JPH1183767A - Density measurement device for specified element in fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of highly accurately and continuously measuring the density of the fine amount of Fe and Cu in the secondary system water supply of the pressurized water reactor of an atomic power plant without the need of labor and time. SOLUTION: The fine amount of Fe and Cu in the secondary system water supply is scavenged by the filter 13 of a flow cell 11 and it is detected by fluorescent X-ray analysis. Moreover, the plural flow cells 11 and 12 are provided, the filter 13 for scavenging the granular components of Fe and Cu is provided in one flow cell 11, the filter 14 for scavenging the ion components of Fe and Cu is provided in the other flow cell 12 and fluorescent X-ray detectors 21 and 22 are equipped in the respective flow cells 11 and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentration measuring device used for continuous measurement of the concentration of trace metal components such as iron and copper in secondary water of a pressurized water reactor at a nuclear power plant.

[0002]

2. Description of the Related Art A pressurized water light water reactor (PW) of a nuclear power plant
In R), from the viewpoint of maintaining the soundness of the steam generator, various measures have been studied and implemented to reduce the iron concentration in the secondary system feedwater. In addition, an advanced measurement technique that can accurately measure the concentration of a small amount of iron contained in the secondary system feedwater is required. Conventionally, this concentration measurement has been performed by a manual analysis method that requires a concentration operation and the like.

[0003]

However, the hand analysis method is
Pretreatment, such as concentration, was very troublesome due to the very small amount of iron in the secondary system feed water, and a single measurement required much time and labor. Therefore, it has been very difficult to continuously measure the concentration.

[0004] The present invention provides a concentration measuring apparatus capable of measuring the concentration of a specific element contained in a fluid with high accuracy without requiring much labor and time, even if the concentration is very small. Accordingly, it is an object to solve the above-described problems.

[0005]

The object of the present invention is to provide at least a first fluid passage in a fluid passage containing a specific element to be measured.
A second two flow cells are provided, the first flow cell is provided with a first filter for trapping the element component present in the fluid in the first form, and the second flow cell is provided with a first filter in the fluid. A second filter for collecting the elemental components present in a second form having a form different from the first form is provided, and each of the flow cells is irradiated with a radiation from a collected matter. The problem is solved by a device for measuring the concentration of a specific element in a fluid, characterized in that an X-ray fluorescence detector for detecting emitted X-ray fluorescence is provided.

[0006] The apparatus of the present invention is intended to measure a trace amount of a specific element contained in a fluid. That is, "fluid"
It may be a liquid or a gas. The liquid may be, for example, water, seawater, chemicals, oil, and the like. Further, the gas may be air, steam, organic gas, aerosol, or the like. "Specific elements" include iron,
It may be a metal element such as copper, zinc, chromium, nickel, and lead, and various other elements existing in the fluid, such as sulfur and chlorine. Further, as the `` form '' of the specific element in the fluid, for example, in addition to the form classified in the form of particles, ions, etc. It may be a form classified by the oxidation state of the metal element, or a combination of these forms.

[0007] In the above-mentioned apparatus, a specific element component in a fluid is collected by a filter of a flow cell and detected by X-ray fluorescence analysis. Even if the amount of the component is very small, the concentration can be measured with high accuracy.
In addition, it is possible to increase the frequency of measurement and to achieve continuous measurement without requiring time and labor for the measurement.

[0008] In addition, instead of collecting only one specific form of a specific element component, two or more forms of the specific element component are collected and used as a basis for measuring the concentration of the specific element component. Therefore, even if the specific element component contained in the fluid is extremely small, the concentration can be measured with extremely high accuracy.

In addition, it is possible to grasp the concentration for each form, and to grasp the cause of the concentration fluctuation in detail by grasping which form of the specific element varies in concentration. It is also possible to grasp and specify. For example, by measuring trace amounts of specific elements in the secondary system feed water of a nuclear power plant in multiple forms, it is possible to grasp and identify in detail the type of corrosion that is progressing in the secondary system. It is also possible.

In the above case, the form of the specific element component is as follows:
By collecting particulate and ionic components, it is possible to measure concentrations based on specific element components in both forms, and measure the concentration of trace specific element components with high accuracy. it can. Note that the second flow cell is connected to the first flow cell.
By interposing the specific element component in the form of particles and the specific element component in the form of ions, it is possible to properly separate and collect the specific element component in the form of ions and the specific element component in the form of ions.

