Shielded electromagnetic pump for nuclear reactors

Abstract

An electromagnetic pump (EMP) for a liquid metal-cooled nuclear reactor includes a pump casing, concentric inner and outer flow ducts collectively defining an annular fluid passage extending coaxially with a longitudinal axis of the EMP, and an induction coil configured to control the flow of liquid metal coolant through the annular fluid passage based on power received from a power source. At least one of the inner or outer flow ducts includes a gamma shielding material configured to block gamma rays from entering the interior of the EMP from the annular fluid passage. The pump casing can include a neutron absorbing material configured to absorb neutrons entering the pump casing from outside the EMP. The EMP can include a neutron moderator disposed on an outer surface of the pump casing and configured to slow down neutrons entering the pump casing so that they are absorbed by the neutron absorbing material.

Description

[Technical Field]

[0001] The present inventive concepts relate generally to nuclear reactors, and more particularly to electromagnetic pumps used to control the circulation of liquid metal coolant through the core of a liquid metal cooled nuclear reactor, and more particularly to providing improved protection of the electromagnetic pumps from the radiation and / or thermal aspects of the reactor's operating environment. [Background technology]

[0002] A nuclear reactor included in a nuclear reactor facility may be configured to be cooled via heat transfer to one or more coolants circulating through the reactor core. A variety of coolants may be utilized to remove heat from the reactor core. The coolant may include one or more of a variety of substances, including water, liquid metal, molten salt, gaseous substances, combinations thereof, and the like.

[0003] In some nuclear reactor facilities, the coolant that removes heat from the reactor core (also referred to herein as primary coolant) is circulated through a heat exchanger to transfer the heat to another coolant (also referred to herein as secondary coolant). In some cases, the secondary coolant is used to perform work, such as driving a generator by circulating it through a turbine device included in the nuclear reactor facility. In some nuclear reactor facilities, the coolant may be used to provide process heat to support one or more industrial processes, such as desalination, hydrogen production, etc.

[0004] In some cases, nuclear reactors are configured to be cooled by liquid metal circulation. Such reactors are interchangeably referred to herein as liquid-metal-cooled nuclear reactors and may include a primary coolant loop through which one or more liquid metal materials circulate as a primary coolant. Such one or more liquid metal materials circulating through the primary coolant loop may circulate at least partially through the reactor core, and are referred to herein as liquid metal coolant.

[0005] In some cases, the liquid metal coolant that may be circulated through the reactor includes an electrically conductive liquid metal material. A liquid metal-cooled reactor configured to be cooled via an electrically conductive liquid metal material may include one or more electromagnetic pumps (EMPs, also interchangeably referred to herein as EM pumps) configured to circulate the electrically conductive liquid metal coolant through the reactor. Summary of the Invention

[0006] According to some example embodiments, a nuclear reactor configured to be cooled via liquid metal circulation may include a reactor pressure vessel, a reactor core within the reactor pressure vessel, and an electromagnetic pump (EMP) within the reactor pressure vessel. The electromagnetic pump may be configured to circulate a flow of liquid metal coolant through a primary coolant flow path that includes the reactor core. The electromagnetic pump may include a pump casing having a longitudinal axis extending longitudinally, the pump casing at least partially defining an interior of the EMP, inner and outer flow ducts extending coaxially with the longitudinal axis, the inner and outer flow ducts collectively defining an annular fluid passage extending coaxially with the longitudinal axis, and a plurality of induction coils within the EMP and configured to be electrically connected to a power source, the plurality of induction coils configured to control the flow of liquid metal coolant through the primary coolant flow path via the annular fluid passage based on electrical power received from the power source. At least one of the inner flow duct or the outer flow duct may include a gamma shielding material configured to block gamma rays from entering the interior of the EMP from the annular fluid passage.

[0007] The at least one flow duct may include concentric cylindrical duct walls defining a duct annulus therebetween, and a gamma shielding material is disposed within the duct annulus.

[0008] At least one flow duct may include a material that at least partially defines an inner surface or an outer diameter surface of the annular fluid passage, the material including a gamma shielding material.

[0009] Each of the inner and outer flow ducts may include gamma shielding material.

[0010] The pump casing may include a neutron absorbing material configured to absorb neutrons entering the pump casing from outside the EMP.

[0011] The pump casing may include concentric cylindrical casing walls defining a casing annulus therebetween. The neutron absorbing material may be disposed within the casing annulus.

[0012] The EMP may further include a neutron moderator on an outer surface of the pump casing, the neutron moderator may be configured to moderate neutrons received from outside the EMP such that neutrons entering the pump casing from outside the EMP are moderated neutrons, and the neutron absorbing material may be configured to absorb the moderated neutrons.

[0013] The nuclear reactor may further include a control system configured to control a power source to control the supply of power to the EMP to control the flow of liquid metal coolant through the primary coolant flow path.

[0014] The plurality of induction coils may include at least one of an inner induction coil located within a central region defined at least in part by the inner surface of the inner flow duct, or an outer induction coil located within an annular region defined at least in part between the outer surface of the outer flow duct and the inner surface of the pump casing.

[0015] According to some demonstrative embodiments, an electromagnetic pump (EMP) may include a pump casing having a longitudinal axis extending longitudinally and at least partially defining an interior of the EMP, concentric inner and outer flow ducts extending coaxially with the longitudinal axis and collectively defining an annular fluid passage extending coaxially with the longitudinal axis, and a plurality of induction coils within the EMP configured to be electrically connected to a power source, the plurality of induction coils configured to control flow of liquid metal coolant through the annular fluid passage based on power received from the power source. At least one of the inner or outer flow ducts may include gamma shielding material configured to block gamma radiation from entering the interior of the EMP from the annular fluid passage.

[0016] The at least one flow duct may include concentric cylindrical duct walls defining a duct annulus between the concentric cylindrical duct walls, and a gamma shielding material disposed within the duct annulus.

[0017] The at least one flow duct may include a material that at least partially defines an inner surface or an outer diameter surface of the annular fluid passage. The material may include a gamma shielding material.

[0018] Each of the inner and outer flow ducts may include gamma shielding material.

[0019] The pump casing may include a neutron absorbing material configured to absorb neutrons entering the pump casing from outside the electromagnetic pump.

[0020] The pump casing may include concentric cylindrical housing walls defining a housing annulus therebetween. The neutron absorbing material may be disposed within the housing annulus.

[0021] The EMP may further include a neutron moderator on an outer surface of the pump casing, the neutron moderator may be configured to moderate neutrons received from outside the EMP such that neutrons entering the pump casing from outside the EMP are moderated neutrons, and the neutron absorbing material may be configured to absorb the moderated neutrons.

[0022] The plurality of induction coils may include at least one of an inner induction coil located within a central region defined at least in part by the inner surface of the inner flow duct, or an outer induction coil located within an annular region defined at least in part between the outer surface of the outer flow duct and the inner surface of the pump casing.

[0023] According to some example embodiments, a method of operating an EMP may include controlling a power supply to the EMP to generate one or more magnetic fields in a plurality of induction coils to induce a flow of liquid metal coolant through an annular fluid passage, and blocking, at a gamma shielding material included in at least one flow duct, gamma rays emitted from the liquid metal coolant located in the annular fluid passage from entering an interior of the EMP outside the annular fluid passage.

[0024] The pump casing may include a neutron absorbing material configured to absorb neutrons entering the pump casing from outside the EMP, and the method may further include absorbing neutrons received at the pump casing from outside the EMP with the neutron absorbing material.

[0025] According to some example embodiments, a method of configuring a nuclear reactor to improve flow control of liquid metal coolant within the reactor may include installing an electromagnetic pump (EMP) in a primary coolant loop within reactor pressure of the nuclear reactor. The EMP includes: a pump casing having a longitudinal axis extending longitudinally, the pump casing at least partially defining an interior of the EMP; inner and outer flow ducts extending coaxially with the longitudinal axis, the inner and outer flow ducts collectively defining an annular fluid passage extending coaxially with the longitudinal axis; and a plurality of induction coils within the interior of the EMP and configured to be electrically connected to a power source, the plurality of induction coils configured to control the flow of liquid metal coolant through the annular fluid passage based on power received from the power source, and at least one of the inner or outer flow ducts including gamma shielding material configured to block gamma radiation from entering the interior of the EMP from the annular fluid passage. The method may include electrically connecting the EMP to a power source via a power cable and communicatively coupling the EMP to a control system, the control system including a memory storing a program of instructions and a processor configured to execute the program of instructions to control a flow of liquid metal coolant through the primary coolant loop based on controlling a supply of electrical power provided to the EMP from the power source. [Brief explanation of the drawings]

[0026] Various features and advantages of the non-limiting embodiments herein will become more apparent from a consideration of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for illustrative purposes only and should not be construed as limiting the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Various dimensions of the drawings may be exaggerated for clarity.

[0027] [Figure 1] FIG. 1 is a schematic diagram of a nuclear reactor facility including a liquid metal cooled nuclear reactor and at least one EM pump, according to some example embodiments. [Figure 2A] FIG. 2A is a perspective view of a liquid metal cooled nuclear reactor according to some example embodiments. [Figure 2B] FIG. 2B is a plan view of a liquid metal cooled nuclear reactor according to some example embodiments. [Figure 3A] FIG. 3A is a perspective view of an EM pump (EMP) according to some exemplary embodiments. [Figure 3B] FIG. 3B is a perspective cross-sectional view taken along cross-sectional line IIIB-IIIB' shown in FIG. 3A, according to some exemplary embodiments. [Figure 4A] FIG. 4A is a cross-sectional view of the EMP of FIG. 3A taken along cross-sectional line IVA-IVA′ shown in FIG. 3A, according to some example embodiments. [Figure 4B] FIG. 4B is a cross-sectional view of the EMP of FIG. 4A taken along cross-sectional line IVB-IVB′ shown in FIG. 3A, according to some exemplary embodiments. [Figure 4C] FIG. 4C is a cross-sectional view of the EMP of FIG. 4A taken along the cross-sectional line IVC-IVC′ shown in FIG. 3A, according to some example embodiments. [Figure 4D] FIG. 4D is a cross-sectional view of the EMP of FIG. 3A taken along the cross-sectional line IVA-IVA′ shown in FIG. 3A, according to some example embodiments. [Figure 5] FIG. 5 is a flowchart illustrating a method of arming an EMP, according to some example embodiments. [Figure 6] FIG. 6 is a flow chart illustrating a method for configuring a nuclear reactor to improve the reliability and protection of liquid metal coolant flow control within the nuclear reactor, according to some example embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0028] Reference will now be made in detail to exemplary embodiments, some of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

[0029] When an element or layer is referred to as being "on," "connected to," "coupled to," or "covering" another element or layer, it should be understood that it may be directly connected to, coupled to, or covering the other element or layer, or that intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout this specification. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] Although terms such as first, second, and third may be used herein to describe various elements, components, regions, layers, and / or sections, it should be understood that these elements, components, regions, layers, and / or sections are not limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section described below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0031] Spatially relative terms (e.g., "beneath," "below," "lower," "above," "upper," etc.) may be used herein to describe the relationship of one element or feature to another element or feature, as illustrated in the figures, for ease of description. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures were turned over, elements described as "below" or "beneath" other elements or features would be oriented "above" the other elements or features. Thus, the term "below" may encompass both an orientation of above and below. The device may be in other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein would be interpreted accordingly.

[0032] The terminology used herein is for the purpose of describing various embodiments only and is not intended to limit example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that as used herein, the terms "includes," "including," "comprises," and / or "comprising" specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0033] Exemplary embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of exemplary embodiments. As such, variations from the shapes depicted are to be expected as a result, for example, of manufacturing techniques and / or tolerances. Accordingly, the exemplary embodiments should not be construed as limited to the shapes of regions depicted herein and are intended to include, for example, deviations in shape due to manufacturing. For example, an embedded region depicted as a rectangle typically has rounded or curved features and / or a gradient of embedded concentration at its edges, rather than a binary transition from embedded to unembedded. Similarly, a buried region formed by implantation may result in some embedding in the region between the embedded region and the surface into which the implantation occurs. Thus, the regions illustrated in the figures are schematic in nature, and the shapes are not intended to illustrate the actual shape of the region of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0034] Exemplary embodiments may be described with reference to acts and symbolic representations (e.g., in the form of flowcharts, flow diagrams, data flow diagrams, structure diagrams, block diagrams, etc.) of operations that may be performed in combination with the units and / or devices discussed in more detail below. Although described in a particular manner, a function or operation specified in a particular block may be executed differently from the flow specified in the flowchart, flow diagram, etc. For example, functions or operations illustrated as being executed sequentially in two consecutive blocks may actually be executed concurrently or may be executed in the reverse order, in some cases.

[0035] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments belong. Furthermore, terms, including those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless expressly defined as such in this specification.

