A simplified neutron source cold package, a reactor-based cold neutron source, and a reactor.

Abstract

A simplified neutron source cold package, a reactor-based cold neutron source, and a reactor are disclosed, belonging to the field of nuclear technology. The simplified neutron source cold package includes a moderator input tube, a moderator output tube, a cold package cavity, and a coolant circulation pipeline. The moderator input tube includes an inflow section parallel to the moderator output tube and a curved recirculation section. The cold package cavity is connected to the recirculation section, and its maximum cross-sectional area covers the azimuth range of the neutron conduit arrangement. The coolant circulation pipeline includes an input jacket, an output jacket, and a cold package cavity jacket, with a vacuum space between the cold package cavity jacket and the input jacket.

Description

Technical Field

[0001] This invention belongs to the field of nuclear technology, specifically relating to a simplified neutron source cold package, a reactor-based cold neutron source, and a reactor. Background Technology

[0002] Cold neutron sources are a crucial foundation of neutron scattering technology. Their core component is the moderator circulation loop housed within a vacuum chamber, which primarily comprises a heat exchanger, a cold pack, and related piping. Within the cold pack, the moderator interacts with thermal neutrons, moderating them into cold neutrons. The structure of the cold pack significantly impacts the performance of the cold neutron source. Existing cold packs are complex, difficult to manufacture, and suffer from insufficient moderator utilization efficiency. Redundant moderators also increase heat dissipation pressure. Therefore, providing a simplified neutron source cold pack is of significant importance for improving the efficiency of cold neutron sources. Summary of the Invention

[0003] The purpose of this invention is to provide a simplified neutron source cold package to improve the efficiency of the cold neutron source. This invention also provides a reactor-based cold neutron source and a reactor.

[0004] According to one embodiment of the present invention, a simplified neutron source cold package is provided, comprising a moderator input tube, a moderator output tube, a cold package cavity, and a coolant circulation pipeline, wherein:

[0005] The moderator input pipe includes an inflow section and a return section. The inflow section is arranged parallel to the moderator output pipe, and the return section is curved relative to the inflow section.

[0006] The cold envelope cavity is connected to the reflux section, and the cross-sectional area of ​​the cold envelope cavity is larger than the cross-sectional areas of the moderator input tube and the moderator output tube. The maximum cross-section of the cold envelope cavity covers the azimuth range of the neutron conduit arrangement.

[0007] The coolant circulation pipeline includes an input jacket, an output jacket, and a cold envelope jacket. The input jacket is configured as a jacketed sleeve surrounding the moderator input pipe, the output jacket is configured as a jacketed sleeve surrounding the moderator output pipe, and the cold envelope jacket is configured as a jacketed cavity surrounding the cold envelope. There is a vacuum gap between the cold envelope jacket and the input jacket.

[0008] Compared to existing neutron source cold packs, this cold pack avoids the occurrence of a three-layer thin-walled irregular structure by optimizing the structure of the cold pack cavity sandwich. On the one hand, it reduces neutron loss caused by multiple layers of walls. On the other hand, by optimizing the cross-sectional shape of the cold pack, it improves the utilization efficiency of the moderator in the cold pack and reduces the cooling and heat dissipation requirements.

[0009] Furthermore, in some embodiments, the cold pack includes an upper connecting section, a lower connecting section, and a middle section, wherein the upper connecting section and the lower connecting section have a gradually changing cross-sectional area, and the upper connecting section protrudes toward the inflow section.

[0010] Furthermore, in some embodiments, the cross-section of the middle section is a fan-shaped surface arranged around the inflow section.

[0011] Furthermore, in some embodiments, the input interlayer and the cross-section of the moderator input pipe are concentric, and the output interlayer and the cross-section of the moderator output pipe are concentric.

[0012] Furthermore, in some embodiments, the reflux section is connected to the bottom of the cold envelope cavity, and the moderator output pipe is connected to the top of the cold envelope cavity.

[0013] According to another aspect of the present invention, a reactor-based cold neutron source is provided, disposed within a reactor, the reactor-based cold neutron source including a cold package, the cold package being configured as a simplified neutron source cold package provided in any of the foregoing embodiments.

[0014] Furthermore, in some embodiments, the reactor-based cold neutron source uses liquid hydrogen or deuterium as a moderator and helium as a coolant.

