KR20230054213A - System and method for predicting total radiation leakage due to coolant leakage accident during chemical decontamination process - Google Patents

Abstract

Disclosed is a system for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process. The system for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process according to one aspect of the present invention is a system for predicting the amount of radioactivity leaked to the outside due to a coolant leakage accident occurring during a chemical decontamination process for dismantling a nuclear power plant and comprises: a first input unit for receiving oxide layer removal rate information obtained by performing a chemical decontamination process on a specific contaminated specimen selected from a nuclear power plant; a second input unit for receiving basic information comprising the total amount of coolant circulating along a system subject to chemical decontamination in the nuclear power plant and the total amount of radioactivity at a first point in time when the chemical decontamination process begins; a third input unit for receiving information on the amount of leaked coolant at a second time when a coolant leak accident occurs; and a prediction unit for predicting the amount of leaked radioactivity leaked to the outside at the second time by comprehensively considering the oxide layer removal rate information, basic information, and leaked coolant amount information.

Description

System and method for predicting total radiation leakage due to coolant leakage accident during chemical decontamination process}

The present invention relates to a system and method for predicting total radioactivity leaked due to a coolant leak accident, and more particularly, to a system and method for predicting total radioactivity leaked due to a coolant leak accident occurring during a chemical decontamination process.

System decontamination technology is a technology that uses chemical decontamination agents to remove radioactive contaminants adhered to the inner surface of pipes or equipment in order to reduce the dose rate throughout the system by making the most of the existing power plant operation system immediately after the permanent shutdown of a nuclear power plant. It is an operation method that removes the contaminated oxide film and part of the base metal in the reactor coolant system by operating unit facilities with chemicals.

For example, Kori Unit 1, the first pressurized water reactor built in Korea, was permanently shut down on June 19, 2017. Systemic decontamination is planned, and in this regard, systemic decontamination using chemical decontamination can be performed.

Meanwhile, in relation to systemic decontamination, there is a possibility that cooling water leaks out in the process of circulating the decontamination agent through a pump. In this case, radioactivity may be leaked to the outside together with the leaked coolant. In order to quickly deal with such a leak accident, it is necessary to accurately predict and respond to the amount of leaked radioactivity.

The present invention is to solve the above problems, and an object of the present invention is to provide a system and method capable of rapidly and accurately predicting the total radioactivity leaked due to a coolant leakage accident occurring during the chemical decontamination process.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

According to one aspect of the present invention, as a system for predicting the amount of radioactivity leaked to the outside due to a coolant leakage accident occurring during the chemical decontamination process for dismantling a nuclear power plant, the chemical decontamination for a specific contaminated specimen selected from the nuclear power plant a first input unit into which oxide layer removal rate information obtained by performing the process is input; A second input unit into which basic information including a total amount of coolant circulated along the system to be subjected to chemical decontamination and a total amount of radioactivity at a first time point when the chemical decontamination process starts in the nuclear power plant is input; a third input unit to which information on an amount of leaked coolant at a second time point when the coolant leakage accident occurs is input; and a prediction unit that comprehensively considers the oxide layer removal rate information, the basic information, and the leakage coolant amount information to predict the amount of leaked radioactivity leaked to the outside at the second time point; including coolant leakage during the chemical decontamination process. A system for predicting total radiation released by an accident is provided.

At this time, the amount of leaked radioactivity can be predicted by the following equation.

[mathematical expression]

At this time, the system includes a reactor coolant system including a reactor pressure vessel, a steam generator, and a pressurizer, and a residual heat removal system, and the coolant may be circulated by a reactor coolant pump and a residual heat removal pump.

In this case, the chemical decontamination process may be performed by repeating a unit cycle a plurality of times in which an oxidation process for a first time and a reduction process for a second time are set as one set.

At this time, the first input unit displays a plurality of points coordinated according to the following equation on a two-dimensional plane, and the prediction unit, from a graph formed by connecting the plurality of points, the oxide layer removal rate information at the second time point can be estimated.

[mathematical expression]

In this case, the oxide layer removal rate information may be calculated by comparing the dose rate or surface radioactivity measured at a specific time point with the dose rate or surface radioactivity value measured at a first time point.

