JP5667802B2 - Storage support method for spent fuel assembly, storage support device for spent fuel assembly, and storage method for spent fuel assembly in cask - Google Patents

Description

  The present invention relates to a storage support method for spent fuel assemblies, a storage support device for spent fuel assemblies, and a storage method for spent fuel assemblies in a cask, and in particular, a boiling water nuclear power plant and a pressurized water nuclear power plant. Spent fuel assembly storage support method, spent fuel assembly storage support device, and spent fuel assembly storage method in cask suitable for storing spent fuel assembly generated from power plant in cask About.

  Spent fuel assemblies originating from nuclear plants are reprocessed to recover reusable nuclear fuel materials such as uranium and plutonium. Generally, spent fuel assemblies are stored while being cooled in a fuel storage pool provided in a nuclear power plant for a relatively long period of time before being transported to a reprocessing facility. On the other hand, spent fuel assemblies are generated every year in nuclear power plants, and there is a concern that the capacity of the fuel storage pool in the nuclear power plant that stores these spent fuel assemblies will become insufficient. .

  For this reason, these spent fuel assemblies stored in the fuel storage pool are stored in the cask, and the cask containing the spent fuel assemblies (for example, metal cask) is re-used by equipment other than the fuel storage pool. It is planned to keep it until it is processed. In the cask used for transportation of spent fuel assemblies, a condition with a large margin is set in safety analysis for confirming safety in consideration of transportation that is repeatedly used. On the other hand, since the target spent fuel assembly is stored only once in principle in the storage cask, when the specifications of the transport cask are applied to the storage cask, The fuel specification may have an excessive margin.

  When selecting spent fuel assemblies to be stored in the cask, thousands to tens of thousands of spent fuel assemblies having different types, burnups, and cooling periods after removal from the reactor are targeted. In the cask that stores these spent fuel assemblies, the total amount of radioactivity and calorific value is set. Therefore, it can be stored in the cask according to the radioactivity and heat value of each spent fuel assembly calculated based on the burnup and cooling period of each spent fuel assembly for each type of spent fuel assembly. The number of spent fuel assemblies is determined. It takes enormous effort and time to calculate the radioactivity and the calorific value for each of the enormous number of spent fuel assemblies to be processed using a calculation code.

  Therefore, the following storage plans for spent fuel assemblies are being carried out. First, all spent fuel assemblies to be stored are classified by type, and the spent fuel assemblies are grouped for each classified type based on the burnup of the spent fuel assemblies assumed in the cask design. Since the cooling period of the corresponding spent fuel assembly can be set based on the cask delivery plan, the cooling period of the spent fuel assembly at the time of removal from the fuel storage pool is set, and the burnup and cooling period data Based on the above, the storage plan for the spent fuel assembly in the cask is planned.

  An example of a method for storing a spent fuel assembly in a cask is described in Japanese Patent Application Laid-Open No. 2008-232718. In this spent fuel assembly storage method, the source strength of each selected spent fuel assembly is calculated using the burnup of the plurality of spent fuel assemblies selected for storage in the cask. Then, each storage position of the selected spent fuel assembly in the cask is set based on the calculated source strength of each spent fuel assembly, and each spent fuel is set in each housing position. Select when the dose rate around the cask is calculated using the source intensity of each spent fuel assembly and the calculated dose rate is less than the first set dose rate in the state where the assemblies are arranged Each spent fuel assembly is stored in a cask.

  According to this method for storing spent fuel assemblies, it is possible to reduce the time required from the start of selecting spent fuel assemblies to be stored in the cask to the carrying out of the cask containing the predetermined number of spent fuel assemblies. Can do.

JP 2008-232718 A

  When a plurality of nuclear power plants are installed in one nuclear power plant, the total number of spent fuel assemblies stored in the fuel storage pool of each nuclear power plant becomes several thousand to several tens of thousands. When selecting spent fuel assemblies to be stored in the cask, the larger the number of spent fuel assemblies to be stored, the more used fuel assemblies to be stored that satisfy the specifications of the cask. Easy to select. However, the spent fuel assemblies stored in a predetermined number of casks from a large number of spent fuel assemblies stored in a plurality of fuel storage pools in one nuclear power plant satisfy the specifications of the cask. It is not easy to select as such.

  The cask must contain the spent fuel assembly so as to satisfy the radioactivity set value and the calorific value set value which are the specifications of the cask. It is desirable to satisfy these set values and store the spent fuel assemblies in the cask so that the number of stored assemblies is the specification of the cask, thereby increasing the storage efficiency of the spent fuel assemblies. A spent fuel assembly having a relatively high burnup and a spent fuel assembly having a short stay period (cooling period) in the fuel storage pool are also stored in the fuel storage pool. It is necessary to store spent fuel assemblies having a relatively high burnup and spent fuel assemblies having a short cooling period in the cask so as not to remain as much as possible. However, in order to select a spent fuel assembly to be stored in a cask, including a spent fuel assembly having a relatively high burnup and a spent fuel assembly having a short cooling period, for a predetermined number of casks, Requires a long time.

  In the method of storing spent fuel assemblies in a cask described in Japanese Patent Laid-Open No. 2008-232718, the source strength of the spent fuel assemblies is mainly calculated based on the burnup of the spent fuel assemblies. The dose rate around the cask containing the required number of spent fuel assemblies is calculated using the calculated source intensity. However, this storage method does not directly consider the amount of heat generated.

  We are considering storing the spent fuel assembly in the cask so as to satisfy the set values of radioactivity and calorific value. That is, a plurality of fuel assemblies to be stored are classified into a plurality of groups, and the radioactivity and calorific value obtained under the strictest conditions in each classified group are treated as representative values of each group, and the cask We are considering determining the number of spent fuel assemblies required for each unit. At this time, each fuel condition of each group is set so as to envelop all the radioactivity and decay heat of each spent fuel assembly included in the corresponding group. It is a safe setting for the body. For this reason, there may be cases where the safety margin of the cask is set larger for each spent fuel assembly, and the storage plan for the spent fuel assembly in the cask results in a considerable margin. ing. In the intermediate fuel storage by a cask (for example, a metal cask), high storage efficiency of the spent fuel assembly is required, and setting a larger safety margin of the cask can be performed in the cask of the spent fuel assembly. As a result, the storage efficiency of the spent fuel assembly in the intermediate storage facility is reduced.

  To solve this problem, calculate the radioactivity and calorific value of several thousand to tens of thousands of spent fuel assemblies, one by one, using the calculation code, and use the spent fuel assemblies to the cask. You should consider the storage plan in detail. However, when planning the most efficient storage plan for several casks for several thousand to tens of thousands of spent fuel assemblies, the cooling period of the spent fuel assemblies is used as a parameter. Therefore, tremendous sensitivity analysis of tens of thousands of cases needs to be performed with calculation codes, and it takes a lot of time and effort to make a storage plan.

  The object of the present invention is to support the storage of spent fuel assemblies that can further reduce the time required for storage planning of spent fuel assemblies in a plurality of casks and improve the efficiency of storing spent fuel assemblies in the cask. It is an object to provide a method, a storage support device for spent fuel assemblies, and a method for storing spent fuel assemblies in a cask.

The feature of the present invention that achieves the above-described object is that, for each of a plurality of spent fuel assemblies to be stored, which are stored in a plurality of designated casks, a radioactivity and a calorific value are respectively calculated by a processing unit. A first step of calculating based on the burnup and cooling period of the spent fuel assembly of
A second step of selecting a plurality of spent fuel assemblies to be stored in the cask from a plurality of spent fuel assemblies to be stored by an arithmetic processing unit;
The radioactivity of the cask when a plurality of selected spent fuel assemblies are stored is calculated using the radioactivity calculated for each of the selected spent fuel assemblies by the arithmetic processing unit. The third step,
The calorific value of the cask when the plurality of selected spent fuel assemblies are stored is calculated by the arithmetic processing unit using the calorific value calculated for each of the selected spent fuel assemblies. Fourth step, and when the plurality of selected spent fuel assemblies are stowed when the radioactivity of the cask when the plurality of selected spent fuel assemblies are stowed is less than the set value of the cask radioactivity The number of casks that contain the selected multiple spent fuel assemblies satisfying the number specified by the arithmetic processing unit. A fifth step of determining whether or not
In the fifth step, when it is determined that the number of cask bases below the cask radioactivity setting value and the cask calorific value setting value satisfies a plurality of designated units, the used items are stored for each cask. The decision is to determine the fuel assembly.

