JP6302319B2 - Dibutyl phosphate measurement method and dibutyl phosphate measurement device - Google Patents

Description

  The present invention relates to a dibutyl phosphate measurement method and a dibutyl phosphate measurement device for measuring dibutyl phosphate contained in a solution.

  Spent nuclear fuel used for power generation in nuclear power generation can be reused by reprocessing. When reprocessing spent nuclear fuel (hereinafter referred to as LWR spent nuclear fuel) used in a light water reactor (LWR), it is performed at a reprocessing facility for LWR. On the other hand, when reprocessing spent nuclear fuel (hereinafter referred to as FBR spent nuclear fuel) used in a fast breeder reactor (FBR), it is performed at a reprocessing facility for FBR.

  Some of these reprocessing facilities perform a solvent extraction process during spent fuel reprocessing. Tributyl phosphoric acid (TBP) is used as a solvent used in the solvent extraction process or the like during the spent fuel reprocessing. The alkaline waste liquid (alkali concentrated waste liquid) after extracting radioactive substances such as uranium (U) and plutonium (Pu) using this solvent is temporarily stored in the storage tank in the high-level waste glass solidification process. Stored.

  Moreover, when processing using tributyl phosphoric acid, dibutyl phosphoric acid will be produced | generated as a degradation product. Thus, in order to monitor the state of treatment or to detect the state of waste liquid, dibutyl phosphate in the waste liquid may be measured. In addition, dibutyl phosphate may be measured in a solution other than the waste liquid discharged from the reprocessing facility. On the other hand, in Patent Document 1, dibutyl phosphate is measured using a gas chromatography method.

JP-A-7-146284

  If the alkaline waste liquid is measured by gas chromatography, the analysis accuracy is reduced and the frequency of maintenance of the apparatus is increased due to contamination of the sample introduction part. As another analysis method, there is chromatography performed in a liquid state. Here, when dibutyl phosphate is measured by chromatography, it may be affected by coexisting substances contained in the waste liquid, and noise may be superimposed on the measurement result, thereby reducing the accuracy of component analysis.

  Then, this invention makes it a subject to provide the dibutyl phosphoric acid measuring method and dibutyl phosphoric acid measuring device which can measure the dibutyl phosphoric acid contained in a solution with high precision.

  The present invention is a dibutyl phosphate measurement method for measuring dibutyl phosphate in a liquid to be inspected, the step of analyzing the liquid to be inspected and detecting the presence or absence of an interfering substance, and not containing the interfering substance In this case, the analysis is performed by liquid chromatography using the first reagent as an ion pair reagent to measure dibutyl phosphate, and when the interference substance is contained, the analysis is performed by liquid chromatography using the second reagent as an ion pair reagent. And measuring dibutyl phosphate.

  According to this configuration, dibutyl phosphate can be measured with high accuracy regardless of the presence or absence of the interfering substance by switching the ion pair reagent according to the presence or absence of the interfering substance.

  The interfering substance is preferably molybdenum.

  It is preferable that the first reagent is tetrahexylammonium and the second reagent is tetrabutylammonium.

  Moreover, it is preferable that the liquid to be inspected is a liquid discharged when reprocessing the spent nuclear fuel.

  The present invention is a dibutyl phosphate measuring apparatus for measuring dibutyl phosphate in a liquid to be inspected, comprising: an interfering substance detection unit that analyzes the liquid to be inspected and detects the presence or absence of the interfering substance; and a first reagent. A first measurement unit that performs analysis by liquid chromatography using an ion pair reagent to measure dibutyl phosphate, and a second measurement unit that measures dibutyl phosphate by performing analysis by liquid chromatography using a second reagent as an ion pair reagent. A measurement unit and a control device that, when not containing the interfering substance, causes the first measurement unit to perform measurement, and when containing the interfering substance, causes the second measurement unit to execute measurement. It is characterized by having.

  According to this configuration, dibutyl phosphate can be measured with high accuracy regardless of the presence or absence of the interfering substance by switching the ion pair reagent according to the presence or absence of the interfering substance.

  According to the present invention, dibutyl phosphoric acid contained in a solution can be measured with high accuracy.

