WO2023077467A1

WO2023077467A1 - On-line detection device and method for impurities in lead-bismuth coolant

Info

Publication number: WO2023077467A1
Application number: PCT/CN2021/129128
Authority: WO
Inventors: 曾献; 胡宸; 孙兆轩; 邹青; 张勇; 赵园; 罗益玮; 段承杰; 崔大伟; 林继铭
Original assignee: 中广核研究院有限公司; 中国广核集团有限公司; 中国广核电力股份有限公司; 岭东核电有限公司
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2023-05-11

Abstract

An on-line detection device (1) and method for impurities in a lead-bismuth coolant (3). The on-line detection device (1) for impurities in the lead-bismuth coolant (3) comprises a measurement channel (10), a pulse laser (20), an optical lens (30), and a spectrometer (40); the measurement channel (10) is connected between the top cover of a pressure vessel (2) and the lead-bismuth coolant (3) inside the pressure vessel (2); the pulse laser (20) and the spectrometer (40) are both provided above the top cover of the pressure container (2); the optical lens (30) is arranged in the measurement channel (10) and is located on an emitting light path of the pulse laser (20), and focuses a pulse laser beam emitted by the pulse laser (20) and refracts same to the surface of the lead-bismuth coolant (3) to generate plasma; the spectrometer (40) is connected to the measurement channel (10), and acquires the plasma to obtain the spectral line intensities of impurity elements. By means of cooperation of the measurement channel (10), the pulse laser (20), and the spectrometer (40), the content of impurities in the lead-bismuth coolant (3) can be accurately detected by LIBS, the urgent need for multi-element, in-situ, and remote online measurement and analysis of impurities in a lead-based alloy is met, and the online monitoring requirement for reactor operation is met.

Description

On-line detection device and method for impurities in lead-bismuth coolant

technical field

The invention relates to the technical field of impurity detection, in particular to an on-line detection device and method for lead-bismuth coolant impurities.

Background technique

The lead-based fast reactor is evaluated by the "Generation IV Nuclear Energy System International Forum (GIF)" as the first generation IV reactor that is expected to realize industrial demonstration and commercial application. The corrosion of lead and lead-bismuth coolants on structural steel is an urgent problem to be solved. key technical issues. The metal oxide impurities produced by the corrosion of lead and lead-bismuth coolants on structural steel may block the circuit and core flow channels, causing local blockage accidents, and endangering the safety of the reactor in severe cases.

In order to ensure the purity of the lead-bismuth coolant and avoid excessive deposition of solid oxide impurities to block the flow channel and affect the normal operation of the stack, it is necessary to measure and remove the metal, non-metallic impurities, corrosion products and Fission products to ensure that the impurity content in the coolant is within the allowable limits. Therefore, it is necessary to design a detection device or method to solve the above problems.

The traditional methods for analyzing the composition of radioactive substances include chemical analysis methods, XRFA, ICP/MS, and NAA. The above-mentioned traditional analysis methods not only limit the quality of sampling, but also take a long time for the analysis process, and usually require specific hot cells and equipment to cut Samples, sample preparation and analysis, and during the sampling process, the samples have been contaminated, which will seriously affect the test results; at the same time, offline sampling tests are mainly manual operations, and personnel safety protection is difficult. On the other hand, the on-line analysis after sampling belongs to room temperature measurement. Lead and bismuth are solid at room temperature. During the process of the lead and bismuth sample changing from liquid to solid in the reactor, the precipitation of impurities will affect the test results. Therefore, the above-mentioned traditional analysis methods cannot meet the requirements of real-time, online, accurate and rapid measurement.

technical problem

The technical problem to be solved by the present invention is to provide an online detection device for lead-bismuth coolant impurities and an online detection method for lead-bismuth coolant impurities.

technical solution

The technical solution adopted by the present invention to solve the technical problem is: provide an online detection device for lead-bismuth coolant impurities, which is installed on the pressure vessel, and the online detection device for lead-bismuth coolant impurities includes a measurement channel, a pulse laser, and an optical lens. and a spectrometer;

The measuring channel is connected between the top cover of the pressure vessel and the lead-bismuth coolant inside the pressure vessel; the pulse laser and the spectrometer are both arranged above the top cover of the pressure vessel;

The optical lens is arranged in the measurement channel and on the emission path of the pulse laser, and focuses and refracts the pulse laser beam emitted by the pulse laser onto the surface of the lead-bismuth coolant to generate plasma; the spectrometer is connected to The measurement channel collects the plasma to obtain the spectral line intensity of impurity elements in the lead-bismuth coolant.

