Spent fuel assembly nuclear material accounting method, system, and readable storage medium

Abstract

The present application relates to a kind of spent fuel assembly nuclear material weighing method, system and readable storage medium, the nuclear material weighing method includes: obtaining the initial nominal enrichment of fuel assembly, the type of spent fuel assembly, the burnup value of spent fuel assembly, irradiation duration, decay duration;It is input to the fuel assembly decay heat model established in advance, and obtains the nuclear material mass table exported by fuel assembly decay heat model;Receive the specific nuclide input by user, and from the nuclear material mass table, the mass of specific nuclide generated by unit mass of metal uranium nuclear reaction is inquired;The initial mass of metal uranium of fuel assembly is obtained, and the mass of specific nuclide generated by unit mass of metal uranium nuclear reaction is combined, the mass of uranium-235 in spent fuel assembly, the mass of plutonium-239, the mass of uranium, the mass of plutonium are calculated.Calculation of the mass of nuclear material at any time point from just shutdown time to spent fuel assembly external handling can be realized by the technical scheme, and human error can be reduced.

Description

Technical Field

[0001] This invention relates to the field of nuclear power, and more particularly to a method, system, and readable storage medium for nuclear material balance of spent fuel assemblies. Background Technology

[0002] Low-enriched metallic uranium fuel assemblies, used as fuel in large pressurized water reactor nuclear power plants, undergo complex nuclear fission reactions during reactor core irradiation. The fissile nuclide uranium (U)-235 is consumed, and a large amount of the fissile nuclide uranium-238 is converted into the fissile nuclide plutonium (Pu)-239 before being consumed. After being burned up in the reactor, the fuel assemblies become spent fuel assemblies, containing extremely complex compositions of metallic uranium, metallic plutonium, and their isotopes.

[0003] As nuclear facilities, nuclear power plants are required to implement nuclear material control over items such as uranium-235, materials and articles containing uranium-235, plutonium-239, and materials and articles containing plutonium-239. A nuclear material accounting system and a nuclear material balance measurement system should be established. Nuclear material balance refers to the measurement and calculation of the mass of the core material (uranium-235, plutonium-239, and other isotopes) in spent fuel assemblies to determine the amount of nuclear material currently existing within a designated area.

[0004] Currently, the existing nuclear material balance method is: after obtaining the burnup value BU of spent fuel assemblies... 组件 Subsequently, based on the initial nominal enrichment level and gadolinium rod number of the fuel assembly, the burnup value for the same enrichment level and gadolinium rod number was retrieved from the "Nuclear Consumption and Nuclear Production Table" and found to be BU. i BU i+1 (BU 组件 In [BU] i BU i+1 Mass Mx of uranium or plutonium isotopes between [ ] i Mx i+1 Then, using interpolation, the burnup value of the spent fuel assembly during unloading is calculated to be BU. 组件 The mass of the isotope element x of U or PU is in the range Mx. Using the method described above, the isotopes of uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 are calculated. The sum of these uranium isotopes represents the total amount of metallic uranium, and the sum of these plutonium isotopes represents the total amount of metallic plutonium. However, this method of using tables for lookup and interpolation has the following problems in practical application:

[0005] 1. Existing methods can only calculate the mass of nuclear material at the moment of reactor shutdown, but cannot calculate the mass of nuclear material at the time between the moment of shutdown and the time of offloading and disposal 8 years after cooling;

[0006] 2. Long-term cooling will affect the amount and concentration of nuclear materials in the core of the assembly, and generally the fuel assembly is not shipped out until it has been cooled in the spent fuel pool for 8 years, and the metal uranium, plutonium isotopes, especially short-lived isotopes, will decay over time. For the consumption of short-lived nuclear materials, artificial decay formula calculation is needed, which consumes manpower and has the risk of human error. SUMMARY

[0007] The technical problem solved by the present application is to provide a spent fuel assembly nuclear material calculation method, system and readable storage medium to solve the above-mentioned defects in the prior art.

