Calculation method, analyzer, and program
The method addresses the inapplicability of PWR-focused calculations in high-temperature gas reactors by employing super-detailed group and equivalence principle calculations, achieving precise and efficient cross-sectional area determination.
Patent Information
- Application Number
- JP2024008100
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-23
- Publication Date
- 2025-08-04
AI Technical Summary
Existing methods for calculating effective cross-sectional areas in high-temperature gas-cooled reactors are not applicable, as they are specialized for Pressurized Water Reactors (PWRs) and do not account for the unique neutron behavior in high-temperature gas-cooled reactors.
A calculation method and analysis device that perform resonance calculations using super-detailed group calculations for energy regions above 20 eV to 100 eV and equivalence principle for lower energy regions, incorporating the influence of upward scattering in high-temperature gas reactors.
Enables accurate and efficient calculation of effective cross-sectional areas in high-temperature gas reactors, balancing precision and calculation load by restricting ultra-detailed group calculations to regions where upward scattering is negligible.
Smart Images
Figure 2025113775000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a calculation method, an analysis device, and a program. [Background technology]
[0002] Non-Patent Document 1 discloses that in the core design of a PWR (Pressurized Water Reactor), among the energy regions where resonance occurs, effective cross sections are calculated using ultra-fine group resonance calculations for relatively high energy regions (regions above 0.625 eV), and for low energy regions (regions below 0.625 eV), resonance calculations using the equivalence principle are performed to calculate effective cross sections. [Prior art documents] [Non-patent literature]
[0003] [Non-Patent Document 1] "Ultra-fine-group resonance treatment using equivalent Dancoff-factor cell model in lattice physics code GALAXY", [Online], Journal of Nuclear Science and Technology Vol 55, Issue 7 2018, [Retrieved January 12, 2024], Internet<https: / / www.tandfonline.com / doi / full / 10.1080 / 00223131.2018.<1439416> Summary of the Invention [Problem to be solved by the invention]
[0004] The method in Non-Patent Document 1 is specialized for PWRs, and cannot be used when designing the core of a high-temperature gas-cooled reactor. A calculation method for the effective cross section suitable for high-temperature gas-cooled reactors is required.
[0005] The present disclosure provides a calculation method, an analysis device, and a program capable of solving the above problems.
Means for Solving the Problems
[0006] The calculation method of the present disclosure is a calculation method for calculating the effective cross-sectional area of a high-temperature gas reactor executed by a computer. In the energy region where resonance occurs among all the energy regions of neutrons in the core of the high-temperature gas reactor, resonance calculation using super-detailed group calculation is performed for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, and resonance calculation using the equivalence principle is performed for the low energy region.
[0007] The analysis device of the present disclosure is an analysis device for calculating the effective cross-sectional area of a high-temperature gas reactor, and includes means for performing resonance calculation using super-detailed group calculation for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV in the energy region where resonance occurs among all the energy regions of neutrons in the core of the high-temperature gas reactor, and performing resonance calculation using the equivalence principle for the low energy region.
[0008] Further, the program of the present disclosure causes a computer to execute a process of calculating the effective cross-sectional area of a high-temperature gas reactor. In the energy region where resonance occurs among all the energy regions of neutrons in the core of the high-temperature gas reactor, resonance calculation using super-detailed group calculation is performed for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, and resonance calculation using the equivalence principle is performed for the low energy region.
Advantages of the Invention
[0009] According to the calculation method, the analysis device, and the program of the present disclosure, the effective cross-sectional area of a high-temperature gas reactor can be calculated with high accuracy and efficiency.
Brief Description of the Drawings
[0010]
Figure 1
Figure 2
Figure 3
Figure 4
Mode for Carrying Out the Invention
[0011] <Embodiment> Hereinafter, the analysis device of the present disclosure will be described with reference to FIGS. 1 to 4. (Configuration) FIG. 1 is a block diagram showing an example of the analysis device according to the embodiment. The analysis device 10 calculates the effective cross-sectional area of a high-temperature gas reactor using graphite as a moderator. Particularly in the region where resonance occurs, resonance calculation using the equivalence principle is performed in a relatively low energy region where upward scattering occurs, and super-detailed group calculation is performed in a relatively high energy region where upward scattering does not occur, thereby calculating the effective cross-sectional area with high precision and efficiency. The analysis device 10 includes an input reception unit 11, a calculation unit 12, an output unit 13, and a storage unit 14.