[0036] The units, systems, and / or devices according to some exemplary embodiments may be implemented using one or more examples of hardware, software, and / or combinations thereof. For example, a hardware device may be implemented using processing circuitry such as, but not limited to, a processor, central processing unit (CPU), controller, arithmetic logic unit (ALU), digital signal processor, microcomputer, field programmable gate array (FPGA), system on chip (SoC), programmable logic unit, microprocessor, or any other device capable of responding to and executing instructions in a defined manner.

[0037] Software may include computer programs, program code, instructions, or combinations thereof, for independently or collectively instructing or configuring hardware devices to operate in a desired manner. Computer programs and / or program code may include programs or computer-readable instructions, software components, software modules, data files, data structures, and / or the like that may be implemented by one or more hardware devices, such as one or more of the hardware devices mentioned above. Examples of program code include both machine code produced by a compiler and higher-level program code that is executed using an interpreter.

[0038] For example, if the hardware unit is a computer processing device (e.g., a processor, a central processing unit (CPU), a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a microprocessor, etc.), the computer processing device may be configured to execute the program code by performing arithmetic operations, logical operations, and input / output operations in accordance with the program code. When the program code is loaded into the computer processing device, the computer processing device is programmed to execute the program code, thereby converting the computer processing device into a special-purpose computer processing device. In a more specific example, when the program code is loaded into a processor, the processor becomes programmed to execute the program code and its corresponding operations, thereby converting the processor into a special-purpose processor.

[0039] The software and / or data may be permanently or temporarily embodied in any type of machine, component, physical or virtual device, or computer storage medium or device that can provide instructions or data to or be interpreted by a hardware device. The software may also be distributed over network-coupled computer systems so that it is stored and executed in a distributed manner. In particular, for example, the software and data may be stored by one or more computer-readable recording media, including the tangible or non-transitory computer-readable storage media discussed herein.

[0040] According to some exemplary embodiments, a computer processing device may be described as including various functional units that perform various operations and / or functions for clarity of description. However, the computer processing device is not intended to be limited to these functional units. For example, in some exemplary embodiments, various operations and / or functions of a functional unit may be performed by other of the functional units. Furthermore, the computer processing device may perform the operations and / or functions of the various functional units without subdividing the operations and / or functions of the computer processing device into these various functional units.

[0041] The units and / or devices according to some exemplary embodiments may also include one or more storage devices. The one or more storage devices may be tangible or non-transitory computer-readable storage media, such as random access memory (RAM), read-only memory (ROM), permanent mass storage devices (such as disk drives), solid-state (e.g., NAND flash) devices, and / or any other similar data storage mechanisms capable of storing and recording data. The one or more storage devices may be configured to store computer programs, program code, instructions, or some combination thereof, for one or more operating systems and / or for implementing the exemplary embodiments described herein. The computer programs, program code, instructions, or some combination thereof may also be loaded into one or more storage devices and / or one or more computer processing devices from a separate computer-readable storage medium using a drive mechanism. Such other computer-readable storage media may include a universal serial bus (USB) flash drive, a memory stick, a Blu-ray / DVD / CD-ROM drive, a memory card, and / or other similar computer-readable storage media. A computer program, program code, instructions, or any combination thereof may be loaded into one or more storage devices and / or one or more computer processing devices from a remote data storage device via a network interface rather than via a local computer-readable storage medium. Furthermore, a computer program, program code, instructions, or any combination thereof may be loaded into one or more storage devices and / or one or more processors from a remote computing system configured to transfer and / or distribute computer programs, program code, instructions, or any combination thereof over a network.The remote computing system may transfer and / or distribute the computer program, program code, instructions, or any combination thereof via a wired interface, an air interface, and / or any other similar medium.

[0042] The one or more hardware devices, one or more storage devices, and / or computer programs, program code, instructions, or any combination thereof may be specially designed and constructed for the purposes of the exemplary embodiments, or may be known devices modified and / or modified for the purposes of the exemplary embodiments.

[0043] A hardware device, such as a computer processing device, can execute an operating system (OS) and one or more software applications that run on the OS. The computer processing device can also access, store, manipulate, process, and create data in response to the execution of software. For simplicity, some exemplary embodiments may be illustrated as a single computer processing device, but those skilled in the art will understand that a hardware device can include multiple processing elements and multiple types of processing elements. For example, a hardware device can include multiple processors, or a single processor and controller. Furthermore, other processing configurations, such as parallel processors, are possible.

[0044] Although described with reference to specific examples and figures, various modifications, additions, and substitutions of the exemplary embodiments may be made in accordance with the teachings of those skilled in the art. For example, the techniques described may be performed in an order different from that described, and / or the components of the described systems, architectures, devices, circuits, etc. may be connected or combined differently from that described, or the results may be achieved by other components or equivalents, as appropriate.

[0045] The inventive concepts relate to electromagnetic pumps (EMPs) configured to provide improved control, including increased reliability of such control, of the flow of liquid metal coolant through at least a portion of the reactor, liquid metal cooled nuclear reactors including one or more of the electromagnetic pumps, and methods of configuring and / or operating the electromagnetic pumps and / or the reactor.

[0046] An electromagnetic pump (EMP) according to some exemplary embodiments of the inventive concept can include an annular linear induction pump (ALIP). The annular linear induction pump (ALIP) can be an electromagnetic pump configured to pump liquid metal based on applying an electromagnetic force to the liquid metal coolant, causing it to flow along the length of the pump (e.g., parallel to the longitudinal axis). This can be accomplished by applying AC current at a specified AC frequency and phase angle to an induction coil of the ALIP that surrounds an annular fluid passage extending along the length of the pump (e.g., coaxial with the longitudinal axis of the pump).

[0047] In some exemplary embodiments, an EMP may be configured to provide self-cooling during operation, for example, based on rejecting heat generated within the EMP from the liquid metal coolant flowing through the EMP. In some exemplary embodiments, some or all of the heat generated by the EMP is removed from the EMP's stator to the liquid metal coolant, rather than the traditional approach of an active auxiliary cooling system located outside the reactor, as required by conventional EM pump designs. For example, the EMP may draw liquid metal coolant from a highly activated (Na-24) cold pool (e.g., the suction reservoir described herein) with an inlet temperature of approximately 350°C, resulting in a reactor having a secondary or intermediate coolant loop containing a liquid metal coolant such as sodium or lead. A self-cooled EMP may reduce, minimize, or prevent drawbacks associated with external cooling methods. Internal components of the EMP, such as electrical insulation, induction coils, and stators, are configured to withstand the harsh thermal and radiation environment within the primary coolant loop vessel.

[0048] In some exemplary embodiments, an EMP may be configured to at least partially shield some or all of its internal components from gamma rays emitted from the liquid metal coolant flowing through the EMP by including one or more gamma shielding materials, thereby providing gamma ray shielding for the EMP. In some exemplary embodiments, an EMP may be configured to shield some or all of its internal components from neutrons received from outside the EMP (e.g., ambient neutrons received from the environment surrounding the EMP) by including one or more neutron absorbing materials, thereby providing neutron exposure shielding for the EMP. For example, including one or more gamma shielding materials in one or more components of the EMP and / or including one or more neutron absorbing materials in one or more components of the EMP can reduce, minimize, or prevent wear and / or damage that the EMP may incur due to gamma rays and / or ambient neutrons entering the EMP and contacting one or more internal components of the EMP (e.g., induction coils, electrical insulation, circuits, stators, etc.). This results in improved EMP service life, increased EMP reliability, reduced EMP maintenance, and / or simplified decommissioning of the EMP due to reduced irradiation and / or activation of internal EMP components.

[0049] Furthermore, based on being configured with gamma ray shielding and / or ambient neutron shielding, the EMP can be configured to be located proximate to the reactor core within the reactor, providing improved shielding from ambient neutrons in a highly radioactive, high temperature ambient environment proximate the reactor core, and further configured with shielding from gamma rays emitted by the liquid metal coolant circulating (e.g., flowing) within the reactor, thereby improving the compactness of the reactor design. Furthermore, based on including gamma shielding materials and / or neutron absorbing materials, the EMP can be configured to reduce the likelihood of pump failure due to the effects of radiation insulation degradation, reduce the activation level of EMP components, simplify decommissioning procedures, and fully utilize the benefits of large EMPs in liquid metal-cooled reactors.

[0050] As described herein, the internal components of an EMP include a pump duct (also referred to herein as a flow duct) and a pump housing (also referred to herein as a pump casing). The flow ducts collectively define a flow duct (e.g., an annular fluid passage) configured to contain liquid metal coolant flowing therethrough. The flow ducts can each have a radial thickness to provide some structural integrity in a high-pressure system. Additionally, the flow ducts can be configured to separate the received liquid metal coolant entering the flow conduit (e.g., activated sodium) from other pump components (also referred to herein as internal components), such as the coil, stator, insulation, and nitrogen gas. Like the flow duct, the pump casing can have some radial thickness to provide some structural integrity to the EMP and allow it to be lifted and oriented in various directions. The flow duct can have a thickness sufficient to accommodate gamma shielding material as a filler material within the annulus defined by the cylindrical duct walls (e.g., stainless steel walls), for example. The pump casing, and / or its structure, may have a thickness sufficient to accommodate neutron absorbing material therein, for example, as a filler within an annulus defined by the cylindrical casing wall (e.g., a stainless steel wall).

[0051] In some exemplary embodiments, the EMP is configured to include a gamma shielding material in at least one flow conduit at least partially defining an annular fluid passage through which the liquid metal coolant flows within the EMP, thereby shielding internal components of the EMP outside the annular fluid passage from gamma rays emitted by the liquid metal coolant. The gamma shielding material may include one or more materials including, but not limited to, lead, iron and steel alloys, tin, bismuth, tungsten and its alloys, water, or one or more of borated paraffin or polyethylene. In some exemplary embodiments, the EMP is configured to include a neutron absorbing material in at least a portion of the pump casing that at least partially defines the outer surface and / or outer structure of the EMP, absorbing ambient neutrons received from the ambient environment outside the EMP and thereby reducing, minimizing, or preventing such ambient neutrons from entering the interior of the EMP to wear or damage the internal components of the EMP. The neutron absorber may include one or more materials including, but not limited to, one or more of gadolinium, cadmium, boron, boron carbide, gadolinium oxide, hafnium lithium, tantalum, europium, gadolinium stainless steel, hafnium, silver, xenon, or indium.

[0052] An EMP according to some example embodiments may include neutron absorbing material as a filler material within a space (e.g., a casing annulus) within at least a portion of the pump casing of the EMP, while employing gamma shielding material as a filler material within a space (e.g., a duct annulus) within at least one of the inner or outer flow ducts that at least partially defines an annular fluid passage through which liquid metal coolant may flow within the EMP. These neutron absorbing and gamma shielding materials, when included in the EMP, may configure the EMP to have neutron absorption characteristics at low-energy or high-energy neutron fluxes, well-characterized irradiation performance and thermophysical properties, and the ability to support a long design reactor life.

[0053] Although an EMP according to some exemplary embodiments may be included in a liquid metal cooled reactor, such as a liquid metal fast cooled reactor, an EMP according to some exemplary embodiments may be included in a variety of other environments and for other purposes, such as a nuclear fusion liquid metal blanket, where a liquid metal, such as lithium or a lithium-lead alloy, is used as the liquid metal coolant that may be pumped by the EMP.

[0054] Based on an EMP that includes gamma shielding materials and / or neutron absorbing materials therein, the EMP can reduce, minimize, or prevent expensive radiation testing, can enable many flexible reactor designs since the EMP can be located anywhere within the reactor vessel, and can enhance heat transfer between pump components and the liquid metal coolant to enable self-cooling of the EMP. Furthermore, an EMP with gamma shielding materials and / or neutron absorbing materials according to some example embodiments can be configured for easy and rapid implementation without requiring component program development or significant research efforts.

[0055] An EMP including gamma shielding materials and / or neutron absorbing materials according to any of the example embodiments may be configured to reduce, minimize, or prevent wear and / or damage (e.g., degradation and / or activation) of pump materials and / or components due to radiation (e.g., gamma rays and / or ambient neutrons received from the surrounding environment external to the EMP). Thus, the EMP may have an extended life while located within the reactor vessel; it may be located closer to the reactor core, thereby increasing reactor design flexibility and reducing reactor vessel system costs; expensive irradiation testing to qualify insulator life under the temperature, voltage, and radiation conditions present inside the reactor may be reduced, minimized, or eliminated; gamma and neutron exposure to EMP components (e.g., internal components) at elevated temperatures may be reduced, thereby improving EMP reliability; various EMP configurations, including self-cooled EMPs, may be implemented without constraints from design, size, or performance requirements; compatibility with other pump components and reactor structural materials in terms of thermophysical and neutronic properties may be maintained; and activation of pump components may be reduced, minimized, or prevented, allowing for faster maintenance and less complex pump decommissioning procedures.

[0056] FIG. 1 is a schematic diagram of a nuclear reactor facility including a liquid metal cooled nuclear reactor, according to some example embodiments.