[0008] The technical solution adopted by the present application to solve its technical problem is: a spent fuel assembly nuclear material calculation method is constructed, comprising:

[0009] Step S10. Obtain the initial nominal enrichment of the fuel assembly, the type of the spent fuel assembly, the burnup value of the spent fuel assembly, the irradiation time, and the decay time;

[0010] Step S20. Input the initial nominal enrichment, the type, the burnup value, the irradiation time, and the decay time into a pre-established fuel assembly decay heat model, and obtain the nuclear material mass table output by the fuel assembly decay heat model, wherein the nuclear material mass table includes the mass of each nuclide generated by the nuclear reaction of unit mass of metal uranium;

[0011] Step S30. Receive a specific nuclide input by a user, and query the mass of the specific nuclide generated by the nuclear reaction of unit mass of metal uranium from the nuclear material mass table, wherein the specific nuclide includes: uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242;

[0012] Step S40. Obtain the initial mass of the metal uranium of the fuel assembly, and calculate the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly according to the initial mass of the metal uranium and the mass of the specific nuclide generated by the nuclear reaction of unit mass of metal uranium.

[0013] Preferably, in the step S10, the burnup value and the irradiation time of the spent fuel assembly are obtained in the following manner:

[0014] Obtain the power monitoring information of the fuel assembly during the operation of the reactor core;

[0015] Obtain the burnup value and the irradiation time of the spent fuel assembly according to the power monitoring information.

[0016] Preferably, the fuel assembly decay heat model comprises a concentration calculation model of each nuclide, and the concentration calculation model comprises the following superimposed: a fission generation term of the corresponding nuclide; a neutron capture generation term of the corresponding nuclide; a radioactive decay generation term of the corresponding nuclide; a fission disappearance term of the corresponding nuclide; a neutron capture disappearance term of the corresponding nuclide; and a radioactive decay term of the corresponding nuclide.

[0017] Preferably, after the step S40, further comprising:

[0018] Step S50. Generating and outputting a nuclear material balance report of the spent fuel assembly according to the calculation result of the step S40.

[0019] Preferably, in the step S30, querying the mass of the specific nuclide generated by nuclear reaction of unit mass of metallic uranium from the nuclear material mass table comprises:

[0020] Querying the mass of the specific nuclide generated by nuclear reaction of unit mass of metallic uranium from the nuclear material mass table by using VBA; and / or,

[0021] In the step S40, calculating the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly comprises:

[0022] Calculating the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly by using VBA.

[0023] Preferably, in the step S40, calculating the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly according to the initial mass of metallic uranium of the fuel assembly and the mass of the specific nuclide generated by nuclear reaction of unit mass of metallic uranium comprises:

[0024] Calculating the product of the initial mass of metallic uranium of the fuel assembly and the mass of uranium-235 generated by nuclear reaction of unit mass of metallic uranium to obtain the mass of uranium-235 in the spent fuel assembly;

[0025] Calculating the product of the initial mass of metallic uranium of the fuel assembly and the mass of plutonium-239 generated by nuclear reaction of unit mass of metallic uranium to obtain the mass of plutonium-239 in the spent fuel assembly;

[0026] Calculating the sum of the mass of uranium-234, uranium-235, uranium-236, and uranium-238 generated by nuclear reaction of unit mass of metallic uranium, and calculating the product of the initial mass of metallic uranium of the fuel assembly and the sum of the mass of uranium-234, uranium-235, uranium-236, and uranium-238 to obtain the mass of uranium in the spent fuel assembly;

[0027] The mass of the plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 produced by the nuclear reaction of the unit mass of the metallic uranium is calculated, and the product of the initial mass of the metallic uranium of the fuel assembly and the sum of the masses of the plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 is calculated to obtain the mass of the plutonium in the spent fuel assembly.

[0028] The application also provides a readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the spent fuel assembly nuclear material accounting method.

