Cartridge core barrel for nuclear reactor

Abstract

To reduce potential relative movement between a reactor core and control elements.SOLUTION: A method of constructing a nuclear reactor is provided, comprising attaching a core barrel to a control element support structure, where the core barrel is hung from the control element support structure configured to support the weight of each of one or more control elements, the core barrel, and a reactor core.SELECTED DRAWING: Figure 11

Description

Detailed Description of the Invention

[0001] [Cross - Reference to Related Applications] This application claims the benefit of U.S. Patent Application No. 17 / 164,820, entitled "CARTRIDGE CORE BARREL FOR NUCLEAR REACTOR", filed on February 1, 2021, which claims the priority of Provisional Patent Application No. 63 / 066,785, entitled "CARTRIDGE CORE BARREL FOR NUCLEAR REACTOR", filed on August 17, 2020. The entire content thereof is incorporated herein by reference.

[0002] [Background] Most nuclear reactors have a core in which fuel elements and control elements are supported in various interrelated arrangements to support the critical reactivity and control the output of the nuclear reactor. The coolant is typically forced through passages between the fuel elements and the control elements, and thus the heat generated by the nuclear - fission fuel elements is transferred to a heat exchanger for beneficial purposes.

[0003] In some cases, molten metal is used as the coolant, and in some cases, the molten metal is sodium. In some nuclear reactors (e.g., pool - type nuclear reactors where the core is immersed in a pool of coolant held within a reactor vessel), the core is often supported by the reactor vessel, while the control elements are often supported from a deck of a vessel head that surrounds the upper end of the reactor vessel.

[0004] This control - element support arrangement is often preferred from a safety perspective. For example, if the control - element support structure fails, the control element will fall into the reactor vessel, reducing the reactivity within the core. Typically, like the in - vessel handling systems for fuel elements and reactivity elements, the weight of the core, along with the fuel elements and reactivity elements, is supported by the reactor vessel.

[0005] In addition to the weight of the reactor core, the vessel supports the weight of the coolant contained therein. Therefore, the vessel must be robust enough to support not only the loads applied in the static state but also the loads during seismic events where loads much greater than the static state can be applied.

[0006] Furthermore, any relative movement between the reactor core and the control element can affect the reactivity within the reactor core, and thus the reactor is designed to minimize the relative movement between the reactor core and the control element. When the reactor vessel is supported from the side or its bottom and the coolant inventory is displaced by an earthquake event or the like, the flexibility of the reactor vessel allows the reactor core to move relative to the control element suspended from the vessel head. Therefore, it can cause swings in the reactivity coefficient (Keff) in both positive and negative directions.

[0007] 〔Overview〕 According to some embodiments, a reactor arrangement is described in which the reactor vessel is suspended from the reactor head. However, the weight of the reactor core does not have to be supported by the reactor head; rather, it may be directly transmitted to a support structure located outside the reactor vessel and supported by the ground. In some examples, the reactor core is supported by a cartridge suspended from the reactor vessel head, and thus the load paths for both the reactor core and the control element are coupled to a common support structure. This reduces the potential relative movement between the reactor core and the control element.

[0008] According to some embodiments, a reactor core support system includes a support cylinder having an upper portion and a lower portion, and a mount at the upper portion that engages the reactor vessel head and supports the weight of the support cylinder from the reactor vessel head. The support cylinder is suspended from the reactor vessel head.

[0009] In some cases, the reactor core is within the support cylinder. The support cylinder and the reactor core may be pre-assembled and transported to the reactor installation site.

[0010] In some examples, the fuel element handling system is disposed within the support cylinder. Further, the control element support system may be within the support cylinder.

[0011] In some embodiments, the support cylinder and the control element drive system share a common load path. That is, the weights of the support cylinder and the control element drive system are supported by the same structure.

[0012] For example, both the support cylinder and the control element drive system may be suspended from a portion of the reactor vessel head.

[0013] In some cases, the core support disposed within the support cylinder does not transmit a load to the reactor vessel. For example, the core may be disposed within the support cylinder, and the weight of the core may be supported by the reactor vessel head.

