KR102021763B1 - Boron meter with inlet pipe - Google Patents

Abstract

The present invention relates to a boron concentration measurement device and, more specifically, to a boron concentration measurement device including an inlet pipe having a function for improving the state of the mixture of coolants in a nuclear reactor. The purpose of the present invention is to provide a boron concentration measurement device capable of optimizing performance by extending an inlet pipe, which makes a coolant for a nuclear reactor flow into a case, from a neutron source along the inner surface of the case longer than before. According to the present invention, since an inlet pipe is extended from a neutron source along the inner surface of a case longer than before, coolants in a nuclear reactor can be mixed smoothly in the center of a detector, and an improvement in the mixture state can increase the reliability of a measurement value measured by the detector.

Description

Boron concentration meter with inlet pipe {BORON METER WITH INLET PIPE}

The present invention relates to a boron concentration meter, and more particularly to a boron concentration meter having an inlet pipe (Inlet Pipe) having a function of improving the reactor coolant mixing state.

In nuclear power plants, natural boric acid water is added to the reactor coolant to control the long-term reactivity of the fuel. Since the criticality depends on the concentration of boric acid, it is very important for safe operation of nuclear power plants. In order to measure the boron concentration of the reactor coolant, nuclear power plants use a chemical analysis method and a neutron absorption method using boron meters.

The chemical analysis method is a chemical analysis method using a neutralization titration method by taking a sample of the coolant and measuring the concentration of boron in the reactor coolant, which has the advantage of having high accuracy, but cannot be continuously measured and radioactive waste. There is a problem that occurs.

The neutron absorption method using a boron meter (boron concentration meter) measures the concentration of boron in the reactor coolant by detecting the degree of reaction of boron in the reactor coolant according to the neutron emission from the neutron source. Although it is possible to measure by, and does not generate radioactive waste, there is a disadvantage that the accuracy is lower than the chemical analysis method.

The measurement of boron concentration using a conventional boron meter (boron concentration meter) has low reliability due to a large error compared to the chemical analysis method, so it cannot be used for nuclear power operation such as fuel loading, starting operation, and reactivity control. There is a problem that it is used only to identify the trend of concentration change.

1. Korea Registered Patent No. 10-1813362 (Announced Dec. 29, 2017) 2. Korean Patent Registration No. 10-1139619 (Announcement of April 17, 2012)

The present invention is to solve the above problems, boron concentration optimized for performance by forming an inlet pipe (Inlet Pipe) for allowing the reactor coolant to flow into the case to extend around the neutron source along the inner wall of the case than the conventional It is an object to provide a meter.

Boron concentration measuring apparatus equipped with an inlet pipe (Inlet Pipe) according to an embodiment of the present invention for achieving the above object is a vessel for detecting the boron contained in the reactor coolant is introduced and discharged, A sampler assembly incorporating Vessel, electronics for calculating the concentration of boron in the reactor coolant based on the boron detection value detected by the sampler assembly, and the vessel Vessel is formed in the inner space, the case into which the reactor coolant flows, is provided in the inner center of the case, the neutron source for emitting neutrons, the inside of the case, through the neutron emitted from the neutron source A plurality of detectors for detecting boron contained in the reactor coolant, the reactor coolant is introduced into the case Inlet pipe (Inlet Pipe) is formed to extend along the inner wall in the case and OutletPipe for discharging the reactor coolant introduced into the case.

In addition, the case is a cylindrical having a predetermined length, the neutron source and the plurality of detectors are formed to extend by a predetermined length in the longitudinal direction from the top of the case, the plurality of detectors are the inner wall of the case and the Circularly disposed at a predetermined interval between the outer surface of the neutron source, the inlet pipe (Inlet Pipe) is inserted in the longitudinal direction from the top of the case, is formed to extend along the inner wall of the case around the neutron source It is characterized by.

In addition, the length of the inlet pipe (Inlet Pipe) is formed to extend along the inner wall of the case around the neutron source is characterized in that 1/2 of the case circumference.

