JP6479398B2 - Reprocessing facility - Google Patents

Description

  The present invention relates to a reprocessing facility for reprocessing spent fuel used in a nuclear reactor.

  Conventionally, as a method of reprocessing spent fuel, there are reprocessing methods called a coprocessing method and a COEX (registered trademark) method. The coprocessing method and the COEX method are reprocessed from the viewpoint of non-proliferation so that plutonium is not isolated from spent fuel. Specifically, in the coprocessing method, uranium / plutonium loading containing uranium (U) and plutonium (Pu) is obtained by co-decontamination of a fuel solution in which spent fuel is dissolved using an extraction solvent and a cleaning solution. Solvent (U / Pu loaded solvent) is generated. The co-decontaminated U / Pu loading solvent flows into a distribution device provided in the reprocessing facility, and this distribution device allows uranium / plutonium solution (U / Pu solution) and uranium loading solvent (U loading solvent). And distributed. The dispensed U / Pu solution is extracted and washed using an extraction solvent and a washing solution, whereby a U / Pu loaded solvent is generated. And the produced | generated U / Pu loading solvent becomes a U / Pu solution by carrying out back extraction using a back extraction liquid.

  In the COEX method, in addition to the configuration of the coprocessing method, a uranium solution (U solution) is added to the generated U / Pu loading solvent, and a back extract is used as the U / Pu loading solvent to which the U solution is added. Thus, a U / Pu solution is generated by back extraction. In the COEX method, the U loading solvent is generated by back-extracting the U / Pu loading solvent, and the generated U loading solvent is allowed to flow into the distribution device into which the co-decontaminated U / Pu loading solvent flows. ing.

  Further, as a method for reprocessing so as not to isolate the plutonium from the spent fuel, the first stage extractor on the most water phase side is provided with a distribution device provided with a loaded solvent inlet and an extraction solvent inlet. A reprocessing facility is known (for example, Patent Document 1). In this reprocessing facility, the uranium / plutonium loaded solvent flows into the first stage extractor via the loaded solvent inlet, and the extracted solvent flows through the extraction solvent inlet. For this reason, since the solution back-extracted from the water phase side of the distributor is a U / Pu solution containing uranium, isolation of plutonium does not occur.

JP 2012-137344 A

  By the way, in the reprocessing facility, plural types of spent fuels having different plutonium content rates (Pu content rates) may be accepted. Further, in the reprocessing facility, it is necessary that the plutonium enrichment (Pu enrichment) of the purified U / Pu refined solution is the required Pu enrichment.

  At this time, in the coprocessing method, when the Pu content of the used fuel to be received is low (for example, 1%), in order to increase the Pu enrichment of the U / Pu solution, an aqueous solution and an extraction solvent (organic solvent) There is a processing step in which the O / A ratio, which is the ratio, is increased, and the amount of extraction solvent used increases, which may increase the reprocessing cost. Further, in the coprocessing method, the range of the Pu content of the used fuel to be received is narrow, and the adjustment range of the Pu enrichment of the U / Pu refined solution is narrow. On the other hand, in the COEX method, since the target of the Pu enrichment of the U / Pu solution is generally set to about 50%, it is difficult to adjust the Pu enrichment of the U / Pu solution. Become.

  Therefore, the present invention is a versatile reprocessing facility that can flexibly cope with fluctuations in the Pu content of the spent fuel to be accepted and fluctuations in the Pu enrichment of the uranium / plutonium solution to be refined. It is an issue to provide.

  The reprocessing facility of the present invention is a reprocessing facility that separates and reprocesses uranium and plutonium from a plurality of spent fuels having different plutonium contents, and into which co-decontaminated uranium / plutonium loading solvent flows. The uranium / plutonium loaded solvent that has flowed in is back-extracted with a back extract, thereby distributing the uranium / plutonium solution to the uranium loaded solvent and the uranium / plutonium solution distributed by the distributor. An extraction device that generates the uranium / plutonium loaded solvent by extracting with a solvent, and the uranium / plutonium loaded solvent generated by the extraction device by back extraction with a back extract, A back extraction device that distributes to the uranium loading solvent, the back extraction device from the extraction device to the uranium / pull The loading solvent inlet into which the nium loading solvent flows, the solution inlet into which the uranium solution flows, the back extraction liquid inlet into which the back extraction liquid flows, and the distributed uranium loading solvent to the distribution device And a loaded solvent outlet that flows out of the tank.