Further, since the fluid introduction port of the flow passage is provided at a position higher than the first flow cell, the specific element component in the form of particles acting on its own weight acts on the first flow cell from the fluid introduction port. It can be smoothly fed into the flow cell without adhering and accumulating in the flow passage,
Useful for accurate concentration measurement of specific element components.

Further, since the second flow cell is provided at a lower position below the first flow cell, the pressure loss of the fluid sent from the first flow cell to the second flow cell can be reduced, and the fluid can be smoothly removed. It can be fed into a two-flow cell. This is particularly effective when the fluid is a liquid.

Further, in the above-mentioned measuring apparatus, a processing means for obtaining the concentration of a specific element by analysis based on a spectrum obtained by a detection signal from a fluorescent X-ray detector is provided, so that the measurement can be performed efficiently. , Continuous monitoring is also realized. That is, X-rays, γ-rays, and other radiations are radiated to the collected object, and the fluorescent X-rays generated from the collected object can be spectrally counted by, for example, a proportional counter. The spectrum analysis is performed based on.

Further, a processing means is provided, in which a plurality of specific types of elements are to be measured, and the concentration of each type of element is determined by analysis based on a spectrum obtained from a detection signal from a fluorescent X-ray detector. In addition, the concentration measurement of a plurality of specific element components can be performed simultaneously and continuously. Therefore, for example, by measuring a plurality of specific elements in the secondary system feedwater of a nuclear power plant, it is possible to grasp and identify in detail which part of the secondary system and which equipment is undergoing corrosion. It becomes possible. More specifically, for example, by measuring the iron concentration, it is possible to predict the progress of corrosion of the secondary piping or turbine, and by measuring the copper concentration, it is possible to predict the corrosion state of the condenser or the like.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings.

The concentration measuring apparatus according to the present embodiment uses iron (F) contained in the secondary system feed water of a pressurized water reactor at a nuclear power plant.
e) and two types of elements, copper (Cu), are the specific elements to be measured. As shown in FIG.
The supply of the secondary system water is performed by sampling the secondary system coolant condensed in the condenser 2 and flowing to the steam generator 3 through the sampling pipe 4. 5 is a reactor pressure vessel, 6 is a pressurizer, 7 is a coolant pump, 8 is a turbine, and 9 is a water supply pump.

The concentration measuring device 1 includes first and second two flow cells 11 and 12, as shown in FIGS. The first flow cell 11 collects the Fe component and the Cu component present in the form of particles in the secondary system feed water, and includes a micromembrane filter 13 having a pore size of, for example, 0.45 μm. Second flow cell 12
Is a component that collects these element components existing in the form of ions, and includes an ion-exchange membrane filter 14.

Reference numeral 15 denotes a sampling line, 16 denotes an intermediate line, and 17 denotes a drain line. The flow passage according to the present invention is constituted by these lines. First, the sampling water from the sampling pipe 4 is sent to the first flow cell 11 through the sampling line 15 of the device 1 and passes through the micromembrane filter 13. By this passage, the particulate Fe component and the Cu component in the sampling water are collected by the micromembrane filter 13. Thereafter, the sampling water is sent to the second flow cell 12 through the intermediate line 16 and passes through the ion exchange membrane filter 14.
By this passage, F in the form of ions in the sampling water
The e component and the Cu component are collected by the ion exchange membrane filter 14. Then, the sampling water is discharged from the device 1 through the drain line 17. A flow meter 18 for measuring the flow rate of the sampling water is provided on the sampling line 15.

The inlet 19 of the sampling line 15
Is provided at a position higher than the first flow cell 11 in the measurement apparatus 1, and the sampling line 15 is piped so as to descend from the inlet 19 toward the first flow cell 11. I have. As a result, the pipe or hose constituting the sampling line 15
Among the e and Cu element components, it is possible to prevent the particulate matter from adhering and accumulating, and to smoothly feed the particulate matter into the first flow cell 11 without stagnation. Accurate concentration measurement can be realized.

The second flow cell 12 is provided below and below the first flow cell 11. Thereby, the first flow cell 11 to the second flow cell 12
The pressure loss of the sampling water sent through the intermediate line 16 can be reduced, and the sampling water can be smoothly fed into the second flow cell 12 without losing momentum.

Then, the first and second flow cells 11, 1
In each of 2, fluorescent X-ray detectors 21 and 22 are provided above the filters 13 and 14. As is well known, the fluorescent X-ray detectors 21 and 22 detect fluorescent X-rays generated by irradiating a sample with radiation such as X-rays or γ-rays. Quantitation can be performed. Each fluorescent X-ray detector 21,
22 is provided with a radiation source for irradiation in combination therewith. The radiation source is, for example, RI by ²⁴⁴ Cm,
Alternatively, an X-ray tube or the like is used.

