Apparatus, system, and method for enhancing implementation of nuclear instrumentation control circuits and control systems

Abstract

Disclosed herein is a nuclear instrumentation and control system. The nuclear instrumentation and control system may include a housing and a plurality of selectively removable completed board assemblies installed within the housing and configured to be electrically connected to a nuclear reactor of the instrumentation and control system. At least one of the selectively removable completed board assemblies includes input / output circuitry. The nuclear instrumentation and control system may further include a daughter card including control circuitry, the daughter card configured to be selectively connected to at least one selectively removable base board of the plurality of selectively removable base boards via a mechanical connector and an electrical connector.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority under 35 U.S.C. § 120 of U.S. patent application Ser. No. 17 / 813,295, filed July 18, 2023, entitled "DEVICES, SYSTEMS, AND METHODS FOR ENHANCING THE IMPLEMENTATION OF CONTROL CIRCUITS FOR NUCLEAR INSTRUMENTATION AND CONTROL SYSTEMS," the contents of which are incorporated herein by reference in their entirety.

[0002] The present disclosure relates generally to nuclear power generation, and more particularly to improved control circuitry for increased robustness and versatility when applied to nuclear instrumentation and control systems of nuclear reactors. Summary of the Invention [Means for solving the problem]

[0003] The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed herein and is not intended to be a complete description, with a full understanding of the various embodiments being possible when taken together with the entire specification, claims, and abstract.

[0004] In various aspects, a nuclear instrumentation and control system is disclosed. The nuclear instrumentation and control system can include a housing and a plurality of selectively removable base boards disposed within the housing and configured to be electrically connected to a nuclear reactor of the instrumentation and control system. At least one of the selectively removable base boards includes input / output circuitry. The nuclear instrumentation and control system further includes a daughter board including control circuitry, the daughter board configured to be selectively connected to at least one of the plurality of selectively removable base boards via a mechanical connector and an electrical connector.

[0005] In various aspects, a plurality of selectively removable base substrates configured for use in a nuclear instrumentation and control system are disclosed, wherein at least one of the selectively removable base substrates can include a daughter board including input / output circuitry and control circuitry, the daughter board configured to be selectively connected to at least one of the plurality of selectively removable base substrates via a mechanical connector and an electrical connector.

[0006] In various aspects, a method for reducing the risk of common cause failures in a nuclear instrumentation and control system is disclosed. The method can include electrically connecting a first daughter board having a first control circuit to a first input / output circuit of a first selectively removable base board of the instrumentation and control system, attaching the first selectively removable base board to the instrumentation and control system, electrically connecting a second daughter board having a second control circuit to a second input / output circuit of a second selectively removable base board of the instrumentation and control system, the first control circuit being different from the second control circuit, attaching the second selectively removable base board to the instrumentation and control system, and monitoring a physical parameter of a nuclear reactor plant process via the instrumentation and control system.

[0007] These and other objects, features, and characteristics of the present disclosure, as well as the method of operation and function of the associated elements of construction, and combination of parts and economy of production, will become more apparent from a consideration of the following description and appended claims, taken in conjunction with the accompanying drawings, which form a part hereof and in which like reference numerals indicate corresponding parts. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

[0008] The various features of the embodiments described herein are set forth with particularity in the appended claims. However, the various embodiments, together with their advantages, both as to organization and method of operation, may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1 is a front view of an instrumentation and control system configured for use with a nuclear reactor, in accordance with at least one non-limiting embodiment of the present disclosure.

[0010] [Figure 1B] FIG. 1B is a perspective view of the nuclear instrumentation and control system of FIG. 1A in accordance with at least one non-limiting embodiment of the present disclosure.

[0011] [Figure 2] FIG. 1C illustrates an exemplary base substrate configured for use with the nuclear instrumentation and control system of FIGS. 1A and 1B, in accordance with at least one non-limiting embodiment of the present disclosure.

[0012] [Figure 3] 3 shows a block diagram of a plan view of the base substrate of FIG. 2 in accordance with at least one non-limiting embodiment of the present disclosure.

[0013] [Figure 4]3 shows a block diagram of a top view of a daughter card configured for use with the base substrate of FIG. 2 in accordance with at least one non-limiting embodiment of the present disclosure.

[0014] [Figure 5] FIG. 1 illustrates a method for enhancing implementation of a control circuit for use with a nuclear instrumentation and control system, in accordance with at least one non-limiting aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Corresponding reference characters indicate corresponding parts throughout the several drawings. The examples set forth herein illustrate, in one form, various aspects of the invention, and such examples are not to be construed as limiting the scope of the invention in any way.