  According to this configuration, even when spent fuel with a high Pu content is reprocessed, uranium is mixed into the solution flowing out from the back extraction device by flowing the uranium solution into the back extraction device. Therefore, the uranium / plutonium solution can be purified without isolating the plutonium. In addition, since the uranium solution is allowed to flow into the back extraction device and the uranium loaded solvent that has flowed out of the back extraction device is allowed to flow into the distribution device, the content of uranium contained in the uranium / plutonium solution can be adjusted. It is possible to freely adjust the Pu enrichment of the uranium / plutonium solution to be purified. In this way, even when the Pu content of the spent fuel to be received fluctuates, the inflow amount of the uranium solution to the back extraction device is adjusted, or the inflow amount of the back extract to the back extraction device is adjusted. Or by adjusting the flow rate of the uranium-loaded solvent into the distributor, the uranium / plutonium solution having the required Pu enrichment can be purified. Therefore, it can be highly versatile and can flexibly cope with fluctuations in Pu content and fluctuations in Pu enrichment. The range in which the Pu content of the spent fuel to be accepted varies is, for example, 1 to 30%, and the range in which the Pu enrichment of the uranium / plutonium solution to be purified varies is, for example, It can be made into the range of 25-90%.

  In addition, a measuring device that measures the uranium content and the plutonium content contained in the uranium / plutonium loaded solvent that circulates from the extraction device to the back extraction device, and a control device that performs control based on the results of the measurement device It is preferable to further comprise.

  According to this configuration, the control device adjusts the inflow amount of the uranium solution to the back extraction device based on the Pu content contained in the uranium / plutonium loaded solvent flowing from the extraction device to the back extraction device. It is possible to adjust the inflow amount of the back extraction liquid into the back extraction device, or to adjust the inflow amount of the uranium loaded solvent into the distribution device. For this reason, the control device accurately adjusts the flow rates of the uranium solution, back-extracted solution, uranium loading solvent, etc. so that the Pu enrichment of the uranium / plutonium solution to be purified becomes the required Pu enrichment. can do.

  In addition, a first flow rate adjustment valve that adjusts the flow rate of the uranium solution flowing into the back extraction device via the solution inlet, and the flow that flows into the back extraction device via the back extraction solution inlet. Among the second flow rate adjustment valve that adjusts the flow rate of the back extract and the third flow rate adjustment valve that adjusts the flow rate of the uranium loaded solvent flowing out toward the distribution device via the loaded solvent outlet port, It is preferable that the apparatus further includes at least one flow rate adjustment valve, and the control device controls the flow rate adjustment valve based on a result of the measurement device.

  According to this configuration, the control device controls at least one of the first flow rate adjustment valve, the second flow rate adjustment valve, and the third flow rate adjustment valve on the basis of the measurement result of the measurement device. / Pu enrichment of plutonium solution can be adjusted with high accuracy.

  The tank further includes a tank that is provided upstream of the third flow rate adjustment valve in the flow direction of the uranium loading solvent flowing from the back extraction device to the distribution device and stores the uranium loading solvent. preferable.

  According to this configuration, the uranium loading solvent that has flowed out of the back extraction device can be temporarily stored in the tank, and the uranium loading solvent at a predetermined flow rate can be discharged from the tank to the distribution device. .

  In addition, when the uranium content contained in the uranium loaded solvent flowing out from the back extraction device through the loaded solvent outlet is equal to or less than the uranium content used as a used solvent, the uranium loaded solvent is It is preferable to discharge as a used solvent.

  According to this configuration, when the uranium content contained in the uranium loaded solvent flowing out from the back extraction device is almost zero, it can be discharged from the back extraction device as a used solvent.

FIG. 1 is a schematic configuration diagram of a reprocessing facility according to the present embodiment. FIG. 2 is a schematic configuration diagram around the separation device and the purification device in the reprocessing facility according to the present embodiment. FIG. 3 is a block diagram relating to partial control of the reprocessing facility according to the present embodiment. FIG. 4 is a schematic configuration diagram illustrating the distribution device and the U / Pu back extraction device according to the present embodiment. FIG. 5 is an external perspective view of the extractor.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. 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. Furthermore, the constituent elements described below can be combined as appropriate, and when there are a plurality of embodiments, the embodiments can be combined.

