Fuel loading structure, fuel management method and system for reactor core balance circulation

Abstract

The invention discloses a fuel loading structure of a reactor core balance cycle, a fuel management method and system and a computer storage medium, the fuel loading structure of the reactor core balance cycle comprises N1 first new fuel assemblies with the enrichment degree of 4.95% and N2 second new fuel assemblies with the enrichment degree of 4.45%, and N1 and N2 are related to the cycle length grade of the balance cycle; in the radial direction of the reactor core, the N1 first new fuel assemblies, the N2 second new fuel assemblies and the old fuel assemblies are mutually crossed and permeated, and the N1 first new fuel assemblies are arranged on the peripheries of the N2 second new fuel assemblies; the N1 first new fuel assemblies are in central symmetry in pairs relative to the original point of the reactor core; and the N2 second new fuel assemblies are in central symmetry in pairs relative to the original point of the reactor core. According to the technical scheme, not only is the circulation length flexible enough, but also the number of the new fuel assemblies entering the pile can be reduced, the discharging burnup is improved, and the economical efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of nuclear power technology, and in particular to a fuel loading structure, a fuel management method, a system and a computer storage medium for a core balance cycle. Background Art

[0002] The core refueling mode of a nuclear power plant enters the balancing cycle from the 4th cycle, and the core refueling of the balancing cycle is carried out in the "in-out" mode. In addition, the current fuel loading scheme has only four cycle lengths of 445, 490, 510 and 530 days, and for a certain nuclear power unit, each balancing cycle uses the same cycle length.

[0003] Considering the power grid environment where nuclear power plants are located and the best time requirements for overhaul (generally, overhaul is scheduled during the Spring Festival or National Day load trough period), the shortest cycle length is 445 days. Therefore, in some cases (such as when the load factor of nuclear power units is low), even if the shortest cycle length (445 days) is used, if the overhaul and fuel replacement are carried out during the Spring Festival or National Day, the reactor can only be shut down in advance, which will lead to the abandonment of fuel. Therefore, the fuel management strategy adopted by existing nuclear power units is not flexible enough and cannot meet the needs of various overhaul windows. It can only be forced to adopt long-term extended operation or abandon fuel and shut down in advance, affecting the power supply and unit operation safety. Summary of the invention

[0004] The technical problem to be solved by the present application is that, in view of the technical defect that the existing fuel management strategy in the prior art cannot meet the needs of various overhaul windows, a fuel loading structure, a fuel management method, a system and a computer storage medium for a core balance cycle are provided.

[0005] The technical solution adopted by the present application to solve its technical problems is: constructing a fuel loading structure for a core balance cycle, including old fuel assemblies, and also including N1 first new fuel assemblies with an enrichment degree of 4.95% and N2 second new fuel assemblies with an enrichment degree of 4.45%, wherein N1 and N2 are natural numbers, respectively, and are related to the cycle length level of the balance cycle; and, in the radial direction of the core, the N1 first new fuel assemblies, the N2 second new fuel assemblies and the old fuel assemblies cross-penetrate each other, and the N1 first new fuel assemblies are arranged on the periphery of the N2 second new fuel assemblies; the N1 first new fuel assemblies are centrally symmetrical with respect to the core origin; and the N2 second new fuel assemblies are centrally symmetrical with respect to the core origin.

[0006] Preferably, when the core is 157 cores and the cycle length level is 420 days, N1 is 20 and N2 is 36, wherein,

[0007] The loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column;

[0008] The loading positions of the 36 second new fuel assemblies are respectively: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 7th row P column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 9th row B column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, and 14th row G column.

[0009] Preferably, when the core is 157 cores and the cycle length level is 440 days, N1 is 20, N2 is 40, wherein,

[0010] The loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column;

[0011] The loading positions of the 40 second new fuel assemblies are respectively: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 4th row K column, 4th row F column, 5th row J column, 5th row G column, 6th row M column, 6th row D column, 7th row P column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 9th row B column, 10th row M column, 10th row D column, 11th row J column, 11th row G column, 12th row K column, 12th row F column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, and 14th row G column.

