Method, system and equipment for detecting foreign matter introduction time of nuclear power plant and storage medium
By detecting the detector's results and distance, and combining the radioactivity of the activated isotope with the neutron flux, the introduction time of foreign objects can be calculated, solving the problem of the difficulty in detecting the introduction time of foreign objects in the primary loop of nuclear power plants and improving radiation safety.
Patent Information
- Application Number
- CN202511125683.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-11-07
AI Technical Summary
Existing technologies cannot effectively detect the introduction time of foreign objects in the primary loop of nuclear power plants, making it difficult to accurately determine the source of foreign objects and affecting radiation safety.
By obtaining the detector's detection results and detection distance, the radioactivity of the activated isotope is determined. Combined with the foreign object's property information and neutron flux, the introduction time of the foreign object is calculated.
It enables accurate quantification of the introduction time of foreign objects in the primary loop of nuclear power plants, provides a basis for judging the source of foreign objects, and improves radiation safety.
Smart Images
Figure CN120908846A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of physical testing, in particular to a method, system and device for detecting the introduction time of foreign matter in a nuclear power plant and a storage medium. BACKGROUND
[0002] The primary loop of a nuclear power plant is a loop to which the reactor coolant belongs. Since the primary loop fluid is in direct contact with the nuclear fuel, it has high radioactivity. Therefore, the structural integrity of the primary loop is directly related to the radiation safety of the nuclear power plant. When foreign matter exists in the primary loop, the foreign matter can cause aging phenomena such as vibration and wear of the corresponding equipment components, and in severe cases, can cause damage to the integrity of the primary loop pressure boundary, and the diffusion of radioactive fluid to the secondary loop or even the environment. At present, since multiple auxiliary systems serve the primary loop main system, foreign matter can be introduced into the primary loop main loop through multiple pipeline equipment, which leads to the fact that the primary loop is currently limited by complex working conditions and cannot confirm the source of internal foreign matter.
[0003] Therefore, it is necessary to provide a method, system, device and storage medium for detecting the introduction time of foreign matter in a nuclear power plant to improve the above problems. SUMMARY
[0004] The purpose of the present disclosure is to provide a method, system, device and storage medium for detecting the introduction time of foreign matter in a nuclear power plant to solve the technical problem that the current detection method is limited by the complex pipeline working conditions of the primary loop and it is difficult to accurately detect the introduction time of internal foreign matter in the primary loop.
[0005] To achieve the above object and other related objects, in a first aspect, the present disclosure provides a method for detecting the introduction time of foreign matter in the primary loop of a nuclear power plant, which comprises the following steps: obtaining the detection result of the detector for the foreign matter and the detection distance between the detector and the foreign matter; determining the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance; obtaining the attribute information of the foreign matter and the neutron flux of the environment in which the foreign matter is located; the attribute information includes the mass, natural element content, activation cross section of each type of natural element and decay constant of the activated isotope corresponding to each type of natural element of the foreign matter; determining the introduction time of the foreign matter based on the neutron flux, the attribute information and the radioactivity of the activated isotope.
[0006] In a second aspect, the present disclosure provides a detection system for detecting the introduction time of foreign matter in the primary loop of a nuclear power plant, which comprises: a detection information acquisition module for acquiring the detection result of the detector for the foreign matter and the detection distance between the detector and the foreign matter; a radioactivity determination module configured to determine a radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance; a foreign matter information acquisition module configured to acquire attribute information of the foreign matter and a neutron flux of an environment where the foreign matter is located, the attribute information including a mass of the foreign matter, a natural element content, an activation cross section of each type of the natural element, and a decay constant of an activated isotope corresponding to each type of the natural element; a time of introduction determination module configured to determine the time of introduction of the foreign matter based on the neutron flux, the attribute information, and the radioactivity of the activated isotope.
[0007] In a third aspect, the present disclosure provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method of any one of the examples when executing the computer program.
[0008] In a fourth aspect, the present disclosure provides a computer-readable storage medium, which stores a computer program, and the computer program is executable on a processor to implement the steps of the method of any one of the examples.