  The calorific value of the cask when a plurality of selected spent fuel assemblies are stowed when the radioactivity of the cask when the plurality of selected spent fuel assemblies are stowed is less than the radioactivity setting value of the cask It is determined whether or not the number of casks in which a plurality of selected spent fuel assemblies are stored satisfying a plurality of designated units that is less than the calorific value set value of the cask. The time required for storage planning for determining a plurality of spent fuel assemblies to be accommodated in each radix cask can be further shortened, and the efficiency of storing spent fuel assemblies in the cask can be improved. it can.

  According to the present invention, it is possible to further reduce the time required for storing spent fuel assemblies in a plurality of casks, and to improve the efficiency of storing spent fuel assemblies in a cask.

It is a block diagram of the accommodation assistance apparatus of the spent fuel assembly which is one suitable Example of this invention. It is a flowchart which shows the process sequence performed with the data processor shown in FIG. FIG. 2 is an explanatory diagram illustrating an example of information such as a burnup degree and a cooling period of each spent fuel assembly to be stored, which is stored in a memory illustrated in FIG. 1. It is explanatory drawing which shows an example of the accommodation pattern (two area | region pattern) which arrange | positions several spent fuel assemblies in a cask. It is explanatory drawing which shows an example of the other storage pattern (three area | region pattern) which arrange | positions several spent fuel assemblies in a cask. It is explanatory drawing which shows an example of the other storage pattern (four area | region pattern) which arrange | positions several spent fuel assemblies in a cask. It is explanatory drawing which showed the data processor of FIG. 1 which performs the process sequence shown in FIG. 2 with the functionally equivalent hardware structure. It is the characteristic view which arranged the change with respect to the cooling period of the emitted-heat amount of a spent fuel assembly for every burnup. It is the characteristic view which arranged the change with respect to the cooling period of the radioactivity of a spent fuel assembly for every burnup. It is a characteristic view which shows the relationship between the radioactivity and cooling period in an 8x8BJ type spent fuel assembly for every burnup. It is a characteristic view which shows the relationship between the emitted-heat amount and cooling period in an 8x8BJ type spent fuel assembly for every burnup. It is a block diagram of the fuel assembly storage device which is another embodiment of the present invention.

  The inventors pay attention to the burnup and cooling period of the spent fuel assembly stored in the fuel storage pool, and the relationship between the burnup, the cooling period and the calorific value of the fuel assembly, and the burnup and cooling period. And the relationship between the radioactivity of the fuel assembly was examined. The burnup of the spent fuel assembly is the burnup at the time when the spent fuel assembly is taken out from the core of the nuclear reactor that has been shut down. The cooling period of the fuel assembly is an elapsed period from the time when the fuel assembly is taken out from the core and carried into the fuel storage pool and stored, and the spent fuel assembly is stored in the fuel storage pool. . The calorific value and the radioactivity of the fuel assembly are the respective values at the time of removal from the fuel storage pool for storage in the cask.

  FIG. 8 shows the relationship between the calorific value, burnup, and cooling period of the spent fuel assembly. Further, FIG. 9 shows the relationship among the radioactivity, burnup and cooling period of the spent fuel assembly. According to FIGS. 8 and 9, the radioactivity and the calorific value of the spent fuel assembly tend to increase as the burnup of the spent fuel assembly increases. The longer the cooling period of the spent fuel assembly, the lower the radioactivity and heat value of the spent fuel assembly.

  When enormous numbers of spent fuel assemblies are to be stored in a specified number of casks, the spent fuel assemblies classified into several groups have the maximum combustion condition (burning rate) in each group. Have. As shown in FIGS. 8 and 9, the calorific value and the radioactivity increase and decrease depending on the burnup. When the burnup increases by about 2000 MWd / t, the calorific value and radioactivity increase by about 7%. For this reason, even in the same group, for example, there are spent fuel assemblies having different burnups such as the maximum, that is, the representative value, the minimum value, and the intermediate value between the representative value and the minimum value. In the aggregate, the difference in radioactivity and calorific value tends to increase.

  Regarding the spent fuel assembly stored in the cask, the burnup and the cooling period after being stored in the fuel storage pool are managed as known data. For this reason, if the inventors can accurately determine the radioactivity and the calorific value of the spent fuel assembly based on the burnup and cooling period that are being controlled, the inventors can target individual spent fuel assemblies. In addition, it is no longer necessary to perform a sensitivity analysis using a calculation code, greatly reducing the time required to calculate the radioactivity and calorific value of each spent fuel assembly, and more efficient use in the cask. We thought that the storage plan for spent fuel assemblies could be achieved in a short time.

  Therefore, the inventors examined how to determine the radioactivity and the calorific value of various spent fuel assemblies based on the burnup and the cooling period. The spent fuel assemblies to be studied are 8 × 8 BJ type spent fuel assemblies used in boiling water reactors (BWR), STEP II type spent fuel assemblies and STEP III type spent fuel assemblies. Is the body. As a result of this examination, the inventors calculated the burnup and cooling period of the spent fuel assembly and the spent period of the spent fuel assembly by the equation (1). It has been found that the relationship of the calorific value of the fuel assembly can be expressed by equation (2).

A = α1 · BU · e ^{−β1 · CT} (1)
H = α2 · BU · e ^{−β2 · CT} (2)
Here, A is the radioactivity of the spent fuel assembly, H is the calorific value of the spent fuel assembly, BU is the burnup (MWd / t) of the spent fuel assembly, and CT is stored in the fuel storage pool. Thereafter, the cooling period (year) of the spent fuel assembly, and α1, α2, β1, and β2 are constants.

  The relationship between the burn-up and cooling period of the spent fuel assembly newly found by the inventors and the radioactivity (or calorific value) of the spent fuel assembly will be described in detail for the spent fuel assemblies of different types. .

First, an 8 × 8 BJ type spent fuel assembly will be described. FIG. 10 shows the change in radioactivity of the spent fuel assembly according to the cooling period of the spent fuel assembly, with the burnup as a parameter in the 8 × 8 BJ type spent fuel assembly. In FIG. 10, the relationship between the radioactivity A of the spent fuel assembly and the cooling period CT of the spent fuel assembly is represented by an equation for each burnup of the 8 × 8 BJ type spent fuel assembly. For example, at a burnup of 30000 MWd / t, the relationship between the radioactivity A of the spent fuel assembly and the cooling period CT of the spent fuel assembly is
A = 78345e ^-0.0283CT
It is represented by Here, since “78345” is “α1 · BU” in the equation (1), 78345 = 30000α1. When the constant α1 is obtained from this relationship, the constant α1 is 2.61.

  Each relational expression of the radioactivity A (Ci / body) of the 8 × 8 BJ type spent fuel assembly shown in FIG. 10 and the cooling period CT (year) of the spent fuel assembly of this type is the spent fuel When the burnup BU (MWd / t) of the aggregate is arranged as a parameter, it is expressed as the following equation (3).

A = 2.59 · BU · e ^−0.0283CT (3)
Here, α1 = 2.59 is a value of the constant α1 obtained in the relational expression between the radioactivity A of the spent fuel assembly and the cooling period CT of the spent fuel assembly for each burnup shown in FIG. Is the average. Further, “−0.0283” in the expression (3) is a relational expression between the radioactivity A of the spent fuel assembly and the cooling period CT of the spent fuel assembly for each burnup shown in FIG. It is a value obtained by averaging the constant β1.

FIG. 11 shows the change in the amount of heat generated by the spent fuel assembly depending on the cooling period of the spent fuel assembly, using the burnup as a parameter in the 8 × 8 BJ type spent fuel assembly. In FIG. 11, the relationship between the calorific value H of the spent fuel assembly and the cooling period CT of the spent fuel assembly is represented by an equation for each burnup of the 8 × 8 BJ type spent fuel assembly. For example, at a burnup of 30000 MWd / t, the relationship between the calorific value H of the spent fuel assembly and the cooling period CT of the spent fuel assembly is
H = 196.31e- ^0.0182CT
It is represented by

  Each relational expression of the calorific value H (Watt / body) of the 8 × 8 BJ type spent fuel assembly and the cooling period CT (year) of this type spent fuel assembly shown in FIG. When the burnup BU (MWd / t) of the aggregate is arranged as a parameter, it is expressed as in equation (4).