[0015] According to another aspect of the present invention, a reactor is provided, including a reactor-based cold neutron source, said reactor-based cold neutron source being configured as a reactor-based cold neutron source employing a simplified neutron source cold package as provided in any of the foregoing embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the neutron source cold package structure in one embodiment;

[0017] Figure 2 This is a schematic diagram of the cross-sectional structure of the middle section of the cold pack in one embodiment;

[0018] Figure 3 This is a schematic diagram of a pair of proportional neutron source cold package structures;

[0019] Figure 4 This is a schematic diagram of the cross-sectional structure of a pair of proportional neutron source cold packs.

[0020] Meaning of the reference numerals in the attached figures:

[0021] 1-Moderator inlet pipe; 11-Inflow section; 12-Return section; 2-Cold pack cavity; 21-Lower connecting section; 22-Middle section; 23-Upper connecting section; 24-Irregularly shaped cold pack clamp cavity; 3-Moderator outlet pipe; 4-Inlet jacket; 5-Cold pack cavity jacket; 6-Outlet jacket; 7-Coolant cavity; 71-Connecting hole.

[0022] The purpose of the above-described drawings is to provide a detailed description of the present invention so that those skilled in the art can understand the technical concept of the invention, and is not intended to limit the invention. For the sake of brevity, the above-described drawings only schematically depict the structures related to the technical features of the present invention, and do not depict the complete structure and all details strictly according to actual scale. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0024] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment herein. The phrase appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive, independent, or alternative embodiments. Those skilled in the art will understand that the embodiments herein can be combined with other embodiments without causing structural conflicts.

[0025] In this description, unless otherwise explicitly specified and limited, the technical terms "installation," "connection," "joining," etc., should be interpreted broadly, for example, referring to movable connections, fixed connections, or integration. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0026] In this description, terms such as "upper," "lower," "left," "right," "lateral," "longitudinal," "height," "length," and "width," which indicate orientation or positional relationships, are intended to accurately describe the embodiments and simplify the description, rather than limiting the parts or structures involved to have a specific orientation, or to be installed or operated in a specific orientation, and should not be construed as limiting the embodiments in this document.

[0027] In this description, terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating relative importance or limiting the number, specific order, or primary / secondary relationship of the described technical features. In this description, "multiple" means at least two.

[0028] Neutron scattering technology is widely used in industries such as military, energy, semiconductors, and new materials, and the demand is increasing with technological advancements. The foundation of neutron scattering technology is the cold neutron source, and reactor-based cold neutron sources are currently the most stable and reliable cold neutron source solution. The basic principle of a reactor-based cold neutron source is to establish a region containing a cryogenic neutron moderator within the high thermal neutron flux region of the reactor. The cryogenic neutron moderator slows down the thermal neutrons until they reach thermal equilibrium with the moderator, and then transports them outside the reactor via neutron transport systems such as neutron conduits. The main component that contains the cryogenic moderator and reacts with the thermal neutrons is the cold pack of the cold neutron source, and the structure of the cold pack has a crucial impact on the performance and efficiency of the cold neutron source.

[0029] Currently, typical cold package structures for reactor-based cold neutron sources include... Figure 3 and Figure 4 As shown, the system includes a moderator input pipe 1, a cold envelope cavity 2, a moderator output pipe 3, an input interlayer 4, a cold envelope cavity interlayer 5, an output interlayer 6, and a coolant cavity 7. The moderator flows into the cold envelope cavity 2 through the moderator input pipe 1. The cold envelope cavity 2 is the main region where the moderator moderates thermal neutrons. Its main body is an annular, irregularly shaped cold envelope cavity 24. The space in the middle of the irregularly shaped cold envelope cavity forms the coolant cavity 7. After the moderator moderates the thermal neutrons in the cold envelope cavity 2, it flows out through the moderator output pipe 3 to the heat exchanger (not shown) of the cold neutron source. After being cooled by the heat exchanger, it flows back through the moderator input pipe 1, achieving a thermosiphon cycle. Because energy exchange occurs during the moderation of thermal neutrons by the moderator, the deposited nuclei in the moderator generate heat and rise in temperature; therefore, a coolant is needed to cool the moderator. Coolant flows into the coolant cavity 7 through the input interlayer 4. A connecting hole 71 is provided at the bottom of the irregularly shaped cold pack cavity 24. The coolant flows out of the coolant cavity 7 through the connecting hole 71, enters the cold pack cavity interlayer 5 on the outer periphery of the irregularly shaped cold pack cavity 24, and finally flows out through the output interlayer 6. In this cold pack structure, both the inner and outer surfaces of the irregularly shaped cold pack cavity 24 can be sufficiently cooled by the coolant, allowing the deposited nuclear heat to be effectively dissipated. The interlayer also forms a protective boundary to prevent moderator leakage.