At this time, the oxide layer removal rate information may be calculated by considering the dose rate and the surface radioactivity together.

According to another aspect of the present invention, as a method for predicting the amount of radioactivity leaked to the outside due to a coolant leakage accident occurring during the chemical decontamination process for dismantling a nuclear power plant, the chemical decontamination for a specific contaminated specimen selected from the nuclear power plant Obtaining oxide layer removal rate information by performing a process; Acquiring basic information including a total amount of coolant circulated along a system subject to chemical decontamination in the nuclear power plant and a total amount of radioactivity at a first point in time when the chemical decontamination process starts; obtaining information on the amount of leaked coolant at a second time point when the coolant leakage accident occurs; And predicting the amount of radioactivity leaked according to the following equation; a method for predicting the total radioactivity leaked due to a coolant leakage accident occurring during the chemical decontamination process is provided.

[mathematical expression]

In this case, the chemical decontamination process may be performed by repeating a unit cycle a plurality of times in which an oxidation process for a first time and a reduction process for a second time are set as one set.

At this time, in the step of predicting the amount of leaked radioactivity, a plurality of points coordinated according to the following equation are displayed on a two-dimensional plane, and the oxide layer removal rate at the second time point is obtained from a graph formed by connecting the plurality of points. information can be inferred.

[mathematical expression]

According to the configuration described above, the system for predicting the total radioactivity leaked due to the coolant leakage accident occurring during the chemical decontamination process according to the embodiment of the present invention can quickly and accurately predict the amount of radioactivity leaked with only a small amount of calculation.

Through this, the system for predicting total radioactivity leaked due to a coolant leak accident occurring during the chemical decontamination process according to an embodiment of the present invention can quickly provide leak information so as to accurately determine the scale of damage caused by the leak accident.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a diagram schematically showing that a chemical decontamination process is performed by connecting a chemical decontamination facility to a nuclear power plant system.
2 is a block diagram showing a system for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process according to an embodiment of the present invention.
3 and 4 are tables for explaining a process of obtaining information on an oxide layer removal rate by time by performing a chemical decontamination process on a specific contaminated specimen.
FIG. 5 is a graph showing a graph formed by connecting a plurality of coordinated points in relation to the oxide layer removal rate information by time of FIGS. 3 and 4 .
6 is a flowchart illustrating a method for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In order to clearly describe the present invention, parts irrelevant to the description are omitted in the drawings, and the same reference numerals are assigned to the same or similar components throughout the specification.

Words and terms used in this specification and claims are not construed as limited in their ordinary or dictionary meanings, but in accordance with the principle that the inventors can define terms and concepts in order to best describe their inventions. It should be interpreted as a meaning and concept that corresponds to the technical idea.

1 is a diagram schematically showing that a chemical decontamination process is performed by connecting a chemical decontamination facility to a nuclear power plant system. 2 is a block diagram showing a system for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process according to an embodiment of the present invention. 3 and 4 are tables for explaining a process of obtaining information on an oxide layer removal rate by time by performing a chemical decontamination process on a specific contaminated specimen. FIG. 5 is a graph showing a graph formed by connecting a plurality of coordinated points in relation to the oxide layer removal rate information by time of FIGS. 3 and 4 .

The system for predicting total radiation (100, hereinafter referred to as 'total radiation prediction system') leaked due to a coolant leakage accident occurring during the chemical decontamination process according to an embodiment of the present invention is a chemical decontamination process performed prior to the dismantling of a nuclear power plant. It is a system for quickly predicting the amount of radioactivity leaked to the outside by the leaked coolant when an unexpected coolant leakage accident occurs. Through this, the person in charge of accident handling related to the chemical decontamination process can quickly and accurately grasp the scale of damage, so that they can respond to leakage accidents more effectively.