[0016] Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, production, and use of the embodiments as described in this disclosure and illustrated in the accompanying drawings. Well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described herein. The reader will understand that the embodiments described and illustrated herein are non-limiting examples, and thus, the specific structural and functional details disclosed herein may be representative and exemplary. Variations and modifications thereof may be made without departing from the scope of the claims. Furthermore, it should be understood that terms such as "front," "rear," "left," "right," "upper," and "lower" are terms of convenience and are not to be construed as limiting terms.

[0017] In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings. It should also be understood that in the following description, terms such as "front," "rear," "left," "right," "upper," and "lower" are used for convenience only and are not to be construed as limiting terms.

[0018] As used in any aspect of the present specification, the term "control circuitry" may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, a processing unit, a processor, a microcontroller, a microcontroller unit, a controller, a digital signal processor ("DSP"), a programmable logic device ("PLD"), a programmable logic array ("PLA"), or a field programmable gate array ("FPGA"), state machine circuitry, firmware that stores instructions executed by the programmable circuitry, and any combination thereof. Control circuitry may collectively or individually be used in, for example, an integrated circuit ("IC"), an application specific integrated circuit ("ASIC"), a system on a chip ("SoC"), a desktop computer, It may also be embodied as circuitry forming part of a larger system, such as a laptop computer, a tablet computer, a server, a smartphone, or the like. Accordingly, a "control circuit," as used herein, includes, but is not limited to, an electrical circuit having at least one discrete electrical circuit, an electrical circuit having at least one integrated circuit, an electrical circuit having at least one application-specific integrated circuit, an electrical circuit forming a general-purpose computing device configured by a computer program (e.g., a general-purpose computer configured by a computer program that at least partially executes the processes and / or apparatus described herein, or a microprocessor configured by a computer program that at least partially executes the processes and / or apparatus described herein), an electrical circuit forming a memory device (e.g., in the form of random access memory), and / or an electrical circuit forming a communications device (e.g., a modem, a communications switch, or an optoelectronic device). Those skilled in the art will recognize that the subject matter described herein can be implemented in analog or digital fashion, or some combination thereof. Furthermore, it should be understood that, as referred to herein, any particular type of control circuit can be effectively interchanged with any of the control circuits described above.

[0019] As used in any aspect herein, the term "logic" may refer to an app, software, firmware, and / or circuitry configured to perform any of the operations described above. Software may be embodied as a software package, code, instructions, instruction sets, and / or data recorded on a non-transitory computer-readable storage medium. Firmware may be embodied as code, instructions, instruction sets, and / or data hard-coded (e.g., non-volatile) in a memory device.

[0020] As used in any aspect of this specification, the terms "component," "system," "module," and the like may refer to a computer-related entity that is either hardware, a combination of hardware and software, software, or software in execution.

[0021] As used in any aspect of this specification, an "algorithm" refers to a self-consistent sequence of steps leading to a desired result, and the "steps" refer to manipulations on physical quantities and / or logical states which may, but need not, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. These signals are commonly referred to as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and / or states.

[0022] Before describing various aspects of the articulated manipulator in detail, it should be noted that the illustrative embodiments are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative embodiments may be implemented or incorporated in other aspects, variations, and modifications, and may be practiced or carried out in various ways. Moreover, unless otherwise indicated, the terms and phrases employed herein have been chosen for the convenience of the reader for the purpose of describing the illustrative embodiments, and not for purposes of limitation thereof. It will also be understood that one or more of the aspects, aspect expressions, and / or examples described below can be combined with any one or more of the other aspects, aspect expressions, and / or examples described below.

[0023] As nuclear reactors become increasingly complex, nuclear control systems also become more complex, often requiring a degree of customization, provided through specially programmed processors and / or control circuits such as custom field-programmable gate arrays ("FPGAs"). However, designing and manufacturing custom FPGAs is costly. The critical nature of nuclear control system functionality further increases the difficulty and expense associated with custom FPGA design. Clearly, a failure of a nuclear reactor's nuclear instrumentation and control system could have catastrophic consequences. Consequently, traditional FPGA design relies on human diversity in development, meaning two separate design teams are required to create a specific platform implementation. For example, two teams may be required to manufacture the platform's general-purpose "slave" boards (e.g., input boards, output boards, communications boards), application-specific integrated circuits ("ASICs"), and / or FPGAs. While potentially expensive, redundant, and inefficient use of resources, human diversity can successfully mitigate the risk of "common cause" failures, thereby increasing the reliability of nuclear instrumentation and control systems designed in this manner.