[0012] Preferably, when the core is 157 cores and the cycle length level is 490 days, N1 is 20 and N2 is 44, wherein,

[0013] The loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column;

[0014] The loading positions of the 44 second new fuel assemblies are: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 4th row K column, 4th row F column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 6th row M column, 6th row H column, 6th row D column, 7th row P column, 7th row N column, 7th row L column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row Column K, 8th row F column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row E column, 9th row C column, 9th row B column, 10th row M column, 10th row H column, 10th row D column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 12th row K column, 12th row F column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, 14th row G column.

[0015] Preferably, when the core is 157 cores and the cycle length level is 510 days, N1 is 20 and N2 is 48, wherein,

[0016] The loading positions of the 20 first new fuel assemblies are: 2nd row J column, 2nd row G column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 7th row P column, 7th row B column, 9th row P column, 9th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row J column, 14th row G column;

[0017] The loading positions of the 48 second new fuel assemblies are: 2nd row H column, 3rd row K column, 3rd row J column, 3rd row G column, 3rd row F column, 4th row L column, 4th row E column, 5th row M column, 5th row J column, 5th row G column, 5th row D column, 6th row N column, 6th row K column, 6th row H column, 6th row F column, 6th row C column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 8th row P column, 8th row K column 14th row, 15th row, 16th row, 17th row, 18th row, 19th row, 20th row, 21st row, 22nd row, 23rd row, 24th row, 25th row, 26th row, 27th row, 28th row, 29th row, 30th row, 31st row, 32nd row, 33rd row, 34th row, 35th row, 36th row, 37th row, 38th row, 39th row, 40th row, 41st row, 42nd row, 43rd row, 44th row, 45th row, 46th row, 47th row, 48th row, 49th row, 50th row, 51st row, 52nd row, 53rd row, 54th row, 55th row, 56th row, 57th row, 58th row,

[0018] Preferably, when the core is 157 cores and the cycle length level is 530 days, N1 is 20 and N2 is 52, wherein,

[0019] The loading positions of the 20 first new fuel assemblies are: 2nd row J column, 2nd row G column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 7th row P column, 7th row B column, 9th row P column, 9th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row J column, 14th row G column;

[0020] The loading positions of the 52 second new fuel assemblies are: 2nd row H column, 3rd row K column, 3rd row J column, 3rd row G column, 3rd row F column, 4th row K column, 4th row F column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 6th row N column, 6th row M column, 6th row K column, 6th row H column, 6th row F column, 6th row D column, 6th row C column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 8th row P column, 8th row K column , 8th row F column, 8th row B column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 10th row N column, 10th row M column, 10th row K column, 10th row H column, 10th row F column, 10th row D column, 10th row C column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 12th row K column, 12th row F column, 13th row K column, 13th row J column, 13th row G column, 13th row F column, 14th row H column.

[0021] The present invention also provides a fuel management method for a core balance cycle, comprising:

[0022] Step S10, determining the cycle length level corresponding to each overhaul according to the overhaul plan information of the nuclear power unit;

[0023] Step S20, for each overhaul, the number N1 and loading positions of the first new fuel assemblies with an enrichment of 4.95%, and the number N2 and loading positions of the second new fuel assemblies with an enrichment of 4.45% are determined according to the determined cycle length level, so as to obtain the fuel loading structure of the overhaul, wherein N1 and N2 are natural numbers, respectively, and are related to the determined cycle length level; and, in the radial direction of the core, N1 of the first new fuel assemblies, N2 of the second new fuel assemblies and the old fuel assemblies cross-penetrate each other, and the N1 of the first new fuel assemblies are arranged on the periphery of the N2 of the second new fuel assemblies; the N1 of the first new fuel assemblies are centrally symmetrical with respect to the core origin; and the N2 of the second new fuel assemblies are centrally symmetrical with respect to the core origin;

[0024] Step S30, simulating and analyzing the fuel loading structure of each overhaul, and determining whether corresponding preset conditions are met;

[0025] Step S40, when the corresponding preset conditions are met, the fuel loading structure determined in step S20 is used as the final fuel loading structure, and when performing the corresponding overhaul, the fuel assembly is replaced according to the corresponding final fuel loading structure.