[0029] The application also provides a spent fuel assembly nuclear material accounting system, which comprises a processor and a memory storing a computer program, and the processor implements the steps of the spent fuel assembly nuclear material accounting method when executing the computer program.

[0030] The application also provides a spent fuel assembly nuclear material accounting system, which comprises:

[0031] The obtaining module is configured to obtain an initial nominal enrichment of a fuel assembly, a type of a spent fuel assembly, a burnup value of the spent fuel assembly, an irradiation duration, and a decay duration.

[0032] The model calculation module is configured to input the initial nominal enrichment, the type, the burnup value, the irradiation duration, and the decay duration into a pre-established fuel assembly decay heat model, and obtain a nuclear material mass table output by the fuel assembly decay heat model, the nuclear material mass table comprising masses of nuclear species produced by nuclear reactions of unit mass of metallic uranium.

[0033] The querying module is configured to receive a specific nuclear species input by a user, and query a mass of the specific nuclear species produced by nuclear reactions of unit mass of metallic uranium from the nuclear material mass table, wherein the specific nuclear species comprises uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242.

[0034] The mass calculation module is configured to obtain an initial mass of metallic uranium of the fuel assembly, and calculate a mass of uranium-235, a mass of plutonium-239, a mass of uranium, and a mass of plutonium in the spent fuel assembly according to the initial mass of the metallic uranium of the fuel assembly and the mass of the specific nuclear species produced by nuclear reactions of unit mass of the metallic uranium.

[0035] Preferably, the fuel assembly decay heat model comprises a concentration calculation model of each nuclide, and the concentration calculation model comprises the following superimposed: a fission generation term of the corresponding nuclide; a neutron capture generation term of the corresponding nuclide; a radioactive decay generation term of the corresponding nuclide; a fission disappearance term of the corresponding nuclide; a neutron capture disappearance term of the corresponding nuclide; and a radioactive decay term of the corresponding nuclide

[0036] The technical solution provided by the present application has the following beneficial effects:

[0037] 1. The fuel assembly decay heat model is used to simulate the irradiation process of a specific fuel assembly in a reactor core and the decay process after shutdown, and in combination with the initial mass of the metal uranium of the fuel assembly, the nuclear material quantity of the spent fuel assembly at a required time point (decay duration) can be calculated;

[0038] 2. For the consumption of short-lived nuclear materials, there is no need for manual decay formula calculation, thus manpower is saved and the risk of human error is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present application, the drawings needed in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0040] Figure 1 is a flow chart of the spent fuel assembly nuclear material calculation method embodiment one of the present application;

[0041] Figure 2A is a relative deviation distribution diagram of the uranium-235 mass of the spent fuel assembly calculated by the present application method and the prior art method, respectively;

[0042] Figure 2B is a relative deviation distribution diagram of the metal uranium mass of the spent fuel assembly calculated by the present application method and the prior art method, respectively;

[0043] Figure 2C is a relative deviation distribution diagram of the plutonium-239 mass of the spent fuel assembly calculated by the present application method and the prior art method, respectively;

[0044] Figure 2D is a relative deviation distribution diagram of the metal plutonium mass of the spent fuel assembly calculated by the present application method and the prior art method, respectively;

[0045] Figure 3 is a logic structure diagram of the spent fuel assembly nuclear material calculation system embodiment one of the present application. DETAILED DESCRIPTION

[0046] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0047] Figure 1 is a flow chart of the nuclear material accounting method for the spent fuel assembly according to an embodiment of the present application, the nuclear material accounting method according to the embodiment includes the following steps:

[0048] Step S10. Obtain the initial nominal enrichment of the fuel assembly, the type of the spent fuel assembly, the burnup value of the spent fuel assembly, the irradiation duration, and the decay duration.