[0012] The input reception unit 11 receives information, instructions, etc. input using input devices such as a keyboard, mouse, touch panel, buttons, etc. For example, the input reception unit 11 receives the input of information necessary for calculating the effective cross-sectional area, such as the arrangement pattern information of fuel, etc. in the reactor core. The input reception unit 11 records the received information in the storage unit 14 or outputs it to the calculation unit 12.
[0013] The calculation unit 12 calculates the effective cross-sectional area of the core of the high-temperature gas reactor. In the resonance calculation for calculating the effective cross-sectional area of the high-temperature gas reactor, in a relatively high energy region where upward scattering can be ignored, the calculation unit 12 performs a super-detailed group calculation using the slowing-down equation, and in a low energy region where upward scattering cannot be ignored, the calculation unit 12 performs a resonance calculation using the equivalence principle. In the case of a high-temperature gas reactor, upward scattering mainly occurs in low-energy neutrons due to the graphite of the moderator. The lower limit value of the energy region where upward scattering can be ignored in the high-temperature gas reactor is approximately in the range of 20 to 100 eV. The reason why there is a width in the lower limit value of the energy region where upward scattering can be ignored is that it varies depending on various conditions. For example, when the temperature of the graphite increases, the lower limit of the energy region where upward scattering can be ignored rises to around 100 eV. In the calculation of the neutron flux using the equivalence principle applied to the low energy region, in order to directly incorporate the effects of upward scattering and resonance interference, a relatively fine group structure of about several hundred groups is used as the multi-group energy structure of the effective cross-sectional area. On the other hand, in the super-detailed group calculation, for example, a group structure of one hundred thousand to several hundred thousand is used. When the effective cross-sectional area is calculated by the super-detailed group calculation, a more detailed group (higher-precision) calculation result can be obtained, but the calculation load increases. In addition, in the super-detailed group calculation, since the slowing-down equation in which it is difficult to consider upward scattering is used, the application range of the super-detailed group calculation is limited to the energy region where upward scattering can be ignored, and for the region where upward scattering cannot be ignored, the calculation of the effective cross-sectional area is performed by the equivalence principle using a relatively fine group structure so that the effect of upward scattering can be incorporated. Thereby, both ensuring the calculation accuracy and reducing the calculation load are achieved.
[0014] The output unit 13 outputs the effective cross-sectional area calculated by the calculation unit 12 to other devices, electronic files, etc. The memory unit 14 stores arrangement pattern information of fuel and the like, such as how control rod blocks, fuel bodies, and graphite blocks are arranged in the core, and how various fuels are arranged in the fuel bodies, various setting information, processing data during calculations, and the like. Further, the memory unit 14 stores a calculation code 100 which is a computer program for calculating an effective cross-sectional area and the like using the equivalence principle, a calculation code 200 which is a computer program for calculating an effective cross-sectional area and the like by ultra-detailed group calculation, and a calculation code 300 which performs a calculation with less approximation and more refined than the ultra-detailed group calculation to calculate an effective cross-sectional area and the like. The calculation code 300 can perform a core calculation considering the influence of upward scattering occurring in the core, and can also perform a core calculation assuming no upward scattering. The calculation codes 100 to 300 are all known calculation codes. In this specification, it is assumed that the calculation codes 100 to 300 are configured such that the calculation of nuclear constants and the core calculation can be executed by giving arrangement pattern information of fuel and the like and various calculation conditions in the high-temperature gas reactor. Note that the calculation code 300 is used to calculate the lower limit value of the energy region where upward scattering can be ignored, but it is not necessary when setting the lower limit value by another method.
