JP2013224925A - Method and system for treating spent fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and system for treating spent fuel which reduce the burden on a thermal neutron reactor 1 which stores thermal neutron reactor spent fuel 2, which is an emergent and important problem, and also achieve safe cool storage.SOLUTION: A method for treating spent fuel 2 discharged from a thermal neutron reactor power plant 1 includes mixing separated high level radioactive waste with extracted plutonium and part of uranium, and cooling and storing them in a renewable manner.

Description

  The present invention relates to a spent fuel processing method and a processing system for reducing the burden of cooling and storing spent fuel in a thermal neutron reactor when the nuclear power plant is mainly used for thermal neutron reactor power generation, for example, light water reactor power generation. About.

  The conventional fuel cycle system for thermal neutron reactor power generation has a mechanism for reprocessing spent fuel generated from a thermal neutron reactor power plant in a thermal neutron reactor reprocessing facility. Specifically, it separates and recovers uranium and plutonium from spent fuel to produce fuel for thermal neutron reactors, and at the same time vitrifies high-level radioactive waste generated from fission products and stores them in a cold state. (For example, refer nonpatent literature 1 and patent literature 1).

"All about nuclear power" Editorial Board, "All about nuclear power", National Printing Bureau JP 2006-275638 A

  In a standard light water reactor cycle system at the time of nuclear power generation by a thermal neutron reactor, plutonium obtained by reprocessing spent fuel in the thermal neutron reactor is processed into MOX fuel. Thereafter, the MOX fuel is used for generating electricity in a thermal neutron reactor, so-called pull thermal, so that plutonium is burned and consumed.

However, there is a possibility that this use of pull thermal may not be performed as planned. In this case, it is necessary to partially stop the operation of the reprocessing facility because it is not possible to store the surplus plutonium MOX fuel that is not used.
Moreover, even if the execution of the use of the pull thermal is performed as planned, for example, if a failure occurs in the vitrification facility, the reprocessing facility cannot be operated.

  As described above, there is a problem that the amount of spent fuel stored in the thermal neutron reactor continues to increase when the light water reactor spent fuel cannot be reprocessed or when the operating rate of operation decreases. For this reason, there are demands for measures for reducing the burden and safe cooling storage for storing spent fuel.

  For example, a forced circulation system of cooling water using a power source is employed for conventional cold storage of spent fuel. In the case of this spent fuel cooling storage system, the cooling function is lost when the entire power source is lost due to the occurrence of an earthquake or tsunami. Thus, the heat generated from the spent fuel heats and raises the temperature of the cladding tube zirconium alloy of the spent fuel. Therefore, if such a state continues for a long time, hydrogen is generated by the reaction between the cladding tube zirconium alloy and water at a high temperature, and there is a risk of eventually causing a hydrogen explosion.

  Thus, for the storage of LWR spent fuel, it is an urgent and important issue to reduce the burden and ensure safety.

  The present invention has been made on the basis of the above-described matters, and an object of the present invention is to reduce the burden of storing spent fuel in a thermal neutron reactor and to achieve a safe cold storage and a spent fuel processing method. A processing system is provided.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-mentioned problems. For example, in the method for treating spent fuel discharged from a thermal neutron reactor power plant, separated high-level radioactive waste, The extracted plutonium and a part of uranium are mixed and stored in a recyclable form in a cold storage.

  According to the present invention, the amount of spent fuel can be reduced by mixing / storage of high-level radioactive waste separated from spent fuel, and extracted plutonium and a part of uranium, thereby greatly reducing the quantity. Therefore, the burden of storage management can be reduced. Moreover, since it cools and stores by the natural circulation air cooling method, the accident potential regarding cooling safety can be reduced and high safety | security can be ensured.