[0030] However, as Figure 4 As shown, the irregularly shaped cold-clamped cavity 24 has a multi-layered nested structure, and its overall structure is very complex and difficult to manufacture. At the same time, the cross-section of the irregularly shaped cold-clamped cavity 24 is annular, but due to structural limitations, the distribution range of the neutron extraction tubes cannot cover the entire annular surface. This results in a considerable portion of the cold neutrons moderated by the moderator in the irregularly shaped cold-clamped cavity 24 not being utilized, but their nuclear heating still requires cooling by the coolant, which increases the heat dissipation pressure. Furthermore, the multi-layered wall structure itself also leads to a decrease in the neutron fluence rate.

[0031] In order to overcome the above-mentioned problems of the prior art, one aspect of the present invention provides a simplified neutron source cold package, which can simplify the cold package structure and improve the utilization efficiency of the moderator.

[0032] The cold pack structure of the neutron source is as follows: Figure 1 and Figure 2 As shown, it includes a moderator inlet pipe 1, a moderator outlet pipe 3, a cold envelope cavity 2, and a coolant circulation pipeline.

[0033] The moderator input pipe 1 includes an inflow section 11 and a return section 12. The inflow section 11 is arranged parallel to the moderator output pipe 3, while the return section 12 is bent into a U-shape relative to the inflow section 11. The cold envelope 2 is connected to the return section 12, and its cross-sectional area is larger than that of the moderator input pipe 1 and the moderator output pipe 3, forming an enlarged structure. The maximum cross-section of the cold envelope 2 can cover the azimuth range of the neutron conduit arrangement.

[0034] The coolant circulation pipeline includes an input jacket 4, an output jacket 6, and a cold cavity jacket 5. The input jacket 4 is a jacketed sleeve surrounding the moderator input pipe, the output jacket 6 is a jacketed sleeve surrounding the moderator output pipe, and the cold cavity jacket 5 is a jacketed cavity surrounding the cold cavity 2. A vacuum gap exists between the cold cavity jacket 5 and the input jacket 4. In a preferred embodiment, the cross-sections of the input jacket 4 and the moderator input pipe 1 are concentric, and the cross-sections of the output jacket 6 and the moderator output pipe 3 are also concentric.

[0035] In a preferred embodiment, the cold envelope 2 includes an upper connecting section 23 at the top, a lower connecting section 21 at the bottom, and a middle section 22 between the upper connecting section 23 and the lower connecting section 21. The upper connecting section 23 and the lower connecting section 21 have gradually changing cross-sectional areas, with the upper connecting section 23 protruding towards the inflow section 11. Further, the middle section 22 has a cross-sectional shape that is a fan-shaped surface surrounding the inflow section 11. The lower connecting section 21 of the cold envelope 2 connects to the return section 12 of the moderator input pipe 1, while the upper connecting section 23 connects to the moderator output pipe 3.

[0036] The neutron source cold pack has a simple structure, avoiding complex multi-nested structures and effectively reducing manufacturing difficulty. Due to the reduction in nested structures, the number of walls that thermal neutrons need to pass through to contact the moderator is reduced, resulting in a corresponding increase in thermal neutron flux. Furthermore, the overall structure of the cold pack cavity 2 not only conforms to the distribution of the vacuum cylinder and neutron conduit, increasing the neutron flux, but also improves the structural strength of the cold pack cavity 2, reducing the risk of damage. Simultaneously, because the cross-sectional shape of the cold pack cavity 2 is fan-shaped instead of the annular shape used in the prior art, the distribution of the moderator participating in the moderation of thermal neutrons is more consistent with the spatial distribution of the neutron conduit, reducing the moderator volume while improving the utilization efficiency of the moderator; the reduction in ineffective heat generation by the moderator further optimizes the heat dissipation capacity of the cold pack. Moreover, due to the simplified structure of the cold pack cavity 2, the flow resistance during the moderator and coolant circulation process is reduced, the flow of moderator and coolant is smoother, and the flow-induced vibration during circulation is also reduced, further improving the reliability of the cold neutron source during long-term service.