  FIG. 1 is a schematic configuration diagram of a reprocessing facility according to the present embodiment. FIG. 2 is a schematic configuration diagram around the separation device and the purification device in the reprocessing facility according to the present embodiment. FIG. 3 is a block diagram relating to partial control of the reprocessing facility according to the present embodiment. FIG. 4 is a schematic configuration diagram illustrating the distribution device and the U / Pu back extraction device according to the present embodiment. FIG. 5 is an external perspective view of the extractor.

  The spent fuel reprocessing facility 1 according to the present embodiment extracts nuclear fuel materials such as uranium (U) and plutonium (Pu) contained in a plurality of types of spent fuel having different plutonium content (Pu content). By reprocessing, a U product or U / Pu product as a new fuel is generated.

  As different types of spent fuel, uranium fuel was used in boiling water reactor (BWR), BWR spent fuel, uranium fuel was used in pressurized water reactor (PWR) PWR spent fuel, B-MOX spent fuel using MOX fuel in boiling water reactor, P-MOX spent fuel using MOX fuel in pressurized water reactor, uranium fuel or MOX fuel in fast breeder reactor There are used FBR spent fuel. Plural kinds of spent fuel differ in the content of plutonium in the fuel. The Pu content is an index that represents the ratio of the content of plutonium to the total amount of uranium and plutonium.

  The reprocessing facility 1 is a single facility capable of reprocessing a plurality of different spent fuels, and has a configuration in which plutonium cannot be isolated at the time of reprocessing spent fuel. Hereinafter, the reprocessing facility 1 will be described with reference to FIG.

  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 denitration device 11 and the fuel production device 12 are provided. In addition, the reprocessing facility 1 includes a control device 13 that controls each device.

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

  The mechanical processing device 5 exposes the spent fuel contained in the spent fuel assembly by mechanical processing. At this time, when the spent fuel is mechanically processed by the mechanical processing device 5, waste gas is generated. Therefore, 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 fuel after the mechanical processing to the melting device 6.

  The melting device 6 dissolves the spent fuel by putting the spent fuel after mechanical treatment into a melting tank storing nitric acid. The spent 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, indices such as U content and Pu content that are actually measured values are derived from the components in the fuel solution. The metering device 8 supplies the fuel solution after metering to the separation device 9.

  The separation device 9 separates the fuel solution into a uranium solution (U solution) and a uranium / plutonium solution (U / Pu solution). Details of the separation device 9 will be described later.

  The purifier 10 purifies the U solution and the U / Pu solution into a uranium nitrate solution (U product solution in FIG. 2) and a uranium nitrate / plutonium solution (U / Pu product solution in FIG. 2). The purifier 10 supplies the purified nitric acid U solution and nitric acid U / Pu solution to the denitration device 11.

  The denitration device 11 denitrates the nitric acid U solution and the nitric acid U / Pu solution to obtain uranium oxide and uranium / plutonium oxide. The obtained uranium oxide and uranium / plutonium oxide are sent to the fuel production apparatus 12.

  The fuel production apparatus 12 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, the separation device 9 and the purification device 10 will be specifically described with reference to FIG. As shown in FIG. 2, the separation device 9 includes a co-decontamination device 21 and a distribution device 22, and the purification device 10 includes a U / Pu extraction device 23, a U / Pu back extraction device 24, A 1U back extraction device 25, a U extraction device 26, and a second back extraction device 27 are provided.

  The co-decontamination device 21 supplies an extraction solvent to the fuel solution supplied from the metering device 8 to generate a uranium / plutonium loading solvent (U / Pu loading solvent) that is an extraction solvent containing uranium and plutonium. Then, the cleaning solution is supplied to the fuel solution to separate impurities contained in the fuel solution. That is, the fuel solution is separated in the co-decontamination apparatus 21 into a U / Pu loading solvent and a cleaning liquid (waste liquid) containing impurities other than uranium and plutonium. The co-decontamination device 21 supplies the U / Pu loading solvent to the distribution device 22, while discharging the cleaning liquid containing impurities as a waste liquid to a waste liquid receiving tank (not shown).

