阅读说明：本技术 一种在热室内调节镎、钚价态的装置及方法 (Device and method for adjusting valence states of neptunium and plutonium in hot chamber ) 是由 李峰峰 何辉 唐洪彬 叶国安 蒋德祥 刘金平 刘占元 李斌 申震 常尚文 郭建华 于 2020-04-26 设计创作，主要内容包括：本发明公开了一种在热室内调节镎、钚价态的装置,所述装置包括内筒、夹套筒、进样系统、出料系统、样品在线分析系统、调料鼓泡系统、液位测量系统、温度测量系统、压力测量系统。本发明所提供的装置适合于放射性、强腐蚀性场所使用,并且可以在热室内直接测量样品的吸光值,利用不同物质的光谱吸收峰来判断料液中的离子价态等信息。(The invention discloses a device for adjusting valence states of neptunium and plutonium in a hot chamber, which comprises an inner cylinder, a jacket cylinder, a sample feeding system, a discharging system, a sample online analysis system, a seasoning bubbling system, a liquid level measurement system, a temperature measurement system and a pressure measurement system. The device provided by the invention is suitable for places with radioactivity and strong corrosivity, and can directly measure the light absorption value of a sample in a hot chamber and judge information such as the ionic valence state in the feed liquid by using the spectral absorption peaks of different substances.)

1. A device for adjusting valence states of neptunium and plutonium in a hot chamber is characterized by comprising an inner cylinder, a jacket cylinder, a sample introduction system, a discharge system, a sample online analysis system, a seasoning bubbling system, a liquid level measurement system, a temperature measurement system and a pressure measurement system;

the inner cylinder comprises an inner cylinder main body, an upper end enclosure and a lower end enclosure, and the inner cylinder main body is detachably connected with the upper end enclosure and the lower end enclosure;

the clamping sleeve is arranged at the periphery of the lower part of the inner cylinder main body, and cooling water is filled between the clamping sleeve and the inner cylinder main body;

the sample introduction system comprises a feed pipe and a feed liquid inlet arranged on the inner cylinder main body, the feed pipe extends into the inner cylinder main body, and the outlet of the feed pipe faces downwards;

the discharging system comprises a discharging pipe and a discharging hole formed in the upper end enclosure, one end of the discharging pipe extends into the bottom of the inner barrel, and the other end of the discharging pipe is connected with the vacuum system for material pumping;

the sample online analysis system comprises a sampling pipe and a sampling port arranged on the upper end enclosure, the sampling pipe penetrates through the sampling port, one end of the sampling pipe extends into the bottom of the inner cylinder, the other end of the sampling pipe is connected with an online measurement sample pool, and a vacuum device is connected behind the online measurement sample pool; the online measurement sample pool is provided with an optical fiber interface, and the absorbance of the sample can be measured online;

the seasoning bubbling system comprises an air inlet pipe and a bubbler interface arranged on the upper end enclosure, the air inlet pipe penetrates through the bottom end of the bubbler interface and is connected with a bubbling annular pipe, and the other end of the air inlet pipe is connected with an air supply device;

the liquid level measuring system is used for measuring the liquid level based on a differential pressure method and comprises three liquid level measuring ports arranged on the upper end enclosure, three pressure sampling pipes respectively penetrate through the liquid level measuring ports and extend into the inner cylinder main body, and one ends of the pressure sampling pipes extending out of the upper end enclosure are respectively connected with a blowing device and a differential pressure transmitter;

the temperature measuring system comprises a temperature measuring port and a temperature sensor which are arranged on the upper end enclosure;

the pressure measurement system comprises a pressure measurement port arranged on the upper end enclosure and a pressure measurement device.

2. An apparatus for adjusting the valence of neptunium and plutonium in a thermal chamber according to claim 1, wherein the jacket is provided with a cooling water inlet and a cooling water outlet.

3. An apparatus for regulating the valence of neptunium and plutonium in a thermal chamber according to claim 1, characterized in that said bubbling ring is placed horizontally, flush with the bottom head.

4. An apparatus for regulating the valence of neptunium and plutonium in a thermal chamber according to claim 1 or 3, characterized in that the central circle of the bubbling annular tube has a diameter of 220mm, and 30 small holes with a diameter of 2mm are equally spaced, and the holes are directed towards the right lower side.

