Method, device and equipment for nuclear criticality safety calculation of uranium solution

Abstract

The present invention provides a method, apparatus and equipment for nuclear criticality safety calculation of uranium solution. Among them, the method includes: obtaining material parameters and geometric parameters in the uranium solution system; the uranium solution system is a dissolver containing uranium solution; the uranium enrichment of the uranium solution is less than 20%; constructing a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods; calculating the effective neutron multiplication factor of the uranium solution system through the lattice model. The solution provided by the present invention can improve the accuracy and precision of nuclear criticality safety calculation.

Description

Technical Field

[0001] The present invention relates to the technical field of post-treatment, and particularly to a method, device and equipment for nuclear criticality safety calculation of uranium solution. Background Art

[0002] Nuclear fuel reprocessing is the central link of the nuclear fuel cycle system and also the weakest link in the nuclear fuel cycle system. It is an outstanding factor restricting the rapid development of nuclear energy in China. Therefore, it is necessary to accelerate the technical development process of nuclear fuel reprocessing in China.

[0003] In the process of nuclear fuel reprocessing, nuclear criticality safety is of crucial importance and directly affects production capacity and process design. Therefore, it has certain practical significance to effectively calculate and evaluate the nuclear criticality safety of post-treatment equipment.

[0004] In the process of nuclear fuel reprocessing, the reactivity effect caused by the spatial variation of nuclear fuel concentration is an important issue in nuclear criticality safety. Especially, the modeling of criticality calculation for solid-liquid mixtures of low-enriched (≤wt20%) uranium has always been a difficult point in nuclear criticality safety calculation and evaluation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method, device and equipment for nuclear criticality safety calculation of uranium solution, so as to improve the accuracy of nuclear criticality safety calculation and ensure the safe progress of the reaction.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A method for nuclear criticality safety calculation of uranium solution, comprising:

[0008] Obtaining material parameters and geometric parameters in the uranium solution system; the uranium solution system is a dissolver containing uranium solution; the uranium enrichment of the uranium solution is less than 20%;

[0009] Constructing a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods;

[0010] Calculating the effective neutron multiplication factor of the uranium solution system through the lattice model.

[0011] Optionally, the lattice model is located in a hanging basket in the uranium solution system.

[0012] Optionally, the lattice model is an array formed by uniformly distributing a plurality of nuclear fuel rods in a moderator, and the plurality of nuclear fuel rods are uranium dioxide nuclear fuel rods.

[0013] Optionally, the uranium dioxide nuclear fuel rod is a cylinder, and in the array formed by the plurality of uranium dioxide nuclear fuel rods and the moderator, any three adjacent nuclear fuel rods are distributed in an equilateral triangle.

[0014] Optionally, the material parameters include: 235 U and 238 the abundance of U, the density of uranium dioxide in the uranium solution system, the materials and densities of the moderator and reflector in the uranium solution system;

[0015] The geometric parameters include: the length and radius of the uranium dioxide nuclear fuel rods in the lattice model, the rod pitch between two adjacent uranium dioxide nuclear fuel rods, the size and material of the container.

[0016] Optionally, both the moderator and the reflector are water.

[0017] Optionally, constructing a lattice model according to the material parameters, the geometric parameters and the nuclear fuel rods includes:

[0018] Obtaining the pitch between the uranium dioxide fuel rods and the radius of the uranium dioxide fuel rods in the lattice model according to the infinite neutron multiplication factor of the uranium solution system;

[0019] Obtaining the effective neutron multiplication factors of the uranium dioxide fuel rods at multiple different preset radii according to the rod pitch between the ends of the uranium dioxide fuels;

[0020] Obtaining a first curve graph of the rod pitch and the effective neutron multiplication factor, and a second curve graph of the radius of the uranium dioxide nuclear fuel rods and the effective neutron multiplication factor according to the effective neutron multiplication factor, the rod pitch between the uranium dioxide nuclear fuel rods and the radius of the uranium dioxide fuel rods;

[0021] Determining that the extreme values in the first curve graph and the second curve graph are the target rod pitch and the target nuclear fuel rod radius of the lattice model.

