Online monitoring device for radioactive iron in water and online monitoring method for radioactive iron in water

Abstract

The invention discloses an online monitoring device for radioactive iron in water and an online monitoring method for radioactive iron in water. The online monitoring device for radioactive iron in water comprises an integrated enrichment-separation unit, a source preparation unit, a recovery rate measurement unit and a radioactivity measurement unit which are connected in sequence. According to the invention, full automation of enrichment, radiochemical separation, measurement and data processing of radioactive iron in water is realized through cooperation of intelligent integrated enrichment-separation, source preparation and measurement, and the problems of backward technical means, long time consumption, low efficiency and low automation degree of separation of 55Fe in exudate of a nuclear power plant at present are solved; and meanwhile, lots of manpower and resource consumption are saved for the nuclear power plant.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive substance measurement, and particularly relates to an on-line monitoring device for radioactive iron in water and an on-line monitoring method for radioactive iron in water. Background Art

[0002] Quick and accurate analysis of radioactive substances is the basis and key for environmental radiation monitoring and nuclear emergency monitoring. Iron-containing components in a nuclear power plant reactor will simultaneously generate 55 Fe and 59 Fe after neutron activation. 55 The half-life of 59 Fe is 2.73 a, and the characteristic X-ray emitted after orbital electron capture has an energy of 5.9 keV;

[0003] CZT (cadmium zinc telluride) crystal is a nuclear radiation detector material with excellent performance, having high detection efficiency and good energy resolution for X and γ rays, and can work at room temperature. By measuring the X-ray emitted by 55 Fe and the γ-ray emitted by 59 Fe through a CZT detector, quantitative measurement of radioactive iron is achieved.

[0004] 55 As a difficult-to-measure radionuclide, the conventional method has a complex process. The analysis of each sample conservatively estimates to take two days. The existing resource allocation in nuclear power plants is difficult to adapt to this low-efficiency method and needs to be improved. Therefore, simplifying the pretreatment process and realizing the automation of radiochemical separation, while improving the measurement process, so as to realize the full-process automation of radioactive measurement, can save a large amount of manpower and resource consumption for nuclear power plants, and will be the inevitable direction of the analysis technology for difficult-to-measure radionuclides including 55 Fe. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an improved on-line monitoring device for radioactive iron in water and an on-line monitoring method for radioactive iron in water.

[0006] The technical solution adopted by the present invention to solve its technical problem is: to provide an on-line monitoring device for radioactive iron in water, including an integrated enrichment-separation unit, a source preparation unit, a recovery rate measurement unit, and a radioactive measurement unit connected in sequence;

[0007] The integrated enrichment-separation unit is used to quantitatively enrich metal ions in the water sample and then separate and purify them to obtain the iron solution to be measured; the source preparation unit prepares iron in the iron solution into a planar source of iron through a double-pulse electrodeposition process; the recovery rate measurement unit is used to measure and calculate the recovery rate of radioactive iron for the planar source of iron; the radioactive measurement unit is used to measure and calculate the activity concentration of radioactive iron for the planar source of iron.

[0008] In some embodiments, the integrated enrichment-separation unit includes a water sample storage tank, a processing liquid storage bottle group, a multi-stage series resin column group, and an intelligent switching pump group; the multi-stage series resin column group includes a first cation resin column, an anion resin column, a second cation resin column, and an iron-specific resin column connected in series in sequence; the water sample storage tank is connected to the first cation resin column, and the processing liquid storage bottle group includes a first bottle group for providing processing liquid for the first cation resin and the second cation resin column, a second bottle group for providing processing liquid for the anion resin column, and a third bottle group for providing processing liquid for the iron-specific resin column; the intelligent switching pump group controls the on-off between the water sample storage tank and the processing liquid storage bottle group and the multi-stage series resin column group.