[0024] One non-limiting aspect of a nuclear instrumentation and control system for nuclear reactors is the Advanced Logic System® ("ALS") platform manufactured by Westinghouse Electric. For example, ALS is a hardware-based architecture that incorporates self-testing capabilities to detect and mitigate the effects of failures both within and outside the system. The ALS platform design uses custom-built FPGAs containing programmable logic components and programmable interconnects that can be combined into more complex combinatorial functions, such as decoders and mathematical functions. In other words, FPGAs can be utilized to perform the necessary functions of input / output ("I / O") boards for plant processes, and / or application-specific boards (e.g., core logic boards ("CLBs")) configured for specific applications of the ALS, as well as general-purpose boards (e.g., slave boards) for the ALS. Traditional nuclear instrumentation and control systems, such as the first version of the ALS, involved bonding FPGAs to a base board, with the I / O circuitry located on the same base board. This made each board inflexible and, if an FPGA failed, very costly to replace. Therefore, conventional instrumentation and control systems for nuclear applications utilize the aforementioned (inefficient) human diversity development process to mitigate the risk of FPGA failure. Therefore, there is a need for an apparatus, system, and method for hardening the implementation of control circuits in nuclear instrumentation and control systems.

[0025] 1A, there is depicted a front view of an instrumentation and control system 100 configured for use with a nuclear reactor, in accordance with at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 1A, the instrumentation and control system 100 includes one or more substrates 102. a-c , which are configured to be inserted into the housing 104 and mechanically and electrically connected to the housing 104. For example, one or more substrates 102 a-c The core logic board 102 a , input / output board 102 b , and / or the communication board 102 cFor example, the core logic board 102 a can be configured to function through a primary decision making circuit, which can include the functional logic of the instrumentation control system 100 with a data link interface to an external system.

[0026] Input / output board 102 b The communications board 102 may be configured to convert certain types of field signals to digital signals and perform certain filtering of the inputs, among other signaling and processing functions. c For example, the core logic board 102 of FIG. 1A may provide a bidirectional data link interface with other controllers. a , input / output board 102 b , and the communication board 102 c It should be understood that the boards 102 are presented for illustrative purposes only. Accordingly, any number and / or type of boards may be implemented via the instrumentation control system 100 of FIG. 1 depending on user preference and / or intended use. a-c can cooperate to provide a universal, reliable control system platform that enables diagnostics, testability, and modularity for the instrumentation and control system 100 of Figure 1A, which is intended for safety-critical controls capable of Class 1E certification from the U.S. Nuclear Regulatory Commission for use in systems such as, for example, Reactor Protection System ("RPS") and / or Engineered Safety Function Actuation System ("ESFAS") applications. However, it should be understood that the instrumentation and control system 100 of Figure 1A can have any number of nuclear applications and is not limited to those described herein.

[0027] 1B, a perspective view of the nuclear instrumentation and control system 100 of FIG. 1A is depicted, in accordance with at least one non-limiting embodiment of the present disclosure. Specifically, FIG. 1B illustrates a slave board 102 a-c1B shows how the slave board 102 can be selectively inserted into, and in the case of FIG. 1B removed from, the housing 104 of the instrumentation control system 100. Thus, the instrumentation control system 100 includes a slave board 102 a-c Each slave board 102 can be configured as a base device. a-c can be selectively mechanically connected to the housing 104 and then removed from the housing 104. Once each slave board is mechanically connected within the housing, the slave boards 102 a-c The necessary electrical connections (not shown) can be established so that each slave board 102 is electrically connected to a system interface (not shown) within the housing 104. a-c are able to cooperate to accomplish the programmed functions of the instrumentation control system 100.

[0028] For example, various slave boards 102 a-c 1A can be configured to function as a reactor protection system ("RPS"), a reactor trip system ("RTS"), an engineered safety function activation system ("ESFAS"), an emergency power distribution average and diesel load sequencer ("DLS"), a main steam and feedwater isolation system ("MSFIS"), a thermocouple core cooling monitor ("TCCM"), a post-accident monitoring system ("PAMS"), and / or a safety rating control system, among other nuclear-specific functions. The various boards 102 of the instrumentation and control system 100 a-c It will be appreciated that the components may be interchangeable to achieve desired functionality depending on user preference and / or intended use. In other words, the instrumentation and control system 100 of Figures 1A and 1B can be modularly configured to provide input / output (I / O) and / or application-specific functionality to support various plant processes.