Preferably, the pulsed lasers include two solid-state pulsed lasers for simultaneously emitting pulsed laser beams.

Preferably, the spectrometer is connected to the upper end of the measurement channel with its probe, and the upper end of the measurement channel is closed.

Preferably, a valve is provided at the lower end of the measurement channel close to the lead-bismuth coolant to control the on-off of the measurement channel.

Preferably, the diameter of the measuring channel is 20mm-100mm.

Preferably, the optical lens divides the measuring channel into upper and lower channel segments;

The lower channel section forms the refraction light path of the optical lens, and the upper channel section forms the collection light path of the spectrometer.

Preferably, the lead-bismuth coolant impurity online detection device also includes a measuring pipe, one end of the measuring pipe is connected to the top cover of the pressure vessel, and the other end is inserted into the lead-bismuth coolant; the inner channel of the measuring channel forms the the measurement channel described above.

The present invention also provides a method for online detection of impurities in lead-bismuth coolant, comprising the following steps:

S1. A pulsed laser beam is emitted by a pulsed laser and irradiated onto the surface of the lead-bismuth coolant in the reactor to generate plasma on the surface of the lead-bismuth coolant;

S2. Collect and detect the plasma by a spectrometer, and obtain the spectral line intensity of impurity elements in the lead-bismuth coolant;

S3. Quantitative analysis and calculation are carried out by an internal calibration method to obtain the content of impurity elements in the lead-bismuth coolant.

Preferably, in step S2, the spectrometer obtains the spectral line intensity value of the impurity element in the lead-bismuth coolant standard sample by detecting the lead-bismuth coolant standard sample in advance, and the different concentrations of each impurity element and the spectral line intensity at the different concentrations The value is fitted to a curve to form an internal calibration curve;

In step S3, according to the spectral line intensity value of the impurity element detected in step S2, the corresponding concentration value is obtained through the corresponding internal calibration curve, and the content of the impurity element is obtained.

Preferably, the lead-bismuth coolant standard sample includes a high-purity lead-bismuth matrix with a mass fraction≥99.999% and the following impurity elements: Fe, Cr, Ni; in the impurity elements, the content of Fe is 0.1ppm-50ppm, The content of Cr is 0.1ppm-100ppm, and the content of Ni is 10ppm-50000ppm.

Preferably, the impurity elements are combined with the high-purity lead-bismuth matrix in the form of impurity alloys through vacuum melting to prepare the lead-bismuth coolant standard sample.

Beneficial effect

The lead-bismuth coolant impurity online detection device of the present invention, through the cooperation of the measurement channel, pulse laser and spectrometer, realizes the accurate detection of the impurity content in the lead-bismuth coolant by laser-induced breakdown spectroscopy (LIBS), and solves the multi-element on-line measurement The urgent need for analysis to meet the online monitoring needs of reactor operation.

In addition, high temperature measurement can be realized, which can reduce measurement deviation caused by low temperature measurement, reduce human operation, and reduce high temperature and radioactive risks.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the structural representation of the lead-bismuth coolant impurity on-line detection device of an embodiment of the present invention on the pressure vessel;

Fig. 2 is the structural representation of the lead-bismuth coolant impurity online detection device of an embodiment of the present invention;

Fig. 3 is the spectrogram of the lead bismuth coolant standard sample impurity element that spectrometer detects among the present invention;

Fig. 4 is the internal calibration curve diagram of Ni in the lead-bismuth coolant standard sample in the present invention.

