KR20200011277A - Apparatus and method for analyzing crud in a nuclear reator - Google Patents

Abstract

The present invention relates to a device for analyzing a chalk river unidentified deposit (CRUD) in a nuclear reactor. The device for analyzing the CRUD in the nuclear reactor comprises: an output measurement unit measuring an output of a nuclear fuel assembly in the nuclear reactor for each operation cycle of the nuclear reactor; a CRUD analysis unit analyzing CRUD information in the nuclear reactor based on the output of the nuclear fuel assembly in a previous operation cycle for each operation cycle; and an operation condition setting unit setting an operation condition of the nuclear reactor in a next operation cycle for the nuclear fuel assembly by using the CRUD information.

Description

Reactor Clad Analysis Apparatus and Method {APPARATUS AND METHOD FOR ANALYZING CRUD IN A NUCLEAR REATOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to the CRK (Chalk River Unidentified Deposit, CRUD), and in particular, modeling and modeling in-reactor clad information based on the output of the reactor according to the combustion of the fuel assembly during the operation cycle immediately before the reactor is operated. The present invention relates to an apparatus and method for analyzing nuclear reactor reactors by which operating conditions of the next operation cycle of a nuclear reactor can be increased based on the obtained crude information.

In general, in order to increase the economical efficiency of the pressurized water reactor (PWR), as long cycle, high power, and high combustion operation are performed, the amount of corrosion on the surface of the nuclear fuel cladding and the amount of adhesion of the corroded product are increasing. The problem is that the output of the reactor is reduced.

Axial Offset Anomaly (AOA) is defined as the difference in output distribution between the top and bottom of the nuclear fuel assembly, that is, when the axial offset is more than 3% from the expected output distribution. As a representative phenomenon, the clad attached to the surface of the fuel assembly is known as the main cause.

Therefore, it is necessary to predict and minimize the generation of such crudes, but it is difficult to accurately analyze the reactors because it is impossible to analyze the amount of generated crudes and the material distribution of the crudes at the current technology level. It does not solve the problem of output reduction.

(Patent literature)

Republic of Korea Patent Publication No. 10-2018-0035725 (published April 06, 2018)

Therefore, in an embodiment of the present invention, in-reactor crude information is modeled on the basis of the output of the reactor according to combustion of the fuel assembly in the operation cycle immediately before operation of the reactor, and the next operation of the reactor based on the modeled crude information. It is an object of the present invention to provide an apparatus and method for analyzing nuclear reactor reactors that can increase reactor operation efficiency by setting operating conditions of cycles.

An apparatus for analyzing a nuclear reactor reactor according to an embodiment of the present invention described above, comprising: an output measuring unit measuring an output of the nuclear reactor fuel assembly at each operation cycle of the reactor; and the fuel at the previous operation cycle for each operation cycle. And a crude analyzer configured to analyze the nuclear reactor nuclear reactor information based on the output of the aggregate, and an operating condition setter configured to set operating conditions of the nuclear reactor in the next operation cycle for the fuel assembly using the crude information. do.

In addition, the output of the fuel assembly is an axial output distribution signal (ASI), the crude analyzer, in analyzing the crude information, based on the axial output distribution signal of the generated crude in the reactor It is characterized by predicting the amount and concentration of boron contained in the clad.

The crude analyzer may generate a basic axial output distribution signal in an environment without the clad, and the axial output distribution value at each combustion time point for the fuel assembly may correspond to the basic axial output distribution signal. The amount of the clad and the concentration of the boron which are maximally converged to the value of the axial output distribution at each combustion point on the direction output distribution signal are characterized.

The operation condition setting unit may set an operation condition of the reactor of the next operation period based on the predicted amount of the crad and the concentration value of boron in the reactor.

In addition, as a method for analyzing a nuclear reactor nuclear reactor according to an embodiment of the present invention, the step of measuring the output of the nuclear fuel assembly in each of the operating cycle of the reactor, and the fuel assembly in the previous operation cycle for each of the operation cycle Analyzing the in- reactor crude information based on the output, and setting operating conditions of the reactor in a next operation cycle for the fuel assembly using the crude information.

In addition, the output of the fuel assembly is an axial output distribution signal (ASI), and the analyzing step, based on the axial output distribution signal of the amount of the crude generated in the reactor and the boron contained in the It is characterized in that the step of predicting the concentration.

The predicting may include generating a basic axial output distribution signal in an environment without the clad, and an axial output distribution value at each combustion time point for the fuel assembly on the basic axial output distribution signal. And predicting the amount of the clad and the concentration of boron such that the axial power distribution signal converges to the axial power distribution value at each combustion point as much as possible.

