Passive reactivity control system and nuclear reactor
By setting up a non-active reactive control system with shutdown channels and unidirectional flow channels in the core of a small nuclear reactor, the problem of large space occupancy of traditional control methods is solved, and a higher space utilization and dense layout are achieved.
Patent Information
- Application Number
- CN202311865989.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-07-01
AI Technical Summary
The core volume of small nuclear reactors is limited, and the use of traditional control rods or control drums takes up a large space and complex structure, which is not conducive to the dense arrangement of the core.
A non-active reactive control system is designed to control the reactivity and reaction temperature by setting a shutdown channel and a one-way flow channel in the core, and the first one-way flow channel and the second one-way flow channel are used to flow the neutron absorber into or out of the shutdown channel.
There is no need to set up a driving mechanism for controlling rods or control drums, the space occupancy is small and the structure is simple, which improves the space utilization and dense arrangement ability of the core, and reduces the axial length of the core.
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Figure CN120236790A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of nuclear power, and in particular to a passive reactivity control system and a nuclear reactor. Background Art
[0002] A nuclear reactor is a device that initiates, controls, and sustains a nuclear fission or nuclear fusion chain reaction. Controlling reactivity is one of the three key elements for the safety of a nuclear reactor. In related technologies, in order to ensure the control of reactivity, in addition to requiring that the reactivity feedback coefficient of the nuclear reactor must be negative, a shutdown system such as control rods or control drums is also provided. And the nuclear safety regulation HAF102 requires that the reactor shutdown means must consist of at least two diverse and independent systems.
[0003] Due to the limited volume of the core of a small and micro reactor, it is necessary to ensure the densification arrangement of fuel and the like in the core as much as possible. However, the traditional shutdown methods such as control rods or control drums need to be driven by relevant driving mechanisms, which have a complex structure and require a large space in the core, being unfavorable for the densification arrangement of the core. Summary of the Invention
[0004] The present invention aims to solve at least one of the technical problems in the related technologies to some extent. For this purpose, an embodiment of the present invention provides a passive reactivity control system.
[0005] The passive reactivity control system according to an embodiment of the present invention includes: a housing; a core, the core is arranged in the housing, and a neutron absorber cavity is defined by a spaced arrangement between the core and the housing. The neutron absorber cavity is filled with a neutron absorber. At least one shutdown channel and a plurality of one-way flow channels are provided in the core. The one-way flow channels include a first one-way flow channel and a second one-way flow channel. The first one-way flow channel communicates the neutron absorber cavity and the shutdown channel and allows the neutron absorber to flow into the shutdown channel to control reactivity. The second one-way flow channel communicates the neutron absorber cavity and the shutdown channel and allows the neutron absorber to flow into the neutron absorber cavity.
[0006] The passive reactivity control system according to an embodiment of the present invention is provided with a shutdown channel and one-way flow channels in the core. Among them, the first one-way flow channel only allows the neutron absorber to flow into the shutdown channel, thereby controlling reactivity. The second one-way flow channel only allows the neutron absorber to flow out of the shutdown channel, thereby increasing reactivity. By using the first one-way flow channel and the second one-way flow channel, the reactivity and reaction temperature in the core can be controlled within a preset range. There is no need to provide control rods or control drums to control reactivity, nor is it necessary to provide a driving mechanism for driving the control rods or control drums. It has a small space occupation and a simple structure, improves the space utilization rate of the core, greatly reduces the axial length of the core, and is favorable for the densification arrangement of the core.
[0007] In some embodiments, a first temperature control switch is provided on the first one-way flow channel, and a second temperature control switch is provided on the second one-way flow channel. When the reaction temperature of the reactor core is lower than the maximum reaction temperature threshold and higher than the minimum reaction temperature threshold, each of the first temperature control switch and the second temperature control switch is closed. When the reaction temperature of the reactor core is higher than the maximum reaction temperature threshold, the first temperature control switch is opened and the second temperature control switch is closed. When the reaction temperature in the reactor core is lower than the minimum reaction temperature threshold, the second temperature control switch is opened and the first temperature control switch is closed.
[0008] In some embodiments, the first temperature control switch includes a first switch valve and a first switch material. The first switch valve moves between a closed position and an open position. When the reaction temperature is higher than the maximum reaction temperature threshold, the first switch material thermally expands to push the first switch valve from the closed position to the open position. The second temperature control switch includes a second switch valve and a second switch material. The second switch valve moves between a closed position and an open position. When the reaction temperature is higher than the minimum reaction temperature threshold, the second switch material thermally expands to push the second switch valve from the open position to the closed position.