5. The device for adjusting the valence states of neptunium and plutonium in a hot chamber according to claim 1, characterized in that a spare pressure relief opening is arranged on the upper end enclosure.

6. The apparatus for adjusting the valence of neptunium and plutonium in a thermal chamber according to claim 1, characterized in that the top of the upper cover is provided with a vent.

7. The device for adjusting the valence of neptunium and plutonium in the thermal chamber according to claim 1, characterized in that a drain hole is arranged at the bottom of the lower end enclosure.

8. An apparatus for adjusting the valence of neptunium and plutonium in a thermal chamber according to claim 1, wherein two pressure measurement ports and two pressure measurement devices are provided.

9. An apparatus for regulating the valence of neptunium and plutonium in a hot chamber according to claim 1, characterized in that the tapping pipe is equipped with a valve; and an intermediate tank is arranged between the online measurement sample pool and the vacuum device.

10. A method for adjusting the valence of neptunium and plutonium using the device according to any one of claims 1 to 9, characterized in that it comprises the following steps:

(1) feeding the feed liquid to be adjusted in price into the device through a sample feeding system;

(2) and (3) testing the sample online analysis system: the pipeline is connected with the sample on-line analysis system, and the sample cell is connected with the spectrophotometer through an optical fiber interface on the on-line measurement sample cell; connecting the sample pool on the pipeline in series, sampling on line to carry out absorbance analysis on the sample;

setting integration time by taking a blank sample or a nitric acid solution without a target as reference, detecting for many times according to the Lambert-beer law to obtain an average value, and indicating that the online analysis system of the sample can measure the concentrations of the Np and Pu ions with different valence states on line if characteristic absorption peaks of the Np and Pu ions with different valence states appear at a specific wavelength;

(3) nitrogen oxide is fed into the feed liquid to be adjusted in price through a seasoning bubbling system, and Np and Pu ions in the feed liquid are oxidized; monitoring the temperature, pressure and liquid level of the feed liquid in the reaction process; respectively testing the ionic valence state and the content of a reducing agent in the feed liquid after the seasoning process and the seasoning are finished;

(4) after the oxidation and valence adjustment are finished, stirring in an air bubbling mode, and removing excessive nitrous acid in the solution; and (3) pumping the feed liquid into the sample pool through a negative pressure or diaphragm pump, and measuring the light absorption value of the sample on line.

(5) After the seasoning process is finished, sampling and analyzing the acidity of the feed liquid, if the acidity of the feed liquid does not meet the requirements of the subsequent extraction and separation process, gradually adding the calculated amount of nitric acid through the feed inlet until the acidity of the feed liquid meets the requirements of the subsequent process, and sampling and analyzing the concentration of a target substance.

Technical Field

The invention relates to the field of spent fuel post-treatment, in particular to a device and a method for adjusting valence states of neptunium and plutonium in a hot chamber.

Background

The nuclear fuel water method post-treatment is a technological process for treating irradiated nuclear fuel by using a chemical separation method which is performed in an aqueous solution, such as precipitation, solvent extraction, ion exchange and the like, is a general method in the nuclear fuel post-treatment, and generally comprises the following three steps: the first step is to remove the outer shell of the fuel element mechanically or chemically and dissolve the element core (metal or oxide) in nitric acid, which is called head-end treatment; stainless steel or zirconium alloy clad fuel elements are cut-and-leached by cutting the element into small pieces and then leaching the core with nitric acid without dissolving the outer shell. The second step is that the solution enters a separation process, which is the core link of nuclear fuel reprocessing and which functions to remove fission products, recover unspent and newly produced nuclear fuel material and separate it. And the third step is to make the separated and purified intermediate product undergo the processes of supplementary purification, concentration and conversion into the required final form, called tail end treatment.