Embodiments of the present invention

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in Figures 1 and 2, the lead-bismuth coolant impurity online detection device 1 according to an embodiment of the present invention is installed on the pressure vessel 2 so as to be located above the reactor for online detection of lead-bismuth coolant impurities in the reactor. The lead-bismuth coolant impurity online detection device may include a measurement channel 10 , a pulse laser 20 , an optical lens 30 and a spectrometer 40 .

The measuring channel 10 is connected between the top cover (not shown) of the pressure vessel 2 and the lead-bismuth coolant 3 inside the pressure vessel 2 . Both the pulsed laser 30 and the spectrometer 40 are arranged above the top cover of the pressure vessel 2 , and the pulsed laser 30 emits a pulsed laser beam toward the measurement channel 10 . The optical lens 30 is arranged in the measurement channel 10 and is located on the emission path of the pulsed laser 30, focusing and refracting the pulsed laser beam emitted by the pulsed laser 30 onto the surface of the lead-bismuth coolant 3 to generate plasma on the surface of the lead-bismuth coolant 3 body. The spectrometer 40 is connected to the measurement channel 10, and is used for collecting plasma and obtaining the spectral line intensity of impurity elements in the lead-bismuth coolant 3 through analysis and the like. The spectrometer 40 can also be communicatively connected to the DCS system 4 of the nuclear power plant, and send the measurement results to the DCS system 4 of the nuclear power plant to realize remote detection.

Wherein, the measurement channel 10 provides a closed channel for the pulsed laser beam emitted by the pulse laser 30 to pass through the surface of the lead-bismuth coolant 3, and also provides a collection path for the spectrometer 40, and the spectrometer 40 collects the lead-bismuth coolant along the measurement channel 10 3 Plasma generated on the surface.

The diameter of the measuring channel 10 is 20mm-100mm. The optical lens 30 adopts a high-precision optical lens.

A valve 50 is provided at the lower end of the measuring channel 10 close to the lead-bismuth coolant 3 to control the on-off of the measuring channel 10 . The valve 50 is preferably located above the liquid level of the lead-bismuth coolant 3 . When the measurement is not being performed, the measurement channel 10 can be closed by the valve 50 to isolate the lead-bismuth coolant 3 from communicating with the external environment, reduce the pollution of the lead-bismuth aerosol in the measurement channel 10, and realize radioactivity containment.

In addition, the measuring channel 10 is closed by the valve 50 when no measurement is being performed, which is convenient for flushing, filtering and vacuumizing the inside of the measuring channel 10 .

Corresponding to the measuring channel 10 , the online detection device for lead-bismuth coolant impurities of the present invention further includes a measuring pipeline 11 . One end of the measuring pipe 11 is connected to the top cover of the pressure vessel 2, and the other end is inserted into the lead-bismuth coolant 3. The inner passage of the measuring pipe 11 forms the measuring channel 10 .

The measuring pipe 11 can be made of materials such as stainless steel.

On the top cover of the pressure vessel 2 , the upper end of the measurement channel 10 (that is, the measurement pipe 11 ) protrudes from the top cover, so as to connect the spectrometer 40 and receive the pulsed laser beam emitted by the pulsed laser 30 .

Specifically, the pulse laser 30 can be located on the side of the measurement channel 10 on the top cover, and the side of the measurement channel 10 is correspondingly provided with an entrance, and the pulsed laser beam emitted by the pulse laser 30 enters the measurement channel 10 through the entrance.

In this embodiment, the pulsed laser 30 includes two solid-state pulsed lasers for simultaneously emitting pulsed laser beams. Through the setting of two solid-state pulsed lasers 30, the dual-pulse laser beams can be irradiated on the lead-bismuth coolant 3, the measurement accuracy and detection limit can be improved, and the measurement of impurity elements at 1 ppm level can be realized.

Corresponding to the emission angle of the pulsed laser beam of the pulsed laser 30 , the optical lens 30 is set in the measurement channel 10 at a corresponding inclination angle to focus and refract the pulsed laser beam to the surface of the lead-bismuth coolant 3 placed under the measurement channel 10 .