[0057] Nuclear reactor facility 100 includes a liquid metal-cooled nuclear reactor (referred to herein simply as "reactor") 110, a primary coolant loop 119, an intermediate coolant loop 160, a power source 144 (e.g., a multi-phase power source), and an EMP control system 150. Primary coolant loop 119 includes EMP 120 (e.g., an ALIP) electrically connected to power source 144 via power cable 146 (e.g., a multi-phase power cable, also referred to herein as one or more power conductors, power lines, etc.) configured to provide electrical power (e.g., multi-phase power) to EMP 120.

[0058] The nuclear reactor 110 includes a reactor pressure vessel 111. The reactor pressure vessel 111 includes a reactor core 112 and a plurality of components within a volume defined at least in part by an outer wall 111S. The plurality of components includes a primary coolant loop 119, also referred to herein as a primary loop. The primary coolant loop 119 may be configured to remove heat generated in the reactor core 112 as a result of nuclear reactions therein. The primary coolant loop 119 shown in FIG. 1 is configured to circulate a liquid metal coolant 190 through at least a portion of the reactor core 112 to remove heat from the reactor core 112 generated in the reactor core 112 as a result of nuclear reactions therein. Such heat removal may also be referred to herein as core heat removal.

[0059] As shown, primary coolant loop 119 includes primary heat exchanger 114. Primary heat exchanger 114 is configured to transfer heat from liquid metal coolant 190 exiting reactor core 112 to another coolant. The other coolant circulates through intermediate coolant loop 160. In some exemplary embodiments, the other coolant may include a liquid metal coolant. The liquid metal coolants circulating through the primary and intermediate coolant loops may be a common liquid metal material or different liquid metal materials.

[0060] The primary coolant loop 119 includes a suction reservoir 116, sometimes referred to as a "cold" reservoir or pool, that is configured to receive the liquid metal coolant 190 exiting the primary heat exchanger 114 after the liquid metal coolant 190 transfers core-generated heat to the intermediate coolant loop 160.

[0061] The primary coolant loop 119 includes an EMP 120. The EMP 120 is configured to operate to circulate a liquid metal coolant 190 through the nuclear reactor 110, as shown in FIG. 1 . While FIG. 1 shows only one power source 144 and one EMP 120 within the nuclear reactor 110, and the following description of FIG. 1 may refer to “a” or “the” EMP 120 and “a” or “the” power source 144, it will be understood that multiple EMPs 120 may be included within the nuclear reactor 110, and at least some of the multiple EMPs 120 may be configured to operate in parallel or series with one another to circulate the liquid metal coolant through the nuclear reactor. Additionally, multiple power sources 144 may be included in the nuclear reactor installation 100, and each EMP 120 of the multiple EMPs 120 within the nuclear reactor 110 may be electrically connected to the same or different power source 144 as the other EMPs 120 within the nuclear reactor 110.

[0062] The EMP 120 is coupled at an inlet or inlet 122 to the suction reservoir 116 via a suction line 121, also referred to herein as a pump inlet manifold. As shown in at least FIG. 2B , the EMP 120 may be further coupled at the inlet or inlet 122 to the suction reservoir 116 via one or more stationary shield cylinders 204. The EMP 120 is coupled at an outlet orifice or outlet 123 to the core inlet plenum 118 via one or more return lines 124, also referred to as one or more pump discharge pipes. The EMP 120 is configured to drive at least some or all of the liquid metal coolant 109 into the core inlet plenum 118 and is further configured to generate at least some or all of a pressure head downstream of the EMP 120. The pressure head may provide a driving force for circulating the liquid metal coolant through the reactor core 112, as shown.

[0063] As further shown in at least FIG. 2B , the reactor may include a “hot” reservoir 202, also referred to herein as a hot pool, in which liquid metal coolant exiting the reactor core 112 may circulate between the reactor core 112 and the primary heat exchanger 114, the “hot” liquid metal coolant circulating from the hot reservoir 202 through the primary heat exchanger to the suction reservoir 116, and the liquid metal coolant exiting the primary heat exchanger 114 to the suction reservoir is “cold” liquid metal coolant that is cooler than the hot liquid metal coolant in the hot reservoir 202.

[0064] Power source 144 may be any power source or source configured to provide electrical power, including, for example, a polyphase power source (e.g., a three-phase AC power source). Power source 144 may also be an AC power source. For example, power source 144 may be an adjustable speed drive, also known as a variable speed drive, configured to receive 60 Hz AC ("alternating current") power (e.g., from plant mains 140 and / or generator 141), convert the received AC power to DC ("direct current"), and then convert power from DC to AC at a particular ("characteristic") current and frequency of the polyphase power supplied to EMP 120.

[0065] As further shown, the power source 144 is electrically coupled to one or more of the main power source 140 or the generators 141 of the nuclear reactor facility 100. In some exemplary embodiments, the nuclear reactor facility 100 includes one or more switchgear (not shown in FIG. 1 ) configured to selectively provide electrical power from one or more of the main power source 140 or the one or more generators 141 to the power source 144. The generators 141 may include one or more of an internal combustion engine, a fuel cell device, a battery, an uninterruptible power supply (UPS), some combination thereof, etc. The plant main power source 140 may include a power source configured to provide electrical power generated based on the process fluid circulating through the power generation loop 170.

[0066] In some exemplary embodiments, if EMP 120 includes multiple induction coils configured to be electrically connected to power source 144 (e.g., a polyphase power source) via power cable 146 (e.g., a polyphase power source), power cable 146 may be configured to provide power (e.g., polyphase power) to the induction coils of EMP 120. Power cable 146 may extend within EMP 120 and may be electrically coupled to the induction coils of EMP 120. Thus, the induction coils of EMP 120 may be electrically connected to power cable 146.

[0067] As shown in FIG. 1 , the power cable 146 may be disposed within a single power conductor 180 (e.g., an at least partially or completely enclosed cable, etc.) extending from the EMP 120 (e.g., also referred to herein as a “power conductor cable,” “conduit,” or “extension cable”) that extends from at least a pump casing (also referred to herein as the outer housing of the EMP 120) of the EMP 120 to at least the exterior of the reactor pressure vessel 111 through openings or “penetrations” 182 in the outer wall 111S of the reactor pressure vessel 111, such that the multiple induction coils of the EMP 120 can be electrically coupled to the power source 144 through openings 182 in the outer wall 111S of the reactor pressure vessel 111. As a result, electrical connection between the EMP within the reactor pressure vessel 111 and the power source 144 outside the reactor pressure vessel 111 may be achieved at an opening 182 (e.g., a penetration) through the reactor pressure vessel 111 sidewall.

[0068] Although FIG. 1 illustrates power conductor 180 extending through opening 182 and further to power source 144, it will be understood that power conductor 180 may terminate anywhere outside reactor pressure vessel 111 between opening 182 and power source 144, and power cable 146 may extend from the end of power conductor 180 and continue to extend from the end of power conductor 180 to power source 144.

[0069] The nuclear reactor facility 100 includes an intermediate coolant loop 160, also referred to herein as a secondary coolant loop, a secondary loop, etc. The intermediate coolant loop 160 includes a coolant flow circulating through a line 161 between the primary heat exchanger 114 and an intermediate heat exchanger 162. The intermediate coolant loop 160 may transfer core reject heat from a liquid metal coolant 190 circulating through the primary coolant loop 119 to a process fluid circulating through the power generation loop 170 via heat transfer at the intermediate heat exchanger 162. In some exemplary embodiments, the coolant circulating through the intermediate coolant loop includes a liquid metal coolant. The liquid metal coolant circulating through the intermediate coolant loop may be similar in composition to or different from the liquid metal coolant 190 circulating through the primary coolant loop 119.

[0070] The nuclear reactor facility 100 includes a power generation loop 170 configured to receive heat from the intermediate coolant loop 160 via a heat exchanger 162 and circulate a process fluid that performs work, including driving a turbine. The turbine may power an electrical generator. The process fluid may include one or more different phases of water. In some exemplary embodiments, the power generation loop 170 includes a steam generator apparatus in which the intermediate heat exchanger 162 is at least partially disposed, the heat exchanger 162 configured to transfer heat from the coolant circulating through the intermediate coolant loop 160 to water disposed within the steam generator to vaporize the water and generate steam. The generated steam may be used to perform work, such as driving a turbine connected to an electrical generator to generate electricity.

[0071] In some demonstrative embodiments, the nuclear reactor includes one or more control systems configured to monitor and / or control the operation of the EMP 120, including controlling the power supply (e.g., magnitude, frequency, etc.) to the induction coils in the EMP 120 to adjustably control the flow (e.g., flow rate, which may be mass flow rate and / or volumetric flow rate) of the liquid metal coolant 190 within the reactor 110, the performance of the reactor 110, and / or the operating efficiency of the reactor 110. As shown in FIG. 1 , the nuclear reactor 110 may include an EMP control system 150. The EMP control system 150 may be communicatively coupled 151 to the power source 144 via one or more communication lines, power lines, etc. In some exemplary embodiments, EMP control system 150 is connected via one or more communication lines, power transmission lines, etc. to one or more sensor devices (e.g., sensors which may be one or more flow meters, such as one or more Venturi flow meters, which may be configured to generate sensor data indicative of the pressure of liquid metal coolant 190 through suction line 121, return line 124, and / or EMP 120, one or more pressure sensors which may be configured to generate sensor data indicative of the pressure of liquid metal coolant 190 at one or more locations within suction line 121, return line 124, and / or EMP 120, etc.), and / or devices within reactor pressure vessel 111, including EMP 120, for example, although exemplary embodiments are not limited thereto.

[0072] In some exemplary embodiments, EMP control system 150 may be coupled to one or more sensors configured to generate sensor data associated with one or more sensor devices (e.g., one or more flow meters, such as one or more Venturi flow meters, that may be configured to generate sensor data indicative of the pressure of liquid metal coolant 190 passing through suction line 121, return line 124, and / or EMP 120, one or more pressure sensors that may be configured to generate sensor data indicative of the pressure of liquid metal coolant 190 at one or more locations within suction line 121, return line 124, and / or EMP 120, etc.), power source 144, EMP 120, etc.

[0073] EMP control system 150 can monitor the operation of EMP 120 based on monitoring information associated with power source 144, one or more sensor devices (e.g., one or more flow meters, such as one or more Venturi flow meters, that can be configured to generate sensor data indicative of the flow rate of liquid metal coolant 190 through suction line 121, return line 124, and / or EMP 120, one or more pressure sensors that can be configured to generate sensor data indicative of the pressure of liquid metal coolant 190 at one or more locations within suction line 121, return line 124, and / or EMP 120), EMP 120, etc. For example, EMP control system 150 can receive sensor data generated by one or more sensor devices, where the sensor data can include information indicative of the flow of power from a given power source to a given multi-stage EMP 120. In another example, EMP control system 150 can receive sensor data generated by one or more sensor devices, where the sensor data can include information indicative of the strength of the magnetic field generated by the induction coil of a given EMP 120.

[0074] EMP control system 150 may be configured to control the operation of EMP 120, such as controlling the flow rate of liquid metal coolant through EMP 120, based on independently controlling and / or regulating the supply of power by power sources 144. For example, if EMP 120 includes multiple induction coils electrically connected to power sources 144 via power cables 146, EMP control system 150 may independently control and / or regulate the power (e.g., poly-phase power) supplied by power sources 144 to control EMP 120. Such control of power sources 144 may include causing power sources 144 to initiate the supply of poly-phase power to the induction coils of EMP 120 via power cables 146, causing power sources 144 to adjust the frequency and / or current of the power supplied by power sources 144, and / or causing power sources 144 to inhibit the supply of power to the electrically connected induction coils of EMP 120 via power cables 146. Such control may be implemented based on the EMP control system 150 executing code stored in memory to generate and transmit control signals to the power source 144.

[0075] The EMP control system 150, in some exemplary embodiments, includes one or more computer systems. The computer system may include one or more instances of circuitry. The one or more instances of circuitry may include one or more processor devices (“processors”) coupled to one or more instances of memory (e.g., an article, a part, etc.). The one or more processors may include one or more central processing units (CPUs). The one or more processors may be configured to implement the EMP control system. For example, one or more instances of memory (e.g., one or more memories) may include a non-transitory computer-readable medium (e.g., a solid-stage drive) that stores a program of instructions, and the one or more processors may include processing circuitry configured to execute the program of instructions stored on the non-transitory computer-readable medium to perform one or more operations of any of the methods according to any of the exemplary embodiments.