[0022] Optionally, calculating the effective neutron multiplication factor of the uranium solution system through the lattice model includes:

[0023] According to the formula: K eff = εpfηΛ s Λ d , calculating the effective neutron multiplication factor of the uranium solution system, where Λ s is the neutron non-leakage rate during the moderation process, Λ d is the non-leakage rate of thermal neutrons during the diffusion process, p is the resonance escape probability, f is the thermal neutron utilization factor, η is the number of effective fission neutrons, and ε is the fast neutron multiplication factor.

[0024] A device for calculating the nuclear critical safety of a uranium solution, comprising:

[0025] An acquisition module, configured to acquire material parameters and geometric parameters in a uranium solution system; the uranium solution system is a dissolver containing uranium solution;

[0026] A processing module, configured to construct a lattice model according to the material parameters, the geometric parameters, and nuclear fuel rods; calculate the uranium solution system through the lattice model, and obtain a calculation result of an effective neutron multiplication factor of the uranium solution system.

[0027] A computing device, including a processor, a memory, and a program or instruction stored on the memory and executable on the processor, where when the program or instruction is executed by the processor, the method described above is implemented.

[0028] The above solution of the present invention at least includes the following beneficial effects:

[0029] In the above solution of the present invention, by acquiring material parameters and geometric parameters in a uranium solution system; the uranium solution system is a dissolver containing uranium solution; the uranium enrichment of the uranium solution is less than 20%; constructing a lattice model according to the material parameters, the geometric parameters, and nuclear fuel rods; calculating the effective neutron multiplication factor of the uranium solution system through the lattice model, the accuracy and precision of nuclear critical safety calculation are improved, and thus the safety of nuclear reaction equipment is ensured. Description of the Drawings

[0030] Figure 1 is a schematic flowchart of a method for nuclear critical safety calculation of uranium solution provided by an embodiment of the present invention;

[0031] Figure 2 is provided by an optional embodiment of the present invention for different 235 U enrichment, a schematic diagram of the ratio relationship between K inf of the uranium solution system and H / 5;

[0032] Figure 3 is a top view of a lattice model provided by an optional embodiment of the present invention;

[0033] Figure 4 is a cross-sectional view of a lattice model provided by an optional embodiment of the present invention;

[0034] Figure 5 is a first curve graph of K eff provided by an optional embodiment of the present invention and rod pitch;

[0035] Figure 6 is a second curve graph of K eff provided by an optional embodiment of the present invention and rod radius;

[0036] Figure 7It is a schematic diagram of a device module for nuclear criticality safety calculation of uranium solution provided by an alternative embodiment of the present invention.

[0037] Explanation of the reference numerals in the attached drawings: 1. Nuclear fuel rod; 2. Dissolver; 3. Large basket. Specific implementation mode

[0038] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0039] As Figure 1 shown, an embodiment of the present invention proposes a method for nuclear criticality safety calculation of uranium solution, including:

[0040] Step 11, obtaining the material parameters and geometric parameters in the uranium solution system; the uranium solution system is a dissolver containing uranium solution; the uranium enrichment of the uranium solution is less than 20%;

[0041] Step 12, constructing a lattice model according to the material parameters, the geometric parameters and the nuclear fuel rod;

[0042] Step 13, calculating the effective neutron multiplication factor of the uranium solution system through the lattice model.

[0043] In this embodiment, in the uranium solution system, the uranium enrichment is less than 20%, and the uranium solution has a particle size reaching the centimeter level, that is, an obvious solid-liquid mixture;

[0044] The dissolver may include structures such as a dissolving tank, a large basket, a small basket, a circulation plate groove, etc. Before post-treatment, the nuclear fuel assembly can be cut into short sections by a shearing machine. The nuclear fuel assembly is a fuel assembly containing uranium element, with a length generally of 2-5 cm, and is restricted to be dissolved in the large basket; during the dissolution process, the nuclear fuel short sections gradually decrease, and at the same time the uranium concentration of the solution gradually increases. After the dissolution is completed, a uranium solution with a uniform concentration is obtained; preferably, the dissolver can be made of stainless steel;

