System for on-line measurement technology feed liquid radioactivity
Technical Field
The invention belongs to the field of nuclear industry, and particularly relates to a system for measuring radioactivity of process feed liquid on line.
Background
In the post-treatment process flow, the yield of the plutonium can be obtained by accurately measuring the content of the plutonium in each process flow, the running condition of the process is judged, and the running of the whole post-treatment process is monitored and controlled. The online analysis avoids the lag of the offline analysis in time, real-time data is obtained by analysis, the change condition of the process operation process can be fed back in time, and the real-time data is used for monitoring, controlling and optimizing the process. The method has direct relation with product quality, economic benefit, production safety and the like by analyzing the micro/trace plutonium in the process feed liquid on line, and can fully explain the reasonability and practicability of the process.
At present, X-ray fluorescence analysis is adopted for micro/trace plutonium in an online monitoring process point in a factory, but the micro/trace plutonium cannot be applied or the measurement effect is not ideal due to poor detection limit.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a system for measuring the radioactivity of process feed liquid on line, which can realize real-time on-line measurement and detection of the process feed liquid.
The technical scheme of the invention is as follows:
a system for on-line measuring the radioactivity of process feed liquid comprises a measuring device, a flow cell, a process flow path, a cleaning flow path, an air flow path, a control system and a signal acquisition system;
the flow-through cell is communicated with a process flow path; the measuring device and the flow cell are installed in a butt joint mode and are respectively arranged on the inner side and the outer side of the glove box or the niche;
the cleaning flow path is connected with the measuring device to remove the retained radioactive contamination;
the air flow path is used for providing power for the cleaning flow path and the process flow path;
the cleaning flow path and the air flow path are in control connection with the control system;
the signal acquisition system is connected with the measuring device.
Further, in the system for measuring the radioactivity of the process liquid on line, the measuring device comprises a sleeve, a photomultiplier and a detection control unit; the photomultiplier is in control connection with the detection control unit, and the photomultiplier and the detection control unit are both arranged in the sleeve; the sleeve is connected with the flow cell; the detection control unit is in signal connection with the signal acquisition system.
Further, in the system for online measurement of radioactivity of process feed liquid, the signal acquisition system comprises a control line and a multi-channel spectrometer; the detection control unit is connected with the multi-channel spectrometer through a signal and is connected with the instrument control cabinet through a control line.
Further, in the system for on-line measurement of the radioactivity of the process material liquid, the flow cell is provided with an exhaust port; the exhaust port is arranged on the flow cell component and used for exhausting gas in the gas-liquid separation process.
Further, in the system for measuring the radioactivity of the process material liquid on line, the flow cell is provided with a light-shielding interface; and the feed liquid in the flow cell returns to the process flow path through the light-resistant interface.
Further, in the system for measuring the radioactivity of the process material liquid on line, a filtering overflow device is arranged on a liquid inlet pipeline between the flow cell and the process flow path, and an overflow outlet of the overflow device is connected with the process flow path.
Further, in the system for measuring the radioactivity of the process material liquid on line, the control system comprises a flow path controller and an upper computer in signal connection with the flow path controller; the cleaning flow path and the air flow path are both connected to the same flow path controller.
Further, in the system for measuring the radioactivity of the process liquid on line, the cleaning flow path and the process flow path are respectively connected with different spraying ports of the spraying component in the flow cell.
Further, in the system for measuring the radioactivity of the process liquid on line, the spraying component comprises a mounting seat and at least two spraying ports; the mounting seat is provided with a mounting space with an opening facing the probe, and the spraying port is arranged in the mounting space.
The invention has the following beneficial effects:
(1) the process feed liquid is directly introduced into the flow cell to be contacted with the detection probe for detection and analysis, and then returns to the process flow path, so that the online real-time detection of the online process feed liquid can be realized.