[0009] In some embodiments, the first switch material and / or the second switch material includes magnesium oxide.
[0010] In some embodiments, there are multiple first one-way flow channels and multiple second one-way flow channels. The reactor core has a first flow channel layer and a second flow channel layer spaced apart axially. The multiple first one-way flow channels are provided in the first flow channel layer, and the multiple second one-way flow channels are provided in the second flow channel layer.
[0011] In some embodiments, there are multiple first one-way flow channels and multiple second one-way flow channels. The reactor core has multiple first flow channel layers and multiple second flow channel layers spaced apart axially. Multiple first one-way flow channels are distributed in the first flow channel layer, and multiple second one-way flow channels are distributed in the second flow channel layer.
[0012] In some embodiments, the first flow channel layer and the second flow channel layer are alternately arranged axially in the reactor core.
[0013] In some embodiments, the shutdown channel extends along the central axis of the reactor core. The multiple first one-way flow channels distributed in the first flow channel layer are arranged radially around the shutdown channel and are symmetric about the center of the shutdown channel. The multiple second one-way flow channels distributed in the second flow channel layer are arranged radially around the shutdown channel and are symmetric about the center of the shutdown channel.
[0014] In some embodiments, there are multiple first one-way flow channels and multiple second one-way flow channels. The core has at least one flow channel layer spaced axially therein, and multiple first one-way flow channels and multiple second one-way flow channels are distributed in each flow channel layer.
[0015] In some embodiments, multiple shutdown channels are provided in the core, and each shutdown channel corresponds to and communicates with at least one first one-way flow channel and at least one second one-way flow channel.
[0016] In some embodiments, the shutdown channels extend along the axial direction of the core; and / or, the extension direction of the one-way flow channels is orthogonal to the axial direction of the core; and / or, the one-way flow channels are Tesla valves.
[0017] The nuclear reactor according to an embodiment of the present invention includes the passive reactivity control system according to any one of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is a front view of the passive reactivity control system according to an embodiment of the present invention.
[0019] Figure 2 is a cross-section of the passive reactivity control system according to an embodiment of the present invention Figure 1 .
[0020] Figure 3 is a cross-section of the passive reactivity control system according to an embodiment of the present invention Figure 2 .
[0021] Figure 4 is a cross-sectional schematic view of the passive reactivity control system according to another embodiment of the present invention.
[0022] Figure 5 is a schematic view of the first temperature control switch according to an embodiment of the present invention.
[0023] Figure 6 is another schematic view of the first temperature control switch according to an embodiment of the present invention.
[0024] REFERENCE SIGNS:
[0025] housing 1, core 2, neutron absorber cavity 21, shutdown channel 22, one-way flow channel 3, first one-way flow channel 31, second one-way flow channel 32, first switching valve 41, first switching material 42, first push rod 43. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.
[0027] The following describes the passive reactivity control system according to Figures 1 - 6 the embodiments of the present invention. The passive reactivity control system includes a housing 1 and a core 2. The core 2 is disposed within the housing 1, and there is a gap between the core 2 and the housing 1, forming a neutron absorber cavity 21. The neutron absorber cavity 21 is filled with a neutron absorber, that is, a neutron absorber is arranged around the core 2, and the neutron absorber has fluidity.
[0028] At least one shutdown channel 22 and a plurality of one-way flow channels 3 are provided in the core 2. The one-way flow channels 3 include a first one-way flow channel 31 and a second one-way flow channel 32. The first one-way flow channel 31 communicates the neutron absorber cavity 21 and the shutdown channel 22 and allows the neutron absorber to flow into the shutdown channel 22 to control reactivity. In other words, the first one-way flow channel 31 defines that the neutron absorber can only flow from the neutron absorber cavity 21 into the shutdown channel 22, and prohibits the neutron absorber from flowing from the shutdown channel 22 to the neutron absorber cavity 21. When the neutron absorber flows into the shutdown channel 22 along the first one-way flow channel 31, the neutron absorber in the shutdown channel 22 absorbs neutrons in the core 2, which can control the reactivity of the core 2 and avoid the reaction temperature in the core 2 from being too high.