  Further, in the case where the use of the pluthermal is performed as planned, even if a failure or the like occurs in the vitrification facility, according to the present invention, the high-level radioactive waste separated from the spent fuel is isolated. Or by mixing it with a part of the extracted uranium and maintaining the operating rate of the reprocessing equipment, reducing the burden of storage management of spent fuel, and ensuring high safety it can.

It is a flowchart which shows the process process of the thermal neutron reactor cycle system to which 1st Embodiment of the processing method and processing system of the spent fuel of this invention are applied. It is a flowchart which shows the process of the fast neutron reactor cycle system as an example compared with 1st Embodiment of the processing method and processing system of the spent fuel of this invention. It is a partial longitudinal cross-sectional view which shows an example of the storage facility of the volume reduction fuel body or waste body which comprises 1st Embodiment of the processing method and processing system of the spent fuel of this invention. It is a perspective view which shows the canister which stores the volume reduction fuel body or waste body which comprises 1st Embodiment of the processing method and processing system of the spent fuel of this invention. It is a longitudinal cross-sectional view which shows the storage aspect of the volume reduction fuel body or waste body which comprises 1st Embodiment of the processing method and processing system of the spent fuel of this invention. It is a flowchart which shows the aspect which applies the 2nd Embodiment of the processing method and processing system of the spent fuel of this invention to the existing light water reactor reprocessing equipment about the case where pull thermal utilization is not performed. It is a conceptual diagram which shows the manufacturing process of the volume reduction fuel body in 2nd Embodiment of the processing method and processing system of the spent fuel of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to these embodiments.

FIG. 1 is a flowchart showing the processing steps of a thermal neutron reactor cycle system to which a first embodiment of the spent fuel processing method and processing system of the present invention is applied.
In FIG. 1, the fuel cycle system includes a thermal neutron reactor 1, a thermal neutron reactor reprocessing facility 3, a recovery uranium storage facility 4, a MOX fuel processing facility 5, a thermal neutron reactor 6 that performs pull thermal, a vitrification facility 7, and a vitrified body. The storage facility 9, the radioactive waste disposal site 10, the granulation facility 20, the volume reduction fuel body or waste body 21, and the volume reduction fuel body or waste storage facility 22. The difference from the conventional standard light water reactor fuel cycle system is that a granulation facility 20, a volume reduction fuel body or waste body 21, and a volume reduction fuel body or waste body storage facility 22 are newly provided. . In addition, the arrow a on the figure indicates the movement of uranium, the arrow b indicates the movement of fission products (hereinafter referred to as FP) and minor actinoid MA, which are high-level radioactive waste, and the arrow c indicates plutonium and uranium. The d arrow represents the movement of plutonium, uranium, and high-level radioactive waste, respectively. When pluthermal use is performed, the arrow d indicates the movement of high-level radioactive waste alone or mixed with a part of the extracted uranium, 21 is waste, 22 is waste It becomes a body storage facility.

  The feature of the first embodiment of the present invention is that, even if the cycle from the thermal neutron reactor reprocessing facility 3 to the MOX fuel processing facility 5 cannot be performed, the granulation facility 20, the volume-reduced fuel body, or the disposal By executing the cycle to the storage facility 22 for the body 21, the volume-reduced fuel body or the waste body, the burden of storing the spent fuel of the thermal neutron reactor is reduced and safe cooling storage is achieved. In other words, from the thermal neutron reactor reprocessing facility 3 to the MOX fuel processing facility 5 or the granulation facility 20, the plutonium obtained from the thermal neutron reactor spent fuel 2, high-level radioactive waste, and recovery It constitutes a fuel cycle system that can pay out part of uranium.

  Further, even when a cycle from the thermal neutron reactor reprocessing facility 3 to the MOX fuel processing facility 5 can be executed and a defect or the like occurs in the vitrification facility, the granulation facility 20, the volume-reducing fuel The cycle to the body or waste body 21, the reduced volume fuel or waste storage facility 22 can be performed.

