Plutonium stock neutron monitoring method and device, and critical safety assessment method and system

Abstract

The invention discloses a plutonium stock neutron monitoring method and device and a critical safety assessment method and system, and relates to the technical field of nuclear industry. The monitoring method comprises the following steps: acquiring a first spatial effect correction factor # imgabs0 #, a second spatial effect correction factor # imgabs1 # and a third spatial effect correction factor # imgabs2 #, and determining the equivalent mass # imgabs6 # of plutone-240 according to the first spatial effect correction factor # imgabs3 #, the second spatial effect correction factor # imgabs4 # and the third spatial effect correction factor # imgabs5 #; and determining the plutonium concentration of the solution system according to the equivalent mass # imgabs7 #. According to the embodiment of the invention, the method can improve the accuracy of plutonium stock neutron monitoring.

Description

Technical Field

[0001] The present application belongs to the field of nuclear industry technology, and specifically relates to a plutonium inventory neutron monitoring method and device, and a criticality safety assessment method and system. Background Art

[0002] In systems containing plutonium, spontaneous fission neutrons released by spontaneous fission of plutonium and neutrons produced by decay of plutonium The particles react with N, O and other nuclides in the solution. The reaction released Neutrons can cause induced fission in the system and multiply, and eventually some neutrons leak out, forming monitoring neutron counts in the detection system outside the system. Therefore, the plutonium inventory information in the system can be inferred based on the neutron count rate.

[0003] The spontaneous fission and induced fission neutrons of plutonium have multiplicity, that is, a spontaneous fission or induced fission will release multiple indistinguishable neutrons at the same time, and the number of neutrons released by each spontaneous or induced fission obeys the probability distribution and statistical law. The time coincidence method can be used to measure coincidence events, that is, two or more events that occur simultaneously within a certain period of time, or have a certain correlation in time.

[0004] Boehnel derived the "point model" equations for neutron multiplicity counting based on the plutonium metal system (see: LA-13422-M, Application guide to neutron multiplicity counting; Shi Xueming, Liu Chengan. Application of coincidence counting in plutonium property measurement [J]. Nuclear Physics Review. 2004.) as follows: (1-1) (2-1) in, is the total neutron count rate, represents the neutron counting rate, represents the detection efficiency, express 240 Pu spontaneous fission rate (constant), express 240 Pu equivalent mass, represents the neutron multiplication leakage coefficient, that is, the spontaneous fission neutrons in the system, After multiplication, neutrons eventually leak out of the system. The ratio of the number of leaked neutrons to the number of system source neutrons is express The ratio of the number of neutrons to the number of spontaneous fission neutrons. , express 240The first and second order moments of the neutron multiplicity distribution of Pu spontaneous fission, , represents the first and second moments of the distribution of induced fission neutron multiplicity, is the gate utilization factor.

[0005] The "point model" equations for the plutonium metal system are based on the following assumptions: (1) All induced fission neutrons are almost identical to spontaneous fission neutrons and The neutrons are released simultaneously, regardless of the length of the fission chain; (2) Assume that the neutron detection efficiency and fission probability are uniform throughout the sample; (3) Assuming spontaneous fission neutrons and Neutrons have the same energy spectrum, so the detection efficiency, fission probability, and induced fission proliferation are all the same; (4) The probability of neutron capture without fission is negligible; (5) Neutron multiplicity and neutron energy are unrelated; (6) The neutron’s extinction time in the sample / detector is a single exponential decay.

[0006] In the prior art, the commonly used plutonium inventory neutron monitoring methods include: based on the "Boehnel" point model equations, based on the non-negligible probability of neutron capture without fission in the plutonium solution system, the spontaneous fission neutrons and The neutron energy spectrum has obvious different characteristics, and the neutron absorption effect is corrected. Correction of the difference between the energy spectrum of neutrons and spontaneous fission neutrons, and correction of the difference in detection efficiency between induced fission neutrons and spontaneous fission neutrons. However, the above methods do not take into account the spatial effect of the solution system, resulting in insufficient accuracy in neutron monitoring of plutonium inventory. Summary of the invention

[0007] The technical problem to be solved by the present application is to provide a plutonium inventory neutron monitoring method and device, a criticality safety assessment method and system in view of the above-mentioned deficiencies in the prior art. By using the plutonium inventory neutron monitoring method, the equivalent mass of plutonium-240 can be determined. Taking into account spatial effects to more accurately determine the equivalent mass of plutonium-240 , so according to the equivalent mass , determining the plutonium concentration of the solution system can improve the accuracy of neutron monitoring of plutonium inventories.

[0008] In a first aspect, an embodiment of the present application provides a method for monitoring plutonium inventory neutrons, which is applied to a plutonium-containing solution system, and the method includes: Get the first space effect correction factor , Second space effect correction factor and the third space effect correction factor , where the first spatial effect correction factor is is the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient, the second spatial effect correction factor is the space effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source, the third space effect correction factor for The spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the neutron source; According to the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 ; According to the equivalent mass , determine the plutonium concentration of the solution system.

[0009] In some embodiments of the first aspect, the solution system comprises Sub-districts, is a positive integer; Get the first space effect correction factor , including: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district The first proliferation leakage coefficient, The first detection efficiency and volume, the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the solution system, the first proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the sub-area, the first detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the sub-area, and the first proliferation leakage coefficient, the first detection efficiency and the volume correspond to the sub-areas one by one respectively; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor .

[0010] In some implementations of the first aspect, according to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor , including: The first-type proliferation leakage coefficient, the first-type detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and Substitute the volume into formula (1) to calculate and obtain the first space effect correction factor ; Formula (1) includes: (1) in, Indicates The first detection efficiency of each sub-area; Indicates The first proliferation leakage coefficient of each sub-area; Indicates The volume of each sub-region; represents the total volume of the solution system, that is The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient.

[0011] In some embodiments of the first aspect, the solution system comprises Sub-districts, is a positive integer; Get the second space effect correction factor , including: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the first induced fission reaction rate share is the sub-area The spontaneous fission neutron source is in the sub-region The induced fission reaction rate share caused by the first net proliferation coefficient is the sub-area The net multiplication coefficient of the spontaneous fission neutron source and the second multiplication leakage coefficient are The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, first net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The first induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor .

[0012] In some implementations of the first aspect, according to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor , including: The first-type proliferation leakage coefficient, the first-type detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and Substitute the second detection efficiency into formula (2) and calculate the second spatial effect correction factor ; Formula (2) includes: (2) in, Indicates The volume of each sub-region; represents the total volume of the solution system, that is The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient; represents the first induced fission reaction rate fraction; represents the second detection efficiency; represents the second proliferation leakage coefficient; Represents the first net growth factor.

[0013] In some embodiments of the first aspect, the solution system comprises Sub-districts, is a positive integer; Get the third space effect correction factor , specifically including: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the second induced fission reaction rate share is the sub-area of Neutron source in sub-area The induced fission reaction rate share caused by the second net proliferation coefficient is the sub-area of The net multiplication coefficient of the neutron source, the second multiplication leakage coefficient is the sub-area The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, second net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The second induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor .

