Control rod rearrangement method and system for an operating nuclear power plant

Abstract

The present invention relates to a control rod rearrangement method and system for an operating nuclear power plant, the control rod rearrangement method comprising: obtaining radial power distribution information of the core in a new mode and an old mode respectively; comparing the power of the fuel assemblies in each radial region of the core in the new mode with the power in the old mode respectively according to the radial power distribution information; according to the comparison result, exchanging the positions in the core or the functional control logic of at least two control rod groups in different radial regions, so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode. Through this technical solution, the matching and optimization of the control rod functions can be achieved to obtain more operation and safety margins.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power design, and in particular to a control rod rearrangement method and system for an operating nuclear power plant. Background Art

[0002] Nuclear reactor core design is one of the key design contents of nuclear power plants. The main task of nuclear reactor core design is to provide a nuclear reactor core that meets the overall design requirements of pressurized water reactor nuclear power plants from the perspective of nuclear reactor physics, including determining the number of fuel assemblies / control rods / detectors, the arrangement of fuel assemblies / control rods / detectors in the nuclear reactor core, etc. Among them, the control rods are made of neutron-absorbing materials and can control the rate of chain reactions at a predetermined level.

[0003] After a nuclear power plant has been operating for multiple cycles (many years), it is modified for some reason (such as fuel management). This modification will affect the power distribution of the power plant core. In this case, if the arrangement of the control rods is not adjusted, the total value of the control rods may be reduced or the power control capability of the control rods may be affected, thereby reducing the safety of the power plant and the ability of the power plant to operate. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the prior art has the defect that the total value of the control rods will be reduced or the power control capability of the control rods will be affected after the core is modified to affect the core power distribution.

[0005] The technical solution adopted by the present invention to solve the technical problem is: construct a control rod rearrangement method for an operating nuclear power plant, comprising:

[0006] Step S10. Obtain radial power distribution information of the core in the new mode and the old mode respectively;

[0007] Step S20. According to the radial power distribution information, the power of the fuel assemblies in each radial region of the core under the new mode is compared with the power under the old mode;

[0008] Step S30. Based on the comparison result, at least two control rod groups in different radial regions are interchanged in position within the core or their functional control logic is interchanged, so that the total value of control rods in the new mode of the core is greater than the total value of control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0009] Preferably, the types of the control rod group include: a black body rod group and a grey body rod group;

[0010] Each radial region of the core includes an outer ring, a middle ring, and an inner ring.

[0011] Preferably, in step S30, if the power of the fuel assembly at the outer ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways:

[0012] Interchange the positions of at least one black body rod group in the outer ring of the core with at least one gray body rod group in the middle ring or inner ring of the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode;

[0013] At least one black body rod group for power control in the outer ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode;

[0014] Exchanging the functional control logic of at least one black body rod group for power control in the outer ring of the core with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode;

[0015] A part of the rod bundles of at least one black body rod group for power control in the outer ring of the core are interchanged with the corresponding rod bundles of at least one gray body rod group in the middle ring or inner ring of the core, and another part of the rod bundles of at least one black body rod group for power control in the outer ring of the core are interchanged with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the total value of the control rods of the core in a new mode is greater than the total value of the control rods in an old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0016] Preferably, in step S30, if the power of the fuel assembly in the inner ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways:

[0017] Interchange the positions of at least one black body rod group in the inner ring of the core with at least one gray body rod group in the middle ring or outer ring of the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode;

[0018] At least one black body rod group for power control in the inner ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode;

[0019] Exchanging the functional control logic of at least one black body rod group for power control in the inner ring of the core with at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode;

[0020] A part of the rod bundles of at least one black body rod group for power control in the inner ring of the core are interchanged with the corresponding rod bundles of at least one gray body rod group in the middle ring or outer ring of the core, and another part of the rod bundles of at least one black body rod group for power control in the inner ring of the core are interchanged with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the total value of the control rods of the core in a new mode is greater than the total value of the control rods in an old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0021] Preferably, the cores include: 121 core, 157 core, 177 core, 193 core, and 241 core.