  The thermal neutron reactor spent fuel 2 dispensed from the thermal neutron reactor 1 is separated and reduced in volume through the thermal neutron reactor reprocessing facility 3 and the granulation facility 20. The separated uranium is recovered and stored in the recovered uranium storage facility 4.

  In the thermal neutron reactor reprocessing facility 3, plutonium obtained from the thermal neutron reactor spent fuel 2 and a part of the recovered uranium are sent to the MOX fuel processing facility 5.

  The plutonium MOX fuel has a higher plutonium ratio than the thermal neutron reactor spent fuel 2. However, the plutonium content of the thermal neutron reactor spent fuel 2 varies depending on the fuel specifications depending on the combustion conditions and initial conditions. Moreover, the plutonium content of the MOX fuel for pull thermal differs depending on the specifications such as the combustion conditions of the fuel. Therefore, in the thermal neutron reactor reprocessing facility 3, an arbitrary amount of recovered uranium is added to plutonium obtained from the thermal neutron reactor spent fuel 2 and sent to the MOX fuel processing facility 5. As a result, it is possible to obtain a plutonium-enriched fuel required in the thermal neutron furnace 6 that performs the pull thermal operation.

  The vitrification facility 7 mixes and fixes the fission product FP and the minor actinoid MA, which are high-level radioactive waste obtained in the thermal neutron reactor reprocessing facility 3, with glass melted to produce a vitrified body 8. To do. The vitrified body 8 is stored in the vitrified body storage facility 9 for an intermediate period of, for example, about 50 years, waits for the radioactive material to decrease and the temperature to drop, and is finally disposed of at the radioactive waste disposal site 10.

  The granulation facility 20 mixes plutonium obtained in the thermal neutron reactor reprocessing facility 3, high-level radioactive waste, and a part of the recovered uranium in a solution state, and performs drying or the like to reduce the volume of the fuel body composed of granules. Alternatively, it is a facility for generating the waste body 21. The volume-reduced fuel body or waste body 21 is stored in the storage facility 22 for volume-reduced fuel body or waste body, for example, for about 50 years.

The composition ratio of plutonium, uranium, and high-level radioactive waste in the volume-reduced fuel body or waste body 21 is determined as follows.
First, when the pluthermal use is not performed, all the high-level waste and plutonium obtained by the thermal neutron reactor reprocessing facility 3 are sent to the granulation facility 20. Further, in the thermal neutron reactor reprocessing facility 3, a part of uranium is taken out and sent to the granulation facility 20 so as to become a constituent material of the volume-reduced fuel body 21. The remaining uranium in the thermal neutron reactor reprocessing facility 3 is purified and recovered / utilized as recovered uranium. Here, the percentage of uranium contained in the volume-reduced fuel body 21 is set to 30% or more in consideration of critical safety. Next, if a pull thermal application is performed, high level radioactive waste and a portion of uranium are sent to the granulation facility 20.

  The volume-reduced fuel body or waste body 21 is sent to the volume-reduced fuel body or waste body storage facility 22 and temporarily stored. The storage period is about 50 years, and after storage, it is processed into fuel for fast neutron reactors or is subjected to geological disposal such as vitrification. Therefore, it is desirable that the volume-reduced fuel body 21 be processed in the same process as the spent fuel of the fast neutron reactor in the fast neutron reactor fuel reprocessing facility.

  In addition to plutonium and uranium, this reduced spent fuel contains fission products contained in the spent fuel of fast neutron reactors and transuranium elements other than plutonium such as neptunium Np, americium Am, and curium Cm. You can leave.

  As a treatment method for removing most of uranium from the thermal neutron reactor spent fuel 2 and cooling and storing the spent fuel after volume reduction, for example, there is a method described in Patent Document 1. FIG. 2 is a flowchart showing the processing steps of the fast neutron reactor transition cycle system as an example compared with the first embodiment of the spent fuel processing method and processing system of the present invention. In FIG. 2, the same reference numerals as those shown in FIG.