The setting of the operating condition may include setting operating conditions of the reactor of the next operation period based on the predicted amount of the crude in the reactor and the concentration value of boron.

According to an embodiment of the present invention, in the reactor nuclear reactor analysis, modeling the reactor information on the basis of the reactor output according to the combustion of the fuel assembly in the operating cycle immediately before the operation of the reactor, and modeled Based on the information, the operating conditions of the next operating cycle of the reactor can be set to increase reactor operating efficiency.

1 is a detailed block diagram of a reactor clad analysis apparatus according to an embodiment of the present invention.
2 is a graphical illustration of axial output distribution signals under various conditions in accordance with one embodiment of the present invention.
Figure 3 is an exemplary view of the appearance of the generation of fuel on the fuel assembly according to an embodiment of the present invention.
4 is an operation control flowchart of the reactor clad analysis apparatus according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted when it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Figure 1 shows a detailed block diagram of the reactor clad analysis apparatus according to an embodiment of the present invention.

First, the pressurized water reactor 100 may be formed of a cylindrical pressure vessel formed vertically.

Inside the reactor 100, a nuclear reactor core 102 in which a nuclear fuel rod is loaded is located. At this time, such a fuel assembly 102 is composed of a plurality of nuclear fuel rods (fissile material), it is located in the lower portion of the reactor 100 can be implemented in a state that is generally contained in cooling water, such as light water (H2O).

A central vertical centralizer (104) is disposed concentrically within the reactor 100, for example, to allow the coolant heated by the fuel assembly 102 to move to the top of the pressure vessel 100.

The steam generator 106 is formed to surround the central vertical tube 104 between the lower space 110 and the upper space 112 inside the reactor 100.

The steam generator 106 includes a plurality of tubes 108, each tube 108 being configured to move coolant from the upper space 112 of the reactor 100 to the lower space 110. Therefore, when the operation of the fuel assembly 102 is started, the coolant heated by the fuel assembly 102 is moved to the top of the reactor 100 through the central vertical tube 104 and to the top of the reactor 100. The coolant may be moved to the bottom of the reactor 100 through the tube 108 of the steam generator 106 again. Therefore, the heated cooling water is generated as steam through the tube 108 and applied to a turbine (not shown) outside the reactor 100 to perform power generation.

Next, the reactor crude analysis device 150 according to an embodiment of the present invention analyzes the crude information generated by combustion in the fuel assembly 102 in the reactor as described above. As shown in FIG. 1, the crude analyzer 150 may include an output measuring unit 152, a crude analyzing unit 154, an operation condition setting unit 156, and the like.

The output measuring unit 152 measures the output of the reactor 100 generated by the combustion of the fuel assembly 102 for each driving cycle.

In this case, for example, when the fuel assembly 102 has a use period of three years and each driving cycle of the reactor 100 is one year, the total driving cycle of the fuel assembly 102 may be three driving cycles.

In addition, the output of the nuclear reactor measured from the output measuring unit 152 may be, for example, an axial output distribution signal (ASI) as shown in FIG. 2, but is not limited thereto.

At this time, the axial output distribution signal as described above may be calculated as shown in [Equation 1] below, and if the value of the axial output distribution signal is "+", the lower side of the fuel assembly 102 is burned a lot. If "-" indicates that the upper side of the fuel assembly is a lot of combustion.

Referring to FIG. 2, the basic axial output distribution signal 200 in an environment without a clad is uniformly combusted between the upper and lower portions of the nuclear fuel assembly 102 in the reactor 100, and thus the fuel assembly 102 on the axial output distribution signal. It can be seen that the value of the axial output distribution at each burnup point of) is formed around " 0 ".

However, if the reactor 100 is actually operated, referring to the axial power distribution signal 204 which is actually measured as the generation of the creed in the reactor 100 as the fuel assembly 102 burns, the axial power distribution The axial power distribution value at each burnup of the fuel assembly 102 on the signal 204 is + or ?? It can be seen that a large variation occurs in the direction.

That is, referring to the axial output distribution signal 204 actually measured in the reactor 100, the initial value of the combustion of the fuel assembly 102 was a "-" value, and as the combustion of the fuel assembly 102 proceeded, "+". You can see that it is changed to "-" after changing to the value. The reason why the value of the axial output distribution is changed is that the upper part is combusted more in the initial stage of combustion of the fuel assembly 102 due to the clad generated by the combustion of the fuel assembly 102, and then the lower side as the combustion proceeds. This is because it burns more.

The crude analyzer 154 may be configured to correspond to the corresponding output based on the output of the nuclear fuel assembly 102 in the last operation cycle among the outputs of each operation cycle of the reactor 100 provided from the output measuring unit 152. Model the credential information that is expected to exist in.