FIG. 1 is a schematic configuration diagram of a spent nuclear fuel reprocessing facility according to the first embodiment. FIG. 2 is a flowchart regarding a method for reprocessing spent nuclear fuel. FIG. 3 is a schematic diagram illustrating a schematic configuration of the measurement apparatus. FIG. 4 is a flowchart illustrating an example of a processing operation of the measurement apparatus. FIG. 5 is a graph illustrating an example of a measurement result of a comparative example of the measurement apparatus. FIG. 6 is a graph illustrating an example of a measurement result of the measurement device.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  First, a spent nuclear fuel reprocessing facility and a reprocessing method in which a liquid (waste liquid) that is one of objects to be measured by the measuring apparatus according to the present embodiment will be described with reference to FIGS. 1 and 2. In addition, the measuring apparatus of a present Example can measure suitably the liquid in which dibutyl phosphoric acid is mixed, and the facility and apparatus which produce | generate a liquid are not limited to a reprocessing facility. That is, the measuring device can also measure dibutyl phosphate in liquids other than waste liquid generated in the reprocessing facility.

  The spent nuclear fuel reprocessing facility according to the present embodiment extracts a new nuclear fuel by extracting and reprocessing nuclear fuel materials such as uranium (U) and plutonium (Pu) contained in a plurality of different spent nuclear fuels. U products and U / Pu products are generated.

  FIG. 1 is a schematic configuration diagram of a spent nuclear fuel reprocessing facility according to the first embodiment. The reprocessing facility 1 is a single facility capable of reprocessing a plurality of different spent nuclear fuels. As different types of spent nuclear fuel, uranium fuel was used in boiling water reactor (BWR), BWR spent nuclear fuel, uranium fuel was used in pressurized water reactor (PWR) PWR spent nuclear fuel, B-MOX spent nuclear fuel using MOX fuel in boiling water reactor, P-MOX spent nuclear fuel using MOX fuel in pressurized water reactor, uranium fuel or MOX fuel in fast breeder reactor There are used FBR spent nuclear fuel.

  The multiple types of spent nuclear fuel differ in the fissile ratio of the fissile radioisotope of the nuclear fuel material contained in the spent nuclear fuel and the enrichment of the nuclear fuel material. Here, nuclear fuel materials include uranium and plutonium, and fissile radioisotopes include uranium 233, uranium 235, plutonium 239, plutonium 241 and americium 241. In the following description, the case where it is applied to plutonium as a nuclear fuel material will be described.

The spent nuclear fuel is different in the plutonium fissile ratio (Pu fissile ratio) in the spent nuclear fuel and the plutonium enrichment (Pu enrichment) in the nuclear fuel. Pu fissile rate is an index representing the ratio of fissile radioisotope to the total amount of plutonium. Plutonium fissionable isotopes are plutonium 239 ( ²³⁹ Pu) and plutonium 241 ( ²⁴¹ Pu). For this reason, the Pu fissile rate is obtained by “( ²³⁹ P + ²⁴¹ Pu) / Pu”. The Pu enrichment is an index representing the ratio of the content of plutonium to the total amount of uranium and plutonium. Therefore, the Pu enrichment is obtained by “Pu / (U + Pu)”. An index obtained by multiplying the Pu fissile rate and the Pu enrichment is the Pu fissile enrichment, and the Pu fissile enrichment is obtained by “( ²³⁹ P + ²⁴¹ Pu) / (U + Pu)”.

  Here, the loading fuel (for example, the MOX fuel) manufactured using the new nuclear fuel generated by the reprocessing is based on the request from the nuclear power generation facility side for the Pu fissile rate of the MOX fuel and the target Pu fissile rate. In addition, it is necessary to set the Pu enrichment of the MOX fuel to the target Pu enrichment. In other words, the Pu fissile enrichment of the MOX fuel needs to be the target Pu fissile enrichment.