  The fast neutron reactor transition cycle system in FIG. 2 is for the transition period from a thermal neutron reactor to a fast neutron reactor, and includes a thermal neutron reactor 1, a volume reduction treatment facility 25, a recovery uranium storage facility 4, a fast neutron reactor. It comprises a fuel reprocessing facility 26, a fast neutron reactor MOX fuel processing facility 27, a fast neutron reactor 28, a vitrification facility 7, a vitrified body 8, a vitrified body storage facility 9, and a radioactive waste disposal site 10.

  The thermal neutron reactor spent fuel 2 dispensed from the thermal neutron reactor 1 is separated and reduced in volume reduction treatment facility 25 by separating most of the uranium. This reduced spent fuel is temporarily stored. The temporarily stored volume-reduced spent fuel is processed in the fast neutron reactor fuel reprocessing facility 26 according to the state of the fast neutron reactor 28, and passes through the fast neutron reactor MOX fuel processing facility 27 to the fast neutron reactor 28. Supplied and recycled.

  In order to solve the problem of the present invention, instead of the fast neutron reactor 28 of the fast neutron reactor transition cycle system described above, a thermal neutron reactor 6 for pull thermal implementation is arranged to constitute a spent fuel cycle system. Seems to be an effective means.

  However, the fast neutron reactor fuel reprocessing facility 26 treats materials having concentrations of plutonium and high-level radioactive waste that are at least as high as the spent fuel in the fast neutron reactor 28. There are many technical problems regarding the reprocessing technology of fuel containing such highly enriched plutonium and high concentration radioactive waste. In addition, there are many problems to be solved such as critical safety management and shielding, and there is a concern about an increase in manufacturing cost of equipment from these viewpoints.

  Therefore, it is difficult to apply the method described in Patent Literature 1 as a thermal neutron reactor cycle reprocessing method, which is disadvantageous from the viewpoint of economy.

Next, the granulation facility 20 and the volume-reducing fuel body or waste body 21 in the present embodiment will be described.
As described above, the volume reduction fuel body or waste body 21 needs to be reprocessable again in the fast neutron reactor fuel reprocessing facility after temporary storage in the volume reduction fuel body or waste body storage facility 22. . For this reason, the volume-reduced fuel body or waste body 21 needs to be stored in a recyclable form. Renewable storage forms include solution form or granule form, but the solution form is not suitable because the storage period is about 50 years. Further, storing as a vitrified material is inappropriate because it becomes extremely difficult to regenerate. For this reason, in this Embodiment, the volume reduction fuel body or the waste body 21 is made into the form of a granule.
In addition, a granule can be heat-processed and it can be set as a granule sintered body (granular sintering). In this case, although the number of processing steps is increased, advantages such as improved thermal conductivity can be obtained.

Further, in the fuel cycle system according to the present embodiment, when the thermal power of the thermal neutron reactor spent fuel 2 is used, the following three treatments can be selected as the treatment of the high-level radioactive waste.
(1) Vitrification (2) Single granulation or granulation sintering (3) Granulation or granulation with some extracted uranium In the future, vitrification technology is established and applicable In that case, (1) selection of vitrification is possible. As shown in FIG. 1, the vitrified body 8 is intermediately stored in a vitrified body storage facility 9, for example, for about 50 years, and then finally disposed at a radioactive waste disposal site 10. Considering the technological progress of these 50 years, even if vitrification is possible, it is possible to regenerate (2) single granulation or granulation or (3) with some extracted uranium It is desirable to select granulation or granulation sintering.

  Renewable (2) Single granulation or granulation or (3) Granulation or granulation with some extracted uranium and storing as waste, final after 50 years It is because it becomes possible to perform more rational disposal reflecting the latest vitrification technology developed after 50 years before disposal. For example, it is predicted that the amount of waste can be reduced by adopting a high volume reduced glass solidified body. In addition, it is predicted that environmental load reduction will be achieved by adopting the separation and conversion technology for highly harmful minor actinoids.

