systems; the process wastewater, chemical wastewater, and ground wastewater generated by the nuclear island are collected through the front storage tank of the radioactive waste liquid treatment system, and then these substances are removed through the filtration system, ion exchanger and chemical treatment methods, and finally enter the nuclear island waste liquid discharge system for monitoring and discharge after passing the test; the radioactive nuclides in the coolant will also enter the secondary loop system through the heat transfer pipes of the steam generator and be discharged into the environment along the conventional island discharge system.

[0005] Throughout the process, nuclear power plants are designed, operated, and regulated to ensure the safe management of radioactive materials and to prevent adverse effects on the environment and public health.

[0006] The main use of calculating source terms of equipment is in the field of nuclear energy, especially in nuclear safety analysis and radiation protection. Source terms represent the type, quantity and condition of radioactive materials released from nuclear reactors into the environment. For radiation protection, source terms are used to determine radiation levels in normal operation and accident conditions to ensure the safety of the public and the environment. For environmental impact assessment analysis, source terms are used to assess the potential impact of nuclear facilities on the surrounding environment, including water sources, soil and ecosystems. For nuclear facilities involved in operation, source term data helps design safer nuclear facilities and implement effective monitoring and control measures during operation. For waste management and disposal, source term calculations are used to assess the radioactivity levels and risks of nuclear waste treatment and final disposal.

[0007] The following technical difficulties are faced in the process of calculating the source term: the source term involves a variety of radioactive isotopes, each with a different half-life and chemical behavior, which makes the calculation complicated. The nuclide decay chain is a way to describe the decay process of radioactive nuclides, involving a series of continuous nuclear decay events until a stable state is reached. In this process, one radioactive nuclide decays into another nuclide, which may also be unstable and continues to decay, and so on until a stable nuclide is formed. At the same time, the system of nuclear power plants is too large and complex, and the migration pathways of radioactive nuclides need to be carefully identified and simplified by modeling, but they also have to pass through components in several loops. For example, radioactive waste liquid must be collected in the front storage tank, treated by the filtration system, ion exchanger and evaporator, and then enter the monitoring tank for monitoring and discharge.

[0008] Since the process of nuclide decay and migration is complex in actual situations, modeling is difficult and complicated. Therefore, the existing technologies have simplified the modeling process too much, such as only considering the process of nuclide decay without considering the migration of nuclides between multiple components (i.e., equipment); or only considering the migration of nuclides between multiple components without considering the influence of nuclide decay. Therefore, the current source term calculation results of components in nuclear power plant loops have the problem of low accuracy due to the excessive simplification of the model. Summary of the invention

[0009] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art and to provide a method and device for calculating the source terms of components in a nuclear power plant circuit, a method for evaluating radiation dose, and electronic equipment, which can construct a source term calculation network model that is more consistent with the actual situation, thereby improving the accuracy of the component source term calculation results.

[0010] In a first aspect, the present invention provides a method for calculating the source term of a component in a nuclear power plant loop, comprising: constructing a source term network model of the nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of nuclides m in the component, the horizontal connection relationship between the nodes is used to characterize the migration of nuclides m between components, and the vertical connection relationship between the nodes is used to characterize the decay of nuclides m in the component; enumerating all paths from the starting node to the target node in the source term network model; calculating the activity concentration of nuclides m at the target node in each path; and summing the activity concentrations of nuclides m at the target nodes in all paths to obtain the calculation result of the component source term.

[0011] Preferably, the calculation of the activity concentration of the nuclide m of the target node in each path specifically includes: for each path, sequentially determining whether there is a decay process between all adjacent nodes in the path; in response to a decay process between adjacent nodes, calculating the activity concentration of the nuclide m based on a first model, and transforming the first model based on a second model to obtain a decay result of the activity concentration of the nuclide m; in response to a migration process between adjacent nodes, calculating the activity concentration of the nuclide m based on a third model, and transforming the third model based on a fourth model to obtain a migration result of the activity concentration of the nuclide m; and calculating the activity concentration of the nuclide m of the target node in each path based on the decay result in the path and / or the migration result.