[0009] In some embodiments, the intelligent switching pump group includes a first pump group connected between the water sample storage tank and the first cation resin column, a second pump group connected between the first bottle group and the first cation resin column, a third pump group connected between the second bottle group and the anion resin column, and a fourth pump group connected between the third bottle group and the iron-specific resin column; the first bottle group is also connected to the second cation resin column through the second pump group.

[0010] In some embodiments, the source preparation unit includes an electrodeposition cell for receiving the iron solution to be measured from the integrated enrichment-separation unit, and a first electrode plate and a second electrode plate arranged in the electrodeposition cell;

[0011] The first electrode plate and the second electrode plate are respectively connected to the positive and negative poles of direct current. Under the action of the electric field, iron in the iron solution deposits on the surface of the first electrode plate to form a planar source of iron.

[0012] In some embodiments, the source preparation unit further includes an electrolyte storage bottle and a fifth pump group, and the fifth pump group is connected between the electrolyte storage bottle and the electrodeposition cell.

[0013] In some embodiments, the recovery rate measurement unit includes an XRD diffractometer; the XRD diffractometer is used to quantitatively emit X-rays and irradiate the surface of the planar source of iron to form diffraction.

[0014] In some embodiments, the radioactive measurement unit includes a shielding chamber, a CZT detector and a LaBr3 detector disposed in the shielding chamber; a planar source of iron is placed in the shielding chamber, and the radioactive nuclide 55 Fe emits X-rays, and the radioactive nuclide 59 Fe emits β-rays and γ-rays for collaborative measurement to achieve quantitative measurement of radioactive iron, and the activity concentrations of 55 Fe and 59 Fe are obtained by calculation.

[0015] The present invention also provides an on-line monitoring method for radioactive iron in water, which is implemented by using the on-line monitoring device for radioactive iron in water described in any one of the above, and the on-line monitoring method for radioactive iron in water includes the following steps:

[0016] S1. Under the action of the integrated enrichment-separation unit, the metal ions in the water sample are quantitatively enriched and then separated and purified to obtain a test iron solution;

[0017] S2. The iron in the iron solution is prepared into a planar source of iron through a double-pulse electrodeposition process;

[0018] S3. Measure and calculate the recovery rate of radioactive iron for the planar source of iron; and / or, measure and calculate the activity concentration of radioactive iron for the planar source of iron.

[0019] In some embodiments, the operation of measuring and calculating the recovery rate of radioactive iron for the planar source of iron is as follows: by quantitatively emitting X-rays and irradiating the surface of the planar source of iron to form diffraction, and combining with the X-ray diffraction spectrum of the standard substance, the diffraction intensity obtained from the water sample is analyzed and calculated to achieve quantitative analysis of iron elements and obtain the mass of the iron carrier in the planar source of iron; by combining with the amount of the iron carrier added to the water sample, the recovery rate of iron is calculated;

[0020] The recovery rate of the iron is calculated according to the following formula:

[0021]

[0022] In the formula: R is the recovery rate, %; Q is the mass of the iron carrier in the planar source of iron, mg; Q0 is the mass of the iron carrier added to the water sample, mg.

[0023] In some embodiments, in the measurement and calculation of the activity concentration of radioactive iron for the planar source of iron, 55 Fe and 59 Fe's activity concentration is calculated according to the following formula:

[0024]

[0025] Where: A is the activity concentration of the target radionuclide in the water sample, Bq / L; N net is the net counting rate, counts / s, that is, the total counting rate N total minus the background N bkg ; ε is the detection efficiency, %; η is the recovery rate of double-column collaborative separation and purification; V is the volume of the water sample, L; t is the measurement time, s; λ is the radionuclide decay constant; t col is the time interval from water sample collection to measurement, s.