[0049] In this step, it should be noted that the fuel assembly becomes a spent fuel assembly after being burned in the reactor, and for a certain fuel assembly, the initial nominal enrichment is determined by the manufacturing parameters of the fuel assembly, and the type of the spent fuel assembly is also determined. The burnup value and the irradiation duration (running equivalent full power days) of the spent fuel assembly are respectively related to the power of the reactor core operation, and the decay duration is related to the user demand and is set by the user. It can be any time in the cooling period (usually 8 years) between the moment of just stopping the reactor and the moment of transporting the spent fuel assembly for disposal, for example, including: 0 years (the moment of just stopping the reactor), 1 year, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, etc.

[0050] Step S20. Input the initial nominal enrichment, the type, the burnup value, the irradiation duration, and the decay duration into a pre-established fuel assembly decay heat model, and obtain the nuclear material mass table output by the fuel assembly decay heat model, the nuclear material mass table including the mass of each nuclide generated by nuclear reactions per unit mass of metal uranium.

[0051] In this step, the fuel assembly decay heat model is pre-established, which is based on a nuclear database, calls specific component libraries, neutron and gamma energy spectra, divides specific burnup steps, simulates the irradiation process of the fuel assembly in the reactor core and the decay process after stopping the reactor, and determines the concentration of radioactive nuclides of the fuel assembly changing with time by the Bateman differential equation.

[0052] Specifically, the fuel assembly decay heat model comprises a concentration calculation model of each nuclide, which comprises the following superimposed items: a fission generation item of the corresponding nuclide; a neutron capture generation item of the corresponding nuclide; a radioactive decay generation item of the corresponding nuclide; a fission disappearance item of the corresponding nuclide; a neutron capture disappearance item of the corresponding nuclide; and a radioactive decay item of the corresponding nuclide. For example, for a certain nuclide i, the corresponding concentration calculation model comprises the following six parts: 1. a fission generation item, i.e., the generation rate of Ni is determined by the fission rate of nuclide Nj (j is the isotope that generates i); 2. a neutron capture generation item, i.e., the generation rate of Ni is determined by neutron capture {(n, γ), (n, α), (n, p), (n, 2n), (n, 3n)}; 3. a radioactive decay generation item, i.e., the generation rate of Ni is determined by the radioactive decay of Nk (k is the isotope that generates i by radioactive decay); 4. a fission disappearance item, i.e., the disappearance rate of Ni is determined by fission; 5. a neutron capture disappearance item, i.e., the disappearance rate of Ni is determined by neutron capture {(n, γ), (n, α), (n, p), (n, 2n), (n, 3n)}; and 6. a radioactive decay item, i.e., the radioactive decay rate of Ni.

[0053] Step S30. Receiving a specific nuclide input by a user, and querying the mass of the specific nuclide generated by nuclear reaction of unit mass of metallic uranium from the nuclear material mass table, wherein the specific nuclide includes: uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241, plutonium-242;

[0054] In this step, it needs to be explained that since the nuclear material mass table contains the mass of all nuclides (about several hundred) generated by nuclear reaction of unit mass of metallic uranium, and only part of the nuclear materials need to be calculated for nuclear material accounting, therefore, the mass of the specific nuclide needs to be screened from the nuclear material mass table.

[0055] Step S40. Obtaining the initial mass of metallic uranium of the fuel assembly, and calculating the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly according to the initial mass of metallic uranium of the fuel assembly and the mass of the specific nuclide generated by nuclear reaction of unit mass of metallic uranium.

[0056] Through the technical scheme of this embodiment, the mass of nuclear material at any time point from the moment of just stopping the reactor to the moment of transporting the spent fuel assembly for disposal can be calculated, and compared with the existing calculation method, human error can be reduced.

[0057] Further, in step S10, the burnup value and irradiation duration of the spent fuel assembly are obtained in the following manner:

[0058] acquiring power monitoring information of the fuel assembly during operation of the reactor core, wherein the power monitoring information comprises the in-core and out-core nuclear power;

[0059] According to the power monitoring information, the burnup value and irradiation duration of the spent fuel assembly are acquired.