[0026] Preferably, it also includes:

[0027] When the corresponding preset conditions are met, step S20 is re-executed to redetermine the fuel loading structure.

[0028] The present invention also constructs a computer storage medium storing a computer program, which implements the steps of the fuel management method for the core balance cycle described above when executed by a processor.

[0029] The present invention also constructs a fuel management system for a core balancing cycle, comprising a processor and a memory storing a computer program, wherein the processor implements the steps of the above-mentioned fuel management method for a core balancing cycle when executing the computer program.

[0030] In the technical solution of the present application, a fuel loading structure for the core balance cycle of a nuclear power unit is designed by using two types of fuel assemblies with enrichment of 4.45% + 4.95%, which not only makes the cycle length flexible enough to match the demand of placing the overhaul window on the National Day and the Spring Festival under different load factors of the power plant, but also breaks through the lower limit of the original cycle length and solves the problem of large-scale discarding of materials under low load factors. Moreover, by introducing a fuel assembly with an enrichment of 4.95%, compared with the current fuel loading scheme of a single fuel assembly with an enrichment of 4.45%, the number of new fuel assemblies entering the stack can be reduced, the fuel consumption of unloading can be increased, and the economy can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0032] Figure 1 It is a structural schematic diagram of a first embodiment of a fuel loading structure of a core balance cycle of the present invention;

[0033] Figure 2 It is a structural schematic diagram of a second embodiment of the fuel loading structure of the core balance cycle of the present invention;

[0034] Figure 3 It is a structural schematic diagram of a third embodiment of the fuel loading structure of the core balance cycle of the present invention;

[0035] Figure 4 It is a structural schematic diagram of a fourth embodiment of the fuel loading structure of the core balance cycle of the present invention;

[0036] Figure 5 2 is a schematic structural diagram of a fifth embodiment of a fuel loading structure for a core balance cycle of the present invention;

[0037] Figure 6 It is a flow chart of Example 1 of the fuel management method for the core balance cycle of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] The present invention constructs a fuel loading structure for a core balance cycle, which includes an old fuel assembly, N1 first new fuel assemblies with an enrichment degree of 4.95%, and N2 second new fuel assemblies with an enrichment degree of 4.45%, wherein N1 and N2 are natural numbers, respectively, and are related to the cycle length level of the balance cycle. Moreover, in the radial direction of the core, the N1 first new fuel assemblies, the N2 second new fuel assemblies and the old fuel assemblies intersect and penetrate each other, and the N1 first new fuel assemblies are arranged on the periphery of the N2 second new fuel assemblies; the N1 first new fuel assemblies are centrally symmetrical with respect to the core origin; and the N2 second new fuel assemblies are centrally symmetrical with respect to the core origin.

[0040] In the technical solution of this embodiment, a fuel loading structure for a nuclear power unit core balance cycle is designed using two types of fuel assemblies with enrichments of 4.45% + 4.95%, which not only makes the cycle length flexible enough to match the demand of placing the overhaul window on the National Day and the Spring Festival under different load factors of the power plant, but also breaks through the lower limit of the original cycle length and solves the problem of large-scale discarding of materials under low load factors. Moreover, by introducing a fuel assembly with an enrichment of 4.95%, compared with the current fuel loading scheme of a single fuel assembly with an enrichment of 4.45%, the number of new fuel assemblies entering the stack can be reduced, the fuel consumption of unloading can be increased, and the economy can be improved.

[0041] Figure 11 is a schematic diagram of the structure of the fuel loading structure of the core balance cycle of the present invention. In this embodiment, the core is a 157 core, that is, the 157 core has 15 rows (rows 1-15) and 15 columns (columns A-R). The cycle length level is 420 days, N1 is 20, and N2 is 36. At this time, the composition of the fuel assembly of the core is shown in Table 1, wherein N-2 represents the fuel assembly unloaded in the first two cycles of the current cycle, and the long cycle represents the fuel assembly unloaded in the previous cycle.