[0014] In some implementations of the first aspect, according to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor , specifically including: The first-type proliferation leakage coefficient, the first-type detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and Substitute the second detection efficiency into formula (3) and calculate the third spatial effect correction factor ; Formula (3) includes: (3) in, Indicates The volume of each sub-region; represents the total volume of the solution system, that is The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient; represents the second induced fission reaction rate fraction; represents the second detection efficiency; represents the second proliferation leakage coefficient; Represents the second net growth factor.

[0015] In some embodiments of the first aspect, according to the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 , including: Obtaining first information of the solution system, the first information including the total neutron count rate , consistent with the neutron counting rate , spontaneous fission rate of plutonium-240 , the first type of detection efficiency , the second type of detection efficiency , the first type of proliferation leakage coefficient , the second type of proliferation leakage coefficient , first-order moment of the first kind , the first kind of second order moment , the second first-order moment , the second moment of the second kind AND gate utilization factor ; Among them, the first type of detection efficiency is the detection efficiency of leaked neutrons when the solution system has only spontaneous fission neutron source; the second type of detection efficiency For solution systems only Detection efficiency of leaked neutrons in neutron source; first-class multiplication leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system; the second type of proliferation leakage coefficient For the solution system, only The proliferation leakage coefficient of the solution system when using neutron source; the first-order moment of the first kind is the first-order moment of the spontaneous fission neutron multiplicity distribution in the solution system; the first-kind second-order moment is the second-order moment of the spontaneous fission neutron multiplicity distribution in the solution system; the second-order moment is the first-order moment of the multiplicity distribution of induced fission neutrons in the solution system; the second-order moment of the second kind is the second-order moment of the multiplicity distribution of induced fission neutrons in the solution system; According to the first information, the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 .

[0016] In some implementations of the first aspect, according to the first information, the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 , specifically including: The first information and the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor Substituting into formula (4), the equivalent mass of plutonium-240 is calculated ; Formula (4) includes: (4).

[0017] In some implementations of the first aspect, formula (4) is obtained by a spatial model equation group, and the spatial model equation group includes formula (5) and formula (6), and formula (5) includes: (5) Among them, it means The ratio of the number of neutrons to the number of spontaneous fission neutrons; Formula (6) includes: (6).

[0018] In some embodiments of the first aspect, according to the equivalent mass , determine the plutonium concentration of the solution system, including: Get the first mass percentage of plutonium-238 , the second mass percentage of plutonium-240 , the third mass percentage of plutonium-242 ; Equivalent mass , first mass percentage , the second mass percentage and the third mass percentage Substituting into formula (7), the total mass of plutonium in the solution system is calculated as ; Formula (7) includes: (7) According to the total mass of plutonium , determine the plutonium concentration of the solution system.

[0019] Based on the same inventive concept, in a second aspect, an embodiment of the present application further provides a criticality safety assessment method, which is applied to a plutonium-containing solution system, and the method comprises: Determining the plutonium concentration of the solution system according to the plutonium inventory neutron monitoring method of any one of the first aspects; The criticality safety of the solution system is evaluated using plutonium concentration.

[0020] Based on the same inventive concept, in a third aspect, the present application also provides a plutonium inventory neutron monitoring device, which is applied to a plutonium-containing solution system, and the device includes: The first acquisition module is used to obtain the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , where the first spatial effect correction factor is is the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient, the second spatial effect correction factor is the space effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source, the third space effect correction factor for The spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the neutron source; A first determining module is connected to the first acquiring module and is used to correct the first spatial effect factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 ; The second determining module is connected to the first determining module and is used to determine the equivalent mass , determine the plutonium concentration of the solution system.

[0021] In some embodiments of the third aspect, the solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used for: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district The first proliferation leakage coefficient, The first detection efficiency and volume, the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the solution system, the first proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the sub-area, the first detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the sub-area, and the first proliferation leakage coefficient, the first detection efficiency and the volume correspond to the sub-areas one by one respectively; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor .

[0022] In some embodiments of the third aspect, the solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used for: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the first induced fission reaction rate share is the sub-area The spontaneous fission neutron source is in the sub-region The induced fission reaction rate share caused by the first net proliferation coefficient is the sub-area The net multiplication coefficient of the spontaneous fission neutron source and the second multiplication leakage coefficient are The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, first net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The first induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor .

[0023] In some embodiments of the third aspect, the solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used for: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the second induced fission reaction rate share is the sub-area of Neutron source in sub-area The induced fission reaction rate share caused by the second net proliferation coefficient is the sub-area of The net multiplication coefficient of the neutron source, the second multiplication leakage coefficient is the sub-area The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, second net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The second induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor .

[0024] Based on the same inventive concept, in a fourth aspect, the embodiment of the present application further provides a criticality safety assessment system, which is applied to a plutonium-containing solution system. The criticality safety assessment system includes: The plutonium inventory neutron monitoring device of any one of the third aspects, used to determine the plutonium concentration of a solution system; The evaluation device is connected to the plutonium inventory neutron monitoring device and is used to evaluate the criticality safety of the solution system using plutonium concentration.

[0025] According to the plutonium inventory neutron monitoring method and device, criticality safety assessment method and system provided in the embodiments of the present application, by combining the first space effect correction factor , Second space effect correction factor , and the third space effect correction factor , determine the equivalent mass of plutonium-240 , that is, the first spatial effect correction factor is introduced , Second space effect correction factor and the third space effect correction factor , in order to take into account the spatial effect correction of induced fission neutron proliferation leakage and net neutron proliferation, so as to determine the equivalent mass of plutonium-240 Taking into account spatial effects to more accurately determine the equivalent mass of plutonium-240 , so according to the equivalent mass , determining the plutonium concentration of the solution system can improve the accuracy of neutron monitoring of plutonium inventories. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram showing a flow chart of a method for neutron monitoring of plutonium inventory provided in an embodiment of the present application; Figure 2 A vertical cross-sectional view of a device showing an implementation example of the plutonium inventory neutron monitoring method provided in an embodiment of the present application; Figure 3 A horizontal cross-sectional view of a device showing an implementation example of the plutonium inventory neutron monitoring method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0028] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0030] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship. Example 1

[0031] The plutonium inventory neutron monitoring method provided in the embodiment of the present application can be executed by a plutonium inventory neutron monitoring device and an electronic device, etc. The following takes the plutonium inventory neutron monitoring method executed by an electronic device as an example for description.

[0032] The plutonium inventory neutron monitoring method provided in the embodiment of the present application can be applied to the post-processing process of spent fuel.

[0033] It should be noted that the plutonium inventory neutron monitoring method provided in the embodiments of the present application can be applied to plutonium-containing solution systems, especially large-volume solution systems.