[0029] The second one-way flow channel 32 communicates the neutron absorber cavity 21 and the shutdown channel 22 and allows the neutron absorber to flow into the neutron absorber cavity 21. In other words, the second one-way flow channel 32 defines that the neutron absorber can only flow from the shutdown channel 22 to the neutron absorber cavity 21, and prohibits the neutron absorber from flowing from the neutron absorber cavity 21 to the shutdown channel 22. When the neutron absorber flows out of the shutdown channel 22 along the second one-way flow channel 32, the reactivity of the core 2 is increased, promoting the nuclear reaction in the core 2.
[0030] In the passive reactivity control system according to the embodiments of the present invention, a shutdown channel and one-way flow channels are provided in the core. The first one-way flow channel only allows the neutron absorber to flow into the shutdown channel, thereby controlling reactivity. The second one-way flow channel only allows the neutron absorber to flow out of the shutdown channel, thereby increasing reactivity. By using the first one-way flow channel and the second one-way flow channel, the reactivity and reaction temperature in the core can be controlled within a preset range. There is no need to provide control rods or control drums to control reactivity, nor is there a need to provide a drive mechanism for driving the control rods or control drums. It occupies less space, has a simple structure, improves the space utilization rate of the core, greatly reduces the axial length of the core, and is conducive to the dense arrangement of the core.
[0031] In some embodiments, there are multiple first one-way flow channels 31 and multiple second one-way flow channels 32. The core 2 has a first flow channel layer and a second flow channel layer that are spaced apart axially. The multiple first one-way flow channels 31 are arranged in the first flow channel layer 31, and the multiple second one-way flow channels 32 are arranged in the second flow channel layer. The first one-way flow channels 31 and the second one-way flow channels 32 are distributed in different flow channel layers of the core 2. Even if the angle of the core 2 changes, the flow of the neutron absorber in the first one-way flow channels 31 and the second one-way flow channels 32 will not be significantly different due to the gravitational force, which affects the control of reactivity.
[0032] In some embodiments, as Figure 1 shown, there are multiple first one-way flow channels 31 and multiple second one-way flow channels 32. The core 2 has multiple first flow channel layers and multiple second flow channel layers that are spaced apart axially. Multiple first one-way flow channels 31 are distributed in the first flow channel layer, and multiple second one-way flow channels 32 are distributed in the second flow channel layer. The first one-way flow channels 31 and the second one-way flow channels 32 are distributed in different flow channel layers of the core 2, and moreover, the multiple first one-way flow channels 31 are divided into multiple groups and are respectively distributed in the multiple first flow channel layers, and the multiple second one-way flow channels 32 are divided into multiple groups and are respectively distributed in the multiple second flow channel layers.
[0033] Preferably, as Figure 1 shown, the first flow channel layer and the second flow channel layer are alternately arranged axially in the core 2.
[0034] Preferably, the arrangement angle and the set number of the first one-way flow channels 31 in the first flow channel layer are the same as the arrangement angle and the set number of the second one-way flow 32 in the second flow channel layer.
[0035] In some embodiments, as Figure 4 shown, there are multiple first one-way flow channels 31 and multiple second one-way flow channels 32. The core 2 has at least one flow channel layer that is spaced apart axially, and multiple first one-way flow channels 31 and multiple second one-way flow channels 32 are distributed in each flow channel layer.
[0036] Optionally, as Figure 1 shown, the shutdown channel 22 extends axially along the core 2.
[0037] Optionally, as Figure 1 shown, the extension direction of the one-way flow channel 3 is orthogonal to the axial direction of the core 2.
[0038] Optionally, the one-way flow channel 3 is a Tesla valve, and the Tesla valve can achieve the one-way flow of the fluid. For example, as Figure 2 shown, the first one-way flow channel 31 is a first Tesla valve, and the neutron absorber in the neutron absorber cavity 21 enters the shutdown channel 22 through the first Tesla valve. As Figure 3As shown, the second unidirectional flow channel 32 is a second Tesla valve, and the neutron absorber in the shutdown channel 22 is discharged outward through the second Tesla valve and into the neutron absorber cavity 21.
[0039] In some embodiments, a first temperature control switch (not shown in the figure) is provided on the first unidirectional flow channel 31, and a second temperature control switch (not shown in the figure) is provided on the second unidirectional flow channel 32. When the reaction temperature of the reactor core 2 is lower than the maximum reaction temperature threshold and higher than the minimum reaction temperature threshold, that is, when the reaction temperature in the reactor core 2 is within the normal range, it indicates that the reactivity in the reactor core 2 is within the normal range. Each of the first temperature control switch and the second temperature control switch is closed, and the neutron absorber cannot flow into the shutdown channel 22 along the first unidirectional flow channel 31, nor can it flow out of the shutdown channel 22 along the second unidirectional flow channel 21. That is, there is no need for the neutron absorber to adjust the reactivity of the reactor core 2.