In the water method post-treatment process, target material ions enter a solution after the target material is dissolved, and the target material ions need to be separated and purified through an extraction process. In order to obtain the required separation purity, multiple extractions (extraction of the target element into the organic phase) and back extractions (extraction of the target element into the aqueous phase) are often performed. The target ions with different valence states have different partition coefficients in the organic phase and the water phase, and in order to realize the extraction and back extraction processes, the target ions need to be adjusted to the required valence state, and the excessive reducing agent in the liquid flow needs to be destroyed, so as to be separated and purified step by step.

Meanwhile, the price adjusting process of the thermal test process research needs to be completed in a hot chamber. The hot chamber has strong radioactivity and strong corrosivity place, and the simple and easy container of adjusting price experimentation use usually carries out above-mentioned operation, has certain potential safety hazard and uncertainty, consequently needs design one kind and is suitable for the adjusting price device that radioactivity, strong corrosivity place used to can in time on-line monitoring reation kettle in target substance ion valence state etc. to it has real-time monitoring and control to adjust price reaction process.

Disclosure of Invention

In view of the defects in the prior art, the present invention aims to provide a device and a method for adjusting the valence states of neptunium and plutonium in a hot chamber, so as to be suitable for radioactive and highly corrosive places.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a device for adjusting valence states of neptunium and plutonium in a hot chamber comprises an inner cylinder, a jacket cylinder, a sample introduction system, a discharge system, a sample online analysis system, a seasoning bubbling system, a liquid level measurement system, a temperature measurement system and a pressure measurement system;

the inner cylinder comprises an inner cylinder main body, an upper end enclosure and a lower end enclosure, and the inner cylinder main body is detachably connected with the upper end enclosure and the lower end enclosure;

the clamping sleeve is arranged at the periphery of the lower part of the inner cylinder main body, and cooling water is filled between the clamping sleeve and the inner cylinder main body;

the sample introduction system comprises a feed pipe and a feed liquid inlet arranged on the inner cylinder main body, the feed pipe extends into the inner cylinder main body, and the outlet of the feed pipe faces downwards;

the discharging system comprises a discharging pipe and a discharging hole formed in the upper end enclosure, one end of the discharging pipe extends into the bottom of the inner barrel, and the other end of the discharging pipe is connected with the vacuum system for material pumping;

the sample online analysis system comprises a sampling pipe and a sampling port arranged on the upper end enclosure, the sampling pipe penetrates through the sampling port, one end of the sampling pipe extends into the bottom of the inner cylinder, the other end of the sampling pipe is connected with an online measurement sample pool, and a vacuum device is connected behind the online measurement sample pool; the online measurement sample pool is provided with an optical fiber interface, and the absorbance of the sample can be measured online;

the seasoning bubbling system comprises an air inlet pipe and a bubbler interface arranged on the upper end enclosure, the air inlet pipe penetrates through the bottom end of the bubbler interface and is connected with a bubbling annular pipe, and the other end of the air inlet pipe is connected with an air supply device;

the liquid level measuring system is used for measuring the liquid level based on a differential pressure method and comprises three liquid level measuring ports arranged on the upper end enclosure, three pressure sampling pipes respectively penetrate through the liquid level measuring ports and extend into the inner cylinder main body, and one ends of the pressure sampling pipes extending out of the upper end enclosure are respectively connected with a blowing device and a differential pressure transmitter;

the temperature measuring system comprises a temperature measuring port and a temperature sensor which are arranged on the upper end enclosure;

the pressure measurement system comprises a pressure measurement port arranged on the upper end enclosure and a pressure measurement device.

Furthermore, a cooling water inlet and a cooling water outlet are arranged on the clamping sleeve.

Further, the bubbling annular pipe is horizontally arranged and is flush with the lower end enclosure.

Furthermore, the diameter of the central circle of the bubbling annular pipe is 220mm, 30 small holes with the diameter of 2mm are formed at equal intervals, and the holes face to the right lower part.

Furthermore, a standby pressure relief opening is formed in the upper end enclosure.

Further, the top of the upper end enclosure is provided with a vent.

Furthermore, a drain hole is formed in the bottom of the lower end enclosure.

Furthermore, pressure measurement mouth and pressure measurement device all set up two.

Furthermore, a valve is arranged on the discharge pipe; and an intermediate tank is arranged between the online measurement sample pool and the vacuum device.