[0012] Preferably, the first model comprises:

[0013]

[0014] The second model includes:

[0015]

[0016] N(p)→MN(q1)-MN(q2),

[0017] The third model includes:

[0018]

[0019] The fourth model includes:

[0020]

[0021] N(p)→MN(q1)-MN(q2),

[0022] in, is the activity concentration of nuclide m in the nth component;

[0023] The fraction of nuclide m-1 that decays to nuclide m;

[0024] λ m-1 is the decay constant of nuclide m-1;

[0025] is the fraction of the nth component nuclide m entering from the inlet medium;

[0026] is the deposition coefficient of nuclide m in the nth component;

[0027] is the activity concentration of the nth component nuclide m-1;

[0028] → is the transformation of the solution of the equation;

[0029] g (n) is the input flow of component n;

[0030] n is the code of the current component,

[0031] p and N(p) satisfy the fifth model:

[0032]

[0033] MN(p)=M(p)N(p).

[0034] Preferably, the constructing of the source term network model of the nuclear power plant loop components specifically includes: constructing the source term network model of the components in the nuclear power plant loop according to the number of components involved in the nuclide m migration process and the nuclide decay chain.

[0035] In a second aspect, the present invention also provides a method for evaluating radiation dose, comprising: obtaining the emission activity of radioactive nuclides of target components in a nuclear power plant loop according to the calculation method of the component source term in a nuclear power plant loop described in the first aspect; judging whether the emission activity of the radioactive nuclides discharged into the environment exceeds a preset threshold; and evaluating the radiation dose impact of the radioactive nuclides on the public and organisms based on the judgment result.

[0036] In a third aspect, the present invention also provides a device for calculating the source term of a component in a nuclear power plant loop, comprising: a construction module, used to construct a source term network model of a nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of nuclides m in the component, the horizontal connection relationship between the nodes is used to characterize the migration of nuclides m between components, and the vertical connection relationship between the nodes is used to characterize the decay of nuclides m in the component. An enumeration module, connected to the construction module, is used to enumerate all paths from the starting node to the target node in the source term network model. A calculation module, connected to the enumeration module, is used to calculate the activity concentration of nuclides m at the target node in each path, and sums the activity concentrations of nuclides m at the target nodes in all paths to obtain the calculation result of the component source term.

[0037] Preferably, the calculation module includes a judgment unit and a calculation unit.

[0038] The judging unit is used to judge in sequence whether there is a decay process between all adjacent nodes in each path. The calculating unit is connected to the judging unit and is used to calculate the activity concentration of nuclide m based on the first model in response to the decay process between adjacent nodes, and transform the first model based on the second model to obtain the decay result of the activity concentration of nuclide m, and is also used to calculate the activity concentration of nuclide m based on the third model in response to the migration process between adjacent nodes, and transform the third model based on the fourth model to obtain the migration result of the activity concentration of nuclide m, and is used to calculate the activity concentration of nuclide m of the target node in each path according to the decay result and / or the migration result in the path.

[0039] In a fourth aspect, the present invention further provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for calculating the source terms of components in a nuclear power plant loop described in the first aspect or the method for evaluating the radiation dose described in the second aspect by executing the computer instructions.

[0040] The method and device for calculating the source term of a component in a nuclear power plant loop, the method for evaluating radiation dose, and the electronic device provided by the present invention construct a source term network model including the migration process of nuclides m between components and the decay process of nuclides m in the components, and then calculate the activity concentration of nuclides m in all paths to the target node in the source term network model, and then sum the activity concentration of nuclides m in all paths to obtain the calculation result of the component source term. Since the source term network model takes into account the migration process of nuclides between components and the decay process of nuclides in components, rather than only considering a single migration process or decay process, it is more consistent with the actual situation, so the accuracy of the component source term calculation result obtained according to the source term network model is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a flow chart of a method for calculating a component source term in a nuclear power plant circuit according to Embodiment 1 of the present invention;

[0042] Figure 2 A schematic diagram of a source term network model of embodiment 1 of the present invention;

[0043] Figure 3 A schematic diagram of a general mathematical model of a single node according to Embodiment 1 of the present invention;