[0040] When the reaction temperature of the reactor core 2 is higher than the maximum reaction temperature threshold, the reactivity of the reactor core 2 is too strong, causing the first temperature control switch to open and the second temperature control switch to close. The neutron absorber flows into the shutdown channel 22 along the first unidirectional flow channel 31 to control the reactivity of the reactor core 2 and thereby reduce the reaction temperature.
[0041] When the reaction temperature in the reactor core 2 is lower than the minimum reaction temperature threshold, the reactivity of the reactor core 2 is insufficient, causing the second temperature control switch to open and the first temperature control switch to close. The neutron absorber flows out of the shutdown channel 22 along the second unidirectional flow channel 21 to increase the reactivity of the reactor core 2 and thereby increase the reaction temperature.
[0042] In some embodiments, as Figure 5 and Figure 6 shown, the first temperature control switch includes a first switch valve 41 and a first switch material 42. The first switch valve 41 moves between a closed position and an open position. When the reaction temperature is lower than the maximum reaction temperature threshold, the first switch valve 41 is in the closed position, and at this time the first temperature control switch is closed, and the neutron absorber cannot flow through the first unidirectional flow channel 31. When the reaction temperature is higher than the maximum reaction temperature threshold, the first switch material 42 thermally expands to push the first switch valve 41 from the closed position to the open position, and the first temperature control switch opens. The neutron absorber flows into the shutdown channel 22 of the reactor core 2 through the first unidirectional flow channel 31 to control the reactivity and thereby reduce the reaction temperature in the reactor core 2. And there is no need to use other driving mechanisms and control mechanisms to control the opening and closing of the first temperature control switch, with a simple structure and small occupied space.
[0043] It can be understood that during the process of the first switch valve 41 moving from the closed position to the open position, the opening degree of the first temperature control switch gradually changes from 0 to 1. For example, Figure 5 the opening degree of the first temperature control switch shown is smaller than Figure 6 the opening degree of the first temperature control switch shown.
[0044] Specifically, as Figure 5 and Figure 6 shown, the first temperature control switch has a cavity for accommodating the first switching material 42, the first switching material 42 is filled in the cavity, the first temperature control switch further includes a first push rod 43, one end of the first push rod 43 is connected to the first switching valve 41, and the other end of the first push rod 43 extends into the first switching material 42. When the first switching material 42 expands due to heat, the first switching material 42 pushes the first push rod 43 outwards, and then the first push rod 43 pushes the first switching valve 41 towards the open position. Moreover, the higher the reaction temperature in the reactor core 2, the greater the expansion degree of the first switching material 42, the greater the distance that the first push rod 43 pushes the first switching valve 41, the greater the opening degree of the first temperature control switch, and the greater the flow rate of the neutron absorber in the first one-way flow channel 31. Thus, the reactivity in the reactor core 2 can be quickly controlled, and the reactivity of the reactor core 2 can be reduced to a reasonable range. When the reaction temperature in the reactor core 2 drops below the maximum reaction temperature threshold, the first switching material 42 contracts, the first push rod 43 retracts, driving the first switching valve 41 towards the closed position, and the first temperature control switch closes. Therefore, the first temperature control switch provided by the embodiment of the present invention has the characteristic of being reusable.
[0045] In some embodiments, the second temperature control switch may include a second switching valve and a second switching material. The second switching valve moves between a closed position and an open position. When the reaction temperature is lower than the minimum reaction temperature threshold, the second switching valve is in the open position. At this time, the second temperature control switch is open, and the neutron absorber flows through the second one-way flow channel 32 and flows out of the shutdown channel 22 to increase the reactivity in the reactor core 2. When the reaction temperature is higher than the minimum reaction temperature threshold, the second switching material thermally expands to push the second switching valve from the open position to the closed position, and the second temperature control switch closes. The neutron absorber stops discharging outwards. In this embodiment, there is no need to adopt other driving mechanisms and control mechanisms to control the opening and closing of the second temperature control switch. The second temperature control switch has a simple structure and occupies a small space.
[0046] In some alternative embodiments, the first switching material 42 and / or the second switching material includes magnesium oxide.