In relation to this, the chemical decontamination process to which the total radioactivity prediction system 100 according to an embodiment of the present invention is applied includes, for example, a reactor coolant system 210 and a residual heat removal system 220, as shown in FIG. It can be achieved by circulating a coolant containing a chemical decontamination agent with respect to the system 200. In this case, the reactor coolant system 210 may include a reactor pressure vessel 212, a steam generator 214, a pressurizer 216, and a reactor coolant pump 218, and the residual heat removal system 220 may include a residual heat removal pump. (228) and a residual heat removal heat exchanger (222). And, as shown in the drawing, the chemical decontamination facility 230 may be connected to the residual heat removal system 220 to supply the chemical decontamination agent, and the coolant containing the chemical decontamination agent is a reactor coolant pump 218 and a residual heat removal pump ( 228) can be used to circulate within the system and remove radioactive contaminants adhered to the inside of pipes.

At this time, the chemical decontamination process may be largely composed of an oxidation process and a reduction process. For example, in the chemical decontamination process, an oxidation process may be performed first for a first time (eg, 6 hours), and then a reduction process may be performed for a second time (eg, 10 hours). In addition, the unit cycle (for example, for a total of 16 hours) including the oxidation process and the reduction process as one set may be repeatedly performed a plurality of times (eg, three times).

And, the chemical decontamination agent used in the oxidation process may be, for example, a substance including 200 ppm of Permanganic acid, 2.5 mM of Nitric acid, 200 ppm of permanganic acid and 2.5 mM of nitric acid, and the chemical decontamination agent used in the chemical process is oxalic acid. 2000 ppm and 2000 ppm oxalic acid.

However, the flow of cooling water shown in FIG. 1 and the chemical decontamination process described above are only examples, and the example of the chemical decontamination process to which the total radioactivity prediction system according to an embodiment of the present invention is applied is not limited thereto. .

Hereinafter, the main configuration of the total activity prediction system 100 according to an embodiment of the present invention will be described with reference to the drawings.

2, the total radioactivity prediction system 100 according to an embodiment of the present invention includes a first input unit 10, a second input unit 20, a third input unit 30 and a prediction unit 50. can do.

At this time, the total activity prediction system 100 according to an embodiment of the present invention may be implemented in the form of hardware or software, or may be implemented in the form of a combination of hardware and software. Preferably, the first input unit 10 to the third input unit 30 are implemented as a memory storing predetermined data, and the prediction unit 50 may be implemented as a microprocessor, but the present invention is not limited thereto. .

First, the total radioactivity prediction system 100 according to an embodiment of the present invention may include a first input unit 10 into which oxide layer removal rate information k is input.

At this time, the oxide layer removal rate information (k) input to the first input unit 10 may mean information on how much the oxide layer, which contains radioactive contaminants and is adhered to pipes, etc., is removed compared to before chemical decontamination, For example, as shown in FIG. 5 , time-dependent oxide layer removal rate information, which is data on how the oxide layer removal rate changes over time, may be included. In this case, the information on the removal rate of the oxide layer by time (k) may be data related to how the oxide layer is removed according to the progress of the process when an actual chemical decontamination process is performed. As such, the oxide layer removal rate information (k) may be information related to an expected decontamination effect when a predetermined chemical decontamination process is performed for a nuclear power plant.

In one embodiment of the present invention, the oxide layer removal rate information k is pre-experimental data obtained before the actual chemical decontamination process is performed, and is input to the first input unit 10 after being obtained in advance before the chemical decontamination process is performed. It can be.

That is, the oxide layer removal rate information (k) is obtained by circulating cooling water (including chemical decontamination agent) for a specific contaminated specimen selected from an actual nuclear power plant under the same experimental conditions (eg, cooling water circulation cycle, etc.) as in the actual chemical decontamination process, At the same time, it may be obtained by measuring the degree of removal of the oxide layer through measurement equipment, and then input to the first input unit 10 .