  The distribution device 22 separates the U / Pu solution and the U-loaded solvent by supplying the Pu back-extracted solution as the back-extracted solution to the U / Pu-loaded solvent supplied from the co-decontamination device 21. The distribution device 22 supplies the U / Pu solution toward the U / Pu extraction device 23, while supplying the U-loaded solvent toward the first U back extraction device 25.

  As shown in FIG. 4, the distributor 22 includes a plurality of extractors 40, a U / Pu loaded solvent inlet 51 into which the U / Pu loaded solvent supplied from the co-decontamination apparatus 21 flows, and a U / P described later. A U-loaded solvent inlet (loaded solvent inlet) 52 into which the U-loaded solvent supplied from the Pu back-extraction device 24 flows, and a back-extracted liquid inlet 53 into which a Pu back-extracted liquid for back-extracting plutonium flows And a U loaded solvent outlet 54 through which the U loaded solvent flows out.

  The plurality of extractors 40 have a multistage configuration arranged from the water phase side to the organic phase side. The extractor 40 is an extractor such as a mixer-settler, a pulse column, or a centrifugal extractor, and is configured to be separated into an aqueous phase and an organic phase. In this embodiment, a case where mixer settling is applied will be described, but the present invention is not limited to this configuration.

  As shown in FIG. 5, the extractor 40 includes a container 43 in which a mixing chamber 43a and a separation chamber 43b are formed, and a mixer 44 provided in the mixing chamber 43a. In the mixing chamber 43a of the container 43, a light liquid inlet 46 into which a light liquid on the organic phase side flows is formed at the upper part in the vertical direction, and a heavy liquid on the water phase side flows into the lower part in the vertical direction. An inflow port 47 is formed. In the separation chamber 43b of the container 43, a light liquid outlet 48 through which light liquid flows out is formed in the upper part in the vertical direction, and a heavy liquid outlet 49 through which heavy liquid flows out is formed in the lower part in the vertical direction. The mixer 44 mixes heavy and light liquids flowing into the mixing chamber 43a.

  And in the distribution apparatus 22, when the extractor 40 comprised as mentioned above is made into a multistage structure, the extractor 40 uses the light liquid inlet 46 for the light liquid of the extractor 40 adjacent to the water phase side. While connected to the outlet 48, the heavy liquid inlet 47 is connected to the heavy liquid outlet 49 of the extractor 40 adjacent to the organic phase side. Further, the extractor 40 connects its light liquid outlet 48 to the light liquid inlet 46 of the extractor 40 adjacent to the organic phase side, while its heavy liquid outlet 49 is adjacent to the aqueous phase side. Connected to the heavy liquid inlet 47 of the extractor 40.

  In the distributor 22 configured as described above, the U / Pu loaded solvent inlet 51 is provided in the first-stage extractor 40 on the water phase side among the extractors 40 arranged in multiple stages. The U / Pu loaded solvent is supplied from the decontamination device 21. The first stage extractor 40 is provided with a U-loaded solvent inlet 52 and supplied with the U-loaded solvent from the U / Pu back extraction device 24. On the other hand, in the distributor 22, among the extractors 40 arranged in multiple stages, the extractor 40 at the final stage on the organic phase side is provided with the back extract liquid inlet 53 and supplied with the Pu back extract liquid. The At this time, the U / Pu loading solvent and the U loading solvent become an organic phase, and the Pu back extract becomes an aqueous phase, so the U / Pu loading solvent and the U loading solvent become a light liquid, and the Pu back extract becomes a heavy liquid. It becomes.

  Then, the U / Pu loaded solvent, the U loaded solvent, and the Pu back-extracted liquid flow into the mixing chamber 43a of each extractor 40 of the distribution device 22. In the mixing chamber 43a of each extractor 40, when the mixer 44 mixes the U / Pu loaded solvent, the U loaded solvent, and the Pu back-extracted liquid, a part of the plutonium contained in the U / Pu loaded solvent is subjected to the Pu reverse. Transfer to extract. At this time, part of uranium contained in the U / Pu loaded solvent is also transferred to the Pu back-extracted solution. Thereafter, when the mixed U / Pu loading solvent, the U loading solvent, and the Pu back-extracted liquid flow into the separation chamber 43b, the U / Pu solution that is a Pu back-extracted liquid from which uranium and plutonium are back-extracted in the separation chamber 43b. And a U-loaded solvent that is a solvent after the back extraction of plutonium.