[0042]

[0043] Table 1

[0044] Combination Figure 1 As shown in Table 1, the loading positions of 20 first new fuel assemblies (new fuel assemblies with an enrichment degree of 4.95%) are respectively: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, and 14th row F column. The loading positions of the 36 second new fuel assemblies (new fuel assemblies with an enrichment degree of 4.45%) are respectively: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 7th row P column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 9th row B column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, and 14th row G column.

[0045] Figure 2 1 is a schematic diagram of the structure of the fuel loading structure of the core balance cycle of the present invention. In this embodiment, when the core is 157 cores and the cycle length level is 440 days (for example, 442 days), N1 is 20, N2 is 40, and the composition of the fuel assembly of the core is as shown in Table 2:

[0046]

[0047] Table 2

[0048] Combination Figure 2As shown in Table 2, the loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column. The loading positions of the 40 second new fuel assemblies are respectively: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 4th row K column, 4th row F column, 5th row J column, 5th row G column, 6th row M column, 6th row D column, 7th row P column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 9th row B column, 10th row M column, 10th row D column, 11th row J column, 11th row G column, 12th row K column, 12th row F column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, and 14th row G column.

[0049] Figure 3 3 is a schematic diagram of the structure of the fuel loading structure of the core balance cycle of the present invention. In this embodiment, when the core is 157 cores and the cycle length level is 490 days (for example, 494 days), N1 is 20, N2 is 44, and the composition of the fuel assembly of the core is as shown in Table 3:

[0050]

[0051] Table 3

[0052] Combination Figure 3 As shown in Table 3, the loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column. The loading positions of the 44 second new fuel assemblies are: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 4th row K column, 4th row F column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 6th row M column, 6th row H column, 6th row D column, 7th row P column, 7th row N column, 7th row L column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row Column K, 8th row F column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row E column, 9th row C column, 9th row B column, 10th row M column, 10th row H column, 10th row D column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 12th row K column, 12th row F column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, 14th row G column.

[0053] Figure 4 4 is a schematic diagram of a fuel loading structure of a core balance cycle of the present invention. In this embodiment, when the core is 157 cores and the cycle length level is 510 days, N1 is 20, N2 is 48, and the composition of the fuel assembly of the core is as shown in Table 4:

[0054]

[0055] Table 4

[0056] Combination Figure 4 As shown in Table 4, the loading positions of the 20 first new fuel assemblies are: 2nd row J column, 2nd row G column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 7th row P column, 7th row B column, 9th row P column, 9th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row J column, and 14th row G column. The loading positions of the 48 second new fuel assemblies are: 2nd row H column, 3rd row K column, 3rd row J column, 3rd row G column, 3rd row F column, 4th row L column, 4th row E column, 5th row M column, 5th row J column, 5th row G column, 5th row D column, 6th row N column, 6th row K column, 6th row H column, 6th row F column, 6th row C column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 8th row P column, 8th row K column 14th row, 15th row, 16th row, 17th row, 18th row, 19th row, 20th row, 21st row, 22nd row, 23rd row, 24th row, 25th row, 26th row, 27th row, 28th row, 29th row, 30th row, 31st row, 32nd row, 33rd row, 34th row, 35th row, 36th row, 37th row, 38th row, 39th row, 40th row, 41st row, 42nd row, 43rd row, 44th row, 45th row, 46th row, 47th row, 48th row, 49th row, 50th row, 51st row, 52nd row, 53rd row, 54th row, 55th row, 56th row, 57th row, 58th row,

[0057] Figure 5 1 is a schematic diagram of the structure of the fuel loading structure of the core balance cycle of the present invention. In this embodiment, when the core is 157 cores and the cycle length level is 530 days, N1 is 20, N2 is 52, and the composition of the fuel assembly of the core is as shown in Table 5:

[0058]

[0059] Table 5

[0060] Combination Figure 5As shown in Table 5, the loading positions of the 20 first new fuel assemblies are: 2nd row J column, 2nd row G column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 7th row P column, 7th row B column, 9th row P column, 9th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row J column, and 14th row G column. The loading positions of the 52 second new fuel assemblies are: 2nd row H column, 3rd row K column, 3rd row J column, 3rd row G column, 3rd row F column, 4th row K column, 4th row F column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 6th row N column, 6th row M column, 6th row K column, 6th row H column, 6th row F column, 6th row D column, 6th row C column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 8th row P column, 8th row K column , 8th row F column, 8th row B column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 10th row N column, 10th row M column, 10th row K column, 10th row H column, 10th row F column, 10th row D column, 10th row C column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 12th row K column, 12th row F column, 13th row K column, 13th row J column, 13th row G column, 13th row F column, 14th row H column.