[0076] In some exemplary embodiments, EMP 120 provides improved flexibility and control over the liquid metal coolant flow rate in primary coolant loop 119 because EMP control system 150 can apply more flexible control over the flow rate based on controlling EMP 120 based on controlling the multi-phase power supplied by power source 144 to the separate induction coils of EMP 120. Different configurations (e.g., parameters) of the multi-phase power supplied to EMP 120 can increase the range of operating conditions of EMP 120 that can be achieved by EMP control system 150, including an increased range of separate, isolated flow rates (e.g., increased amounts) of liquid metal coolant 190 that can be induced by EMP 120. As a result, the operational performance and / or efficiency of primary coolant loop 119, and thus reactor 110 and nuclear reactor installation 100 as a whole, can be improved based on the improved control over the flow rate of liquid metal coolant 190 enabled by EMP 120.

[0077] In some exemplary embodiments, and as described herein, EMP 120 may be self-cooling and configured to reject heat therefrom without including an additional and / or separate coolant circulating therethrough. For example, EMP 120 may be configured to conduct heat generated by its internal components (e.g., stator, induction coil, etc.) to a flow conduit (e.g., an annular fluid passage) through which liquid metal coolant 190 flows within EMP 120, with liquid metal coolant 190 absorbing the conducted heat and removing the heat from EMP 120 as it exits EMP 120 via outlet 123.

[0078] In some exemplary embodiments, intermediate coolant loop 160 includes one or more EMPs 120, which are shown included in primary coolant loop 119. The EMPs 120 included in intermediate coolant loop 160 may be configured to operate similarly to the EMPs 120 included in primary coolant loop 119. The set of one or more EMPs 120 included in the intermediate loop may be located inside or outside of reactor pressure vessel 111.

[0079] As referred to herein, the liquid metal coolant may include one or more of a variety of liquid metal materials, including one or more of sodium, mercury, lead, bismuth, or tin. The one or more liquid metal materials may be electrically conductive metallic materials such that the EMP 120 is configured to circulate the liquid metal coolant.

[0080] 2A is a perspective view of a liquid metal-cooled nuclear reactor according to some example embodiments. FIG. 2B is a plan view of a liquid metal-cooled nuclear reactor according to some example embodiments. The reactor 110 shown in FIGS. 2A-2B may be included in any of the reactor embodiments included herein, including the reactor 110 shown in FIG.

[0081] 2A-2B, reactor 110 may include a reactor pressure vessel 111 and may further include a set of multiple EMPs 120 within reactor pressure vessel 111, although it will be understood that in some exemplary embodiments, only a single EMP 120 may be included within reactor pressure vessel 111. As shown in FIGS. 2A-2B, when reactor 110 includes multiple EMPs 120, EMPs 120 may be coupled in parallel to separate parallel return lines 124 and configured to operate in parallel within primary coolant loop 119 such that each EMP 120 may direct parallel flow of a separate portion of liquid metal coolant 190 through primary coolant loop 119.

[0082] Each of the EMPs 120 shown in Figures 2A-2B may be structurally identical or different from one another. For example, the EMPs 120 may have the same configuration of induction coils, component structures, and / or component-specific properties. In some exemplary embodiments, the EMPs 120 may have different configurations of induction coils, component structures, and / or component-specific properties.

[0083] FIG. 3A is a perspective view of an EM pump (EMP) according to some exemplary embodiments. FIG. 3B is a perspective cross-sectional view along cross-section line IIIB-IIIB′ shown in FIG. 3A according to some exemplary embodiments. FIG. 4A is a cross-sectional view of the EMP of FIG. 3A along cross-section line IVA-IVA′ shown in FIG. 3A according to some exemplary embodiments. FIG. 4B is a cross-sectional view of the EMP of FIG. 4A along cross-section line IVB-IVB′ shown in FIG. 3A according to some exemplary embodiments. FIG. 4C is a cross-sectional view of the EMP of FIG. 4A along cross-section line IVC-IVC′ shown in FIG. 3A according to some exemplary embodiments. FIG. 4D is a cross-sectional view of the EMP of FIG. 3A along cross-section line IVA-IVA′ shown in FIG. 3A according to some exemplary embodiments.

[0084] The EMP 120 shown in Figures 3A-4C and the EMP 120 shown in Figure 4D may be included in any of the EMPs 120 included herein, including one or more EMPs 120 illustrated in Figure 1 and / or Figures 2A-2B. While the EMP 120 shown in Figures 3A-4D may be an ALIP, exemplary embodiments of an EMP are not limited to an ALIP and may include any type of EMP.

[0085] Although the EMP 120 shown in FIGS. 3A-4C is illustrated as a dual-stator EMP, example embodiments are not so limited, and the description herein of any EMP 120 and any portion thereof may apply to any EMP 120 having more or less than two stators, such as the single-stator EMP shown in FIG. 4D.

[0086] 3A-4D, the EMP 120 may include a longitudinally extending pump casing 302 (also referred to as an outer housing, outer casing, casing structure, etc.) having a longitudinal central axis. As shown in FIGS. 3A-3B, the pump casing 302 may partially or completely define (e.g., at least partially define) an interior space (e.g., interior 380) of the EMP 120. As further shown, the longitudinal central axis of the pump casing 302 may be parallel to and / or coaxial with (e.g., may be identical to and / or at least partially define) the longitudinal axis 306 of the EMP 120.

[0087] It will be understood that while pump casing 302 may include one or more structures (e.g., one or more pieces of material) and / or be open at opposing longitudinal ends of EMP 120, in some exemplary embodiments pump casing 302 may include one or more structures that may partially or completely enclose opposing longitudinal ends of the interior space, except for openings in pump casing 302 that define inlet 122 and outlet 123 of EMP 120. For example, as shown in at least FIGS. 3A-3B, 4A, and 4D, pump casing 302 may be a hollow cylindrical structure and may include outer sidewall structure 302-1 that may at least partially define interior 380 of EMP 120 as a hollow cylindrical volume. The pump casing 302 may further include respective ring-shaped end structures 302-2 that at least partially structurally surround the inlet longitudinal end of the EMP 120 and / or the outlet longitudinal end of the EMP 120, except for one or more openings to the inlet longitudinal end of the annular fluid passage 312 and / or the outlet longitudinal end of the annular fluid passage 312, wherein the one or more openings (e.g., one or more arc-shaped and / or annular openings) at least partially define the inlet 122 to the annular fluid passage 312 and / or the outlet 123 of the annular fluid passage 312, and thus the inlet 122 and / or the outlet 123 to and / or from the EMP 120. While end structure 302-2 is shown as being a separate structure (e.g., a separate piece of material) from outer sidewall structure 302-1, exemplary embodiments are not limited thereto, and in some exemplary embodiments, end structure 302-2 and outer sidewall structure 302-1 may each comprise separate portions of a single, integral piece of material. In some exemplary embodiments, end structure 302-2 may be omitted from pump casing 302. As shown in at least FIGS. 3A-3B , pump casing 302 (e.g., at least outer sidewall structure 302-1) may have a longitudinally extending longitudinal axis that at least partially defines (e.g., is coaxial with, is the same as, etc.) longitudinal axis 306 of EMP 120.

[0088] 3A-3B, 4A, and 4D, the pump casing 302 may include an inner sidewall structure 302-3 that, together with the outer sidewall structure 302-3, at least partially defines an outer annular space 304 extending coaxially with the longitudinal axis 306. The outer annular space 304 may include empty space and / or may include one or more materials, such as one or more thermal insulating materials, one or more electrically insulating materials, etc. In some exemplary embodiments, the inner sidewall structure 302-3 may be omitted. In some exemplary embodiments, the pump casing 302 may be configured with the outer sidewall structure 302-1 alone or in combination with one or more end structures 302-2. In some exemplary embodiments, the inner sidewall structure 302-3, the end structure 302-2, and the outer sidewall structure 302-1 may include separate pieces of material and / or each may include separate portions of a single, integral piece of material.

[0089] The pump casing 302, the inlet structure 302-1, and / or the outlet structure 302-2 may include one or more metallic materials, such as, for example, stainless steel (eg, 304 stainless steel), carbon steel, and the like.

[0090] 3A-3B, the EMP 120 may include concentric flow ducts 310 extending coaxially with the longitudinal axis 306 and collectively defining an annular fluid passage 312 extending coaxially with the longitudinal axis 306 along the length of the EMP 120 (e.g., the entire length as shown in FIG. 3A). As shown, the concentric flow ducts 310 may include an inner flow duct 310-1 and an outer flow duct 310-2, each of which may be a cylindrical structure (e.g., a cylindrical tube, a hollow cylindrical structure, etc.), although exemplary embodiments are not limited thereto. As shown, the outer surface 310-1 of the inner flow duct 310-1 and the inner surface 310-2 of the outer flow duct 310-2 collectively define the annular fluid passage 312 as the annular space, or "annulus," between these surfaces. As shown in Figures 3A-3B, each of the concentric flow ducts 310 (also referred to herein as concentric annular walls) may be a cylindrical tube, although example embodiments are not limited thereto.

[0091] 3A-3B, the EMP 120 may include multiple induction coils 320 (which may include, for example, coils of wound copper wire) within the interior space of the EMP 120. As shown, each induction coil 320 surrounds the longitudinal axis 306 and has a central axis that is coaxial with the longitudinal axis 306. As shown in at least FIGS. 3B, 4A, and 4D, the induction coils 320 are spaced apart from one another (e.g., isolated from direct contact with one another) in a longitudinal direction extending coaxially with the longitudinal axis 306. In some exemplary embodiments, the induction coils 320 may be referred to as "solenoids" of the stator of the EMP 120. The induction coils 320 may each include one or more conductive materials (e.g., one or more windings of a conductive material), including copper, silver, etc.

[0092] As further shown in FIGS. 3A-3B, 4A, 4B, and 4D, the EMP 120 may include a stator 322 including an outer stator 322-1 located radially distal from the longitudinal axis 306 relative to the outer flow duct 310-2 and an inner stator 322-2 located radially proximal from the longitudinal axis 306 relative to the inner flow duct 310-1. The stator 322 may be made of one or more magnetic materials, such as magnetic iron. The outer stator 322-1 and the inner stator 322-2 may be made of the same material composition or different material compositions. For example, the outer stator 322-1 and the inner stator 322-2 may each be made of iron (e.g., magnetic iron), although example embodiments are not limited thereto. For example, at least one of the outer stator 322-1 or the inner stator 322-2 may be made at least partially of stainless steel in some example embodiments.

[0093] Although each of the outer stator 322-1 and the inner stator 322-2 is shown as a single structure, at least one of the outer stator 322-1 or the inner stator 322-2 may be comprised of multiple stator structures (e.g., block structures), for example, eight block structures. The block structures may be linear beam structures or bar-like structures (e.g., linear beam structures or bar-like block structures) that each extend coaxially with respect to the longitudinal axis 306 along the length of the EMP 120 and may be at least partially spaced apart azimuthally about the longitudinal axis 306. In some exemplary embodiments, the outer stator 322-1 may be comprised of one or more arc-shaped structures or a single cylindrical structure that extends to surround part or all of the circumference of the outer surface 310-2os of the outer flow duct 310-2. However, an outer stator 322-1 including multiple, spaced-apart block structures may provide weight savings in the EMP 120 relative to an outer stator 322-1 that is a single-piece cylindrical structure.

[0094] As shown in Figures 3A-3B, 4A-4B, and 4D, in some exemplary embodiments, inner stator 322-2 may be comprised of a unique cylindrical structure that extends around longitudinal axis 306 and further extends longitudinally coaxially with longitudinal axis 306.

[0095] 3A-4D, the EMP 120 may include multiple induction coils 320, which may include at least one of an inner induction coil 320-2 located within a central region 382 of the EMP 120 interior 380 defined at least in part by the inner surface 310-1is of the inner flow duct 310-1, or an outer induction coil 320-1 located within an annular region 384 of the EMP 120 interior 380 defined at least in part between the outer surface 310-2os of the outer flow duct 310-2 and the inner surface 302is of the pump casing 302.

[0096] 3B and 4A and 4D, the outer stator 322-1 may include longitudinally spaced apart tooth structures 324-1 configured to receive and surround a separate induction coil 320 (e.g., outer induction coil 320-1) therebetween, at least in a longitudinal direction coaxial with the longitudinal axis 306 and a radial direction distal to the longitudinal axis 306. In an exemplary embodiment in which the EMP 120 is a dual-stator EMP having an inner induction coil 320-2, as shown in at least FIGS. 3B and 4D, the inner stator 322-1 may include longitudinally spaced apart tooth structures 324-2 configured to receive and surround a separate inner induction coil 320-2 therebetween, at least in a longitudinal direction coaxial with the longitudinal axis 306 and a radial direction distal to the longitudinal axis 306. In exemplary embodiments in which EMP 120 is a single-stator EMP 120, as shown in at least FIG. 4D, inner stator 322-2 may be a hollow cylindrical structure.