[0047] It can be understood that by adding nanomaterials or other filling materials, the corresponding relationship between the thermal expansion coefficient of magnesium oxide and temperature can be changed. Thus, the first switching material and the second switching material can have specific expansion degrees at specific temperatures, so as to realize the start and stop of the first temperature control switch and the second temperature control switch in different temperature ranges.
[0048] Next, according to Figures 1 - 4 describe the passive reactivity control system in several specific examples of the present invention.
[0049] In some examples, as Figures 1 - 3As shown, the core 2 is a horizontally placed core, that is, its axis extends in the horizontal direction. A shutdown channel 22 is provided in the core 2, and the shutdown channel 22 extends along the central axis of the core 2. The core 2 has two first flow channel layers and a plurality of second flow channel layers that are spaced apart in its axial direction, and the first flow channel layers and the second flow channel layers are alternately arranged in the axial direction of the core 2 to make the flow channel arrangement more balanced.
[0050] As Figure 2 shown, six first one-way flow channels 31 are distributed in each first flow channel layer. Moreover, the six first one-way flow channels 31 distributed in the first flow channel layer are arranged radially around the shutdown channel 22 and are centrosymmetric with respect to the center of the shutdown channel 22.
[0051] As Figure 3 shown, six second one-way flow channels 32 are distributed in each second flow channel layer. Moreover, the six second one-way flow channels 32 distributed in the second flow channel layer are arranged radially around the shutdown channel 22 and are centrosymmetric with respect to the center of the shutdown channel 22.
[0052] Such an arrangement makes the distribution of the first one-way flow channels 31 and the second one-way flow channels 32 in the core 2 more balanced, ensuring the smooth flow of the neutron absorber. Even if the core 2 rotates, the neutron absorber can still flow along at least part of the first one-way flow channels 31 and at least part of the second one-way flow channels 32 under the action of gravity to control the reactivity of the core 2.
[0053] Specifically, since the core 2 is horizontally placed, when the first one-way flow channel 31 is opened, the neutron absorber may not be able to flow into the shutdown channel 22 from some of the first one-way flow channels 31 located below the shutdown channel 22 due to the action of gravity. However, the first one-way flow channels 31 located above the shutdown channel 22 are not affected and the neutron absorber can flow into the shutdown channel 22 smoothly through these first one-way flow channels 31. If the core 2 rotates, the effective first one-way flow channels 31 will change. However, since the first one-way flow channels 31 in the first flow channel layer are arranged radially, no matter how much the core 2 rotates, it can still ensure that the neutron absorber flows along the first one-way flow channels 31 located above the shutdown channel 22 under the action of gravity.
[0054] Since the core 2 is horizontally placed, when the second one-way flow channel 32 is opened, the neutron absorber may not be able to flow out of the shutdown channel 22 from some of the second one-way flow channels 32 located above the shutdown channel 22 due to the action of gravity. However, the first one-way flow channels 31 located below the shutdown channel 22 are not affected and the neutron absorber can flow out of the shutdown channel 22 smoothly through these second one-way flow channels 32. If the core 2 rotates, the effective second one-way flow channels 32 will change. However, since the second one-way flow channels 32 in the second flow channel layer are arranged radially, no matter how much the core 2 rotates, it can still ensure that the neutron absorber flows along the first one-way flow channels 31 located below the shutdown channel 22 under the action of gravity.
[0055] Therefore, the passive reactivity control system of this example has a stable reactivity control function.
[0056] In some examples, a shutdown channel 22 is provided in the core 2, and the shutdown channel 22 extends along the central axis of the core 2. The core 2 has a plurality of flow channel layers arranged at intervals in its axial direction, and as Figure 4 shown, three first one-way flow channels 31 and three second one-way flow channels 32 are distributed in each flow channel layer. The three first one-way flow channels 31 and the three second one-way flow channels 32 are arranged at intervals around the shutdown channel 22 and are radially arranged, and the first one-way flow channels 31 and the second one-way flow channels 32 are alternately arranged in the circumferential direction of the shutdown channel 22. Such an arrangement can enable the neutron absorber to flow along at least part of the first one-way flow channels 31 and at least part of the second one-way flow channels, so that the passive reactivity control system has a stable reactivity control function.
[0057] In some other alternative embodiments, a plurality of shutdown channels 22 are provided in the core 2, and the shutdown channels 22 extend along the axial direction of the core 2. Each shutdown channel 22 corresponds to and communicates with at least one first one-way flow channel 31 and at least one second one-way flow channel 32.