[0029] 2, an exemplary slave board 202 configured for use with the nuclear instrumentation and control system 100 of FIGS. 1A and 1B is depicted, in accordance with at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 2, the slave board 202 may include a base board 204 and a daughter card 206 selectively mechanically connected to the base board 204. The daughter card 206 may include a circuit board including any circuitry and components mounted thereon, which may be safely disconnected from the base board 204 via one or more electrical connectors 210 and mechanical connectors 208. For example, the one or more electrical connectors may include, but are not limited to, power and / or I / O connectors, or any equivalent ports, such as an Integrated Drive Electronic ("IDE") connector, a Small Computer Systems Interface ("SCSI") connector, a Peripheral Component Interconnect ("PCI") connector, a PCI Express ("PCIe") connector, a Universal Serial Bus ("USB") connector, a VITA 57.1 FMC (FPGA Mezzanine Card), a Serial Peripheral Interface ("SPI") connector, and / or a Data Bus ("DB") connector. According to some non-limiting embodiments, the present disclosure contemplates electrical connector 210 and mechanical connector 208 that are seismically hardened for application in nuclear environments. For example, electrical connector 210 can include a higher pin count (e.g., 200-300, 400, 600 pins) and / or mechanical connector 208 can include jackscrews. In other words, the electrical connection of the daughter card to the base substrate can be designed to withstand earthquakes. To ensure earthquake resistance, the electrical connection of the daughter card to the base substrate is designed to have a high decoupling force. Jack screws can be used to securely mechanically connect the daughter card to the base substrate while simultaneously providing the decoupling force necessary to separate the daughter card and the base substrate without damaging either circuit board.4, the daughter cards 206 of FIG. 2 may include control circuitry and related circuitry, which would conventionally be located on the base substrate 204. Conversely, the base substrate 204 may include I / O circuitry, which would conventionally be located on the daughter cards 206.

[0030] 3, there is depicted a block diagram of a top view of the base substrate 204 of the completed substrate assembly 202 of FIG. 2, in accordance with at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 3, the base substrate 204 includes electrical connectors 304 configured to establish electrical communication between the base substrate 204 and the daughter cards 304. a , 304 b 2 and 4. For example, the footprint 302 for the daughter card 206 (FIGS. 2 and 4) may include an electrical connector 304. a , 304 b may include any of the power or I / O connectors described above, or other connectors configured to transfer power and / or data to and from daughter card 206 (FIGS. 2 and 4) when connected.

[0031] Still referring to FIG. 3, the base board 204 may include a front panel interface 306, which may include one or more field connectors 307. a , 307 b , and one or more lights (e.g., light emitting diodes, incandescent bulbs, etc.) to indicate proper installation within housing 104 (FIGS. 1A and 1B), one or more channel circuits 308, a power supply circuit 310, and / or one or more bus interface circuits 312 a-c Of course, the circuitry illustrated in Figure 3 is merely exemplary and is not intended to be limiting. Thus, it will be appreciated that the base substrate 204 of Figure 3 may alternatively be configured to include any number of other circuits according to user preference and / or intended use.

[0032] 4, there is depicted a block diagram of a top view of a daughter card 206 configured for use with the completed substrate assembly 202 of FIG. 2, in accordance with at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 4, the daughter card 206 may include control circuitry 402. For example, the control circuitry 402 may include an FPGA. However, according to other non-limiting embodiments, the control circuitry 402 may include an ASIC, a processor, a microprocessor, or any other logic-based and / or instruction-executing component as disclosed herein.

[0033] 4, the control circuitry 402 may be mounted on logic and configuration circuitry 406 of the daughter card 206. The daughter card 206 may be mounted on the electrical connector 304 of the base substrate 204, as depicted in FIG. a , 304 b Electrical connector 404 corresponding to a , 404 b As mentioned above, the electrical connector 404 a , 404 b , 304 a , 304 b (FIG. 3) can be specifically configured to transfer power and / or I / O signals between the base substrate 204 (FIG. 3) and the daughterboards 206 when properly attached to the base substrate 204. According to a non-limiting embodiment of FIG. 3, the daughtercards 206 may include one or more power supplies 406 configured to provide power to the circuitry of the daughtercards 206 and / or the base substrate 204, as needed. a , 406 b It may further include:

