Apparatus, system, and method for improving operation of hydraulic control units of control rod drives for regulating nuclear flux within a reactor core

Abstract

A hydraulic control unit ("HCU") configured to control a control rod drive mechanism ("CRDM") configured to control nuclear flux produced by a nuclear reactor is disclosed. The HCU may include a plurality of valves configured to dampen fluid pressure within the CRDM, thereby extending and withdrawing control rods of the CRDM from a reactor vessel of the nuclear reactor, and a control circuit, the control circuit including a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves, a controller electrically connected to the plurality of relay interfaces, and a communication circuit communicatively connected to a header controller, the communication circuit configured to send and receive signals between the controller and the header controller.

Description

[Technical Field]

[0001] The present disclosure relates generally to nuclear power generation, and more particularly to an improved hydraulic control unit for a control rod drive mechanism configured to regulate flux activity within a boiling water nuclear reactor core. Summary of the Invention [Problem to be solved by the invention]

[0002] The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed herein, but is not intended to be a complete description. A complete understanding of the various embodiments can be gained by taking the entire specification, claims, and abstract as a whole. [Means for solving the problem]

[0003] In various aspects, a hydraulic control unit ("HCU") configured to control a control rod drive mechanism ("CRDM") configured to control nuclear flux produced by a nuclear reactor is disclosed, the HCU comprising: a plurality of valves configured to dampen fluid pressure within the CRDM, where damping the fluid pressure extends and retracts control rods of the CRDM into and from a reactor vessel of the nuclear reactor; a control circuit; the control circuit comprising: a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves; a controller electrically connected to the plurality of relay interfaces; and a communication circuit communicatively connected to a header controller, the communication circuit configured to send and receive signals between the controller and the header controller.

[0004] In various aspects, a system configured to control a plurality of control rod drive mechanisms (“CRDMs”) configured to control nuclear flux produced by a nuclear reactor is disclosed. The system may include a header controller and a plurality of hydraulic control units (“HCUs”), each HCU of the plurality of HCUs comprising a plurality of valves configured to attenuate fluid pressure within a CRDM of the plurality of CRDMs, whereby attenuating the fluid pressure causes control rods of the CRDMs to be inserted into and removed from a reactor vessel of the nuclear reactor; a control circuit, the control circuit comprising a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves; a controller electrically connected to the plurality of relay interfaces; and a communication circuit communicatively connected to the header controller, the communication circuit configured to send and receive signals between the controller and the header controller.

[0005] In various aspects, a method of controlling nuclear flux produced by a nuclear reactor is disclosed. The method may include receiving, by a control circuit of a hydraulic control unit ("HCU"), a signal from a control rod drive control system ("RDCS") module, generating, by the control circuit of the HCU, an operation sequence based on the received signal, damping, by the control circuit of the HCU, fluid pressure in a control rod drive mechanism ("CRDM") using a plurality of valves such that the fluid pressure causes control rods of the CRDM to perform the generated operation sequence, detecting, by the control circuit of the HCU, a current associated with each valve of the plurality of valves of the HCU, detecting, by the control circuit of the HCU, a voltage associated with each valve of the plurality of valves of the HCU, determining, by the control circuit of the HCU, a parameter associated with each valve of the plurality of valves of the HCU based on the detected voltage and the detected current, and determining, by the control circuit of the HCU, a state of the operation sequence based on the determined parameter.

[0006] These and other objects, features and characteristics of the present invention, as well as the method of operation and function of the associated elements of construction, and combination of parts and economies of manufacture, will become more apparent from a study of the following description and appended claims, taken in conjunction with the accompanying drawings, it being expressly understood, however, that the drawings are for illustrative purposes only and are not intended to define the limits of the invention. [Brief explanation of the drawings]

[0007] The various features of the embodiments described herein are set forth with particularity in the appended claims. However, the various embodiments, both as to organization and method of operation, together with their advantages, will be best understood by considering the following description in conjunction with the accompanying drawings, in which:

[0008] [Figure 1] FIG. 1 illustrates a cross-sectional view of a control rod drive mechanism (“CRDM”) configured to enhance operation using a hydraulic control unit (“HCU”), in accordance with at least one non-limiting embodiment of the present disclosure.

[0009] [Figure 2] FIG. 2 illustrates an isometric view of the HCU of the CRDM of FIG. 1 in accordance with at least one non-limiting embodiment of the present disclosure.