[0026] Advantages of the present invention: Through the integration of the enrichment-separation unit, source preparation and measurement coordination, the intelligent enrichment and radiochemical separation, measurement and data processing of radioactive iron in water are realized, and the problems of backward separation technology means, long time consumption, low efficiency and low automation degree in the current nuclear power plant effluents are solved, while improving the efficiency and saving a large amount of manpower and resource consumption for the nuclear power plant. 55 For the separation of 55Fe, the problems of backward separation technology means, long time consumption, low efficiency and low automation degree are solved, while improving the efficiency and saving a large amount of manpower and resource consumption for the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0028] Figure 1 is a schematic logical connection diagram of an on-line monitoring device for radioactive iron in water according to an embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of an on-line monitoring device for radioactive iron in water according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] For a clearer understanding of the technical features, objectives and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings.

[0031] As Figure 1 and Figure 2 shown, an on-line monitoring device for radioactive iron in water according to an embodiment of the present invention may include an integrated enrichment-separation unit 10, a source preparation unit 20, a recovery rate measurement unit 30 and a radioactive measurement unit 40.

[0032] Among them, the integrated enrichment-separation unit 10 and the source preparation unit 20 are connected in sequence. The integrated enrichment-separation unit 10 is used to quantitatively enrich the metal ions in the water sample and then separate and purify them to obtain the iron solution to be measured. The source preparation unit 20 prepares the iron in the iron solution into a planar source of iron through a double-pulse electrodeposition process. The recovery rate measurement unit 30 is used to measure and calculate the planar source of iron to obtain the recovery rate of radioactive iron; the radioactive measurement unit 40 is used to measure and calculate the planar source of iron to obtain the radioactive iron ( 55 55Fe, 59The activity concentration of Fe). The recovery rate measurement unit 30 and the radioactivity measurement unit 40 are also connected to a terminal (such as a computer, a control platform, etc.), and the measurement results are output and sent to the terminal.

[0033] The integrated enrichment-separation unit 10 may further include a water sample storage tank 11, a processing liquid storage bottle group, a multi-stage series resin column group, and an intelligent switching pump group. The water sample storage tank 11 is connected to the multi-stage series resin column group, and the water sample is output from the water sample storage tank 11 and sent into the multi-stage series resin column group for multi-stage treatment. The processing liquid storage bottle group is connected to the multi-stage series resin column group to provide processing liquid for the multi-stage series resin column group. The intelligent switching pump group controls the on-off between the water sample storage tank and the processing liquid storage bottle group and the multi-stage series resin column group.

[0034] Specifically, the multi-stage series resin column group includes a first cation resin column 121, an anion resin column 122, a second cation resin column 123, and an iron-specific resin column 124 connected in series through pipelines in sequence. The water sample storage tank 11 is connected to the first cation resin column 121, and the iron-specific resin column 124 is connected to the radionuclide preparation unit 20. Thus, after the water sample enters the first cation resin column 121, through multi-stage treatment of the multi-stage series resin column group, quantitative enrichment of metal ions in the water sample is achieved and then separation and purification are carried out, and the formed iron solution to be measured is transported to the radionuclide preparation unit 20 through the iron-specific resin column 124.

[0035] In the multi-stage series resin column group, porous partitions are arranged between the resin columns to prevent the resin between the resin columns from mixing and control the solution flow rate. Preferably, a pressure sensor can be integrated on the side wall of each resin column to monitor the blockage state in real time and feedback it to the intelligent switching pump group. The intelligent switching pump group can perform operations such as stopping the pump or increasing the power according to the blockage state.

[0036] The processing liquid storage bottle group may further include a first bottle group, a second bottle group, a third bottle group, and a fourth bottle group.

[0037] Among them, the first bottle group can be connected to the first cation resin column 121 and the second cation resin column 123, and provide processing liquid for the first cation resin column 121 and the second cation resin column 123. The first bottle group may further include a cation column pretreatment liquid storage bottle 131 and a cation column desorption liquid storage bottle 132. The cation column pretreatment liquid storage bottle 131 is used to provide pretreatment liquid for the cation resin column to make the inside of the cation resin column have the required acidity and alkalinity. The cation column desorption liquid storage bottle 132 is used to store the cation column desorption liquid and provide the cation column desorption liquid for the cation resin column (including the first cation resin column 121 and the second cation resin column 123) to desorb the metal ions adsorbed by the cation resin.