[0060] Further, in step S30, the mass of the specific nuclide produced by the nuclear reaction of the unit mass of metallic uranium can be queried from the nuclear material mass table by using VBA. In step S40, the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly can be calculated by using VBA. By querying and calculating by using VBA, the scheme is simple, and the error of manpower and data processing is reduced.

[0061] Further, in step S40, according to the initial mass of metallic uranium of the fuel assembly and the mass of the specific nuclide produced by the nuclear reaction of the unit mass of metallic uranium, the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly are calculated, comprising:

[0062] Step S41. The product of the initial mass of metallic uranium of the fuel assembly and the mass of uranium-235 produced by the nuclear reaction of the unit mass of metallic uranium queried is calculated to obtain the mass of uranium-235 in the spent fuel assembly;

[0063] Step S42. The product of the initial mass of metallic uranium of the fuel assembly and the mass of plutonium-239 produced by the nuclear reaction of the unit mass of metallic uranium queried is calculated to obtain the mass of plutonium-239 in the spent fuel assembly;

[0064] Step S43. The sum of the mass of uranium-234, uranium-235, uranium-236, and uranium-238 produced by the nuclear reaction of the unit mass of metallic uranium queried is calculated, and the product of the initial mass of metallic uranium of the fuel assembly and the sum of the mass of uranium-234, uranium-235, uranium-236, and uranium-238 is calculated to obtain the mass of uranium in the spent fuel assembly;

[0065] Step S44. The sum of the mass of plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 produced by the nuclear reaction of the unit mass of metallic uranium queried is calculated, and the product of the initial mass of metallic uranium of the fuel assembly and the sum of the mass of plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 is calculated to obtain the mass of plutonium in the spent fuel assembly.

[0066] Of course, in other embodiments, the M X组件the mass of U-234, U-235, U-236, U-238, and the mass of U-234, U-235, U-236, U-238 is the total mass of the metal uranium. Similarly, the mass of M in each group of spent fuel assemblies can be obtained by calculation X组件 the mass of PU-238, PU-239, PU-240, PU-241, PU-242, and the mass of PU-238, PU-239, PU-240, PU-241, PU-242 is the total mass of the metal plutonium.

[0067] Further, after step S40, the method further comprises:

[0068] Step S50. Generating and outputting a nuclear material balance report of the spent fuel assembly according to the calculation result of step S40, wherein the format of the nuclear material balance report is shown in the following table:

[0069]

[0070] The balance results obtained by using the method of the present application and the existing method will be compared below, and the comparison results are as follows:

[0071] 1. The mass of uranium-235

[0072] The main regulated nuclear material in the spent fuel assembly, uranium (U)-235, is a long-lived nuclide, and its mass hardly changes over time during storage in the spent fuel pool. By selecting spent fuel assemblies of different types and different assembly power histories, the mass of uranium-235 in the spent fuel assembly is calculated using the method of the present application and the existing method, respectively, and the results of the two calculation methods are compared. The relative deviation of the two is approximately normally distributed, and the average deviation is about 4%, as shown in Figure 2A .

[0073] 2. The mass of metal uranium

[0074] The spent fuel assembly mainly contains U-234, U-235, U-236, U-238, and other long half-life metal uranium nuclides. During storage in the spent fuel pool (generally after 8 years of storage in the spent fuel pool, the spent fuel is shipped out), the mass of the nuclides hardly changes. By selecting spent fuel assemblies of different types and different assembly power histories, the mass of metal uranium in the spent fuel assembly is calculated using the method of the present application and the existing method, respectively, and the results of the two calculation methods are compared. The relative deviation of the two is not large, most of the relative deviations are concentrated around 0, and a small part of the relative deviations are about 1% to 2%, as shown in Figure 2B .