The invention also provides a method for adjusting the valence states of neptunium and plutonium by using the device, which comprises the following steps:

(1) feeding the feed liquid to be adjusted in price into the device through a sample feeding system;

(2) and (3) testing the sample online analysis system: the pipeline is connected with the sample on-line analysis system, and the sample cell is connected with the spectrophotometer through an optical fiber interface on the on-line measurement sample cell; connecting the sample pool on the pipeline in series, sampling on line to carry out absorbance analysis on the sample;

setting integration time by taking a blank sample or a nitric acid solution without a target as reference, detecting for many times according to the Lambert-beer law to obtain an average value, and indicating that the online analysis system of the sample can measure the concentrations of the Np and Pu ions with different valence states on line if characteristic absorption peaks of the Np and Pu ions with different valence states appear at a specific wavelength;

(3) nitrogen oxide is fed into the feed liquid to be adjusted in price through a seasoning bubbling system, and Np and Pu ions in the feed liquid are oxidized; monitoring the temperature, pressure and liquid level of the feed liquid in the reaction process; respectively testing the ionic valence state and the content of a reducing agent in the feed liquid after the seasoning process and the seasoning are finished;

(4) after the oxidation and valence adjustment are finished, stirring in an air bubbling mode, and removing excessive nitrous acid in the solution; and (3) pumping the feed liquid into the sample pool through a negative pressure or diaphragm pump, and measuring the light absorption value of the sample on line.

(5) After the seasoning process is finished, sampling and analyzing the acidity of the feed liquid, if the acidity of the feed liquid does not meet the requirements of the subsequent extraction and separation process, gradually adding the calculated amount of nitric acid through the feed inlet until the acidity of the feed liquid meets the requirements of the subsequent process, sampling and analyzing the concentration of a target substance and the like.

The invention has the beneficial effects that:

(1) the experimental device oxidizes the reducing agent in the feed liquid containing Np and Pu under mild and controllable reaction conditions; the experimental device can be used for adjusting the valence state of ions in feed liquid containing Np and Pu and realizing the on-line measurement of the valence state and concentration of the ions; the experimental device can adjust the acidity of the feed liquid in the kettle to the acidity required by the process;

(2) the experimental device can monitor information such as liquid level height, pressure in the reaction kettle, temperature and the like in real time;

(3) the experimental device is corrosion-resistant, radiation-resistant, reliable in performance and long in service life; the pipeline, the valve and the like are connected in a quick mode, the operation of a manipulator is convenient, and the device is suitable for being used in a hot room.

Drawings

Fig. 1 is a schematic structural diagram of an apparatus for adjusting valence states of neptunium and plutonium in a hot chamber according to the present invention;

FIG. 2 is a schematic diagram of the sample on-line analysis system of the apparatus of the present invention;

FIG. 3 is a schematic view of the liquid level measuring system of the apparatus of the present invention;

wherein: 1, sealing an end socket; 2-lower end enclosure; 3-inner cylinder body; 4-a feed pipe; 5, a discharge pipe; 6-cooling water inlet; 7-a clean discharge port; 8, an air inlet pipe; 9-bubbling annular tube; 10-small holes; 11-a first pressure tapping pipe; 12-a second pressure tapping pipe; 13-third pressure tapping pipe; 14-sealing the sleeve; 15-a vent; 16-clamping the sleeve; 17-cooling water outlet.

Detailed Description

The invention is described in further detail below with reference to the drawings and the detailed description.

As shown in fig. 1, a device for adjusting valence states of neptunium and plutonium in a hot chamber comprises an inner cylinder, a jacket cylinder, a sample feeding system, a discharging system, a sample online analysis system, a seasoning bubbling system, a liquid level measurement system, a temperature measurement system and a pressure measurement system; the inner cylinder comprises an inner cylinder main body 3, an upper end enclosure 1 and a lower end enclosure 2, wherein the inner cylinder main body 3 is detachably connected with the upper end enclosure 1 and the lower end enclosure 2 through flanges and bolts.