[0009] The detection method for the time of introduction of a foreign matter in a primary loop of a nuclear power plant provided by the present disclosure restores the radioactivity of an activated isotope in the foreign matter based on a detection result of the foreign matter by a detector and a detection distance; determines a relationship between the radioactivity of the activated isotope perceived by the detection result and the time of introduction of the foreign matter according to attribute information of the foreign matter and a neutron flux of radiation in the environment of the primary loop; and finally determines the time of introduction of the foreign matter in the primary loop based on the radioactivity of the activated isotope and the relationship between the radioactivity of the activated isotope and the time of introduction. The detection method uses the characteristic that the fluid in the primary loop is radioactive, determines the time of introduction of the foreign matter based on the radioactivity intensity and attribute information of the foreign matter after the foreign matter existing in the primary loop is measured, and thus provides a basis for judging the source of the foreign matter. BRIEF DESCRIPTION OF DRAWINGS
[0010] The features and advantages of the present disclosure will be better understood by referring to the accompanying drawings, which are presented as exemplary and not limiting, in which: Figure 1 a flowchart showing a foreign matter time of introduction detection method in an embodiment of the present disclosure; Figure 2 a flowchart showing step S4 in an embodiment of the present disclosure; Figure 3 a flowchart showing step S41 in an embodiment of the present disclosure; Figure 4A structural block diagram of a detection system in an embodiment of the present disclosure is shown. Figure 5 A structural block diagram of a computer device in an embodiment of the present disclosure is shown.
[0011] Element number explanation: 10, detection system; 11, probe information acquisition module; 12, radioactivity determination module; 13, foreign matter information acquisition module; 14, introduction time determination module. DETAILED DESCRIPTION
[0012] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present disclosure.
[0013] Please refer to Figures 1 to 5 It should be noted that the diagrams provided in the present embodiment only schematically illustrate the basic concept of the present disclosure, and the diagrams only show the components related to the present disclosure, rather than the number, shape and size of the components in actual implementation. The actual implementation of each component may be randomly changed in terms of shape, number and proportion, and the layout pattern of the components may be more complex.
[0014] Please refer to Figure 1 In a first aspect, the present disclosure provides a detection method for foreign matter introduction time in a primary loop of a nuclear power plant, and the detection method comprises the following steps: Step S1: obtaining a detection result of a probe for foreign matter and a detection distance between the probe and the foreign matter.
[0015] In step S1, an effective detection result of a probe for foreign matter in a primary loop and a detection distance of the probe from the foreign matter when the detection result is measured are obtained. The effective detection result is a stable and obviously stronger radioactivity intensity than environmental noise measured by the probe. The detection result may be, for example, a dose rate or specific energy release rate measured for a gamma point source, or a dose rate measured for a beta point source. The dose rate measured for a gamma point source may be equivalent to the specific energy release rate. It should be noted that the measurement method of the detection result is not limited in the present disclosure, and the detection result may be obtained by detecting the foreign matter taken out from the primary loop by the probe.
[0016] Step S2: determining a radioactivity of an activated isotope corresponding to the detection result based on the detection result and the detection distance.
[0017] In some embodiments, when the detection result is the specific energy release rate measured for a gamma point source, the radioactivity of the activated isotope corresponding to the detection result is determined according to a formula (1) relationship based on the detection result and the detection distance, and the formula (1) relationship is as follows: (1) wherein, K is the measured specific energy release rate, in units of Sv / s or Gy / s; G is a specific energy release rate constant, in units of Gy·m 2 / (s·Bq) or Gy·m 2 / (h·Bq), determined by the gamma ray energy, emission probability, and mass-energy transfer coefficient of the nuclide, and the type of medium (default air); A is the radioactivity of the activated isotope corresponding to the detection result, in units of Bq; r is the detection distance of the detector relative to the measured foreign matter, in units of m.
[0018] In other embodiments, when the detection result is the specific energy release rate measured for a gamma point source, the radioactivity of the activated isotope corresponding to the detection result can also be determined according to a formula (2) relationship based on the detection result and the detection distance, and the formula (2) relationship is as follows: (2) wherein, K is the measured specific energy release rate, in units of Sv / s or Gy / s; A is the radioactivity of the activated isotope corresponding to the detection result, in units of Bq; is the photon fluence rate of the activated isotope, is the number of photons emitted per decay of the activated isotope, in units of / (cm 2 ·s); E is the average energy of particles of the activated isotope, in units of MeV; is the mass-energy absorption coefficient, in units of cm 2 / g; r is the detection distance of the detector relative to the measured foreign matter.
[0019] In yet other embodiments, when the detection result is the dose rate measured for a beta point source, the radioactivity of the activated isotope corresponding to the detection result can be determined according to a formula (3) relationship based on the detection result and the detection distance, and the formula (3) relationship is as follows: (3) wherein, K is the measured dose rate, in units of Sv / s or Gy / s; A is the radioactivity of the activated isotope corresponding to the detection result, in units of Bq; EE is the average energy of the particle of the activation isotope, in MeV; is the mass-energy absorption coefficient, in cm 2 / g; r is the detection distance of the detector relative to the detected foreign object.