  On the other hand, a plurality of types of spent nuclear fuels have different Pu fissile rates, and in particular, B-MOX spent nuclear fuel is the spent nuclear fuel with the lowest Pu fissile rate. Therefore, for example, if the MOX fuel manufactured using new nuclear fuel obtained by reprocessing the B-MOX spent nuclear fuel is the target Pu fissile rate, the Pu enrichment exceeds the upper limit enrichment, It is difficult to reprocess. For this reason, the reprocessing facility 1 of Example 1 has the following configuration. Hereinafter, with reference to FIG. 1, a reprocessing facility 1 for reprocessing a plurality of types of spent nuclear fuel described above will be described.

  As shown in FIG. 1, the reprocessing facility 1 includes a mechanical processing device (for example, a shearing device) 5, a dissolution device 6, a clarification device 7, a weighing device 8, a separation device 9, and a purification device 10. The enrichment adjusting device 11, the denitration device 12, and the fuel production device 13 are provided.

  The components of the spent nuclear fuel supplied to the mechanical processing device 5 are estimated in advance. The estimated component of the spent nuclear fuel can be calculated based on data such as the component before use and the burnup during use.

  The mechanical processing device 5 exposes the spent nuclear fuel contained in the spent fuel assembly by mechanical processing. At this time, since waste gas is generated when the spent nuclear fuel is mechanically processed by the mechanical processing device 5, the mechanical processing device 5 sends out the generated waste gas to a waste gas processing device (not shown). The mechanical processing device 5 supplies the spent nuclear fuel after the mechanical processing toward the melting device 6.

  The melting device 6 dissolves the spent nuclear fuel by putting the spent nuclear fuel after mechanical treatment into the melting tank storing nitric acid. The spent nuclear fuel dissolved in nitric acid becomes a fuel solution, and the dissolving device 6 supplies the fuel solution to the refining device 7.

  The clarification device 7 is composed of, for example, a centrifuge. The clarification device 7 removes the insoluble residue contained in the fuel solution that does not dissolve in nitric acid, and supplies the fuel solution from which the insoluble residue has been removed to the metering device 8. The removed insoluble residue is supplied to a waste storage tank (not shown).

  The metering device 8 receives the fuel solution for measuring the components in the fuel solution. The components in the fuel solution include, for example, nitric acid concentration, uranium amount, isotope ratio in uranium, plutonium amount, isotope ratio in plutonium, and the like. Then, from the components in the fuel solution, indices such as U enrichment, U fissile ratio, U fissile enrichment, Pu enrichment, Pu fissile ratio, Pu fissile enrichment, and the like that are actually measured values are derived. The metering device 8 supplies the fuel solution after metering to the separation device 9.

  The separation device 9 separates the uranium solution and the uranium / plutonium solution as solutions from the fuel solution. Specifically, the separation device 9 inputs an extraction solvent into the fuel solution to generate a uranium / plutonium loaded solvent that is an extraction solvent containing uranium and plutonium. Subsequently, the separation device 9 inputs a Pu back-extraction solvent into the uranium / plutonium loading solvent to extract a uranium / plutonium solution (hereinafter referred to as a U / Pu solution) that is a solution containing uranium and plutonium. Thereafter, the separation device 9 inputs the U back-extraction solvent into the uranium-loaded solvent that is the uranium / plutonium-loaded solvent after plutonium extraction, and extracts a uranium solution (hereinafter referred to as a U solution) that contains uranium. .

  The purifier 10 purifies the U solution and the U / Pu solution into a uranium nitrate solution (hereinafter referred to as a nitric acid U solution) and a uranium nitrate / plutonium solution (hereinafter referred to as a nitric acid U / Pu solution). The purification device 10 supplies the purified nitric acid U solution and the nitric acid U / Pu solution to the enrichment adjusting device 11.

  The enrichment adjusting device 11 adjusts the Pu enrichment by mixing the purified nitric acid U solution and the nitric acid U / Pu solution after heating and concentrating. Specifically, the enrichment adjusting device 11 adjusts the Pu enrichment of the nitric acid U / Pu solution by mixing the nitric acid U solution with the concentrated nitric acid U / Pu solution. The enrichment adjusting device 11 supplies the nitric acid U solution and the enriched nitric acid U / Pu solution to the denitration device 12.