[0097] As shown, each tooth structure 324-1 or 324-2, together with the adjacent flow passage 310, may define an annular space 332 in which a separate induction coil 320 may be disposed. The remaining portion of the annular space 332 not occupied by the induction coil 320 may include an electrically insulating material 336 surrounding the induction coil 320. Such electrically insulating material 336 may partially or completely fill the remaining portion of the annular space 332 not occupied by the induction coil 320. Such electrically insulating material 336 may include any known electrically insulating material, including, for example, polyvinyl chloride (PVC). The electrically insulating material 336 may be thermally conductive and may be configured to conduct heat from the induction coil 320 and / or the stator 322 through the flow duct 310 to the annular fluid passage 312 to facilitate self-cooling of the EMP 120 based on rejection of internally generated heat to the liquid metal coolant 190 flowing through the annular fluid passage 312. For example, in some exemplary embodiments, electrically insulating material 336 may include any known electrically insulating, thermally conductive material, including, for example, mica (Phyllosilicate). Electrically insulating material 336 may conduct heat generated in either induction coil 320 and / or stator 322 to flow duct 310, allowing the heat to be conducted through flow duct 310 to annular fluid passage 312 and absorbed by liquid metal coolant 190 flowing therethrough, thereby enabling self-cooling of EMP 120 internal components via heat rejection to liquid metal coolant 190 flowing therethrough and exiting EMP 120 via outlet 123.

[0098] 3A-3B, 4A, and 4D, in some exemplary embodiments, EMP 120 may include a central core 326 (which may be constructed from a material such as stainless steel, magnetic iron, or the like) that may be a hollow cylindrical structure having one or more inner cylindrical sidewalls that define a central space 328 (e.g., a central void) that extends coaxially with longitudinal axis 306 (e.g., located at the radial center of EMP 120). In some exemplary embodiments, central core 326 may be omitted such that inner stator 322-2 includes one or more inner cylindrical sidewalls that define central space 328 (e.g., a central void), as described herein. Central space 328 may be configured to accommodate (e.g., house) cabling for EMP 120, to direct a heat exchange fluid (e.g., a coolant gas such as helium) therethrough, and the like to provide cooling to EMP 120. In some exemplary embodiments, the central core 326 or inner stator 322-2 may be a solid cylindrical structure that occupies some or all of the space defined by the inner diameter of the inner flow duct 310-1, such that the central space 328 may be omitted from the EMP 120.

[0099] In some exemplary embodiments, an outer annular space 304 (e.g., an outer gap) defined at least in part by the outer sidewall structure 302-1 can extend around (e.g., radially distal from) the outer stator 322-1 and the induction coil 320, between the inner surface 302 of the pump casing and the outer surface of the induction coil 320 and / or the outer stator 322-1. The outer annular space 304 can be empty space and / or can be at least partially filled with a material (e.g., nitrogen gas, insulating material, circuitry, etc.).

[0100] 3A-3B, inner flow duct 310-1, inner stator 322-2, central core 326, and / or any structure located radially inward from inner flow duct 310-1 within EMP 120 may support outer flow duct 310-2, outer stator 322-1, induction coil 320, pump casing 302, and / or any structure located radially outward from outer flow duct 310-2 within EMP 120 by one or more support ribs ("stilts") extending radially outward between concentric flow ducts 310 within annular fluid passage 312. The inner flow duct 310-1 and the outer flow duct 310-2 are structurally coupled to one another via a support rib (also referred to as a support rib) that structurally couples the central / inner portion of the EMP 120 to the outer portion of the EMP 120, thus structurally stabilizing and supporting the central / inner portion (e.g., inner flow duct 310-1, inner stator 322-2, inner induction coil 320-2, etc.) relative to the outer portion (e.g., outer flow duct 310-2, outer stator 322-1, outer induction coil 320-1, pump casing 302, etc.). In some exemplary embodiments, the support rib may further extend through the outer annular space 304 between the outer stator 322-1 and the pump casing 302 to structurally stabilize and support at least the outer stator 322-1 relative to the pump casing 302. In some exemplary embodiments, the support rib may be omitted from the EMP 120. The pump casing 302 may include an inlet end structure 302-2 and an outlet end structure 302-2 coupled to an outer sidewall structure 302-1 of the pump casing 302 having a longitudinal axis 306, the end structure 302-2 being an outer portion of the EMP 120 (e.g., the outer flow duct 310-2, the outer stator 322-1, and / or the outer induction coil 320-1) and a central / inner portion of the EMP 120 (e.g., the inner flow duct 310-1, the inner stator 322-2, the inner induction coil 320-2, and / or the central core 326), and thus the inlet end structure 302-2 and the outlet end structure 302-2 may structurally couple, stabilize, and support the outer and central / inner portions of the EMP 120 relative to each other.

[0101] 3A-4D , the EMP 120 may be configured to pump (e.g., induce flow of) the liquid metal coolant 190 through the annular fluid passage 312 based on applying an electromagnetic force to the liquid metal coolant 109 flowing through the length of the EMP 120 (e.g., longitudinally extending coaxially relative to the longitudinal axis 306). This may be performed based on applying (e.g., supplying) electrical power (e.g., polyphase electrical power) to the induction coil 320 at a particular frequency and phase angle. For example, the polyphase electrical power described herein may include AC electrical power, e.g., three-phase AC electrical power, which may be applied at a particular AC frequency and phase angle to the induction coil 320 surrounding the annular fluid passage 312.

[0102] For example, referring to FIG. 4D , the induction coil 320 may include multiple separate sets or “slots” 330-1 through 330-3 of induction coils 320, each of which may be applied with a fixed phase of polyphase power from a particular, electrically connected polyphase power source, and a given set (e.g., 330-1, 330-2, or 330-3) may be 60 degrees or 120 degrees from the phase of the previous longitudinally adjacent induction coil 320 (in a direction opposite to the longitudinal direction coaxial with the longitudinal axis 306) to allow the sequence to complete a 360-degree AC cycle. The collection of induction coils 320 that complete this 360-degree AC cycle is referred to as a pole (τ) or “slot.” The length of the pole is determined by the pole pitch (τ p ) is called.

[0103] The supply of multi-phase power to the induction coils 320 may be controlled, for example, based on controlling the frequency, power amplitude (e.g., current and / or voltage), and / or phase angle of the supplied multi-phase power to induce a particular pressure rise in the liquid metal coolant 190 within the annular fluid passage 312 along the length (e.g., longitudinal direction coaxial with the longitudinal axis 306) of the EMP 120. With the electrical phase of each induction coil 320 fixed based on its connection to a separate wire of a particular power cable 146 and the internal components stationary within the pump casing 302, the pressure rise may be controlled based on controlling and / or adjusting the frequency, power amplitude (e.g., current and / or voltage), and / or phase angle of the multi-phase power supplied to the induction coils 320 from an electrically connected multi-phase power source (e.g., power source 144).

[0104] For a given volumetric flow rate, the applied current, voltage, and / or frequency of the polyphase power (e.g., three-phase AC power) supplied to a given set of induction coils 320 can be adjusted to provide a desired pressure rise in the liquid metal coolant 190 within the EMP 120. This is because changes in the current and frequency of the power supplied by a polyphase power source (e.g., power source 144) are applied to all induction coils 320 electrically connected to that same polyphase power source. Thus, the flow rate operating range and sensitivity of the EMP 120 can be based on the polyphase power source to which the induction coils 320 are electrically connected via the power cables 146.

[0105] With further reference to FIG. 4D , while the induction coil is shown as including three “slots” 330-1 through 330-3, it will be understood that the number of slots associated with a given phase may be a multiple of “N” slots 330-1 through 330-N in the induction coil 320, and that there may be more or fewer repeating “slots” in the EMP 120, where “N” is any positive integer.

[0106] 4D, the induction coil 320 may be connected via a polyphase power cable 146 (e.g., a three-phase conductor supplying phases A, B, and C of three-phase AC power from a polyphase power source 144) and thus may be controlled based on independently controlling the power supplied by the polyphase power source 144. Referring to FIGS. 3A-4A, in a dual-stator EMP 120, the inner induction coil 322-2 and the outer induction coil 322-1 at a given longitudinal position along the longitudinal axis 306 may be coupled to the same phase or separate phases of the polyphase power supplied by the polyphase power source.

[0107] 3A-4D , multi-phase power (e.g., three-phase AC power) may be applied to the induction coils 320 of the EMP 120, with the phase and current direction of each induction coil 320 being fixed or predetermined, such that the application of the multi-phase power to the induction coils 320 causes the induction coils 320 to generate traveling electromagnetic (EM) waves that induce a continuous flow of liquid metal coolant 190 located within the annular fluid passage 312 in a longitudinal direction coaxial with the longitudinal axis 306, from the inlet 122 to the outlet 123. The multi-phase power applied to one or more sets 330-1-330-3 of the induction coils 320 may have a particular frequency and power amplitude (e.g., current and / or voltage), which may be set (e.g., controlled and / or regulated) by the EMP control system 150 via controlling the power source 144 electrically connected to the induction coils 320. Thus, the frequency and / or power amplitude (e.g., voltage and / or current) of the multi-phase power supplied by the power source 144 may be controlled and / or adjusted (e.g., initiated, adjusted, and / or throttled). Such control and / or adjustment of the frequency and / or power amplitude of the multi-phase power applied to one or more sets of induction coils 320 of the EMP 120 varies the performance of the multi-stage ALIP in pumping (e.g., inducing flow of) the liquid metal coolant 190 therethrough.

[0108] 4A-4D , in some exemplary embodiments, at least one of the inner flow duct 310-1 or the outer flow duct 310-2 may include a gamma shielding material. The gamma shielding material is configured to shield an interior 380 of the EMP 120 that is defined at least in part by the pump casing 302 and is outside the annular fluid passage 312 (e.g., a central interior space 382 defined at least in part by the inner surface 310-1 of the inner flow duct 310-1 and / or an annular interior space 384 defined at least in part by the outer surface 310-2 of the outer flow duct 310-2 and the inner surface 302 of the pump casing 302) from gamma rays 460 (also referred to herein simply as gamma) emitted from the liquid metal coolant 190 flowing through the annular fluid passage 312. For example, the liquid metal coolant 190 drawn into the annular fluid passage 312 via the inlet 122 of the EMP 120 may be at a relatively high temperature, e.g., an inlet temperature of approximately 350° C., and may be highly energized, e.g., a liquid sodium coolant including Na-24. Because such liquid metal coolant 190 is highly energized and relatively hot, it may emit gamma rays 460 from the liquid metal coolant 190. Such gamma rays 460 may wear and / or damage (e.g., degrade and / or activate) internal components of the EMP 120, including the stator 322, the induction coil 320, the conductive circuitry, and any of the insulators, such as the electrically insulating material 336. Gamma shielding material within at least one of the flow ducts, the inner flow duct 310-1 or the outer flow duct 310-2, can block such gamma rays 460 within the annular fluid passage 312 from entering the interior 380 of the EMP 120 from the annular fluid passage 312 (e.g., a central interior space 382 defined at least in part by the inner surface 310-1is of the inner flow duct 310-1, and / or annular interior space 384 defined at least in part by the outer surface 310-2os of the outer flow duct 310-2 and the inner surface 302is of the pump casing 302).

[0109] As described herein, "blocking" gamma rays by a gamma shielding material (also referred to herein as "attenuating" and / or "shielding" gamma rays) may include reducing, minimizing, or preventing the transmission of incident gamma rays through the gamma shielding material such that they exit the gamma shielding material (e.g., pass completely through the gamma shielding material) and then enter (e.g., contact) another material, element, space, etc. after exiting the gamma shielding material. As described herein, gamma shielding materials can "block" (e.g., "attenuate") gamma rays (also referred to herein as gamma radiation) based on a variety of mechanisms. For example, gamma shielding materials can "shield" (e.g., "attenuate") gamma rays (e.g., incident gamma rays incident on the gamma shielding material) based at least in part on photoelectric absorption of the gamma rays by the gamma shielding material, which involves complete transfer of energy from the incident gamma ray photons to atomic electrons of the gamma shielding material. In another example, a gamma shielding material can "block" (e.g., "attenuate") gamma rays based at least in part on scattering (e.g., Compton scattering) of the gamma rays (e.g., incident gamma rays incident on the gamma shielding material). Scattering of gamma rays (e.g., Compton scattering) by a gamma shielding material involves transferring some of the energy of the incident gamma ray photon to atomic electrons of the gamma shielding material, causing the gamma ray photon to undergo further scattering or absorption upon interaction with the shielding material and / or emerge from the shielding material with reduced energy. In another example, a gamma shielding material can "shield" (e.g., "attenuate") gamma rays (e.g., incident gamma rays incident on the gamma shielding material) based at least in part on pair production involving the interaction of a relatively high-energy (e.g., at least 1022 keV) incident gamma ray photon with an atomic nucleus in the gamma shielding material, resulting in the production of a beta particle and a positron, which then undergoes an annihilation reaction with an electron to produce two lower-energy (e.g., 511 keV) gamma rays.