As described above, the present invention can have an effect that the mixing of the reactor coolant flow smoothly in the center of the detector by forming the inlet pipe extending along the inner wall of the case to the neutron source than the conventional one In addition, the mixed state may be improved to increase the reliability of the measured value measured at the detector.

1 is a perspective view of a boron concentration meter according to the present invention
2 is a perspective view of a vessel having a conventional inlet pipe
3 is a perspective view of a vessel having an inlet pipe according to the present invention;
4 is a perspective view of a vessel having an inlet pipe of another embodiment according to the present invention;
5 is a graph showing velocity vector results according to flow analysis
6 is a view showing a velocity distribution result according to the flow analysis
7 is a view showing the pressure distribution results according to the flow analysis
8 is a view showing the flow trajectory results according to the flow analysis
9 is a diagram of a flow velocity evaluation position around a detector;
10 is a plot of velocity output points around each detector.
11 is a graph showing the absolute deviation of the speed and the average speed for each point measured at the center of the measuring sensor
12 is a graph showing the absolute deviation of the speed and the average speed for each point measured at a position 50 mm from the center of the measuring sensor

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing the drawings, similar reference numerals are used for similar elements. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, a boron concentration meter having an inlet pipe having a function of improving a reactor coolant mixing state according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. The following description of the well-known matter is omitted or simplified to clarify the gist of the present invention.

1 is a perspective view of a boron concentration meter according to the present invention. 2 is a perspective view of a conventional vessel (Vessel). 3 is a perspective view of a vessel (Vessel) according to the present invention. 4 is a perspective view of a vessel having an inlet pipe of another embodiment according to the present invention.

Boron concentration meter (1) having an inlet pipe (Inlet Pipe) having a function of improving the reactor coolant mixing state according to the present invention is formed to extend the inlet pipe (Inlet Pipe) along the inner wall of the case around the neutron source than conventional This allows smooth mixing of the reactor coolant flow at the center of the detector. Accordingly, the mixed state can be improved and the reliability of the measured value measured at the detector can be increased by improving the mixed state.

1 to 4, the boron concentration meter 1 equipped with an inlet pipe having a function of improving the reactor coolant mixing state includes a sampler assembly 100 and electronics 200. It may include.

The sampler assembly 100 includes a reactor 110 in which reactor coolant is introduced and discharged, and has a vessel 110 for detecting boron contained in the reactor coolant, and at one side of the electronics 200. ) May be combined.

The vessel 110 may enter and exit the reactor coolant and detect boron contained in the introduced reactor coolant. The vessel 110 may include a case 111, a neutron source 112, a detector 113, an inlet pipe 114, and an outlet pipe 115.

The case 111 may have a cylindrical shape having a predetermined length, and a space may be formed therein to allow the reactor coolant to flow therein. A neutron source 112 may be provided at an inner center of the case 111, and a plurality of detectors 113 are disposed around the neutron source 112 between the inner wall of the case 111 and the neutron source 112. Can be.

In addition, a plurality of holes may be formed in the upper part of the case 111 so that the inlet pipe 114 and the outlet pipe 115 may be inserted therein.

The neutron source 112 may be formed to extend by a predetermined length in the longitudinal direction from the top of the case 111 to the inner center of the case 111, and to measure the distribution of neutrons varying with the boron concentration The distribution may be a source that emits neutrons of the same intensity.

The neutron source 112 can be made of a mixture of nuclei that cause α decay and (α, n) reactions, and the Am-Be neutron source 112 can be formed of (α, n) the reaction can release a constant neutron.

The detector 113 may be provided in plural in the case 111, and may be formed to extend by a predetermined length in the longitudinal direction from the top of the case 111. In addition, the detector 113 may be circularly disposed at a predetermined interval between the inner wall of the case 111 and the outer surface of the neutron source 112 around the neutron source 112 and may be emitted from the neutron source 112. Boron contained in the reactor coolant introduced into the inner space of the case 111 may be detected through the neutron.

The detector 113 may use a BF3 detector (counter), and may be composed of BF3 gas between 0.5 and 1 atmosphere in a tube formed of either aluminum or copper material.