[0014] According to some embodiments, a method for constructing a nuclear reactor includes manufacturing a reactor vessel in a manufacturing facility, manufacturing a cartridge core barrel in the manufacturing facility, manufacturing a core in the manufacturing facility, manufacturing a control element drive system in the manufacturing facility, assembling the control element drive system and the core within the cartridge core barrel in the manufacturing facility to form a core module, and transporting the core module to a construction site.

[0015] The method may further include transporting the reactor vessel to the construction site. In some cases, the method may further include installing the reactor vessel in a nuclear reactor building. The method may further include disposing the nuclear reactor module inside the reactor vessel.

[0016] The method of constructing a nuclear reactor may, in some cases, further include the step of coupling the core module to a first portion of the nuclear reactor vessel head. In some cases, the method includes the step of coupling the control element drive system to the first portion of the nuclear reactor vessel head.

[0017] According to some embodiments, a lower core support structure for a nuclear reactor core includes a conical support portion, a cylindrical support portion coupled to the conical support portion by a transition portion, and one or more vertical ribs.

[0018] The one or more vertical ribs may be coupled to the conical support portion. The conical support portion may include a conical tension skirt having a large-diameter peripheral portion coupled to the cylindrical support portion. In some cases, the one or more vertical ribs are coupled to an upper surface of the conical tension skirt.

[0019] [Brief Description of the Drawings] FIG. 1 is a schematic diagram of a nuclear reactor support structure according to some embodiments; FIG. 2 shows a lower core support structure for a core-vessel interface according to some embodiments; FIG. 3 shows a lower core support structure for a core-vessel interface according to some embodiments; FIG. 4 shows a lower core support structure having a suspended tension skirt for a core-vessel interface according to some embodiments; FIG. 5 shows a lower core support structure having a plurality of ribs according to some embodiments; FIG. 6 shows a lower core support structure independent of a nuclear reactor vessel according to some embodiments; FIG. 7 shows a lower core support structure in a bottom-supported vessel configuration according to some embodiments; FIG. 8 shows a core support structure configured to be suspended from a nuclear reactor head according to some embodiments; FIG. 9 shows a core support structure that utilizes a cartridge to couple a core support to a control rod support, according to some embodiments; FIG. 10 shows a load path through a lower core support structure and a reactor vessel, according to some embodiments; FIG. 11 shows a cartridge core support structure that supports a core independently of a reactor vessel, according to some embodiments; FIG. 12 shows a cartridge module, according to some embodiments.

[0020] 〔DETAILED DESCRIPTION〕 The present disclosure generally relates to an apparatus for a lower core support, such as a support for a reactor vessel (which may be a conical support that transitions to a cylindrical support of the reactor vessel in some cases), or a support for a nuclear reactor core. In some cases, additional stiffness, rigidity, and support are provided by a plurality of vertical ribs within the conical support section.

[0021] In some cases, the core is supported from below by a plurality of ribs, skirts, or platforms, etc. In some embodiments, the core is supported by a rim. The core may have a structure that engages an upper rim of the core and is suspended from the support by that rim. In some cases, a vertical cylinder includes a core support structure and a plurality of core baffles. The core may be inserted from the upper end of the reactor and supported by a reactor head. In some embodiments, the disclosed configurations and support structures facilitate the transportation of pre-manufactured and assembled, or partially assembled, components, and the final assembly of such components at the nuclear reactor installation site.

[0022] According to some embodiments, the structural cylinder supports the load and transfers the load to the reactor head. According to some embodiments, a control package and a core control package may be manufactured and then lowered to a predetermined position within the structural cylinder. The structural cylinder may support the loads of the control package and the core control package.

[0023] The support cylinder may be manufactured at a manufacturing facility and may include a core barrel and core components that are already installed before the support cylinder is transported to the reactor installation site. The support cylinder may further have a rotary plug, ports, and other components pre-installed before transportation to facilitate later assembly. This improves accuracy, tolerances, and manufacturing and assembly times.

[0024] The following description is useful in the design and configuration of a sodium-cooled fast reactor (SFR), but many of the concepts disclosed herein may be equally applicable to other reactor types. The present disclosure should not be limited to SFR technology unless otherwise specified.

