Method for producing super-uranium isotope by using sodium-cooled fast reactor and sodium-cooled fast reactor core

Abstract

The invention belongs to the technical field of production of isotopes by a sodium-cooled fast reactor, and aims to solve the problems that the moderation effect is limited, the reactor core disturbance is relatively large and fast neutron energy spectrum is not beneficial to the production of the ultra-uranium isotopes during the production of the ultra-uranium isotopes. The invention provides a method for producing a super-uranium isotope by using a sodium-cooled fast reactor and a sodium-cooled fast reactor core. According to the method, moderator assemblies and super-uranium isotope production assemblies are arranged on a first circle of a radial conversion area in a flower arrangement mode, the super-uranium isotope production assemblies are arranged on a second circle of the radial conversion area, and the side, facing the center of the reactor core, of the first circle is coated with a thermal neutron absorption material; the reactor core is provided with a radial conversion area, moderator assemblies and super-uranium isotope production assemblies are arranged on a first circle of the radial conversion area, the super-uranium isotope production assemblies are arranged on a second circle of the radial conversion area, and thermal neutron absorbing materials are arranged on the side, facing the center of the reactor core, of the first circle. The super-uranium isotope is concentrated in the radial conversion region for production, the moderation effect is good, the disturbance to the reactor core is small, and the productivity is high.

Description

Technical Field

[0001] The present application belongs to the technical field of isotope production by sodium-cooled fast reactors, and in particular relates to a method for producing transuranic isotopes by using a sodium-cooled fast reactor and a sodium-cooled fast reactor core. Background Art

[0002] Sodium-cooled fast reactors have a high neutron flux density (10 15 The characteristics of sodium-cooled fast reactor production are 244 Cm, 238 Pu, 252 Transuranic isotopes such as Cf require the high-flux fast neutron spectrum to be slowed down into a suitable epithermal / thermal neutron spectrum, and then irradiated to produce 244 Cm, 238 Pu, 252 Transuranic isotopes such as Cf.

[0003] The schematic diagram of the core of the existing pool-type sodium-cooled fast reactor is as follows: Figure 1 As shown, it includes a radial conversion assembly, a safety rod control rod assembly 2, a passive rod control rod assembly 3, an adjustment rod control rod assembly 4, a compensation rod control rod assembly 5, and a fuel assembly 6.

[0004] At present, when using sodium-cooled fast reactors to produce transuranic isotopes, moderators and thermal neutron absorbing materials are added to the target. The fast neutron spectrum entering the target is slowed down to epithermal neutron / thermal neutron spectrum by the moderator to reduce the core disturbance. However, the moderation effect of this method is limited, and the core disturbance is still large. The reason is that the space of a single component is limited, and both the moderator material and the target must be placed. Therefore, less moderator material can be placed, and the moderation effect is limited; since the fission reaction cross section of epithermal neutrons / thermal neutrons is much higher than that of fast neutrons, placing a moderator in the core fuel area will cause large disturbances to the core. Summary of the invention

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

[0006] Another object of the present application is to provide a method for producing transuranic isotopes using a sodium-cooled fast reactor and a sodium-cooled fast reactor core, 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 into epithermal neutrons / thermal neutrons, the present application is conducive to the production of transuranic isotopes.

[0007] In order to achieve the above objectives, this application provides the following technical solutions:

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

[0009] Arrange the moderator assembly and transuranic isotope production assembly in a flower arrangement on the first circle of the radial conversion zone;

[0010] Arranging a plurality of said transuranic isotope production assemblies on the second circle of the radial conversion zone;

[0011] The moderator assembly and the transuranic isotope production assembly arranged on the first circle of the radial conversion zone are coated with thermal neutron absorbing material on one side facing the core center.

[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 transuranium isotope production assemblies are arranged in a flower arrangement on a first circle of the radial conversion zone by a material changer, and the transuranium isotope production assemblies are arranged on a 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 a sodium-cooled fast reactor core to simultaneously produce a variety of different isotopes.

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

[0016] In some embodiments, a ZrH moderator is disposed in the moderator assembly.

[0017] In a second aspect, the present application provides a sodium-cooled fast reactor core for producing transuranium isotopes, comprising a radial conversion zone, wherein the radial conversion zone includes a first circle of radial conversion zones and a second circle of radial conversion zones; the moderator assembly and the transuranium isotope production assembly are arranged on the first circle of radial conversion zones, the transuranium isotope production assembly is arranged on the second circle of radial conversion zones, and thermal neutron absorbing material is arranged on the side of the first circle of radial conversion zones toward the center of the core.