As a specific example, referring to FIG. 3 , oxide layer removal rate information may be obtained by measuring a dose rate related to a specific contaminated specimen under test. For example, as shown in the figure, the dose rate (a) at the first time point (t1), which is the point at which chemical decontamination begins, is measured, and the dose rate (a) is repeated every time each cycle constituting the chemical decontamination process is completed. can measure

In addition, various information can be additionally derived from the measured dose rate (a) information and used as oxide layer removal rate information. For example, as shown in FIG. 3, the removed dose rate (b, dose rate difference) is derived through the difference between the measured dose rates, or the previous dose rate (a, for example, the dose rate after the first cycle is 235 ) compared to the remaining dose rate after one cycle (in this case, the dose rate after the second cycle is 57) to derive the cycle decontamination factor (c, Decontamination Factor, in this case 4.12), or the previous dose rate (a, for example 235) compared to the removed dose rate (b, in this case 178) to derive the cycle removal rate (d, 0.75), or the dose rate at the first time point (t1) (a, 650) versus the dose rate remaining after each cycle is completed (e.g. For example, after the second cycle has progressed, the total decontamination factor (e, 11.40 in this case) is derived by comparing the dose rate (57), or the cumulative value of the removed dose rate compared to the dose rate (a, 650) at the first time point (t1) (650-57 in this case), the total oxide layer removal rate (f, 0.91), etc. can be derived. At this time, the decontamination factor (c or e) and the removal rate (d or f) are in the relationship of Equation 1 below.

[Equation 1]

As another example, referring to FIG. 4 , oxide layer removal rate information may be obtained by measuring surface activity related to a specific contaminated specimen under test. For example, as shown in the figure, surface radioactivity (a′) is measured at the first time point (t1), which is the time point at which chemical decontamination begins, and is repeated every time an individual cycle constituting the chemical decontamination process is completed. a') can be measured.

In this case, similar to the dose rate (a), information such as decontamination factors (c', e') or removal rates (d', f') can be derived using the measured surface activity (a'). The derivation method is the same as in the example examined in dose rate (a), so it will be omitted to avoid redundant explanation.

On the other hand, the oxide layer removal rate information k is stored in the first input unit 10 and then transferred to the prediction unit 50 to be described later and used to predict the amount of leaked radioactivity R2. At this time, since the oxide layer removal rate information (k) is obtained by performing the same chemical decontamination process on the contaminated specimens that constituted part of the actual nuclear power plant as described above, the prediction unit 50 predicts that the actual chemical decontamination process will be performed later. Similarly, the total amount of radioactivity released can be predicted on the premise that the oxide layer will be removed. This will be described in more detail through a description related to the prediction unit 50.

Next, the total activity prediction system 100 according to an embodiment of the present invention may include a second input unit 20 into which basic information related to a nuclear power plant where chemical decontamination is to be performed is input.

As an illustrative example, the basic information may include information on the total amount of coolant circulated along a system subject to chemical decontamination in a nuclear power plant. This information on the total amount of coolant may have a value in units of mass, and may be used as reference data of the mass of the leaked coolant when the prediction unit 50 predicts the total amount of leaked radiation, which will also be described later.

As another example, the basic information may include information on the total amount of radioactivity measured for the nuclear power plant at the first time point t1 when the chemical decontamination process starts. At this time, the total amount of radioactivity information may mean total amount of radioactivity emitted from all radioactive contaminants adhered to pipes, etc. in a state in which chemical decontamination is not performed, and like the total amount of coolant information, the prediction unit 50 It can be used as reference data when estimating the total amount of radioactivity leaked.

The total amount of radioactivity information may be measured using known measuring equipment at the first time point (t1), which is the time point at which chemical decontamination starts or earlier, but, unlike the first time point (t1), in advance It may be obtained through calculation considering the half-life of radioactive material from the measured total radioactive amount information. For example, when it is not easy to measure the total amount of radiation at the first time point t1, the total amount of radiation information may be obtained through calculation.

On the other hand, the example of the basic information is not limited to the above example, and in addition to this, any kind of basic information can be input to the second input unit 20 as long as it is information related to a nuclear power plant and can be used to predict the amount of radioactivity leaked. can

Next, the total activity prediction system 100 according to an embodiment of the present invention may include a third input unit 30 to which information on the amount of leaked coolant at the second time point t2 when the coolant leakage accident occurs is input. there is.

In this case, the leaked coolant amount information may mean the total mass or volume of the coolant leaked to the outside of the nuclear power plant system through which the coolant is circulated when an unexpected coolant leak accident occurs due to some cause.