[0025] Figure 1 shows a core support structure (CSS) for a reactor core. The reactor includes a core 102 located within a reactor vessel 104. The reactor vessel 104 typically has its lower end closed by a bottom head 106 coupled to a cylindrical portion 108. A vessel head 110 is fitted to the top of the cylindrical portion 108 to close the reactor vessel 104 and further support the reactor internal structures (such as a rotary plug, core support structure, flow-directing members, control element handling system, fuel element handling system, and other internal vessel equipment).

[0026] In many reactors, the reactor vessel 104 is suspended from the reactor head 110. Also, the reactor head 110 is supported by a structure that forms part of the building in which the reactor is housed. For example, a plurality of support structures 112, which may be made of concrete, are connected to a foundation 114. The plurality of support structures 112 further support the reactor head 110 such that the weight of the reactor head is supported in a compressed state by the plurality of support structures 112. The reactor vessel 104 is typically suspended from the reactor head 110, and thus its weight is also supported by the plurality of support structures 112 that transfer the load to the foundation 114.

[0027] The reactor vessel 104 houses the reactor internal structure. In some cases, the reactor internal structure includes a lower core support structure (not shown), an upper core support structure, and an in-core instrumentation support structure. The internal structure is configured to support, align, and guide the core components, direct the flow of coolant from core component to core component, and guide and support the in-core instrumentation. The lower core support structure is typically coupled to the core 102 and transmits the weight of the core 102 to the bottom head 106 of the reactor vessel 104. The lower core support structure may be columns, piers, or other supports under the core that enable the core 102 to be supported by the bottom head 106 of the reactor vessel 104.

[0028] The core barrel supports and houses the fuel elements and directs the flow of coolant. In some cases, the core barrel is suspended from the upper ledge of the reactor vessel. In some cases, the core barrel is capable of thermal expansion in the radial and axial directions. However, the lateral movement of the core barrel is restricted to suppress misalignment of the fuel elements and control elements. The core barrel may be coupled to the reactor vessel via any suitable structure that enables the weight of the core barrel to be supported by the reactor vessel that suspends the core barrel.

[0029] With respect to FIG. 2, the lower core support 200 includes a conical support 202 that transitions to a cylinder 204 that joins the bottom reactor vessel head. One or more vertical ribs 206 serve to locate and support the ex-core barrel shielding and the flow guide. Further, the vertical ribs 206 serve to couple the core support structure and the core-vessel interface structure into a single structure. This may be transportable as a unit. This facilitates manufacturing the lower core support structure in a factory and transporting the core support structure as an assembled unit to the construction site.

[0030] Figure 3 shows another example of the lower core support structure 300 integrated with the reactor vessel bottom head 302. The core support structure 300 includes a plurality of ribs 304 to enhance the rigidity and lateral stability of the core support structure 300. The grid plate 306 is supported by the ribs 304 and supports the core placed thereon. The reactor vessel bottom head 302 is suspended from the cylindrical portion of the reactor vessel.

[0031] Integrating the lower core support structure 300 with the reactor vessel bottom head provides several advantages. For example, this reduces the number of components and assemblies, enables compatibility with the Reactor Vessel Auxiliary Cooling System (RVACS), and provides a level of lateral stability for supporting the core.

[0032] Figure 4 shows another example of the lower core support structure 400 where the conical tension skirt 402 supports the grid plate structure 404. The core is supported on the grid plate structure 404. The load of the core is directly transmitted through the conical tension skirt 402 to the cylindrical portion 406 of the reactor vessel. In some cases, this configuration avoids the load of the core being applied to the reactor vessel bottom head 408. Instead, the load of the core is directly transmitted to the cylindrical portion 406 of the reactor vessel.

[0033] As a result, relatively simple manufacturing becomes possible. The conical tension skirt 402 improves the need for internal support from the bottom reactor vessel head 408 and sends the load of the core and internal structures through the tension to the cylindrical portion 406 of the reactor vessel.

[0034] Figure 5 shows an alternative configuration of the lower core support structure 500, which is similar to the structure shown in Figure 4, with a plurality of ribs 502 added above the conical tension skirt 402. The plurality of ribs 502 support the flow guide, provide coolant channels, and provide additional rigidity.