[0045] In an alternative embodiment of the present invention, the applicable specifications of the dissolver can be: a diameter of 31.5 cm and a height of 200 cm. The large basket is a cylinder, and the applicable specifications can be: a diameter of 27.5 cm;

[0046] In the uranium solution system, the fuel rod is a uranium dioxide nuclear fuel rod, and the total mass of uranium dioxide in the system remains unchanged. Preferably, this can be achieved by adjusting the radius, height, and density of the fuel rod. The lattice model is a geometric model under the critical accident scenario assumption in a low-enriched uranium solution system. The nuclear fuel rods that make up the lattice model are uranium dioxide nuclear fuel rods. A lattice model is constructed in the dissolver through the material parameters, geometric parameters, and the nuclear fuel rods, and based on the constructed lattice model, a Monte Carlo program is used to perform nuclear reaction safety calculations to obtain the effective neutron multiplication factor of the uranium solution system, and the effective neutron multiplication factor is used as the final calculation result. Moreover, the lattice model can improve the accuracy of the effective neutron multiplication factor calculation and standardize the nuclear critical safety calculation during the reprocessing process.

[0047] Further, the material parameters include: 235 The abundances of 238 U and

[0048] U, the density of uranium dioxide in the uranium solution system, and the materials and densities of the moderator and reflector in the uranium solution system.

[0049] In this embodiment, when performing nuclear reaction safety calculations using a Monte Carlo program based on the lattice model, the required parameters include material parameters and geometric parameters. Among them, the geometric parameters mainly include the thickness of the full-water reflector layer and the structure of the lattice model from the outside to the inside. The structure of the lattice model can include: the side length of the equilateral triangle formed when the uranium dioxide nuclear fuel rods are arranged in an equilateral triangle, the radius and length of the uranium dioxide nuclear fuel rods, the spacing between the uranium dioxide nuclear fuel rods, the total mass of the uranium dioxide nuclear fuel rods, etc.

[0050] In an alternative embodiment of the present invention, the lattice model is located in the basket in the uranium solution system and is in the large basket 3. For UO2-H2O solution systems with different 235 U enrichment degrees, the variation of the infinite neutron multiplication factor with H / 5 can be calculated. For comparison, uranium solution systems with enrichment degrees of 90%, 40%, 20%, 10%, and 4.45% are also calculated in sequence. As inf shown, for high-enrichment uranium solution systems, the maximum value of the infinite neutron multiplication factor appears at a water content of 0, and the non-uniformity effect is small. For low-enrichment uranium solution systems, when the uranium enrichment degree is lower than 20%, due to the influence of Figure 2 inf 238 ​​Regarding the influence of U resonance absorption, the non-uniform effect is relatively large, and the optimal moderation condition is at the atomic number ratio of H / 5 being 200, which is the theoretical basis for establishing the grid model;

[0051] Preferably, the infinite neutron multiplication factor K inf can be calculated by the following formula:

[0052] K inf = εpfη;

[0053] where p is the resonance escape probability in the uranium solution system, f is the thermal neutron utilization factor in the uranium solution system, η is the number of effective fission neutrons in the uranium solution system, and ε is the fast neutron multiplication factor;

[0054] As Figures 3 to 4 shown, the grid model is composed of multiple uranium dioxide nuclear fuel rods 1 with the same diameter and height, a moderator, and a reflector; preferably, both the moderator 1 and the reflector 3 can be water to ensure safety and moderation effect during the reaction process; the size of the nuclear fuel rod can be the diameter of the nuclear fuel rod in the nuclear fuel assembly, and an optional parameter is 0.816 cm; during the dissolution of the nuclear fuel assembly, the diameter of the nuclear fuel rod will also decrease accordingly; the height of the nuclear fuel rod can be set according to the height of the dissolver;

[0055] The uranium dioxide nuclear fuel rods 1 are placed in the large basket 3, the large basket 3 is placed in the dissolver 1, the moderator is filled between the multiple uranium dioxide nuclear fuel rods 1, and the reflector is placed outside the dissolver 2 to form a full-water reflector layer of the grid model;

[0056] As Figures 3 to 4 shown, in an optional embodiment of the present invention, an array formed by uniformly distributing multiple uranium dioxide nuclear fuel rods 1 in the moderator is used to ensure the uniformity of the entire uranium solution system and achieve the optimal moderation effect; preferably, the multiple nuclear fuel rods 1 are uranium dioxide nuclear fuel rods.