[0034] Still referring to FIG. 4 , the fact that the control circuitry 402 is mounted on the daughter card 206 rather than the base board 204 ( FIGS. 2 and 3 ) provides the nuclear instrumentation and control system 100 ( FIGS. 1A and 1B ) with a degree of modular flexibility. In conventional nuclear instrumentation and control systems, the control circuitry 402 and associated circuitry, if a daughter card is used, are typically mounted on the base board 204, with associated I / O circuitry mounted on the daughter card 206. For example, the control circuitry may include highly integrated circuits that control processing and / or data transfer functions. In other words, because the control circuitry 402, such as an FPGA, is permanently fixed to the base board, it can be extremely expensive and difficult to remove and replace. Therefore, conventional nuclear instrumentation and control systems prioritize affordability and efficiency by including the control circuitry on the base board, where it can interface with many different boards and subsystems in the system. However, such benefits are achieved at the expense of a high risk of a single point of failure. If the control circuitry fails, the entire base board must be scrapped or, even in the best-case scenario, reworked. This risk obviously increases as control circuitry becomes obsolete.

[0035] In contrast, the daughter card 206 of Figure 4 includes control circuitry 402 and thus provides an interchangeable "personality" module for the functional logic on the base board 206 (Figure 4). In this regard, the various mechanical connectors 208 (Figure 2) and electrical connectors 210 (Figure 2), 304 a , 304 b (Fig. 3), 404 a , 404 bThe selective engagement of the daughter card 206 of FIG. 4 to the base substrate 204 of FIG. 3 via the NI 8024 / 8024 interface enhances the design, qualification, and testing of new control circuits for the nuclear instrumentation and control system 100 (FIGS. 1A and 1B) by improving versatility, flexibility, and robustness. For example, if the control circuit 402 fails or requires replacement, the daughter card 206 can be easily repaired and / or replaced without requiring extensive rework of the base substrate 204 (FIGS. 2 and 3). In other words, the daughter card 206 and base substrate 204 (FIGS. 2 and 3) of the present disclosure enable robustness by eliminating the risk inherent in single-point control circuit failure. This promotes hardware diversity, which can reduce, if not eliminate, the aforementioned costs and inefficiencies associated with the personnel diversity approach to risk mitigation required in conventional designs. For example, the design of the daughter card 206 of FIG. 4 allows control circuits from different manufacturers to be utilized throughout the system 100 (FIG. 1), which creates a stronger risk mitigation situation than most personnel diversity approaches. Specifically, the use of daughter card 206 of FIG. 4 can reduce the independent verification and validation efforts required to certify two different control circuit designs for use in a nuclear system.

[0036] Referring now to FIG. 5 , a method 500 for reducing the risk of common cause failures in a nuclear instrumentation and control system is depicted, according to at least one non-limiting embodiment of the present disclosure. According to FIG. 5 , the method 500 may include electrically connecting 502 a first daughter card comprising a first control circuit to a first selectively removable base board of the instrumentation and control system. Next, the method 500 calls for attaching 504 the first selectively removable completed board assembly to the instrumentation and control system. A second daughter card comprising a second control circuit may similarly be electrically connected 506 to a second selectively removable completed board assembly of the instrumentation and control system. Notably, the first control circuit may be different from the second control circuit, thereby introducing hardware diversity instead of human diversity. Hardware diversity, when applied to a nuclear instrumentation and control system, can sufficiently mitigate the risk of common cause failures. Next, the method 500 calls for attaching 508 a second selectively removable completed board assembly to the instrumentation and control system. Finally, the user can monitor 510 the physical parameters of the reactor plant process (eg, temperature, power, radiation levels, etc.) via the instrumentation and control system.

[0037] Various aspects of the subject matter described herein are set forth in the following numbered sections.

[0038] (Item 1) A nuclear instrumentation and control system comprising: a housing; a plurality of selectively removable completed base board assemblies installed within the housing and configured to be electrically connected to a nuclear plant process of the instrumentation and control system, at least one of the selectively removable completed base board assemblies comprising a base board having input / output circuitry; and a daughter card comprising control circuitry, the daughter card configured to be selectively connected to at least one selectively removable base board of the plurality of selectively removable base boards via a mechanical connector and an electrical connector.

[0039] (Item 2) The nuclear instrumentation control system described in item 1, wherein the control circuit comprises at least one of a field programmable gate array, an application specific integrated circuit, and a microprocessor.

[0040] (Item 3) A nuclear instrumentation control system according to either item 1 or 2, wherein the mechanical connectors and electrical connectors are earthquake-resistant.

[0041] (Item 4) A nuclear instrumentation control system according to any one of items 1 to 3, wherein the mechanical connector includes a jack screw.

[0042] (Item 5) A nuclear instrumentation control system according to any one of items 1 to 4, wherein the electrical connector has more than 200 pins and less than 600 pins.