H = 0.068 · BU · e ^−0.0188CT (4)
The inventors calculated the radioactivity A and the calorific value B of the spent fuel assembly calculated using the formulas (3) and (4) and the cooling period calculated using the calculation code described above. It was confirmed that there was good agreement within 2% between 15 and 30 years.

  The radioactivity and calorific value of the 8 × 8 BJ type spent fuel assemblies taken out from the BWR core and stored in the fuel storage pool are based on the burnup and cooling period of the spent fuel assemblies ( It can obtain | require with sufficient precision using 3) Formula and (4) Formula.

  The radioactivity and calorific value of a spent fuel assembly of a type different from the 8 × 8 BJ type spent fuel assembly, for example, a STEP II type spent fuel assembly and a STEP III type spent fuel assembly, Similar to the 8 × 8 BJ type spent fuel assembly, it can be calculated based on the burnup and cooling period of the corresponding type spent fuel assembly.

  The radioactivity A (Ci / body) of the STEPII type spent fuel assembly is calculated using the burnup BU (MWd / t) and the cooling period CT (year) of this spent fuel assembly as shown in equation (5). It is expressed as follows.

A = 2.68 · BU · e ^-0.0243CT (5)
Further, the calorific value H (Watt / body) of the STEPII type spent fuel assembly is calculated by using the burnup BU (MWd / t) and the cooling period CT (year) of the spent fuel assembly (6) It is expressed as an expression.

H = 0.0077 · BU · e ^−0.0243CT (6)
The deviation between the radioactivity A and calorific value B of the STEPII type spent fuel assembly calculated using the equations (5) and (6) and those obtained using the above calculation code is about 7 %.

  The equation (1) for calculating the radioactivity of the spent fuel assembly based on the burnup and cooling period of the spent fuel assembly described above, and the equation (2) for calculating the calorific value are the BWR spent fuel assembly. It can be applied not only to the body but also to the spent fuel assembly of a pressurized water reactor.

A storage support device for spent fuel assemblies, which is a preferred embodiment of the present invention, will be described with reference to FIG. The spent fuel assembly storage support device 1 of the present embodiment includes a data processing device 2, a display device 6, and an input device 7 such as a keyboard and a mouse. The data processing device 2 is an electronic computer and includes a central processing unit (CPU) 3, a memory 4, and an input / output interface 5.
The CPU 3 and the memory 4 are connected to the input / output interface 5, and the input device 7 and the display device 6 are also connected to the input / output interface 5. A program for executing the processing shown in FIG. 2 is stored in the memory 4. Processing by this program is executed by the CPU 3 of the data processing device 2.

  A spent fuel assembly storage support method using the spent fuel assembly storage support device 1 will be described below. A certain nuclear power plant has a plurality of, for example, two nuclear power plants. A plurality of spent fuel assemblies stored in respective fuel storage pools of two nuclear power plants are stored in a plurality of casks, and a plurality of spent fuel assemblies are stored in an intermediate storage facility outside the nuclear power plant. Assume that multiple casks are stored in the body. In this case, it is necessary to store the spent fuel assemblies stored in the fuel storage pools of the two nuclear power plants in a plurality of casks in the nuclear power plant. The spent fuel assembly storage support apparatus 1 is used to determine a plurality of spent fuel assemblies to be stored for each cask. Here, for example, 5175 8 × 8 BJ type spent fuel assemblies stored in each fuel storage pool are stored in 75 casks.

  A spent fuel assembly storage support method using the spent fuel assembly storage support apparatus 1 will be described based on the processing procedure shown in FIG.

  The operator activates the spent fuel assembly storage support device 1 and inputs a processing start command from the input device 7. When this process start command is input, the CPU 3 reads a program for executing each process shown in FIG. 2 from the memory 4 and sequentially executes these processes. The memory 4 stores arithmetic expressions of radioactivity and calorific value corresponding to the type of spent fuel assembly, such as Expressions (3), (4), (5), and (6).

  Information on the burnup and cooling period of each spent fuel assembly to be stored in the cask is input (step S1). Data on burnup and cooling period of, for example, 5175 8 × 8 BJ type spent fuel assemblies to be stored in a plurality of (for example, 75) casks registered in a CD-ROM The data is read by a reading device (not shown) and stored in the memory 4 via the input / output interface 5. These spent fuel assemblies housed in a plurality of casks are respectively stored in the fuel storage pools of each nuclear power plant described above of the nuclear power plant. The burnup of the spent fuel assembly is the burnup at the time of removal from the core of the nuclear power plant, and the cooling period is a period after the start of storage in the cooling water in the fuel storage pool. In step S1, the identification number (ID) of each spent fuel assembly, the burnup (BU) and the cooling period (CT) of each spent fuel assembly shown in FIG. Is remembered. The identification number is referred to as fuel ID.

  The type and number of spent fuel assemblies to be stored in the cask and the base number of the cask are input (step S2). The operator uses the input device 7 to select the type of spent fuel assemblies to be stored in the cask (for example, 8 × 8 BJ type spent fuel assemblies) and the number of spent fuel assemblies stored per cask. (For example, 69 bodies) and the base number (for example, 75 bodies) of the cask that stores all the used spent fuel assemblies as targets. These data are stored in the memory 4 by the CPU 3.

The radioactivity of the spent fuel assembly is calculated (step S3). The radioactivity A of 5175 spent fuel assemblies is calculated using equation (1), specifically, equation (3) for an 8 × 8 BJ type spent fuel assembly. For example, in the spent fuel assembly having the fuel ID “2”, the radioactivity A ₂ is calculated by substituting BU ₂ for BU and CT ₂ for CT in the equation (3). The obtained radioactivity A ₂ is stored in the memory 4.

The calorific value of the spent fuel assembly is calculated (step S4). Using the equation (2), specifically, the equation (4) for an 8 × 8 BJ type spent fuel assembly, the calorific value H of 5175 spent fuel assemblies (for example, in FIG. 3) The indicated H ₁ , H ₂ ,..., H _N ) are respectively calculated. Each calorific value H calculated is stored in the memory 4.

  The specifications of the target cask (radioactivity set value, calorific value set value, and number of storage units of spent fuel assemblies) are input (step S5). The operator inputs the type of cask to be used from the input device 7. That is, the type of cask to be used is specified. The CPU 3 reads, from the memory 4, the radioactivity setting value, the calorific value setting value, and the number of stored spent fuel assemblies in the cask based on the information on the designated cask type. These data are input into the CPU 3.

  A storage pattern for spent fuel assemblies in the cask is selected (step S6). The operator inputs selection information for the storage pattern of the spent fuel assembly from the input device 7.

The memory 4 stores storage pattern information of spent fuel assemblies shown in FIGS. 4, 5, and 6. The storage pattern shown in FIG. 4 is a pattern for storing spent fuel assemblies in two areas. In the storage pattern (hereinafter referred to as “two-region pattern”), in the cross section of the cask, the region R2 is disposed at the center, and the region R1 is disposed around the region R2 at the periphery. In the region R1, for example, 32 spent fuel assemblies (hereinafter referred to as first fuel assemblies) having a burn-up BU of 30000 MWd / t or less are arranged, and in the region R2,
37 spent fuel assemblies (hereinafter referred to as second fuel assemblies) satisfying 30000 MWd / t <BU ≦ 35000 MWd / t are arranged. The cask can hold 69 spent fuel assemblies.

  The storage pattern shown in FIG. 5 is a pattern for storing spent fuel assemblies in three regions. This storage pattern (hereinafter referred to as “three-region pattern”) includes a region R3 at the center, a region R3 that surrounds the region R3, a region R2 that surrounds the region R2, and a region R1 that surrounds the region R2. It is arranged. In the three-region pattern region R1, 24 first fuel assemblies arranged in the two-region pattern region R1 are arranged, and in the three-region pattern region R2, the second fuel is arranged in the two-region pattern region R2. Thirty-two assemblies are arranged. In the region R3 of the three region pattern, for example, 13 spent fuel assemblies (hereinafter referred to as third fuel assemblies) having a burnup BU satisfying 35000 MWd / t <BU ≦ 38000 MWd / t are arranged. This cask can also accommodate 69 spent fuel assemblies.