  Therefore, the U-loaded solvent flows out from the light liquid outlet 48 (U-loaded solvent outlet 54) of the most organic phase-side extractor 40 (final stage extractor) in the distributor 22. On the other hand, the U / Pu solution flows out from the heavy liquid outlet 49 of the extractor 40 (first-stage extractor) closest to the water phase in the distributor 22.

  The U / Pu extraction device 23 supplies an extraction solvent to the U / Pu solution supplied from the distribution device 22 to generate a U / Pu loaded solvent, and supplies a cleaning liquid to the U / Pu solution. The impurities contained in the / Pu solution are separated. That is, the U / Pu solution is separated in the U / Pu extraction apparatus 23 into a U / Pu loaded solvent and a cleaning liquid (waste liquid) containing impurities other than uranium and plutonium. The U / Pu extraction device 23 supplies the U / Pu loaded solvent to the U / Pu back extraction device 24, while discharging the cleaning liquid containing impurities as a waste liquid to a waste liquid receiving tank (not shown).

  The U / Pu back-extraction device 24 supplies the U / Pu solution, the U-loading solvent, and the U-Pu loading solvent supplied from the U / Pu extraction device 23 by supplying a Pu back-extraction solution as a back-extraction solution. To separate. The U / Pu back-extraction device 24 discharges the U / Pu solution as a U / Pu product solution, while supplying the U-loaded solvent toward the distribution device 22.

  Here, since the U / Pu reverse extraction device 24 has substantially the same configuration as the distribution device 22 shown in FIG. 4, the U / Pu reverse extraction device 24 will be described with reference to FIG. 4 and different from the distribution device 22. Reference numerals relating to the configuration of the extraction device 24 are shown in parentheses. In the U / Pu back extraction device 24, the description of the same configuration as the distribution device 22 is omitted.

  The U / Pu back extraction device 24 includes a plurality of extractors 40, a U / Pu loading solvent inlet 51 into which U / Pu loading solvent supplied from the U / Pu extraction device 23 flows, and a U into which U solution flows. A solution inlet (solution inlet) 62; a back extractant inlet 53 into which a Pu back extract for back-extracting plutonium flows; and a U loaded solvent outlet 54 from which a U loaded solvent flows out. Yes. At this time, the U / Pu loaded solvent inlet 51 and the U solution inlet 62 are provided in the first stage extractor 40, and the back-extraction liquid inlet 53 is provided in the final stage extractor 40. Yes.

  Therefore, in the U / Pu back extraction device 24, the U / Pu loaded solvent and the U solution are supplied to the first stage extractor 40, and the back extract is supplied to the final stage extractor 40. In the U / Pu back-extraction device 24, the U / Pu loading solvent is a U / Pu product solution that is a Pu back-extraction solution obtained by back-extracting uranium and plutonium, and a U-loading solvent that is a solvent after plutonium back-extraction. And to separate. Then, the U-loaded solvent flows out from the light liquid outlet 48 (U-loaded solvent outlet 54) of the extractor 40 (the final stage extractor) closest to the organic phase in the U / Pu back extraction device 24. On the other hand, the U / Pu product solution flows out from the heavy liquid outlet 49 of the extractor 40 (first-stage extractor) closest to the water phase in the U / Pu back extraction device 24.

  Here, the U-loaded solvent that has flowed out of the U / Pu back-extraction device 24 flows out toward the distribution device 22, and is supplied to the distribution device 22 via the U-loaded solvent inlet 52. In addition, the U / Pu back-extraction device 24 uses the U-loading solvent when the U-loaded solvent discharged from the U / Pu back-extraction device 24 is less than or equal to the uranium content used as a used solvent (for example, zero). It is not supplied to the distributor 22 but discharged as a used solvent.

  The first U back extraction device 25 separates the U solution and the used solvent by supplying a U back extract as a back extract to the U loaded solvent supplied from the distribution device 22. The first U back extraction device 25 supplies the U solution to the U extraction device 26 while discharging the used solvent.

  The U extraction device 26 supplies an extraction solvent to the U solution supplied from the first U back extraction device 25 to generate a U loaded solvent, and also supplies a cleaning liquid to the U solution, and impurities contained in the U solution. Isolate. That is, the U solution is separated by the U extraction device 26 into a U loading solvent and a cleaning liquid (waste liquid) containing impurities other than uranium. The U extraction device 26 supplies the U loading solvent to the second U back extraction device 27, while discharging the cleaning liquid containing impurities as a waste liquid to a waste liquid receiving tank (not shown).