[0043] (Item 6) A nuclear instrumentation control system according to any one of Items 1 to 5, wherein the electrical connector has 400 pins.

[0044] (Item 7) A nuclear instrumentation control system according to any one of Items 1 to 6, wherein the daughter board further comprises a core logic circuit.

[0045] (Item 8) A nuclear instrumentation control system described in any of Items 1 to 7, wherein the plurality of selectively removable completed board assemblies comprises at least one of an input board, an output board, and a communication board, or a combination thereof.

[0046] (Item 9) A nuclear instrumentation control system described in any of Items 1 to 8, further comprising a second daughter card having a second control circuit, the second daughter card being configured to be selectively connected to at least one selectively removable base substrate of a plurality of selectively removable completed base assemblies, and the second control circuit being different from the control circuit.

[0047] (Item 10) A nuclear instrumentation control system according to any one of items 1 to 9, wherein the control circuit has a different design from the second control circuit.

[0048] (Item 11) A nuclear instrumentation control system according to any one of items 1 to 10, wherein the control circuit has a different manufacturer or production line from the second control circuit.

[0049] (Item 12) A plurality of selectively removable completed substrate assemblies configured for use in a nuclear instrumentation and control system, at least one of the selectively removable completed substrate assemblies comprising: a base substrate having input / output circuitry; and a daughter card having control circuitry, the daughter card configured to be selectively connected to at least one selectively removable base substrate of the plurality of selectively removable base substrates via a mechanical connector and an electrical connector.

[0050] (Item 13) A plurality of selectively removable base substrates as described in Item 12, wherein the control circuit comprises at least one of a field programmable gate array, an application specific integrated circuit, and a microprocessor.

[0051] (Item 14) A plurality of selectively removable base substrates according to either item 12 or item 13, wherein the mechanical connectors and electrical connectors are vibration resistant.

[0052] (Item 15) A plurality of selectively removable base substrates according to any one of items 12 to 14, wherein the mechanical connector comprises a jack screw.

[0053] (Item 16) A plurality of selectively removable base substrates according to any one of items 12 to 15, wherein the electrical connector has 400 pins.

[0054] (Item 17) A plurality of selectively removable base substrates described in any of items 12 to 16, wherein a second selectively removable base substrate of the plurality of selectively removable base substrates comprises a second daughter card having a second control circuit, the second daughter card being configured to be selectively connected to the second selectively removable base substrate of the plurality of selectively removable base substrates, and the second control circuit being different from the control circuit.

[0055] (Item 18) A plurality of selectively removable base substrates according to any one of items 12 to 17, wherein the control circuit has a different design from the second control circuit.

[0056] (Item 19) A plurality of selectively removable base substrates according to any one of items 12 to 14, wherein the control circuit has a different manufacturer or manufacturing line from the second control circuit.

[0057] (Item 20) A method for reducing the risk of common cause failures in a nuclear instrumentation and control system, comprising: electrically connecting a first daughter card having a first control circuit to a first input / output circuit of a first selectively removable base board of the instrumentation and control system; attaching the first selectively removable completed board assembly to the instrumentation and control system; electrically connecting a second daughter card having a second control circuit to a second input / output circuit of a second selectively removable base board of the instrumentation and control system, wherein the first control circuit is different from the second control circuit; attaching the second selectively removable completed board assembly to the instrumentation and control system; and monitoring physical parameters of a nuclear reactor plant process via the instrumentation and control system.

[0058] All patents, patent applications, publications, or other disclosure materials mentioned herein are incorporated herein by reference in their entirety, as if each individual reference were expressly incorporated by reference. All references and any materials, or portions thereof, that are incorporated herein by reference are incorporated herein only to the extent that the incorporated materials do not contradict existing definitions, descriptions, or other disclosure materials set forth in this disclosure. Therefore, to the extent necessary, the disclosure set forth herein supersedes any conflicting materials incorporated herein by reference, and the disclosure expressly set forth in this application controls.

[0059] The present invention has been described with reference to various exemplary and illustrative embodiments. It is understood that the embodiments described herein provide illustrative features of various details of the various embodiments of the disclosed invention, and thus, unless otherwise specified, it is understood that, to the extent possible, one or more features, elements, components, ingredients, materials, structures, modules, and / or aspects of the disclosed embodiments can be combined, separated, interchanged, and / or rearranged with or with respect to one or more other features, elements, components, ingredients, materials, structures, modules, and / or aspects of the disclosed embodiments without departing from the scope of the disclosed invention. Accordingly, those skilled in the art will recognize that various substitutions, modifications, or combinations of any of the exemplary embodiments can be made without departing from the scope of the invention. Moreover, those skilled in the art will recognize or be able to ascertain, upon review of this specification, many equivalents to the various embodiments of the invention described herein using no more than routine experimentation. Accordingly, the present invention is not limited by the description of the various embodiments, but rather by the scope of the claims.

