Method for Producing Transuranium Isotopes Using a Sodium-Cooled Fast Reactor, Sodium-Cooled Fast Reactor Core

Abstract

This application belongs to the technical field of sodium-cooled fast reactor for isotope production, aiming to solve the problems of limited moderation effect, large core perturbation, and unfavorable fast neutron energy spectrum for the production of transuranic isotopes during the production of transuranic isotopes. This application provides a method for producing transuranic isotopes using a sodium-cooled fast reactor and a core of the sodium-cooled fast reactor. In this method, moderator assemblies and transuranic isotope production assemblies are arranged alternately in the first ring of the radial conversion zone, transuranic isotope production assemblies are arranged in the second ring, and a thermal neutron absorbing material is coated on the side of the first ring facing the core center; the core has a radial conversion zone, in which moderator assemblies and transuranic isotope production assemblies are arranged in the first ring, transuranic isotope production assemblies are arranged in the second ring, and a thermal neutron absorbing material is arranged on the side of the first ring facing the core center. This application concentrates the production of transuranic isotopes in the radial conversion zone, with good moderation effect, small perturbation to the core, and high production capacity.

Description

Technical Field

[0001] This application belongs to the technical field of sodium-cooled fast reactor for isotope production, and particularly relates to a method for producing transuranic isotopes using a sodium-cooled fast reactor and a core of the sodium-cooled fast reactor. Background Art

[0002] Sodium-cooled fast reactors have the characteristics of high neutron flux density (in the order of magnitude of 10 15 and high neutron energy. When producing 244 Cm, 238 Pu, 252 Cf and other transuranic isotopes using a sodium-cooled fast reactor, it is necessary to slow down the high-flux fast neutron spectrum to a suitable epithermal / thermal neutron spectrum, and then irradiate to produce 244 Cm, 238 Pu, 252 Cf and other transuranic isotopes.

[0003] The schematic diagram of the core part of the existing pool-type sodium-cooled fast reactor is as Figure 1 shown, including the arranged radial conversion assembly, safety rod control rod assembly 2, passive rod control rod assembly 3, regulating rod control rod assembly 4, compensating rod control rod assembly 5, and fuel assembly 6.

[0004] Currently, when producing transuranic isotopes using a sodium-cooled fast reactor, a moderator and a thermal neutron absorber material are added to the target. The fast neutron spectrum entering the target is slowed down to an epithermal / thermal neutron spectrum by the moderator to reduce the core perturbation. However, the moderation effect of this method is limited, and the core perturbation is still relatively large. The reason is that the space of a single component is limited. Both the moderator material and the target need to be placed, so the amount of moderator material that can be placed is small, and the moderation effect is limited. Since the fission reaction cross-section of epithermal / thermal neutrons is much higher than that of fast neutrons, placing a moderator in the core fuel area will cause a large core perturbation. Summary of the Invention

[0005] The main purpose of this application is to provide a method for producing transuranic isotopes using a sodium-cooled fast reactor and a core of the sodium-cooled fast reactor, so as to solve the problems of limited moderation effect and large core perturbation during the production of transuranic isotopes.

[0006] Another purpose of this application is to provide a method for producing transuranic isotopes using a sodium-cooled fast reactor and a core of the sodium-cooled fast reactor, so as to solve the problem that the fast neutron energy spectrum is not conducive to the production of transuranic isotopes. By slowing down the fast neutrons of the sodium-cooled fast reactor to epithermal / thermal neutrons, this application is beneficial to the production of transuranic isotopes.

[0007] To achieve the above purposes, this application provides the following technical solutions:

[0008] In the first aspect, this application provides a method for producing transuranic isotopes using a sodium-cooled fast reactor, including:

[0009] The moderator assemblies and the transuranic isotope production assemblies are arranged in an interspersed manner on the first circle of the radial conversion zone;

[0010] A plurality of the transuranic isotope production assemblies are arranged on the second circle of the radial conversion zone;

[0011] The side of the moderator assemblies and the transuranic isotope production assemblies arranged on the first circle of the radial conversion zone facing the core center is coated with a thermal neutron absorption material.

[0012] In some embodiments, the moderator assemblies and the transuranic isotope production assemblies are arranged alternately in sequence on the first circle of the radial conversion zone.

[0013] In some embodiments, the moderator assemblies and the transuranic isotope production assemblies are arranged in an interspersed manner on the first circle of the radial conversion zone by a refueling machine, and the transuranic isotope production assemblies are arranged on the second circle of the radial conversion zone.