[0034] like Figure 1 As shown, the plutonium inventory neutron monitoring method provided in the embodiment of the present application may include steps S110 to S130.

[0035] S110, obtaining the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , where the first spatial effect correction factor is is the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient, the second spatial effect correction factor is the space effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source, the third space effect correction factor for Spatial effect correction factor for the induced fission neutron multiplication leakage coefficient caused by neutron sources.

[0036] S120, based on the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 .

[0037] S130, based on equivalent mass , determine the plutonium concentration of the solution system.

[0038] According to the plutonium inventory neutron monitoring method provided in the embodiment of the present application, by combining the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 , that is, the first spatial effect correction factor is introduced , Second space effect correction factor and the third space effect correction factor , in order to take into account the spatial effect correction of induced fission neutron proliferation leakage and net neutron proliferation, so as to determine the equivalent mass of plutonium-240 Taking into account spatial effects to more accurately determine the equivalent mass of plutonium-240 , thereby determining the plutonium concentration of the solution system based on the equivalent mass, which can improve the accuracy of neutron monitoring of plutonium inventories.

[0039] The specific implementation methods of the above steps are introduced below.

[0040] In step S110, plutonium-240 is 240 Pu nuclide.

[0041] In some embodiments, the electronic device may pre-store a first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , so that it can be called directly later.

[0042] In other embodiments, the solution system comprises Sub-districts, is a positive integer; Get the first space effect correction factor , including: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district The first proliferation leakage coefficient, The first detection efficiency and volume, the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the solution system, the first proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the sub-area, the first detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the sub-area, and the first proliferation leakage coefficient, the first detection efficiency and the volume correspond to the sub-areas one by one respectively; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor .

[0043] Exemplarily, the solution system includes The sub-areas can be pre-stored in the electronic device for subsequent direct call, and the solution system can also be divided according to the three-dimensional structure of the solution system to obtain Sub-district.

[0044] For example, a three-dimensional Monte Carlo program can be used to calculate The first proliferation leakage coefficient and The first detection efficiency is a first detection efficiency. More specifically, the first proliferation leakage coefficient is the ratio of the number of neutrons generated by the spontaneous fission neutron source after proliferation absorption to the number of neutrons in the spontaneous fission neutron source when there is only a spontaneous fission neutron source in the sub-region. The first detection efficiency can be the ratio of the product of the average reaction rate in the volume of the neutron detection system and the volume of the detection system when only the spontaneous fission neutrons in the sub-region are considered, to the first proliferation leakage coefficient.

[0045] Exemplarily, a three-dimensional Monte Carlo program may be used to calculate the first type of proliferation leakage coefficient and the first type of detection efficiency.

[0046] For example, The volumes can be pre-stored in the electronic device for direct subsequent retrieval.

[0047] It should be noted that Any two volumes in the volumes may be equal or unequal, and there is no limitation here; The value of can be set according to the actual situation and is not limited here. For example, The value can be 3, 5, 10, etc.

[0048] In some examples, according to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor , including: The first-type proliferation leakage coefficient, the first-type detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and Substitute the volume into formula (1) to calculate and obtain the first space effect correction factor ; Formula (1) includes: (1) in, Indicates The first detection efficiency of each sub-area; Indicates The first proliferation leakage coefficient of each sub-area; Indicates The volume of each sub-region; represents the total volume of the solution system, that is The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient.

[0049] That is, the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient takes into account the volume weighting of the first multiplication leakage coefficient power value and the spatial distribution of the first detection efficiency.

[0050] In other embodiments, the solution system comprises Sub-districts, is a positive integer; Get the second space effect correction factor , including: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the first induced fission reaction rate share is the sub-area The spontaneous fission neutron source is in the sub-region The induced fission reaction rate share caused by the first net proliferation coefficient is the sub-area The net multiplication coefficient of the spontaneous fission neutron source and the second multiplication leakage coefficient are The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, first net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The first induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor .

[0051] For example, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and Each second detection efficiency can be pre-stored in the electronic device for subsequent direct call, or can be calculated using a three-dimensional Monte Carlo program.

[0052] In some examples, according to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor , including: The first-type proliferation leakage coefficient, the first-type detection efficiency, Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and Substitute the second detection efficiency into formula (2) and calculate the second spatial effect correction factor ; Formula (2) includes: (2) in, Indicates The volume of each sub-region; represents the total volume of the solution system, that is The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient; represents the first induced fission reaction rate fraction; represents the second detection efficiency; represents the second proliferation leakage coefficient; Represents the first net growth factor.

[0053] That is to say, the spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source takes into account the first induced fission reaction rate distribution produced by the spontaneous fission neutron source in the solution system, as well as the weighting of the spontaneous fission neutron source, while considering the spatial distribution of the second detection efficiency and the difference in neutron energy spectra between the spontaneous fission neutron source and the induced fission source.

[0054] It should be noted that the subscript represents the induced fission neutron, express The average value of .

[0055] In other embodiments, the solution system comprises Sub-districts, is a positive integer; Get the third space effect correction factor , specifically including: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the second induced fission reaction rate share is the sub-area of Neutron source in sub-area The induced fission reaction rate share caused by the second net proliferation coefficient is the sub-area of The net multiplication coefficient of the neutron source, the second multiplication leakage coefficient is the sub-area The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, second net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The second induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor .

[0056] For example, The second induced fission reaction rate fraction, Each second net growth factor can be calculated using a three-dimensional Monte Carlo program.

[0057] For example, The second induced fission reaction rate fraction, Each second net proliferation coefficient can be pre-stored in the electronic device for subsequent direct retrieval.

[0058] In some examples, according to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor , including: The first-type proliferation leakage coefficient, the first-type detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and Substitute the second detection efficiency into formula (3) and calculate the third spatial effect correction factor ; Formula (3) includes: (3) in, Indicates The volume of each sub-region; represents the total volume of the solution system, that is The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient; represents the second induced fission reaction rate fraction; represents the second detection efficiency; represents the second proliferation leakage coefficient; Represents the second net growth factor.

[0059] That is to say, The spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the neutron source is considered in the solution system. The rate distribution of the second induced fission reaction produced by the neutron source, and Neutron source weighting, taking into account the spatial distribution of the second detection efficiency, and The difference in neutron energy spectra between neutron sources and induced fission sources.

[0060] In the embodiment of the present application, the spatial effect correction factor of the induced fission neutron multiplication leakage coefficient takes into account the distribution of the induced fission reaction rate generated by the initial source in the solution system and the weighted distribution of the initial source, while taking into account the spatial distribution of the detection efficiency and the difference in the neutron energy spectrum between the initial source and the induced fission source. The calculation formula is as follows: (8) Among them, the subscript =1 , 2 respectively indicate that the initial source is a spontaneous fission neutron source or Neutron source, subscript represents the induced fission neutron, Solution system sub-area The volume of is the total volume of the solution system, For sub-area The initial source neutrons in the sub-region The induced fission reaction rate share (i.e., the first induced fission reaction rate share or the second induced fission reaction rate share) is For sub-area The net multiplication coefficient of the initial source neutrons (i.e., the first net multiplication coefficient or the second net multiplication coefficient), For sub-area The proliferation leakage coefficient of induced fission neutrons (i.e., the second proliferation leakage coefficient), For sub-area The detection efficiency of induced fission neutrons (i.e., the second detection efficiency).