[0038] The second bottle group is connected to the anion resin column 122 to provide a treatment solution for the anion resin column 122. The second bottle group includes an anion column pretreatment solution storage bottle 133 and an anion column desorption solution storage bottle 134. The anion column pretreatment solution storage bottle 133 is used to provide a pretreatment solution for the anion resin column 122 to make the interior of the anion resin column 122 have the required pH value. The anion column desorption solution storage bottle 134 is used to store the anion column desorption solution to provide the anion column desorption solution for the anion resin column 122 to desorb the metal ions adsorbed by the anion resin.

[0039] The third bottle group is connected to the iron-specific resin column 124 to provide a treatment solution for the iron-specific resin column 124. The third bottle group includes an iron-specific resin column pretreatment solution storage bottle 135 and an iron-specific resin column desorption solution storage bottle 136. The iron-specific resin column pretreatment solution storage bottle 135 is used to provide a pretreatment solution for the iron-specific resin column 124 to make the interior of the iron-specific resin column 124 have the required pH value. The iron-specific resin column desorption solution storage bottle 136 is used to store the iron-specific resin desorption solution to provide the iron-specific resin desorption solution for the iron-specific resin column 124 to desorb the iron ions adsorbed by the iron-specific resin column 124 to form an iron solution enriched with iron.

[0040] Corresponding to the connection of the water sample storage tank 11, the treatment solution storage bottle group and the multi-stage series resin column group, the intelligent switching pump group further includes a first pump group connected between the water sample storage tank 11 and the first cation resin column 121, a second pump group connected between the first bottle group and the first cation resin column 121, a third pump group connected between the second bottle group and the anion resin column 122, and a fourth pump group connected between the third bottle group and the iron-specific resin column 124; the first bottle group is also connected to the second cation resin column 123 through the second pump group.

[0041] Specifically, the first pump group includes a first peristaltic pump 141 and a first liquid mass flowmeter 151, and the first peristaltic pump 141 and the first liquid mass flowmeter 151 are arranged on the pipeline between the water sample storage tank 11 and the first cation resin column 121. That is: the water sample storage tank 11 is connected to the inlet end of the first peristaltic pump 141, the inlet end of the first liquid mass flowmeter 151 is connected to the outlet end of the first peristaltic pump 141, and the outlet end of the first liquid mass flowmeter 151 is connected to the inlet end of the first cation resin column 121. The first peristaltic pump 141 is used to provide a driving force to transport the water sample in the direction of the first cation resin column 121 and control the transport flow rate. The water sample in the water sample storage tank 11 is injected into the first cation resin column 121 through the first peristaltic pump 141 and the first liquid mass flowmeter 151 for metal ion enrichment. The first peristaltic pump 141 is a dual-channel peristaltic pump to control the injection flow rate of the water sample into the first cation resin column 121; the first liquid mass flowmeter 151 is used to monitor the water sample injection flow rate in real time and feedback it to the first peristaltic pump 141 and / or the control terminal.

[0042] The second pump group includes a first injection pump 142 and a second liquid mass flowmeter 152. The first injection pump 142 and the second liquid mass flowmeter 152 are arranged on the pipeline between the first bottle group and the first cation resin column 121. The first injection pump 142 is a high-precision injection pump, which controls the injection flow rate of the pretreatment liquid and the desorption liquid of the first bottle group into the first cation resin column 121. The second liquid mass flowmeter 152 monitors the injection flow rate in real time and feeds it back to the first injection pump 142 and / or the control terminal. The first injection pump 142 dynamically adjusts the pump speed according to the feedback data of the second liquid mass flowmeter 152 to match the preset volume threshold. The first injection pump 142 has an internal exception handling program. If the pressure sensor detects a blockage, it automatically flushes the resin column in the reverse direction.