  The storage pattern shown in FIG. 6 is a pattern for storing spent fuel assemblies in four regions. This storage pattern (hereinafter, referred to as a four-region pattern) has, in the cross section of the cask, a region R4 at the center, a region R2 that surrounds the region R4, a region R2 that surrounds the region R2, and a region R2 at the periphery. Region R3 is arranged between R4 and region R2. Twenty-four first fuel assemblies arranged in the two-region pattern region R1 are arranged in the four-region pattern region R1, and the second fuel arranged in the two-region pattern region R2 in the four-region pattern region R2. Twenty-four assemblies are arranged. Eight third fuel assemblies arranged in the three-region pattern region R3 are arranged in the four-region pattern region R3. In the four-region pattern region R4, for example, 13 spent fuel assemblies (hereinafter, referred to as fourth fuel assemblies) with a burnup BU satisfying 38000 MWd / t <BU ≦ 41000 MWd / t are arranged. This cask can also accommodate 69 spent fuel assemblies.

  Information on the storage pattern of the spent fuel assembly such as the two-region pattern, the three-region pattern, and the four-region pattern is stored in the memory 4. Information on other storage patterns other than the storage pattern information is also stored in the memory 4.

  After the input of the specification of the target cask is completed in step S <b> 5, the CPU 3 reads information on each storage pattern of the spent fuel assembly from the memory 4 and outputs it to the display device 6. The operator designates, for example, one storage pattern among the storage patterns displayed on the display device 6 using the mouse. The operator also inputs the number of casks (for example, 75) to which the specified storage pattern is applied from the input device 7. The CPU 3 selects a designated storage pattern, for example, a two-region pattern, and inputs each piece of information shown in FIG. Information regarding the two-region pattern is displayed on the display device 6. Thus, the process of step S6 ends.

  A spent fuel assembly stored in the cask is extracted (step S7). The CPU 3 stores the 32 first spent fuel assemblies arranged in the region R1 in the two-region pattern and the 37 second spent fuel assemblies arranged in the region R2 in the memory 4. It is extracted from 5175 spent fuel assemblies (see FIG. 3). This spent fuel assembly is extracted by using a spent fuel assembly that satisfies BU ≦ 30000 MWd / t as the first spent fuel assembly, and a burnup degree as the second spent fuel assembly. Spent fuel assemblies satisfying 30000MWd / t <BU ≤ 35000MWd / t from multiple spent fuel assemblies to be stored in consideration of the burn-up of each spent fuel assembly to be stored A predetermined number of each is extracted.

The radioactivity of the cask when the plurality of extracted spent fuel assemblies are stored is calculated (step S8). The CPU 3 stores all the spent fuel assemblies (for example, 32 first spent fuel assemblies and 37 second spent fuel assemblies) extracted in step S7 in one designated cask. Calculate the radioactivity of the cask. The radioactivity A _all of the cask is obtained by summing up the radioactivity A _i (calculated in step S3) of each of the extracted spent fuel assemblies (for example, 69 spent fuel assemblies). That is, A _all = ΣA _i is calculated.

The calorific value of the cask when the plurality of extracted spent fuel assemblies are stored is calculated (step S9). The CPU 3 stores all the spent fuel assemblies (for example, 32 first spent fuel assemblies and 37 second spent fuel assemblies) extracted in step S7 in one designated cask. The calorific value of the cask at that time is calculated. The calorific value H _{all of the} cask is obtained by summing the calorific values H _i (calculated in step S4) of each extracted spent fuel assembly (for example, 69 spent fuel assemblies). That is, H _all = ΣH _i is calculated.

It is determined whether the radioactivity setting value and the calorific value setting value, which are the specifications of the cask, are satisfied (step S10). The CPU 3 performs the determination at step S10. The radioactivity A _{all of} the cask calculated in step S8 is compared with the radioactivity setting value A _set which is the specification of the cask, and it is determined whether A _all ≦ A _set is satisfied. Further, the calorific value H _all of the cask calculated in step S9 is compared with the calorific value setting value H _set which is the specification of the cask, and it is determined whether or not H _all ≦ H _set is satisfied. When at least one of A _all ≦ A _set and H _all ≦ H _set is not satisfied, the determination in step S10 is “No”. At this time, it is impossible to store a plurality of spent fuel assemblies extracted in step S7 and having a determination of “No” in step S10 into the cask, and are stored again in one cask in step S7. A spent fuel assembly is extracted.

When A _all ≦ A _set and H _all ≦ H _set are satisfied and the determination in step S10 is “Yes”, a plurality of (for example, 69) spent fuel assemblies to be stored in one cask are determined. Is done. These spent fuel assemblies are stored in the memory 4 as one group, for example, with an identification number having a cask.

It is determined whether or not the storage plan of the spent fuel assembly to be stored in the cask has been completed (step S11). In the CPU 3, among the spent fuel assemblies to be stored stored in the memory 4, the range of burnup targeted by the storage pattern selected in step S6 (for example, BU ≦ 35000 MWd / t in the two-region pattern). It is determined whether all the spent fuel assemblies included are grouped in the process of step S7 so that the determination of step S10 is “Yes”. Of all spent fuel assemblies including the burnup range,
When there is a spent fuel assembly that has not been subjected to the process of step S7 so as to satisfy A _all ≦ A _set and H _all ≦ H _set , the determination in step S11 becomes “No”, and those used Steps S7 to S11 are performed on the fuel assembly. When all the spent fuel assemblies included in the target burnup range can be stored in a plurality of casks so as to satisfy A _all ≦ A _set and H _all ≦ H _set , The determination becomes “Yes”.

  Thereafter, the cardinal number of the cask when all the spent fuel assemblies to be stored are stored is determined (step S12). The CPU 3 determines the number of spent fuel assembly groups stored in the memory 4 and assigned with the cask identification number in step S10. The number of this group is the cardinal number of the cask. It is determined whether the cask carry-out base is satisfied (step S13).

It is determined whether or not the cask cardinal number obtained in step S12 is the cask carry-out cardinal number input in step S2. When the determination in step S13 is satisfied (Yes), the number of casks and the spent fuel assembly to be stored for each cask are determined (step S14). The CPU 3 stores a plurality of spent fuel assemblies, and when the card number of the cask satisfying A _all ≦ A _set and H _all ≦ H _set satisfies a predetermined carry-out number, the spent fuel assembly to be stored is stored. The number of casks required to store the fuel and the spent fuel assembly to be stored for each cask are determined. Thus, the CPU 3 stores the identification number of the cask and the fuel IDs of the plurality of spent fuel assemblies stored in the cask having the identification number in the memory 4 in association with each other. Further, the fuel ID of each spent fuel assembly is stored in the memory 4 in association with the region code of the region R1 or R2 in the cask where the fuel ID is disposed.

  Thus, the storage support of the spent fuel assembly for storing the spent fuel assembly to be stored in the cask is completed.

The determination in step S13 is that the determination in step S13 is “when the cardinality of the cask obtained in step S12 is smaller than the cardinality of the cask input in step S2 or when the former cardinal number is larger than the latter cardinality. No. When the determination in step S13 is “No”, the processes in steps S6 to S13 are repeated. Furthermore, when the determination in step S13 is “No”, the CPU 3 determines each information of the plurality of spent fuel assemblies stored for each cask and the spent fuel assemblies having a burnup degree that cannot be stored in the cask. Is input from the memory 4 and output to the display device 6. A spent fuel assembly having a burnup that cannot be stored in the cask is a spent fuel assembly having a burnup satisfying BU> 35000 MWd / t when the two-zone storage pattern is selected.

  There is a case where the cardinal number of the cask obtained in step S12 does not match the cardinal number of the cask carried out. For this reason, in step S13, the cask having the smallest number of spent fuel assemblies to be stored is obtained when the number of cask obtained in step S12 is the number of discharged cask minus one and when the number of discharged cask is +1. Even when the number of bodies is equal to or less than the first set number, it is determined that the cardinal number of the cask obtained in step S12 satisfies the carry-out cardinal number.

  The operator refers again to the information displayed on the display device 6 and re-enters the spent fuel assembly storage pattern selection information from the input device 7 in repeated step S6. When there is a spent fuel assembly having a burnup exceeding 35000 MWd / t, the selection information of the three-region pattern is also input. In this case, a plurality of storage patterns and respective storage patterns to which these storage patterns are applied, such as “the casks to which the two-region pattern is applied and the casks to which the three-region pattern is applied” are used. The cardinal number of the cask may be input to the CPU 3.