[0061] In step S120, the electronic device obtains the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor Afterwards, the first spatial effect correction factor can be used , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 .

[0062] In some possible implementations, according to the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 , including: Obtaining first information of the solution system, the first information including the total neutron count rate , consistent with the neutron counting rate , spontaneous fission rate of plutonium-240 , the first type of detection efficiency , the second type of detection efficiency , the first type of proliferation leakage coefficient , the second type of proliferation leakage coefficient , first-order moment of the first kind , the first kind of second order moment , the second first-order moment , the second moment of the second kind AND gate utilization factor ; Among them, the first type of detection efficiency is the detection efficiency of leaked neutrons when the solution system has only spontaneous fission neutron source; the second type of detection efficiency For solution systems only Detection efficiency of leaked neutrons in neutron source; first-class multiplication leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system; the second type of proliferation leakage coefficient For the solution system, only The proliferation leakage coefficient of the solution system when using neutron source; the first-order moment of the first kind is the first-order moment of the spontaneous fission neutron multiplicity distribution in the solution system; the first-kind second-order moment is the second-order moment of the spontaneous fission neutron multiplicity distribution in the solution system; the second-order moment is the first-order moment of the multiplicity distribution of induced fission neutrons in the solution system; the second-order moment of the second kind is the second-order moment of the multiplicity distribution of induced fission neutrons in the solution system; According to the first information, the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 .

[0063] For example, the total neutron count rate , whose unit is count per second (cps), and whose value is measured value or three-dimensional Monte Carlo program simulation value; it corresponds to the neutron counting rate , whose unit is cps, and whose value is the measured value or the simulated value of the three-dimensional Monte Carlo program; spontaneous fission rate , whose unit is fission number per gram second (fission / (gs)), is 240 The intrinsic characteristic constant of the Pu nuclide is independent of the solution system and its value is approximately equal to 475fission / (gs); is the gate utilization factor of the neutron detection system, which represents the gate duration t g The matching count D g The coincidence count when the AND gate duration is ∞ D ∞ Ratio.

[0064] As an example, the first information may be pre-stored in the electronic device so as to be directly called later.

[0065] As another example, the total neutron count rate and the neutron count rate Can be obtained by measurement, or can be calculated by three-dimensional Monte Carlo program; the first type of detection efficiency , the second type of detection efficiency , the first type of proliferation leakage coefficient , the second type of proliferation leakage coefficient , the second first-order moment , the second moment of the second kind AND gate utilization factor All of them can be calculated by three-dimensional Monte Carlo program.

[0066] It should be noted that the first-order moment of the first kind and the second moment of the first kind They are all constants and have nothing to do with the solution system.

[0067] In some examples, based on the first information, the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 , including: The first information and the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor Substituting into formula (4), the equivalent mass of plutonium-240 is calculated ; Formula (4) includes: (4).

[0068] In some examples, formula (4) is obtained by a spatial model equation group, and the spatial model equation group includes formula (5) and formula (6), and formula (5) includes: (5) Among them, it means The ratio of the number of neutrons to the number of spontaneous fission neutrons; Formula (6) includes: (6).

[0069] For example, formula (5) can be rearranged into expression, and then the Substitute the expression into formula (6) and rearrange it to obtain the above formula (4).

[0070] For example, The value can be pre-stored in the electronic device for subsequent direct call.

[0071] The method for real-time online passive neutron monitoring of plutonium inventory in a solution system based on a spatial model (i.e., the method for monitoring plutonium inventory neutrons) provided in the embodiment of the present application is based on the "point model" equation group and its improved version, and takes into account the difference between the initial source distribution and the induced fission source distribution, and performs spatial effect correction for induced fission neutron proliferation leakage and neutron net proliferation, while distinguishing spontaneous fission neutrons and The differences in neutron detection efficiency, proliferation leakage, etc. ultimately lead to a set of spatial model equations that take into account spatial effects and are applicable to solution systems. After taking into account the spatial effects, the measurement results of the neutron count rate of the monitoring system outside the large-volume plutonium solution system can be more accurately reflected, and the plutonium inventory in the system can be more accurately estimated. This method takes into account the characteristics of the induced fission neutron source changing with space, solves the spatial effects of induced fission neutron proliferation leakage and neutron net proliferation in the large-volume solution system, and realizes the neutron passive non-destructive monitoring and analysis of the plutonium content in the large-volume solution system. It is an advanced and engineering-feasible method for monitoring the plutonium content in the solution system.

[0072] The embodiment of the present application effectively solves the spatial effect problem of net proliferation and proliferation leakage coefficient in the method for monitoring the plutonium content in a large volume solution system, and introduces the first spatial effect correction factor The second spatial effect correction factor is introduced by taking into account the volume weighting of the spontaneous fission neutron multiplication leakage coefficient power value and the third space effect correction factor , taking into account the distribution of induced fission reaction rate and the weighted distribution of initial source, while taking into account the spatial distribution of detection efficiency and the difference in neutron energy spectra between the initial source and the induced fission source, the plutonium content monitoring based on the spatial model equation group can well predict the neutron counting rate of the large volume solution system, thus being suitable for the calculation of the plutonium content of the large volume solution system and solving the problem of uneven spatial distribution of the proliferation leakage coefficient.

[0073] In other embodiments, the equivalent mass can also be calculated by formula (9): . Formula (9) includes: (9) In step S130, the electronic device performs the following operations according to the first spatial effect correction factor: , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 Afterwards, the equivalent mass , determine the plutonium concentration of the solution system.

[0074] In some embodiments, according to the equivalent mass , determine the plutonium concentration of the solution system, including: Get the first mass percentage of plutonium-238 , the second mass percentage of plutonium-240 , the third mass percentage of plutonium-242 ; Equivalent mass , first mass percentage , the second mass percentage and the third mass percentage Substituting into formula (7), the total mass of plutonium in the solution system is calculated as ; Formula (7) includes: (7) According to the total mass of plutonium , determine the plutonium concentration of the solution system.

[0075] Exemplarily, the electronic device pre-stores a first mass percentage , the second mass percentage and the third mass percentage , so that it can be called directly later.

[0076] For example, the total mass of plutonium The product of the total volume of the solution system is determined as the plutonium concentration of the solution system.

[0077] The passive neutron real-time online monitoring method for plutonium inventory (ie, the plutonium inventory neutron monitoring method) provided in an embodiment of the present application is described below in conjunction with a specific implementation manner.