[0037] According to another aspect of the present invention, a reactor-based cold neutron source is provided, comprising a vacuum cylinder, a neutron conduit, a heat exchange device, and a cold pack. The cold pack and the heat exchange device are placed inside the vacuum cylinder, wherein the cold pack is a simplified neutron source cold pack provided in any of the foregoing embodiments. This reactor-based cold neutron source uses liquid hydrogen or deuterium as a moderator and cryogenic helium as a coolant. A circulation pipeline is established between the heat exchange device and the cold pack. The coolant flows from outside the reactor into the cooling device for heat exchange and then flows out of the reactor. The moderator flowing out of the cold pack undergoes sufficient heat exchange with the coolant in the cooling device, and after cooling, flows back to the cold pack, thereby ensuring that the cold pack is in a stable cryogenic state. Thermal neutrons are cooled into cold neutrons by the moderator in the cold pack, and are subsequently collected by the neutron conduit and output outside the reactor for use in various neutron experiments utilizing the cold neutron source, such as neutron diffraction.

[0038] Another embodiment of the present invention provides a reactor in which one or more reactor-based cold neutron sources are provided, wherein the reactor-based cold neutron sources are the reactor-based cold neutron sources provided in any of the foregoing embodiments.

[0039] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, optimization or equivalent substitution of the technical features involved, as well as combination of implementation methods in different embodiments without causing structural and principle conflicts, all fall within the protection scope of the present invention.

Claims

1. A simplified structure of a neutron source cold blanket, comprising a moderator input pipe, a moderator output pipe, a cold blanket cavity and a coolant circulation pipeline, the cold blanket cavity being connected between the moderator input pipe and the moderator output pipe, characterized in that, the moderator input pipe comprises an inflow section and a reflux section, the inflow section being arranged in parallel with the moderator output pipe, and the reflux section being arranged in a curve relative to the inflow section; the cold blanket cavity is connected with the reflux section, the cross-sectional area of the cold blanket cavity is larger than that of the moderator input pipe and the moderator output pipe, the largest cross section of the cold blanket cavity covers the azimuthal interval where the neutron guide tube is arranged; the cold blanket cavity comprises an upper connecting section, a lower connecting section and a middle section, wherein the upper connecting section and the lower connecting section have a gradually changing cross-sectional area, and the upper connecting section protrudes towards the inflow section; the cross section of the middle section is a sector arranged around the inflow section; the coolant circulation pipeline comprises an input interlayer, an output interlayer and a cold blanket cavity interlayer, the input interlayer is arranged as an interlayer sleeve surrounding the moderator input pipe, the output interlayer is arranged as an interlayer sleeve surrounding the moderator output pipe, and the cold blanket cavity interlayer is arranged as an interlayer cavity surrounding the cold blanket; the cold blanket cavity interlayer and the input interlayer are separated by a vacuum space; the input interlayer and the cross section of the moderator input pipe are in a concentric circle structure, and the output interlayer and the cross section of the moderator output pipe are in a concentric circle structure; the reflux section is connected to the bottom of the cold blanket cavity, and the moderator output pipe is connected to the top of the cold blanket cavity.

2. A reactor-based cold neutron source disposed within a reactor comprising a cold enclosure, characterized in that, The cold blanket is configured as the simplified structure of the neutron source cold blanket according to claim 1.

3. The pile-based cold neutron source of claim 2, wherein, The reactor-based cold neutron source uses liquid hydrogen or deuterium as the moderator and helium gas as the coolant.

4. A reactor comprising a reactor-based cold neutron source, characterized in that, The reactor-based cold neutron source is configured as the reactor-based cold neutron source according to claim 2 or 3. The reactor-based cold neutron source is configured as the reactor-based cold neutron source according to claim 2 or 3.

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