[0035] FIG. 6 shows an alternative configuration of the lower core support 600. The lower core support 600 includes a cylindrical portion 602 and a conical tension skirt 604 hanging down from the cylindrical portion 602.

[0036] The lower core support 600 may, in some cases, be independent of the reactor vessel 606 and may reduce the stress on the reactor vessel 606. In some cases, the lower core support 600 may be attached to the reactor vessel 606 by welding to provide a tight surface contact, disperse the stress, improve the rigidity, and disperse the core load to the cylindrical portion of the reactor vessel 606. In some embodiments, the core is coupled to the lower core support 600 at a manufacturing facility (e.g., a factory), etc., and the entire core with the lower core support 600 can be lowered into the reactor vessel and assembled to the reactor vessel at the construction site.

[0037] FIG. 7 illustrates an alternative of the lower core support 700 in which the core load path is transmitted to the bottom support. The reactor vessel 702 has a cylindrical portion 704 coupled to a bottom vessel head 706. In some cases, the bottom vessel head 706 is placed on one or more supports to transmit the weight of the reactor vessel 702 downward, ultimately to the foundation of the reactor building. In some cases, the lower core support 700 is coupled to the reactor vessel 702, and the core load is similarly transmitted to the supports and ultimately downward to the foundation of the reactor building. In an embodiment where the core load is transmitted downward to a support below the reactor vessel 702, the core load may not be supported by the reactor vessel 702. Thus, the flexibility of the reactor vessel 702 reduces the impact on the alignment of the control elements and the core.

[0038] Furthermore, the lateral support of the core includes a core structure substantially below that is tied to the same support that supports the reactor vessel 702. This not only significantly reduces the load path of the core load but also supports the core substantially along its center of gravity, providing a robust core support.

[0039] Referring to FIGS. 8 and 9, the configuration of a cartridge 800 is shown in which the core load is vertically supported through the core barrel. The cartridge 800 is generally a cylindrical chamber 802 that allows the nuclear reactor core to be inserted from the top. The cartridge 800 includes a cooperating bottom support structure 804 that joins with a lower core support 806 held by the nuclear reactor vessel bottom head 808. The cooperating lower core support structure 804 facilitates lowering the cartridge 800 into the nuclear reactor vessel 810 and positioning the cartridge 800 relative to the vessel bottom head 808.

[0040] In some cases, the core load is supported by the cartridge 800 at a separated portion of the nuclear reactor head. In some cases, the cartridge 800 also supports and houses a rotary plug assembly. By utilizing a cartridge 800 as shown and described, factory manufacturing and on-site assembly are simplified because the cartridge 800 can be manufactured at a manufacturing facility and assembled with a pre-installed core and internal structures prior to transportation.

[0041] In some cases, the cartridge 800 is supported from above by the nuclear reactor head. This provides the additional advantage of coupling the core to the same load path as the control element support. Thus, any differential movement between the core and the control elements due to seismic events and the like is further reduced.

[0042] In the example shown, the core support is directly coupled to the control element support. This further reduces the importance of the nuclear reactor vessel in providing support to the core. Thus, the precision required in the manufacture and assembly of the core with respect to the nuclear reactor vessel 810 is reduced.

[0043] The nuclear reactor vessel 810 can include additional structures required for operation, such as one or more heat exchangers 812 and one or more pumps 814 for circulating coolant through the nuclear reactor vessel and the core.

[0044] According to some embodiments, a load chain including a core, a cartridge, and a reactor vessel head can be manufactured within a manufacturing facility and transported to a construction site as a module for final assembly. This not only reduces the required on-site manufacturing work but also improves efficiency because the reactor vessel, the vessel head, and the internal structures can be lifted and placed inside the reactor building. In some cases, the core and the cartridge may be manufactured as a module and transported to the construction site for final assembly together with the reactor vessel head, which is a separate (split) module.

[0045] In addition, the illustrated cartridge configuration 800 further decouples the nuclear heat and control modules from the heat transfer function, such that the standard central cartridge 800 and the core module can be inserted into various reactor configurations with minimal changes. In other words, the entire cartridge 800, including the core, the control elements, and the in-core structures, can be removed from the reactor and another cartridge 800 can be installed in its place.