  The second U back extraction device 27 is configured in substantially the same manner as the first U back extraction device 25, and supplies the U back extract as a back extract to the U loaded solvent supplied from the U extract device 26. Separate into solution and spent solvent. Then, the second U back extraction device 27 discharges the used solvent while discharging the U solution as the U product solution.

  As shown in FIGS. 2 and 3, the separation device 9 and the purification device 10 configured as described above include a plutonium enrichment degree (Pu richness) of the U / Pu solution discharged from the U / Pu back extraction device 24. In order to adjust the degree of conversion, a first flow rate adjustment valve 31, a second flow rate adjustment valve 32, a third flow rate adjustment valve 33, a tank 34, and a measuring device 35 are provided.

  The first flow rate adjustment valve 31 adjusts the flow rate of the U solution flowing into the U / Pu back extraction device 24 via the U solution inlet 62, and the U solution flows toward the U / Pu back extraction device 24. The U solution supply flow path L1 is provided. The first flow rate adjusting valve 31 is connected to the control device 13, and the flow rate of the U solution flowing through the U solution supply flow path L <b> 1 is adjusted by adjusting the opening degree by the control device 13.

  The second flow rate adjusting valve 32 adjusts the flow rate of the back extract liquid flowing into the U / Pu back extractor 24 via the back extract liquid inlet 53, and back-extracts toward the U / Pu back extractor 24. It is provided in the back-extraction liquid supply channel L2 through which the liquid flows. The second flow rate adjustment valve 32 is connected to the control device 13, and the flow rate of the back extract liquid flowing through the back extract solution supply flow path L <b> 2 is adjusted by adjusting the opening degree by the control device 13.

  The third flow rate adjusting valve 33 adjusts the flow rate of the U-loaded solvent flowing into the distribution device 22 via the U-loaded solvent inflow port 52, and the U-loaded solvent supply through which the U-loaded solvent flows toward the distribution device 22. It is provided in the flow path L3. The third flow rate adjusting valve 33 is connected to the control device 13, and the flow rate of the U loaded solvent flowing through the U loaded solvent supply flow path L <b> 3 is adjusted by adjusting the opening degree by the control device 13.

  The tank 34 is provided on the upstream side of the third flow rate adjusting valve 33 in the U loading solvent supply flow path L3, and stores the U loading solvent from the U / Pu back extraction device 24 and distributes the accumulated U loading solvent. Supply to the device 22 is possible.

  The measuring device 35 is provided in the U / Pu loading solvent supply flow path L <b> 4 through which the U / Pu loading solvent flows from the U / Pu extraction device 23 toward the U / Pu back extraction device 24. The measuring device 35 measures the contents of uranium and plutonium contained in the U / Pu loaded solvent, and measures the Pu enrichment of the U / Pu loaded solvent. The measuring device 35 is connected to the control device 13 and outputs the measurement result to the control device 13.

  The control device 13 controls the first flow rate adjustment valve 31, the second flow rate adjustment valve 32, and the third flow rate adjustment valve 33 based on the measurement result of the measurement device 35, thereby discharging from the U / Pu back extraction device 24. It is possible to adjust the Pu enrichment of the U / Pu product solution.

  Specifically, the control device 13 determines that the Pu enrichment degree of the U / Pu loaded solvent measured by the measurement device 35 is the target Pu enrichment of the U / Pu product solution discharged from the U / Pu back extraction device 24. It is determined that it is smaller than the set Pu enrichment level that is set to become a degree. In this case, the control device 13 controls the first flow rate adjustment valve 31 to the closed side so as to reduce the inflow amount of the U solution into the U / Pu back extraction device 24 or close the second flow rate adjustment valve 32. Control to the valve side to reduce the inflow amount of the back extract into the U / Pu back extractor 24, or control the third flow rate adjustment valve 33 to the valve open side to the U loading solvent distribution device 22. Increase the amount of inflow. Thereby, the control device 13 can increase the U / Pu product solution discharged from the U / Pu back extraction device 24 to a target Pu enrichment level.