[0022] Preferably, when the core is a 157 core, step S30 includes:

[0023] If the power of the fuel assembly in the outer ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways:

[0024] The N2 control rod group on the outer ring of the core and the G2 control rod group on the middle ring of the core are interchanged in the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode;

[0025] The N2 control rod group on the outer ring of the core and the SB control rod group on the middle ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode;

[0026] The N2 control rod group on the outer ring of the core and the SD control rod group on the inner ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode;

[0027] Four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the G1 control rod group on the middle ring of the core, and another four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the SC control rod group on the middle ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0028] The present invention constructs a control rod rearrangement system for an operating nuclear power plant, comprising:

[0029] A power acquisition module, used to respectively acquire radial power distribution information of the core in the new mode and the old mode;

[0030] A power comparison module, used for comparing the power of the fuel assemblies in each radial region of the core under the new mode with the power under the old mode according to the radial power distribution information;

[0031] A control rod interchange module is used to interchange the in-core positions of at least two control rod groups in different radial regions or to interchange the functional control logics based on the comparison results, so that the total value of the control rods of the core in a new mode is greater than the total value of the control rods in an old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0032] Preferably, the types of the control rod group include: a black body rod group and a grey body rod group;

[0033] Each radial region of the core includes an outer ring, a middle ring, and an inner ring.

[0034] Preferably, the cores include: 121 core, 157 core, 177 core, 193 core, and 241 core.

[0035] Preferably, the control rod interchange module is used to interchange at least two control rod groups in one of the following ways or a combination of two or more ways when the power of the fuel assembly at the outer ring of the core in the new mode decreases relative to the power in the old mode:

[0036] The N2 control rod group on the outer ring of the core and the G2 control rod group on the middle ring of the core are interchanged in the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode;

[0037] The N2 control rod group on the outer ring of the core and the SB control rod group on the middle ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode;

[0038] The N2 control rod group on the outer ring of the core and the SD control rod group on the inner ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode;

[0039] Four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the G1 control rod group on the middle ring of the core, and another four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the SC control rod group on the middle ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0040] In the technical solution provided by the present invention, when the power distribution of the nuclear power plant core is affected by the core modification (mode change), without changing the original control rod layout position of the nuclear power plant, the various types of control rods of the power plant are rearranged to make the total value of the control rods of the core in the new mode greater than the total value of the control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode, thereby achieving matching and optimization of the control rod functions to obtain more operating and safety margins. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0042] Figure 1 is a flow chart of a control rod rearrangement method for an operating nuclear power plant according to a first embodiment of the present invention;

[0043] Figure 2 is a schematic diagram of radial partitioning of a core in one embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the radial power distribution of the core under the new and old modes;

[0045] Figure 4 It is a logical structure diagram of the first embodiment of the control rod rearrangement system of the operating nuclear power plant according to the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] First of all, in a pressurized water reactor nuclear power plant, control rods are needed to control the rate of the chain reaction at a predetermined level. From a functional point of view, control rods are divided into the following two categories: control rod group and shutdown rod group, and the control rod group can be further divided into power compensation rod group and temperature adjustment rod group. Among them, the power compensation rod group is used to compensate for the change in reactivity when the load changes; the temperature adjustment rod group is used to adjust the average temperature of the core, compensate for the slight change in reactivity and control the axial power distribution; the shutdown rod group is used when the reactor needs to be shut down urgently, and the shutdown rod group and the control rod group are all dropped into the core to ensure the negative reactivity required for the reactor shutdown. In terms of materials, control rods are divided into the following two categories: blackbody rod group (black rods) and gray body rod group (gray rods). Moreover, each bundle of blackbody rod assembly consists of 24 Ag-In-Cd rods, and each bundle of gray body rod assembly consists of 8 Ag-In-Cd rods and 16 stainless steel rods. Since 16 rods in the gray body rod assembly are replaced from the strong neutron absorber Ag-In-Cd material to the weak neutron absorber stainless steel rod, when arranged in the same position in the core, the value of the control rod is usually much smaller than that of the blackbody rod.