[0046] FIG. 10 shows a schematic view of a reactor 1000 including a reactor vessel 1002, a core barrel 1004, and a core 1006. The reactor vessel 1002 further includes a vessel bottom head 1008 and a vessel head 1010. The vessel head 1010 includes a control element support structure 1012 that supports control elements 1014. The control elements 1014 can be used to control the reactivity within the core 1006.

[0047] In the illustrated embodiment, the weight of the core is held by the core barrel 1004. Also, the core barrel 1004 is supported by a lower core support 1016 that transmits the core load to the reactor vessel bottom head 1008. In some cases, the reactor vessel 1002 is supported by mounts such as flanges formed on the vessel head 1010. The reactor vessel 1002 is suspended from the vessel head 1010. Thus, the weight of the reactor vessel is supported by the vessel head 1010 together with the core and the core barrel. In some examples, there may be additional support structures, for example, below the reactor vessel 1002 or adjacent to the core barrel 1004 to support against lateral loads.

[0048] One area of concern in reactor construction is the response of the in-reactor structures to seismic events. For example, due to a seismic event, the reactor vessel 1002 can move both laterally and axially in response to seismic forces. Similarly, the control element 1014 can move in response to seismic forces. If there is differential movement between the control element 1014 and the reactor vessel 1002, the reactivity within the core 1006 is affected. Additionally, manufacturing the control element support 1012 and the configuration for aligning the core 1006 with the control element 1014 requires tight tolerances and high-quality manufacturing to ensure safe and predictable reactor operation.

[0049] In the illustrated embodiment, the weight of the reactor core is supported by the reactor vessel 1002. On the other hand, the weight of the control element 1014 is held by the control element support 1012 that forms part of the vessel head 1010. In a seismic event that causes movement of the reactor vessel 1002, the movement around the reactor vessel head 1010 is substantially converted into lateral movement of the control element 1014 around the pivot point located at the vessel head 1010. On the other hand, the reactor core 1006 undergoes movement related to the height of the reactor vessel 1002. That is, the reactor core 1002 undergoes movement related to the vessel bottom head 1008 having a movement magnitude proportional to the height of the reactor vessel 1002. In many cases, a seismic event tends to cause a greater lateral movement of the reactor core 1006 supported by the reactor vessel 1002 compared to the movement of the control element 1014. The differential movement between the reactor core and the control element 1014 can cause undesirable and unpredictable reactivity fluctuations.

[0050] FIG. 11 shows a schematic view of a nuclear reactor 1100 including a reactor vessel 1002, a core cartridge 1102, and a reactor core 1006. The reactor vessel 1002 further includes a vessel bottom head 1008 and a vessel head 1010. The vessel head 1010 includes a control element support structure 1012 that holds one or more control elements 1014. The control element support structure 1012 is coupled to the core cartridge 1102 such that the core cartridge 1102 is suspended from the control element support structure 1012. Thus, the load paths of both the reactor core 1006 and the control element 1014 are coupled to each other by sharing a common support structure 1012 that supports both the control element 1014 and the reactor core 1006. Thereby, the differential movement between the control element 1014 and the reactor core 1006, for example in response to a seismic event, is significantly reduced.

[0051] Furthermore, the illustrated configuration provides a cartridge 1102 that can be manufactured at a factory, transported to a construction site, and lowered into the reactor vessel even after the reactor vessel 1002 has been installed within the reactor building. In some cases, the cartridge 1102 may be manufactured at the factory to include the core 1006 and the in-core structures prior to transportation. This improves the accuracy in manufacturing delicate components, reduces the amount of on-site manufacturing work, and significantly reduces the time required to install components on-site.

[0052] Furthermore, the illustrated embodiment reduces complexity and eliminates the reliance on the walls of the reactor vessel 1002 to support the core 1006. As described herein, the first cartridge 1102 may be removed from the reactor vessel 1002 and replaced with a second cartridge 1102. In some embodiments, the second cartridge 1102 has a different configuration than the first cartridge.