  On the other hand, the control device 13 determines that the Pu enrichment degree of the U / Pu loaded solvent measured by the measurement device 35 is larger than the set Pu enrichment degree. In this case, the control device 13 controls the first flow rate adjustment valve 31 to the valve opening side to increase the inflow amount of the U solution into the U / Pu back extraction device 24 or open the second flow rate adjustment valve 32. Control to the valve side to increase the inflow amount of the back extract into the U / Pu back extractor 24 or control the third flow rate adjustment valve 33 to the valve close side to the U loading solvent distributor 22. To reduce the amount of inflow. Thereby, the control device 13 can reduce the U / Pu product solution discharged from the U / Pu back extraction device 24 to a target Pu enrichment level.

  For example, when the Pu content of the fuel solution measured by the measuring device 8 is 1%, the U / Pu back-extraction device 24 for plutonium in the U / Pu loaded solvent discharged from the U / Pu extraction device 23 By setting the ratio of the supplied U solution in the range of 0.0 to 10.1, the Pu enrichment degree of the U / Pu product solution discharged from the U / Pu back extraction device 24 is 85% to 33. % Can be adjusted within the range.

  On the other hand, when the Pu content of the fuel solution measured by the measuring device 8 is 30%, the U / Pu back extraction device 24 for plutonium in the U / Pu loaded solvent discharged from the U / Pu extraction device 23. By making the ratio of the U solution supplied to the range of 0.4 to 4.0, the Pu enrichment degree of the U / Pu product solution discharged from the U / Pu back extraction device 24 is 87% to It is possible to adjust within a range of 28%.

  For example, when the Pu content of the fuel solution measured by the measuring device 9 is 1%, the U / Pu back extraction device for plutonium in the U / Pu loaded solvent discharged from the U / Pu extraction device 23 The enrichment of Pu in the U / Pu product solution discharged from the U / Pu back-extraction device 24 by setting the ratio of nitric acid in the back-extraction solution supplied to 24 to a range of 0.6 to 0.1 Can be adjusted within a range of 32% to 70%.

  On the other hand, when the Pu content of the fuel solution measured by the measuring device 9 is 30%, the U / Pu back extraction device 24 for plutonium in the U / Pu loaded solvent discharged from the U / Pu extraction device 23. By making the ratio of nitric acid in the back extract supplied to the range of 3.8 to 0.4, the Pu enrichment degree of the U / Pu product solution discharged from the U / Pu back extractor 24 is , 33% to 57% can be adjusted.

  As described above, according to the present embodiment, even when spent fuel with a high Pu content is reprocessed, the U / Pu reverse extraction device 24 allows the U solution to flow into the U / Pu reverse extractor 24. Since uranium can be mixed with the solution flowing out from the extraction device 24, the U / Pu product solution can be purified without isolating plutonium. In addition, the U solution is caused to flow into the U / Pu back extraction device 24, and the U loaded solvent that has flowed out from the U / Pu back extraction device 24 is caused to flow into the distribution device 22, thereby containing uranium contained in the U / Pu solution. Since the amount can be adjusted, it is possible to freely adjust the Pu enrichment of the purified U / Pu product solution. In this way, even when the Pu content of the spent fuel to be received varies, the amount of U solution flowing into the U / Pu back extraction device 24 is adjusted, or the back extract liquid U / Pu back extraction device is adjusted. By adjusting the inflow amount to 24 or adjusting the inflow amount of the U-loaded solvent to the distribution device 22, it is possible to purify the U / Pu product solution that achieves the required Pu enrichment level. Therefore, it can be set as the highly versatile reprocessing facility 1 which can respond flexibly to fluctuations in Pu content and fluctuations in Pu enrichment.

  In addition, according to the present embodiment, the control device 13 uses the U solution based on the Pu content contained in the U / Pu loaded solvent flowing from the U / Pu extraction device 23 to the U / Pu back extraction device 24. The amount of inflow to the U / Pu back extraction device 24 is adjusted, the amount of inflow of the back extract to the U / Pu back extraction device 24 is adjusted, and the amount of inflow of the U-loaded solvent to the distribution device 22 is adjusted. You can do it. For this reason, the control device 13 accurately adjusts the flow rates of the U solution, the back-extracted solution, the U-loaded solvent, etc. so that the Pu enrichment of the U / Pu product solution to be purified becomes the required Pu enrichment. It can be adjusted well.