(2) The photomultiplier and the detection control unit are arranged in the sleeve, and are connected and installed with a flange hole of a glove box (or a niche) through the sleeve, so that the interior of the box chamber and the exterior of the sleeve are isolated and sealed to prevent pollution, and once the photomultiplier and the electronic detection part are broken or damaged, the photomultiplier and the electronic detection part can be conveniently maintained or replaced. Meanwhile, the safety of a laboratory or a working factory and the health of operators are ensured, the maintainability and the service life of the radioactive site instrument can be effectively improved, and the long-term stable and effective operation of the online analysis device is realized.
(3) Through the unique spraying and cleaning structure, the problem that the probe of the detector is polluted by alpha aerosol after the online analysis device runs for a long time is solved.
(4) By adopting a closed sleeve installation design, the device components completely realize modularized installation and modularized disassembly, the field adaptability and the practicability of the device are greatly enhanced, the maintainability of the device in a radioactive place is effectively improved, and the long-term stable and effective operation of the device is realized;
(5) compared with an alpha single-channel counting method, an alpha energy spectrum analysis and an X-ray fluorescence analyzer, the device is convenient to maintain in the later period and low in cost; meanwhile, the radiation protection safety of the environment and personnel can be guaranteed.
(6) At present, the online measurement of plutonium in factories uses X-ray fluorescence analysis, and the biggest problem is that the lower limit of plutonium detection is too high to reach 10-3g/L; the device adopts a novel scintillator, and a probe directly contacts with process liquid, so that the problem that the concentration of micro/trace plutonium in an online process is lower than 10 is solved-3The problem of lack of monitoring of g/L is solved, and the lower limit of detection of plutonium reaches 10-5g/L, effectively reduces the lower detection limit and enlarges the range of plutonium concentration monitored by the process.
Drawings
FIG. 1 is a schematic structural diagram of a system for on-line measurement of radioactivity in process feed according to the present invention.
Fig. 2 is a schematic structural view of a spray part in the flow cell.
In the above drawings, 1, process flow path; 2. filtering the overflow device; 3. a flow-through cell; 4. an exhaust port; 5. a sleeve; 6. a light-resistant interface; 7. a measuring device; 8. cleaning a storage tank; 9. a flow path controller; 10. an air flow path; 11. a multichannel spectrometer; 12. a control line; 13. an instrument control cabinet; 14. and (4) a spraying port.
Detailed Description
The invention is described in detail below with reference to the figures and examples.
As shown in fig. 1, the present invention provides a system for on-line measurement of radioactivity of process feed liquid, which comprises a measuring device 7, a flow cell 3, a process flow path 1, a cleaning flow path, an air flow path 10, a control system and a signal acquisition system; the flow-through cell 3 is communicated with the process flow path 1; the measuring device 7 is installed in a butt joint mode with the flow cell 3, and the measuring device 7 and the flow cell 3 are respectively arranged on the inner side and the outer side of the glove box or the niche; the cleaning flow path is connected with the measuring device 7 to remove the retained radioactive contamination; the air flow path 10 is used for providing power for the cleaning flow path and the process flow path 1; the cleaning flow path and the air flow path 10 are in control connection with the control system; the signal acquisition system is connected with the measuring device 7.
As shown in fig. 2, the flow cell 3 is internally provided with a spray part for facilitating the matching of the process liquid and the cleaning liquid with the probe. The cleaning flow path and the process flow path are respectively connected with different spraying ports of the spraying component in the flow cell. Therefore, the process liquid can be continuously and uniformly sprayed to the probe, and the other spraying port can be independently used for cleaning the probe contamination.
Specifically, the spray component comprises a mounting seat and at least two spray ports 14; the mounting seat is provided with a mounting space with an opening facing the probe, and the spraying port is arranged in the mounting space. So, a plurality of mouths that spray are embedded in installation space actually, can be more inseparable cooperation between mouth and the probe sprays. In this embodiment, the process liquid and the cleaning liquid are loaded into the measuring chamber by using the air-borne manner of the spraying port as power.