[0075] 3. The mass of plutonium-239

[0076] The main regulated nuclear material in the spent fuel assembly, Pu-239, is a long-lived nuclide, and its mass hardly changes with time during storage in the spent fuel pool. By selecting spent fuel assemblies of different types and different assembly power histories, the mass of Pu-239 in the spent fuel assembly is calculated by using the method of the present application and the existing method respectively, and the results of the two calculation methods are compared. The relative deviation of the two is approximately normally distributed, and the average deviation is about 1%, and the relative deviation is shown in Table 1. Figure 2C .

[0077] 4. Mass of metallic plutonium

[0078] The spent fuel assembly mainly contains Pu-238, Pu-239, Pu-240, Pu-241, Pu-242 and other metallic plutonium nuclides. Among them, Pu-241 is a short-lived nuclide with a half-life of 14.35 years, and its mass decreases during storage in the spent fuel pool. By selecting spent fuel assemblies of different types and different assembly power histories, the mass of metallic plutonium in the spent fuel assembly is calculated by using the method of the present application and the existing method respectively. It should be noted that after the mass of Pu-241 in the spent fuel assembly just after unloading is obtained by using the existing method, the mass of Pu-241 is calculated according to the decay formula:

[0079]

[0080] Finally, the results of the two calculation methods are compared, and according to the comparison results, there is a slight difference in the change with time. Taking the case of cooling in the spent fuel pool for eight years as an example, the relative deviation of the two is approximately normally distributed, and the average deviation is about 0.3%, and the relative deviation is shown in Table 2. Figure 2D .

[0081] From the above comparative analysis, it can be seen that compared with the existing method, the mass of metallic uranium, metallic plutonium, uranium-235 and plutonium-239 in the spent fuel assembly calculated by the method of the present application has smaller deviation. The relative deviation of the mass of metallic uranium is mostly about 0%, and a small part is about 1% to 2%. The relative deviation of the mass of metallic plutonium, uranium-235 and plutonium-239 is small and normally distributed around 0. Therefore, the method of the present application can replace the existing method for nuclear material accounting, and does not need to be calculated artificially by using the decay formula, thereby reducing the labor cost and the risk of human error.

[0082] The present application also provides a readable storage medium storing a computer program, and the computer program implements the steps of the nuclear material accounting method of the spent fuel assembly when executed by a processor.

[0083] The application also discloses a nuclear material accounting system of the spent fuel assembly, which comprises a processor and a memory storing a computer program.

[0084] Figure 3 FIG. 1 is a logic structure diagram of an embodiment of the nuclear material accounting system of the spent fuel assembly according to the application, which comprises an acquisition module 10, a model calculation module 20, an inquiry module 30 and a mass calculation module 40. The acquisition module 10 is used to acquire the initial nominal enrichment of the fuel assembly, the type of the spent fuel assembly, the burnup value of the spent fuel assembly, the irradiation duration and the decay duration. The model calculation module 20 is used to input the initial nominal enrichment, the type, the burnup value, the irradiation duration and the decay duration into a pre-established fuel assembly decay heat model, and acquire a nuclear material mass table output by the fuel assembly decay heat model, wherein the nuclear material mass table comprises the mass of each nuclide generated by the nuclear reaction of unit mass of metallic uranium. The inquiry module 30 is used to receive a specific nuclide input by a user, and inquire the mass of the specific nuclide generated by the nuclear reaction of unit mass of metallic uranium from the nuclear material mass table, wherein the specific nuclide comprises uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241 and plutonium-242. The mass calculation module 40 is used to acquire the initial mass of the metallic uranium of the fuel assembly, and calculate the mass of uranium-235, the mass of plutonium-239, the mass of uranium and the mass of plutonium in the spent fuel assembly according to the initial mass of the metallic uranium of the fuel assembly and the mass of the specific nuclide generated by the nuclear reaction of unit mass of metallic uranium.