The spent fuel assembly extraction process in step S7 is performed again. In the cask to which the three-region pattern is applied, 34 first spent fuel assemblies, 32 second fuel assemblies, and 13 third fuel assemblies are stored in the memory 4 per cask. Each is extracted from the spent fuel assemblies to be stored. After this extraction, the determination in step S10 is performed. When this determination is “Yes” and the determination in step S11 is “No”, steps S7-
The process of S11 is repeated. In a cask that applies a three-region pattern, the radioactivity A _all and the calorific value H _all of the cask are larger than those in a cask that applies a two-region pattern.

Thereafter, when the determination in step S13 is “Yes”, in step S14, the CPU 3 uses the identification number of the cask and a plurality of uses stored in the cask of this identification number for the radix to which the two-region pattern is applied. Associate the fuel ID of the spent fuel assembly, and for the radix to which the three-region pattern is applied, the identification number of the cask to which the three-region pattern is applied and the plurality of spent fuel assemblies to be stored in the cask of this identification number The fuel ID is associated and stored in the memory 4. Further, in the case of the two-region pattern, the fuel ID of each spent fuel assembly is stored in the memory 4 in association with the region code described above. In the case of the three-region pattern, the fuel ID of each spent fuel assembly is stored in the memory 4 in association with the region code of the region R1, R2 or R3 in the cask.

  Even if the three-region pattern is selected, there are some spent fuel assemblies having a burnup in the range of 38000 MWd / t <BU ≦ 41000 MWd / t, and the determination in step S13 is “No”. Sometimes, in step S6, the operator also designates a four-region pattern and inputs the radix of the cask to which this pattern is applied. For the cask to which the four-region pattern is applied, the first, second, third, and fourth fuel assemblies of the respective numbers shown in FIG. Extracted from the aggregate. The corresponding spent fuel assembly is also extracted for each cask to which the two-region pattern and the three-region pattern are separately applied. When the determination in step S13 is “Yes”, in step S14, the CPU 3 determines, for the radix to which the two-region pattern is applied, the identification number of the cask and a plurality of spent fuel sets stored in the cask of this number Associate the fuel ID of the body, and associate the identification number of the cask to which the three-region pattern is applied with the fuel ID of the plurality of spent fuel assemblies stored in the cask of this number with respect to the radix to which the three-region pattern is applied, For the radix to which the four-region pattern is applied, the identification number of the cask to which the four-region pattern is applied and the fuel IDs of the plurality of spent fuel assemblies stored in the cask having this number are associated and stored in the memory 4. Further, in the case of the two-region pattern and the three-region pattern, the fuel ID of each spent fuel assembly is stored in the memory 4 in association with the region code described above. In the case of the four-region pattern, the fuel ID of each spent fuel assembly is stored in the memory 4 in association with the region code of the region R1, R2, R3 or R4 in the cask where the fuel ID is arranged.

  In this embodiment, in order to store a plurality of 8 × 8 BJ type spent fuel assemblies in the cask, the burnup and cooling period of each of these spent fuel assemblies are expressed by Equations (3) and (4). By substituting into, the radioactivity and heat generation amount of each spent fuel assembly are calculated, and the time required for these calculations is shortened.

  In this embodiment, the calculated radioactivity and calorific value of a predetermined number of spent fuel assemblies extracted for storage in one cask are used to set the radioactivity set value that is the specification of the cask. In addition, the number of spent fuel assemblies to be stored is extracted, and the number of casks that satisfy the radioactivity setting value and the heating value setting value is required for carrying out. It is determined whether a predetermined cardinal number of the cask is satisfied. In the present embodiment in which such a determination is made, the time required for the storage plan for determining a plurality of spent fuel assemblies stored in each cask of a predetermined number can be shortened. The number of man-hours required to implement this storage plan can also be reduced.

  In this embodiment, it is necessary to determine a plurality of spent fuel assemblies to be stored in each cask of a predetermined number including the time required for calculating the radioactivity and calorific value of each spent fuel assembly. Time can be shortened.

  In this embodiment, the time required for determining a plurality of spent fuel assemblies to be stored in each cask of a predetermined number is calculated using a conventional calculation code when 5000 spent fuel assemblies are targeted. Can be reduced to about 1/1000 as compared to the time required for the conventional storage plan for a plurality of spent fuel assemblies including calculating the radioactivity and calorific value of each spent fuel assembly. .

  In the present embodiment, the efficiency of storing the spent fuel assembly in the cask can be increased because of the determination as described above. This embodiment can increase the storage efficiency of the spent fuel assemblies in the cask by about 10%, compared with the conventional storage plan for a plurality of spent fuel assemblies. When the cask having enhanced storage efficiency of the spent fuel assemblies is carried in and stored in the intermediate storage facility, the storage efficiency of the spent fuel assemblies in the intermediate storage facility can be increased.

  In this embodiment, information on a plurality of spent fuel assembly storage patterns having a plurality of storage areas in which used fuel assemblies having different burnup ranges are respectively arranged and having different numbers of storage areas is prepared. Since one spent fuel assembly storage pattern can be selected from these spent fuel assembly storage patterns, the spent fuel assembly that can be stored in the cask even if there is a spent fuel assembly with a high degree of combustion. You can make a storage plan for your body. Therefore, more spent fuel assemblies to be stored can be stored in the cask, and the number of used fuel assemblies that cannot be stored in the cask can be reduced.

  In this embodiment, the time required for the storage plan of the spent fuel assemblies in a plurality of casks can be shortened as compared with Japanese Patent Laid-Open No. 2008-232718, and the spent fuel assemblies can be stored in the casks. Efficiency can be improved.

  The data processing device 2 that executes the processing shown in FIG. 2 is functionally equivalent to the data processing device 2A shown in the hardware configuration shown in FIG. The data processing apparatus 2A includes a first radioactivity calculation unit 8, a first calorific value calculation unit 9, a storage pattern selection unit 10, a spent fuel assembly selection unit 11, a second radioactivity calculation unit 12, and a second calorific value calculation. Means 13, radioactivity / heat generation determination means 14, cask cardinal number determination means 15, stored spent fuel assembly determination means 16, memory 4 and input / output interface 5.

  The input / output interface 5 is connected to the first radioactivity calculation means 8, the first calorific value calculation means 9, the storage pattern selection means 10, and the memory 4. First radioactivity calculation means 8 is connected to second radioactivity calculation means 12. The first heat generation amount calculation means 9 is connected to the second heat generation amount calculation means 13. The spent fuel assembly selection unit 11 is connected to the storage pattern selection unit 10 and the radioactivity / heat generation amount determination unit 14. Radioactivity / heat generation amount determination means 14 is connected to second radioactivity calculation means 12 and second heat generation amount calculation means 13. The cask cardinal number determination means 15 is connected to the storage pattern selection means 10, the radioactivity / heat generation amount determination means 14, and the stored spent fuel assembly determination means 16. The memory 4 includes first radioactivity calculation means 8, first heat value calculation means 9, storage pattern selection means 10, spent fuel assembly selection means 11, second radioactivity calculation means 12, and second heat value calculation means 13. The radioactivity / heat generation amount determining means 14, the cask cardinal number determining means 15 and the stored spent fuel assembly determining means 16 are connected.

  A spent fuel assembly storage support device 1A shown in FIG. 7 is equivalent to the spent fuel assembly storage support device 1, and includes a data processing device 2A, a display device 6, and an input device 7. A display device 6 and an input device 7 are connected to the input / output interface 5.

  Input of each information in steps S1, S2 and S5 shown in FIG. 2 is performed by the input device 7, and each input information is stored in the memory 4. The first radioactivity calculation means 8 performs the process of step S3 shown in FIG. 2, and the first calorific value calculation means 9 performs the process of step S4 shown in FIG. The storage pattern selection means 10 executes the process of step S6 shown in FIG. The spent fuel assembly selection means 11 executes the process of step S7 shown in FIG. 2 using the storage pattern information selected by the storage pattern selection means 10.

  The second radioactivity calculation means 12 performs the process of step S8 shown in FIG. 2, and the second calorific value calculation means 13 performs the process of step S9 shown in FIG. The radioactivity / heat generation determination means 14 performs the determination in step S10 shown in FIG. 2, and when this determination is "No", the spent fuel stored in one cask by the spent fuel assembly selection means 11 is used. Redo the collection extraction. The spent fuel assembly selection unit 11 stores a plurality of spent fuel assemblies to be stored for each cask until the determination in step S11 executed by the radioactivity / heat generation determination unit 14 becomes “Yes”. Extract.