[0058] The nuclear reactor of the embodiment of the present invention includes the passive reactivity control system of any one of the above embodiments.
[0059] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0060] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.
[0061] In the present invention, unless otherwise clearly specified or limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0062] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0063] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.
[0064] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.
Claims
1. A passive reactivity control system, characterized in that, Comprising: A housing; A core, which is arranged inside the housing. A neutron absorber cavity is defined by a spaced arrangement between the core and the housing. The neutron absorber cavity is filled with a neutron absorber. At least one shutdown channel and a plurality of one-way flow channels are provided in the core. The one-way flow channels include a first one-way flow channel and a second one-way flow channel. The first one-way flow channel communicates with the neutron absorber cavity and the shutdown channel and allows the neutron absorber to flow into the shutdown channel to control reactivity. The second one-way flow channel communicates with the neutron absorber cavity and the shutdown channel and allows the neutron absorber to flow into the neutron absorber cavity.
2. The passive reactivity control system according to claim 1, wherein A first temperature control switch is provided on the first one-way flow channel, and a second temperature control switch is provided on the second one-way flow channel. When the reaction temperature of the core is lower than the maximum reaction temperature threshold and higher than the minimum reaction temperature threshold, each of the first temperature control switch and the second temperature control switch is closed. When the reaction temperature of the core is higher than the maximum reaction temperature threshold, the first temperature control switch is opened and the second temperature control switch is closed. When the reaction temperature in the core is lower than the minimum reaction temperature threshold, the second temperature control switch is opened and the first temperature control switch is closed.
3. The passive reactivity control system according to claim 2, wherein The first temperature control switch includes a first switch valve and a first switch material. The first switch valve moves between a closed position and an open position. When the reaction temperature is higher than the maximum reaction temperature threshold, the first switch material thermally expands to push the first switch valve from the closed position to the open position; The second temperature control switch includes a second switch valve and a second switch material. The second switch valve moves between a closed position and an open position. When the reaction temperature is higher than the minimum reaction temperature threshold, the second switch material thermally expands to push the second switch valve from the open position to the closed position.
4. The passive reactivity control system according to claim 3, wherein The first switch material and / or the second switch material includes magnesium oxide.
5. The passive reactivity control system according to claim 1, wherein There are a plurality of the first one-way flow channels and a plurality of the second one-way flow channels. The core has a first flow channel layer and a second flow channel layer spaced axially therefrom. A plurality of the first one-way flow channels are provided in the first flow channel layer, and a plurality of the second one-way flow channels are provided in the second flow channel layer.
6. The passive reactivity control system according to claim 1, wherein There are a plurality of the first one-way flow channels and a plurality of the second one-way flow channels. The core has a plurality of first flow channel layers and a plurality of second flow channel layers spaced axially therefrom. A plurality of the first one-way flow channels are distributed in the first flow channel layer, and a plurality of the second one-way flow channels are distributed in the second flow channel layer.
7. The passive reactivity control system according to claim 6, wherein The first flow channel layer and the second flow channel layer are alternately arranged in the axial direction of the core.
8. The passive reactivity control system according to any one of claims 5-7, characterized in that The shutdown channel extends along the central axis of the core; A plurality of the first one-way flow channels distributed in the first flow channel layer are arranged radially around the shutdown channel and are symmetric about the center of the shutdown channel; A plurality of the second one-way flow channels distributed in the second flow channel layer are arranged radially around the shutdown channel and are symmetric about the center of the shutdown channel.
9. The passive reactivity control system according to claim 1, characterized in that There are a plurality of the first one-way flow channels and a plurality of the second one-way flow channels. The core has at least one flow channel layer arranged at intervals in its axial direction, and a plurality of the first one-way flow channels and a plurality of the second one-way flow channels are distributed in each flow channel layer.
10. The passive reactivity control system according to claim 1, characterized in that A plurality of the shutdown channels are provided in the core, and each shutdown channel corresponds to and communicates with at least one of the first one-way flow channels and at least one second one-way flow channel.
11. The passive reactivity control system according to any one of claims 1-7, 9 and 10, characterized in that The shutdown channel extends along the axial direction of the core; and / or The extension direction of the one-way flow channel is orthogonal to the axial direction of the core; and / or The one-way flow channel is a Tesla valve.
12. A nuclear reactor, characterized in that, Comprising the passive reactivity control system according to any one of claims 1-11.