  The denitration device 12 denitrates the nitric acid U solution and the nitric acid U / Pu solution after the enrichment is adjusted to obtain uranium oxide and uranium / plutonium oxide. The obtained uranium oxide and uranium / plutonium oxide are sent to the fuel production apparatus 13.

  The fuel production apparatus 13 stores uranium oxide (U product) and uranium / plutonium oxide (U / Pu product), and appropriately mixes the stored uranium oxide and uranium / plutonium oxide to load fuel. Is manufacturing.

  Next, with reference to FIG. 2, a series of flows relating to a spent nuclear fuel reprocessing method performed in the spent nuclear fuel reprocessing facility configured as described above will be described. FIG. 2 is a flowchart regarding a method for reprocessing spent nuclear fuel.

  When the fuel assembly containing the spent nuclear fuel whose component has been estimated in advance is supplied to the mechanical processing device 5, the mechanical processing device 5 converts the spent nuclear fuel contained in the supplied fuel assembly into the machine The mechanical processing step S <b> 1 to be exposed by the general processing is executed, and the spent nuclear fuel after the mechanical processing is supplied to the melting device 6. When the spent nuclear fuel is supplied to the melting device 6, the melting device 6 executes a melting step S2 for melting the supplied used nuclear fuel using nitric acid, and uses the dissolved spent nuclear fuel as a fuel solution. Supply toward the clarification device 7. When the fuel solution is supplied to the clarification device 7, the clarification device 7 executes a clarification step S <b> 3 to remove insoluble residues contained in the fuel solution, and supplies the fuel solution after clarification to the metering device 8. .

  When the fuel solution is supplied to the metering device 8, the metering device 8 causes the fuel solution to flow into the metering tank and executes a metering step S4 in which the components of the fuel solution accumulated in the metering tank are metered. Thereby, the error of the component of the fuel solution estimated before the measurement and the component of the fuel solution after the measurement is corrected. The fuel solution after measurement is supplied to the buffer tank. Thereafter, the process is repeated from S1 to S4 for the kind of spent nuclear fuel to be reprocessed. Thereby, different types of fuel solution are stored in the plurality of buffer tanks.

  When different types of fuel solution are collected, the mixing step S5 is executed, and different types of fuel solution are mixed and sent to the separation device 9. When the fuel solution is supplied to the separation device 9, the separation device 9 executes a separation step S6 for extracting uranium and plutonium in the fuel solution as a U / Pu solution and a U solution. When the U / Pu solution and the U solution are extracted, the separation device 9 supplies the U / Pu solution and the U solution to the purification device 10.

  When the U / Pu solution and the U solution are supplied to the purification device 10, the purification device 10 executes a purification step S7 for purifying the U solution and the U / Pu solution into a nitric acid U solution and a nitric acid U / Pu solution. Thereafter, the purification device 10 supplies the purified nitric acid U solution and the nitric acid U / Pu solution to the enrichment adjusting device 11. When the nitric acid U solution and the nitric acid U / Pu solution are supplied to the enrichment adjusting device 11, the enrichment adjusting device 11 mixes the solution after heating and concentrating the nitric acid U solution and the nitric acid U / Pu solution. Then, the enrichment adjustment step S8 for adjusting the Pu enrichment is performed. Thereafter, the enrichment adjusting device 11 supplies the nitric acid U solution and the enriched nitric acid U / Pu solution toward the denitration device 12.

  When the nitric acid U solution and the enriched nitric acid U / Pu solution are supplied to the denitration device 12, the denitration device 12 denitrates the nitric acid U solution and the nitric acid U / Pu solution to obtain uranium oxide and uranium / A denitration step S9 for generating plutonium oxide is performed. Thereafter, the denitration device 12 supplies uranium oxide and uranium / plutonium oxide to the fuel production device 13. When uranium oxide and uranium / plutonium oxide are supplied to the fuel production apparatus 13, the fuel production apparatus 13 temporarily stores the uranium oxide and uranium / plutonium oxide in a storage container, and stores the stored uranium oxide and uranium. / After appropriately mixing plutonium oxide, a fuel production step S10 for producing a loading fuel is performed.