  When the determination in step S11 executed by the radioactivity / heat generation determination means 14 is "Yes", the cask radix determination means 15 executes the processes of steps S12 and S13 shown in FIG. The cask cardinal number determining means 15 executes the processing of step S12, and obtains the number of spent fuel assembly groups to which the cask identification number is assigned in step S10, that is, the cask cardinal number. The cask cardinal number determining means 15 determines whether or not the cask cardinal number satisfies the cask carry-out cardinal number input in step S2. When this determination is “No”, the storage pattern selection unit 10 selects other storage patterns, for example, and selects the spent fuel assembly selection unit 11, the second radioactivity calculation unit 12, and the second calorific value calculation unit. 13. The processing in the radioactivity / heat generation determination means 14 and the cask radix determination means 15 is performed again. When the determination in step S13 in the cask radix determination means 15 is "Yes", the stored spent fuel assembly determination means 16 executes the process of step S14 shown in FIG. A spent fuel assembly is determined for each cask.

  The spent fuel assembly storage support apparatus 1 </ b> A can also obtain the effects produced by the spent fuel assembly storage support apparatus 1.

  A method for storing spent fuel assemblies in a cask according to another embodiment of the present invention will be described with reference to FIG. The storage method of the present embodiment is an example applied to a boiling water nuclear power plant.

  The fuel assembly storage device used in the storage method of this embodiment will be described with reference to FIG. The fuel assembly storage device 20 includes a fuel transfer device 21 and a control device 25. The fuel transfer device 21 includes a traveling carriage 22, a traversing carriage 23, and a fuel gripping device (not shown). The traveling carriage 22 extends in one direction (referred to as X direction) in the fuel storage pool 29 and is movably disposed on guide rails 28A and 28B provided on the operation floor with the fuel storage pool 29 interposed therebetween. The traveling carriage 22 is moved in the X direction by a first drive device (not shown) provided on the traveling carriage 22. The traversing carriage 23 is arranged on a pair of guide rails (not shown) installed on the traveling carriage 22 in the longitudinal direction of the traveling carriage 22. The transverse carriage 23 is moved in the Y direction orthogonal to the X direction by a second drive device (not shown) provided on the transverse carriage 23. The fuel gripping device is attached to the traverse carriage 23 and has a fuel grip portion (not shown) for gripping the spent fuel assembly. The fuel gripping part grips the spent fuel assembly and is moved in the vertical direction by a third drive device (not shown) provided in the traverse carriage 23. As the fuel transfer device 21, a fuel exchanger that is usually used for fuel replacement in a boiling water nuclear power plant is used. The fuel storage pool 29 shown in FIG. 12 shows a state viewed from above.

  The control device 25 and the storage device 26 are arranged in a fuel control room 24 provided on the operation floor in the reactor building. The storage device 26 is connected to the control device 25.

  In the boiling water nuclear power plant, the fuel storage pool 29 is disposed above the reactor containment vessel that houses the reactor in the reactor building. A fuel storage rack 30 is installed in the fuel storage pool 29. The fuel storage pool 29 is filled with cooling water, and the fuel storage rack 30 is disposed in the cooling water. The spent fuel assembly 31 taken out from the reactor is raised to the same level as the fuel storage pool 29 in a reactor well (not shown) above the reactor, moves in the horizontal direction, and passes through the gate 32. It is transferred into the fuel storage pool 29. Further, the spent fuel assembly 31 is inserted into a predetermined position of the fuel storage rack 30, for example, a position P1 (X1, Y1) and stored. While being stored, it is cooled by cooling water in the fuel storage rack 30. The removal of the spent fuel assembly 31 from the reactor and the transfer to the predetermined position are performed by the fuel transfer device 21 that is a fuel changer controlled by the control device 25. The control device 25 controls the driving and stopping of each of the first driving device, the second driving device, and the third driving device. The traveling carriage 22, the transverse carriage 23, and the fuel gripper are moved in a predetermined direction by their control.

  A fuel ID is assigned to each spent fuel assembly in the fuel storage pool 29 in order to recognize the individual spent fuel assembly. By using this fuel ID, information such as the burn-up level and the point in time (year / month / day) when the fuel is stored in the fuel storage pool 29 and the storage position in the fuel storage pool 29 are managed for each spent fuel assembly. be able to. Such information for each spent fuel assembly is stored in the storage device 26. Information on the storage position of each spent fuel assembly in the fuel storage pool 29 can be obtained by each encoder provided in each of the first drive device and the second drive device.

  Information on the position in the fuel storage rack 30 in which the spent fuel assemblies taken out from the nuclear reactor are stored, for example, the position P1 (X1, Y1), is also obtained by the encoders described above. Information on the position P1 (X1, Y1) is also stored in the storage device 26 in association with the fuel ID. Each spent fuel assembly stored in the fuel storage rack 30 is searched for information stored in the storage device 26 with the corresponding fuel ID, so that the spent fuel assembly to which the fuel ID is assigned is searched. The degree of burnup and the point of time when the fuel is stored in the fuel storage pool 29 can be obtained.

  In the fuel storage pool 29, for example, a cask pit 33 is provided at one corner. The cask pit 33 is surrounded by a concrete side wall except for the opening 34. A cask (for example, a metal cask) 35 in which the spent fuel assembly 31 is stored is disposed in the cooling water in the cask pit 33.

  Taking a case where the spent fuel assembly 31 is stored in the cask 35 as an example, a method for storing the spent fuel assembly in the cask will be described below. Using the spent fuel assembly storage support apparatus 1 (see FIG. 12) described in the first embodiment, a storage plan for the spent fuel assembly 31 is executed by the processing procedure shown in FIG. 2, that is, steps S1 to S14. A plurality (for example, 5175) of spent fuel assemblies 31 to be stored in each of the plurality of (for example, 75) casks 35 are determined. As a result, the spent fuel assembly storage support apparatus 1 uses the cask identification number, each fuel ID of the plurality of spent fuel assemblies 31 to be stored, and R1 and R2 in which the spent fuel assembly 31 is arranged in the cask. Spent fuel assembly storage information including a region code such as can be obtained for each cask. In the spent fuel assembly storage support apparatus 1, the CPU 3 registers the spent fuel assembly storage information related to a plurality of casks stored in the memory 4 in the CD-ROM 27.

  It is assumed that, for example, two boiling water nuclear plants, Unit 1 and Unit 2, are installed in the nuclear power plant where the above boiling water nuclear plant is installed. The spent fuel assembly storage information registered in the CD-ROM 27 is input to the control devices 25 of the two boiling water nuclear power plants and registered in the storage device 26.

  In the two boiling water nuclear power plants, it is assumed that the operation of housing the spent fuel assembly 31 in the cask 35 is performed. When a plurality of spent fuel assemblies 31 stored in one cask 35 are respectively stored in the fuel storage pools 29 of these boiling water nuclear power plants, the spent fuel assembly into the cask 35 is stored. A plurality of uses in which spent fuel assemblies are transported between the fuel storage pools of these boiling water nuclear power plants and stored in one cask 35 using the fuel transport container before the storage operation of the body 31 is performed. The spent fuel assembly is gathered in the fuel storage pool 29 of one boiling water nuclear plant.

  In the two boiling water nuclear power plants, the spent fuel assemblies are stored in the cask 35 in parallel using the spent fuel assembly storage information. The spent fuel assembly storage operation performed in one boiling water nuclear power plant will be described as a representative.

  An empty cask 35 of the type specified in step S5 described above is placed in the cask pit 33. The control device 25 stores the identification number of one cask, the fuel IDs of the plurality of spent fuel assemblies 31 corresponding to the identification number, and the area codes of the spent fuel assemblies 31 corresponding to the identification number. Enter from. The control device 25 controls each traveling fuel assembly 31 to be stored in the cask 35 based on these fuel IDs to control the traveling carriage 22, the transverse carriage 23, and the fuel gripping apparatus, and stores them in the fuel storage rack 30. The corresponding spent fuel assemblies 31 are sequentially grasped by the fuel grasping portion and transferred to the position of the cask 35 by the movement of the traveling carriage 22 and the transverse carriage 23. These spent fuel assemblies 31 are sequentially stored in a predetermined area in the cask 35 designated by the area code.