[0053] FIG. 12 shows a cartridge core barrel 1200 including a generally cylindrical cartridge 1202, a core 1006, and a control element support 1204. The control element support 1204 may include a plurality of openings that allow the control elements 1014 to be selectively inserted into and withdrawn from the core 1006. The cartridge core barrel 1200 includes a mounting structure 1206 that may include one or more flanges that engage a cooperating structure on the reactor vessel head. Thus, the cartridge core barrel 1200 is suspended from the reactor head. The cartridge core barrel 1200 may further include a lower core support 1208 that can cooperate with a mating structure on the reactor vessel bottom head to provide additional support to the core barrel 1200.

[0054] In some embodiments, the cartridge core barrel 1200 may be manufactured in a manufacturing facility and transported to the construction site as a module. The core barrel 1200 may be manufactured to include the core 1006, any in-core structures, a control element drive system, and a control element support 1204. The load paths of the control element 1014 and the core 1006 are coupled together such that movement associated with the reactor vessel head transmits movement to both the core 1006 and the control element 1014 in the same direction and magnitude. Thereby, the control element 1014 can remain aligned with the core 1006 to a level not heretofore achieved in reactors where the core load path and the control element are not coupled to each other via a common load path.

[0055] In addition, the cartridge core barrel 1200 may be manufactured as a module and installed into the reactor vessel after the reactor vessel has been installed within the reactor building. Thereby, the efficiency of assembly is improved, on-site manufacturing is reduced, and tolerances are increased by manufacturing and assembling the module within the manufacturing facility. According to some embodiments, the cartridge core barrel 1200 may be manufactured as a module that includes a core, a rotating plug, and a control element support structure. This module is manufactured within a factory to have tight tolerances that are very difficult to achieve with on-site manufacturing techniques, and thereafter, the module with internal elements already installed may be transported to the construction site for installation.

[0056] In some embodiments, the cartridge core barrel 1200 may be a single module, and the reactor vessel may be a separate module. In some cases, the reactor vessel may be sliced into segments along its longitudinal direction to facilitate transportation and assembly. For example, the reactor vessel may be divided into cylindrical segments having appropriate lengths (e.g., 8 feet, 10 feet, 12 feet, or 15 feet, or more) to facilitate transporting the reactor vessel to the construction site. The plurality of segments may be joined to each other on site. For example, the plurality of segments may be joined to each other at a predetermined position within the reactor building by aligning and installing a first segment at a predetermined position within the reactor building and then attaching a second segment to the first segment. Once the reactor vessel is assembled and installed within the reactor building, the cartridge core barrel 1200 may be lowered into and disposed within the reactor vessel with the assistance of the lower core support 1208. A support structure for positioning control elements relative to the core requires a high-precision manufacturing process. This is much more easily satisfied by providing the cartridge core barrel 1200 that is manufactured at a manufacturing plant and transported to the construction site. The cartridge core barrel 1200 may, in some cases, include a pre-assembled core and other internal elements prior to shipment. This significantly simplifies construction, improves accuracy, and eliminates the dependence on the reactor vessel to support the weight of the core. By removing the reactor vessel from the core's load path, the reactor vessel may be manufactured with looser tolerances and less robustness. This leads to a reduction in the time and cost for manufacturing the reactor vessel. In other words, the reactor vessel is decoupled from the cartridge core barrel 1200 and the core 1006. In some cases, the reactor vessel may not be involved in supporting the core. However, in some embodiments, the reactor vessel may include one or more spacers within the annulus between the reactor vessel and the cartridge core barrel to provide radial lateral stability.

[0057] The cartridge core barrel 1200 may incorporate any suitable downward core support 1208 (e.g., any structure illustrated and described in connection with FIGS. 2-7). Further, the concepts presented herein may be applicable to any reactor type and are particularly suitable for reactors that rely on near atmospheric pressure conditions.

[0058] This disclosure presents exemplary embodiments. Therefore, this disclosure is not intended to limit, in any respect, the scope of the embodiments of this disclosure and the appended claims. The embodiments have been described above with the aid of functional building blocks that show the implementation of the specified functions and their relationships. In this specification, the boundaries of these functional components are arbitrarily defined for the sake of explanation. Alternative boundaries may be defined to the extent that the specified functions and their relationships are properly implemented.