[0044] Figure 4 Schematic diagram of another source term network model of embodiment 1 of the present invention;

[0045] Figure 5 is a schematic diagram of path 1 in embodiment 1 of the present invention;

[0046] Figure 6 is a schematic diagram of path 2 in embodiment 1 of the present invention;

[0047] Figure 7 is a schematic diagram of path 3 in embodiment 1 of the present invention;

[0048] Figure 8 A schematic diagram of a Pascal's triangle model according to Embodiment 2 of the present invention;

[0049] Fig. 9 This is a schematic diagram of the structure of a device for calculating the source terms of components in a nuclear power plant loop according to embodiment 4 of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the technical solution of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0051] It should be understood that the specific embodiments and drawings described herein are only used to explain the present invention rather than to limit the present invention.

[0052] It can be understood that, in the absence of conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other.

[0053] It can be understood that, for the convenience of description, the drawings of the present invention only show the parts related to the present invention, while the parts irrelevant to the present invention are not shown in the drawings.

[0054] It can be understood that each unit and module involved in the embodiments of the present invention may correspond to only one physical structure, or may be composed of multiple physical structures, or multiple units and modules may be integrated into one physical structure.

[0055] It can be understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of the present invention may occur in an order different from that marked in the drawings.

[0056] It is understood that the flowcharts and block diagrams of the present invention illustrate the possible architectures, functions, and operations of the systems, devices, equipment, and methods according to the various embodiments of the present invention. Each box in the flowchart or block diagram may represent a unit, module, program segment, or code, which contains executable instructions for implementing the specified functions. Moreover, each box or combination of boxes in the block diagram and flowchart may be implemented by a hardware-based system that implements the specified functions, or may be implemented by a combination of hardware and computer instructions.

[0057] It can be understood that the units and modules involved in the embodiments of the present invention can be implemented by software or hardware. For example, the units and modules can be located in a processor.

[0058] Embodiment 1:

[0059] like Figure 1 As shown, this embodiment provides a method for calculating the component source term in a nuclear power plant loop, which is applied to a nuclear power plant scenario, and is particularly suitable for the migration of radioactive nuclides between the entire process components of wastewater and waste gas in normal operation of a pressurized water reactor and expected operation event conditions, and in a scenario where decay is considered, the method for calculating the component source term in a nuclear power plant loop includes:

[0060] Step 101, constructing a source term network model of a nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of the nuclide m in the component, the horizontal connection relationship between the nodes is used to characterize the migration of the nuclide m between the components, and the vertical connection relationship between the nodes is used to characterize the decay of the nuclide m in the component.

[0061] In this embodiment, Figure 2 In the source term network model shown, A(i,j) is the activity concentration of the nuclide m at the node, i is the equipment code (i.e., the component code), j is the decaying sub-nucleus code, the horizontal arrows (i.e., the horizontal connection relationship between nodes) represent the migration of nuclide m between components in the loop, and the vertical arrows (i.e., the vertical connection relationship between nodes) represent the decay of nuclide m in a certain component. In other words, the migration of nuclides between components in the loop constitutes the horizontal "chain" of the source term network model; the decay of nuclides into sub-nuclides, and the decay of sub-nuclides into sub-nuclides, constitute the vertical "chain" of the source term network model.

[0062] The nodes in the source term network model are used to characterize the activity concentration of the nuclide m in the component. The derivation process is as follows: according to the working principles and characteristics of each component in the nuclear power plant loop, a single node model is established, and the general mathematical model of the radioactive nuclides in the mass exchange, absorption, retention and decay processes is considered. The differential equation is solved to give the source term of a single node.

[0063] For a single node, such as Figure 3 As shown, there are input flow, output flow, and circulation flow. Considering the decay, circulation removal, and emission of nuclides, the equivalent attenuation coefficient for nuclide m is:

[0064]

[0065] is the equivalent attenuation coefficient of the nth component nuclide m;

[0066] λ mis the decay constant of nuclide m;

[0067] G (n) is the flow rate of the circulating flow;

[0068] is the filter coefficient of the circulating flow of the nth component;

[0069] O (n) The flow rate of the output stream of the nth component;

[0070] V (n) is the volume of the nth component.