The concentrations of the respective elements Fe and Cu are determined by the following processing means using signals from the respective fluorescent X-ray detectors 21 and 22. That is, FIG.
As shown in (1), the electric pulses from the fluorescent X-ray detectors 21 and 22 are sent to the multi-channel analyzer 24 via the amplifier 23. Then, the fluorescent X-ray spectrum data obtained by the multi-channel analyzer 24 in a predetermined time unit is successively accumulated and stored in the storage unit 26 of the computer 25 one after another. The CPU 27 performs program control based on the spectrum data,
The weight of each element of Fe and Cu is calculated by the spectrum analysis, and the concentration of each element of Fe and Cu is obtained from the weight and the sampling flow rate by the flow meter 18.

In this computer processing, since trace amounts of Fe and Cu in the secondary feed water are measured,
Perform moving average processing. That is, the data is sequentially stored in the storage unit 26,
Of the stored spectral data, a predetermined number of data is traced back from the present time and a predetermined number of data are integrated, and these spectra are integrated. Based on the integrated spectrum, the concentration of each element of Fe and Cu is determined. I have to ask.

The component materials constituting the flow cells 11 and 12 are preferably made of a material having a low impurity content and a low background. The fluorescent X-ray detectors 21 and 22 detect the radiation from the substances collected by the filters 13 and 14,
Background radiation from the flow cells 11 and 12 themselves is also detected, which acts disadvantageously in spectral analysis, and raises the detection lower limit of the specific element. Therefore, it is preferable to reduce the detection of the background radiation. In particular, when a plurality of specific element components such as Fe and Cu whose energy levels are close to each other are to be measured, the background can be reduced to facilitate spectral analysis of each element component. Can be Among the flow cells 11 and 12, the holder 28 holding the filters 13 and 14, in particular, includes the filters 13 and 14 and the detector 2.
The fluorescent X-ray detectors 21 and 22 are likely to detect a large amount of background radiation from the holder 28 because they are present between the first and second X-rays. Recommended. Examples of the above materials include C elements such as polyethylene and polycarbonate;
A synthetic resin mainly composed of H element, ceramic, and the like are preferably used.

FIGS. 4 to 8 show test results obtained by measuring the two types of elements, Fe and Cu, contained in the secondary feedwater of the pressurized water light water reactor using the above concentration measuring apparatus. FIG. 4 is an example of a spectrum. It can be seen that even if the amounts of Fe and Cu are very small, the weight of each can be accurately calculated by analysis based on this spectrum. 5 and 6 show that the sampling flow rate is 400
ml / min, and the measurement time was 5 minutes sampling at startup,
The result of continuously measuring the Fe concentration and the Cu concentration while performing the moving average process as the sampling at the rated output for 10 minutes is shown. From this result, by using this measurement device, the Fe concentration,
The Cu concentration is set to 0. Measurement can be performed in the order of several ppb to several hundred ppb, responsiveness is very good in the operation of increasing power, and the behavior of the concentration of Fe and Cu in the secondary water can be continuously monitored. Could be confirmed. FIG. 7 shows the Fe concentration divided into the particle concentration and the ion concentration, and FIG. 8 shows the Cu concentration divided into the particle concentration and the ion concentration. From these results, it was confirmed that, particularly for Cu, by performing the concentration measurement based on both the particle and ion forms, highly accurate concentration measurement was realized. Although the concentration of Fe in the form of ions was low, this was merely the fact that the Fe ion concentration in the sampling water happened to be low.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and it goes without saying that various changes can be made without departing from the spirit of the invention. Absent. For example, in the above embodiment, a specific element in the secondary system feedwater of the pressurized water reactor of a nuclear power plant is targeted, but the apparatus of the present invention is a boiling water reactor (BW).
R) using a specific element in the water supply, using a specific element in the water supply of a thermal power plant as a target, using it as an aid in controlling the quality of pure water used in semiconductor cleaning equipment, or using gas It can be effectively used for measurement, monitoring, inspection and the like of the concentration of a specific element contained therein, and there is no limitation on the application, and it can be effectively and effectively used for various applications. It goes without saying that various elements other than Fe and Cu can be measured. Furthermore,
In the above embodiment, two types of elements, Fe and Cu, are targeted. However, a configuration in which only one type of element is targeted, or conversely, three or more types of elements may be targeted.
Also, various filters may be used according to the change in the form. Further, three or more flow cells may be provided according to the form of the specific element to be collected. The flow cell may be any type that can hold the filter so that the fluid can pass through the filter properly, and various types of structures may be adopted according to the type of the fluid.