[0020] Step S3, obtaining attribute information of the foreign object and neutron flux of the environment where the foreign object is located.
[0021] In step S3, the attribute information of the foreign object includes the mass of the foreign object, the natural element content, the activation cross section of each type of natural element, and the decay constant of the activation isotope corresponding to each type of natural element. Among them, the mass of the foreign object can be measured after the foreign object is taken out, and the natural element content of the foreign object is measured by EDS energy spectrum, mass spectrum and the like.
[0022] In step S3, the neutron flux in the environment of the loop where the foreign object is located and the attribute information of the foreign object are measured, so as to determine the number of radioactive activation isotopes generated by the target nuclei of the natural elements in the foreign object under the radiation of the reactor core in the subsequent step.
[0023] Step S4, determining the introduction time of the foreign object based on the neutron flux, the attribute information and the radioactivity of the activation isotope.
[0024] As shown in Figure 2 , in some embodiments, step S4 includes the following steps: Step S41, determining the relationship between the radioactivity of the activation isotope in the foreign object and the introduction time based on the neutron flux and the attribute information. As shown in Figure 3 , in some embodiments, step S41 includes the following steps: S411, determining the number of target nuclei of the natural element corresponding to the activation isotope based on the mass and natural element content of the foreign object.
[0025] In step S411, based on the mass and natural element content of the foreign object, the number of target nuclei of the natural element corresponding to the activation isotope perceived by the detector is determined according to formula (4) relationship, and formula (4) relationship is as follows: (4) wherein, m is the mass of the foreign object, is the natural element content of the foreign object that is converted into radioactive activation isotope, M i is the molar mass of the natural element that is converted into radioactive activation isotope, n i is the number of target nuclei of the above natural element, N A is Avogadro's constant.
[0026] S412, determining the relationship between the radioactivity of the activated isotope in the foreign matter and the introduction time based on the neutron flux, the target nucleus number of the activated isotope corresponding natural element, the activation cross section of the natural element and the decay constant of the activated isotope.
[0027] In step S412, the number of radioactive activated isotopes formed by the natural element target nucleus in the foreign matter under the radiation of the primary loop environment is determined based on the neutron flux in the primary loop environment, the target nucleus number of the natural element in the foreign matter and the activation cross section of the natural element. Specifically, the number of radioactive activated isotopes formed by the natural element target nucleus in the foreign matter under the radiation of the primary loop environment is determined according to the formula (5) relationship as follows: (5) Wherein, N i The number of activated isotopes in the foreign matter detected by the detector; The activation cross section of the activated isotope corresponding natural element, unit: cm 2 ; The neutron flux in the environment, obtained by the neutron flux detection for the reactor core, unit: n / (cm 2 •s).
[0028] Then, the relationship between the radioactivity of the activated isotope in the foreign matter and the introduction time is determined according to the formula (6) relationship based on the number of activated isotopes and the decay constant of the activated isotope, and the formula (6) relationship is as follows: (6) Wherein, N i The number of activated isotopes in the foreign matter detected by the detector; The decay constant of the activated isotope, ln2 / T 1 / 2 , T 1 / 2 The half-life of the activated isotope; t The decay time of the radiation radioactive rays of the activated isotope, that is, the introduction time of the foreign matter into the primary loop.
[0029] Step S42, determining the introduction time of the foreign matter based on the radioactivity of the activated isotope and the relationship between the radioactivity of the activated isotope and the introduction time.
[0030] In step S42, the radioactivity of the activated isotope in the foreign matter determined in step S2 is substituted into the formula (6) relationship obtained in step S41 to determine the introduction time of the foreign matter into the primary loop.
[0031] The introduction time of the foreign matter is determined by detection, and the source of the foreign matter is preliminarily judged in combination with the operation condition of the loop opening in the introduction time. For example, if the introduction time is less than one overhaul period (for example, 1.5 years), it is considered that the foreign matter is introduced from outside during the overhaul process; if the introduction time is greater than one overhaul period, it is considered that the foreign matter is probably from inside the primary loop or introduced from outside before one overhaul period.
[0032] The technical solutions of the present application are described in detail below through an example. Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by conventional methods in the art.