Unlike the basic information input at the first point in time t1, when chemical decontamination begins, the information on the amount of leaked coolant is rapidly obtained through separate measuring equipment at the time of leakage accident (second time point t2). After that, it can be input to the third input unit 30 . That is, the information on the amount of leaked coolant is a variable variable that can have a variable value according to a measurement time point, and may have a different nature from basic information having a fixed value for a specific nuclear power plant.

Meanwhile, the information on the amount of leaked coolant may have, for example, a mass unit value, and may be directly measured through special measuring equipment installed at a plurality of points where coolant leakage is expected, or calculated from this after measuring the volume of the leaked coolant. may be derived.

Total radioactivity prediction system 100 according to an embodiment of the present invention may include a prediction unit 50 for predicting the amount of leaked radioactivity R2 leaked to the outside at the second time point.

At this time, the prediction unit 50 may derive the amount of leaked radioactivity R2 based on the information input to the above-described first input unit 10 to the third input unit 30 as shown in FIG. 2 . That is, the prediction unit 50 comprehensively considers the oxide layer removal rate information (k) obtained from a specific contaminated specimen, basic information related to the nuclear power plant, and information on the amount of leaked coolant (W2) at the second time point (t2) to externally The amount of leaked radioactivity (R2) can be predicted.

As a specific example, the amount of external leakage radiation R2 at the second time point t2 when the leak accident occurred can be predicted by Equation 2 below.

[Equation 2]

Looking at the meaning of Equation 2, the prediction unit 50 indicates that all of the radioactivity contained in the oxide layer separated from the pipe or the like by chemical decontamination is evenly distributed in the circulating coolant, and therefore, due to a leak accident When the coolant leaks to the outside, the total amount of radioactivity leaked to the outside at the second time point is predicted on the assumption that leaked radioactivity is generated in proportion to the amount (mass or volume) of the leaked coolant.

At this time, in Equation 2, information on the total amount of radiation (R1) and the total amount of circulated coolant (W1) at the first time point may be retrieved from basic information input to the second input unit 20. In addition, information on the amount of leaked coolant W2 at the second time point t2 may be retrieved from the third input unit 30 .

Meanwhile, the oxide layer removal rate information k at the second time point t2 in Equation 2 can be read from the first input unit 10 .

As a specific example related to this, the oxide layer removal rate information k at the second time point t2 is stored in the first input unit 10 in the form of a lookup table according to time, When the user inputs the time data at the time of the accident (the second time point t2), the corresponding oxide layer removal rate information (k) may be output from the lookup table and transmitted to the prediction unit 50.

As another example, as shown in FIG. 5 , the first input unit 10 inputs a plurality of points coordinated according to Equation 3 below on a two-dimensional plane in which time is the X axis and the oxide layer removal rate is the Y axis. After displaying, the oxide layer removal rate information (k) may be estimated using this.

[Equation 3]

Specifically, when the chemical decontamination process includes n number of cycles, on the coordinate plane (the first cycle completion time, the total oxide layer removal rate obtained at the first cycle completion time), (the second cycle completion time, the second cycle Total oxide layer removal rate obtained at the time of completion), ?? A total of n points including (the time point at which the nth cycle is completed and the total oxide layer removal rate obtained at the time point at which the nth cycle is completed) are displayed.

When this is applied to the examples of FIGS. 3 and 4, three points including (16 hours, 0.63 or 0.66), (32 hours, 0.91 or 0.93) and (48 hours, 0.99) are located on the coordinate plane as shown in FIG. will be displayed

Thereafter, the prediction unit 50 may form a broken line graph having various slopes for each section as shown in FIG. 5 by connecting adjacent points among a plurality of points disposed discontinuously on the coordinate plane. The prediction unit 50 may estimate the oxide layer removal rate information at the second point in time t2 by checking the oxide layer removal rate value corresponding to the value at the specific second point in time t2 from the broken line graph.

In this way, the total radioactivity prediction system 100 according to an embodiment of the present invention easily uses only a limited number of data (eg, oxide layer removal rate information at the time when each cycle is completed) by using the coordinated information as described above. It is possible to secure the oxide layer removal rate value corresponding to the entire time.