  In this way, by granulating high-level radioactive waste, for example, it can be stored and stored safely with low burden for 50 years, so that the latest vitrification technology and waste treatment and disposal technology developed 50 years later can be used. Final disposal after application is possible.

  By the way, as a technique for producing a granule, there is a rotary kiln method which has already been put into practical use in France and the like. Another granule production method is a freeze vacuum drying method. The latter is a technology that is widely used in industry, although it has no track record in the field of nuclear power, and has the advantage of reducing the scattering of high-level radioactive waste and controlling the particle size of granules.

  Next, the storage facility 22 for volume-reducing fuel bodies or waste bodies in the present embodiment will be described with reference to the drawings. FIG. 3 is a partial longitudinal sectional view showing an example of a storage facility for a volume-reduced fuel body or a waste body constituting the first embodiment of the spent fuel processing method and processing system of the present invention, and FIG. 4 shows the present invention. FIG. 5 is a perspective view showing a canister for storing a volume-reduced fuel body or a waste body constituting the first embodiment of the spent fuel treatment method and treatment system of the present invention, and FIG. 5 is a spent fuel treatment method and treatment according to the present invention. It is a longitudinal cross-sectional view which shows the storage aspect of the volume reduction fuel body or waste body which comprises 1st Embodiment of a system. 3 to 5, the same reference numerals as those shown in FIGS. 1 and 2 are the same parts, and detailed description thereof is omitted.

  In FIG. 3, the storage facility 22 for the volume-reducing fuel body or waste body is made of, for example, a semi-underground concrete structure, and is roughly a cooling air introduction part 41 and a canister that houses the volume-reducing fuel body or waste body 21. A storage area 42 for storing the storage pipe 31 in which 30 is stacked and stored, and a cooling air discharge unit 43 are provided.

  The cooling air introduction part 41 includes an intake port 41A for taking in the cooling air A from the atmosphere, and a ventilation part 41B. The cooling air A taken from the air inlet 41A is introduced into the lower portion of the storage area 42 through the ventilation portion 41B provided in the underground direction.

  The storage area 42 is formed in a substantially box shape having a space inside, and the bottom portion is formed by the lower support mechanism 42A and the upper portion is formed by the ceiling slab 42B, and between the lower support mechanism 42A and the ceiling slab 42B. A support mechanism 42C is provided. The cooling air A is introduced from the lower support mechanism 42 </ b> A, moves upward while cooling the volume-reduced fuel body or waste body 21, and is discharged from the cooling air discharge unit 43.

  The cooling air discharge portion 43 includes a ventilation portion 43B that guides the cooling air A discharged from the storage area 42 upward, and a discharge port 43A that discharges the cooling air A to the outside air.

  As shown in FIG. 4, the volume-reduced fuel body or waste body 21 is housed in a canister 30 having a right cylindrical shape made of a material that does not generate hydrogen, such as stainless steel, together with air or helium gas.

  As shown in FIG. 5, the canister 30 is stacked and stored in the storage pipe 31. A ventilation pipe 32 having a diameter larger than that of the storage pipe 31 is provided on the outer periphery of the storage pipe 31. The cooling air A passes through the gap between the storage pipe 31 and the ventilation pipe 32 and naturally cools the volume-reduced fuel body or waste body 21 in the storage pipe 31. The bottom of the storage tube 31 is supported by the lower support mechanism 42A, and the top thereof is supported by the ceiling slab 42C. The lower part of the ventilation pipe 32 is supported by the lower support mechanism 42A, and the substantially middle part of the ventilation pipe 32 is supported by the support mechanism 42B.

