CN110780331A - Measuring device for nondestructively and rapidly analyzing micro-trace plutonium in solution - Google Patents

Abstract

The invention relates to a measuring device for non-destructive rapid analysis of trace plutonium in solution, comprising a shielding cover, a measuring cup, a photomultiplier tube and an outer cylinder shell; the shielding cover is matched with the outer cylinder shell to form a measurement chamber; Both the photomultiplier tube and the measurement cup are arranged in the measurement chamber; the bottom of the measurement cup is a novel scintillator material, which cooperates with the photomultiplier tube to ensure optical signal transmission. The beneficial effects of the present invention are as follows: 1. The measuring cup is a nested design, with a compact structure, and with the new scintillator material, the effective transmission of the optical signal is guaranteed, and the detection lower limit of the instrument is greatly reduced, and the detection lower limit of the plutonium can reach ^{10-10 6} g/L, the detection limit is comparable to the existing α counting method, and far lower than the detection limit of X-ray fluorescence method 10 ^‑3 g/L; 2. The measuring cup can be reused after simple cleaning.

Description

A measuring device for non-destructive rapid analysis of trace plutonium in solution

technical field

The invention belongs to the field of nuclear industry, and in particular relates to a non-destructive and rapid analysis device for measuring trace plutonium in a solution.

Background technique

During the spent fuel reprocessing process, a large amount of raffinate and washing liquid contain micro/trace amounts of plutonium. By accurately measuring the content of plutonium in the process flow, the yield of plutonium can be calculated, the operation of the process can be mastered, and the entire process can be controlled. Monitoring and control of aftertreatment process operation. Therefore, accurate, convenient and rapid determination of plutonium concentration has always been the key to post-processing process control analysis.

At present, the economical and practical micro/trace plutonium analysis still uses the traditional alpha counting method and X-ray fluorescence method. The alpha counting method has high sensitivity, reliability and stability, and the sample usually needs to be separated before it can be measured. Using alpha single-channel counting and alpha energy spectroscopy, both require tedious sample processing processes such as quantitative volume drop source, burning, drying, etc.; while liquid scintillation instrument analysis samples need to add scintillation fluid to generate radioactive organic waste. X-ray fluorescence method belongs to non-destructive analysis, but the instrument has more stringent requirements for X-ray protection and personnel safety, and the detection limit of the method is higher than that of alpha counting method.

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a non-destructive measuring device for rapidly analyzing trace plutonium in solution, which can ensure the effective transmission of optical signals and lower the detection limit.

The technical scheme of the present invention is as follows:

A measuring device for non-destructive rapid analysis of micro-trace plutonium in solution, comprising a shielding cover, a measuring cup, a photomultiplier tube and an outer cylinder shell; the shielding cover cooperates with the outer cylinder shell to form a measurement chamber;

Both the photomultiplier tube and the measurement cup are arranged in the measurement chamber; the bottom of the measurement cup is a YAP:Ce crystal, which cooperates with the photomultiplier tube to ensure optical signal transmission.

Further, in the above-mentioned measurement device for non-destructive rapid analysis of micro-trace plutonium in solution, the measurement cup is a nested device, the bottom is a novel scintillator material, and the cup body is a machined part, which is formed by gasket nesting and sealing combination. to make.

Further, in the above-mentioned measuring device for non-destructive rapid analysis of micro-trace plutonium in solution, the inner wall of the outer cylinder shell is provided with a photon reflection layer.

Further, in the above-mentioned measuring device for non-destructive rapid analysis of micro-trace plutonium in a solution, a pallet is provided on the outer cylinder shell, the pallet is matched with the shielding cover, and a sealing gasket is arranged between the two. .

Further, in the above-mentioned measuring device for non-destructive rapid analysis of trace plutonium in a solution, a travel switch capable of controlling the control element is provided on the pallet; the travel switch can be triggered by the shielding cover.

Further, the above-mentioned measuring device for non-destructive rapid analysis of micro-trace plutonium in solution further includes a light guide sheet, the light guide sheet is closely attached between the bottom of the measuring cup and the photon receiving window of the photomultiplier tube.

Further, the above-mentioned measuring device for non-destructive rapid analysis of micro-trace plutonium in a solution also includes a base member, and the base member includes an upper base and a lower base that are connected to each other; the upper base and the The outer cylinder shell is connected, and a control element is arranged in the lower base; the control element is controlled and connected with the photomultiplier tube.

Further, in the above-mentioned measuring device for non-destructive rapid analysis of trace plutonium in a solution, the upper base and the outer cylinder shell are connected by an end cover and a connecting cover.

The beneficial effects of the present invention are as follows:

1. The measuring cup is a nested design with a compact structure. With the new scintillator material, the effective transmission of the optical signal is guaranteed, and the lower detection limit of the instrument is greatly reduced. The lower detection limit of plutonium can reach 10 ^-6 g/L, and the detection limit Comparable to the existing α counting method, and far lower than the detection limit of X-ray fluorescence method 10 ^-3 g/L;

2. The measuring cup can be reused after simple cleaning;

3. The sample is directly placed in the measuring cup for measurement, which belongs to non-destructive analysis. Compared with the existing α counting method, the tedious sample processing and preparation process is omitted, and the sample analysis time is effectively shortened, so as to achieve the purpose of rapid analysis.

Description of drawings

FIG. 1 is a schematic structural diagram of a measuring device for non-destructive rapid analysis of trace plutonium in solution according to the present invention.

FIG. 2 is a schematic diagram of an appearance structure in an embodiment of the present invention.