[0071] For the starting node, establish the differential equation:

[0072]

[0073] Boundary conditions: When t = 0,

[0074] Solve the differential equation:

[0075]

[0076] make:

[0077]

[0078] After finishing, we get:

[0079]

[0080] in, is the activity concentration of the first component nuclide m;

[0081] g (1) is the input flow of the first component;

[0082] is the share of the first component nuclide m entering from the inlet medium;

[0083] is the activity concentration of nuclide m in the input flow.

[0084] In order to normalize the calculation of node source items in the source item network model, the following transformation model (ie, the fifth model) is set. The fifth model is the basis for modeling the entire source item network model.

[0085] make:

[0086]

[0087] MN(p)=M(p)N(p)

[0088] Transform the fifth model to obtain A(1,1) as above, and we have:

[0089]

[0090] Let a(i,j) be the i-th component and consider the activity concentration of the j-th generation nuclide, then:

[0091]

[0092] Step 102, enumerate all paths from the start node to the target node in the source network model.

[0093] In this embodiment, the radioactive waste liquid is collected through the pre-storage tank, treated by the desalter, and then enters the monitoring tank for decay monitoring. The activity concentration of the nuclide m in the monitoring tank needs to be obtained as an example to construct a source term network model. The source term network model involves the following three components: pre-storage tank, desalter, and monitoring tank. At the same time, considering the parent nucleus and the first generation daughter in the decay chain, a 3×2 source term network model can be established, such as Figure 4 As shown, the goal is to find the activity concentration of nuclide m a(3,2), then node a(3,2) is the target node. Enumerate all paths from the starting node to the target node a(3,2), such as Figure 5 , Figure 6 , Figure 7 As shown, there are three paths in total, namely:

[0094] Path 1: a(1,1)→a(2,1)→a(3,1)→a(3,2);

[0095] Path 2: a(1,1)→a(2,1)→a(2,2)→a(3,2);

[0096] Path 3: a(1,1)→a(1,2)→a(2,2)→a(3,2).

[0097] Step 103, calculating the activity concentration of the nuclide m at the target node in each path.

[0098] In this embodiment, the activity concentration of the nuclide m of the target node in each path is calculated, and for each path, it is sequentially determined whether there is a decay process between all adjacent nodes in the path; in response to the decay process between adjacent nodes, the activity concentration of the nuclide m is calculated based on the first model, and the first model is transformed based on the second model to obtain the decay result of the activity concentration of the nuclide m; in response to the migration process between adjacent nodes, the activity concentration of the nuclide m is calculated based on the third model, and the third model is transformed based on the fourth model to obtain the migration result of the activity concentration of the nuclide m; based on the decay result in the path, and / or the migration result, the activity concentration of the nuclide m of the target node in each path is calculated.

[0099] The first model includes:

[0100]

[0101] The second model includes:

[0102]

[0103] N(p)→MN(q1)-MN(q2),

[0104] The third model includes:

[0105]

[0106] The fourth model includes:

[0107]

[0108] N(p)→MN(q1)-MN(q2),

[0109] in, is the activity concentration of nuclide m in the nth component;

[0110] The fraction of nuclide m-1 that decays to nuclide m;

[0111] λ m-1 is the decay constant of nuclide m-1;

[0112] is the fraction of the nth component nuclide m entering from the inlet medium;

[0113] is the deposition coefficient of nuclide m in the nth component;

[0114] is the activity concentration of the nth component nuclide m-1;

[0115] → is the transformation of the solution of the equation;

[0116] g (n) is the input flow of component n;

[0117] n is the code of the current component,

[0118] p and N(p) satisfy the fifth model:

[0119]

[0120] MN(p)=M(p)N(p).