In this case, the crude information may refer to information on the amount of the crude oil generated in accordance with one operation cycle of the fuel assembly 102 and material distribution information in the clad, and such material distribution information may be used to determine boron concentration values in the clad. It may mean, but is not limited thereto.

In addition, the clad analysis unit 154 performs the fuel modeling as described above, the fuel assembly 102 as shown in Figure 3 showing the shape (cx) of the fuel (Axial shape of crud) on the fuel assembly 102. It is assumed that a large amount of the crude shape function occurs in the axial upper side of the c), and the amount of crude in the reactor 100 is estimated from the assumed crude generation shape. In addition, by using the axial output distribution signal, which is the output of the fuel assembly 102, the model information is predicted by predicting the number density of boron in crud, which is one of material distribution information in the clad.

)에 대해서는 아래의 수학식 2에서와 같이 예측할 수 있다.At this time, the crude analysis unit 154 concentration of boron, which is one of the material distribution information in the crude (

) Can be predicted as in Equation 2 below.

In Equation 2, n represents a burnup step, and i represents an XS update index.

)상 핵연료 집합체(102)에 대한 각 연소 시점에서의 축방향 출력 분포 값과 실제 측정된 축방향 출력 분포 신호(

)상 핵연료 집합체(102)에 대한 각 연소 시점에서의 축방향 출력 분포 값을 비교한다.That is, the clad analysis unit 154 predicts the concentration of boron in the clad through Equation 2 above, for example, a basic axial output distribution signal in an environment without a creed (

The axial power distribution value and the actual measured axial power distribution signal at each combustion time point for the phase fuel assembly 102

The axial power distribution values at each combustion time point for the phase fuel assembly 102 are compared.

)상 핵연료 집합체(102)에 대한 각 연소 시점에서의 축방향 출력 분포 값이 실제 측정된 축방향 출력 분포 신호(

)상 핵연료 집합체(102)에 대한 각 연소 시점에서의 축방향 출력 분포 값에 최대한 수렴하도록 하는 크러드의 양과 보론의 농도를 예측한다.Then, the crude analysis unit 154 is a basic axial output distribution signal (

The axial power distribution signal at which the axial power distribution at each combustion time point for the phase fuel assembly 102 is actually measured.

The amount of the clad and the concentration of boron are predicted to maximize convergence to the axial power distribution value at each combustion time point for the phase fuel assembly 102.

In this case, when the axial output distribution signal is generated using the predicted amount of the crude and the concentration of boron, as shown in FIG. 2, modeling can be performed similarly to the actual measured axial output distribution signal.

The operating condition setting unit 156 predicts the material distribution information in the reactor 100 using the crude information modeled by the crude analyzer 154 and based on the predicted material distribution information, the reactor of the next operation cycle. The operation condition of 100 is set.

In this case, the material distribution in the reactor refers to a material distribution in the reactor 100 that has been changed since the fuel assembly 102 was burned in the reactor 100 in a previous operation cycle. It may refer to the amount of the crude generated in the reactor 100 after combustion and the concentration value of boron contained in the crude. In addition, the operating condition may mean a condition for operating the reactor 100 on which the nuclear fuel assembly 102 is mounted, and the reactor operating condition may be a dose of boron, a temperature of water, and the like in the reactor 100.

That is, the driving condition setting unit 156 may be configured to calculate the amount of boron to be administered to the reactor 100 in the next driving cycle based on the amount of the bored and the concentration value of boron in the crad predicted by the modeling in the previous driving cycle. You can set the operating conditions such as adjusting the temperature appropriately or adjusting the water temperature.

Figure 4 shows the operation control flow in the nuclear reactor analysis device according to an embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

The clad analysis device 150 measures the output of the reactor 100 generated by the combustion of the fuel assembly 102 for each driving cycle (S400). In this case, the output of the reactor may be, for example, an axial output distribution signal (ASI) as shown in FIG. 2.

Subsequently, the clad analysis apparatus 150 is configured to correspond to the corresponding output based on the output of the nuclear fuel assembly 102 in the previous operation cycle among the outputs of each operation cycle of the reactor 100 provided from the output measuring unit 152. Modeling the crude information expected to exist in the 100 (S402).

In this case, the crude information may refer to information on the amount of the crude oil generated in accordance with one operation cycle of the fuel assembly 102 and material distribution information in the clad, and such material distribution information may be used to determine boron concentration values in the clad. Can mean.