[0057] In an optional embodiment of the present invention, the uranium dioxide nuclear fuel rod is a cylinder, and in the array formed by multiple uranium dioxide nuclear fuel rods and the moderator 2, any three adjacent nuclear fuel rods are distributed in an equilateral triangle.

[0058] In this embodiment, any three adjacent uranium dioxide nuclear fuel rods in the array are arranged in an equilateral triangle to ensure that the distance between each uranium dioxide nuclear fuel rod and the surrounding uranium dioxide nuclear fuel rods is the same, ensuring the optimal moderation effect during the reaction;

[0059] In an optional embodiment of the present invention, the above step 12 may include:

[0060] Step 121: Obtain the spacing between uranium dioxide fuel rods and the radius of the uranium dioxide fuel rods required for constructing the lattice model based on the infinite neutron multiplication factor of the uranium solution system.

[0061] Step 122: Obtain the effective neutron multiplication factors of the uranium dioxide nuclear fuel rods at multiple different preset radii according to the rod spacing between the uranium dioxide nuclear fuel rods.

[0062] Step 123: Obtain a first curve graph of the rod spacing versus the effective neutron multiplication factor and a second curve graph of the radius of the uranium dioxide nuclear fuel rod versus the effective neutron multiplication factor according to the effective neutron multiplication factor, the rod spacing between the uranium dioxide nuclear fuel rods, and the radius of the uranium dioxide nuclear fuel rod.

[0063] Step 124: Determine that the extreme values in the first curve graph and the second curve graph are the target rod spacing and the target nuclear fuel rod radius of the lattice model.

[0064] In this embodiment, according to the infinite neutron multiplication factor K of the uranium solution system inf , determine the radius of the nuclear fuel rods and the spacing between the nuclear fuel rods for constructing the lattice model; the size of the spacing between the nuclear fuel rods can change the size of the moderator between the nuclear fuel rods, and thus the moderation effect of the reaction in the uranium solution system can be controlled according to the size of the moderator.

[0065] By setting different rod spacings between the nuclear fuel rods and the radius of the nuclear fuel rods, the effective neutron multiplication factor K of the uranium solution system can be calculated eff , determine the moderation effect of the uranium solution system at different spacings, and respectively plot a first curve graph of the rod spacing between the nuclear fuel rods versus the effective neutron multiplication factor K eff ; and a second curve graph of the radius of the nuclear fuel rod versus the effective neutron multiplication factor K eff ;

[0066] According to the first curve graph and the second curve graph, when the value of the effective neutron multiplication factor K corresponding to the peak point in the curve graph is the largest, the radius of the nuclear fuel rod and the rod spacing corresponding to the peak point at this time are the target parameters for constructing the lattice model; when the value of the effective neutron multiplication factor K eff is the largest, the moderation condition is optimal when the uranium solution system reacts, and the effective neutron multiplication factor K eff is the largest, effWhen the value reaches the maximum and is always less than 1, it indicates that the target rod spacing between the nuclear fuel rods for constructing the lattice model and the target radius of the nuclear fuel rods are optimal at this time; based on the target radius and target rod spacing of the nuclear fuel rods, a lattice model is constructed, and the target radius and target rod spacing of the nuclear fuel rods are used as parameters of the lattice model and input into the Monte Carlo program for calculation to obtain the effective neutron multiplication factor K of the final system eff , as the final calculation result;

[0067] In an achievable example, taking the radius of the nuclear fuel rod as 0.6 cm as an example for calculation, during the calculation process, by adjusting the spacing between the nuclear fuel rods, the effective neutron multiplication factor K at the same radius and different rod spacings is calculated eff , and the results are shown in Table 1, and a first curve graph of the effective neutron multiplication factor and the rod spacing is drawn based on the calculation results in Table 1, as Figure 5 shown;