[0048] In addition, it should be noted that the value of the control rod (the impact on the core reactivity) is not only related to the material of the control rod assembly, but also to the power of the fuel assembly at the corresponding position. Moreover, for a certain control rod, the value Δρ of the control rod at that position is approximately related to the power of the fuel assembly at that position as follows:

[0049] Δρ∝Δ(P / kΣf) 2

[0050] Where P is the average power of the fuel assembly at that position; kΣf is the unit fission energy * fission cross section.

[0051] Moreover, according to the neutron value theory of reactor physics, the value of the control rod is proportional to the square of the neutron flux density Φ 2 Approximately proportional.

[0052] Before the operation of a nuclear power plant, the type of control rods and their arrangement in the core are initially designed so that the control rods can control the chain reaction according to this arrangement structure when the core is in operation. After the nuclear power plant has been in operation for many years, if the core is modified to affect the power distribution of the nuclear power plant core (for example, the fuel management mode is modified), the arrangement of various types of control rods in the nuclear power plant can be matched to the impact of such changes, so as to achieve the optimal design and use of control rods under the new mode.

[0053] Figure 1 1 is a flow chart of a control rod rearrangement method for an operating nuclear power plant according to a first embodiment of the present invention. The control rod rearrangement method of this embodiment comprises the following steps:

[0054] Step S10. Obtain radial power distribution information of the core in the new mode and the old mode respectively;

[0055] In this step, the power radial distribution information of the core can be obtained through a dedicated nuclear power design software. In addition, the core can be, for example: 121 core, 157 core, 177 core, 193 core, 241 core, etc.

[0056] Step S20. According to the radial power distribution information, the power of the fuel assemblies in each radial region of the core under the new mode is compared with the power under the old mode;

[0057] In this step, with respect to each radial region of the core, the radial region of the core may be divided into a plurality of regions in advance, for example, Figure 2 As shown, the radial region of the core can be divided into an inner ring, a middle ring and an outer ring, that is, each radial region of the core includes: an inner ring Q1, a middle ring Q2, and an outer ring Q3.

[0058] Step S30. Based on the comparison result, at least two control rod groups in different radial regions are interchanged in position within the core or their functional control logic is interchanged, so that the total value of control rods in the new mode of the core is greater than the total value of control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0059] Through the technical solution of this embodiment, when the power distribution of the nuclear power plant core is affected by the core modification (mode change), without changing the original control rod arrangement position of the nuclear power plant, the various types of control rods of the power plant are rearranged to make the total value of the control rods of the core in the new mode greater than the total value of the control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode, thereby achieving matching and optimization of the control rod functions to obtain more operation and safety margins.

[0060] Further, in step S30, if the power of the fuel assembly in the outer ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways:

[0061] Mode 11: at least one black body rod group in the outer ring of the core is exchanged with at least one gray body rod group in the middle ring or inner ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode. In this exchange mode, due to the decrease in the power of the outermost ring fuel assembly, the value of the outermost ring control rods will also decrease. At this time, if it is exchanged with the gray body rods arranged in the middle ring or inner ring of the core, the value of the black body rods will be greatly increased. The value of the gray body rods is originally small, and the decrease in its value after being exchanged to the outermost ring will be less than the increase in the value of the black body rods. Therefore, the total value of all control rod assemblies of the entire core will be increased, and the core shutdown margin provided by the control rod value will also be increased, thereby improving the safety of the power plant.

[0062] Mode 12: At least one black body rod group for power control in the outer ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this exchange mode, due to the power reduction of the outermost ring fuel assembly, the value of its control rod will also decrease significantly. At this time, if it is exchanged with the black body rod arranged in the inner ring or middle ring of the core, since both are black body rods, the total value of all control rod assemblies of the entire core will not change after the exchange, but the value of the control rods used for the power compensation rod group will be increased, which will provide more power control capabilities and improve the ability of power plant operation.

[0063] Mode 13: Interchange the functional control logic of at least one black body rod group for power control in the outer ring of the core with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this interchange mode, referring to the reasons of the above interchange mode 12, although the total value of all control rod assemblies of the entire core does not change after the interchange, the value of the control rods used for the power compensation rod group is increased, which will provide more power control capability and improve the operation capability of the power plant;

[0064] Mode 14: swapping the positions of a part of the rod bundles of at least one black body rod group for power control in the outer ring of the core with the corresponding rod bundles of at least one gray body rod group in the middle ring or inner ring of the core, and swapping the positions of another part of the rod bundles of at least one black body rod group for power control in the outer ring of the core with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this swapping mode, referring to the effects of the above-mentioned swapping modes 11 and 12, the total value of all control rod assemblies of the entire core will be improved to a certain extent, and at the same time, after the value of the control rods used for the power compensation rod group is improved, more power control capability will be provided.