[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 absorbing material is Eu2O3 thermal neutron absorbing 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 sodium-cooled fast reactor core provided by the present application have the following beneficial effects:

[0022] The present application sets up a dedicated epithermal neutron / thermal neutron isotope production area outside the core of a sodium-cooled fast reactor, and concentrates transuranic isotopes in the radial conversion zone for production. The present application has a good moderation effect, small disturbance to the core, and large production capacity. Among them, the dedicated epithermal neutron / thermal neutron isotope production area itself does not exist. By arranging the moderator components in the radial conversion zone, the slowed fast neutrons are epithermal neutrons, so the other positions in the radial conversion zone except the moderator components are the epithermal neutron / thermal neutron isotope production area. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for the technical description.

[0024] Figure 1 A schematic diagram of the arrangement of various components of a pool-type sodium-cooled fast reactor core provided by the prior art;

[0025] Figure 2 A schematic diagram of a partial structural design of an epithermal neutron / thermal neutron region dedicated to transuranium isotope production provided in an embodiment of the present application;

[0026] Figure 3 Schematic diagram of epithermal neutron / thermal neutron region core design for transuranic isotope production provided in an embodiment of the present application.

[0027] Description of reference numerals:

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

[0029] The following is further explained in detail through specific implementation methods.

[0030] This application is different from the prior art that directly arranges the moderator, target material, etc. in a target or device and inserts it into the core in the form of an assembly to achieve the production of transuranium 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 transuranium isotope production assembly 9 in the production area. According to the characteristics of the fast neutron reactor, this application is designed as a high leakage and fuel and target arrangement scheme. This application can set a transuranium isotope dedicated production area in the radial conversion zone 1, that is, a transuranium isotope dedicated epithermal neutron / thermal neutron area.

[0031] Furthermore, the present application designs a moderator assembly 8 in a flower arrangement in the inner circle (first circle, close to the center of the core) of the radial conversion zone, and the target is flower-arranged with the moderator assembly 8. In order to reduce the impact of neutron moderation on the core disturbance, a thermal neutron absorbing material 7 is arranged on the side of the inner circle moderation assembly and the transuranium isotope dedicated production area close to the core to absorb the epithermal neutrons / thermal neutrons after moderation inside the assembly to reduce the core disturbance. At the same time, a large number of targets are arranged in the second circle of the radial conversion zone to produce multiple transuranium isotopes at the same time.

[0032] Embodiment 1

[0033] The epithermal / thermal neutron production area is constructed in the core by replacing and arranging components in the core refueling system as follows:

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

[0035] The moderator assemblies 8 and the transuranium isotope production assemblies 9 are arranged in a flower arrangement in the first circle of the radial conversion zone by means of a material changer. For example, the moderator assemblies 8 are arranged at intervals in the first circle of the radial conversion zone, and two adjacent moderator assemblies 8 are arranged at an interval of one assembly position, and the transuranium isotope production assembly 9 is arranged at the assembly position. The moderator assemblies 8 and the transuranium isotope production assemblies 9 are arranged in a staggered manner in the first circle of the radial conversion zone, and are arranged in a hexagonal circle.

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

[0037] like Figure 2 As shown, the moderator assembly 8 and the transuranium isotope production assembly 9 of the first circle of the radial conversion zone are coated with thermal neutron absorbing material 7 on the side close to or facing the center of the core to reduce thermal neutron disturbance, and the transuranium isotope production assembly 9 is arranged in the second circle of the radial conversion zone using a material changer. It should be noted that the isotope production assembly (transuranium isotope production assembly 9) may not be arranged in all radial conversion zones, but other assemblies are used for place-taking, such as stainless steel assemblies that only play a place-taking role to prevent the core structure from deforming.

[0038] By arranging the core components, the position of the transuranium isotope production component 9 is provided with a high flux of epithermal neutrons / thermal neutrons, and a large number of transuranium isotopes are produced in the transuranium isotope production component 9. By arranging different materials to be irradiated in different transuranium isotope production components 9, these transuranium isotope production components 9 are arranged in the core of a sodium-cooled fast reactor, thereby realizing the simultaneous production of a variety of different isotopes in the core.

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

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

[0041] During the production of transuranic isotopes, the moderator assembly 8 and the transuranic isotope production assembly 9 are replaced in and out in a material replacement manner.

[0042] Embodiment 2

[0043] Embodiment 2 provides a sodium-cooled fast reactor core for producing transuranium isotopes, comprising a radial conversion zone 1, wherein the radial conversion zone 1 comprises a first radial conversion zone ring and a second radial conversion zone ring, and a moderator assembly 8 and a transuranium isotope production assembly 9 are arranged in the radial conversion zone 1. Embodiment 2 improves the sodium-cooled fast reactor core accordingly based on Embodiment 1, so that the core can produce transuranium isotopes.