[0068] Serial number Rod pitch / cm <![CDATA[K eff > 1 1.9 0.9237 2 2.0 0.9277 3 2.1 0.9297 4 2.2 0.9263 5 2.3 0.9183

[0069] Table 1 Calculation results with the fuel rod radius of 0.6 cm

[0070] From Table 1 and Figure 5 it can be seen that for the case where the radius of the nuclear fuel rod is 0.6 cm, the point to be selected is the point corresponding to K eff = 0.9297, and its rod spacing is 2.1 cm.

[0071] Furthermore, the optimal moderation for different rod radii is calculated, and the corresponding calculation results are shown in Table 2, and drawn and Figure 2 . The effective neutron multiplication factor K at different radii and different rod spacings is calculated eff , and the results are shown in Table 2, and a second curve graph of the effective neutron multiplication factor and the rod radius is drawn based on the calculation results in Table 2; as Figure 6 shown,

[0072]

[0073]

[0074] Table 2 Calculation results for different rod radii

[0075] From Table 2 and Figure 2 it can be seen that the radius of the peak corresponding point is 0.4 cm. When modeling the dissolver using the lattice model, the modeling parameters selected can be the radius of the nuclear fuel rod of 0.4 cm and the rod spacing of the nuclear fuel rod of 1.5 cm, which are the modeling parameters of the optimal lattice model;

[0076] In an alternative embodiment of the present invention, the above step 13 may include:

[0077] Step 131, according to the formula: K eff = εpfηΛ s Λ d , calculate the effective neutron multiplication factor of the uranium solution system, where Λ s is the neutron non-leakage rate during the moderation process, Λ d is the non-leakage rate of thermal neutrons during the diffusion process, p is the probability of escape from resonance capture, f is the thermal neutron utilization factor, and η is the number of effective fission neutrons.

[0078] In this embodiment, through the constructed lattice model, as well as the radius and rod pitch of the nuclear fuel rods in the lattice model, the effective neutron multiplication factor of the uranium solution system is calculated. Further, according to the finally calculated effective neutron multiplication factor, the parameters of the system during the reaction process can be adjusted to ensure the safety of the equipment during operation.

[0079] An embodiment of the present invention also provides a device 70 for nuclear criticality safety calculation of uranium solution, including:

[0080] An acquisition module 71, configured to acquire the material parameters and geometric parameters in the uranium solution system; the uranium solution system is a dissolver containing uranium solution;

[0081] A processing module 72, configured to construct a lattice model according to the material parameters, the geometric parameters, and nuclear fuel rods; calculate the uranium solution system through the lattice model, and obtain the calculation result of the effective neutron multiplication factor of the uranium solution system.

[0082] Optionally, the lattice model is located in a basket in the uranium solution system.

[0083] Optionally, the lattice model is an array formed by uniformly distributing a plurality of nuclear fuel rods in a moderator, and the plurality of nuclear fuel rods are uranium dioxide nuclear fuel rods.

[0084] Optionally, the uranium dioxide nuclear fuel rod is a cylinder, and in the array formed by the plurality of uranium dioxide nuclear fuel rods and the moderator, any three adjacent nuclear fuel rods are distributed in an equilateral triangle.

[0085] Optionally, the material parameters include: 235 The abundances of U and 238 U, the density of uranium dioxide in the uranium solution system, the materials and densities of the moderator and reflector in the uranium solution system;

[0086] The geometric parameters include: the length and radius of the uranium dioxide nuclear fuel rods in the lattice model, the rod pitch between two adjacent uranium dioxide nuclear fuel rods, the size and material of the container.

[0087] Optionally, both the moderator and the reflector are water.