[0065] Further, in step S30, if the power of the fuel assembly in the inner ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways:

[0066] Mode 21. At least one black body rod group in the inner ring of the core is exchanged with at least one gray body rod group in the middle ring or outer ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode. In this exchange mode, due to the decrease in the power of the innermost ring fuel assembly, the value of the innermost ring control rods will also decrease. At this time, if it is exchanged with the gray body rods arranged in the middle ring or outer ring of the core, the value of the black body rod group will be greatly increased. The value of the gray body rods is originally small, and the decrease in its value after being exchanged to the innermost ring will be less than the increase in the value of the black body rods. Therefore, the total value of all control rod assemblies of the entire core will be increased, and the core shutdown margin provided by the control rod value will also be increased, thereby improving the safety of the power plant.

[0067] Mode 22. At least one black body rod group for power control in the inner ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this exchange mode, due to the power reduction of the innermost ring fuel assembly, the value of its control rod will also decrease significantly. At this time, if it is exchanged with the black body rod arranged in the outer ring or middle ring of the core, since both are black body rods, the total value of all control rod assemblies of the entire core will not change after the exchange, but the value of the control rods used for the power compensation rod group will be increased, which will provide more power control capabilities and improve the ability of power plant operation.

[0068] Mode 23: Interchange the functional control logic of at least one black rod group for power control in the inner ring of the core with at least one black rod group for shutdown control in the middle ring or outer ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this interchange mode, referring to the reasons of the above interchange mode 22, although the total value of all control rod assemblies of the entire core does not change after the interchange, the value of the control rods used for the power compensation rod group is increased, which will provide more power control capability and improve the operation capability of the power plant.

[0069] Mode 24: swapping the positions of a part of the rod bundles of at least one black body rod group for power control in the inner ring of the core with the corresponding rod bundles of at least one gray body rod group in the middle ring or outer ring of the core, and swapping the positions of another part of the rod bundles of at least one black body rod group for power control in the inner ring of the core with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this swapping mode, referring to the effects of the above-mentioned swapping modes 21 and 22, the total value of all control rod assemblies of the entire core will be improved to a certain extent, and at the same time, after the value of the control rods used for the power compensation rod group is improved, more power control capability will be provided.

[0070] Figure 2 It is a schematic diagram of radial division of the core in one embodiment of the present invention. In this embodiment, the core is a 157 core. The types of control rods initially designed and their arrangement in the core are shown in the figure, wherein the power compensation rod group includes G1 (4 bundles of gray rods), G2 (8 bundles of gray rods), N1 (8 bundles of black rods), and N2 (8 bundles of black rods); the temperature adjustment rod group is an R rod group consisting of 8 bundles of black rods; the shutdown rod group consists of 25 bundles of black rods: 5 bundles of SA rod groups, 8 bundles of SB rod groups, 4 bundles of SC rod groups, and 8 bundles of SD rod groups. That is, the number of control rod assemblies in the core is 61 bundles, of which there are 49 bundles of black rods (or black rods) and 12 bundles of gray rods (or gray rods). Moreover, the radial area of ​​the 157 core is divided into an inner ring Q1, an intermediate ring Q2, and an outer ring Q3.