[0078] The spatial model equations are as follows: (5) (6) Where: It represents the total neutron count rate in cps, measured value or 3D Monte Carlo program simulation value; Indicates the neutron count rate in cps, measured value or 3D Monte Carlo program simulation value; express 240 The spontaneous fission rate of Pu, in units of fission / (gs), is 240 The intrinsic characteristic constants of the Pu nuclide; It indicates the detection efficiency of the monitoring system for leaked neutrons when there is only spontaneous fission neutron source; Indicates that only When the neutron source is used, the detection efficiency of the monitoring system for leaking neutrons; It indicates the proliferation leakage coefficient of the system when there is only spontaneous fission neutron source in the solution system; Indicates that there is only When the neutron source is used, the proliferation leakage coefficient of the system; , Represent the first and second order moments of the spontaneous fission neutron multiplicity distribution in the solution system; , The first and second order moments representing the distribution of induced fission neutron multiplicity in the solution system; is the gate utilization factor of the neutron detection system, which represents the gate duration t g The matching count D g The coincidence count when the AND gate duration is ∞ D ∞ ratio; express 240 Pu equivalent mass; is the spatial effect correction factor for the spontaneous fission neutron multiplication leakage coefficient; , is the spatial effect correction factor for the induced fission neutron multiplication leakage coefficient; Based on the total neutron count rate and coincident neutron count rate, namely, formula (5) and formula (6), it can be derived that 240 The Pu equivalent mass formula is as follows: (4) If only based on the total neutron count rate, that is, formula (5), it can also be derived that 240 The Pu equivalent mass formula is as follows: (9) Using formula (4) or formula (9), the iterative method can be used to solve . The total mass of plutonium is further obtained as follows: (7) in, , , They are 238 Pu, 240 Pu, 242 The mass percentage of Pu in plutonium; combined with the volume of the solution, we can further obtain information such as plutonium concentration.

[0079] Further, in the method for real-time online passive neutron monitoring of plutonium inventory in a solution system based on the spatial model equation group, the spatial effect correction factor of the induced fission neutron proliferation leakage coefficient takes into account the distribution of the induced fission reaction rate generated by the initial source in the solution system and the weighted distribution of the initial source, while taking into account the spatial distribution of the detection efficiency and the difference in the neutron energy spectrum between the initial source and the induced fission source. The calculation formula is as follows: (8) Among them, the subscript =1 , 2 respectively indicate that the initial source is a spontaneous fission neutron source or Neutron source, subscript represents the induced fission neutron, Solution system sub-area The volume of is the total volume of the solution system, For sub-area The initial source neutrons in the sub-region The fraction of induced fission reaction rate caused by For sub-area The net multiplication factor of the initial source neutrons, For sub-area The multiplication leakage coefficient of induced fission neutrons, For sub-area The detection efficiency of induced fission neutrons. The spatial effect correction coefficient of spontaneous fission neutrons takes into account the volume weighting of the power value of the proliferation leakage coefficient and the spatial distribution of the detection efficiency. The calculation formula is as follows: (1) The solution system is divided into multiple sub-areas. The net proliferation coefficient, proliferation leakage coefficient, neutron detection efficiency, etc. of the statistically induced fission source, as well as the proliferation leakage coefficient and neutron detection efficiency of spontaneous fission neutrons are calculated in each sub-area using a three-dimensional Monte Carlo program. Then, the corresponding spatial correction factor is calculated according to formula (8) and formula (1).

[0080] Furthermore, in the above-mentioned method for real-time online passive neutron monitoring of plutonium inventory in a solution system based on a spatial model (i.e., the method for monitoring plutonium inventory neutrons), the first-order moment of the multiplicity distribution of induced fission neutrons caused by spontaneous fission neutrons in the solution system is and the second moment (i.e., the first-order moment of the second kind and the second moment of the second kind ), the detection efficiency of the neutron detection system for leaked neutrons when only spontaneous fission neutrons are considered (i.e., the first type of detection efficiency ), gate utilization factor , can be calculated using a three-dimensional Monte Carlo program at typical bulk solution concentrations and isotope mass ratios.

[0081] The embodiment of the present application is a method for real-time online passive neutron monitoring of plutonium inventory in a solution system based on a group of spatial model equations (i.e., a method for neutron monitoring of plutonium inventory), including the calculation of overall system parameters, the calculation of spatial effect correction factors, and finally the estimation and solution of plutonium inventory using the group of spatial model equations.

[0082] In order to simplify the sample partition calculation, it is assumed that the sample to be tested is a spherical plutonium solution with a radius of R, and the solution is surrounded by a spherical stainless steel container with a wall thickness of 3 mm. The container is surrounded by a cylindrical measuring device with 18 polyethylene rings arranged inside the cylindrical measuring device. 3 He detector. Five cases of spherical plutonium solution radius R = 10 cm, 15 cm, 20 cm, 25 cm, and 30 cm were analyzed. The entire plutonium inventory neutron monitoring device is as follows Figure 2 and Figure 3 As shown, Figure 2 is a vertical cross-section of the device. Figure 3 It is a horizontal cross-sectional view of the device. 1 is the solution, 2 is the stainless steel container, 3 is 3 He detector (4 atmospheres), 4 is polyethylene, 5 is aluminum (Al) layer, and 6 is cadmium (Cd) lining.

[0083] 240 The spontaneous fission rate and the first and second moments of the spontaneous fission neutron multiplicity distribution of Pu are both nuclides. 240 The inherent properties of Pu, i.e. the fixed values, are 475.276fission / (g•s), 2.156, and 3.825 respectively.

[0084] First, we take a hypothetical plutonium concentration and a typical plutonium isotope mass ratio of a spent fuel assembly of a pressurized water reactor as an example, and use a three-dimensional Monte Carlo program to establish a three-dimensional computational model of a plutonium solution sphere with R = 10 cm. At the same time, we assume that the neutron conformity gate duration t g = 64 microseconds (μs), calculate the overall parameters of the system. Among them, the leakage multiplication factor (i.e. the first type of proliferation leakage coefficient ), leakage multiplication factor (i.e. the second type of proliferation leakage coefficient ) are spontaneous fission source neutrons and The ratio of the number of leaked neutrons to the number of source neutrons after source neutron multiplication, the net multiplication coefficient , net growth coefficient are spontaneous fission source neutrons and The ratio of the number of neutrons produced by the source neutron multiplication to the number of source neutrons. (i.e., the first type of detection efficiency )、 (i.e., the second type of detection efficiency ) Using the detector 3 He's n,p ) reaction rate. The gate durations are defined as t g The first-order moment of the distribution of induced fission neutron multiplicity when there is only spontaneous fission source in the statistical system is (i.e., the first-order moment of the second kind ) and the second moment (i.e., the second-order moment of the second kind ). At the same time, the total neutron counting rate can be statistically obtained and the neutron count rate The Monte Carlo statistical methods of the above-mentioned overall parameters are basically common knowledge or existing technologies in the art.