[0088] Optionally, the processing module 72 is configured to construct a lattice model according to the material parameters, the geometric parameters, and the nuclear fuel rods, including:

[0089] Obtaining the pitch between the uranium dioxide fuel rods and the radius of the uranium dioxide fuel rods in the lattice model according to the infinite neutron multiplication factor of the uranium solution system;

[0090] Obtaining the effective neutron multiplication factors of the uranium dioxide fuel rods at multiple different preset radii according to the pitch between the uranium dioxide nuclear fuel rods;

[0091] Obtaining a first curve graph of the pitch and the effective neutron multiplication factor, and a second curve graph of the radius of the uranium dioxide nuclear fuel rods and the effective neutron multiplication factor according to the effective neutron multiplication factor, the pitch between the uranium dioxide nuclear fuel rods, and the radius of the uranium dioxide fuel rods;

[0092] Determining that the extreme values in the first curve graph and the second curve graph are the target pitch and the target nuclear fuel rod radius of the lattice model.

[0093] Optionally, the processing module 72 is configured to calculate the effective neutron multiplication factor of the uranium solution system through the lattice model, including:

[0094] According to the formula: K eff = εpfηΛ s Λ d , calculating the effective neutron multiplication factor of the uranium solution system, where Λ s is the neutron non-leakage rate during the moderation process, Λ d is the non-leakage rate of thermal neutrons during the diffusion process, p is the resonance escape probability, f is the thermal neutron utilization factor, η is the number of effective fission neutrons, and ε is the fast neutron multiplication factor.

[0095] It should be noted that this device corresponds to the above method, and all implementation manners in the above method embodiments are applicable to the embodiments of this device and can achieve the same technical effects.

[0096] An embodiment of the present invention further provides a computing device, including: a processor, a memory, a communication interface, and a communication bus, and the processor, the memory, and the communication interface complete communication with each other through the communication bus;

[0097] The memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform operations corresponding to the above method.

[0098] It should be noted that the computing device corresponds to the above method, and all implementation manners in the above method embodiments are applicable to the embodiments of this computing device and can achieve the same technical effects.

[0099] An embodiment of the present invention also provides a computer-readable storage medium storing instructions, which when running on a computer, cause the computer to execute the method as described above.

[0100] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0101] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be repeated here.

[0102] In the embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in an electrical, mechanical, or other form.

[0103] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0104] In addition, the functional units in each embodiment of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0105] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs.

[0106] In addition, it should be noted that in the device and method of the present invention, obviously, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present invention. And, the steps of performing the above series of processes can naturally be executed in chronological order according to the described order, but it is not necessary to execute them in chronological order. Some steps can be executed in parallel or independently of each other. For those of ordinary skill in the art, it can be understood that all or any steps or components of the method and device of the present invention can be implemented in any computing device (including a processor, a storage medium, etc.) or a network of computing devices in the form of hardware, firmware, software, or a combination thereof, which can be achieved by those of ordinary skill in the art using their basic programming skills after reading the description of the present invention.

[0107] Therefore, the object of the present invention can also be achieved by running a program or a set of programs on any computing device. The computing device can be a well-known general device. Therefore, the object of the present invention can also be achieved only by providing a program product containing program codes for implementing the method or device. That is to say, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be noted that in the device and method of the present invention, obviously, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present invention. And, the steps of performing the above series of processes can naturally be executed in chronological order according to the described order, but it is not necessary to execute them in chronological order. Some steps can be executed in parallel or independently of each other.