  The cask 35 in which all the corresponding spent fuel assemblies 31 are stored in a predetermined area is drawn out from the cask pit 33 using an overhead crane (not shown) in the reactor building, It is transported to the position. At that position, the cooling water in the cask 35 is discharged, a lid is attached to the upper end of the outer trunk, and the cask 35 is sealed.

  The above-described storage operation of the spent fuel assembly 31 in the cask 35 is performed on a predetermined number of casks 35. The cask 35 in which the spent fuel assembly 31 is accommodated and sealed is stored from a nuclear power plant, for example, to an intermediate storage facility and stored in the intermediate storage facility until it is transferred to a reprocessing facility. .

  Also in this embodiment, since the storage plan for the spent fuel assemblies in the cask is made in advance using the spent fuel assembly storage support device 1, each effect produced in the first embodiment can be obtained. Since the storage efficiency of the spent fuel assembly 31 in the cask 35 is improved, the storage efficiency of the spent fuel assembly 35 in the intermediate storage facility is improved.

  The spent fuel assembly storage support device 1 may be connected to the control device 25 with a signal transmission line. In such a configuration, the spent fuel assembly storage information created by the spent fuel assembly storage support device 1 can be input to the control device 25 via the signal transmission line instead of the CD-ROM 27.

  Also in other nuclear power plants such as a pressurized nuclear power plant, the spent fuel assembly is stored in the cask using the spent fuel assembly storage information created by the spent fuel assembly storage support device 1. be able to.

  The present invention can be applied to a storage operation of a spent fuel assembly in a storage container.

  DESCRIPTION OF SYMBOLS 1,1A ... Spent fuel assembly storage assistance device, 2, 2A ... Data processing device, 3 ... Central processing device, 4 ... Memory, 8 ... First radioactivity calculation means, 9 ... First calorific value calculation means, 10 ... Storage pattern selection means, 11 ... Spent fuel assembly selection means, 12 ... Second radioactivity calculation means, 13 ... Second heat generation amount calculation means, 14 ... Radioactivity / heat generation amount determination means, 15 ... Cask base number determination means , 16 ... Storage spent fuel assembly determining means, 20 ... Fuel assembly storage device, 21 ... Fuel transfer device, 22 ... Traveling carriage, 23 ... Traverse carriage, 24 ... Fuel control room, 25 ... Control device, 29 ... Fuel Storage pool, 31 ... spent fuel assembly, 35 ... cask.

Claims (5)