Further, in the measurement channel 10, the outer periphery of the optical lens 30 cooperates with the inner wall of the measurement channel 10 to divide the measurement channel 10 into upper and lower channel segments. The lower channel section forms the refraction beam path of the optical lens 30 , with its surface facing the lower channel section, the optical lens 30 focuses and refracts the pulsed laser beam onto the surface of the lead-bismuth coolant 3 . The upper channel section forms the collection optical path of the spectrometer 40 , and the plasma generated on the surface of the lead-bismuth coolant 3 is collected by the spectrometer 40 through the optical lens.

In addition, the two channel sections separated by the optical lens 30 are not completely isolated, and can be ventilated, which is convenient for purging and vacuuming the measurement channel 10 .

On the top cover of the pressure vessel 2 , a spectrometer 40 with its probe is connected to the upper end of the measuring channel 10 and closes the upper end of the measuring channel 10 .

The lead-bismuth coolant impurity online detection device 1 of the present invention detects the impurities of the lead-bismuth coolant on-line, and the temperature range of the applicable working environment is from room temperature to 700°C; the measured elements include Pb and Bi main elements, and the measured impurity elements Including Fe, Cr, Ni, Co, Mn, I, Cs, Hg, Tl and other trace impurity elements. For Pb and Bi main elements, the measurement range: 40wt.%-60wt.%; for impurity elements, the detection limit is lower than 1ppm.

The lead-bismuth coolant impurity online detection method of the present invention, can adopt above-mentioned lead-bismuth coolant impurity online detection device 1 to realize, with reference to Fig. 1, 2, the lead-bismuth coolant online detection method of impurity of the present invention can comprise the following steps:

S1. A pulsed laser beam is emitted by the pulsed laser 20 and irradiated onto the surface of the lead-bismuth coolant 3 in the reactor, so that plasma is generated on the surface of the lead-bismuth coolant 3 .

S2. The plasma is collected and detected by the spectrometer 40, and the spectral line intensity value of the impurity elements in the lead-bismuth coolant is obtained.

According to the collected plasma, the spectral line intensity values detected by the spectrometer 40 include the spectral line intensity values of main elements such as Pb and Bi and the spectral line intensity values of impurity elements such as Fe, Cr, and Ni. The spectral line intensity values of impurity elements obtained therein are taken for quantitative analysis and calculation to obtain the corresponding content.

Specifically, the spectrometer 40 obtains the spectral line intensity values of the impurity elements in the lead-bismuth coolant standard sample by detecting the lead-bismuth coolant standard sample in advance, and fits the spectral line intensity values of different concentrations of each impurity element and the different concentrations to a curve , forming an internal calibration curve.

According to the spectral line intensity value of the impurity element detected in step S2, the corresponding concentration value is obtained through the corresponding internal calibration curve, and the content of the impurity element is obtained.

The standard sample of lead-bismuth coolant includes a high-purity lead-bismuth matrix with a mass fraction of 99.999% or above, and also includes the following impurity elements: Fe, Cr, Ni; among the impurity elements, the content of Fe is 0.1ppm-50ppm, and the content of Cr The content of Ni is 0.1ppm-100ppm, and the content of Ni is 10ppm-50000ppm. Impurity elements are combined with impurity alloys and high-purity lead-bismuth matrix through vacuum smelting to prepare lead-bismuth coolant standard samples.

For example, the spectrogram of the impurity elements in the lead-bismuth coolant standard sample obtained by detecting the lead-bismuth coolant standard sample is shown in Figure 3 (the main element Pb I: 363.974nm, Bi is not shown), where: Cr I: 357.877nm , Fe I: 385.980nm, Ni I: 352.454nm, Ni I: 361.938nm. Taking Ni as an example, the internal calibration curve obtained is shown in Figure 4, where the abscissa represents the concentration (C), and the ordinate represents the spectral line intensity value, the fitting equation y=0.00549+1.83713x, and the linear correlation coefficient of the fitting curve R ² =0.96706. According to the Ni spectral line intensity value detected in step S2, the concentration corresponding to the spectral line intensity value can be obtained through the internal calibration curve shown in FIG. 4 , thereby obtaining the Ni content.