[0121] In this embodiment, if all components are used to establish a differential equation system and the calculation of the decay chain is taken into account at the same time, the solution of the differential equation system will be extremely complicated. The network model formed by the decay "chain" and the migration "chain" proposed in the present invention provides an implementable solution to improve the calculation efficiency: in the decay process, the first model is transformed based on the second model to obtain the decay result; in the migration process, the third model is transformed based on the fourth model to obtain the migration result, so that the source term network model established based on this embodiment can quickly provide a solution for nuclide m. The following is an example of calculating the activity concentration of nuclide m at the target node in three paths:

[0122] (1) For path 1: a(1,1)→a(2,1)→a(3,1)→a(3,2).

[0123]

[0124] Migrate to a(2,1), based on the third model:

[0125]

[0126] Based on the fourth model:

[0127] Based on the fourth model, we have:

[0128]

[0129] Migrate to a(3,1), based on the third model:

[0130]

[0131] For a(2,1) and Based on the fourth model:

[0132]

[0133] The transformations based on the fourth model are:

[0134]

[0135]

[0136] Decaying to a(3,2), we have:

[0137]

[0138] In order to calculate Convert m in the formula a(3,1) to m-1, where nuclide m-1 is the parent nuclide of nuclide m:

[0139]

[0140] Based on the second model:

[0141]

[0142] Transform based on the second model, that is, in a m The a in the formula m-1 Substituting the above 4 substitutions into , we get:

[0143]

[0144]

[0145] (2) For path 2: a(1,1)→a(2,1)→a(2,2)→a(3,2).

[0146]

[0147] Migrate to a(2,1), as in step (1):

[0148]

[0149] Decaying to a(2,2), we have:

[0150]

[0151] Convert m in the formula a(2,1) to m-1:

[0152]

[0153] Based on the second model:

[0154]

[0155] The transformations based on the second model are:

[0156]

[0157] Migrate to a(3,2), based on the third model:

[0158]

[0159] Based on the fourth model:

[0160]

[0161] Transform based on the fourth model, that is, substitute the above 4 replacements:

[0162]

[0163] (3) For path 3: a(1,1)→a(1,2)→a(2,2)→a(3,2).

[0164]

[0165] Decays to a(1,2):

[0166]

[0167] Based on the second model:

[0168]

[0169] The transformations based on the second model are:

[0170]

[0171] Migrate to A(2,2), based on the third model:

[0172]

[0174] Based on the fourth model:

[0175]

[0176] The transformations based on the fourth model are:

[0177]

[0178] Migrate to a(3,2), based on the third model:

[0179]

[0180] Based on the fourth model:

[0181]

[0182] The transformations based on the fourth model are:

[0183]

[0184]

[0185] Step 104, summing up the activity concentrations of nuclides m at the target nodes in all paths to obtain the calculation results of the component source terms.

[0186] In this embodiment, the sum of the activity concentrations of the above three paths is:

[0187]

[0188] At this point, the activity concentration of a(3,2) has been solved. It can be seen that as the number of nodes in the source network model increases, the number of paths will increase. For the target node a(i,j), the number of paths is: (i-1)×(j-1)+1.

[0189] Optionally, constructing the source term network model of the nuclear power plant loop components specifically includes: constructing the source term network model of the components in the nuclear power plant loop according to the number of components involved in the nuclide m migration process and the nuclide decay chain.

[0190] In this embodiment, the number of horizontal nodes of the source term network model is the number of components involved in the migration process of nuclide m, and the number of vertical nodes of the source term network model is related to the nuclide decay chain. For example, if a 4×3 source term network model is established, it means that the number of components involved in the migration process of nuclide m is 4, and the nuclide decay chain includes a parent nucleus, a first-generation daughter nucleus, and a second-generation daughter nucleus.