[0110] In exemplary embodiments in which at least one of inner flow duct 310-1 or outer flow duct 310-2 includes a gamma shielding material, the gamma shielding material can reduce, minimize, or prevent such gamma rays 460 from passing through the at least one flow duct to reach internal components of EMP 120 and cause wear and / or damage to such components. As described herein, the gamma shielding material in any exemplary embodiment (e.g., at least one of gamma shielding materials 414, 424 as shown in FIG. 4B ) can include one or more of lead, iron and steel alloys, tin, bismuth, tungsten and its alloys, water, or borated paraffin or polyethylene. In some exemplary embodiments, at least one flow duct can include a gamma shielding material as a filler material within an annular duct space defined between concentric cylindrical duct walls. The concentric cylindrical duct walls provide structural support for the at least one flow duct, and the gamma shielding material provided as a filler (e.g., a filler) therebetween may or may not provide structural integrity for the at least one flow duct. In some exemplary embodiments, the at least one flow duct may comprise gamma shielding material in a structure having a surface that at least partially defines the annular fluid passage 312, such that at least a portion of the gamma shielding material is directly exposed to the annular fluid passage 312. In other words, if the at least one flow duct 310 includes a material that at least partially defines an inner surface or an outer surface (e.g., inner surface 310-2is or 310-1os, respectively) of the annular fluid passage 312, then that material may include gamma shielding material.

[0111] In some exemplary embodiments, at least one flow duct may be constructed from a monolithic material comprising a gamma shielding material alone or in combination with one or more additional materials (e.g., a mixture of at least one of the aforementioned gamma shielding materials with stainless steel).

[0112] In some exemplary embodiments, at least one of the flow ducts, inner flow duct 310-1 or outer flow duct 310-2, can include concentric cylindrical duct walls defining a duct annulus therebetween, and the gamma shielding material can be located within the duct annulus, for example, as a filler material within the duct annulus. 4B , the inner flow duct 310-1 can include concentric cylindrical duct walls 410-1 and 410-2 that collectively define an inner duct annulus 412 between their respective outer and inner surfaces 410-1os, 410-2is, with the inner surface 410-1is of the inner cylindrical duct wall 410-1 defining the inner surface of the inner flow duct 310-1 and the outer surface 410-2os of the outer cylindrical duct wall 410-2 defining the inner flow duct outer surface 310-1os that at least partially defines the annular fluid passage 312 of the EMP 120. As shown, the gamma shielding material 414 can be disposed in (e.g., partially or completely fill) the inner duct annulus 412, for example, as a filler that partially or completely fills the inner duct annulus 412. As shown, the gamma shielding material 414 may be one or more pieces of material and may have an outer surface 414os in contact with the inner surface 410-2is of the outer cylindrical duct wall 410-2, although example embodiments are not limited thereto. As shown, the gamma shielding material 414 may be one or more pieces of material and may have an inner surface 414is in contact with the outer surface 410-1os of the inner cylindrical duct wall 410-1, although example embodiments are not limited thereto. The gamma shielding material 414 may be provided as a filler material within the inner duct annulus 412, although example embodiments are not limited thereto. In some example embodiments, one or more of the cylindrical duct walls 410-1 or 410-2 may be omitted from the inner flow duct 310-1, and in some example embodiments, the gamma shielding material 414 may contribute to the structural support and / or integrity of at least the inner flow duct 310-1. In some exemplary embodiments, the inner flow duct 310-1 may be constructed from a single material that includes a gamma shielding material alone or as a mixture of a gamma shielding material and one or more additional materials (e.g., stainless steel).

[0113] 4B , the outer flow duct 310-2 can include concentric cylindrical duct walls 420-1 and 420-2 that collectively define an outer duct annulus 422 between their respective outer and inner surfaces 420-1os and 420-2is, with the inner surface 420-1is of the inner cylindrical duct wall 420-1 defining the inner surface of the outer flow duct 310-2 that at least partially defines the annular fluid passage 312 of the EMP 120, and the outer surface 420-2os of the outer cylindrical duct wall 420-2 defining the outer flow duct outer surface 310-2os. As shown, the gamma shielding material 424 can be disposed in (e.g., partially or entirely fills) the outer duct annulus 422 and provided as a filler that partially or entirely fills the outer duct annulus 422. As shown, the gamma shielding material 424 may be one or more pieces of material and may have an outer surface 424os that contacts the inner surface 420-2is of the outer cylindrical duct wall 420-2, although example embodiments are not limited thereto. The gamma shielding material 424 may be provided as a filler material within the outer duct annulus 422, although example embodiments are not limited thereto. As shown, the gamma shielding material 424 may be one or more pieces of material and may have an inner surface 424is that contacts the outer surface 420-1os of the inner cylindrical duct wall 420-1, although example embodiments are not limited thereto. In some example embodiments, one or more of the cylindrical duct walls 420-1 or 420-2 may be omitted from the outer flow duct 310-2, and in some example embodiments, the gamma shielding material 424 may contribute to the structural support and / or integrity of at least the outer flow duct 310-2. In some exemplary embodiments, the outer flow duct 310-2 may be constructed from a single material that includes a gamma shielding material alone or as a mixture of a gamma shielding material and one or more additional materials (e.g., stainless steel).

[0114] In some exemplary embodiments, at least one of inner flow duct 310-1 or outer flow duct 310-2 may include a material that at least partially defines inner surface 310-1os or outer surface 310-2is of annular fluid passage 312, where the material includes a gamma shielding material. For example, in some exemplary embodiments, outer cylindrical structure 410-2 and gamma shielding material 414 may be replaced by a single cylindrical structure having an outer surface that at least partially defines outer surface 310-1os of inner flow duct 310-1 and including a gamma shielding material, alone or in combination with another material, where inner cylindrical structure 410-1 may or may not be present in inner flow duct 310-1. As another example, in some exemplary embodiments, the inner cylindrical structure 420-1 and the gamma shielding material 424 can be replaced with a single cylindrical structure having an inner surface that at least partially defines the inner surface 310-2 of the outer flow duct 310-2 and that includes a gamma shielding material, alone or in combination with another material, and the outer cylindrical structure 420-2 can be present or absent from the outer flow duct 310-2. As shown in at least FIG. 4B , each of the inner flow duct 310-1 and the outer flow duct 310-2 can include one or more gamma shielding materials. In some exemplary embodiments, the inner flow duct 310-1 and the outer flow duct 310-2 can include the same or different gamma shielding materials. In some exemplary embodiments, one of the inner flow duct 310-1 or the outer flow duct 310-2 does not include a gamma shielding material.

[0115] Based on EMP 120 including gamma shielding material (e.g., 414 and / or 424) in at least one flow duct of inner flow duct 310-1 or outer flow duct 310-2, EMP 120 can be configured to reduce, minimize, or prevent wear and / or damage to EMP 120 (e.g., its internal components, including stator 322, induction coil 320, electrical insulation material 336, etc.). As a result, EMP 120 can be configured to reduce, minimize, or prevent expensive radiation testing, enable many flexible reactor designs because the EMP can be located anywhere within the reactor vessel, and enhance heat transfer between pump components and liquid metal coolant 190 (e.g., via thermally conductive electrical insulation material 336) to enable self-cooling of the EMP. Furthermore, EMPs with gamma shielding material according to some example embodiments can be configured to be easily and quickly implemented without requiring component program development or significant research efforts. Furthermore, based on including gamma shielding material 414 and / or 424 in at least one flow duct within EMP 120, EMP 120 may be configured to reduce, minimize, or prevent degradation (e.g., wear) and / or damage to pump materials due to radiation at high temperatures inside reactor pressure vessel 111.

[0116] While at least the exemplary embodiment shown in FIG. 4B illustrates the inclusion of gamma shielding material in at least one flow duct 310 (also referred to herein as at least one duct), either inner flow duct 310-1 or outer flow duct 310-2, exemplary embodiments are not limited thereto, and in some exemplary embodiments, the gamma shielding material may be included in any of the components of EMP 120 (e.g., included in pump casing 302 as a filler material and / or as part of an alloy material that at least partially constitutes pump casing 302).

[0117] 3A-4D , in some exemplary embodiments, pump casing 302 may include a neutron absorbing material. The neutron absorbing material may be configured to absorb neutrons (e.g., ambient neutrons 470) entering pump casing 302 from outside EMP 120 (e.g., ambient environment 450, which is outside EMP 120), thereby reducing, minimizing, or preventing wear and / or damage to EMP 120 and / or any of its internal components due to exposure to ambient neutrons 470 from ambient environment 450, which is the relatively high temperature and high radiation environment within reactor pressure vessel 111. The neutron absorber material, in any exemplary embodiment, may include one or more of gadolinium, cadmium, boron, boron carbide, gadolinium oxide, hafnium lithium, tantalum, europium, gadolinium stainless steel, hafnium, silver, xenon, or indium. The neutron absorbing material may be provided as a filler material within an annulus at least partially defined between the concentric cylindrical casing walls (e.g., partially or entirely filled), although example embodiments are not limited thereto. In some example embodiments, the neutron absorbing material may partially or entirely comprise one or more structures of the pump casing 302 (e.g., the outer wall structure 302-1, the end structure 302-2, and / or the inner wall structure 302-3), for example, the pump casing 302 (e.g., the outer wall structure 302-1) may include a material that at least partially defines the outer surface 302os of the pump casing 302, and thus the outer surface of the EMP 120, and the material may include a neutron absorbing material, although example embodiments are not limited thereto. In some example embodiments, the neutron absorbing material may be provided as an outer layer of material on the outer surface 302os of the pump casing 302 (e.g., a cylindrical jacket of neutron absorbing material), although example embodiments are not limited thereto.

[0118] While FIG. 4C illustrates a view of the outer sidewall structure 302-1 including the neutron absorbing material 434, it will be understood that the view provided in FIG. 4C and the configuration of the outer sidewall structure 302-1 shown therein may be included in any portion of the pump casing 302, including any portion of the end structure 302-2 and / or the inner sidewall structure 302-3.

[0119] 4A and 4C, in some exemplary embodiments, at least a portion of the pump casing 302 (e.g., outer sidewall structure 302-1 as shown in FIG. 4C) can include concentric cylindrical casing walls defining a casing annulus therebetween, and the neutron absorbing material can be disposed within the casing annulus, for example, as a filler material that partially or completely fills the casing annulus, although exemplary embodiments are not limited thereto. For example, as shown at least in FIG. 4C , at least the outer sidewall structure 302-1 of the pump casing 302 can include concentric cylindrical casing walls 430-1 and 430-2 that collectively define a casing annulus 432 between their respective outer surfaces 430-1os and inner surfaces 430-2is, wherein the inner surface 430-1is of the inner cylindrical casing wall 430-1 defines the inner surface 302is of the portion of the pump casing 302 (e.g., the inner surface of the outer sidewall structure 302-1), and the outer surface 430-2os of the outer cylindrical casing wall 430-2 defines the outer surface 302os of the portion of the pump casing 302, and thus can at least partially define the outer surface of the EMP 120 that is directly exposed to the ambient environment 450 surrounding the EMP 120.

[0120] As shown, the neutron absorber 434 may be disposed in the casing annulus 432 (e.g., partially or fully filled as a filler material). As shown, the neutron absorber 434 may be one or more pieces of material and may have an outer surface 434os in contact with the inner surface 430-2is of the outer cylindrical casing wall 430-2, although example embodiments are not limited thereto. As shown, the neutron absorber 434 may be one or more pieces of material and may have an inner surface 434is in contact with the outer surface 430-1os of the inner cylindrical casing wall 430-1, although example embodiments are not limited thereto. In some exemplary embodiments, one or more of the cylindrical casing walls 430-1 or 430-2 may be omitted from a portion of the pump casing 302 such that the portion of the pump casing 302 (e.g., the outer sidewall structure 302-1 as shown) may be at least partially defined by and / or comprised of the neutron absorber material 434. In some exemplary embodiments, the portion of the pump casing 302 (e.g., the outer sidewall structure 302-1 as shown) may be comprised of a single material that includes the neutron absorber material, either alone or as a mixture of the neutron absorber material and one or more additional materials (e.g., stainless steel).

[0121] Neutron absorber 434 may be configured to absorb ambient neutrons 470 entering EMP 120 from outside EMP 120, e.g., from an ambient environment 450 that at least partially surrounds EMP 120. Ambient environment 450 may be a relatively high temperature (e.g., at least 350° C.), high radiation environment such that ambient neutrons 470 are relatively high-energy neutrons that may wear and / or damage (e.g., degrade and / or activate) internal components of EMP 120 that they come into contact with. Neutron absorber 434 may absorb at least some or all of such ambient neutrons 470 to reduce, minimize, or prevent such ambient neutrons 470 from further penetrating interior 380 of EMP 120 and contacting its internal components. Thus, EMP 120 may be configured to reduce, minimize, or prevent neutron exposure of internal EMP components to ambient neutrons 470 in the surrounding environment 450, thereby improving the useful life, performance, maintenance schedule, and / or decommissioning process of EMP 120.