In summary, the device and method of the present invention can realize multi-element detection, that is, it can simultaneously detect multiple impurity elements in lead-bismuth coolant, and improve the detection limit of impurity elements.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, all of which are equally included in the scope of patent protection of the present invention.

Claims

An online detection device for lead-bismuth coolant impurities, characterized in that it is set on a pressure vessel, and the online detection device for lead-bismuth coolant impurities includes a measurement channel, a pulse laser, an optical lens, and a spectrometer;

The measuring channel is connected between the top cover of the pressure vessel and the lead-bismuth coolant inside the pressure vessel; the pulse laser and the spectrometer are both arranged above the top cover of the pressure vessel;

The optical lens is arranged in the measurement channel and on the emission path of the pulse laser, and focuses and refracts the pulse laser beam emitted by the pulse laser onto the surface of the lead-bismuth coolant to generate plasma; the spectrometer is connected to The measurement channel collects the plasma to obtain the spectral line intensity of impurity elements in the lead-bismuth coolant.
The online detection device for lead-bismuth coolant impurities according to claim 1, wherein the pulse laser comprises two solid-state pulse lasers for simultaneously emitting pulse laser beams.
The online detection device for lead-bismuth coolant impurities according to claim 1, wherein the spectrometer is connected to the upper end of the measurement channel with its probe, and the upper end of the measurement channel is closed.
The on-line detection device for impurities in lead-bismuth coolant according to claim 1, characterized in that a valve is provided at the lower end of the measurement channel close to the lead-bismuth coolant to control the on-off of the measurement channel.
The online detection device for lead-bismuth coolant impurities according to claim 1, characterized in that the diameter of the measuring channel is 20mm-100mm.
The online detection device for lead-bismuth coolant impurities according to claim 1, wherein the optical lens divides the measurement channel into upper and lower two channel sections;

The lower channel section forms the refraction light path of the optical lens, and the upper channel section forms the collection light path of the spectrometer.
The on-line detection device for lead-bismuth coolant impurities according to claim 1, characterized in that the on-line detection device for lead-bismuth coolant impurities also includes a measuring pipe, one end of the measuring pipe is connected to the top cover of the pressure vessel, and the other One end is inserted into the lead-bismuth coolant; the inner channel of the measuring channel forms the measuring channel.
An online detection method for impurities in lead-bismuth coolant, characterized in that it comprises the following steps:

S1. A pulsed laser beam is emitted by a pulsed laser and irradiated onto the surface of the lead-bismuth coolant in the reactor to generate plasma on the surface of the lead-bismuth coolant;

S2. Collect the plasma by a spectrometer and detect it, and obtain the spectral line intensity value of the impurity elements in the lead-bismuth coolant;

S3. Quantitative analysis and calculation are carried out by an internal calibration method to obtain the content of impurity elements in the lead-bismuth coolant.
The online detection method for impurities in lead-bismuth coolant according to claim 8, characterized in that, in step S2, the spectrometer obtains the spectral line intensity of impurity elements in the lead-bismuth coolant standard sample by detecting the lead-bismuth coolant standard sample in advance Values, different concentrations of impurity elements and spectral line intensity values at different concentrations are fitted to curves to form an internal calibration curve;

In step S3, according to the spectral line intensity value of the impurity element detected in step S2, the corresponding concentration value is obtained through the corresponding internal calibration curve, and the content of the impurity element is obtained.
The method for online detection of impurities in lead-bismuth coolant according to claim 9, wherein the standard sample of lead-bismuth coolant includes a high-purity lead-bismuth matrix with a mass fraction ≥ 99.999% and the following impurity elements: Fe, Cr, Ni ; Among the impurity elements, the content of Fe is 0.1ppm-50ppm, the content of Cr is 0.1ppm-100ppm, and the content of Ni is 10ppm-50000ppm.
The method for online detection of impurities in lead-bismuth coolant according to claim 10, wherein the impurity element is combined with the high-purity lead-bismuth matrix by vacuum smelting to obtain the lead-bismuth coolant standard sample .