[0061] Regarding the above embodiment, it should also be noted that for the new fuel assemblies in the balance cycle of the 157 core, 20 new fuel assemblies with a 4.95% enrichment can be fixedly added (the first new fuel assembly) and different numbers (36, 40, 44, 48, 52) of new fuel assemblies with a 4.45% enrichment can be flexibly selected to be added. At the same time, the loading position of each new fuel assembly is determined according to the central symmetry, the cross-penetration of the new and old fuel assemblies, and the arrangement of the first fuel assembly on the periphery of the second fuel assembly, so that the balance cycle of the core has five cycle length levels of 420, 440, 490, 510 and 530 days, and can flexibly match the requirements of placing the overhaul window on the National Day and the Spring Festival under different load factors of the power plant, solving the problem of large-scale abandoned materials under low load factors. Moreover, the introduction of fuel assemblies with a 4.95% enrichment can reduce the number of new fuel assemblies entering the stack, increase the fuel consumption of unloading, and improve economic efficiency.

[0062] Figure 6 1 is a flow chart of a first embodiment of a fuel management method for a core balance cycle of the present invention. The fuel management method of this embodiment includes:

[0063] Step S10, determining the cycle length level corresponding to each overhaul according to the overhaul plan information of the nuclear power unit;

[0064] Step S20, for each overhaul, the number N1 and loading positions of the first new fuel assemblies with an enrichment of 4.95%, and the number N2 and loading positions of the second new fuel assemblies with an enrichment of 4.45% are determined according to the determined cycle length level, so as to obtain the fuel loading structure of the overhaul, wherein N1 and N2 are natural numbers, respectively, and are related to the determined cycle length level; and, in the radial direction of the core, N1 of the first new fuel assemblies, N2 of the second new fuel assemblies and the old fuel assemblies cross-penetrate each other, and the N1 of the first new fuel assemblies are arranged on the periphery of the N2 of the second new fuel assemblies; the N1 of the first new fuel assemblies are centrally symmetrical with respect to the core origin; and the N2 of the second new fuel assemblies are centrally symmetrical with respect to the core origin;

[0065] Step S30, simulating and analyzing the fuel loading structure of each overhaul, and determining whether corresponding preset conditions are met, wherein the preset conditions include, for example, shutdown margin, etc.;

[0066] Step S40, when the corresponding preset conditions are met, the fuel loading structure determined in step S20 is used as the final fuel loading structure, and when performing the corresponding overhaul, the fuel assembly is replaced according to the corresponding final fuel loading structure.

[0067] Furthermore, in an optional embodiment, the fuel management method of the present invention further includes: when corresponding preset conditions are met, re-executing step S20 to redetermine the fuel loading structure.

[0068] The present invention also constructs a computer storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the fuel management method for the core balance cycle described above are implemented.

[0069] The present invention also constructs a fuel management system for a core balancing cycle, which includes a processor and a memory storing a computer program. When the processor executes the computer program, the steps of the fuel management method for the core balancing cycle described above are implemented.

[0070] In the fuel management system of the present invention, by introducing a fuel assembly with a 4.95% enrichment, compared with the current fuel loading scheme of a single 4.45% enrichment assembly, the number of new fuel assemblies entering the stack can be reduced, the fuel consumption during unloading can be increased, the economy can be improved, and the fuel cost can be saved by about 117 million yuan per year. In addition, the invented fuel management system has also broken through the lower limit of the original cycle length, shortening it from the original shortest 445 days to 420 days, solving the problem of large-scale waste under low load factors and improving fuel economy. Since the overhaul window is fixed on National Day and Spring Festival, the shortest cycle length is shortened from 445 days to 420 days, which can reduce waste by 25 days. At the same time, the flexible cycles of five different cycle lengths improve the flexibility of overhaul planning, reduce overhaul overlap, and reduce overhaul costs.