  Further, according to the present embodiment, the control device 13 adjusts at least one of the first flow rate adjustment valve 31, the second flow rate adjustment valve 32, and the third flow rate adjustment valve 33 based on the measurement result of the measurement device 35. By controlling the valve, the Pu enrichment of the U / Pu product solution can be accurately adjusted.

  In addition, according to the present embodiment, the U-loaded solvent that has flowed out of the U / Pu back extraction device 24 can be temporarily stored in the tank 34, and the predetermined flow rate from the tank 34 toward the distribution device 22 can be obtained. The U-loaded solvent can be dispensed.

  Further, according to the present embodiment, when the uranium content contained in the U loaded solvent flowing out from the U / Pu back extraction device 24 is almost zero, the U / Pu back extraction device 24 discharges it as a used solvent. Can do.

  In the present embodiment, the U solution supplied to the U / Pu back extraction device 24 is not particularly limited. For example, the U solution discharged from the first U back extraction device 25 may be used.

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 Denitration apparatus 12 Fuel production apparatus 13 Control apparatus 21 Co-decontamination apparatus 22 Distribution apparatus 23 U / Pu extraction apparatus 24 U / Pu reverse extraction device 25 1U reverse extraction device 26 U extraction device 27 2U reverse extraction device 31 1st flow rate adjustment valve 32 2nd flow rate adjustment valve 33 3rd flow rate adjustment valve 34 Tank 35 Measuring device 40 Extractor 43 Container 44 Mixer 46 Light liquid inlet 47 Heavy liquid inlet 48 Light liquid outlet 49 Heavy liquid outlet 51 U / Pu loaded solvent inlet 52 U loaded solvent inlet 53 Back extraction liquid inlet 62 U solution inlet L1 U solution supply Flow path L2 Back extract liquid supply flow path L3 U loaded solvent supply flow path L4 U / Pu loaded solvent supply flow path

Claims (5)

A reprocessing facility that separates and reprocesses uranium and plutonium from multiple types of spent fuel with different plutonium content,
First uranium / plutonium loading solvent flows that are co-decontamination co decontamination apparatus, the inflow of the first uranium / plutonium loading solvent by back-extracted with stripping solution, the uranium / plutonium solution and uranium A dispensing device for dispensing with the loading solvent;
The uranium / plutonium solution distributed by the distribution device flows in, and the extracted uranium / plutonium solution is extracted with a solvent, thereby generating a second uranium / plutonium loaded solvent; and
The second uranium / plutonium loaded solvent generated by the extraction device flows in, and the second uranium / plutonium loaded solvent that has flowed in is back-extracted with a back extraction solution, whereby the uranium / plutonium solution and the uranium are A back extraction device for distributing to the loading solvent,
The back extraction device comprises:
A loading solvent inlet through which the second uranium / plutonium loading solvent flows from the extraction device;
A solution inlet into which the uranium solution flows,
A back extract inlet into which the back extract flows,
A reprocessing facility comprising: a loaded solvent outlet through which the dispensed uranium loaded solvent flows out toward the distributor. A measuring device for measuring the uranium content and the plutonium content contained in the second uranium / plutonium loaded solvent flowing from the extraction device toward the back extraction device;
The reprocessing facility according to claim 1, further comprising a control device that performs control based on a result of the measurement device. A first flow rate adjustment valve for adjusting a flow rate of the uranium solution flowing into the back extraction device via the solution inlet;
A second flow rate adjustment valve that adjusts the flow rate of the back-extracted liquid flowing into the back-extraction device through the back-extracted liquid inlet;
At least one flow rate adjustment valve among the third flow rate adjustment valve that adjusts the flow rate of the uranium loading solvent flowing out toward the distribution device via the loading solvent outlet port,
The reprocessing facility according to claim 2, wherein the control device controls the flow rate adjusting valve based on a result of the measurement device.   In the flow direction of the uranium loading solvent flowing from the back-extraction device to the distribution device, the tank further includes a tank provided upstream of the third flow rate adjustment valve and storing the uranium loading solvent. The reprocessing facility according to claim 3.   When the uranium content contained in the uranium loaded solvent flowing out from the back extraction device through the loaded solvent outlet is less than or equal to the uranium content used as the used solvent, the uranium loaded solvent is used as the used uranium loaded solvent. The reprocessing facility according to any one of claims 1 to 4, wherein the reprocessing facility is discharged as a solvent.

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