[0191] The method for calculating the source term of the components in the nuclear power plant loop provided in this embodiment constructs a source term network model including the migration process of the nuclide m between components and the decay process of the nuclide m in the components, and then calculates the activity concentration of the nuclide m in all paths from the source term network model to the target node, and then sums the activity concentration of the nuclide m in all paths to obtain the calculation result of the source term of the target component. Since the source term network model takes into account the migration process of the nuclide between components and the decay process of the nuclide in the component, rather than only considering a single migration process or decay process, it is more consistent with the actual situation, so the calculation result of the component source term obtained according to the source term network model is more accurate. Furthermore, in the decay process between nodes, the first model is transformed based on the second model to obtain the decay result; in the migration process between nodes, the third model is transformed based on the fourth model to obtain the migration result, which can simplify the calculation process and improve the calculation efficiency. In addition, the source network model can be used to calculate the migration, accumulation, decay and emission of radionuclides in components in circuits such as wastewater storage tanks, spent fuel pools, exhaust gas storage boxes, filters, evaporators, desalters, etc., and has a wide range of applications.

[0192] Embodiment 2:

[0193] This embodiment provides a method for calculating a component source term in a nuclear power plant circuit, including:

[0194] Step 201, constructing a source term network model of a nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of the nuclide m in the component, the horizontal connection relationship between the nodes is used to characterize the migration of the nuclide m between the components, and the vertical connection relationship between the nodes is used to characterize the decay of the nuclide m in the component.

[0195] In this embodiment, only the nuclide migration process is considered, and the situation of nuclide decay daughters is not considered. Therefore, the constructed source term network model only includes nodes and the horizontal connection relationship between nodes.

[0196] Step 202, enumerate all paths from the start node to the target node in the source network model.

[0197] In this embodiment, there is only one path: a(1,1)→a(2,1)→a(3,1)→a(4,1).

[0198] Step 203, calculating the activity concentration of the nuclide m at the target node in each path.

[0199] Specifically, calculating the activity concentration of the nuclide m of the target node in each path includes: for the path that only includes the migration process, constructing a Pascal's triangle model, wherein each element in the Pascal's triangle model is an ordered pair, the first value in the ordered pair is the current layer number of the Pascal's triangle model, and the second value is obtained by disassembling the ordered pair of the previous layer, and the total number of layers is consistent with the number of components involved in the target node; calculating the activity concentration of the nuclide m of the target node in each path according to the ordered pairs in the Pascal's triangle model.

[0200] In this embodiment, the Pascal's triangle model refers to a model similar to the Pascal's triangle. Figure 8 The Pascal's triangle model shown in the figure, since the number of components involved in the migration process is 4, the number of layers of the model is 4. For example, for the ordered pairs (4,3) and (4,1), the first value in the ordered pair is the current layer of the Pascal's triangle model, which is the 4th layer, and the second value 3 and 1 are obtained by disassembling the ordered pair (3,1) of the previous layer. According to the ordered pairs in the Pascal's triangle model and the third model and the fourth model in Example 1, the activity concentration of the nuclide m of the target node in the path is calculated. Example: According to the ordered pairs in the Pascal's triangle model and the third model and the fourth model in Example 1, the activity concentration of the nuclide m of the target node in the path is intuitively listed:

[0201]

[0202] It is easy to see from the formula of A(4,1) that the values ​​of p, q1, and q2 are related to ordered pairs similar to the Pascal's triangle model.

[0203] Step 204, summing up the activity concentrations of nuclides m at the target nodes in all paths to obtain the calculation result of the component source term.

[0204] In this embodiment, since there is only one path, no calculation is required.

[0205] The solutions to restore a(4,1) are:

[0206]

[0207] The solution is complete.

[0208] From the restored solution, it can be seen that after the fourth model of this embodiment is transformed, the calculation result obtained by the transformation is restored, and finally a model expression that conforms to the actual physical meaning is obtained, which shows that the transformation process has the beneficial effect of simplifying the calculation process. Similarly, the transformation process based on the second model also has the beneficial effect of simplifying the calculation process. In addition, this embodiment further improves the calculation efficiency by constructing a model similar to the Yang Hui triangle and intuitively providing a solution for the activity concentration based on the Yang Hui triangle model.

[0209] The method for calculating the source terms of components in a nuclear power plant circuit provided in this embodiment provides a fast solution to the source term calculation that only considers the migration process in the prior art, which can improve the calculation efficiency.

[0210] Embodiment 3:

[0211] This embodiment provides a method for evaluating radiation dose, including:

[0212] Step 301: Obtain the radionuclide emission activity of a target component in a nuclear power plant loop according to the calculation method of the component source term in a nuclear power plant loop of Example 1 or Example 2.