[0014] In some embodiments, different materials to be irradiated are arranged in different transuranic isotope production assemblies, and the transuranic isotope production assemblies are arranged in the core of a sodium-cooled fast reactor to simultaneously produce a variety of different isotopes.

[0015] In some embodiments, the thermal neutron absorption material uses Eu2O3 thermal neutron absorption material.

[0016] In some embodiments, a ZrH moderator is arranged inside the moderator assembly.

[0017] In a second aspect, the present application provides a core of a sodium-cooled fast reactor for producing transuranic isotopes, which has a radial conversion zone. The radial conversion zone includes a first circle of the radial conversion zone and a second circle of the radial conversion zone; the moderator assemblies and the transuranic isotope production assemblies are arranged on the first circle of the radial conversion zone, the transuranic isotope production assemblies are arranged on the second circle of the radial conversion zone, and a thermal neutron absorption material is arranged on the side of the first circle of the radial conversion zone facing the core center.

[0018] In some embodiments, the moderator assemblies and the transuranic isotope production assemblies are arranged alternately in sequence on the first circle of the radial conversion zone.

[0019] In some embodiments, the thermal neutron absorption material is Eu2O3 thermal neutron absorption material.

[0020] In some embodiments, the moderator assembly is a ZrH moderator assembly.

[0021] Compared with the prior art, the method for producing transuranic isotopes using a sodium-cooled fast reactor and the core of the sodium-cooled fast reactor provided by the present application have the following beneficial effects:

[0022] In this application, a dedicated epithermal neutron / thermal neutron isotope production area is arranged around the core of a sodium-cooled fast reactor, and transuranic isotopes are concentrated in the radial conversion zone for production. This application has good moderation effect, small disturbance to the core, and large production capacity. Among them, the dedicated epithermal neutron / thermal neutron isotope production area does not exist per se. By arranging moderator assemblies in the radial conversion zone in an interspersed manner to slow down fast neutrons into epithermal neutrons, then other positions in the radial conversion zone except for the moderator assemblies are the epithermal neutron / thermal neutron isotope production areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of this application, the drawings required for the technical description will be briefly introduced below.

[0024] Figure 1 It is a schematic diagram of the arrangement of each component of the core of a pool-type sodium-cooled fast reactor provided by the prior art;

[0025] Figure 2 It is a partial structural design schematic diagram of the dedicated epithermal neutron / thermal neutron area for transuranic isotope production provided by an embodiment of this application;

[0026] Figure 3 It is a schematic diagram of the core design of the dedicated epithermal neutron / thermal neutron area for transuranic isotope production provided by an embodiment of this application.

[0027] DESCRIPTION OF THE REFERENCE NUMERALS:

[0028] 1. Radial conversion zone; 2. Safety rod control rod assembly; 3. Passive rod control rod assembly; 4. Regulating rod control rod assembly; 5. Compensation rod control rod assembly; 6. Fuel assembly; 7. Thermal neutron absorber material; 8. Moderator assembly; 9. Transuranic isotope production assembly. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following will be further described in detail through specific embodiments.

[0030] This application is different from the prior art in that the moderator, target material, etc. are directly arranged in a target or device and inserted into the core in the form of components to realize the production of transuranic isotopes. This application improves the core design of a sodium-cooled fast reactor, constructs an epithermal neutron / thermal neutron production area in the core, and arranges a transuranic isotope production assembly 9 in this production area. According to the characteristics of a fast neutron reactor, this application is designed as a high-leakage and fuel-target interspersed arrangement scheme. This application can set up a dedicated production area for transuranic isotopes in the radial conversion zone 1, that is, a dedicated epithermal neutron / thermal neutron area for transuranic isotopes.

[0031] Furthermore, in the present application, the moderator assembly 8 is designed in an interdigitated manner in the inner ring (the first ring, close to the core center) of the radial conversion zone, and the target and the moderator assembly 8 are arranged in an interdigitated manner. To reduce the impact of neutron moderation on the core disturbance, a thermal neutron absorption material 7 is arranged on one side of the inner ring moderator assembly and the side close to the core in the dedicated production area of transuranic isotopes to absorb the epithermal neutrons / thermal neutrons moderated inside the assembly and reduce the core disturbance. At the same time, a large number of targets are arranged in the second ring of the radial conversion zone to produce multiple transuranic isotopes simultaneously.