[0033] In this example, for the iron piece with a mass of 0.01 g, the dose rate a measured by the detector at a detection distance of 1 cm is 2 μSv / h, which can be converted into a specific kerma rate of 5.55×10 -10 Sv / s, and the neutron flux of the core environment is 4×10 13 n cm 2 s The introduction time of the iron piece is determined according to the detection method of the present disclosure, specifically including the following steps: First step, for the iron piece, it is determined that the iron piece contains natural elements Fe54, Fe56, Fe57 and Fe58, and the element contents of the natural elements Fe54, Fe56, Fe57 and Fe58 are 5.8%, 91.72%, 2.1% and 0.28% respectively. Among them, Fe54 becomes Fe55 after absorbing neutrons, which has radioactivity, and the half-life is 2.737 years, that is, 86314032 s; Fe58 becomes Fe59 after absorbing neutrons, which has radioactivity, and the half-life is 44.5 days, that is, 3844800 s. Since the detector can only obtain the radiation intensity of γ rays, and no γ rays are released in the process of Fe54 generating Fe55 by neutron capture, and X rays are released, and γ rays are released in the process of Fe58 generating Fe59 by neutron capture, it can be determined that the γ ray intensity radiated when the natural element Fe58 is converted into Fe59 is measured by the detector for the iron piece.
[0034] Second step, based on the detection result and the detection distance, the radioactivity of Fe59 in the iron piece is calculated according to formula (1), specifically A Fe59 =K×r 2 / Γ=(5.55×10 -10 Sv / s)×(0.01 2 m 2 )÷(4.4×10 -17 Gy·m 2 / (s·Bq))=1261.36Bq.
[0035] The third step is to determine the number of Fe58 atoms in the iron sheet based on the mass of the iron sheet and the content of natural elements. Specifically, N Fe58 = (0.28% x 0.01g / 55.845g / mol) x N A ≈ 3.02 x 10 17 atoms.
[0036] The fourth step is to determine the radioactivity A Fe59 of Fe59 based on the environmental neutron flux, the number of Fe58 atoms in the iron sheet, the activation cross section of Fe58, and the decay constant λ of Fe59 according to the relationship of formula (5) and formula (6). Specifically, A Fe59 = N Fe58 x σ 58 x φ x (1-e --λt ) = 3.02 x 10 17 x 1.3 x 10 -28 x 4 x 10 13 x (1-e -1.8×(10^-7)×t ) = 1.57 x 10 4 x (1-e -1.8×(10^-7)×t ).
[0037] The fifth step is to substitute the radioactivity of Fe59 measured in the second step into the relationship between the radioactivity A Fe59 of Fe59 and the introduction time t in the fourth step to obtain the introduction time t of the iron sheet as 9016156.556s, i.e. 104 days.
[0038] In summary, the detection method utilizes the radioactivity of the fluid in the primary loop. After detecting the foreign matter existing in the primary loop, the introduction time of the foreign matter is determined based on the radioactivity intensity and attribute information of the foreign matter, thereby providing a basis for judging the source of the foreign matter.
[0039] In a second aspect, the present application provides a detection system 10 for the introduction time of foreign matter in the primary loop of a nuclear power plant. The detection system 10 corresponds to the detection method in the above-mentioned embodiments.
[0040] As shown in Figure 4 , the detection system 10 includes a detection information acquisition module 11, a radioactivity determination module 12, a foreign matter information acquisition module 13, and an introduction time determination module 14. The functions of each module are described in detail as follows: The detection information acquisition module 11 is configured to acquire the detection result of the detector on the foreign matter and the detection distance between the detector and the foreign matter. The radioactivity determination module 12 is configured to determine the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance. The foreign matter information acquisition module 13 is configured to acquire attribute information of the foreign matter and a neutron flux of an environment where the foreign matter is located, the attribute information including mass, natural element content, activation cross sections of various types of the natural elements, and decay constants of activated isotopes corresponding to the various types of the natural elements. The introduction time determination module 14 is configured to determine the introduction time of the foreign matter based on the neutron flux, the attribute information, and the radioactivity of the activated isotope.
[0041] In an embodiment, the radioactivity determination module 12 is specifically configured to: When the detection result is a specific energy absorption rate measured for a gamma point source, the radioactivity determination module 12 is configured to determine the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance according to a formula (1) relationship, the formula (1) relationship being: (1) wherein, K the specific energy absorption rate is the detection result, G a specific energy absorption rate constant is a, A the radioactivity of the activated isotope is A, r the detection distance is d.