[0060] Those skilled in the art will recognize that, generally, the terms used in this specification, and particularly in the appended claims (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "comprising" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.). Those skilled in the art will further understand that if a specific number of introduced claim recitations are intended, such intention will be explicitly set forth in the claim; otherwise, no such intention exists. For example, as an aid to understanding, the appended claims below may use the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to mean that introducing a claim recitation with the indefinite article "a" or "an" limits any particular claim containing a claim recitation so introduced to claims containing only one such recitation, even if that same claim also contains the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should ordinarily be construed to mean "at least one" or "one or more"), and the same applies to definite articles used to introduce claim recitations.

[0061] Furthermore, even when a specific number of recitations in an introduced claim is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., a minimum recitation of "two recitations" without other modifiers typically means at least two recitations, or more than two recitations). Furthermore, when a convention similar to "at least one of A, B, and C, etc." is used, such a configuration is generally intended in the sense that those skilled in the art would understand the convention (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together). When a convention similar to "at least one of A, B, or C, etc." is used, such configuration is generally intended in the sense that one of ordinary skill in the art would understand that convention (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together). As will be further understood by one of ordinary skill in the art, whether in the specification, claims, or drawings, disjunctive words and / or phrases that typically present two or more alternative terms should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms, unless the context dictates otherwise. For example, the phrase "A or B" is typically understood to include the possibilities of "A" or "B" or "A and B."

[0062] With respect to the appended claims, those skilled in the art will understand that the operations recited therein may generally be performed in any order. Also, while the claims are presented in a sequential order, it should be understood that various operations may be performed in orders other than those recited, or may be performed simultaneously. Examples of such alternative orders include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, concurrent, reversed, or other variations, unless the context dictates otherwise. Furthermore, terms such as past tense adjectives, such as "responsive to" and "related to," are generally not intended to exclude such variations, unless the context dictates otherwise.

[0063] It should be noted that references to "one embodiment," "an embodiment," "an example," "one example," etc. mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "in an example," and "in one example" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0064] As used herein, the singular forms "a", "an" and "the" include the plural forms as well, unless the context clearly indicates otherwise.

[0065] Directional terms used herein, such as, but not limited to, top, bottom, left, right, below, over, front, rear, and variations thereof, refer to the orientation of the elements as shown in the accompanying drawings and do not limit the scope of the claims, unless expressly stated otherwise.

[0066] As used in this disclosure, the term "approximately" or "about" refers to an acceptable error for a particular value as determined by one of ordinary skill in the art, unless otherwise specified, which depends in part on how the value is measured or determined. In certain embodiments, the term "approximately" or "about" refers to within 1, 2, 3, or 4 standard deviations. In certain embodiments, the term "approximately" or "about" refers to within 50%, 200%, 105%, 100%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range.

[0067] As used herein, unless otherwise indicated, all numerical parameters are understood to be prefaced and modified in all instances by the term "about," taking into account the inherent variability inherent in the underlying measurement techniques employed to determine the numerical value of such parameters. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter set forth herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0068] Numerical ranges recited herein include all subranges subsumed within the recited range. For example, a range of "1 to 100" includes all subranges between (and including) the recited minimum of 1 and the recited maximum of 100, i.e., having a minimum of 1 or more and a maximum of 100 or less. Also, all ranges recited herein include the recited endpoints. For example, the range "1 to 100" includes the endpoints 1 and 100. Every maximum numerical limitation recited herein is intended to include every subnumerical limitation subsumed therein, and every minimum numerical limitation recited herein is intended to include every upper numerical limitation subsumed therein. Accordingly, applicants reserve the right to amend this specification, including the claims, to expressly recite any subranges subsumed within the expressly recited ranges. All such ranges are inherently described herein.

[0069] Any patent applications, patents, non-patent publications, or other disclosure materials referred to herein and / or set forth in an Application Data Sheet are incorporated herein by reference to the extent that the incorporated material does not contradict this specification. Therefore, to the extent necessary, the disclosure expressly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, purportedly incorporated herein by reference that contradicts any existing definitions, statements, or other disclosure material set forth herein is incorporated only to the extent that no conflict arises between the incorporated material and the existing disclosure material.