When the burnup of the spent fuel assembly taken out of the boiling water reactor, stored in the cask, is BU, the cooling period is CT, and the constants are α1, α2, β1, and β2, the spent fuel assembly is in the radioactivity a is the following (1), the calorific value H of the spent fuel assemblies are respectively represented by the following equation (2), and is housed in the cask of the specified plurality groups in case a plurality of the spent fuel assemblies accommodated object is either 8 × 8BJ types of spent fuel assemblies and step II-type spent fuel assemblies,
When the spent fuel assemblies stored in the cask are the 8 × 8 BJ type spent fuel assemblies, the plurality of spent fuels to be stored stored in the designated plurality of casks For each 8 × 8 BJ type spent fuel assembly that is an assembly , the radioactivity A and the calorific value H are the constant α1, 2.59, the constant α2, 0.0068, and the constant β1, respectively. Equations (1) and (2) substituting 0.0283 and 0.0188 which is the constant β2, and the burnup BU and the cooling period CT of each of the 8 × 8 BJ type spent fuel assemblies. out Risan by a processor by using, when the spent fuel assemblies to be accommodated in the cask is spent fuel assemblies in the step II, it is housed in the cask of the specified plurality groups , Storage vs. For each of the spent fuel assemblies of Step II, which are the plurality of spent fuel assemblies of an elephant, the radioactivity A and the calorific value H are set to 2.68 which is the constant α1 and 0.8 which is the constant α2. [0077] Equation (1) in which the constant β1 0.0243 and the constant β2 0.0243, the burnup BU of the Step II type spent fuel assembly, and the cooling period CT are substituted. (2) the first step of de San by the arithmetic processing unit using a formula,
The plurality of spent fuel assemblies that are one of the 8 × 8 BJ type spent fuel assemblies and the step II type spent fuel assemblies to be stored in the cask are processed by the arithmetic processing unit. A second step of selecting from a plurality of spent fuel assemblies to be stored;
The radioactivity of the cask when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is determined by the processing unit using each of the selected spent fuel assemblies. third step of calculating using said radioactivity calculated in the first step with respect to,
The calorific value of the cask when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is calculated by the arithmetic processing unit using the arithmetic processing unit. fourth steps of calculating by using the calorific value calculated in the first step for each,
When the plurality of selected spent fuel assemblies calculated in the third step are stored in all the storage areas in the cask, the radioactivity of the cask is less than or equal to the set radioactivity of the cask. The amount of heat generated by the cask when the plurality of selected spent fuel assemblies calculated in the fourth step are stored in all the storage areas in the cask, calculated in the fourth step. A fifth step of determining, by the arithmetic processing unit, whether or not a second determination condition of being equal to or less than a set calorific value of the cask is satisfied;
In the determination of the fifth step, it is determined that the first determination condition and the second determination condition are satisfied, and the storage plan of all the plurality of spent fuel assemblies to be stored in the cask is completed. when radix of the cask in which the selected plurality of spent fuel assemblies are accommodated, by the processor, the steps of the sixth step of determining whether to satisfy the specified plurality groups Implemented ,
In the fifth step, when it is determined by the arithmetic processing unit that at least one of the first determination condition and the second determination condition is not satisfied, another plurality of items stored in the cask in the second step Selection of the spent fuel assembly, calculation of the radioactivity and the calorific value in the third step and the fourth step with respect to the selected other plurality of spent fuel assemblies, and the selected The determination in the fifth step for the cask containing another plurality of spent fuel assemblies is performed until it is determined in the fifth step that the first determination condition and the second determination condition are satisfied,
When it is determined in the sixth step that the radix of the cask that is equal to or less than the radioactivity setting value and the calorific value setting value does not satisfy the specified plural groups, the second step, The third step, the fourth step, the fifth step, and the sixth step are executed until it is determined in the sixth step that the cardinality of the cask satisfies the specified plurality of groups,
In the sixth step, when it is determined that the number of casks that are equal to or less than the radioactivity setting value and the calorific value setting value satisfies the specified plurality, a plurality of items stored for each cask. The spent fuel assembly storage support method, wherein the spent fuel assembly is determined.
A = α1 · BU · e ^{−β1 · CT} (1)
H = α2 · BU · e ^{−β2 · CT} (2) Based on the information inputted by the input device, the spent fuel assembly storage pattern having a plurality of the storage area where the spent fuel assemblies range of burnup is different are disposed respectively, by the processing unit, 2. The method for supporting storage of spent fuel assemblies according to claim 1, wherein the selection of the spent fuel assemblies in the second step is performed for each storage region. When the plurality of selected spent fuel assemblies calculated in the third step are stored in all the storage areas in the cask, the first of the selected plurality of spent fuel assemblies is selected. A plurality of the first spent fuel assemblies having a burnup within a range of 1 burnup are stored in the first storage region in the cask and larger than the first burnup range. A plurality of second spent fuel assemblies having a burn-up within a range of a second burn-up that is a burn-up are stored in the second storage region in the cask, and in the cask The spent fuel assembly storage support method according to claim 1, wherein the plurality of first spent fuel assemblies surround the plurality of second spent fuel assemblies . When the burnup of the spent fuel assembly taken out of the boiling water reactor, stored in the cask, is BU, the cooling period is CT, and the constants are α1, α2, β1, and β2, the spent fuel assembly is in the radioactivity a is the following (1), the calorific value H of the spent fuel assemblies are respectively represented by the following equation (2), and is housed in the cask of the specified plurality groups in case a plurality of the spent fuel assemblies accommodated object is either 8 × 8BJ types of spent fuel assemblies and step II-type spent fuel assemblies,
When the spent fuel assemblies stored in the cask are the 8 × 8 BJ type spent fuel assemblies, the plurality of spent fuels to be stored stored in the designated plurality of casks For each 8 × 8 BJ type spent fuel assembly that is an assembly , the radioactivity A is set to 2.59 that is the constant α1, 0.0283 that is the constant β1, and each 8 × 8 BJ type. The spent fuel assembly calculated by using the equation (1) in which the burnup BU and the cooling period CT of the spent fuel assembly are substituted, and the spent fuel assembly stored in the cask is the step II type spent fuel assembly. A radioactivity A for each of the spent fuel assemblies of Step II, which are the plurality of spent fuel assemblies to be stored, stored in the designated plurality of casks. Constant α1 2.68 and 0.0243, which is the constant β1, the first burntability BU and the cooling period CT of each of the step II type spent fuel assemblies are calculated using the first equation (1) . Radioactivity calculation means;
When the spent fuel assemblies stored in the cask are the 8 × 8 BJ type spent fuel assemblies, the plurality of used fuels to be stored and stored in the plurality of designated casks. For each 8 × 8 BJ type spent fuel assembly that is a fuel assembly , the calorific value H is 0.0068 that is the constant α2, 0.0188 that is the constant β2, and each 8 × 8 BJ type. The plurality of used fuels to be stored are stored in the specified plurality of casks, calculated using the equation (2) substituting the burn-up BU and the cooling period CT of the used fuel assembly. For each Step II type spent fuel assembly which is a fuel assembly, the calorific value H is set to 0.0077 which is the constant α2, 0.0243 which is the constant β2, and the use of each Step II type. A first calorific value calculation means for calculating by using the substituting the burnup BU and the cooling period CT of spent fuel assemblies (2),
Multiple to be stored in the cask, a plurality of spent fuel assemblies is either spent fuel assemblies and the step type II spent fuel assemblies of the 8 × 8BJ type, and the receiving object A spent fuel assembly selecting means for selecting from the spent fuel assemblies of
The selected use, wherein the radioactivity of the cask when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is calculated by the first radioactivity calculation means. Second radioactivity calculation means for calculating using the radioactivity of each of the spent fuel assemblies;
The selected calorific value of the cask when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is calculated by the first calorific value calculation means. Second calorific value calculation means for calculating the calorific value of each spent fuel assembly;
The radioactivity of the cask calculated by the second radioactivity calculation means when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is the set radiation of the cask. When the plurality of selected spent fuel assemblies calculated by the second determination unit and the second calorific value calculation unit are stored in all the storage regions in the cask. Radioactivity / heat generation determination means for determining whether the second condition that the calorific value of the cask is equal to or less than a set calorific value of the cask is satisfied;
In the radioactivity / heat generation amount determining means, it is determined that the first determination condition and the second determination condition are satisfied, and a storage plan of all the plurality of spent fuel assemblies to be stored in the cask is determined. A cask radix determination means for determining whether the radix of the cask in which the selected plurality of spent fuel assemblies are accommodated satisfies the specified plural groups when finished ,
When the cask cardinal number determining means determines that the cardinality of the cask that is less than or equal to the radioactivity setting value and the calorific value setting value satisfies the specified plural groups, the cask is determined for each cask. A spent fuel assembly determining means for determining a plurality of spent fuel assemblies ,
When it is determined by the radioactivity / heat generation amount determination means that at least one of the first determination condition and the second determination condition is not satisfied, the spent fuel assembly selection means stores another in the cask. Selection of a plurality of the spent fuel assemblies, calculation of the radioactivity and the calorific value by the second radioactivity calculation means and the second calorific value calculation means for the selected other plural spent fuel assemblies. And the determination by the radioactivity / calorific value determination means for the cask containing the plurality of selected other spent fuel assemblies is performed by the radioactivity / calorific value determination means in the first determination condition and the first 2 It is performed until it is determined that the determination condition is satisfied,
When it is determined by the cask base number determining means that the base number of the cask that is less than or equal to the radioactivity set value and the calorific value set value does not satisfy the specified plurality, the spent fuel set Selection of the plurality of spent fuel assemblies to be stored in the cask by body selection means, calculation of the radioactivity and calorific value by the second radioactivity calculation means and the second calorific value calculation means, the radioactivity - the determination by the determination and said cask base determination means according to the heat generation amount determining means, is executed until the radix of the cask in the cask base determination means is determined to satisfy a plurality radical which is the designated Rukoto A storage support device for spent fuel assemblies characterized by the above.
A = α1 · BU · e ^{−β1 · CT} (1)
H = α2 · BU · e ^{−β2 · CT} (2) When the burnup of the spent fuel assembly taken out of the boiling water reactor, stored in the cask, is BU, the cooling period is CT, and the constants are α1, α2, β1, and β2, the spent fuel assembly is in the radioactivity a is the following (1), the calorific value H of the spent fuel assemblies are respectively represented by the following equation (2), and is housed in the cask of the specified plurality groups in case a plurality of the spent fuel assemblies accommodated object is either 8 × 8BJ type spent fuel assemblies and step II-type spent fuel assemblies,
When the spent fuel assemblies stored in the cask are the 8 × 8 BJ type spent fuel assemblies, the plurality of spent fuels to be stored stored in the designated plurality of casks For each 8 × 8 BJ type spent fuel assembly that is an assembly , the radioactivity A and the calorific value H are the constant α1, 2.59, the constant α2, 0.0068, and the constant β1, respectively. Equations (1) and (2) substituting 0.0283 and 0.0188 which is the constant β2, and the burnup BU and the cooling period CT of each of the 8 × 8 BJ type spent fuel assemblies. out Risan by a processor by using, when the spent fuel assemblies to be accommodated in the cask is spent fuel assemblies in the step II, it is housed in the cask of the specified plurality groups , Storage vs. For each of the spent fuel assemblies of Step II, which are the plurality of spent fuel assemblies of an elephant, the radioactivity A and the calorific value H are set to 2.68 which is the constant α1 and 0.8 which is the constant α2. [0077] Equation (1) in which the constant β1 0.0243 and the constant β2 0.0243, the burnup BU of the Step II type spent fuel assembly, and the cooling period CT are substituted. (2) the first step of de San by the arithmetic processing unit using a formula,
The plurality of spent fuel assemblies that are one of the 8 × 8 BJ type spent fuel assemblies and the step II type spent fuel assemblies to be stored in the cask are processed by the arithmetic processing unit. A second step of selecting from a plurality of spent fuel assemblies to be stored;
The radioactivity of the cask when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is determined by the processing unit using each of the selected spent fuel assemblies. third step of calculating using said radioactivity calculated in the first step with respect to,
The calorific value of the cask when the plurality of selected spent fuel assemblies are stored in all the storage areas in the cask is calculated by the arithmetic processing unit using the arithmetic processing unit. fourth steps of calculating by using the calorific value calculated in the first step for each,
When the plurality of selected spent fuel assemblies calculated in the third step are stored in all the storage areas in the cask, the radioactivity of the cask is less than or equal to the set radioactivity of the cask. The amount of heat generated by the cask when the plurality of selected spent fuel assemblies calculated in the fourth step are stored in all the storage areas in the cask, calculated in the fourth step. A fifth step of determining, by the arithmetic processing unit, whether or not a second determination condition of being equal to or less than a set calorific value of the cask is satisfied; and
In the determination of the fifth step, it is determined that the first determination condition and the second determination condition are satisfied, and the storage plan of all the plurality of spent fuel assemblies to be stored in the cask is completed. when radix of the cask in which the selected plurality of spent fuel assemblies are accommodated, by the processor, the steps of the sixth step of determining whether to satisfy the specified plurality groups Implemented ,
In the fifth step, when it is determined by the arithmetic processing unit that at least one of the first determination condition and the second determination condition is not satisfied, another plurality of items stored in the cask in the second step Selection of the spent fuel assembly, calculation of the radioactivity and the calorific value in the third step and the fourth step with respect to the selected other plurality of spent fuel assemblies, and the selected The determination in the fifth step for the cask containing another plurality of spent fuel assemblies is performed until it is determined in the fifth step that the first determination condition and the second determination condition are satisfied,
When it is determined in the sixth step that the radix of the cask that is equal to or less than the radioactivity setting value and the calorific value setting value does not satisfy the specified plural groups, the second step, The third step, the fourth step, the fifth step, and the sixth step are executed until it is determined in the sixth step that the cardinality of the cask satisfies the specified plurality of groups,
In the sixth step, when it is determined that the number of casks that are equal to or less than the radioactivity setting value and the calorific value setting value satisfies the specified plurality, a plurality of items stored for each cask. Determining the spent fuel assembly of
Based on the determined information of the spent fuel assembly to be stored for each cask, the spent fuel assembly in the fuel storage pool is stored in the cask. How to store your body.
A = α1 · BU · e ^{−β1 · CT} (1)
H = α2 · BU · e ^{−β2 · CT} (2)

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