[0032] Example 1

[0033] The components are replaced and arranged in the core structure of the epithermal neutron / thermal neutron production area through the core refueling system, as follows:

[0034] This embodiment provides a method for producing transuranic isotopes using a sodium-cooled fast reactor, including:

[0035] The moderator assembly 8 and the transuranic isotope production assembly 9 are arranged in an interdigitated manner in the first ring of the radial conversion zone through a refueling machine. For example, the moderator assemblies 8 are arranged at intervals in the first ring of the radial conversion zone, and adjacent two moderator assemblies 8 are arranged with one assembly position in between, and the transuranic isotope production assembly 9 is arranged at this assembly position. The moderator assembly 8 and the transuranic isotope production assembly 9 are arranged in an interdigitated manner in the first ring of the radial conversion zone, arranged in a hexagonal ring.

[0036] It should be noted that in this embodiment, except for the moderator assembly in the radial conversion zone 1, other positions in the radial conversion zone can be regarded as the transuranic isotope production area, and the transuranic isotope production assembly 9 (isotope target) is placed in the corresponding transuranic isotope production area.

[0037] As Figure 2 shown, the side of the moderator assembly 8 and the transuranic isotope production assembly 9 in the first ring of the radial conversion zone close to or facing the core center is coated with the thermal neutron absorption material 7 to reduce the thermal neutron disturbance, and the transuranic isotope production assembly 9 is arranged in the second ring of the radial conversion zone using a refueling machine. It should be noted that the radial conversion zone may not be entirely arranged with isotope production assemblies (transuranic isotope production assembly 9), but other components are used for occupying positions, such as stainless steel components that only play a role in occupying positions to prevent the deformation of the core structure.

[0038] Through the arrangement method of the core components, the position of the transuranic isotope production assembly 9 has a high flux of epithermal neutrons / thermal neutrons. In the transuranic isotope production assembly 9, a large number of multiple transuranic isotopes are produced. By arranging different materials to be irradiated in different transuranic isotope production assemblies 9 and arranging these transuranic isotope production assemblies 9 into the core of the sodium-cooled fast reactor, multiple different isotopes can be produced simultaneously in the core.

[0039] Optionally, the thermal neutron absorption material 7 is Eu2O3 thermal neutron absorption material.

[0040] Optionally, a ZrH moderator is provided inside the moderator assembly 8.

[0041] During the production of transuranium isotopes, the moderator assembly 8 and the transuranium isotope production assembly 9 are inserted and removed in a refueling manner.

[0042] Example Two

[0043] Example Two provides a sodium-cooled fast reactor core for producing transuranium isotopes, which has a radial conversion zone 1. The radial conversion zone 1 includes a first ring and a second ring of the radial conversion zone. The moderator assembly 8 and the transuranium isotope production assembly 9 are arranged in the radial conversion zone 1. Example Two correspondingly improves the sodium-cooled fast reactor core based on Example One, so that the core can produce transuranium isotopes.

[0044] In the design of the sodium-cooled fast reactor core in this embodiment, the moderator and the target are separated separately, which can make the production capacity larger and overcome the problem of limited moderation effect caused by setting the moderator inside the target in the prior art. In this embodiment, the alternately spaced positions in the first ring of the radial conversion zone are used as the moderation zone (for example, the arrangement position of the moderator assembly 8 described in Example One). The moderation zone is considered as a whole, rather than simply setting the moderator inside the target to obtain the moderation effect required for transuranium isotope production.

[0045] In this embodiment, a thermal neutron absorption material is provided at the edge close to the fuel zone to reduce the disturbance to the core.

[0046] Among them, the improvement of the sodium-cooled fast reactor core provided in this embodiment lies in:

[0047] The moderator assembly 8 and the transuranium isotope production assembly 9 are arranged in an interspersed manner in the first ring of the radial conversion zone;

[0048] The transuranium isotope production assembly 9 is arranged in the second ring of the radial conversion zone;

[0049] On the side of the first ring of the radial conversion zone facing the core center (i.e., the edge close to the fuel zone), a thermal neutron absorption material 7 is arranged.

[0050] If the transuranium isotope production assembly 9 is not fully arranged in the radial conversion zone, other components are used to occupy the vacant positions, such as stainless steel components that only play a role in occupying positions to prevent the deformation of the core structure.