[0085] Further, the fuel assembly decay heat model comprises a concentration calculation model of each nuclide, and the concentration calculation model comprises the following items superimposed on each other: a fission generation item of the corresponding nuclide; a neutron capture generation item of the corresponding nuclide; a radioactive decay generation item of the corresponding nuclide; a fission disappearance item of the corresponding nuclide; a neutron capture disappearance item of the corresponding nuclide; and a radioactive decay item of the corresponding nuclide.

[0086] The above merely provides the preferred embodiments of the application, but should not be used to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modified, equivalent replaced, improved and the like within the spirit and principle of the application should be included in the scope of claims of the application.

Claims

1. A method of nuclear material accounting for a spent fuel assembly, characterized by, The method comprises the following steps: Step S10. Obtain the initial nominal enrichment of the fuel assembly, the type of the spent fuel assembly, the burnup value of the spent fuel assembly, the irradiation time length, and the decay time length; Step S20. Input the initial nominal enrichment, the type, the burnup value, the irradiation time length, and the decay time length into a pre-established fuel assembly decay heat model, and obtain a nuclear material mass table output by the fuel assembly decay heat model, wherein the fuel assembly decay heat model comprises a concentration calculation model of each nuclide, and the concentration calculation model comprises the following items superimposed on each other: a fission generation item of a corresponding nuclide; a neutron capture generation item of the corresponding nuclide; a radioactive decay generation item of the corresponding nuclide; a fission disappearance item of the corresponding nuclide; a neutron capture disappearance item of the corresponding nuclide; and a radioactive decay item of the corresponding nuclide, and the nuclear material mass table comprises the mass of each nuclide generated by nuclear reaction of unit mass of metallic uranium; Step S30. Receive a specific nuclide input by a user, and query the mass of the specific nuclide generated by nuclear reaction of unit mass of metallic uranium from the nuclear material mass table, wherein the specific nuclide comprises: uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242; Step S40. Obtain the initial mass of metallic uranium of the fuel assembly, and calculate the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly according to the initial mass of the metallic uranium and the mass of the specific nuclide generated by nuclear reaction of unit mass of the metallic uranium. In the step S40, the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly are calculated according to the initial mass of the metallic uranium of the fuel assembly and the mass of the specific nuclide generated by nuclear reaction of unit mass of the metallic uranium, comprising: calculating the product of the initial mass of the metallic uranium of the fuel assembly and the mass of uranium-235 generated by nuclear reaction of unit mass of the metallic uranium that is queried, to obtain the mass of uranium-235 in the spent fuel assembly; calculating the product of the initial mass of the metallic uranium of the fuel assembly and the mass of plutonium-239 generated by nuclear reaction of unit mass of the metallic uranium that is queried, to obtain the mass of plutonium-239 in the spent fuel assembly; calculating the sum of the mass of uranium-234, uranium-235, uranium-236, and uranium-238 generated by nuclear reaction of unit mass of the metallic uranium that is queried, and calculating the product of the initial mass of the metallic uranium of the fuel assembly and the sum of the mass of uranium-234, uranium-235, uranium-236, and uranium-238, to obtain the mass of uranium in the spent fuel assembly; calculating the sum of the mass of plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 generated by nuclear reaction of unit mass of the metallic uranium that is queried, and calculating the product of the initial mass of the metallic uranium of the fuel assembly and the sum of the mass of plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242, to obtain the mass of plutonium in the spent fuel assembly.

2. The method of claim 1, wherein In the step S10, the burnup value and irradiation duration of the spent fuel assembly are obtained according to the following manner: obtaining power monitoring information of the fuel assembly during the operation in the core; obtaining the burnup value and irradiation duration of the spent fuel assembly according to the power monitoring information.

3. The method of claim 1, wherein the nuclear material accounting of the spent fuel assembly is performed by a method comprising: After the step S40, further comprising: Step S50. generating and outputting a nuclear material accounting report of the spent fuel assembly according to the calculation result of the step S40.