  Next, a measuring device (dibutyl phosphate measuring device) that measures dibutyl phosphoric acid in waste liquid generated during processing in the refining device 7, for example, generated during processing in the reprocessing facility 1 as shown in FIG. 1 will be described. FIG. 3 is a schematic diagram illustrating a schematic configuration of the measurement apparatus.

  A measurement apparatus 100 illustrated in FIG. 3 performs an inspection target liquid supply unit 102 that supplies a liquid to be inspected (inspection target liquid), a first measurement unit 104 that measures the inspection target liquid, and measures the inspection target liquid. The second measurement unit 106, the liquid recovery unit 108 that recovers the inspection target liquid that has been inspected, the liquid to be supplied from the inspection target liquid supply unit 102 to the first measurement unit 104, or the first from the inspection target liquid supply unit 102 2 A three-way control valve 109 that switches whether to supply the liquid to the measurement unit 106, a control device 110 that controls the operation of each part, and a molybdenum detector 112 that detects molybdenum of the liquid to be inspected.

  The inspection target liquid supply unit 102 includes a liquid storage tank 120 and a liquid supply line 122. The liquid storage tank 120 stores the inspection target liquid. The liquid storage tank 120 can have various sizes, and may be a tank that stores a measurement sample, or may be a tank that stores waste liquid of a reprocessing facility. The liquid supply line 122 connects the liquid storage tank 120 and the three-way control valve 109. The inspection target liquid supply unit 102 supplies the inspection target liquid stored in the liquid storage tank 120 to the three-way control valve 109. The inspection target liquid supply unit 102 may supply the inspection target liquid toward the three-way control valve 109, and the configuration is not limited to this. For example, the liquid storage tank 120 may be directly connected to the three-way control valve 109 without providing the liquid supply line 122. In addition, the inspection target liquid supply unit 102 is preferably detachable from the three-way control valve 109. Thereby, every time the inspection target liquid is switched, the inspection target liquid supply unit 102 that supplies the inspection target liquid to the three-way control valve 109 can be switched.

The first measurement unit 104 uses the first reagent as an ion pair reagent, reacts the first reagent with dibutyl phosphate, and then converts the dibutyl phosphate in the liquid to be tested by high performance liquid chromatography (HPLC). measure. The first measurement unit 104 includes a first distribution line 130, a liquid feed pump 132, a first reagent tank 134, an injection control valve 136, a separation column 138, and a detector 139. Tetrahexyl ammonium (THA, (C ₆ H ₁₃ ) 4N +) is used as the first reagent.

  The first flow line 130 is connected to the three-way control valve 109, and the first flow line 130 circulates the inspection target liquid supplied from the three-way control valve 109. The first flow line 130 is arranged in the order of the liquid feed pump 132, the injection control valve 136, the separation column 138, and the detector 139 from the three-way valve 109 side. The liquid feed pump 132 flows the inspection target liquid in the first distribution line 130 in a predetermined direction. The first reagent tank 134 is a tank that stores the first reagent, and is connected to the injection control valve 136. The injection control valve 136 is a valve for switching whether to inject the first reagent supplied from the first reagent tank 134 into the first distribution line. The separation column 138 is a high-performance liquid chromatography column, and flows into the first flow line 130 and passes the liquid to be inspected into which the first reagent is injected. Since the separation column 138 has a different holding capability for each component (molecular weight or the like) contained in the liquid to be inspected that passes therethrough, the liquid to be inspected is separated for each component. The detector 139 detects the liquid to be examined that has passed through the separation column 138, and detects components based on high performance liquid chromatography.

The second measurement unit 106 uses the second reagent as an ion pair reagent, reacts the first reagent and dibutyl phosphate, and then measures dibutyl phosphate in the liquid to be inspected by high performance liquid chromatography. The second measurement unit 106 includes a second distribution line 140, a liquid feed pump 142, a second reagent tank 144, an injection control valve 146, a separation column 148, and a detector 149. The second reagent is tetrabutylammonium _{(TBA, (C 4 H 9} ) 4N +) is used. Since the second measurement unit 106 has the same configuration as the first measurement unit 104 except for the ion pair reagent, description of each part is omitted.