[0213] Step 302: determine whether the emission activity of the radioactive nuclides discharged into the environment exceeds a preset threshold.

[0214] Step 303, evaluating the radiation dose impact of the radioactive nuclides on the public and organisms based on the judgment result.

[0215] Embodiment 4:

[0216] like Fig. 9 As shown, this embodiment provides a device for calculating the source term of a component in a nuclear power plant loop, including:

[0217] Construction module 41 is used to construct a source term network model of a nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of the nuclide m in the component, the horizontal connection relationship between the nodes is used to characterize the migration of the nuclide m between the components, and the vertical connection relationship between the nodes is used to characterize the decay of the nuclide m in the component.

[0218] The enumeration module 42 is connected to the construction module 41 and is used to enumerate all paths from the start node to the target node in the source network model.

[0219] The calculation module 43 is connected to the enumeration module 42 and is used to calculate the activity concentration of the nuclide m of the target node in each path, and sum the activity concentrations of the nuclide m of the target nodes in all paths to obtain the calculation result of the component source term.

[0220] Optionally, the calculation module includes a judgment unit and a calculation unit.

[0221] The judging unit is used to judge, for each path, whether there is a decay process between all adjacent nodes in the path in sequence.

[0222] The calculation unit is connected to the judgment unit, and is used for calculating the activity concentration of the nuclide m based on the first model in response to a decay process between adjacent nodes, and transforming the first model based on the second model to obtain a decay result of the activity concentration of the nuclide m; and is also used for calculating the activity concentration of the nuclide m based on the third model in response to a migration process between adjacent nodes, and transforming the third model based on the fourth model to obtain a migration result of the activity concentration of the nuclide m; and, is used to calculate the activity concentration of the nuclide m of the target node in each path according to the decay result and / or the migration result in the path.

[0223] The first model includes:

[0224]

[0225] The second model includes:

[0226]

[0227] N(p)→MN(q1)-MN(q2),

[0228] The third model includes:

[0229]

[0230] The fourth model includes:

[0231]

[0232] N(p)→MN(q1)-MN(q2),

[0233] in, is the activity concentration of nuclide m in the nth component;

[0234] The fraction of nuclide m-1 that decays to nuclide m;

[0235] λ m-1 is the decay constant of nuclide m-1;

[0236] is the fraction of the nth component nuclide m entering from the inlet medium;

[0237] is the deposition coefficient of nuclide m in the nth component;

[0238] is the activity concentration of the nth component nuclide m-1;

[0239] → is the transformation of the solution of the equation;

[0240] g (n) is the input flow of component n;

[0241] n is the code of the current component,

[0242] p and N(p) satisfy the fifth model:

[0243]

[0244] MN(p)=M(p)N(p).

[0245] Optionally, the construction module is used to construct a source term network model of components in a nuclear power plant loop according to the number of components involved in the nuclide m migration process and the nuclide decay chain.

[0246] The calculation device for the source term of components in the nuclear power plant loop provided in this embodiment can be used to calculate the activity accumulation and emission of radioactive nuclides in components in the loops such as wastewater storage tanks, spent fuel pools, waste gas storage boxes, filters, evaporators, desalters, etc. of nuclear power units under normal operation and expected operation event conditions. It is used to establish a general network model based on the process characteristics of nuclear power plants, which can simulate the entire process of nuclear power plant wastewater or waste gas, consider the migration, absorption, retention and decay process of radioactive nuclides between equipment, and quickly give a group of activity balance differential equations. The calculation results of the calculation device can be widely used in radiation shielding and emission source term calculations.

[0247] Embodiment 5:

[0248] This embodiment provides an electronic device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for calculating the source term of components in a nuclear power plant loop described in Example 1 or Example 2 or the method for evaluating the radiation dose described in Example 3 by executing the computer instructions.