  According to the first embodiment of the spent fuel processing method and processing system of the present invention described above, high-level radioactive waste separated from the thermal neutron reactor spent fuel 2, extracted plutonium and a part thereof By mixing / storage uranium, the volume of the spent neutron reactor spent fuel 2 can be reduced and the amount of material can be greatly reduced, so the burden of storage management can be reduced. Moreover, since it cools and stores by the natural circulation air cooling method, the accident potential regarding cooling safety can be reduced and high safety | security can be ensured.

  In addition, according to the first embodiment of the spent fuel processing method and processing system of the present invention described above, the thermal neutron reactor reprocessing facility 3 for the spent thermal neutron reactor fuel 2 can be operated at the scale and timing of the pull thermal. It is possible to operate without relying on it, and it is possible to gain experience and achievements in reprocessing technology. Thereby, the reliability regarding a reprocessing technique can be improved. In order to realize sustainable use of nuclear power, it is necessary to establish reprocessing technology for spent fuel and to recycle fuel containing plutonium using a fast neutron reactor, but both reprocessing technology and fast neutron reactor technology have many development issues. There is concern that the introduction of this at the same time is accompanied by a significant risk. According to this embodiment, since the reliability of the reprocessing technology can be established first, the reliability of sustainable nuclear power use by the fast neutron reactor can be greatly improved. This contributes to fostering a sense of social security and can increase its feasibility.

  Furthermore, according to the first embodiment of the spent fuel processing method and processing system of the present invention described above, since the reduced spent fuel is made into granules, the volume-reduced fuel body 21 is regenerated. Can do. After cold storage, it can be reused as fuel material for fast neutron reactors.

  Further, according to the above-described first embodiment of the spent fuel processing method and processing system of the present invention, when using pluthermal, a high volume reduced glass solidified body is adopted to reduce the amount of waste. In addition, by adopting the separation and conversion technology of minor actinoids, it is possible to reduce the degree of harm and to reduce the environmental load in waste disposal.

  Furthermore, according to the first embodiment of the spent fuel processing method and the processing system of the present invention described above, only the high-level radioactive waste separated from the thermal neutron reactor spent fuel 2 is granulated and stored in a cooled state. Therefore, by extracting plutonium and uranium and processing the MOX fuel, it is possible to use pluthermal and reduce the burden of spent thermal neutron reactor spent fuel 2 without lowering the operating rate of the thermal neutron reactor reprocessing facility 3. Safety can be achieved.

  The second embodiment of the spent fuel processing method and processing system of the present invention will be described below with reference to the drawings. FIG. 6 is a flow chart showing a mode in which the second embodiment of the spent fuel treatment method and treatment system of the present invention is applied to an existing light water reactor reprocessing facility when pull thermal is not used, and FIG. It is a conceptual diagram which shows the manufacturing process of the volume reduction fuel body in 2nd Embodiment of the processing method and processing system of the spent fuel of this invention. 6 and 7, the same reference numerals as those shown in FIGS. 1 to 5 are the same parts, and the detailed description thereof will be omitted.

FIG. 6 shows a mode in which the present invention is backfitted to the processing flow when the PUREX method reprocessing technology is adopted in the thermal neutron reactor reprocessing facility 3 in FIG.
First, an outline of the PUREX method reprocessing technique will be described. In FIG. 6, the thermal neutron reactor spent fuel 2 dispensed from the thermal neutron reactor 1 is cut into, for example, several centimeters long by a shearing machine 50A. The sheared pieces of the cut thermal neutron reactor spent fuel 2 are dissolved in the dissolution tank 50B, and the dissolved liquid containing the dissolved plutonium, uranium, and high-level radioactive waste (FP / MA) becomes the next high level. Proceed to the radioactive waste (FP / MA) separation step 51. The residue that has not been dissolved in the dissolution tank 50B is stored in the storage 50C or the like.

  In the high-level radioactive waste (FP / MA) separation step 51, the solution containing uranium and plutonium and the solution containing FP / MA are separated from the solution containing the high-level radioactive waste (FP / MA). . The extracted solution containing uranium and plutonium is sent to the uranium / plutonium separation step 52, and the solution containing FP / MA is sent to the vitrification facility 7.