The sampling system comprises a feed pipe 4 and a feed liquid inlet arranged on the inner cylinder main body, wherein the feed pipe extends into the inner cylinder main body, and the outlet of the feed pipe faces downwards. Feed liquid enters the gas-liquid separation tank from the lift tube and then flows into the inner barrel through the feed tube, the flow rate of the feed liquid is 210L/h, the pipe diameter of the feed tube is 25mm, and the diameter of the feed liquid inlet is 25 mm.

The seasoning bubbling system comprises an air inlet pipe 8 and a bubbler interface arranged on the upper end enclosure, the air inlet pipe 8 penetrates through the bottom end of the bubbler interface and is connected with a bubbling annular pipe 9, and the other end of the air inlet pipe is connected with an air supply device; the bubbling annular pipe 9 is horizontally arranged and is flush with the lower end enclosure; the diameter of the central circle of the bubbling annular pipe is 220mm, small holes 10 with the diameter of 2mm are arranged at equal intervals, and the number of the small holes is 30 in total, and the holes face to the right lower part. The price-adjusting bubbler serves two purposes, N₂O₄The mixed gas with air can be distributed through a bubbler and then reacts with the feed liquid; on the other hand, after the reaction, purge air was introduced through a bubbler for removing excess nitrous acid (HNO) in the solution₂)。

The discharging system comprises a discharging pipe 5 and a discharging hole formed in the upper end enclosure, one end of the discharging pipe 5 extends into the bottom of the inner barrel, and the other end of the discharging pipe is connected with the vacuum system for material pumping; the pipeline is additionally provided with a valve to control pressure drop or an air-pressure ejector to control vacuum degree, so that the feed liquid is prevented from being instantly sucked up. In order to vacate the space in the device and prevent the discharge pipe from being too close to the bubbling ring pipe, the smaller the discharge pipe is, the better the discharge pipe is, but simultaneously considering the risk of blockage at the elbow of the pipeline, the pipeline should not be too small, the discharge pipe with the diameter of 15mm is selected here, and the diameter of the discharge hole is also 15 mm.

As shown in fig. 2, the sample on-line analysis system comprises a sampling tube and a sampling port arranged on the upper end enclosure, the sampling tube passes through the sampling port, one end of the sampling tube extends into the bottom of the inner cylinder, the other end of the sampling tube is connected with an on-line measurement sample pool, and a vacuum device is connected behind the on-line measurement sample pool; an intermediate tank is arranged between the online measurement sample pool and the vacuum device; the on-line measurement sample pool is provided with an optical fiber interface, and the absorbance of the sample can be measured on line. The sample cell has the advantages of acid and alkali corrosion resistance, irradiation resistance, capability of realizing the rapid plugging of the optical fiber and the flow cell through a manipulator and the like. The sample on-line analysis process is shown in fig. 2, when a sample needs to be measured, the feed liquid is lifted to the intermediate tank by a vacuum or diaphragm pump for temporary storage, so that the feed liquid is filled in the on-line measurement sample pool. By measuring the position and the measured value of the absorption peak of the sample, the main substance species, the valence state composition and the approximate concentration range in the sample are obtained.

The liquid level measuring system is used for measuring the liquid level based on a differential pressure method and comprises three liquid level measuring ports arranged on an upper end enclosure, as shown in figure 3, a first pressure sampling pipe 11, a second pressure sampling pipe 12 and a third pressure sampling pipe 13 respectively penetrate through the liquid level measuring ports and extend into an inner cylinder main body, and one ends of the pressure sampling pipes extending out of the upper end enclosure are respectively connected with a blowing-up device and a differential pressure transmitter; the differential pressure liquid level measurement is realized by an air blowing method, and the diameters of a liquid level measurement port and a pressure tapping pipe are both 10 mm.

The temperature measuring system comprises a temperature measuring port and a temperature sensor which are arranged on the upper end enclosure. The temperature sensor adopts an armored core (phi 6, 316L, division number PT100 and a reinforcing pipe). Temperature measurement mouth department sets up sealed sleeve 14, and the sleeve pipe material is corrosion-resistant material, and the sleeve pipe internal diameter >6mm, and temperature sensor sets up in the sleeve pipe, with sleeve pipe threaded connection, can conveniently follow the sleeve pipe and dismantle on line, convenient maintenance, moreover can the totally enclosed nothing leak.