[0070] "Comprise" (and any form of comprise, such as "comprises" or "comprising"), "have" (and any form of have, such as "has" or "having"), "include" (and any form of include, such as "includes" or "including"), and "contain" (and any form of contain, such as "contains" or "containing") are open-ended linking verbs. Consequently, a system that "comprises," "has," "includes," or "contains" one or more elements has those one or more elements, but is not limited to possessing only those one or more elements. Similarly, a system, device, or equipment element that "comprises," "has," "includes," or "contains" one or more features has those one or more features, but is not limited to possessing only those one or more features.

Claims

1. A nuclear instrumentation and control system, Housing and a plurality of selectively removable completed board assemblies configured to be installed within a housing and electrically connected to a nuclear plant process of the instrumentation and control system, at least one selectively removable base board comprising input / output circuitry; a daughter card including control circuitry, the daughter card configured to be selectively connected to the at least one selectively removable base substrate of a plurality of selectively removable base substrates via a mechanical connector and an electrical connector; A nuclear instrumentation and control system equipped with:

2. 10. The nuclear instrumentation and control system of claim 1, wherein the control circuit comprises at least one of a field programmable gate array, an application specific integrated circuit, and a microprocessor.

3. The nuclear instrumentation and control system of claim 2 , wherein the mechanical connector and the electrical connector are earthquake-resistant.

4. The nuclear instrumentation and control system of claim 3 , wherein the mechanical connector comprises a jackscrew.

5. 4. The nuclear instrumentation and control system of claim 3, wherein the electrical connector comprises more than 200 pins and less than 600 pins.

6. 6. The nuclear instrumentation and control system of claim 5, wherein the electrical connector comprises 400 pins.

7. The nuclear instrumentation and control system of claim 1 , wherein the daughter board further comprises a functional logic circuit.

8. 10. The nuclear instrumentation and control system of claim 1, wherein the plurality of selectively removable completed board assemblies comprises at least one of a core logic board, an input board, an output board, and a communication board, or a combination thereof.

9. a second daughter card including a second control circuit; the second daughter card is configured to be selectively connected to the at least one selectively removable base substrate of the plurality of selectively removable base substrates; The nuclear power instrumentation and control system according to claim 1 , wherein the second control circuit is different from the control circuit.

10. 10. The nuclear instrumentation and control system of claim 9, wherein the control circuit has a different design than the second control circuit.

11. 10. The nuclear instrumentation and control system of claim 9, wherein the control circuit has a different manufacturer than the second control circuit.

12. A plurality of selectively removable base substrates configured for use in a nuclear instrumentation and control system, comprising: At least one of the selectively removable base substrates comprises: an input / output circuit; a daughter card including control circuitry, the daughter card configured to be selectively connected to the at least one selectively removable base substrate of the plurality of selectively removable base substrates via a mechanical connector and an electrical connector; a plurality of selectively removable base substrates comprising:

13. 13. The plurality of selectively removable base substrates of claim 12, wherein the control circuitry comprises at least one of a field programmable gate array, an application specific integrated circuit, and a microprocessor.

14. The plurality of selectively removable base substrates of claim 13 , wherein the mechanical connectors and the electrical connectors are vibration resistant.

15. The plurality of selectively removable base substrates of claim 14 , wherein the mechanical connectors comprise jack screws.

16. 15. The plurality of selectively removable base substrates of claim 14, wherein the electrical connector comprises 400 pins.

17. a second selectively removable base substrate of the plurality of selectively removable base substrates includes a second daughter card including second control circuitry; the second daughter card is configured to be selectively connected to the second selectively removable base substrate of the plurality of selectively removable base substrates; 13. The plurality of selectively removable base substrates of claim 12, wherein the second control circuit is different from the control circuit.

18. 20. The plurality of selectively removable base substrates of claim 17, wherein the control circuit has a different design than the second control circuit.

19. 20. The plurality of selectively removable base substrates of claim 17, wherein the control circuit has a different manufacturer than the second control circuit.

20. 1. A method for reducing the risk of common cause failures in a nuclear instrumentation and control system, comprising: electrically connecting a first daughter card having first control circuitry to first input / output circuitry of a first selectively removable base board of the instrumentation control system; attaching the first selectively removable base substrate to the instrumentation control system; electrically connecting a second daughter card having second control circuitry to second input / output circuitry of a second selectively removable base board of the instrumentation control system, the first control circuitry being different from the second control circuitry; attaching the second selectively removable base substrate to the instrumentation control system; monitoring physical parameters of a nuclear reactor plant process via said instrumentation and control system; A method comprising:

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