[0043] The third pump group includes a second injection pump 143 and a third liquid mass flowmeter 153, which are arranged on the pipeline between the second bottle group and the anion resin column 122, and their functions and regulations are the same as those of the first injection pump 142 and the second liquid mass flowmeter 152. The fourth pump group includes a third injection pump 144 and a fourth liquid mass flowmeter 154, which are arranged on the pipeline between the third bottle group and the iron-specific resin column 124, and their functions and regulations are the same as those of the first injection pump 142 and the second liquid mass flowmeter 152.

[0044] When the integrated enrichment-separation unit 10 is working, first, the treatment liquid in the cation column pretreatment liquid storage bottle 131 is injected into the first cation resin column 121 through the first injection pump 142 for pretreatment. After the required acidity and alkalinity are achieved in the first cation resin column 121, the water sample in the water sample storage tank 11 is then transported to the first cation resin column 121 through the first injection pump 142, and the metal ions in the water sample are adsorbed by the first cation resin column 121. Then, the desorption liquid in the cation column desorption liquid storage bottle 132 is transported to the first cation resin column 121 and the anion resin column 122 through the first injection pump 142. The anion resin column 122 receives the desorption liquid from the first cation resin column 121 and adsorbs the iron ions in the desorption liquid, and some interfering ions (including copper ions, cobalt ions, nickel ions, lead ions, etc.) are discharged with the waste liquid. The second injection pump 143 injects the anion column desorption liquid in the anion column desorption liquid storage bottle 134 into the anion resin column 122 and the second cation resin column 123 in sequence, and some interfering ions (lead ions) are discharged with the waste liquid, and the iron ions are transferred to the second cation resin column 123. The first injection pump 142 injects the cation column desorption liquid in the cation column desorption liquid storage bottle 132 into the second cation resin column 123 and the iron-specific resin column 124 in sequence, and some interfering ions (zinc ions, lead ions) are discharged with the waste liquid, and the iron ions are transferred to the iron-specific resin column 124. The third injection pump 144 injects the iron-specific resin column desorption liquid in the iron-specific resin column desorption liquid storage bottle 136 into the iron-specific resin column 124, and after desorption, a separated and purified iron solution is obtained.

[0045] Understandably, the anion resin column 122 is pre-washed by injecting the anion column pretreatment liquid in the anion column pretreatment liquid storage bottle 133 to adjust the acidity and alkalinity inside the anion resin column 122. The second cation resin column 123 is pre-washed by injecting the cation column pretreatment liquid in the cation column pretreatment liquid storage bottle 131 to adjust the acidity and alkalinity inside the second cation resin column 123. The iron-specific resin column 124 is pre-washed by injecting the iron-specific resin column pretreatment liquid in the iron-specific resin column pretreatment liquid storage bottle 135 to adjust the required acidity and alkalinity inside the iron-specific resin column 124.

[0046] The intelligent switching pump group further includes a fourth injection pump 145, which is connected between the outlet of the iron-specific resin column 124 and the source preparation unit 20 to inject the iron solution into the source preparation unit 20.

[0047] Further, the source preparation unit 20 may include an electrodeposition cell 21, a first electrode plate 22 and a second electrode plate 23 disposed in the electrodeposition cell 21. The electrodeposition cell 21 is connected to the iron-specific resin column 124 and receives the iron solution from the integrated enrichment-separation unit 10. A fourth injection pump 145 is disposed on the pipeline connecting the electrodeposition cell 31 and the iron-specific resin column 124 to provide a driving force for transporting the iron solution. The first electrode plate 22 and the second electrode plate 23 are respectively connected to the positive and negative poles of a direct current power supply. Under the action of an electric field, iron in the iron solution is deposited on the surface of the first electrode plate 22 to form a planar source 200 of iron.

[0048] Preferably, the first electrode plate 22 and the second electrode plate 23 are respectively located on the upper and lower sides of the electrodeposition cell 21. The first electrode plate 22 and the second electrode plate 23 are preferably platinum plates. The electrodeposition cell 21 is preferably a glass electrodeposition cell.