Referring back to FIG. 5, the prediction unit 50 constructs the above-described broken line graph using any one of the dose rate (a) and the surface radioactivity (a') in deriving the oxide layer removal rate information (k). can In this case, the prediction unit 50 may estimate the oxide layer removal rate information (k) by alternatively using one of the data expected to have higher accuracy among the dose rate (a) and the surface radioactivity (a').

Alternatively, the prediction unit 50 may estimate the oxide layer removal rate information (k) by considering both the dose rate (a) and the surface radioactivity (a'). For example, as shown in FIG. 5, the prediction unit 50 forms a separate graph located at the same distance (L) from a line graph formed from the values of the dose rate (a) and the surface radioactivity (a') to form an oxide layer Removal rate information k may be calculated. In this case, since the oxide layer removal rate information (k) is calculated using various data comprehensively, there is an advantage in that more accurate data can be secured.

Meanwhile, the prediction of the total radioactivity amount using Equation 3 described above is only an example in which the prediction unit 50 predicts the total amount of radioactivity. information can be derived.

In one embodiment of the present invention, each of the above-described components may be combined with each other to be implemented as one, or as shown in FIG. 2, each component may be implemented separately. For example, although the first input unit 10 to the third input unit 30 are shown as being separated independently from each other in the drawing, the first input unit 10 to the third input unit 30 are performed by a single input unit. It should be noted that it may refer to functions separately.

6 is a flowchart illustrating a method for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process according to an embodiment of the present invention.

On the other hand, a method for predicting total radioactivity leaked due to a coolant leakage accident occurring during the chemical decontamination process according to an embodiment of the present invention without a specific type of system such as the total radioactivity prediction system 100 described above (hereinafter, 'total radioactivity prediction Method'), the total amount of radioactivity leaked (W2) can be easily predicted. That is, the prediction principle inherent in the above-described total radioactivity prediction system 100 may be implemented manually by specific personnel or through other devices. Hereinafter, a total radioactivity prediction method according to an embodiment of the present invention will be described.

Specifically, referring to FIG. 6, the method for predicting total radioactivity according to an embodiment of the present invention includes the step of obtaining oxide layer removal rate information by performing a chemical decontamination process (S10), along the system to be subjected to chemical decontamination among nuclear power plants. Acquiring basic information including the total amount of circulating coolant (W1) and the total amount of radioactivity (R1) at the first time point (t1) at which the chemical decontamination process starts (S20), the second time point when the coolant leakage accident occurs Obtaining information on the amount of leaked coolant of (t2) (S30) and estimating the amount of leaked radioactivity (S40) may be included.

At this time, the work performed in each step (S10 to S40) may be the same as or similar to the work performed by each component of the total activity prediction system 100 described above.

That is, in the step of obtaining oxide layer removal rate information (S10), as described above, it is possible to obtain oxide layer removal rate information by performing a process simulating an actual chemical decontamination process in advance for a specific contaminated specimen selected from a nuclear power plant. In addition, the basic information acquired in the step of acquiring basic information (S20) may be various information related to the nuclear power plant as described above, and in the step of acquiring information on the amount of leaked coolant at the second point in time (t2) (S30) Also, the mass or volume of the coolant leaked to the outside of the system due to the coolant leakage accident can be measured.

In addition, in the step of predicting the amount of leaked radioactivity (S40), the total amount of radioactivity leaked (R2) is predicted by collecting and comprehensively considering information such as the oxide layer removal rate (k), basic information, and the amount of leaked coolant (W2). For example, it can be predicted using Equation 2 described above.

As such, the detailed implementation process of the total activity prediction method according to an embodiment of the present invention is the same as or similar to the process used in the total activity prediction system 100 according to an embodiment of the present invention, so that no further duplication is required for convenience of explanation. description is omitted.

As described above, the total radioactivity prediction system 100 and method according to an embodiment of the present invention can accurately predict the amount of leaked radioactivity R2 with only a relatively small amount of calculation. In particular, the total radioactivity prediction system 100 according to an embodiment of the present invention receives information from the first input unit 10 to the third input unit 30 and at the same time sends the leaked radioactivity to the person in charge of the accident management of the coolant leakage accident in real time. Quantity (R2) information can be provided.