[0122] Based on the EMP 120 including the neutron absorber 434 therein, the EMP 120 can be configured to be easily and quickly implemented without requiring component program development or extensive research efforts. Based on the inclusion of the neutron absorber 434, the EMP 120 can be configured to reduce, minimize, or prevent pump material degradation (e.g., wear) and / or damage due to neutron exposure to the EM pump components from the high-temperature, high-radiation ambient environment 450. The EMP 120 including the neutron absorber 434 according to any of the exemplary embodiments may have an extended life while located within the reactor pressure vessel 111, may allow for improved reactor design flexibility by allowing the EMP to be located closer to the reactor core, thus reducing reactor vessel system costs, may reduce, minimize, or eliminate expensive irradiation testing to qualify insulation life under temperature, voltage, and radiation conditions inside the reactor, and may reduce, minimize, or prevent neutron exposure to the EM pump components, thereby improving EMP reliability. It can also be implemented in various configurations of EMPs, including self-cooled EMPs, without being limited by design, size, or performance requirements, maintain compatibility in thermophysical and neutronic properties with other pump components and reactor structural materials, and reduce, minimize, or prevent activation of pump components, thereby enabling rapid maintenance and uncomplicated pump decommissioning procedures.

[0123] While at least the exemplary embodiment shown in FIG. 4C illustrates neutron absorbing material included in at least a portion of pump casing 302 (e.g., outer sidewall structure 302-1), exemplary embodiments are not limited thereto, and in some exemplary embodiments, neutron absorbing material may be included in any of the components of EMP 120 (e.g., included in at least one flow duct 310, for example, as filler material and / or as part of an alloy material that at least partially constitutes at least one flow duct).

[0124] 4A, 4C, and 4D, in some exemplary embodiments, the EMP 120 may include a neutron moderator 452 on the outer surface 302os of the pump casing 302. The neutron moderator 452 may at least partially surround, encompass, or otherwise cover some or all of the EMP 120, e.g., the neutron moderator 452 may cover the exposed outer surface 302os of the pump casing 302, with an opening provided in the neutron moderator 452 to allow the power cable 146 to enter the EMP 120 and openings for the inlet 122 and outlet 123 of the EMP 120. The neutron moderator 452 may be provided as a jacket surrounding the outer surface 302os of the pump casing 302 or may be disposed as a filler within a jacket of concentric cylindrical jacket walls (e.g., made of stainless steel) defining a jacket annulus therebetween that may be at least partially filled with the neutron moderator, although example embodiments are not limited thereto, and in some example embodiments, the neutron moderator 452 may be provided as a single material jacket at least partially surrounding the pump casing 302. The neutron moderator material in example embodiments may include one or more of graphite, heavy water, light water, paraffin, polyethylene, concrete, or beryllium.

[0125] In some exemplary embodiments, the neutron moderator 452 may be configured to be disposed between the neutron absorber 434 and the ambient environment 450 and, therefore, may be configured to slow down (e.g., decelerate) ambient neutrons 470-1 received from the ambient environment 450 outside the EMP 120, such that neutrons entering the pump casing 302 from outside the EMP (e.g., the ambient environment 450) become decelerated neutrons 470-2, and the neutron absorber 434 included in the pump casing 302 (e.g., the neutron absorber 434 as shown in FIG. 4C ) may be configured to absorb the decelerated neutrons 470-2. Based on the inclusion of neutron moderator 452 configured to slow down ambient neutrons 470-1 before they reach neutron absorber 434, the probability of absorption of ambient neutrons by neutron absorber 434 may be improved, thereby further reducing, minimizing, or preventing neutron exposure by internal components of EMP 120 (e.g., stator 322, induction coil 320, etc.).

[0126] Figure 5 is a flowchart illustrating a method for operating an EMP according to some example embodiments. The method illustrated in Figure 5 may be implemented with respect to any EMP according to any of the example embodiments. The method illustrated in Figure 5 may be implemented, at least in part, by an EMP control system 150, such as EMP control system 150 shown in Figure 1, and with respect to one or more power sources, such as power source 144 shown in Figure 1.

[0127] 5 , the method may include, at S502, initiating the supply of electrical power (e.g., polyphase electrical power) from the electrical power source 144 (e.g., a polyphase electrical power source) to the EMP 120 (e.g., its multiple induction coils 320). As a result, at S504, the EMP 120 (e.g., the multiple induction coils 320) operates, for example, to cause the liquid metal coolant 190 to flow through the annular fluid passage 312 and cause the liquid metal coolant 190 to flow through the annular fluid passage 312 based on the induction coils 320 generating one or more magnetic fields based on the received electrical power. Operation S502 may include determining whether to initiate (e.g., turn on) the supply of polyphase electrical power from the electrical power source 144. If so, at S502, a control signal may be generated and transmitted to the electrical power source 144 to cause the electrical power source 144 to begin supplying polyphase electrical power to the EMP 120. The control signal may be generated and transmitted by the EMP control system 150. The control signal may cause the power source 144 to begin supplying multi-phase power having a particular (eg, predetermined) frequency, power amplitude (eg, voltage and / or current), phase, and the like.

[0128] In S506, at least partially concurrently with EMP 120 (e.g., multiple induction coils 320) activating to cause liquid metal coolant 190 to flow through annular fluid passage 312, gamma shielding material included in at least one of inner flow duct 310-1 or outer flow duct 310-2 of EMP 120 reduces, minimizes, or prevents penetration of gamma rays 460 from liquid metal coolant 190 within annular fluid passage 312 to interior 380 of EMP 120 outside of annular fluid passage 312 (e.g., induction coil 320, a stator included in EMP 120, circuitry included in EMP 120, conductive elements included in EMP 120, etc.). As a result, the gamma shielding material can reduce, minimize, or prevent wear and / or damage to EMP 120 and / or portions thereof due to gamma rays 460 emitted from liquid metal coolant 190 flowing through annular fluid passage 312. Thus, the gamma shielding material in at least one of the inner flow duct 310-1 or the outer flow duct 310-2 can provide improved performance and / or reliability of the EMP 120, an extended service life of the EMP 120, and a reduced frequency of repairs, maintenance, and / or replacements of the EMP 120 that may otherwise occur due to wear and / or damage caused by gamma rays 460 emitted from the liquid metal coolant 190 flowing through the annular fluid passage 312. The gamma shielding material included in at least one of the inner flow duct 310-1 or the outer flow duct 310-2 of the EMP 120 that reduces, minimizes, or prevents transmission of gamma rays 460 from the liquid metal coolant 190 in the annular fluid passage 312 can be used to reduce, minimize, or prevent transmission of gamma rays 460 from the liquid metal coolant 190 in the annular fluid passage 312 during times when liquid metal coolant 190 flow is not occurring within the annular fluid passage 312 and the liquid metal coolant 190 is present within the annular fluid passage 312 and has no or substantially no flow rate (e.g., mass flow rate and / or volumetric flow rate).

[0129] In S508, at least partially simultaneously with EMP 120 (e.g., multiple induction coils 320) operating to cause liquid metal coolant 190 to flow through annular fluid passage 312, a neutron absorbing material included in pump casing 302 of EMP 120 can absorb neutrons (e.g., ambient neutrons 470) received at pump casing 302 (e.g., outer sidewall structure 302-1) from outside EMP 120 (e.g., ambient environment 450 inside reactor 110 in which EMP 120 is located). As a result, the neutron absorber can reduce, minimize, or prevent wear and / or damage to the EMP 120 and / or portions thereof from neutrons (e.g., ambient neutrons) entering the EMP 120 (e.g., at least the pump casing 302) from the external environment (e.g., the liquid metal coolant 190 and / or structures of the reactor 110 surrounding the EMP 120 within the reactor 110) emitted from the liquid metal coolant 190 flowing through the annular fluid passage 312. Thus, the neutron absorbing material within the pump casing 302 of the EMP 120 may provide improved performance and / or reliability of the EMP 120, an extended useful life of the EMP 120, and a reduced frequency of repair, maintenance, and / or replacement of the EMP 120 that may occur due to wear and / or damage to the EMP 120 due to ambient neutrons 470 received by the EMP 120 and / or entering the EMP 120 from outside the EMP 120 (e.g., the ambient environment 450). It will be understood that in some exemplary embodiments, the neutron absorbing material may not be present in the EMP 120. It will be understood that the neutron absorbing material may absorb the ambient neutrons 470 in the absence of flow of liquid metal coolant 190 through the annular fluid passage 312.

[0130] In some demonstrative embodiments, EMP 120 may include a neutron moderator 452 on the outer surface 302os of pump casing 302, and in S508, the neutron moderator may moderate one or more ambient neutrons 470-1 received at neutron moderator 452 from outside EMP 120 to establish moderated neutrons 470-2, which may then enter at least pump casing 302 of EMP 120 and be absorbed by neutron absorber material therein. As a result, EMP 120 may be configured to sufficiently moderate the ambient neutrons to improve the likelihood of their absorption by the neutron absorber within pump casing 302, thereby reducing, minimizing, or preventing ambient neutrons from entering interior 380 of EMP 120 and potentially wearing and / or damaging any portion of EMP 120, thereby further improving the performance and reliability of EMP 120.

[0131] In S510, a determination may be made as to whether to adjust the supply of electrical power from the power source 144 to the EMP 120 (e.g., adjust the magnitude of the voltage, current, etc. of the electrical power supplied to the EMP 120 to adjust the flow rate of the liquid metal coolant 190 induced by the EMP 120 through the annular fluid passage 312). If so, the adjustment is made in S512. If not, a determination may be made as to whether to terminate or reduce the supply of electrical power from the power source 144 to the EMP 120 in S514. If so, the supply is terminated or reduced in S516, thereby reducing the driving force applied by the EMP 120 to the liquid metal coolant 190 in the annular fluid passage 312, thereby slowing or stopping the flow of the liquid metal coolant 190 through the EMP's annular fluid passage 312.

[0132] Operation S510 may include determining whether to adjust the frequency of the polyphase power supplied by the power source 144 to the EMP 120. If so, in S512, a control signal may be generated and sent to the power source 144 to cause the power source 144 to adjust the frequency of the supply of polyphase power being supplied to the EMP 120. The control signal may be generated and sent by the EMP control system 150. The control signal may cause the power source 144 to adjust the supply frequency of the polyphase power to a new specified frequency.

[0133] Operation S510 may include determining whether to adjust the power amplitude (e.g., voltage and / or current) of the polyphase power supplied by the power source 144 to the EMP 120. If so, in S512, a control signal may be generated and transmitted to the power source 144 to cause the power source 144 to adjust the power amplitude (e.g., voltage and / or current) of the supply of polyphase power being supplied to the EMP 120. The control signal may be generated and transmitted by the EMP control system 150. The control signal may cause the power source 144 to adjust the power amplitude (e.g., voltage and / or current) of the supply of polyphase power to a new specified power amplitude (e.g., voltage and / or current).

[0134] Operation S514 may include determining whether to inhibit (e.g., turn off) the supply of multi-phase power from the power source 144 to the EMP 120. If so, in S516, a control signal may be generated and transmitted to the power source 144 to cause the power source 144 to inhibit the supply of multi-phase power to the EMP 120. The control signal may be generated and transmitted by the EMP control system 150. The control signal may cause the power source 144 to inhibit the supply of multi-phase power to the EMP 120.

[0135] It will be understood that the operations of the method shown in Figure 5 may be performed in any order, including simultaneously. It will be understood that in some exemplary embodiments, any of the operations of the method shown in Figure 5 may be performed independently of one another. In some exemplary embodiments, any of the operations shown in Figure 5 may be omitted, and / or one or more additional operations may be added to the method shown in Figure 5. In some exemplary embodiments, each of the decisions and / or actions shown in FIG. 5 occurs in response to receiving input commands via a user interface (e.g., a keyboard, buttons, touch screen, mouse, etc.) and / or a communication interface (e.g., a wireless network communication receiver), and / or in response to processing sensor data received from one or more sensor devices (e.g., one or more flow meters, such as one or more Venturi flow meters in the suction line 121 and / or return line 124, which may be configured to generate sensor data indicative of the flow rate of the liquid metal coolant 190 through the suction line 121, the return line 124, and / or the EMP 120; one or more pressure sensors, which may be configured to generate sensor data indicative of the pressure of the liquid metal coolant 190 at one or more locations in the suction line 121, the return line 124, and / or the EMP 120, etc.) and / or in response to processing sensor data.

[0136] In some demonstrative embodiments, adjusting the frequency and / or power amplitude of the polyphase power supplied to EMP 120 may include determining a particular frequency and / or power amplitude and controlling a polyphase power source (e.g., power source 144) to supply polyphase power having the particular frequency and / or power amplitude to EMP 120. Determining the particular frequency and / or power amplitude may be performed in response to receiving an input command specifying the particular frequency and / or power amplitude of the polyphase power supplied to EMP 120 and / or in response to processing sensor data received from one or more sensor devices (e.g., one or more flow meters, such as one or more Venturi flow meters, that can be configured to generate sensor data indicative of a flow rate of liquid metal coolant 190 through suction line 121, return line 124, and / or EMP 120, one or more pressure sensors that can be configured to generate sensor data indicative of a pressure of liquid metal coolant 190 at one or more locations within suction line 121, return line 124, and / or EMP 120, etc.).