In addition, the plurality of detectors 113 may include a plurality of detectors having a relatively high sensitivity and a plurality of detectors having a relatively low sensitivity within the range of the maximum boron detection value that may be included in the reactor coolant.

For example, the detector 113 may be selectively used according to a section classified by boron concentration by mixing two to four detectors having high sensitivity and four detectors having low sensitivity.

Here, the neutron source 112 and the detector 113 may both be formed to extend by a predetermined length in the longitudinal direction from the top of the case 111, the predetermined length of the neutron source 112 and the detector 113 is May differ from one another.

The inlet pipe 114 may be inserted into one of a plurality of holes formed in the upper portion of the case 111, and may introduce the reactor coolant into the inner space of the case 111. The inlet pipe 114 may be inserted at a predetermined length in the longitudinal direction from the top of the case 111, and may be formed to extend along the inner wall of the case 111 about the neutron source 112. have.

In addition, the length of the inlet pipe 114 formed to extend along the inner wall of the case 111 with respect to the neutron source 112 may be 1/2 of the circumference of the case 111.

The OutletPipe 115 may be inserted into one of a plurality of holes formed in the upper portion of the case 111, and discharge the reactor coolant introduced into the space of the case 111.

The electronics 200 may be provided on the side of the sampler assembly 100, and the boron contained in the reactor coolant based on the boron detection value detected by the sampler assembly 100. The concentration can be calculated.

2 is a perspective view of a vessel having a conventional inlet pipe. 3 is a perspective view of a vessel having an inlet pipe according to the present invention. 4 is a perspective view of a vessel having an inlet pipe of another embodiment according to the present invention.

Vessel having a conventional inlet pipe (hereinafter referred to as 'type A') and vessel having an inlet pipe according to the present invention (hereinafter referred to as 'B type') Flow analysis in the case of the mixed state of the reactor coolant according to the vessel (hereinafter referred to as 'C type') having the inlet pipe of another embodiment of the present invention. Compare through.

Herein, the vessel of the C type has a vessel having an inlet pipe formed to extend by a predetermined length with a slope of 5 degrees downward from the end of the inlet pipe 114 according to the present invention. Vessel.

The conditions of the flow analysis are as follows.

In the flow analysis, the inlet port is given an inlet flow rate of 8.0 gpm, and the outlet port is given an outlet pressure of 52.5 psig as the boundary condition.

According to the above conditions, the flow analysis results for the vessels of type A, type B and type C are as follows.

i) velocity vector

5 is a view showing a velocity vector results according to the flow analysis.

Referring to Figure 5, the result of the velocity vector according to the flow analysis can be confirmed that the behavior of the fluid is active in all the vessels (Vessel) of the A, B, C type.

ii) velocity distribution

6 is a diagram illustrating a velocity distribution result according to a flow analysis.

Referring to Figure 6, the results of the velocity distribution according to the flow analysis it can be seen that the A, B, C type vessels (vessels) all show a uniform flow distribution.

iii) pressure distribution

7 is a diagram illustrating a pressure distribution result according to a flow analysis.

Referring to Figure 7, the results of the pressure distribution according to the flow analysis it can be seen that the pressure decreases from the inlet to the outlet of all of the vessels (Vessel) of the A, B, C type.

iv) flow trajectory

8 is a view showing a flow trajectory result according to the flow analysis.

Referring to FIG. 8, as a result of the flow trajectory according to the flow analysis, type A and type B were smoothly mixed in the flow, and type C was confirmed that the mixing of the flow did not occur properly. In addition, in type A, the mixing of the flow is concentrated on one side of the lower side, and in the type B, it is determined that the mixing of the flow is uniform in the type B rather than the type A, because the mixing of the flow is concentrated in the upper center.

v) flow velocity analysis around the detector

The detector may be composed of two high sensitivity detectors and four low sensitivity detectors. The detector may be analyzed based on a high sensitivity detector having a short measuring sensor in the detector.

9 is a diagram of a flow velocity evaluation position around a detector. 10 is a plot of velocity output points around each detector.