[0071] Assume that the nuclear power plant has carried out fuel management transformation to improve the fuel and power plant economy. For example, the initial annual fuel replacement and outside-in (out-in, new fuel assemblies are first arranged in the outer ring of the core during the cycle, and then arranged in the middle or inner ring of the core during subsequent cycles) method is optimized to an 18-month fuel replacement and inside-out (in-out, new fuel assemblies are first arranged in the middle ring or inner ring of the core during the cycle, and then arranged in the outer ring or middle ring of the core during subsequent cycles) method. Before the modification (new fuel assemblies are arranged in an outside-inside manner), due to the high reactivity of the new fuel assemblies, when arranged in the outer ring of the core, the power of the outermost ring assembly is generally around 0.8 (the average value of all core assemblies is 1.0, so the power of the middle ring and inner ring assemblies will generally be greater than 1.0); after the modification (new assemblies are arranged in an inside-outside manner), since the new fuel assemblies are first arranged in the middle ring or inner ring of the core, the power of the outermost ring fuel assemblies will decrease, generally to around 0.4 (since the average value of all core assemblies is 1.0, correspondingly, the power of the middle ring and inner ring assemblies will be higher than the outside-inside manner before the modification). As a result, the radial distribution of the core power of the power plant changed between the inner-middle-outer ring before and after the modification. For example, see Figure 3 The radial power distribution diagram of the core is shown in the figure. The origin of the horizontal axis is the center of the core (corresponding to Figure 2 The horizontal axis represents the radial distance of the core (unit: m), the vertical axis unit is the relative power value, curve L1 represents the radial power of the core (relative power) in the old mode, and curve L2 represents the radial power of the core (relative power) in the new mode.

[0072] If the power of the fuel assemblies in the outer ring of the core in the new mode is lower than that in the old mode, it can be combined with Figure 2 At least two control rod groups are interchanged as follows:

[0073] Mode 31. The N2 control rod group in the outer ring of the core is exchanged with the G2 control rod group in the middle ring of the core, so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode. In this exchange mode, the N2 control rod group (8 bundles of black rods) is originally arranged in the outermost ring. Since the power of the outermost ring fuel assembly will be significantly reduced, the value of its control rods will also be significantly reduced. At this time, if it is exchanged with the G2 control rod group (8 bundles of gray rods) arranged in the middle ring of the core, the value of the N2 control rod group (8 bundles of black rods) will be greatly increased. Since the G2 control rod group (8 bundles of gray rods) is a gray body rod, its value is originally small. After being exchanged to the outermost ring, its value will decrease less than the value increase of the N2 control rod group (8 bundles of black rods). Therefore, the total value of the entire core 61 bundles of control rod assembly will be increased, and then the core shutdown margin provided by the control rod value will also be increased, thereby improving the safety of the power plant.

[0074] Mode 32: The N2 control rod group in the outer ring of the core is exchanged with the SB control rod group in the middle ring of the core for position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode. In this exchange mode, the N2 control rod group (8 bundles of black rods) is originally arranged in the outermost ring. Since the power of the fuel assembly in the outermost ring will be significantly reduced, the value of its control rods will also be significantly reduced. At this time, if it is exchanged with the SB control rod group arranged in the middle ring of the core, the value of the N2 control rod group will be greatly increased. Since the SB control rod group is also a black rod, the total value of the entire core 61 bundle control rod assembly does not change after the exchange. However, after the value of the N2 control rod group used for the power compensation rod group is increased, it will provide more power control capability and improve the operation capability of the power plant. In addition, it should be noted that since both the N2 and SB control rod groups are black rods, they do not need to be exchanged, and only the functional control logic exchange adjustment is performed in the control rod cabinet and the instrumentation and control system.

[0075] Method 33: The N2 control rod group on the outer ring of the core and the SD control rod group on the inner ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this interchange method, referring to the reasons for the interchange method 32 above, the total value of the entire core 61 bundle control rod assembly does not change after the interchange. However, after the value of the N2 control rod group used for the power compensation rod group is increased, more power control capability will be provided, which improves the operation capability of the power plant.

[0076] Method 34: Four of the control rod bundles of the N2 control rod group on the outer ring of the core are exchanged with the G1 control rod group on the middle ring of the core, and the other four control rod bundles of the N2 control rod group on the outer ring of the core are exchanged with the SC control rod group on the middle ring of the core, so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode. In this exchange method, referring to the effects of the above exchange methods 31 and 32, the total value of all control rod assemblies in the entire core will be improved to a certain extent, and at the same time, after the value of the control rods used for the power compensation rod group is improved, more power control capability will be provided.