[0137] The input commands and / or sensor data may be processed to determine a desired or target flow rate and / or pressure rise distribution of the liquid metal coolant through at least EMP 120, an actual flow rate and / or pressure rise distribution of the liquid metal coolant through at least EMP 120 and / or primary coolant loop 119, etc. In some exemplary embodiments, if the actual flow rate and / or pressure rise distribution is determined based on processing of the sensor data, the target flow rate and / or pressure rise distribution may be determined based on comparing the actual flow rate and / or pressure rise distribution to a desired, threshold, or target flow rate and / or pressure rise distribution, which may be stored in a memory and / or database. The comparison may include determining a new target flow rate and / or pressure rise distribution based on a determination that the actual flow rate and / or pressure rise distribution exceeds one or more threshold flow rate and / or pressure rise distributions.

[0138] Determining the particular frequency and / or power amplitude may include, for example, in response to processing input commands and / or received sensor data (e.g., in response to determining the desired, target, and / or actual flow rate and / or pressure rise distribution of the liquid metal coolant through at least the EMP 120 and / or primary coolant loop 119, etc.), accessing an empirically generated look-up table relating particular parameters (e.g., frequency and / or power amplitude, start or inhibit state, etc.) of the multi-phase power supplied to the EMP to achieve the associated liquid metal coolant 190 flow rate and / or pressure rise distribution with the actual, target, and / or desired liquid metal coolant 190 flow rate and / or pressure rise distribution within the EMP 120. In some examples, in response to receiving an input of a desired, target, and / or actual liquid metal coolant 190 flow rate and / or pressure rise distribution within EMP 120, a lookup table may be accessed to identify certain parameters (e.g., frequency and / or power amplitude, onset or inhibit state, etc.) of the multi-phase power supplied by the multi-phase power source to the EMP to achieve the desired and / or target liquid metal coolant flow rate and / or pressure rise distribution. Operations S504, S512, and / or S516 may include sending a control signal to the multi-phase power source to adjust the multi-phase power supplied to EMP 120 according to the certain parameters (e.g., frequency and / or power amplitude, onset or inhibit state, etc.) of the multi-phase power supplied to the corresponding EMP to achieve the desired and / or target liquid metal coolant flow rate and / or pressure rise distribution.

[0139] 6 is a flow chart illustrating a method for configuring S600 a nuclear reactor to improve performance and reliability of liquid metal coolant flow circulation and / or control within the nuclear reactor, according to some example embodiments. The configuration may be performed with respect to any example embodiment of a nuclear reactor included herein, including the nuclear reactor 110 illustrated in FIG.

[0140] In S602, configuration S600 may include installing EMP 120 in primary coolant loop 119 within reactor pressure vessel 111. EMP 120 may be any of the EMPs 120 according to any of the example embodiments. The installation may be performed by a human operator. Such installation may include connecting an inlet 122 of EMP 120 to a suction line 121 of primary coolant loop 119 and connecting an outlet 123 of EMP 120 to a return line 124 of primary coolant loop 119. The installation may include connecting a pump casing 302 of EMP 120 to a structural support member of reactor 110 to structurally connect EMP 120 to reactor pressure vessel 111, core inlet plenum 118, reactor core 112, primary heat exchanger 114, suction reservoir 116, or any combination thereof.

[0141] In S604, configuration S600 may include electrically coupling EMP 120 to power source 144 (e.g., a poly-phase power source configured to provide poly-phase power), thereby electrically connecting EMP 120 to power source 144. The coupling may be performed by a human operator. The electrical coupling in S604 may include electrically connecting multiple induction coils 320 of EMP 120 to power cable 146, which extends from EMP 120 via power conductor 180, or an extension cord, to at least the exterior of reactor pressure vessel 111 through opening 182 (e.g., penetration) that penetrates outer wall 111S of reactor pressure vessel 111. Power cable 146 may be configured to connect power source 144 to EMP 120.

[0142] At S606, configuration S600 may include coupling (e.g., electrically coupling and / or communicatively coupling) EMP 120 to one or more EMP control systems (also referred to herein as one or more control systems). The coupling may be performed by a human operator. The coupling may include communicatively coupling EMP 120 to one or more portions of EMP control system 150 via one or more communication lines, electrically coupling power source 144 to EMP control system 150, thereby indirectly communicatively coupling EMP control system 150 to EMP 120 via power source 144 via one or more communication lines, power lines, etc. The EMP control system 150 may include a memory (e.g., a solid-state drive or SSD) that stores a program of instructions and a processor (e.g., a central processing unit or CPU) configured to execute the program of instructions to independently control the EMP 120 based on controlling the power (e.g., polyphase power) provided by the power supply 144, and thus control the flow of liquid metal coolant through at least the annular fluid passage of the EMP 120, and therefore the flow of liquid metal coolant through the primary coolant loop 119.

[0143] While numerous exemplary embodiments are disclosed herein, it should be understood that other variations are possible. Such variations are not to be considered a departure from the spirit and scope of the present disclosure, and all such modifications that would be obvious to one of ordinary skill in the art are intended to be included within the scope of the following claims. In addition, although steps are disclosed herein, it should be understood that the described elements of the steps may be implemented in a different order, using different selected elements, combinations thereof, etc. For example, some exemplary embodiments of the disclosed processes may be implemented using fewer elements than those of the processes shown and described, and some exemplary embodiments of the disclosed processes may be implemented using more elements than those of the processes shown and described.

Claims

1. An electromagnetic pump (EMP), A pump casing having a longitudinal axis extending in the longitudinal direction, the pump casing defining at least partially the interior of the EMP, A concentric inner flow duct and an outer flow duct extend coaxially with the longitudinal axis and collectively define an annular fluid passage that extends coaxially with the longitudinal axis, A plurality of induction coils located inside the EMP and configured to be electrically connected to a power source, wherein the plurality of induction coils are configured to control the flow of liquid metal coolant through the annular fluid passage based on the power received from the power source, Equipped with, At least the outer flow duct includes a gamma shielding material configured to block gamma rays emitted from the liquid metal coolant flowing through the annular fluid passage from entering the interior of the EMP from the annular fluid passage, The outer flow duct includes a first concentric cylindrical duct wall defining a first duct annular portion between first concentric cylindrical duct walls, the first concentric cylindrical duct wall includes a first outer cylindrical duct wall and a first inner cylindrical duct wall, the first concentric cylindrical duct wall defines the first duct annular portion between the inner surface of the first outer cylindrical duct wall and the outer surface of the first inner cylindrical duct wall, and the inner surface of the first inner cylindrical duct wall partially defines the annular fluid passage. The gamma shielding material is located within the first duct annular portion between the first outer cylindrical duct wall and the first inner cylindrical duct wall, such that the first inner cylindrical duct wall is located between the gamma shielding material and the annular fluid passage. The gamma shielding material is a filler material in the annular portion of the first duct. Electromagnetic pump (EMP).

2. The EMP according to claim 1, wherein the pump casing includes a neutron absorber, and the neutron absorber is configured to absorb neutrons entering the pump casing from outside the EMP.

3. The EMP according to claim 2, wherein the pump casing includes concentric cylindrical housing walls defining a housing annular portion therein, and the neutron absorbing material is disposed within the housing annular portion.

4. The EMP according to claim 2, further comprising a neutron moderator on the outer surface of the pump casing, wherein the neutron moderator is configured to slow down neutrons received from outside the EMP so that neutrons entering the pump casing from outside the EMP become slowed neutrons, and the neutron absorber is configured to absorb the slowed neutrons.

5. The EMP according to claim 1, wherein the plurality of induction coils include at least one of an inner induction coil disposed within a central region at least partially defined by the inner surface of the inner flow duct, and an outer induction coil disposed within an annular region at least partially defined between the outer surface of the outer flow duct and the inner surface of the pump casing.

6. A method for activating an EMP as described in claim 1, The steps include controlling the power supply to the EMP to generate one or more magnetic fields in the plurality of induction coils and to guide the flow of liquid metal coolant through the annular fluid passage, The steps include: using the gamma shielding material contained in the outer flow duct to block gamma rays emitted from the liquid metal coolant in the annular fluid passage from entering the EMP located outside the annular fluid passage; A method that includes this.

7. The method according to claim 6, wherein the pump casing includes a neutron absorber, the neutron absorber is configured to absorb neutrons entering the pump casing from outside the EMP, and the method further includes the step of absorbing neutrons received by the pump casing from outside the EMP with the neutron absorber.

8. A method for configuring a nuclear reactor to improve flow rate control of a liquid metal coolant within the reactor, The steps include installing the EMP described in claim 1 in the primary coolant loop in the reactor pressure vessel of the reactor, The steps include electrically connecting the EMP to the power supply via a power cable, A step of connecting the EMP to a control system in a communicative manner, wherein the control system includes a memory for storing a program of instructions and a processor configured to execute the program of instructions to control the flow of liquid metal coolant through the primary coolant loop, based on controlling the supply of power supplied from the power source to the EMP; A method that includes this.

9. A nuclear reactor configured to be cooled by liquid metal circulation, The reactor pressure vessel and The reactor core in the reactor pressure vessel, An EMP within the reactor pressure vessel according to claim 1, configured to circulate a flow of liquid metal coolant through a primary coolant loop including the core, A nuclear reactor equipped with [a specific feature / equipment].

10. The reactor according to claim 9, further comprising a control system configured to control the power supply to control the power supply to the EMP in order to control the flow of liquid metal coolant through the primary coolant loop.

11. The gamma shielding material blocks incident gamma-ray photons emitted from the liquid metal coolant flowing through the annular fluid passage. Photoelectric absorption of gamma rays by the gamma shielding material, comprising the complete transfer of energy from the incident gamma-ray photon to the atomic electrons of the gamma shielding material, The scattering of gamma rays by the gamma shielding material, wherein the scattering includes the transfer of a portion of the energy of the incident gamma-ray photon to the atomic electrons of the gamma shielding material, thereby causing the gamma shielding material to cause the incident gamma-ray photon to either engage in further scattering or absorption interactions with the gamma shielding material, or to exit the gamma shielding material with reduced energy. Pair production, wherein the pair production includes an interaction between the incident gamma-ray photon and the nucleus of an atom of the gamma-shielding material, resulting in the production of a beta particle and a positron that undergoes an annihilation reaction with an electron to produce two lower-energy gamma rays. The EMP according to claim 1, configured to be blocked based on at least one of the following.

12. The EMP according to claim 1, wherein the gamma shielding material comprises one or more of lead, tin, bismuth, tungsten, water, paraffin borate, or polyethylene borate.

13. The EMP according to claim 2, wherein the neutron absorber comprises one or more of gadolinium, cadmium, gadolinium oxide, lithium hafnium, europium, gadolinium stainless steel, silver, xenon, or indium.

14. The EMP according to claim 1, wherein each of the inner flow duct and the outer flow duct includes at least one gamma shielding material configured to block gamma rays emitted from the liquid metal coolant flowing through the annular fluid passage from entering the interior of the EMP from the annular fluid passage.

15. The inner flow duct includes a second concentric cylindrical duct wall defining a second duct annular portion between the second concentric cylindrical duct walls, the second concentric cylindrical duct wall includes a second outer cylindrical duct wall and a second inner cylindrical duct wall, the second concentric cylindrical duct wall defining the second duct annular portion between the inner surface of the second outer cylindrical duct wall and the outer surface of the second inner cylindrical duct wall, The outer flow duct and the inner flow duct collectively define the annular fluid passage between the inner surface of the first inner cylindrical duct wall of the outer flow duct and the outer surface of the second outer cylindrical duct wall of the inner flow duct. The additional gamma shielding material is located within the second duct annular portion between the second outer cylindrical duct wall and the second inner cylindrical duct wall, such that the second outer cylindrical duct wall is located between the additional gamma shielding material and the annular fluid passage. The additional gamma shielding material in the second duct annular section and the gamma shielding material in the first duct annular section are the same gamma shielding material. The aforementioned additional gamma shielding material is a filler material within the annular portion of the second duct. The EMP according to claim 1.

16. The EMP according to claim 1, wherein the gamma shielding material comprises one or more of water, paraffin borate, or polyethylene borate.

17. The EMP according to claim 15, wherein the gamma shielding material and the additional gamma shielding material are each the same one or more of water, paraffin borate, or polyethylene borate.

18. The EMP according to claim 3, wherein the neutron absorbing material is a filler material in the annular portion of the housing.

19. The EMP according to claim 1, wherein the gamma shielding material does not provide structural integrity to the outer flow duct.

20. The EMP according to claim 15, wherein the additional gamma shielding material does not provide structural integrity to the inner flow duct.

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