[0015] FIG. 2 shows an example of the correspondence between the energy region of neutrons existing in the core of the high-temperature gas reactor and the calculation method. The calculation unit 12 calculates the effective cross-sectional area for the entire region from low energy (for example, 10 -5 eV) to high energy (for example, 20 MeV). As shown in FIG. 2, for the relatively high energy region in the region where resonance occurs in the entire region, that is, the region where upward scattering can be ignored, the calculation unit 12 calculates the effective cross-sectional area by ultra-detailed group calculation using the calculation code 200. The lower limit of the region where upward scattering can be ignored is 20 to 100 eV, and the upper limit is about 5 keV. For other energy regions, the calculation unit 12 calculates the effective cross-sectional area based on the equivalence principle using the calculation code 100. Note that it is difficult to accurately specify the range of the energy region where resonance occurs, and a value of neutron energy (for example, 5 keV) at which non-separable resonance that is difficult to handle by the slowing-down equation is considered not to occur is set as the upper limit to which ultra-detailed group calculation is applied.
[0016] An example of a method for calculating the lower limit value of the region where upward scattering can be ignored will be described. After setting the calculation conditions of the core, the calculation unit 12 performs a core calculation considering upward scattering using the calculation code 300 for a value of a predetermined neutron energy. Next, the calculation unit 12 performs a core calculation using the calculation code 300 for the same neutron energy value assuming no upward scattering. If there is a difference between the calculation results of the two (for example, the effective cross section or the effective multiplication factor), it is determined that upward scattering cannot be ignored in that energy region. In this case, the core calculation is performed in two ways: by changing (increasing) the value of the neutron energy to be calculated, considering upward scattering and assuming no upward scattering. If the difference between the calculation results of the two disappears, it is determined that upward scattering can be ignored in the energy region higher than that energy region. For example, when calculating under certain calculation conditions, if there is a difference of a predetermined threshold value or more between the calculation results considering upward scattering and assuming no upward scattering in the energy region lower than 30 eV, and the difference between the calculation results of the two is less than the threshold value in the energy region of 30 eV or more, the lower limit value of the region where upward scattering can be ignored can be determined to be 30 eV. For example, the values such as 20 eV to 100 eV described above are the results obtained by calculation using the calculation code 300 under various conditions.
[0017] (Operation) Next, the operation of the analysis device 10 will be described with reference to FIG. 3. FIG. 3 is a flowchart showing an example of the calculation process of the effective cross section according to the embodiment. As a premise, arrangement pattern information of fuel and the like is registered in the storage unit 14. First, consider the lower limit value of the energy region where upward scattering can be ignored (step S1). For example, the calculation unit 12 uses the calculation code 300 to calculate the effective cross-sectional area and the effective multiplication factor considering upward scattering, and the calculation results of the effective cross-sectional area and the effective multiplication factor calculated assuming no upward scattering, and searches for the value of neutron energy at which the difference between the two disappears, and the search result may be used as the lower limit value of the energy region where upward scattering can be ignored. Alternatively, the engineer may set the lower limit value (for example, 30 eV) based on their own knowledge and rules of thumb.
[0018] Next, set the upper and lower limits of the energy region for performing ultra-detailed group calculations (step S2). The operator inputs the examination result of the lower limit value of the energy region where upward scattering can be ignored examined in step S1 to the analysis device 10 as the lower limit value of the energy region for performing ultra-detailed group calculations. In addition, the operator inputs a predetermined value (for example, 5 keV) to the analysis device 10 as the upper limit value of the energy region for performing ultra-detailed group calculations. The input reception unit 11 receives the input value and outputs it to the calculation unit 12. The calculation unit 12 sets each value as the upper limit value and the lower limit value of the energy region to which ultra-detailed group calculations are applied.