4. The method of claim 1, wherein the nuclear material accounting of the spent fuel assembly is performed by a method comprising: In the step S30, the mass of the specific nuclide generated by the nuclear reaction of unit mass of metallic uranium is queried from the nuclear material mass table, comprising: querying the mass of the specific nuclide generated by the nuclear reaction of unit mass of metallic uranium from the nuclear material mass table by using VBA; and / or, In the step S40, the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly are calculated, comprising: calculating the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly by using VBA.

5. A readable storage medium, storing a computer program, characterized in that, The computer program, when executed by a processor, implements the steps of the nuclear material accounting method of the spent fuel assembly according to any one of claims 1-4.

6. A nuclear material accounting system for spent fuel assemblies, comprising a processor and a memory having stored therein a computer program, wherein, The processor, when executing the computer program, implements the steps of the nuclear material accounting method of the spent fuel assembly according to any one of claims 1-4.

7. A nuclear material accounting system for spent fuel assemblies, characterized by, comprising: an obtaining module, configured to obtain an initial nominal enrichment of a fuel assembly, a type of a spent fuel assembly, a burnup value of the spent fuel assembly, an irradiation duration, and a decay duration; a model calculation module, configured to input the initial nominal enrichment, the type, the burnup value, the irradiation duration, and the decay duration into a pre-established fuel assembly decay heat model, and obtain a nuclear material mass table output by the fuel assembly decay heat model, the fuel assembly decay heat model comprising a concentration calculation model of each nuclide, and the concentration calculation model comprising the following items superimposed on each other: a fission generation item of a corresponding nuclide; a neutron capture generation item of the corresponding nuclide; a radioactive decay generation item of the corresponding nuclide; a fission disappearance item of the corresponding nuclide; a neutron capture disappearance item of the corresponding nuclide; and a radioactive decay item of the corresponding nuclide, the nuclear material mass table comprising the mass of each nuclide generated by the nuclear reaction of unit mass of metallic uranium; a querying module, configured to receive a specific nuclide input by a user, and query the mass of the specific nuclide generated by the nuclear reaction of unit mass of metallic uranium from the nuclear material mass table, wherein the specific nuclide comprises: uranium-234, uranium-235, uranium-236, uranium-238, plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242; a mass calculation module, configured to obtain an initial mass of metallic uranium of the fuel assembly, and calculate the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly according to the initial mass of metallic uranium of the fuel assembly and the mass of the specific nuclide generated by the nuclear reaction of unit mass of metallic uranium. The mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly are calculated according to the initial mass of the metallic uranium of the fuel assembly and the mass of the specific nuclide generated by the nuclear reaction of the unit mass of the metallic uranium, and the mass of uranium-235, the mass of plutonium-239, the mass of uranium, and the mass of plutonium in the spent fuel assembly are calculated, including: calculating the product of the initial mass of the metallic uranium of the fuel assembly and the mass of uranium-235 generated by the nuclear reaction of the unit mass of the metallic uranium to obtain the mass of uranium-235 in the spent fuel assembly; calculating the product of the initial mass of the metallic uranium of the fuel assembly and the mass of plutonium-239 generated by the nuclear reaction of the unit mass of the metallic uranium to obtain the mass of plutonium-239 in the spent fuel assembly; calculating the sum of the masses of uranium-234, uranium-235, uranium-236, and uranium-238 generated by the nuclear reaction of the unit mass of the metallic uranium, and calculating the product of the initial mass of the metallic uranium of the fuel assembly and the sum of the masses of uranium-234, uranium-235, uranium-236, and uranium-238 to obtain the mass of uranium in the spent fuel assembly; calculating the sum of the masses of plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 generated by the nuclear reaction of the unit mass of the metallic uranium, and calculating the product of the initial mass of the metallic uranium of the fuel assembly and the sum of the masses of plutonium-238, plutonium-239, plutonium-240, plutonium-241, and plutonium-242 to obtain the mass of plutonium in the spent fuel assembly.

Images