In the above drawings, 1, the lower base; 2, the upper base; 3, the end cover; 4, the connection cover; 5, the outer cylinder shell; 6, the pallet; 7, the sealing gasket; 8, the light guide sheet; 9. Measuring cup; 10. Shielding cover; 11. Potentiometer adjusting knob; 12. First terminal; 13. Second terminal; 14. Power interface; 15. Travel switch; 16. Photomultiplier tube.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , the present invention provides a non-destructive measurement device for rapid analysis of trace plutonium in solution, comprising a shielding cover 10, a measuring cup 9, a photomultiplier tube 16 and an outer cylinder shell 5; the shielding cover 10 Cooperate with the outer cylinder shell 5 to form a measurement chamber; the photomultiplier tube 16 and the measurement cup 9 are both arranged in the measurement chamber; the bottom of the measurement cup 9 is a novel scintillator material, which is compatible with the photomultiplier The tubes 16 cooperate to ensure optical signal transmission. In addition to the function of a built-in photomultiplier tube 16 , the outer cylinder shell 5 is also provided with a photon reflection layer on its inner wall to function as a light-proof darkroom.

In this embodiment, the measuring cup 9 is a nested device, the bottom is a YAP:Ce crystal, and the cup body is a machined part, which is formed by nesting and sealing of gaskets.

In order to improve the photon transmission effect, this embodiment also includes a light guide sheet 8 , and the light guide sheet 8 is closely attached between the bottom of the measuring cup 9 and the photon receiving window of the photomultiplier tube 16 . This is done so as to transfer the photons generated by the sample and the scintillator in the measuring cup 9 to the photomultiplier tube 16 .

The outer cylinder shell 5 is provided with a support table 6, and the support table 6 cooperates with the shielding cover 10 to play a shielding role together. In order to achieve a sealing effect, a sealing gasket 7 is arranged between the two. The pallet 6 is provided with a travel switch 15 capable of controlling the control element; the travel switch 15 is two protruding cylinder pressure-contact switches embedded in the pallet 6 and can be triggered by the shielding cover 10 In order to cooperate with the shielding cover 10 for interlock control.

As shown in FIG. 2 , this embodiment also includes a base member, which includes an upper base 2 and a lower base 1 that are connected to each other; the upper base 2 is connected to the outer cylinder shell 5 , A control element is arranged in the lower base 1 ; the control element is controlled and connected with the photomultiplier tube 16 . The upper base 2 and the outer cylinder shell 5 are connected by an end cover 3 and a connecting cover 4 . The connection mode of the end cover 3 and the connection cover 4 has a tightening effect and is easy to disassemble. The connecting post, the insulating post, the power interface 14 and the potentiometer adjusting knob 11 connected with the control element are arranged on the front panel of the lower base 1, and the communication interface is arranged on the rear panel. The first terminal 12 and the second terminal 13 are respectively the positive and negative voltage test external wiring; the power interface 14 provides the socket for external power supply for the whole device; the potentiometer adjustment knob 11 adjusts and sets the high voltage of the photomultiplier tube 16 .

The measuring device for non-destructive rapid analysis of micro-trace plutonium in solution of the present invention, the measuring cup is designed with a compact mosaic structure, combined with novel scintillator materials, ensures the effective transmission of optical signals, greatly reduces the detection lower limit of the instrument, and has a high sensitivity to plutonium. The lower detection limit can reach 10-6g/L, the detection limit can match the existing α counting method, and is far lower than the detection limit of X-ray fluorescence method 10-3g/L; at the same time, due to this new scintillator and special structural design, The measuring cup of the device can be reused after simple cleaning; compared with the existing alpha counting method, the tedious sample preparation process is omitted, and the sample analysis time is effectively shortened, so as to achieve the purpose of rapid analysis; the sample demand is less than 0.7mL; compared with liquid scintillation spectrometer, it can avoid the increase of radioactive organic waste liquid due to measurement; compared with α single-channel counting method, α energy spectrum analysis and X-ray fluorescence analyzer, the device has obvious cost advantages, and The later maintenance cost is low, and it is suitable for large-scale monitoring and analysis in laboratories or factories.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their technical equivalents, the present invention is also intended to include such modifications and variations.

Claims (8)

1. A measuring device for nondestructively and rapidly analyzing microscratch plutonium in a solution is characterized in that: comprises a shielding cover, a measuring cup, a photomultiplier and an outer cylinder shell; the shielding cover is matched with the outer cylinder shell to form a measuring chamber;

the photomultiplier and the measuring cup are both arranged in the measuring chamber; ce crystal is arranged at the bottom of the measuring cup and is matched with the photomultiplier tube to ensure optical signal transmission.

2. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to claim 1, characterized in that: the measuring cup is a nested device, the bottom of the measuring cup is made of a novel scintillator material, the cup body is a machined part, and the measuring cup is formed by nesting and sealing the gasket.

3. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to claim 1, characterized in that: and a photon reflection layer is arranged on the inner wall of the outer cylinder shell.

4. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to claim 1, characterized in that: the outer cylinder shell is provided with a support platform, the support platform is matched with the shielding cover, and a sealing gasket is arranged between the support platform and the shielding cover.

5. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to claim 4, characterized in that: a travel switch capable of controlling the control element is arranged on the supporting platform; the travel switch is capable of being triggered by the shield cover.

6. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to any one of claims 1 to 5, characterized in that: the measuring cup also comprises a light guide sheet, and the light guide sheet is tightly attached between the bottom of the measuring cup and the photon receiving window of the photomultiplier.

7. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to any one of claims 1 to 5, characterized in that: the base component comprises an upper base and a lower base which are connected with each other; the upper base is connected with the outer cylinder shell, and a control element is arranged in the lower base; the control element is in control connection with the photomultiplier tube.

8. A measuring device for the non-destructive rapid analysis of microscratch plutonium in a solution according to claim 7, characterized in that: the upper base and the outer cylinder shell are connected through an end cover and a connecting cover.

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