[0049] The source preparation unit 20 further includes an electrolyte storage bottle 24 and a second peristaltic pump 25. The inlet end of the second peristaltic pump 25 is connected to the electrolyte storage bottle 24, and the outlet end of the second peristaltic pump 25 is connected to the electrodeposition cell 21. The second peristaltic pump 25 is used to transport the electrolyte in the electrolyte storage bottle 24 into the electrodeposition cell 21.

[0050] Specifically, the electrolyte in the electrolyte storage bottle 24 is a mixed solution of ammonium carbonate and ammonium dihydrogen phosphate.

[0051] When the source preparation unit 20 works, the electrolyte is transported into the electrodeposition cell 21 through the second peristaltic pump 25 and mixed with the iron solution entering the electrodeposition cell 21. A DC power supply is loaded at both ends of the first electrode plate 22 and the second electrode plate 23 to realize the electrodeposition of iron on the surface of the first electrode plate 22 to fabricate the planar source 200 of iron. In one embodiment, the effective area of the planar source 200 of iron is 78.5 mm 2 .

[0052] The recovery rate measurement unit 30 includes an XRD diffractometer 31. The XRD diffractometer 31 is used to quantitatively emit X-rays, irradiate on the surface of the planar source 200 of iron to form diffraction, and realize the quantification of iron; by combining the amount of iron carrier added to the water sample, the recovery rate of iron is further calculated.

[0053] The radioactivity measurement unit 40 includes a shielding chamber 41, a CZT detector 42 and a LaBr3 detector 43 disposed in the shielding chamber 41. The planar source 200 of iron is placed in the shielding chamber 41, and the X-rays emitted by the radioactive nuclide 55 Fe, the β-rays and γ-rays emitted by the radioactive nuclide 59 Fe are measured synergistically by the CZT detector 42 and the LaBr3 detector 43 to realize the quantitative measurement of radioactive iron, and by calculation, 55 Fe and 59Activity concentration of Fe.

[0054] Specifically, inside the shielding chamber 41, the CZT detector 42 and the LaBr3 detector 43 are arranged opposite to each other with a certain distance, and the planar source 200 of iron is placed between the CZT detector 42 and the LaBr3 detector 43. The shielding chamber 41 is preferably a lead chamber, which is specifically composed of multiple lead plates connected in a surrounding manner. The planar source 200 of iron, the CZT detector 42 and the LaBr3 detector 43 are shielded by the shielding chamber 41 to reduce the influence of the environment on the measurement results. 55 The characteristic X-rays emitted by Fe have an energy of 5.9 keV; 59 Fe emits β and γ rays. The energies of the β rays are 475 keV (51.2%) and 273 keV (48.5%) respectively, and the energies of the γ rays are 1.29 MeV (43%) and 1.09 MeV (57%) respectively. The CZT detector 42 has good energy resolution for X-rays and γ rays at room temperature, and the energy detection range is from 5 keV to 3 MeV; the energy detection range of the LaBr3 detector 43 is from 20 keV to 10 MeV. It can realize the measurement of the low-energy to high-energy coverage of 55 Fe and 59 Fe.

[0055] Furthermore, the on-line monitoring device for radioactive iron in water of some embodiments further includes waste liquid tanks, which are respectively used to collect the waste liquids discharged from the integrated enrichment-separation unit 10 and the source preparation unit 20. Multiple waste liquid tanks can be provided, corresponding to each unit one by one. For example, the first waste liquid tank 51 corresponds to the integrated enrichment-separation unit 10 and collects the waste liquid output by the integrated enrichment-separation unit 10. The second waste liquid tank 52 corresponds to the source preparation unit 20 and receives the waste liquid output by the source preparation unit 20.

[0056] Reference Figure 1 and Figure 2 , the on-line monitoring method for radioactive iron in water implemented by the on-line monitoring device for radioactive iron in water of the present invention may include the following steps:

[0057] S1. Quantitatively enrich the metal ions in the water sample through the intelligent switching pump group and the multi-stage series resin column group, and then separate and purify them to remove the interfering ions to obtain the separated and purified iron solution. This step S1 is implemented by the integrated enrichment-separation unit 10.