In other words, the clad analysis device 150 performs the fuel information modeling as described above, the fuel assembly (Axial shape of crud) as shown in FIG. Assuming that a relatively large amount of crude shape function occurs in the axial upper side of 102, the amount of crude in reactor 100 is estimated from the assumed crude generation shape. In addition, by using the axial output distribution signal, which is the output of the fuel assembly 102, the model information is predicted by predicting the number density of boron in crud, which is one of material distribution information in the clad.

Subsequently, the clad analysis apparatus 150 predicts material distribution information in the reactor 100 after the last operation cycle is completed by using the clad information modeled based on the output of the fuel assembly, and based on the predicted material distribution information. By setting the operating conditions of the reactor 100 of the next operation cycle (S404).

In this case, the material distribution in the reactor refers to a material distribution in the reactor 100 that has been changed since the fuel assembly 102 was burned in the reactor 100 in a previous operation cycle. It may refer to the amount of the crude generated in the reactor 100 after combustion and the concentration value of boron contained in the crude. In addition, the operating condition may mean a condition for operating the reactor 100 on which the nuclear fuel assembly 102 is mounted, and the reactor operating condition may be a dose of boron, a temperature of water, and the like in the reactor 100.

As described above, according to one embodiment of the invention, in the reactor reactor analysis, modeling the reactor nuclear reactor information based on the output of the reactor in accordance with the combustion of the fuel assembly in the operation cycle immediately before the operation of the reactor, The operating conditions of the next operating cycle of the reactor can be set based on the modeled clad information to increase the reactor operating efficiency.

Combinations of the steps of each flowchart attached to the present invention may be performed by computer program instructions. These computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer or other programmable data processing equipment such that the instructions performed through the processor of the computer or other programmable data processing equipment are described in each step of the flowchart. It will create a means to perform them. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in each step of the flowchart. Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for executing the functions described in each step of the flowchart.

In addition, each step may represent a module, segment or portion of code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative embodiments, the functions noted in the steps may occur out of order. For example, the two steps shown in succession may in fact be performed substantially simultaneously or the steps may sometimes be performed in the reverse order, depending on the function in question.

Meanwhile, in the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the invention should be determined by the claims rather than by the described embodiments.

150: crude analysis device 152: output measurement unit
154: crude analysis unit 156: operating condition setting unit

Claims (8)

An output measuring unit for measuring the output of the nuclear fuel assembly at each operation cycle of the reactor;
A crude analyzer for analyzing the nuclear reactor nuclear reactor information on the basis of the output of the fuel assembly in the previous operation cycle for each operation cycle;
An operation condition setting unit configured to set an operation condition of the nuclear reactor in a next operation period for the fuel assembly using the crude information;
Nuclear reactor analysis device. The method of claim 1,
The output of the fuel assembly is,
Axial output distribution signal (ASI),
The crude analysis unit,
In analyzing the crude information, the amount of crude generated in the reactor and the concentration of boron contained in the crude based on the axial output distribution signal
Nuclear reactor analysis device. The method of claim 2,
The crude analysis unit,
Generate a basic axial output distribution signal in an environment without the clad, and the axial output distribution value at each combustion point for the fuel assembly on the basic axial output distribution signal is the respective axial output distribution signal To predict the amount of bored and the concentration of boron to maximize convergence to the axial power distribution at
Nuclear reactor analysis device. The method of claim 3, wherein
The driving condition setting unit,
Setting operating conditions of the reactor of the next operation cycle based on the predicted amount of the crude in the reactor and the concentration value of boron;
Nuclear reactor analysis device. Measuring the output of the nuclear fuel assembly at each operation cycle of the reactor,
Analyzing the in-core reactor information based on the output of the fuel assembly in a previous operation cycle for each operation cycle;
Setting operating conditions of the reactor in a next operation cycle for the fuel assembly using the crude information;
Reactor Crude Analysis Method. The method of claim 4, wherein
The output of the fuel assembly is,
Axial output distribution signal (ASI),
The analyzing step,
Estimating the amount of crude generated in the reactor and the concentration of boron in the crude based on the axial output distribution signal
Reactor Crude Analysis Method. The method of claim 6,
The predicting step,
Generating a basic axial output distribution signal in an environment without said clad;
The amount of crude such that the axial output distribution value at each combustion point for the fuel assembly on the basic axial output distribution signal converges to the axial output distribution value at each combustion point on the axial output distribution signal as much as possible; Predicting the concentration of boron
Reactor Crude Analysis Method. The method of claim 7, wherein
The setting of the driving condition may include:
Setting operating conditions of the reactor of the next operation period based on the predicted amount of the crude in the reactor and the concentration value of boron;
Reactor Crude Analysis Method.

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