[0085] The calculation of the space correction factor mainly includes: , , (i.e., step S110, obtaining the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor ). The solution ball of R=10cm is layered, each layer is 1cm, that is The value of is 10. Spontaneous fission neutron sources are set layer by layer to form multiple calculation models, and the sub-areas are counted separately. The initial source neutrons in the sub-region Induced fission reaction rate fraction (i.e. the first induced fission reaction rate fraction ), sub-area The net multiplication coefficient of the initial source neutrons (i.e., the first net growth coefficient ). Set up layer by layer The neutron source forms multiple calculation models to count the sub-areas separately. The initial source neutrons in the sub-region The induced fission reaction rate fraction (i.e., the second induced fission reaction rate fraction) ), sub-area The net multiplication coefficient of the initial source neutrons (i.e., the second net growth factor ). Set the induced fission neutron spectrum layer by layer and calculate the statistical sub-area The multiplication coefficient of induced fission neutrons (i.e. the second proliferation leakage coefficient ), sub-area The detection efficiency of induced fission neutrons (i.e., the second detection efficiency ). The spatial correction factor of induced fission neutrons is calculated according to formula (8) in step S110.

[0086] The spatial effect correction factor of spontaneous fission neutrons is calculated as follows: The sub-areas of the calculation model of spontaneous fission neutron sources are set layer by layer. Neutron detection efficiency (i.e., the first detection efficiency ), spontaneous fission neutron proliferation leakage coefficient (i.e. the first proliferation leakage coefficient ), calculate the spatial correction factor of spontaneous fission neutrons according to formula (1) in step S110.

[0087] For the models with R=15cm, 20cm, 25cm, and 30cm, the same method is used to conduct modeling analysis and statistically obtain the corresponding overall parameters and spatial effect correction factors. The calculation results of these characteristic parameters are shown in Table 1.

[0088] Table 1

[0089] It should be noted that the numerical values ​​in Table 1 are only used for illustration and are not intended to limit the present application.

[0090] Finally, the total neutron count rate simulated by the 3D Monte Carlo program , consistent with the neutron counting rate , as well as the statistical overall parameters, the spatial effect correction factors of spontaneous fission neutrons and induced fission neutrons, combined with the isotope mass ratio of plutonium, the above information is used as input, and the method of step S120 in the embodiment of the present application can be used to calculate The corresponding results are shown in Table 2, where Table 2 is Truth value and Improved models and The spatial model is calculated by these two models. Comparison of results. g in Table 2 represents the mass unit gram. As can be seen from Table 2, the method provided in the embodiment of the present application demonstrates very good estimation accuracy, especially as the radius of the plutonium solution sphere increases, the advantages of the space model equation group are more clearly demonstrated.

[0091] Table 2

[0092] According to the above calculation The value of , as well as the known plutonium isotope composition ratio and solution equipment volume, can be further solved for plutonium inventory information according to formula (9) in step S130.

[0093] The embodiments of the present application have at least the following beneficial effects: 1. Based on the "point model" equations and their improved versions, the difference between the initial source distribution and the induced fission source distribution is considered to correct the spatial effect of induced fission neutron proliferation leakage and neutron net proliferation, and distinguish between spontaneous fission neutrons and The differences in neutron detection efficiency, proliferation leakage, etc. ultimately lead to a set of spatial model equations that take into account spatial effects and are applicable to solution systems. After taking into account the spatial effects, the measurement results of the neutron count rate of the monitoring system outside the large-volume plutonium solution system can be more accurately reflected, and the plutonium inventory in the system can be more accurately estimated. This method takes into account the characteristics of the induced fission neutron source changing with space, solves the spatial effects of induced fission neutron proliferation leakage and neutron net proliferation in the large-volume solution system, and realizes the neutron passive non-destructive monitoring and analysis of the plutonium content in the large-volume solution system. It is an advanced and engineering-feasible method for monitoring the plutonium content in the solution system.

[0094] 2. Effectively solved the spatial effect problem of net proliferation and proliferation leakage coefficient in the plutonium content monitoring method of large volume solution system, and introduced the first spatial effect correction factor The second spatial effect correction factor is introduced by taking into account the volume weighting of the spontaneous fission neutron multiplication leakage coefficient power value and the third space effect correction factor , taking into account the distribution of induced fission reaction rate and the weighted distribution of initial source, while taking into account the spatial distribution of detection efficiency and the difference in neutron energy spectra between the initial source and the induced fission source, the plutonium content monitoring based on the spatial model equation group can well predict the neutron counting rate of the large volume solution system, thus being suitable for the calculation of the plutonium content of the large volume solution system and solving the problem of uneven spatial distribution of the proliferation leakage coefficient. Example 2

[0095] The criticality safety assessment method provided in the embodiment of the present application is also executed by a criticality safety assessment system and an electronic device, etc. The criticality safety assessment method is described below by taking the execution of the electronic device as an example.

[0096] The criticality safety assessment method provided in the embodiment of the present application can be applied to the post-processing process of spent fuel.

[0097] It should be noted that the criticality safety assessment method provided in the embodiment of the present application can be applied to a solution system containing plutonium, especially a large volume solution system.

[0098] The critical safety assessment method provided in the embodiment of the present application may include steps S210 to S220.

[0099] S210. According to the plutonium inventory neutron monitoring method of Example 1, determine the plutonium concentration of the solution system.

[0100] The specific implementation of step S210 can be found in Example 1 and will not be described in detail here.

[0101] S220. Use plutonium concentration to assess the criticality safety of solution systems.

[0102] In some embodiments, when the plutonium concentration is less than or equal to a plutonium concentration threshold, the critical safety of the solution system is determined to be in a safe state; or, when the plutonium concentration is greater than the plutonium concentration threshold, the critical safety of the solution system is determined to be in an unsafe state, and an alarm message is output, the alarm message being used to indicate that the critical safety of the solution system is in an unsafe state.

[0103] It should be noted that the plutonium concentration threshold can be set according to actual conditions and is not limited here. For example, the value range of the plutonium concentration threshold can be 1 g / L to 10 g / L. Example 3

[0104] The embodiment of the present application also provides a plutonium inventory neutron monitoring device, which can be applied to a plutonium-containing solution system, and includes: The first acquisition module is used to obtain the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , where the first spatial effect correction factor is is the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient, the second spatial effect correction factor is the space effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source, the third space effect correction factor for The spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the neutron source; A first determining module is connected to the first acquiring module and is used to correct the first spatial effect factor , Second space effect correction factor and the third space effect correction factor , determine the equivalent mass of plutonium-240 ; The second determining module is connected to the first determining module and is used to determine the equivalent mass , determine the plutonium concentration of the solution system.

[0105] In some embodiments, the solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used for: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district The first proliferation leakage coefficient, The first detection efficiency and volume, the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the solution system, the first proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the sub-area, the first detection efficiency is the detection efficiency of the solution system leaking neutrons when there is only a spontaneous fission neutron source in the sub-area, and the first proliferation leakage coefficient, the first detection efficiency and the volume correspond to the sub-areas one by one respectively; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor .

[0106] In some embodiments, the solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used for: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the first induced fission reaction rate share is the sub-area The spontaneous fission neutron source is in the sub-region The induced fission reaction rate share caused by the first net proliferation coefficient is the sub-area The net multiplication coefficient of the spontaneous fission neutron source and the second multiplication leakage coefficient are The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, first net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The first induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth coefficient, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor .

[0107] In some embodiments, the solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used for: Obtain the first-type proliferation leakage coefficient and the first-type detection efficiency of the solution system, and Sub-district Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency; the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only spontaneous fission neutron source in the solution system, and the second induced fission reaction rate share is the sub-area of Neutron source in sub-area The induced fission reaction rate share caused by the second net proliferation coefficient is the sub-area of The net multiplication coefficient of the neutron source, the second multiplication leakage coefficient is the sub-area The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is the sub-area The detection efficiency of induced fission neutrons, volume, second net multiplication coefficient, second multiplication leakage coefficient and second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The second induced fission reaction rate fraction, and are all positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor .

[0108] In some examples, the plutonium inventory neutron monitoring device provided in the embodiments of the present application may include a plurality of neutron monitoring channels and a data analysis workstation surrounding the solution system. The neutron monitoring channel includes a neutron detector and a corresponding moderator, a shield, electronic components and a display module; the signal of the neutron monitoring channel is transmitted to the data analysis workstation through the data acquisition module, and the data analysis workstation uses the method of embodiment 1 to analyze and process the data.

[0109] The plutonium stock neutron monitoring device provided in the embodiment of the present application can be used to execute the plutonium stock neutron monitoring method, that is, it has the beneficial effects and implementation methods of the plutonium stock neutron monitoring method provided in Example 1 of the present application. For details, please refer to the specific description of the plutonium stock neutron monitoring method in the above Example 1, which will not be repeated in this embodiment. Example 4

[0110] The embodiment of the present application also provides a criticality safety assessment system, which can be applied to a plutonium-containing solution system. The criticality safety assessment system includes: the plutonium inventory neutron monitoring device in Example 3, which is used to determine the plutonium concentration of the solution system; and an assessment device, connected to the plutonium inventory neutron monitoring device, which is used to assess the criticality safety of the solution system using the plutonium concentration.

[0111] The critical safety assessment system provided in the embodiment of the present application can be used to execute the critical safety assessment method, that is, it has the beneficial effects and implementation methods of the critical safety assessment method provided in Example 2 of the present application. For details, please refer to the specific description of the critical safety assessment method in the above Example 2, which will not be repeated in this embodiment.

[0112] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present application, but the present application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of the present application, and these modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. A method for monitoring plutonium inventory neutrons, characterized in that: Applied to a solution system containing plutonium, the method comprises: Get the first space effect correction factor , Second space effect correction factor and the third space effect correction factor , wherein the first spatial effect correction factor is the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient, the second spatial effect correction factor is the spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source, and the third spatial effect correction factor for The spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the neutron source; According to the first spatial effect correction factor , the second spatial effect correction factor and the third spatial effect correction factor , determine the equivalent mass of plutonium-240 ; According to equivalent mass , determine the plutonium concentration of the solution system.

2. The method according to claim 1, characterized in that The solution system comprises Sub-districts, is a positive integer; Get the first space effect correction factor , specifically including: obtaining a first-type proliferation leakage coefficient and a first-type detection efficiency of the solution system, and Sub-district The first proliferation leakage coefficient, The first detection efficiency and a volume, the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of neutron leakage from the solution system when there is only a spontaneous fission neutron source in the solution system, the first proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the sub-area, the first detection efficiency is the detection efficiency of neutron leakage from the solution system when there is only a spontaneous fission neutron source in the sub-area, and the first proliferation leakage coefficient, the first detection efficiency and the volume correspond to the sub-areas one by one respectively; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor .

3. The method according to claim 2, characterized in that According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor , specifically including: The first-type proliferation leakage coefficient, the first-type detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and Substitute the volume into formula (1) to calculate and obtain the first space effect correction factor ; The formula (1) includes: （1） in, Indicates The first detection efficiency of each sub-area; Indicates The first proliferation leakage coefficient of each sub-area; Indicates The volume of each sub-region; represents the total volume of the solution system, i.e. The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient.

4. The method according to claim 1, characterized in that: The solution system comprises Sub-districts, is a positive integer; Get the second space effect correction factor , specifically including: obtaining a first-type proliferation leakage coefficient and a first-type detection efficiency of the solution system, and Sub-district Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and The first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only a spontaneous fission neutron source in the solution system, and the first induced fission reaction rate share is the sub-area The spontaneous fission neutron source is in the sub-region The induced fission reaction rate share caused by the first net proliferation coefficient is the sub-area The net multiplication coefficient of the spontaneous fission neutron source, the second multiplication leakage coefficient is The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is The detection efficiency of induced fission neutrons, the volume, the first net proliferation coefficient, the second proliferation leakage coefficient and the second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The first induced fission reaction rate fraction, and All are positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor .

5. The method according to claim 4, characterized in that According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor , specifically including: The first-type proliferation leakage coefficient, the first-type detection efficiency, Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and Substitute the second detection efficiency into formula (2) and calculate the second spatial effect correction factor ; The formula (2) includes: （2） in, Indicates The volume of each sub-region; represents the total volume of the solution system, i.e. The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient; represents the first induced fission reaction rate fraction; represents the second detection efficiency; represents the second proliferation leakage coefficient; Represents the first net growth factor.

6. The method according to claim 1, characterized in that The solution system comprises Sub-districts, is a positive integer; Get the third space effect correction factor , specifically including: obtaining a first-type proliferation leakage coefficient and a first-type detection efficiency of the solution system, and Sub-district Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only a spontaneous fission neutron source in the solution system, and the second induced fission reaction rate share is the sub-area of Neutron source in sub-area The second net proliferation coefficient is the fraction of the induced fission reaction rate caused by of The net multiplication coefficient of the neutron source, the second multiplication leakage coefficient is The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is The detection efficiency of induced fission neutrons, the volume, the second net proliferation coefficient, the second proliferation leakage coefficient and the second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The second induced fission reaction rate fraction, and All are positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor .

7. The method according to claim 6, characterized in that According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor , specifically including: The first-type proliferation leakage coefficient, the first-type detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and Substitute the second detection efficiency into formula (3) and calculate the third spatial effect correction factor ; The formula (3) includes: （3） in, Indicates The volume of each sub-region; represents the total volume of the solution system, i.e. The sum of the volumes; represents the first type of detection efficiency; represents the first type proliferation leakage coefficient; represents the second induced fission reaction rate fraction; represents the second detection efficiency; represents the second proliferation leakage coefficient; Represents the second net growth factor.