  The liquid recovery unit 108 is connected to the first distribution line 130 and the second distribution line 140, and the liquid to be inspected (liquid that has been inspected) that has passed through the first distribution line 130 and the second distribution line 140 is discharged.

  The three-way control valve 109 is connected to the liquid supply line 122, the first distribution line 130, and the second distribution line 140. The three-way control valve 109 switches the connection of the three lines. The three-way control valve 109 supplies the liquid from the inspection target liquid supply unit 102 to the first measurement unit 104 or supplies the liquid from the inspection target liquid supply unit 102 to the second measurement unit 106 by switching the line connection. Switch between.

  The control device 110 performs arithmetic processing and controls each part of the measurement device 100, for example, the three-way control valve 109, the liquid feed pumps 132 and 142, the injection control valves 136 and 146, and the detection units 139 and 149. The control device 110 executes processing based on the measurement result of the molybdenum detection unit 112.

  The molybdenum detector 112 measures molybdenum contained in the inspection target liquid. The molybdenum detector 112 of this embodiment measures molybdenum contained in the liquid stored in the liquid storage tank 120. The molybdenum detector 112 may detect only the presence or absence of molybdenum, or may detect the concentration of molybdenum.

  Next, processing operations executed by the measurement apparatus 100 will be described using FIGS. 4 to 6. FIG. 4 is a flowchart illustrating an example of a processing operation of the measurement apparatus. FIG. 5 is a graph illustrating an example of a measurement result of a comparative example of the measurement apparatus. FIG. 6 is a graph illustrating an example of a measurement result of the measurement device. The process illustrated in FIG. 4 can be executed by the control device 110 controlling the operation of each unit. The processing operation may be performed by an operator. Hereinafter, the processing executed by the control device 110 will be described.

The control device 110 analyzes the liquid to be inspected (inspection liquid) (step S12). Specifically, the presence or absence of molybdenum as an interfering substance is detected using the molybdenum detection unit 112. After analyzing the inspection target liquid, the control device 110 determines whether molybdenum is contained (step S14). The control device 110 may be set to determine that there is molybdenum when molybdenum is detected even a little, or may be set to determine that there is molybdenum when molybdenum exceeds a threshold value. When it is determined that the controller 110 does not have molybdenum (No in Step S14), the control device 110 performs analysis using the first reagent (Step S16). Specifically, the liquid supply line 122 and the first distribution line 130 are connected by the three-way control valve 109, the first reagent is introduced into the liquid to be examined by the first measurement unit 104, and detection is performed by high performance liquid chromatography. . Based on the detection result, control device 110 detects the peak of dibutyl phosphate that forms an ion pair with the first reagent, and measures the concentration of dibutyl phosphate from the peak. In addition, you may perform measurement, such as a density | concentration of the dibutyl phosphoric acid based on the detection result in a high performance liquid chromatography, by the calculation by another apparatus.

When it is determined that the controller 110 has molybdenum (Yes in Step S14), the control device 110 performs analysis using the second reagent (Step S18). Specifically, the liquid supply line 122 and the second distribution line 140 are connected by the three-way control valve 109, the second reagent is introduced into the liquid to be examined by the second measurement unit 106, and detection is performed by high performance liquid chromatography. . Based on the detection result, the control device 110 detects the peak of dibutyl phosphate that forms an ion pair with the second reagent, and measures the concentration of dibutyl phosphate from the peak.

  The measuring apparatus 100 can perform highly accurate measurement by switching the reagent to be used in accordance with the presence or absence of molybdenum. Specifically, when molybdenum is present, measurement using the first reagent can shift the detection peak 204 of dibutyl phosphate with respect to the solvent peak 202, as shown in FIG. The detection peak 204 of dibutyl phosphate overlaps with the peak 206 of molybdenum. On the other hand, when there is molybdenum, the measurement apparatus 100 performs measurement using the second reagent, so that the detection peak 204a of dibutyl phosphate is changed to the solvent peak 202a and the molybdenum peak as shown in FIG. The detection peak 204a of dibutyl phosphate can be appropriately detected.