The pressure measurement system comprises a pressure measurement port arranged on the upper end enclosure and a pressure measurement device. The pressure in the equipment is small, and a differential pressure transmitter is used for measurement. The price adjustment process is violent in reaction, redundancy is considered in pressure measurement, and 2 differential pressure transmitters are arranged (a measuring element 316L, the precision is 0.075 grade, and an interface 1/2 NPT). For saving the cost, adopt the mode of blowing to measure, insert 10mm on the upper cover and press the pipe, the size of pressure measurement mouth also is 10mm, and pressure pipe adopts the cutting ferrule to connect moreover, easily dismantles.

The clamping sleeve 16 is arranged at the periphery of the lower part of the inner cylinder main body 3, and cooling water is filled between the clamping sleeve 16 and the inner cylinder main body 3; the clamping sleeve is provided with a cooling water inlet 6 and a cooling water outlet 17. According to the maximum heat exchange quantity, the heat quantity discharged by the feed liquid is reduced from 75 ℃ to 45 ℃, and the heat exchange rate q_J13957kJ/h, the required cooling water amount W can be found by calculation_{Water (W)}Is 0.667m³H, cooling water inlet,The diameter of the cooling water outlet pipe orifice is 20 mm.

And the top of the upper end enclosure is provided with a vent 15. The emptying design is as large as possible to reduce the air speed and avoid more liquid from being brought into the tail gas treatment system. Gas amount Q for bubbler is 5.0m³At/h, DN65 was taken at the vent, at which time the gas flow rate was 0.38 m/s.

The bottom of the lower end socket is provided with a clean discharge port 7. In order to conveniently drain the feed liquid in the kettle in the test stage, a drain port with the size of DN25 is arranged at the bottom of the kettle. And the method is cancelled during engineering equipment design so as to avoid leakage.

The upper end enclosure is also provided with a standby pressure relief opening, and the size of the opening of the standby pressure relief opening can be DN 40. The port is designed to meet pressure relief. The unfavorable conditions that may cause overpressure in the tank are:

a)N₂O₄feeding is out of control, after the feeding is rapidly carried out, the reaction releases heat in a short time, and the solution boils and gasifies to cause overpressure; b) when bubbling is used for blowing, the throttle valve on the main pipe is fully opened, and meanwhile, the vent is blocked, so that gas cannot be smoothly discharged, and overpressure is caused.

The method for adjusting the valence states of the neptunium and the plutonium by using the device comprises the following steps:

(1) feeding the feed liquid to be adjusted in price into the device through a sample feeding system;

(2) and (3) testing the sample online analysis system: the pipeline is connected with the sample on-line analysis system, and the sample cell is connected with the spectrophotometer through an optical fiber interface on the on-line measurement sample cell; connecting sample cells with certain optical distances in series on a pipeline, and sampling on line to perform absorbance analysis on the samples;

setting integral time by taking a blank sample or nitric acid without a target as reference, detecting for many times according to the Lambert-beer law to obtain an average value, and indicating that the online analysis system of the sample can measure the concentrations of the Np ions and the Pu ions with different valence states by detecting characteristic absorption peaks of complexes with different valence states of the Np ions and the Pu ions at specific wavelengths;

(3) nitrogen oxide is fed into the feed liquid to be adjusted in price through a seasoning bubbling system, and Np and Pu ions in the feed liquid are oxidized; monitoring the temperature, pressure and liquid level of the feed liquid in the reaction process; respectively testing the ionic valence state and the content of a reducing agent in the feed liquid after the seasoning process and the seasoning are finished;

(4) after the oxidation and valence adjustment are finished, stirring in an air bubbling mode, and removing excessive nitrous acid in the solution; and (3) pumping the feed liquid into the sample pool through a negative pressure or diaphragm pump, and measuring the light absorption value of the sample again.

(5) After the seasoning process is finished, sampling and analyzing the acidity of the feed liquid, if the acidity of the feed liquid does not meet the requirements of the subsequent extraction and separation process, gradually adding the calculated amount of nitric acid through the feed inlet until the acidity of the feed liquid meets the requirements of the subsequent process, sampling and analyzing the concentration of a target substance and the like.