[0042] In an embodiment, the radioactivity determination module 12 is specifically configured to: When the detection result is a specific energy absorption rate measured for a gamma point source, the radioactivity determination module 12 is configured to determine the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance according to a formula (2) relationship, the formula (2) relationship being: (2) wherein, K the specific energy absorption rate is the detection result, A the radioactivity of the activated isotope is A, a photon fluence rate of the activated isotope is φ, E a particle average energy of the activated isotope is E, a mass-energy absorption coefficient is μ, r the detection distance is d.
[0043] In an embodiment, the radioactivity determination module 12 is specifically configured to: When the detection result is a dose rate measured for a beta point source, the radioactivity determination module 12 is configured to determine the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance according to a formula (3) relationship, the formula (3) relationship being: (3) wherein, K is the dose rate, A is the radioactivity of the activated isotope, E is the mean particle energy of the activated isotope, is the mass-energy absorption coefficient, r is the detection distance.
[0044] In an embodiment, the introduction time determination module 14 is specifically configured to: determine the relationship between the radioactivity of the activated isotope in the foreign matter and the introduction time based on the neutron flux and the attribute information; determine the introduction time of the foreign matter based on the radioactivity of the activated isotope and the relationship between the radioactivity of the activated isotope and the introduction time.
[0045] In an embodiment, the introduction time determination module 14 is specifically configured to: determine the number of target nuclei of the natural element corresponding to the activated isotope based on the mass and the natural element content of the foreign matter; determine the relationship between the radioactivity of the activated isotope in the foreign matter and the introduction time based on the neutron flux, the number of target nuclei of the natural element corresponding to the activated isotope, the activation cross section of the natural element, and the decay constant of the activated isotope.
[0046] In an embodiment, the introduction time determination module 14 is specifically configured to: determine the number of target nuclei of the natural element corresponding to the activated isotope according to a relationship of formula (4), the relationship of formula (4) being: (4) wherein, m is the mass of the foreign matter, is the natural element content of the foreign matter corresponding to the activated isotope, M i is the molar mass of the natural element, n i is the number of target nuclei of the natural element, N A is the Avogadro constant.
[0047] In an embodiment, the introduction time determination module 14 is specifically configured to: determine the number of activated isotopes formed by the target nuclei of the natural element under the environmental radiation based on the neutron flux, the number of target nuclei of the natural element corresponding to the activated isotope, and the activation cross section of the natural element. determine the activated isotope radioactivity versus introduction time based on the number of activated isotopes and the decay constant of the activated isotopes.
[0048] The specific definition of the detection system 10 can refer to the definition of the detection method method in the foregoing, which will not be repeated here. Each module in the detection system 10 described above can be implemented by software, hardware, and a combination thereof, in whole or in part. The above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned modules.
[0049] In one embodiment, a computer device is provided, and an internal structure diagram of the computer device can be as shown in Figure 5 The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The network interface of the computer device is used to communicate with an external server through a network connection. The computer program is executed by the processor to implement the functions or steps of a Doppler point detection method.
[0050] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the following steps when executing the computer program: obtain a detection result of a detector for a foreign object and a detection distance between the detector and the foreign object; determine a radioactivity of an activated isotope corresponding to the detection result based on the detection result and the detection distance; obtain attribute information of the foreign object and a neutron flux of an environment in which the foreign object is located; the attribute information includes a mass of the foreign object, a natural element content, an activation cross section of each type of the natural element, and a decay constant of an activated isotope corresponding to each type of the natural element; determine an introduction time of the foreign object based on the neutron flux, the attribute information, and the radioactivity of the activated isotope.
[0051] In one embodiment, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the following steps: obtain a detection result of a detector for a foreign object and a detection distance between the detector and the foreign object; Based on the detection result and the detection distance, a radioactivity of the activated isotope corresponding to the detection result is determined. Attribute information of the foreign matter and a neutron flux of an environment where the foreign matter is located are acquired; the attribute information includes a mass of the foreign matter, a natural element content, an activation cross section of each type of the natural element, and a decay constant of an activated isotope corresponding to each type of the natural element; Based on the neutron flux, the attribute information, and the radioactivity of the activated isotope, an introduction time of the foreign matter is determined.
[0052] It should be noted that the functions or steps that can be achieved by the computer readable storage medium or the computer device described above can correspond to the related descriptions of the server side and the client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.