  In the uranium / plutonium separation step 52, uranium and plutonium are separated from each other. The separated solution containing uranium is sent to the uranium purification step 53, and the separated solution containing plutonium is sent to the plutonium purification step 54.

  In the uranium purification step 53 and the plutonium purification step 54, uranium and plutonium are purified, respectively. In the separation steps 51 and 52 and the purification steps 53 and 54, since an aqueous nitric acid solution is obtained, for example, oxides (UO2 and PuO2 + UO2) are generated through the uranium denitration step 55 and the mixed (plutonium + uranium) denitration step 56, These products are stored in the respective storages 57 and 58.

  In the second embodiment of the present invention, the following remodeling and additional installation are performed in the thermal neutron furnace reprocessing facility 3 of the above-described PUREX method reprocessing technology. As an additional installation, as shown in FIG. 6, a pipe that sends the solution containing the high-level radioactive waste (FP / MA) separated in the high-level radioactive waste (FP / MA) separation step 51 to the granulation facility 20. <3>, piping <2> for sending the uranium-containing solution separated in the uranium / plutonium separation step 52 to the granulation facility 20, and the granulation facility for the solution containing plutonium separated in the uranium / plutonium separation step 52 Pipe <1> to be sent to 20 is additionally installed. A granulation facility 20 will be additionally installed. As the modification, the volume-reduced fuel body 21 from the granulation facility 20 can be stored by remodeling the vitrified body storage facility 9.

  As described above, the present embodiment includes a solution containing high-level radioactive waste (FP / MA) separated from an existing light water reactor cycle system, a solution containing separated and unpurified plutonium, and a separated and unpurified solution. The granules containing uranium are dried / denitrated to produce granules, filled in the canister 30, and cooled and stored in the storage facility 22 for reducing the volume of fuel.

  Granules obtained from a solution obtained by mixing all the FP, plutonium and a part of uranium in the thermal neutron reactor spent fuel 2 become a volume-reduced fuel in which most of the uranium is separated / recovered.

  In FIG. 6, a solution containing separated plutonium and a solution containing separated uranium mixed with a solution containing high-level radioactive waste (FP / MA) separated for an existing light water reactor cycle system are: A solution after purification can be used instead of the solution before purification described above, and can be determined in consideration of the addition of actual equipment or the ease of modification.

  FIG. 7 shows a conceptual diagram of a process for producing a volume-reduced fuel body when the rotary kiln method is used as a technique for producing granules.

  The storage facility of the granulated volume-reduced fuel body 21 in the canister 30 can be cooled and stored with high safety by the natural circulation air cooling method, but the existing vitrified body storage facility 9 can also be shared. it can.

  Since the vitrification facility 7 needs to be updated, the granulation facility 20 can be replaced with a vitrified body production facility according to the implementation status of the pull thermal. Further, the vitrified body storage facility 9 is expanded in accordance with the amount of vitrified body 8 produced. Therefore, even if the granular storage of the volume-reduced fuel body 21 is employed, the volume-reduced fuel body storage facility 22 can be provided with almost the same installation location and equipment cost as the equipment necessary for storing the vitrified body 8. it can.

  According to the second embodiment of the spent fuel processing method and processing system of the present invention described above, the same effects as those of the first embodiment described above can be obtained.

  In addition, according to the second embodiment of the spent fuel processing method and processing system of the present invention described above, if the granulation facility 20 is provided in the existing light water reactor reprocessing facility, it is generated in the granulation facility 20. Since the volume-reduced fuel body 21 can be stored by modifying the existing vitrified body storage facility 9, equipment for reducing the burden of storing spent fuel can be installed at low cost.