[0019] Next, the operator instructs the analysis device 10 to calculate the effective cross-sectional area. The input reception unit 11 receives this instruction, and the calculation unit 12 starts calculating the effective cross-sectional area. First, the calculation unit 12 calculates the effective cross-sectional area using the equivalence principle (step S3). For example, the calculation unit 12 uses the calculation code 100 to apply an energy group structure of several hundreds of groups to the entire region from low energy (for example, 10 -5 eV) to high energy (for example, 20 MeV) and calculates the effective cross-sectional area based on the equivalence principle. At this time, in order to ensure the calculation accuracy, the energy group structure may be changed according to the lower limit value set in step S2. For example, the energy groups are divided more finely when the set lower limit value is 100 eV than when it is 30 eV (the number of energy groups is increased when the value is 100 eV compared to when it is 30 eV). The calculation unit 12 records the effective cross-sectional area for each energy group calculated by the calculation code 100 in the storage unit 14.
[0020] Next, the calculation unit 12 performs ultra-detailed group calculations (step S4). For example, the calculation unit 12 uses the calculation code 200 to perform ultra-detailed group resonance calculations using the deceleration equation for the energy region range from the lower limit value to the upper limit value set in step S2. The calculation unit 12 records the effective cross-section for each energy group calculated by the calculation code 200 in the storage unit 14 (overwriting the effective cross-section in the range of the upper limit value to the lower limit value set in step S2).
[0021] Next, the output unit 13 outputs the calculation result (step S5). The output unit 13 outputs the effective cross-section for each energy group recorded in the storage unit 14 to an electronic file or the like. The calculated effective cross-section can be used for core calculations (such as neutron transport calculations).
[0022] (Effect) As described above, according to the present embodiment, the effective cross-section of the high-temperature gas reactor can be calculated with high precision and efficiency (with a small calculation load and in a short time). Specifically, for the energy region where resonance does not occur, the effective cross-section is calculated based on the equivalence principle. Among the energy regions where resonance occurs, for the energy region where upward scattering cannot be ignored, resonance calculations that incorporate the influence of upward scattering are performed by performing resonance calculations based on the equivalence principle. For the energy region where upward scattering can be ignored, highly accurate calculations are performed by ultra-detailed group calculations. Thereby, the calculation accuracy of the effective cross-section can be maintained. Also, by restricting the application range of the ultra-detailed group calculations with a high calculation load to the energy region where upward scattering can be ignored, the overall calculation load can be reduced. Thereby, the effective cross-section can be calculated in a short time with a small calculation load.
[0023] FIG. 4 is a diagram showing an example of the hardware configuration of the analysis device. The computer 900 includes a CPU 901, a main memory device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The above-described analysis device 10 is implemented in the computer 900. And each of the above functions is stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903, expands it in the main memory device 902, and executes the above processing according to the program. Also, the CPU 901 secures a storage area in the main memory device 902 according to the program. Further, the CPU 901 secures a storage area in the auxiliary storage device 903 for storing the data being processed according to the program.
[0024] Note that a program for realizing all or part of the functions of the analysis device 10 may be recorded on a computer-readable recording medium, the program recorded on this recording medium may be read into a computer system and executed, thereby performing the processing by each functional unit. Here, the "computer system" shall include hardware such as an OS and peripheral devices. Also, the "computer system" shall include a homepage providing environment (or display environment) if it uses a WWW system. Also, the "computer-readable recording medium" refers to a portable medium such as a CD, DVD, USB, etc., and a storage device such as a hard disk built into a computer system. Also, when this program is distributed to the computer 900 via a communication line, the receiving computer 900 may expand the program in the main memory device 902 and execute the above processing. Also, the above program may be for realizing a part of the above-described functions, and may further be realizable in combination with a program already recorded in the computer system for the above-described functions.
[0025] As described above, although some embodiments according to the present disclosure have been described, all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.
[0026] <Appendix> The calculation method, analysis device, and program described in the embodiments are understood as follows, for example.
[0027] (1) The calculation method according to the first aspect is a calculation method for calculating the effective cross-sectional area of a high-temperature gas reactor executed by a computer. In the energy region where resonance occurs among all the energy regions of neutrons in the core of the high-temperature gas reactor, for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, resonance calculation using ultra-detailed group calculation is performed to calculate the effective cross-sectional area, and for the low energy region, resonance calculation using the equivalence principle is performed to calculate the effective cross-sectional area. Thereby, the effective cross-sectional area of the high-temperature gas reactor can be calculated with high accuracy and efficiency.