[0059] The general nature of the embodiments of this disclosure will be apparent from the foregoing description of such specific embodiments to such an extent that others may readily modify and / or adapt the specific embodiments for various applications without undue experimentation, without departing from the general idea of the embodiments of this disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and scope of the equivalents of the disclosed embodiments, based on the teachings and guidance presented herein. The syntax or terminology in this specification is for the purpose of explaining the terms or syntax of this specification as would be interpreted by one of ordinary skill in the art in light of the teachings and guidance presented herein, and is not for the purpose of limitation.

[0060] The breadth and scope of the embodiments of this disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

[0061] Unless otherwise specified or understood differently within the context in which it is used, terms related to conditions, such as in particular "can", "could", "might", or "may", generally are intended to convey that while a particular implementation may include a particular feature, element, and / or operation, other implementations may not include the particular feature, element, and / or operation. Thus, such terms related to conditions generally are not intended to imply that a feature, element, and / or operation is required in any way in one or more implementations, nor is the logic for determining whether these features, elements, and / or operations are included in any particular implementation, or whether these features, elements, and / or operations are to be performed in any particular implementation, necessarily included in one or more implementations regardless of the presence or absence of user input or prompts.

[0062] The specification and drawings disclose examples of systems, devices, apparatuses, and techniques that can manufacture reactor modules within a manufacturing facility and transport them to a manufacturing site where the modules are assembled, thereby significantly reducing the complexity and cost of on-site manufacturing. Further, the reactor system is simplified and further promotes factory manufacturing instead of on-site manufacturing.

[0063] One of ordinary skill in the art will recognize that any process or method disclosed herein can be modified in many ways. The process parameters and arrangements of the steps described and / or illustrated herein are given by way of example only and can be varied as desired. For example, the steps illustrated and / or described herein can be shown or described in a particular order, but these steps need not necessarily be performed in the order illustrated or described.

[0064] The various exemplary methods described and / or illustrated herein can also omit one or more of the steps described or illustrated herein, or can include additional steps in addition to the disclosed steps. Further, the steps of any method disclosed herein can be combined with any one or more steps of any other method disclosed herein.

[0065] Of course, for the purpose of describing the various features of the present disclosure, it is impossible to describe all possible combinations of elements and / or methods. However, those skilled in the art will recognize that additional numerous combinations and permutations of the disclosed features are possible. Accordingly, various modifications can be made to the present disclosure without departing from the scope or spirit of the present disclosure. Further, by considering the specification and the attached drawings, and by practicing the disclosed embodiments presented herein, other embodiments of the present disclosure may become apparent. The examples presented in the specification and the attached drawings should be considered in all respects to be illustrative and not restrictive. Specific terms are used in the specification, but they are used only in a general and descriptive sense and not for the purpose of limitation.

[0066] Unless otherwise specified, the terms "connected" and "coupled" (and their derivatives) used in the specification should be construed to allow both direct and indirect (i.e., through other elements or components) connections. Further, the term "a" or "an" used in the specification should be construed to mean "at least one of". Finally, for ease of use, the terms "comprising" and "having" (and their derivatives) used in the specification are interchangeable with the word "including" and have the same meaning.

[0067] From the above and from the accompanying drawings, specific implementations are described herein for illustrative purposes, but it will be understood that various modifications can be made without departing from the spirit and scope of the appended claims and the requirements recited in the claims. Additionally, while specific aspects are presented below in specific claim forms, the inventors contemplate various aspects in any available claim form. For example, while some aspects may currently be described as being implemented only in a specific configuration, other aspects may similarly be so implemented. Various modifications and changes can be made that will be apparent to those skilled in the art who obtain the benefits of this disclosure. All such modifications and changes are intended to be included. Accordingly, the above description should be considered in an illustrative rather than a limiting sense.