DESCRIPTION OF SYMBOLS 1 Thermal neutron reactor 2 Thermal neutron reactor spent fuel 3 Thermal neutron reactor reprocessing facility 4 Recovered uranium storage facility 5 MOX fuel processing facility 6 Thermal neutron reactor 7 of the pre-thermal implementation Vitrification facility 8 Vitrification body 9 Vitrification body storage facility 10 Radioactive waste disposal site 20 Granulation facility 21 Volume reduction fuel body or waste body 22 Volume reduction fuel body or waste storage facility 25 Volume reduction treatment facility 26 Reprocessing facility for fast neutron reactor fuel 27 MOX fuel for fast neutron reactor Processing facility 28 Fast neutron reactor 30 Canister 31 Storage tube 32 Ventilation tube

Claims (18)

In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is mixed with the extracted plutonium and a part of uranium, and is cooled and stored in a recyclable form. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is mixed with the extracted plutonium and some uranium and stored as granules. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, comprising mixing separated high-level radioactive waste, extracted plutonium, and a portion of uranium, and storing the mixture as a granular sintered body. The spent fuel discharged from the thermal neutron reactor power plant is processed by the PUREX method, and the separated high-level radioactive waste is mixed with the extracted plutonium and some uranium in a recyclable form. A method for treating spent fuel, characterized by storing in a cold state. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
It is characterized by mixing the separated high-level radioactive waste with the extracted plutonium and some uranium and storing the renewable volume-reduced spent fuel produced by the rotary kiln method or freeze-vacuum drying method. How to dispose of spent fuel. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is mixed with the extracted plutonium and some uranium and stored by a cooling method that does not use a power source or the like. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
Processing of spent fuel, characterized by mixing the separated high-level radioactive waste with the extracted plutonium and some uranium and cooling them in a natural circulation air cooling system in a recyclable form Method. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
Spent fuel characterized by mixing the separated high-level radioactive waste with the extracted plutonium and some uranium, filling the canister with air or helium gas in a recyclable form, and cooling and storing it Processing method. A processing system for spent fuel discharged from a thermal neutron reactor power plant,
A granulation facility for mixing the separated high-level radioactive waste with the extracted plutonium and a part of uranium in a solution state and drying / denitrating it to produce a volume-reduced fuel body composed of granules; A spent fuel processing system comprising: a reduced volume fuel storage facility for temporarily storing a reduced volume fuel body from the granulation facility. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is singly or mixed with a part of the extracted uranium and stored in a refrigerated form. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is singly or mixed with a part of the extracted uranium and stored as granules. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is singly or mixed with a part of the extracted uranium and stored as a granular sintered body. Spent fuel discharged from a thermal neutron reactor power plant is processed by the PUREX method, and the separated high-level radioactive waste can be used alone or mixed with a part of the extracted uranium in a recyclable form A method for treating spent fuel, characterized by storing in a cold state. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
Spent fuel characterized in that the separated high-level radioactive waste is singly or mixed with a part of the extracted uranium and is produced by the rotary kiln method or freeze-drying method and stored in a recyclable form Processing method. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
A method for treating spent fuel, characterized in that the separated high-level radioactive waste is stored alone or mixed with a part of the extracted uranium and stored by a cooling method that does not use a power source or the like. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
Treatment of spent fuel characterized by cooling and storing the separated high-level radioactive waste alone or mixed with a part of the extracted uranium and using a natural circulation air cooling system in a recyclable form Method. In a method for treating spent fuel discharged from a thermal neutron reactor power plant,
Spent fuel characterized in that the separated high-level radioactive waste is stored alone or in a reusable form mixed with a portion of the extracted uranium and filled in a canister with air or helium gas and stored cold. Processing method. A processing system for spent fuel discharged from a thermal neutron reactor power plant,
A granulation facility for mixing the separated high-level radioactive waste alone or a part of the extracted uranium in a solution state and drying / denitrating the mixture to produce a waste body comprising the granules, and the granules A spent fuel processing system comprising: a waste storage facility for temporarily storing waste from a wastewater treatment facility.

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