8. The method according to claim 1, characterized in that: According to the first spatial effect correction factor , the second spatial effect correction factor and the third spatial effect correction factor , determine the equivalent mass of plutonium-240 , specifically including: Acquire first information of the solution system, wherein the first information includes a total neutron count rate , consistent with the neutron counting rate , spontaneous fission rate of plutonium-240 , the first type of detection efficiency , the second type of detection efficiency , the first type of proliferation leakage coefficient , the second type of proliferation leakage coefficient , first-order moment of the first kind , the first kind of second order moment , the second first-order moment , the second moment of the second kind AND gate utilization factor ; Wherein, the first type of detection efficiency is the detection efficiency of leaked neutrons when the solution system has only spontaneous fission neutron sources; the second type of detection efficiency For the solution system only Detection efficiency of leaked neutrons in neutron source; first-class multiplication leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system; the second type proliferation leakage coefficient For the solution system only When the neutron source is used, the proliferation leakage coefficient of the solution system; the first-order moment is the first-order moment of the spontaneous fission neutron multiplicity distribution in the solution system; the first-order second-order moment is the second-order moment of the spontaneous fission neutron multiplicity distribution in the solution system; the second first-order moment is the first-order moment of the multiplicity distribution of induced fission neutrons in the solution system; the second-order moment of the second kind is the second-order moment of the multiplicity distribution of induced fission neutrons in the solution system; According to the first information, the first spatial effect correction factor , the second spatial effect correction factor and the third spatial effect correction factor , determine the equivalent mass of plutonium-240 .

9. The method according to claim 8, characterized in that According to the first information, the first spatial effect correction factor , the second spatial effect correction factor and the third spatial effect correction factor , determine the equivalent mass of plutonium-240 , specifically including: The first information, the first spatial effect correction factor , the second spatial effect correction factor and the third spatial effect correction factor Substituting into formula (4), the equivalent mass of plutonium-240 is calculated ; The formula (4) includes: （4）。 10. The method according to claim 9, characterized in that The formula (4) is obtained from the space model equation group, and the space model equation group includes formula (5) and formula (6). The formula (5) includes: （5） in, express The ratio of the number of neutrons to the number of spontaneous fission neutrons; The formula (6) includes: （6）。 11. The method according to claim 1, characterized in that According to equivalent mass , determining the plutonium concentration of the solution system, specifically comprising: Get the first mass percentage of plutonium-238 , the second mass percentage of plutonium-240 , the third mass percentage of plutonium-242 ; Equivalent mass , first mass percentage , the second mass percentage and the third mass percentage Substituting into formula (7), the total mass of plutonium in the solution system is calculated as ; The formula (7) includes: （7） According to the total mass of plutonium , determine the plutonium concentration of the solution system.

12. A criticality safety assessment method, characterized in that: Applied to a solution system containing plutonium, the method comprises: The method for neutron monitoring of plutonium inventory according to any one of claims 1 to 11, determining the plutonium concentration of the solution system; The plutonium concentration is used to evaluate the criticality safety of the solution system.

13. A plutonium inventory neutron monitoring device, characterized in that: Applicable to a solution system containing plutonium, the device comprises: The first acquisition module is used to obtain the first spatial effect correction factor , Second space effect correction factor and the third space effect correction factor , wherein the first spatial effect correction factor is the spatial effect correction factor of the spontaneous fission neutron multiplication leakage coefficient, the second spatial effect correction factor is the spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the spontaneous fission neutron source, and the third spatial effect correction factor for The spatial effect correction factor of the induced fission neutron multiplication leakage coefficient caused by the neutron source; A first determining module is connected to the first acquiring module and is used to correct the first spatial effect factor according to the first spatial effect correction factor. , the second spatial effect correction factor and the third spatial effect correction factor , determine the equivalent mass of plutonium-240 ; A second determining module is connected to the first determining module and is used to determine the equivalent mass , determine the plutonium concentration of the solution system.

14. The device according to claim 13, characterized in that The solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used to: obtaining a first-type proliferation leakage coefficient and a first-type detection efficiency of the solution system, and Sub-district The first proliferation leakage coefficient, The first detection efficiency and a volume, the first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of neutron leakage from the solution system when there is only a spontaneous fission neutron source in the solution system, the first proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the sub-area, the first detection efficiency is the detection efficiency of neutron leakage from the solution system when there is only a spontaneous fission neutron source in the sub-area, and the first proliferation leakage coefficient, the first detection efficiency and the volume correspond to the sub-areas one by one respectively; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, The first proliferation leakage coefficient, The first detection efficiency and volume, determine the first spatial effect correction factor ; and / or, The solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used to: obtaining a first-type proliferation leakage coefficient and a first-type detection efficiency of the solution system, and Sub-district Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and The first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only a spontaneous fission neutron source in the solution system, and the first induced fission reaction rate share is the sub-area The spontaneous fission neutron source is in the sub-region The induced fission reaction rate share caused by the first net proliferation coefficient is the sub-area The net multiplication coefficient of the spontaneous fission neutron source, the second multiplication leakage coefficient is The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is The detection efficiency of induced fission neutrons, the volume, the first net proliferation coefficient, the second proliferation leakage coefficient and the second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The first induced fission reaction rate fraction, and All are positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The first induced fission reaction rate share, The first net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the second spatial effect correction factor ; and / or, The solution system comprises Sub-districts, is a positive integer; The first acquisition module is specifically used to: obtaining a first-type proliferation leakage coefficient and a first-type detection efficiency of the solution system, and Sub-district Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The first type of proliferation leakage coefficient is the proliferation leakage coefficient of the solution system when there is only a spontaneous fission neutron source in the solution system, the first type of detection efficiency is the detection efficiency of the leakage neutrons of the solution system when there is only a spontaneous fission neutron source in the solution system, and the second induced fission reaction rate share is the sub-area of Neutron source in sub-area The second net proliferation coefficient is the fraction of the induced fission reaction rate caused by of The net multiplication coefficient of the neutron source, the second multiplication leakage coefficient is The multiplication leakage coefficient of induced fission neutrons, the second detection efficiency is The detection efficiency of induced fission neutrons, the volume, the second net proliferation coefficient, the second proliferation leakage coefficient and the second detection efficiency correspond to sub-areas one by one, and one sub-area corresponds to The second induced fission reaction rate fraction, and All are positive integers; According to the first type of proliferation leakage coefficient, the first type of detection efficiency, Volume, The second induced fission reaction rate fraction, The second net growth factor, The second proliferation leakage coefficient, and The second detection efficiency determines the third spatial effect correction factor .

15. A criticality safety assessment system, characterized in that: Applied to a solution system containing plutonium, the criticality safety assessment system comprises: The plutonium inventory neutron monitoring device according to claim 13 or 14, used to determine the plutonium concentration of a solution system; An evaluation device is connected to the plutonium inventory neutron monitoring device and is used to evaluate the criticality safety of the solution system using the plutonium concentration.

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