[0028] (2) The calculation method according to the second aspect is the calculation method of (1). The first effective cross-sectional area is calculated by considering upscattering for a value of a predetermined neutron energy, the second effective cross-sectional area is calculated assuming no upscattering for the value of the neutron energy, and when the difference between the first effective cross-sectional area and the second effective cross-sectional area is equal to or greater than a predetermined threshold value, it is determined that upscattering occurs at the value of the neutron energy, and when the difference is less than the threshold value, it is determined that upscattering does not occur at the value of the neutron energy. This process is performed for a range of values of the predetermined neutron energy, and the lower limit value of the value of the neutron energy determined not to have upscattering is set as the predetermined lower limit value. Thereby, the lower limit value of the range to which ultra-detailed group calculation is applied can be calculated.
[0029] (3) The analysis device according to the third aspect is an analysis device that calculates the effective cross-sectional area of a high-temperature gas furnace, and in the energy region where resonance occurs among all the energy regions of neutrons in the core of the high-temperature gas furnace, for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, resonance calculation using ultra-detailed group calculation is performed to calculate the effective cross-sectional area, and for the low energy region, resonance calculation using the equivalence principle is performed to calculate the effective cross-sectional area, and comprises means for calculating the effective cross-sectional area.
[0030] (4) The program according to the fourth aspect causes a computer to perform a process of calculating the effective cross-sectional area of a high-temperature gas furnace, and in the energy region where resonance occurs among all the energy regions of neutrons in the core of the high-temperature gas furnace, in the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, resonance calculation using ultra-detailed group calculation is performed, and in the low energy region, resonance calculation using the equivalence principle is performed.
Explanation of symbols
[0031] 10 ··· Analysis device 11 ··· Input reception unit 12 ··· Calculation unit 13 ··· Output unit 14 ··· Storage unit 100, 200, 300 ··· Calculation code 900 ··· Computer 901 ··· CPU 902 ··· Main memory device 903 ··· Auxiliary storage device 904 ··· Input / output interface 905 ··· Communication interface
Claims
1. A calculation method for calculating the effective cross-sectional area of a high-temperature gas reactor executed by a computer, in the total energy region of neutrons in the core of the high-temperature gas reactor, for the energy region where resonance occurs, for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, perform resonance calculation using ultra-detailed group calculation to calculate the effective cross-sectional area, and for the lower energy region, perform resonance calculation using the equivalence principle to calculate the effective cross-sectional area, Calculation method.
2. Calculate the first effective cross-sectional area considering upward scattering for a value of a predetermined neutron energy, calculate the second effective cross-sectional area assuming no upward scattering for the value of the neutron energy, and when the difference between the first effective cross-sectional area and the second effective cross-sectional area is equal to or greater than a predetermined threshold value, it is determined that upward scattering occurs at the value of the neutron energy, and when the difference is less than the threshold value, it is determined that upward scattering does not occur at the value of the neutron energy. Perform this process while changing the value of the neutron energy for a predetermined range of the value of the neutron energy, and set the lower limit value of the value of the neutron energy for which it is determined that upward scattering does not occur as the predetermined lower limit value. The calculation method according to claim 1.
3. An analysis device for calculating the effective cross-sectional area of a high-temperature gas reactor, in the total energy region of neutrons in the core of the high-temperature gas reactor, for the energy region where resonance occurs, for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, means for performing resonance calculation using ultra-detailed group calculation to calculate the effective cross-sectional area, and for the lower energy region, means for performing resonance calculation using the equivalence principle to calculate the effective cross-sectional area, Analysis device comprising the same.
4. A program for causing a computer to execute a process for calculating the effective cross-sectional area of a high-temperature gas reactor, in the total energy region of neutrons in the core of the high-temperature gas reactor, for the energy region where resonance occurs, for the energy region higher than a predetermined lower limit value set in the range of 20 eV to 100 eV, perform resonance calculation using ultra-detailed group calculation to calculate the effective cross-sectional area, and for the lower energy region, perform resonance calculation using the equivalence principle to calculate the effective cross-sectional area, Program.