[0249] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for calculating component source terms in a nuclear power plant circuit, characterized in that: include: Constructing a source term network model of a nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of nuclides m in the components, the lateral connection relationships between the nodes are used to characterize the migration of nuclides m between the components, and the longitudinal connection relationships between the nodes are used to characterize the decay of nuclides m in the components; Enumerate all paths from the starting node to the target node in the source network model; Calculate the activity concentration of nuclide m at the target node in each path; The activity concentrations of nuclides m at the target nodes in all paths are summed to obtain the calculation results of the component source terms.

2. The method according to claim 1, characterized in that The calculation of the nuclide m activity concentration of the target node in each path specifically includes: For each path, determine in sequence whether all adjacent nodes in the path are in a decay process; In response to a decay process between adjacent nodes, the activity concentration of nuclide m is calculated based on a first model, and the first model is transformed based on a second model to obtain a decay result of the activity concentration of nuclide m; In response to the migration process between adjacent nodes, the activity concentration of the nuclide m is calculated based on the third model, and the third model is transformed based on the fourth model to obtain a migration result of the activity concentration of the nuclide m; The activity concentration of the nuclide m at the target node in each path is calculated according to the decay results and / or migration results in the path.

3. The method according to claim 2, characterized in that The first model includes: The second model includes: N(p)→MN(q1)-MN(q2), the third model includes: The fourth model includes: N(p)→MN(q1)-MN(q2), where is the activity concentration of nuclide m in the nth component; The fraction of nuclide m-1 that decays to nuclide m; λ m*1 is the decay constant of nuclide m-1; is the fraction of nuclide m of the nth component entering from the inlet medium; is the deposition coefficient of nuclide m in the nth component; is the activity concentration of the nth component nuclide m-1; → is the transformation of the solution of the equation; g (n) is the input flow of component n; n is the code of the current component, p and N(p) satisfy the fifth model: MN(p)=M(p)N(p).

4. The method according to claim 1, characterized in that: The source term network model of the nuclear power plant loop components is constructed, specifically including: According to the number of components involved in the migration process of nuclide m and the nuclide decay chain, a source term network model of the components in the nuclear power plant loop is constructed.

5. A method for evaluating radiation dose, characterized in that: include: Obtaining the radionuclide emission activity of the target component in the nuclear power plant loop according to the calculation method of the component source term in the nuclear power plant loop according to any one of claims 1 to 4; Determining whether the emission activity of the radionuclides discharged into the environment exceeds a preset threshold; Based on the judgment results, the radiation dose impact of radionuclides on the public and organisms is evaluated.

6. A device for calculating the source term of a component in a nuclear power plant loop, characterized in that: include: A construction module is used to construct a source term network model of a nuclear power plant loop component, wherein the source term network model includes nodes and connection relationships between nodes, the nodes are used to characterize the activity concentration of nuclides m in the components, the horizontal connection relationships between nodes are used to characterize the migration of nuclides m between components, and the vertical connection relationships between nodes are used to characterize the decay of nuclides m in the components, An enumeration module, connected to the construction module, is used to enumerate all paths from the starting node to the target node in the source network model, The calculation module is connected to the enumeration module and is used to calculate the activity concentration of the nuclide m of the target node in each path, and sum the activity concentration of the nuclide m of the target nodes in all paths to obtain the calculation result of the component source term.

7. The device according to claim 6, characterized in that The calculation module includes a judgment unit and a calculation unit. The judgment unit is used to judge, for each path, whether there is a decay process between all adjacent nodes in the path in sequence. a calculation unit connected to the judgment unit, for responding to a decay process between adjacent nodes, calculating the activity concentration of nuclide m based on the first model, and transforming the first model based on the second model to obtain a decay result of the activity concentration of nuclide m; and for responding to a migration process between adjacent nodes, calculating the activity concentration of nuclide m based on the third model, and transforming the third model based on the fourth model to obtain a migration result of the activity concentration of nuclide m. And, it is used to calculate the activity concentration of the nuclide m of the target node in each path according to the decay result and / or the migration result in the path.

8. An electronic device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for calculating the source term of a component in a nuclear power plant circuit according to any one of claims 1 to 4 or the method for evaluating the radiation dose according to claim 5 by executing the computer instructions.

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