Brief Description of the Drawings

[0068]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Claims

1. fabricating a reactor vessel at a manufacturing facility; manufacturing a core barrel in the manufacturing facility; manufacturing a reactor core in the manufacturing facility; manufacturing a control element drive system at the manufacturing facility; assembling, at the manufacturing facility, the control element drive system and the core within the core barrel to form a core module; transporting the core module to a construction site; manufacturing, in the manufacturing facility, a reactor vessel head to be attached to an upper end of the reactor vessel; assembling the reactor vessel head with a control element support structure, the control element support structure being configured to mount to the reactor vessel head and to hold one or more control elements; 1. A method of constructing a nuclear reactor comprising the step of attaching the core barrel to the control element support structure, the core barrel being suspended from the control element support structure, the control element support structure being configured to support a weight of each of the one or more control elements, the core barrel, and the core.

2. 2. The method of constructing a nuclear reactor as recited in claim 1, further comprising the step of transporting said reactor vessel to said construction site.

3. 3. The method of constructing a nuclear reactor as recited in claim 2, further comprising the step of installing said reactor vessel in a reactor building.

4. 4. The method of constructing a nuclear reactor as recited in claim 3, further comprising the step of placing said core module within said reactor vessel.

5. 5. The method of constructing a nuclear reactor as recited in claim 4, further comprising the step of coupling said core module to a first portion of a reactor vessel head.

6. 6. The method of constructing a nuclear reactor as recited in claim 5, further comprising coupling said control element drive system to said first portion of said reactor vessel head.

7. 10. The method of constructing a nuclear reactor of claim 1, wherein fabricating the core barrel comprises forming the core barrel into a cylindrical shape.

8. 7. The method of constructing a nuclear reactor as recited in claim 6, wherein the core barrel receives and supports the weight of the core.

9. 10. The method of constructing a nuclear reactor as recited in claim 1, further comprising constructing a lower core support structure connecting said core barrel to a lower portion of said reactor vessel and limiting relative movement between said core barrel and said reactor vessel.

10. 2. The method of constructing a nuclear reactor as defined in claim 1, wherein said control element drive system is inserted into and supported by said core barrel.

11. a reactor vessel head having a first opening; a control element support structure attached to the reactor vessel head at the first opening, the control element support structure supporting a plurality of control elements; a support cylinder having an upper portion and a lower portion and supporting the reactor core therein; the upper portion is attached to the control element support structure, and the support cylinder is supported by the control element support structure; A nuclear reactor core support system, wherein the support cylinder is suspended from the control element support structure within a reactor vessel having a plurality of control elements, the control element support structure supporting the weight of each of the plurality of control elements, the support cylinder, and the core.

12. 12. The nuclear reactor core support system of claim 11, wherein said support cylinder is shipped preassembled with said core therein.

13. 12. The nuclear reactor core support system of claim 11, further comprising a control element support system for inserting and extracting a plurality of control elements from the reactor core, said control element support system being attached to said support cylinder.

14. 12. The nuclear reactor core support system of claim 11, wherein the core is located within a support cylinder, and the entire weight of said core is supported by said reactor vessel head through said support cylinder.

15. 12. The nuclear reactor core support system of claim 11, further comprising a fuel element handling system for loading and unloading fuel elements from the reactor core, the fuel element handling system being mounted to a support cylinder.

16. 12. The nuclear reactor core support system of claim 11, further comprising a lower core support structure coupled to the lower portion of the support cylinder, the lower core support structure engaging a lower portion of the reactor vessel to limit lateral movement of the support cylinder relative to the reactor vessel.

17. 17. The nuclear reactor core support system of claim 16, wherein the lower core support structure comprises a conical support portion and a cylindrical support portion joined by a transition portion.

18. 20. The nuclear reactor core support system of claim 17, wherein said lower core support structure further comprises one or more vertical ribs that mate with said conical support portion to provide additional rigidity and stability.

19. 12. The nuclear reactor core support system of claim 11, wherein said support cylinder is configured for radial and axial thermal expansion while being restricted from lateral movement to maintain alignment with said plurality of control elements.

20. 12. The nuclear reactor core support system of claim 11, wherein said support cylinder interfaces with said control element support structure such that seismic forces acting on said reactor vessel head cause substantially the same movement of said support cylinder and said plurality of control elements to maintain alignment of said core with said plurality of control elements.

Images