[0051] The components arranged in other areas of the core provided in this embodiment are the same as those arranged in the existing sodium-cooled fast reactor core. For example, they are the same as the arrangement positions of the safety rod control rod assembly 2, the passive rod control rod assembly 3, the regulating rod control rod assembly 4, the compensating rod control rod assembly 5, and the fuel assembly 6, such as Figure 1As shown, it will not be elaborated here. In the radial conversion zone 1 of this embodiment, the moderator assembly 8 and the transuranium isotope production assembly 9 are arranged, and no radial conversion zone assembly is arranged.

[0052] Optionally, the moderator assemblies 8 are arranged at intervals on the first circle of the radial conversion zone. Adjacent two moderator assemblies 8 are arranged with one assembly position in between, and the transuranium isotope production assembly 9 is arranged at this assembly position. The moderator assemblies 8 and the transuranium isotope production assemblies 9 are arranged staggeredly on the first circle of the radial conversion zone. With such an arrangement, the advantages are that it can slow down fast neutrons into epithermal / thermal neutrons suitable for the production of transuranium isotopes, and can provide a thermal neutron production area on the first circle of the radial assemblies with a relatively high neutron flux density.

[0053] Optionally, the thermal neutron absorption material 7 is Eu2O3 thermal neutron absorption material.

[0054] Optionally, the moderator assembly 8 is a ZrH moderator assembly.

[0055] This application arranges a dedicated epithermal neutron / thermal neutron area for irradiating and producing transuranium isotopes in the core of a sodium-cooled fast reactor, and uses this area to produce transuranium isotopes, improving the moderation effect, reducing the core perturbation, and increasing the production capacity.

[0056] The above are only the specific embodiments of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by this application should be covered within the protection scope of this application.

Claims

1. A method for producing transuranium isotopes using a sodium-cooled fast reactor, characterized in that, Including: The moderator assemblies (8) and the transuranium isotope production assemblies (9) are arranged in an interspersed manner on the first ring of the radial conversion zone; A plurality of the transuranium isotope production assemblies (9) are arranged on the second ring of the radial conversion zone; The moderator assemblies (8) and the transuranium isotope production assemblies (9) arranged on the first ring of the radial conversion zone are coated with a thermal neutron absorption material (7) on the side facing the core center; The moderator assemblies (8) and the transuranium isotope production assemblies (9) are arranged alternately in sequence on the first ring of the radial conversion zone.

2. The method for producing transuranium isotopes using a sodium-cooled fast reactor according to claim 1, wherein The moderator assemblies (8) and the transuranium isotope production assemblies (9) are arranged in an interspersed manner on the first ring of the radial conversion zone by a refueling machine, and the transuranium isotope production assemblies (9) are arranged on the second ring of the radial conversion zone.

3. The method for producing transuranic isotopes using a sodium-cooled fast reactor according to claim 1, characterized in that, Different materials to be irradiated are arranged in different transuranium isotope production assemblies (9), and the transuranium isotope production assemblies (9) are arranged in the core of a sodium-cooled fast reactor to simultaneously produce a variety of different isotopes.

4. The method for producing transuranium isotopes using a sodium-cooled fast reactor according to claim 1, characterized in that, The thermal neutron absorption material (7) uses Eu2O3 thermal neutron absorption material.

5. The method for producing transuranic isotopes using a sodium-cooled fast reactor according to claim 1, characterized in that, The moderator assembly (8) is provided with a ZrH moderator.

6. A sodium-cooled fast reactor core for producing transuranic isotopes, characterized in that, There is a radial conversion zone, and the radial conversion zone includes a first ring of the radial conversion zone and a second ring of the radial conversion zone; the moderator assemblies (8) and the transuranium isotope production assemblies (9) are arranged on the first ring of the radial conversion zone, the transuranium isotope production assemblies (9) are arranged on the second ring of the radial conversion zone, and a thermal neutron absorption material (7) is arranged on the side of the first ring of the radial conversion zone facing the core center; The moderator assemblies (8) and the transuranium isotope production assemblies (9) are arranged alternately in sequence on the first ring of the radial conversion zone.

7. The sodium-cooled fast reactor core for producing transuranic isotopes according to claim 6, characterized in that, The thermal neutron absorption material (7) is Eu2O3 thermal neutron absorption material.

8. The sodium-cooled fast reactor core for producing transuranium isotopes according to claim 6, characterized in that, The moderator assembly (8) is a ZrH moderator assembly.

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