[0077] It should be understood that there are many ways to exchange, which are not listed one by one. Moreover, the exchange in the example does not involve changes in the control rod drive rod, the relative position of the control rod and the upper grid plate, and the position of the opening of the pressure vessel top cover, but only involves the exchange of the position in the reactor and the adjustment of the control rod cabinet and the instrumentation and control system.

[0078] Figure 4It is a logical structure diagram of the control rod rearrangement system embodiment 1 of the operating nuclear power plant of the present invention. The control rod rearrangement system of this embodiment includes: a power acquisition module 10, a power comparison module 20 and a control rod interchange module 30, wherein the power acquisition module 10 is used to respectively obtain the radial distribution information of the power of the core in the new mode and the old mode; the power comparison module is used to compare the power of the fuel assemblies in each radial area of ​​the core in the new mode with the power in the old mode according to the radial distribution information of the power; the control rod interchange module is used to interchange the positions of at least two control rod groups in different radial areas in the core or interchange the functional control logic according to the comparison result, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0079] Further, the types of control rod groups include: black body rod group, gray body rod group, and of course, other types may also be included. Moreover, the core includes: 121 core, 157 core, 177 core, 193 core, 241 core, etc.

[0080] In a specific embodiment, for a 157 core, each radial region of the core includes: an outer ring, an intermediate ring, and an inner ring. Moreover, the control rod exchange module 30 is used to exchange at least two control rod groups in one of the following ways or a combination of two or more ways when the power of the fuel assembly in the outer ring of the core in the new mode decreases relative to the power in the old mode:

[0081] The N2 control rod group on the outer ring of the core and the G2 control rod group on the middle ring of the core are interchanged in the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode;

[0082] The N2 control rod group on the outer ring of the core and the SB control rod group on the middle ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode;

[0083] The N2 control rod group on the outer ring of the core and the SD control rod group on the inner ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode;

[0084] Four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the G1 control rod group on the middle ring of the core, and another four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the SC control rod group on the middle ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

[0085] In the above embodiment, after the transformation that affects the power distribution of the nuclear power plant core is carried out, through the technical solution of the above embodiment, various types of control rods of the power plant can be rearranged without changing the existing control rod layout of the nuclear power plant, so as to achieve matching and optimization of the control rod functions and obtain more operating and safety margins.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A control rod rearrangement method for an operating nuclear power plant, characterized in that: include: Step S10. Obtain radial power distribution information of the core in the new mode and the old mode respectively; Step S20. According to the radial power distribution information, the power of the fuel assemblies in each radial region of the core under the new mode is compared with the power under the old mode; Step S30. According to the comparison result, at least two control rod groups in different radial regions are interchanged in position or functional control logic, so that the total value of control rods in the core in the new mode is greater than the total value of control rods in the old mode, and / or the power control capability of the core in the new mode is greater than the power control capability in the old mode; The types of control rod groups include: black body rod group and grey body rod group; Each radial region of the core includes: an outer ring, an intermediate ring, and an inner ring; In step S30, if the power of the fuel assembly in the outer ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways: Interchange the positions of at least one black body rod group in the outer ring of the core with at least one gray body rod group in the middle ring or inner ring of the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode; At least one black body rod group for power control in the outer ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode; Exchanging the functional control logic of at least one black body rod group for power control in the outer ring of the core with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode; A part of the rod bundles of at least one black body rod group for power control in the outer ring of the core are interchanged with the corresponding rod bundles of at least one gray body rod group in the middle ring or inner ring of the core, and another part of the rod bundles of at least one black body rod group for power control in the outer ring of the core are interchanged with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the total value of the control rods of the core in a new mode is greater than the total value of the control rods in an old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

2. The control rod rearrangement method of an operating nuclear power plant according to claim 1, characterized in that: In step S30, if the power of the fuel assembly in the inner ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways: Interchange the positions of at least one black body rod group in the inner ring of the core with at least one gray body rod group in the middle ring or outer ring of the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode; At least one black body rod group for power control in the inner ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode; Exchanging the functional control logic of at least one black body rod group for power control in the inner ring of the core with at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode; A part of the rod bundles of at least one black body rod group for power control in the inner ring of the core are interchanged with the corresponding rod bundles of at least one gray body rod group in the middle ring or outer ring of the core, and another part of the rod bundles of at least one black body rod group for power control in the inner ring of the core are interchanged with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or outer ring of the core, so that the total value of the control rods of the core in a new mode is greater than the total value of the control rods in an old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

3. The control rod rearrangement method of an operating nuclear power plant according to claim 1, characterized in that: The cores include: 121 core, 157 core, 177 core, 193 core, and 241 core.