[0071] In summary, the fuel management system of the present invention has the following beneficial effects:

[0072] 1. Economic benefits: Since the overhaul window can be selected during the National Day or Spring Festival, the shortest design cycle length is shortened from 445 days to 420 days, which can reduce waste by 25 days;

[0073] 2. Production efficiency: The flexibility of overhaul planning is improved, which is conducive to the flexible arrangement of overhaul windows;

[0074] 3. Social benefits: It reduces the number of new fuel assemblies entering the reactor, improves resource utilization, reduces spent fuel reprocessing, and is more environmentally friendly.

[0075] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A fuel loading structure for core balance circulation, comprising a used fuel assembly, characterized in that: It also includes N1 first new fuel assemblies with an enrichment degree of 4.95% and N2 second new fuel assemblies with an enrichment degree of 4.45%, wherein N1 and N2 are natural numbers respectively and are related to the cycle length level of the balance cycle; moreover, in the radial direction of the core, the N1 first new fuel assemblies, the N2 second new fuel assemblies and the old fuel assemblies cross-penetrate each other, and the N1 first new fuel assemblies are arranged on the periphery of the N2 second new fuel assemblies; the N1 first new fuel assemblies are centrally symmetrical with respect to the core origin; the N2 second new fuel assemblies are centrally symmetrical with respect to the core origin.

2. The fuel loading structure of the core balance cycle according to claim 1, characterized in that: When the core is 157 cores and the cycle length level is 420 days, N1 is 20 and N2 is 36, wherein, The loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column; The loading positions of the 36 second new fuel assemblies are respectively: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 7th row P column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 9th row B column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, and 14th row G column.

3. The fuel loading structure of the core balance cycle according to claim 1, characterized in that: When the core is 157 cores and the cycle length level is 440 days, N1 is 20 and N2 is 40, wherein, The loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column; The loading positions of the 40 second new fuel assemblies are respectively: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 4th row K column, 4th row F column, 5th row J column, 5th row G column, 6th row M column, 6th row D column, 7th row P column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 9th row B column, 10th row M column, 10th row D column, 11th row J column, 11th row G column, 12th row K column, 12th row F column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, and 14th row G column.

4. The fuel loading structure for core balance cycle according to claim 1, characterized in that: When the core is 157 cores and the cycle length level is 490 days, N1 is 20 and N2 is 44, wherein, The loading positions of the 20 first new fuel assemblies are: 2nd row K column, 2nd row F column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 6th row P column, 6th row B column, 10th row P column, 10th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row K column, 14th row F column; The loading positions of the 44 second new fuel assemblies are: 2nd row J column, 2nd row H column, 2nd row G column, 3rd row J column, 3rd row G column, 4th row K column, 4th row F column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 6th row M column, 6th row H column, 6th row D column, 7th row P column, 7th row N column, 7th row L column, 7th row E column, 7th row C column, 7th row B column, 8th row P column, 8th row Column K, 8th row F column, 8th row B column, 9th row P column, 9th row N column, 9th row L column, 9th row E column, 9th row C column, 9th row B column, 10th row M column, 10th row H column, 10th row D column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 12th row K column, 12th row F column, 13th row J column, 13th row G column, 14th row J column, 14th row H column, 14th row G column.