[0058] S2. Prepare the iron in the iron solution into the planar source 200 of iron through the double-pulse electro-deposition process. This step S3 is implemented by the source preparation unit 20.

[0059] S3. Measure and calculate the recovery rate of radioactive iron through the recovery rate measurement unit 30 for the planar source 200 of iron; and / or measure and calculate the activity concentration of radioactive iron through the radioactive measurement unit 40 for the planar source 200 of iron.

[0060] In some embodiments, the operation of measuring and calculating the recovery rate of radioactive iron from the planar iron source 200 is as follows: By quantitatively emitting X-rays and irradiating the surface of the planar iron source 200 to form diffraction, combined with the X-ray diffraction spectrum of the standard substance, the diffraction intensity obtained from the water sample is analyzed and calculated to achieve quantitative analysis of iron elements, and the mass of the siderophore in the planar iron source is obtained; By combining the amount of the siderophore added to the water sample, the recovery rate of iron is calculated.

[0061] The recovery rate of iron is calculated according to the following formula:

[0062]

[0063] Where: R is the recovery rate, in %; Q is the mass of the siderophore in the planar iron source, in mg; Q0 is the mass of the siderophore added to the water sample, in mg.

[0064] In some embodiments, in the measurement and calculation of the activity concentration of radioactive iron from the planar iron source 300, 55 Fe and 59 The activity concentrations of Fe are calculated according to the following formula:

[0065]

[0066] Where: A is the activity concentration of the target radionuclide in the water sample, in Bq / L; N net is the net counting rate, in counts / s, that is, the total counting rate N total minus the background N bkg ; ε is the detection efficiency, in %, calibrated by Geant4 simulation ( 55 Fe: ε X = 18.5%, 59 Fe: ε γ = 4.2%); η is the recovery rate of double-column co-separation and purification (measured η ≥ 99%); V is the volume of the water sample, in L; t is the measurement time, in s; λ is the radionuclide decay constant ( 55 Fe: λ = 9.85×10 -7 s -1 ; 59 Fe: λ = 1.26×10 -6 s -1 ); t col is the time interval from water sample collection to measurement, in s.

[0067] The above are only embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. An online monitoring device for radioactive iron in water, characterized in that: It includes an integrated enrichment-separation unit, a source making unit, a recovery rate measuring unit and a radioactivity measuring unit which are connected in sequence; The integrated enrichment-separation unit is used to quantitatively enrich the metal ions in the water sample and then separate and purify them to obtain the iron solution to be tested; The source preparation unit prepares the iron in the iron solution into a planar source of iron through a double-pulse electrodeposition process; The recovery rate measurement unit is used to measure and calculate the recovery rate of radioactive iron on the plane source of iron; The radioactivity measurement unit is used to measure and calculate the planar source of iron to obtain the activity concentration of radioactive iron.

2. The on-line monitoring device for radioactive iron in water according to claim 1, characterized in that: The integrated enrichment-separation unit includes a water sample storage box, a treatment liquid storage bottle group, a multi-stage series resin column group and an intelligent switching pump group; the multi-stage series resin column group includes a first cationic resin column, an anionic resin column, a second cationic resin column and an iron-specific resin column connected in series in sequence; The water sample storage box is connected to the first cationic resin column, and the treatment liquid storage bottle group includes a first bottle group for providing treatment liquid for the first cationic resin and the second cationic resin column, a second bottle group for providing treatment liquid for the anion resin column, and a third bottle group for providing treatment liquid for the iron special effect resin column; The intelligent switching pump group controls the connection and disconnection between the water sample storage box and the treatment liquid storage bottle group and the multi-stage series resin column group.