4. The control rod rearrangement method for an operating nuclear power plant according to claim 3, characterized in that: When the core is a 157 core, step S30 includes: If the power of the fuel assembly in the outer ring of the core in the new mode decreases relative to the power in the old mode, at least two control rod groups are interchanged in one of the following ways or a combination of two or more ways: The N2 control rod group on the outer ring of the core and the G2 control rod group on the middle ring of the core are interchanged in the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode; The N2 control rod group on the outer ring of the core and the SB control rod group on the middle ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode; The N2 control rod group on the outer ring of the core and the SD control rod group on the inner ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode; Four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the G1 control rod group on the middle ring of the core, and another four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the SC control rod group on the middle ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

5. A control rod rearrangement system for an operating nuclear power plant, characterized in that: include: A power acquisition module, used to respectively acquire radial power distribution information of the core in the new mode and the old mode; A power comparison module, used for comparing the power of the fuel assemblies in each radial region of the core under the new mode with the power under the old mode according to the radial power distribution information; a control rod interchange module, configured to interchange the positions of at least two control rod groups in different radial regions in the reactor or interchange their functional control logics according to the comparison result, so that the total value of the control rods in the reactor core in the new mode is greater than the total value of the control rods in the old mode, and / or the power control capability of the reactor core in the new mode is greater than the power control capability in the old mode; The types of control rod groups include: black body rod group and grey body rod group; Each radial region of the core includes: an outer ring, an intermediate ring, and an inner ring; The control rod exchange module is used to exchange at least two control rod groups in one of the following ways or a combination of two or more ways when the power of the fuel assembly at the outer ring of the core in the new mode decreases relative to the power in the old mode: Interchange the positions of at least one black body rod group in the outer ring of the core with at least one gray body rod group in the middle ring or inner ring of the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode; At least one black body rod group for power control in the outer ring of the core is exchanged with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode; Exchanging the functional control logic of at least one black body rod group for power control in the outer ring of the core with at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the power control capability of the core in the new mode is greater than the power control capability in the old mode; A part of the rod bundles of at least one black body rod group for power control in the outer ring of the core are interchanged with the corresponding rod bundles of at least one gray body rod group in the middle ring or inner ring of the core, and another part of the rod bundles of at least one black body rod group for power control in the outer ring of the core are interchanged with the corresponding rod bundles of at least one black body rod group for shutdown control in the middle ring or inner ring of the core, so that the total value of the control rods of the core in a new mode is greater than the total value of the control rods in an old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

6. The control rod rearrangement system for an operating nuclear power plant according to claim 5, characterized in that: The cores include: 121 core, 157 core, 177 core, 193 core, and 241 core.

7. The control rod rearrangement system for an operating nuclear power plant according to claim 6, characterized in that: The control rod exchange module is used to exchange at least two control rod groups in one of the following ways or a combination of two or more ways when the power of the fuel assembly in the outer ring of the core in the new mode decreases relative to the power in the old mode: The N2 control rod group on the outer ring of the core and the G2 control rod group on the middle ring of the core are interchanged in the core so that the total value of the control rods in the new mode of the core is greater than the total value of the control rods in the old mode; The N2 control rod group on the outer ring of the core and the SB control rod group on the middle ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode; The N2 control rod group on the outer ring of the core and the SD control rod group on the inner ring of the core are interchanged in position or functional control logic, so that the power control capability of the core in the new mode is greater than that in the old mode; Four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the G1 control rod group on the middle ring of the core, and another four control rod bundles of the N2 control rod group on the outer ring of the core are swapped with the SC control rod group on the middle ring of the core, so that the total value of the control rods of the core in the new mode is greater than the total value of the control rods in the old mode, and the power control capability of the core in the new mode is greater than the power control capability in the old mode.

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