The process flow path 1 is a pipeline through which process material liquid flows, a filtering overflow device 2 is arranged on the liquid inlet pipeline between the flow cell 3 and the process flow path 1, and an overflow outlet of the overflow device is connected with the process flow path 1. The flow cell 3 is provided with a light-proof interface 6; the feed liquid in the flow cell 3 returns to the process flow path 1 through the light-proof interface 6. An exhaust port 4 is arranged on the flow cell 3; the exhaust port 4 is arranged on the part of the flow cell 3 and is used for exhausting gas in the gas-liquid separation process.
The measuring device 7 comprises a sleeve 5, a photomultiplier and a detection control unit; the photomultiplier is in control connection with the detection control unit, and the photomultiplier and the detection control unit are both arranged in the sleeve 5; the sleeve 5 is in butt joint installation with a glove box (or a niche) through a flange; the flow cell 3 is connected with the other port of the sleeve 5; the detection control unit is in signal connection with the signal acquisition system.
The signal acquisition system comprises a control line 12 and a multi-channel spectrometer 11; the detection control unit is in signal connection with the multi-channel spectrometer 11, and the multi-channel spectrometer 11 is connected with an instrument control cabinet 13 through a control line 12; the photomultiplier transmits a signal to the detection control unit, and the detection control unit transmits the signal to the multichannel spectrometer 11 and then to the instrument control cabinet 13.
The control system comprises a flow path controller 9 and an upper computer in signal connection with the flow path controller 9; both the purge flow path and the air flow path 10 are connected to the same flow path controller 9. The upper computer is used for controlling the action of the flow path controller 9 so that the flow path controller 9 controls the cleaning liquid to enter and exit.
When the monitoring data is abnormal or the process is stopped, the cleaning solution flows through the pipeline from the cleaning storage tank 8 to wash the flow cell 3 so as to remove the radioactive contamination remained in the flow cell 3; in this embodiment, the motive force for the process flow path 1 and the purge flow path is provided by the air flow path 10.
In the invention, the process material liquid is directly introduced into the flow cell to be contacted with the detection probe for detection and analysis, and then returns to the process flow path, so that the online real-time detection of the online process material liquid can be realized. The photomultiplier and the detection control unit are arranged in the sleeve, and are connected and installed with a flange hole of a glove box (or a niche) through the sleeve, so that the interior of the box chamber and the exterior of the sleeve are isolated and sealed to prevent pollution, and once the photomultiplier and the electronic detection part are broken or damaged, the photomultiplier and the electronic detection part can be conveniently maintained or replaced. Meanwhile, the safety of a laboratory or a working factory and the health of operators are ensured, the maintainability and the service life of the radioactive site instrument can be effectively improved, and the long-term stable and effective operation of the online analysis device is realized.
In the embodiment, the embedded spraying structure of the double spraying openings ensures that the pollution is clean and special, and can reachThe probe is cleaned, the problem that the probe is polluted by alpha aerosol after long-term operation of online analysis is solved, and the scintillator material made of YAP (yttrium aluminum phosphate) or Ce (cerium nitrate) crystal materials is matched, so that no thin-film layer protection is needed between the probe and the process material liquid, direct contact with the process material liquid for measurement is realized, and the lower limit of detection is reduced. By adopting a closed sleeve installation design, the device components completely realize modularized installation and modularized disassembly, the field adaptability and the practicability of the device are greatly enhanced, the maintainability of the device in a radioactive place is effectively improved, and the long-term stable and effective operation of the device is realized; compared with an alpha single-channel counting method, an alpha energy spectrum analysis and an X-ray fluorescence analyzer, the device is convenient to maintain in the later period and low in cost; meanwhile, the radiation protection safety of the environment and personnel can be guaranteed. At present, the online measurement of plutonium in factories uses X-ray fluorescence analysis, and the biggest problem is that the lower limit of plutonium detection is too high to reach 10-3g/L; the device adopts a novel scintillator, and a probe directly contacts with process liquid, so that the problem that the concentration of micro/trace plutonium in an online process is lower than 10 is solved-3The problem of lack of monitoring of g/L is solved, and the lower limit of detection of plutonium reaches 10-5g/L, effectively reduces the lower detection limit and enlarges the range of plutonium concentration monitored by the process.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.