[0027]

As described above, the apparatus for measuring the concentration of a specific element in a fluid according to the present invention captures a specific element component in the fluid with a filter of a flow cell, and detects this by fluorescent X-ray analysis. Because it is configured in the measurement device of
Even if the amount of this specific element component is extremely small, the concentration can be measured with high accuracy, and the measurement is not troublesome and time-consuming, and the measurement frequency is increased to realize continuous measurement. be able to. Not only that, a plurality of flow cells are provided, and in each flow cell, a filter that collects a specific element component in a different form is provided, and a fluorescent X-ray detector is provided in each of these flow cells. Thus, two or more forms of a specific element component can be used as a basis for measuring the concentration of the specific element. Even when the specific element component contained in the fluid is extremely small, the concentration can be extremely high. It can be measured with high accuracy. In this case, the first filter is a micro-membrane filter that captures the particulate component, and the second filter is an ion-exchange membrane filter that captures the ion component. Accurate concentration measurement based on ionic components is possible.

Further, by providing the fluid introduction port of the flow passage at a position higher than the first flow cell, specific element components in the form of particles or the like can be transferred from the fluid introduction port to the first flow cell. It can be fed smoothly without adhering and accumulating in the flow passage. Further, by providing the second flow cell at a lower position below the first flow cell, the pressure loss of the fluid sent from the first flow cell to the second flow cell can be reduced, and the fluid can be smoothly transferred to the second flow cell. Can be sent.

Further, in the above-mentioned measuring apparatus, the object to be measured is a plurality of specific types of elements, and the concentration of each type of element is determined by analysis based on a spectrum obtained by a detection signal from the fluorescent X-ray detector. By providing the means, it is possible to simultaneously measure the concentrations of a plurality of specific element components.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view showing an embodiment of a measuring device.

FIG. 2 is a partial cross-sectional front view showing the entire configuration of the device.

FIG. 3 is an explanatory view showing an overall configuration of a pressurized water light water reactor.

FIG. 4 is an energy spectrum diagram obtained by the apparatus of the present invention.

FIG. 5 is a graph showing the results of continuous measurement of Fe concentration.

FIG. 6 is a graph showing the results of continuous measurement of Cu concentration.

FIG. 7 is a graph showing Fe concentration divided into particle concentration and ion concentration.

FIG. 8 is a graph showing the Cu concentration divided into the particle concentration and the ion concentration.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Concentration measuring apparatus 11 ... 1st flow cell 12 ... 2nd flow cell 13 ... Micromembrane filter (1st filter) 14 ... Ion exchange membrane filter (2nd filter) 15, 16, 17 ... Flow path 21, 22 ... Fluorescence X Line detector

Claims (6)

[Claims] 1. A flow path of a fluid containing a specific element to be measured is provided with at least first and second flow cells, wherein the first flow cell is present in the fluid in a first form. A first filter for collecting an element component is provided, and a second flow cell for collecting the element component present in a fluid in a second form different from the first form in the second flow cell. (2) a filter in a fluid, wherein each of the flow cells is provided with an X-ray fluorescence detector for detecting X-ray fluorescence emitted from a collected substance by irradiation of radiation. Element concentration measurement device. 2. The method according to claim 1, wherein the first filter comprises a micro-membrane filter for collecting particulate components, and the second filter comprises an ion-exchange membrane filter for capturing ions. 2. The apparatus for measuring the concentration of a specific element in a fluid according to claim 1, wherein two flow cells are provided in the flow passage downstream of the first flow cell. 3. 3. The apparatus for measuring the concentration of a specific element in a fluid according to claim 1, wherein the fluid introduction port of the flow passage is provided at a position higher than the first flow cell. 4. The specific element concentration measuring device according to claim 1, wherein the second flow cell is provided at a lower position below the first flow cell. 5. The fluid according to claim 1, further comprising processing means for analyzing the concentration of the specific element based on a spectrum obtained by a detection signal from the fluorescent X-ray detector. For measuring the concentration of specific elements in water. 6. An object to be measured is a plurality of specific elements,
6. A processing means for obtaining the concentration of each specific element by analysis based on a spectrum obtained by a detection signal from the fluorescent X-ray detector.
The apparatus for measuring the concentration of a specific element in a fluid according to any one of the above.