3. The on-line monitoring device for radioactive iron in water according to claim 2, characterized in that: The intelligent switching pump group includes a first pump group connected between the water sample storage box and the first cationic resin column, a second pump group connected between the first bottle group and the first cationic resin column, a third pump group connected between the second bottle group and the anionic resin column, and a fourth pump group connected between the third bottle group and the iron special effect resin column; the first bottle group is also connected to the second cationic resin column through the second pump group.

4. The on-line monitoring device for radioactive iron in water according to claim 1, characterized in that: The source making unit comprises an electrodeposition cell for receiving the iron solution to be tested from the integrated enrichment-separation unit, a first electrode sheet and a second electrode sheet arranged in the electrodeposition cell; The first electrode sheet and the second electrode sheet are connected to the positive electrode and the negative electrode of direct current respectively. Under the action of the electric field, iron in the iron solution is deposited on the surface of the first electrode sheet to form a planar source of iron.

5. The on-line monitoring device for radioactive iron in water according to claim 4, characterized in that: The source making unit further comprises an electrolyte storage bottle and a fifth pump group, and the fifth pump group is connected between the electrolyte storage bottle and the electrodeposition cell.

6. The on-line monitoring device for radioactive iron in water according to any one of claims 1 to 5, characterized in that: The recovery rate measurement unit includes an XRD diffractometer; The XRD diffractometer is used to quantitatively emit X-rays, which are irradiated on the plane source surface of iron to form diffraction.

7. The on-line monitoring device for radioactive iron in water according to any one of claims 1 to 5, characterized in that: The radioactivity measurement unit includes a shielding room, a CZT detector and a LaBr3 detector arranged in the shielding room; The plane source of iron is placed in the shielding room, and the radioactive nuclides are detected by the CZT detector and the LaBr3 detector. 55 Fe emits X-rays, radionuclides 59 The β-ray and γ-ray emitted by Fe are measured in coordination to achieve the quantitative measurement of radioactive iron. 55 Fe and 59 Activity concentration of Fe.

8. A method for online monitoring of radioactive iron in water, characterized in that: The method for online monitoring of radioactive iron in water is implemented by using the on-line monitoring device for radioactive iron in water according to any one of claims 1 to 7, and the on-line monitoring method for radioactive iron in water comprises the following steps: S1. Under the action of the integrated enrichment-separation unit, the metal ions in the water sample are quantitatively enriched and then separated and purified to obtain an iron solution to be tested; S2, preparing the iron in the iron solution to be tested into a plane source of iron by a double pulse electrodeposition process; S3. Measuring and calculating the recovery rate of radioactive iron on the plane source of iron; and / or measuring and calculating the activity concentration of radioactive iron on the plane source of iron.

9. The method for online monitoring of radioactive iron in water according to claim 8, characterized in that: The operation of measuring and calculating the recovery rate of radioactive iron by measuring the plane source of iron is as follows: quantitatively emitting X-rays, irradiating the surface of the plane source of iron to form diffraction, combining the X-ray diffraction spectrum of the standard substance, analyzing and calculating the diffraction intensity obtained from the water sample, realizing quantitative analysis of the iron element, and obtaining the mass of the iron carrier in the plane source of iron; calculating the recovery rate of iron by combining the amount of the iron carrier added to the water sample; The recovery rate of iron is calculated according to the following formula: Wherein: R is the recovery rate, %; Q is the mass of iron carrier in the plane source of iron, mg; Q0 is the mass of iron carrier added to the water sample, mg.

10. The method for online monitoring of radioactive iron in water according to claim 8, characterized in that: The activity concentration of radioactive iron is obtained by measuring and calculating the planar source of iron. 55 Fe and 59 The activity concentration of Fe is calculated according to the following formula: Where: A is the activity concentration of the target nuclide in the water sample, Bq / L; N net is the net counting rate, counts / s, i.e. the total counting rate N total Subtract background N bkg ; ε is the detection efficiency, %; η is the recovery rate of dual-column synergistic separation and purification; V is the volume of water sample, L; t is the measurement time, s; λ is the nuclide decay constant; t col is the time interval from water sample collection to measurement, s.

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