9 to 10, the flow velocity evaluation position may be a 50 mm lower position from the center and the measuring sensor center of the detector, and a total of 12 points are selected for each of the two points on each side of each detector to obtain a velocity result of each point around the detector. You can print

The average speed is calculated by calculating the velocity and velocity distribution for each point on the sides of the detectors of the A, B and C vessels at the center of the measuring sensor.

[Point-to-point velocity measured at the center of the measuring sensor]

[Mean Speed by Type Measured at the Center of Measuring Sensor]

11 is a graph showing the absolute deviation of the speed and the average speed for each point measured at the center of the measurement sensor.

Referring to FIG. 11, as a result of obtaining the absolute deviations of the velocity and the average velocity for each point measured at the center of the measurement sensor, the deviation was large in the A type and C type vessels, and the B type vessels. ) Was the least.

The average speed is calculated by calculating the speed and speed distribution for each point on both sides of the detectors of type A, type B, and type C vessels 50mm below the center of the measuring sensor.

[Point-by-point velocity measured 50 mm below the center of the measuring sensor]

[Mean Speed by Type Measured 50mm from the Center of Measurement Sensor]

12 is a graph showing the absolute deviation of the speed and the average speed for each point measured at a position 50mm from the center of the measurement sensor.

Referring to FIG. 12, as a result of obtaining the absolute deviations of the velocity and the average velocity for each point measured at a position 50 mm below the center of the measuring sensor, the deviations in the A and C type vessels are similar to those shown in the center of the measuring sensor. Was found to be large, and was the lowest in the B type Vessel.

In summary, as a result of the flow analysis on the A, B, and C vessels, the flows of the A, B, and C vessels are all active in the vessel. From the velocity distribution and the pressure distribution, it can be seen that the flows of the A, B, and C vessels are similar.

However, from the flow trajectory results, it was confirmed that the type C mixing did not occur properly. In the type A and type B, the mixing of the flow was smooth, but in the type A, the mixing of the flow was concentrated on one side of the lower part. It can be judged that the mixing of is concentrated in the upper center so that the mixing state of the flow is uniform in the B type rather than the A type.

In addition, as a result of comparing the flow velocity around the detector at a position 50 mm from the center of the measuring sensor center and the measuring sensor of the detector, it can be seen that the flow velocity in the B-type vessel is evenly distributed.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. Of course, such changes will fall within the scope of the claims.

1: Boron concentration meter equipped with an inlet pipe to improve the mixing state of the reactor coolant
100: sampler assembly
110: Vessel
111: Case
112: neutron source
113: detector
114: Inlet Pipe
115: Outlet Pipe
200: Electronics

Claims (3)

A sampler assembly in which a reactor coolant is introduced and discharged, and a vessel including Vessel for detecting boron contained in the introduced reactor coolant is embedded;
Electronics for calculating the concentration of boron contained in the reactor coolant based on the boron detection value detected by the sampler assembly (Sampler Assembly); Including;
The vessel is
An internal space is formed, the case into which the reactor coolant flows,
A neutron source provided in the inner center of the case and emitting neutrons,
A plurality of detectors provided inside the case and detecting boron contained in the reactor coolant through neutrons emitted from the neutron source;
An inlet pipe flowing the reactor coolant into the case and extending along an inner wall of the case;
It includes an outlet pipe (outlet pipe) for discharging the reactor coolant introduced into the case,
The case is cylindrical having a predetermined length,
The neutron source and the plurality of detectors are formed to extend by a predetermined length in the longitudinal direction from the top of the case,
The plurality of detectors are circularly arranged at a predetermined interval between the inner wall of the case and the outer surface of the neutron source,
The inlet pipe is inserted in the longitudinal direction from the top of the case, the boron concentration with the inlet pipe (Inlet Pipe) characterized in that formed to extend along the inner wall of the case around the neutron source Measuring instrument. delete The method of claim 1,
The length of the inlet pipe (Inlet Pipe) is formed to extend along the inner wall of the case around the neutron source is a boron concentration meter having an inlet pipe (Inlet Pipe), characterized in that 1/2 of the case circumference .

Images