[0108] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for nuclear criticality safety calculation of uranium solution, characterized in that, Including: Obtain the material parameters and geometric parameters in the uranium solution system; The uranium solution system is a dissolver containing uranium solution; The uranium enrichment of the uranium solution is less than 20%; Construct a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods; Calculate the effective neutron multiplication factor of the uranium solution system through the lattice model; Wherein, the lattice model is an array formed by uniformly distributing a plurality of nuclear fuel rods in a moderator, and the plurality of nuclear fuel rods are uranium dioxide nuclear fuel rods; Wherein, constructing a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods includes: Obtain the spacing between uranium dioxide nuclear fuel rods in the lattice model and the radius of the uranium dioxide nuclear fuel rods according to the infinite neutron multiplication factor of the uranium solution system; Obtain the effective neutron multiplication factors of the uranium dioxide nuclear fuel rods at multiple different preset radii according to the rod spacing between the uranium dioxide nuclear fuel rods; Obtain a first curve graph of the rod spacing and the effective neutron multiplication factor, and a second curve graph of the radius of the uranium dioxide nuclear fuel rod and the effective neutron multiplication factor according to the effective neutron multiplication factor, the rod spacing between the uranium dioxide nuclear fuel rods and the radius of the uranium dioxide nuclear fuel rods; Determine that the extreme values in the first curve graph and the second curve graph are the target rod spacing and the target nuclear fuel rod radius of the lattice model; Wherein, calculating the effective neutron multiplication factor of the uranium solution system through the lattice model includes: According to the formula: , calculate the effective neutron multiplication factor of the uranium solution system, where is the neutron non-leakage rate during the moderation process, is the non-leakage rate of thermal neutrons during the diffusion process, is the resonance escape probability, is the thermal neutron utilization factor, is the number of effective fission neutrons, is the fast neutron multiplication factor.

2. The method for nuclear criticality safety calculation of uranium solution according to claim 1, characterized in that, The lattice model is located in a hanging basket in the uranium solution system.

3. The method for nuclear criticality safety calculation of uranium solution according to claim 1, characterized in that The uranium dioxide nuclear fuel rods are cylinders, and in the array formed by the plurality of uranium dioxide nuclear fuel rods and the moderator, any three adjacent nuclear fuel rods are distributed in an equilateral triangle.

4. The method for calculating the nuclear critical safety of uranium solution according to claim1, wherein The material parameters include: 235 U and 238 the abundance of U, the density of uranium dioxide in the uranium solution system, the materials and densities of the moderator and reflector in the uranium solution system; The geometric parameters include: the length and radius of the uranium dioxide nuclear fuel rods in the lattice model, the rod spacing between two adjacent uranium dioxide nuclear fuel rods, the size and material of the container.

5. The method for nuclear criticality safety calculation of uranium solution according to claim 4, characterized in that, Both the moderator and the reflector are water.

6. A device for nuclear criticality safety calculation of uranium solution, characterized in that, Including: An acquisition module for acquiring the material parameters and geometric parameters in the uranium solution system; The uranium solution system is a dissolver containing uranium solution; A processing module for constructing a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods; performing calculations on the uranium solution system through the lattice model, and obtaining the calculation result of the effective neutron multiplication factor of the uranium solution system; Wherein, the lattice model is an array formed by uniformly distributing a plurality of nuclear fuel rods in a moderator, and the plurality of nuclear fuel rods are uranium dioxide nuclear fuel rods; Wherein, constructing a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods includes: Obtain the spacing between uranium dioxide nuclear fuel rods in the lattice model and the radius of the uranium dioxide nuclear fuel rods according to the infinite neutron multiplication factor of the uranium solution system; Obtain the effective neutron multiplication factors of the uranium dioxide nuclear fuel rods at multiple different preset radii according to the rod spacing between the uranium dioxide nuclear fuel rods; Obtain a first curve graph of the rod pitch and the effective neutron multiplication factor, and a second curve graph of the radius of the uranium dioxide nuclear fuel rod and the effective neutron multiplication factor according to the effective neutron multiplication factor, the rod pitch between the uranium dioxide nuclear fuel rods, and the radius of the uranium dioxide nuclear fuel rod; Determine that the extreme values in the first curve graph and the second curve graph are the target rod pitch and the target nuclear fuel rod radius of the lattice model; Wherein, calculating the effective neutron multiplication factor of the uranium solution system through the lattice model includes: According to the formula: , calculate the effective neutron multiplication factor of the uranium solution system, where is the neutron non-leakage rate during the moderation process, is the non-leakage rate of thermal neutrons during the diffusion process, is the probability of escaping resonance capture, is the thermal neutron utilization factor, is the number of effective fission neutrons, is the fast neutron multiplication factor.

7. A computing device, characterized in that, It includes a processor, a memory, and a program or instruction stored on the memory and executable on the processor. When the program or instruction is executed by the processor, the method described in any one of claims 1-5 is implemented.

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