5. The fuel loading structure for core balance cycle according to claim 1, characterized in that: When the core is 157 cores and the cycle length level is 510 days, N1 is 20 and N2 is 48, wherein, The loading positions of the 20 first new fuel assemblies are: 2nd row J column, 2nd row G column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 7th row P column, 7th row B column, 9th row P column, 9th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row J column, 14th row G column; The loading positions of the 48 second new fuel assemblies are: 2nd row H column, 3rd row K column, 3rd row J column, 3rd row G column, 3rd row F column, 4th row L column, 4th row E column, 5th row M column, 5th row J column, 5th row G column, 5th row D column, 6th row N column, 6th row K column, 6th row H column, 6th row F column, 6th row C column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 8th row P column, 8th row K column 14th row, 15th row, 16th row, 17th row, 18th row, 19th row, 20th row, 21st row, 22nd row, 23rd row, 24th row, 25th row, 26th row, 27th row, 28th row, 29th row, 30th row, 31st row, 32nd row, 33rd row, 34th row, 35th row, 36th row, 37th row, 38th row, 39th row, 40th row, 41st row, 42nd row, 43rd row, 44th row, 45th row, 46th row, 47th row, 48th row, 49th row, 50th row, 51st row, 52nd row, 53rd row, 54th row, 55th row, 56th row, 57th row, 58th row, 6. The fuel loading structure of the core balance cycle according to claim 1, characterized in that: When the core is 157 cores and the cycle length level is 530 days, N1 is 20 and N2 is 52, wherein, The loading positions of the 20 first new fuel assemblies are: 2nd row J column, 2nd row G column, 3rd row L column, 3rd row E column, 4th row M column, 4th row D column, 5th row N column, 5th row C column, 7th row P column, 7th row B column, 9th row P column, 9th row B column, 11th row N column, 11th row C column, 12th row M column, 12th row D column, 13th row L column, 13th row E column, 14th row J column, 14th row G column; The loading positions of the 52 second new fuel assemblies are: 2nd row H column, 3rd row K column, 3rd row J column, 3rd row G column, 3rd row F column, 4th row K column, 4th row F column, 5th row L column, 5th row J column, 5th row G column, 5th row E column, 6th row N column, 6th row M column, 6th row K column, 6th row H column, 6th row F column, 6th row D column, 6th row C column, 7th row N column, 7th row L column, 7th row J column, 7th row G column, 7th row E column, 7th row C column, 8th row P column, 8th row K column , 8th row F column, 8th row B column, 9th row N column, 9th row L column, 9th row J column, 9th row G column, 9th row E column, 9th row C column, 10th row N column, 10th row M column, 10th row K column, 10th row H column, 10th row F column, 10th row D column, 10th row C column, 11th row L column, 11th row J column, 11th row G column, 11th row E column, 12th row K column, 12th row F column, 13th row K column, 13th row J column, 13th row G column, 13th row F column, 14th row H column.

7. A fuel management method for a core balance cycle, characterized in that: include: Step S10, determining the cycle length level corresponding to each overhaul according to the overhaul plan information of the nuclear power unit; Step S20, for each overhaul, the number N1 and loading positions of the first new fuel assemblies with an enrichment of 4.95%, and the number N2 and loading positions of the second new fuel assemblies with an enrichment of 4.45% are determined according to the determined cycle length level, so as to obtain the fuel loading structure of the overhaul, wherein N1 and N2 are natural numbers, respectively, and are related to the determined cycle length level; and, in the radial direction of the core, N1 of the first new fuel assemblies, N2 of the second new fuel assemblies and the old fuel assemblies cross-penetrate each other, and the N1 of the first new fuel assemblies are arranged on the periphery of the N2 of the second new fuel assemblies; the N1 of the first new fuel assemblies are centrally symmetrical with respect to the core origin; and the N2 of the second new fuel assemblies are centrally symmetrical with respect to the core origin; Step S30, simulating and analyzing the fuel loading structure of each overhaul, and determining whether corresponding preset conditions are met; Step S40, when the corresponding preset conditions are met, the fuel loading structure determined in step S20 is used as the final fuel loading structure, and when performing the corresponding overhaul, the fuel assembly is replaced according to the corresponding final fuel loading structure.

8. The fuel management method for core balancing cycle according to claim 7, characterized in that: Also includes: When the corresponding preset conditions are met, step S20 is re-executed to redetermine the fuel loading structure.

9. A computer storage medium storing a computer program, characterized in that: The computer program implements the steps of the fuel management method for the core balancing cycle of claim 7 or 8 when executed by a processor.

10. A fuel management system for a core balance cycle, comprising a processor and a memory storing a computer program, characterized in that: When executing the computer program, the processor implements the steps of the fuel management method for the core balancing cycle of claim 7 or 8.

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