  As described above, the measuring apparatus 100 can suitably analyze dibutyl phosphate even when a liquid containing molybdenum becomes a liquid to be inspected by switching the ion pair reagent to be used according to the presence or absence of molybdenum as an interfering substance. Moreover, when there is no molybdenum, the measuring apparatus 100 can analyze dibutyl phosphate with high accuracy by using the first reagent having higher detection sensitivity than the second reagent.

  In the above embodiment, the interfering substance is molybdenum, but other substances may be used as the interfering substance. When a substance having a detection peak overlapping with dibutyl phosphate is used as an interfering substance and there is an interfering substance, the same effect can be obtained by switching the ion pair reagent used and shifting the detection peak of dibutyl phosphate.

Moreover, the ion pair reagent used as the first reagent and the second reagent is not limited to tetrabutylammonium (TBA, (C ₄ H ₉ ) 4N +) and tetrahexyl ammonium (THA, (C ₆ H ₁₃ ) 4N +). For example, tetraethylammonium (TEA, (C ₂ H ₅ ) 4N +) may be used.

  In this example, analysis was performed using high performance liquid chromatography (HPLC), but other liquid chromatography can also be used.

  In the above embodiment, the first measurement unit 104 and the second measurement unit 106 are separate systems, and a measurement unit is provided for each reagent, so that measurement can be performed immediately under appropriate conditions corresponding to the reagent. . Note that the measuring apparatus 100 may switch only the reagent and use a common separation column and detector.

  In the present embodiment, the first reagent and the second reagent are used in two cases, but more reagents may be used as the ion pair reagent. By increasing the number of reagents, even when the types of interfering substances increase, the reagent to be used can be switched depending on the characteristics of the interfering substances contained in the liquid to be examined, and the measurement accuracy can be increased.

DESCRIPTION OF SYMBOLS 1 Reprocessing facility 5 Mechanical processing apparatus 6 Dissolution apparatus 7 Clarification apparatus 8 Weighing apparatus 9 Separation apparatus 10 Purification apparatus 11 Enrichment degree adjustment apparatus 12 Denitration apparatus 13 Fuel production apparatus 100 Measurement apparatus 102 Test object liquid supply part 104 1st measurement Unit 106 Second measurement unit 108 Liquid recovery unit 109 Three-way control valve 110 Controller 112 Molybdenum detection unit 120 Liquid storage tank 122 Liquid supply line 130 First distribution lines 132 and 142 Liquid feed pump 134 First reagent tank 136 and 146 Injection control Valves 138, 148 Separation columns 139, 149 Detector 140 Second flow line 144 Second reagent tank

Claims (4)

A dibutyl phosphate measurement method for measuring dibutyl phosphate in a liquid to be inspected,
Analyzing the liquid to be inspected and detecting the presence or absence of molybdenum ;
If not containing the molybdenum, dibutyl phosphate was measured by running an analysis by liquid chromatography using a tetra-hexyl ammonium ion pair reagent, if containing the molybdenum, tetrabutyl ammonium ion pair reagent And a step of performing analysis by liquid chromatography and measuring dibutyl phosphate, and a method of measuring dibutyl phosphate. The method for measuring dibutyl phosphate according to claim 1, wherein the liquid to be inspected is a liquid discharged during reprocessing of spent nuclear fuel.   The method for measuring dibutyl phosphate according to claim 1, wherein the liquid chromatography is high performance liquid chromatography. A dibutyl phosphate measuring device for measuring dibutyl phosphate in a liquid to be inspected,
An interfering substance detection unit that analyzes the liquid to be inspected and detects the presence or absence of molybdenum ;
A first measurement unit for measuring dibutyl phosphate by performing an analysis by liquid chromatography using tetrahexylbutylammonium as an ion pair reagent;
A second measurement unit that performs analysis by liquid chromatography using tetrabutylammonium as an ion pair reagent and measures dibutyl phosphate;
If not containing the molybdenum, to execute the measurement by the first measurement unit, if containing the molybdenum, and having a control unit for executing measurement by the second measurement unit Dibutyl phosphate measuring device.

Images