[0044] In the core design of the sodium-cooled fast reactor, this embodiment separates the moderator and the target, which can increase the production capacity and overcome the problem of limited moderation effect caused by setting the moderator in the target in the prior art. This embodiment uses the alternating positions of the first circle of the radial conversion zone as the moderation zone (for example, the arrangement position of the moderator assembly 8 recorded in the first embodiment), and considers the moderation zone as a whole, rather than simply setting the moderator in the target to obtain the moderation effect required for transuranium isotope production.

[0045] In this embodiment, thermal neutron absorbing materials are arranged near the edge of the fuel zone to reduce disturbance to the core.

[0046] The improvement of the sodium-cooled fast reactor core provided in this embodiment is:

[0047] The first circle of the radial conversion zone is arranged with moderator assembly 8 and transuranic isotope production assembly 9;

[0048] The second circle of the radial conversion zone is arranged with a transuranic isotope production assembly 9;

[0049] Thermal neutron absorbing material 7 is arranged on one side of the first circle of the radial conversion zone facing the core center (ie, close to the edge of the fuel zone).

[0050] If the radial transition zone is not completely arranged with transuranic isotope production assemblies 9, other assemblies are used to occupy the vacancies, such as stainless steel assemblies that only serve as placeholders to prevent deformation of the core structure.

[0051] The components arranged in other areas of the core provided in this embodiment are consistent with the existing sodium-cooled fast reactor core arrangement, for example, 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 are consistent, such as Figure 1The radial conversion zone 1 of this embodiment is provided with a moderator assembly 8 and a transuranic isotope production assembly 9, but no radial conversion zone assembly is provided.

[0052] Optionally, the moderator assemblies 8 are arranged at intervals on the first circle of the radial conversion zone, and two adjacent moderator assemblies 8 are arranged at an interval of one assembly position, and the assembly position is arranged with the transuranium isotope production assembly 9. The moderator assemblies 8 and the transuranium isotope production assembly 9 are arranged alternately on the first circle of the radial conversion zone. Such an arrangement has the advantage that fast neutrons can be moderated into epithermal / thermal neutrons suitable for producing transuranium isotopes, and a thermal neutron production area can be provided in the first circle of radial assemblies with a higher 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] The present application arranges an epithermal neutron / thermal neutron area dedicated to irradiation production of transuranic isotopes in the core of a sodium-cooled fast reactor, and utilizes the area to produce transuranic isotopes, thereby improving the moderation effect, reducing core disturbances, and increasing production capacity.

[0056] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A method for producing transuranic isotopes using a sodium-cooled fast reactor, characterized in that: include: The moderator assembly (8) and the transuranic isotope production assembly (9) are arranged in a flower arrangement on the first circle of the radial conversion zone; Arrange a plurality of the transuranic isotope production assemblies (9) on the second circle of the radial conversion zone; The moderator assembly (8) and the transuranic isotope production assembly (9) arranged on the first circle of the radial conversion zone are coated with thermal neutron absorbing material (7) on one side facing the center of the core.

2. The method for producing transuranic isotopes using a sodium-cooled fast reactor according to claim 1, characterized in that: The moderator assembly (8) and the transuranic isotope production assembly (9) are arranged alternately in sequence on the first circle 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: The moderator assembly (8) and the transuranic isotope production assembly (9) are arranged in a flower pattern on a first circle of the radial conversion zone by a material changer, and the transuranic isotope production assembly (9) is arranged on a second circle of the radial conversion zone.

4. 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 transuranic isotope production assemblies (9), and the transuranic isotope production assemblies (9) are arranged in a sodium-cooled fast reactor core to simultaneously produce a plurality of different isotopes.

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

6. 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.

7. A sodium-cooled fast reactor core for producing transuranic isotopes, characterized in that: The invention has a radial conversion zone, the radial conversion zone comprising a first radial conversion zone circle and a second radial conversion zone circle; the moderator assembly (8) and the transuranium isotope production assembly (9) are arranged on the first radial conversion zone circle, the transuranium isotope production assembly (9) is arranged on the second radial conversion zone circle, and a thermal neutron absorbing material (7) is arranged on the side of the first radial conversion zone circle facing the core center.

8. The sodium-cooled fast reactor core for producing transuranic isotopes according to claim 7, characterized in that: The moderator assembly (8) and the transuranic isotope production assembly (9) are arranged alternately in sequence on the first circle of the radial conversion zone.

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

10. The sodium-cooled fast reactor core for producing transuranic isotopes according to claim 7, characterized in that: The moderator assembly (8) is a ZrH moderator assembly.

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