[0053] Those skilled in the art can understand that all or part of the processes in the foregoing method embodiments can be completed by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the foregoing embodiments. Any reference to memory, storage, database, or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink), DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
Claims
1. A method for detecting a foreign object introduction time in a primary circuit of a nuclear power plant, characterized by, The method comprises: obtaining a detection result of a detector for a foreign object and a detection distance between the detector and the foreign object; determining a radioactivity of an activated isotope corresponding to the detection result based on the detection result and the detection distance; obtaining attribute information of the foreign object and a neutron flux of an environment where the foreign object is located; the attribute information comprises a mass of the foreign object, a natural element content, an activation cross section of each type of the natural element, and a decay constant of an activated isotope corresponding to each type of the natural element; determining an introduction time of the foreign object based on the neutron flux, the attribute information, and the radioactivity of the activated isotope.
2. The detection method according to claim 1, characterized in that, The method comprises: when the detection result is a specific energy release rate measured for a gamma point source, determining the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance according to a formula (1) relationship, the formula (1) relationship being: (1) wherein, K is the specific kerma, The method comprises: is the specific kerma constant, A is the activity of the activation isotope, r is the detection distance.
3. The method of claim 1, wherein when the detection result is a specific energy release rate measured for a gamma point source, determining the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance according to a formula (2) relationship, the formula (2) relationship being: when the detection result is a dose rate measured for a beta point source, determining the radioactivity of the activated isotope corresponding to the detection result based on the detection result and the detection distance according to a formula (3) relationship, the formula (3) relationship being: (2) The method comprises: (3) wherein, K is the dose rate, A is the activity of the activation isotope, is the photon fluence rate of the activation isotope, E is the particle mean energy of the activation isotope, is the mass energy absorption coefficient, r is the detection distance.
4. The method of claim 1, wherein determining a relationship between a radioactivity of the activated isotope in the foreign object and the introduction time based on the neutron flux and the attribute information; determining the introduction time of the foreign object based on the radioactivity of the activated isotope and the relationship between the radioactivity of the activated isotope and the introduction time. The method comprises:
5. The detection method according to claim 4, characterized in that, determining a target nucleus number of a natural element corresponding to the activated isotope based on the mass and the natural element content of the foreign object; determining the relationship between the radioactivity of the activated isotope in the foreign object and the introduction time based on the neutron flux, the target nucleus number of the natural element corresponding to the activated isotope, an activation cross section of the natural element, and a decay constant of the activated isotope. The method comprises:
6. The detection method according to claim 4, characterized in that, determining the target nucleus number of the natural element corresponding to the activated isotope according to a formula (4) relationship, the formula (4) relationship being: The method comprises: (4) wherein, m is the mass of the foreign body, is the content of the natural element corresponding to the activated isotope in the foreign body, M i is the molar mass of the natural element, n i is the number of target nuclei of the natural element, N A is the Avogadro constant.
7. The detection method according to claim 4, characterized in that, determining the relationship between the radioactivity of the activated isotope in the foreign object and the introduction time based on the neutron flux, the target nucleus number of the natural element corresponding to the activated isotope, the activation cross section of the natural element, and the decay constant of the activated isotope. determining a number of activated isotopes formed by the natural element target nuclei under environmental radiation based on the neutron flux, a target nucleus number of the activated isotope corresponding natural element, and an activation cross section of the natural element; determining a relationship between radioactivity of the activated isotope and introduction time based on the number of the activated isotope and a decay constant of the activated isotope.
8. A system for detecting the time of introduction of foreign matter into a primary circuit of a nuclear power plant, characterized by The method comprises: an acquisition module configured to acquire a detection result of a detector for a foreign object and a detection distance between the detector and the foreign object; a radioactivity determination module configured to determine radioactivity of an activated isotope corresponding to the detection result based on the detection result and the detection distance; an attribute information acquisition module configured to acquire attribute information of the foreign object and a neutron flux of an environment in which the foreign object is located, the attribute information comprising a mass of the foreign object, a natural element content, an activation cross section of each type of the natural element, and a decay constant of an activated isotope corresponding to each type of the natural element; an introduction time determination module configured to determine an introduction time of the foreign object based on the neutron flux, the attribute information, and the radioactivity of the activated isotope.
9. A computer device, comprising: The computer device comprises: a processor and a memory; the memory is configured to store a computer program; the processor is connected to the memory, and the processor is configured to execute the computer program stored in the memory, so that the computer device executes the detection method in any one of claims 1 to 7.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the detection method in any one of claims 1 to 7.