Through this, the person in charge of handling the accident can quickly and accurately grasp the scale of the damage caused by the leakage accident, and also organize the input manpower to be put into the field by considering the exact amount of radiation coverage.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited by the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention will, within the scope of the same spirit, of the components Other embodiments can be easily suggested by addition, change, deletion, addition, etc., but it will also be said that this is also within the scope of the present invention.

10: first input unit 20: second input unit
30: third input unit 50: prediction unit
100: total radiation prediction system

Claims (10)

A system for predicting the amount of radioactivity leaked to the outside due to a coolant leakage accident that occurred during the chemical decontamination process for dismantling a nuclear power plant,
a first input unit to which oxide layer removal rate information obtained by performing the chemical decontamination process on a specific contaminated specimen selected from the nuclear power plant is input;
A second input unit into which basic information including a total amount of coolant circulated along the system to be subjected to chemical decontamination and a total amount of radioactivity at a first time point when the chemical decontamination process starts in the nuclear power plant is input;
a third input unit to which information on an amount of leaked coolant at a second time point when the coolant leakage accident occurs is input; and
A prediction unit for predicting the amount of leaked radioactivity leaked to the outside at the second time point by comprehensively considering the oxide layer removal rate information, the basic information, and the leaked coolant amount information; including a coolant leak accident occurring during the chemical decontamination process The system for predicting total radiation leaked by According to claim 1,
The total radioactivity prediction system leaked by the coolant leak accident occurring during the chemical decontamination process, wherein the amount of leaked radioactivity is predicted by the following equation.
[mathematical expression]

According to claim 1,
The system includes a reactor coolant system and a residual heat removal system including a reactor pressure vessel, a steam generator, and a pressurizer,
The total radiation prediction system leaked by a coolant leak accident occurring during the chemical decontamination process, wherein the coolant is circulated by a reactor coolant pump and a residual heat removal pump. According to claim 1,
The chemical decontamination process is carried out by repeating a unit cycle of a set of an oxidation process for a first time and a reduction process for a second time, which is performed by repeating a plurality of times. Total Radiation Prediction System. According to claim 4,
The first input unit displays a plurality of coordinated points on a two-dimensional plane according to the following equation,
Wherein the prediction unit estimates the oxide layer removal rate information at the second point in time from a graph formed by connecting the plurality of points, the system for predicting total radioactivity leaked due to a coolant leakage accident occurring during a chemical decontamination process.
[mathematical expression]

According to claim 1,
The oxide layer removal rate information is calculated by comparing the dose rate or surface radioactivity measured at a specific time point with the dose rate or surface radioactivity value measured at the first time point, leaked due to a coolant leakage accident during the chemical decontamination process Total radioactivity prediction system. According to claim 6,
The oxidation layer removal rate information is calculated by considering the dose rate and the surface radioactivity together, the total radioactivity leaked by the coolant leakage accident occurring during the chemical decontamination process. As a method for predicting the amount of radioactivity leaked to the outside due to a coolant leakage accident that occurred during the chemical decontamination process for dismantling a nuclear power plant,
Obtaining oxide layer removal rate information by performing the chemical decontamination process on a specific contaminated specimen selected from the nuclear power plant;
Acquiring basic information including a total amount of coolant circulated along a system subject to chemical decontamination in the nuclear power plant and a total amount of radioactivity at a first point in time when the chemical decontamination process starts;
obtaining information on the amount of leaked coolant at a second time point when the coolant leakage accident occurs; and
A method for predicting the total radioactivity leaked by a coolant leak accident occurring during a chemical decontamination process, comprising: predicting the amount of radioactivity leaked according to the following equation.
[mathematical expression]

According to claim 8,
The chemical decontamination process is carried out by repeating a unit cycle of a set of an oxidation process for a first time and a reduction process for a second time, which is performed by repeating a plurality of times. Total radioactivity prediction method. According to claim 9,
In the step of predicting the amount of leaked radioactivity,
A plurality of points coordinated according to the following equation are displayed on a two-dimensional plane, and the oxidation layer removal rate information at the second time point is estimated from a graph formed by connecting the plurality of points, coolant leakage occurred during the chemical decontamination process A method for predicting the total radioactivity released by an accident.
[mathematical expression]

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