[0010] [Figure 3] 3A and 3B (collectively "FIG. 3") illustrate a schematic circuit diagram of a control circuit of the HCU of FIG. 2, according to at least one non-limiting embodiment of the present disclosure.

[0011] [Figure 4] FIG. 4 illustrates a chart illustrating the improved operation of the HCU enabled by the control circuit of FIG. 3 in accordance with at least one non-limiting aspect of the present disclosure.

[0012] [Figure 5]FIG. 5 shows another chart illustrating the improved operation of the HCU enabled by the control circuit of FIG. 3 in accordance with at least one non-limiting aspect of the present disclosure.

[0013] [Figure 6] 6A and 6B (collectively "FIG. 6") illustrate a schematic circuit diagram of a controller of a system configured to interact with multiple HCUs, in accordance with at least one non-limiting aspect of the present disclosure.

[0014] [Figure 7] FIG. 7 illustrates a method for improving the operation of an HCU in accordance with at least one non-limiting aspect of the present disclosure.

[0015] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set forth herein illustrate various aspects of the invention in one form or another, and such exemplifications should not be construed as limiting the scope of the invention in any way. DETAILED DESCRIPTION OF THE INVENTION

[0016] Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments described in this disclosure and illustrated in the accompanying drawings. Well-known operations, parts, and elements are not 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 therefore, the specific structural and functional details disclosed herein are to be understood as being representative and illustrative. Variations and modifications 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 words of convenience and are not to be construed as limiting terms.

[0017] In the following description, reference characters indicate like or corresponding parts in the several views. Also, in the following description, it should be understood that 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] The term "control circuitry" as used in any aspect of the present specification may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more discrete 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"), a state machine circuit, firmware that stores instructions executed by the programmable circuit, and any combination thereof. Control circuitry may be embodied collectively or individually as circuitry that forms part of a larger system, such as, for example, an integrated circuit ("IC"), an application specific integrated circuit ("ASIC"), a system on a chip ("SoC"), a desktop computer, a laptop computer, a tablet computer, a server, a smartphone, etc. Accordingly, as used herein, "control circuitry" may refer to a circuit having at least one discrete electrical circuit. These include, but are not limited to, electrical circuits comprising a plurality of integrated circuits, electrical circuits having at least one integrated circuit, electrical circuits having at least one application-specific integrated circuit, electrical circuits 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 devices described herein, or a microprocessor configured by a computer program that at least partially executes the processes and / or devices described herein), electrical circuits forming a memory device (e.g., a form of random access memory), and / or electrical circuits forming a communications device (e.g., a modem, a communications switch, or an optoelectronic appliance). Those skilled in the art will recognize that the subject matter described herein may be implemented in analog or digital fashion, or in some combination thereof. Furthermore, as referred to herein, it should be understood that any particular type of control circuitry may be effectively substituted for any of the control circuits described above.

[0019] The term "logic" as used in any aspect herein 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 or instruction sets, and / or data hard-coded (e.g., non-volatilely) into a memory device.

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

[0021] An "algorithm," as used in any aspect herein, refers to a self-consistent sequence of steps leading to a desired result, and the "steps" refer to manipulations of 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 examples are not limited in application or use to the details of construction and arrangement of parts set forth in the accompanying drawings and description. The illustrative examples may be embodied in or incorporated with other aspects, variations, and modifications, and may be practiced or performed in various ways. Furthermore, unless otherwise noted, the words and phrases used herein have been chosen for the convenience of the reader and for the purpose of describing the illustrative examples, and are not intended to be limiting. It will also be understood that one or more of the aspects, aspect expressions, and / or examples described below may be combined with any one or more of the other aspects, aspect expressions, and / or examples described below.

[0023] Generally, in a nuclear fission reactor, the primary quantity measured to control the nuclear reaction is neutron flux. Therefore, regulating the neutron flux within the reactor is essential for safe and efficient reactor operation. This can be accomplished using a control rod drive mechanism ("CRDM"). The CRDM may include multiple control rods containing neutron absorbers designed to absorb neutrons, thereby regulating the neutron flux within the reactor core. Each control rod in the CRDM may be driven by a hydraulic control unit ("HCU"), which contains the valves and hydraulic system connections necessary to drive each control rod in the CRDM into and out of the reactor. Selectively inserting and removing one or more control rods allows for appropriate flux adjustments depending on the situation. For example, each HCU may include up to four directional control valves ("DCVs"), which operate in a predetermined sequence to control hydraulic forces so that control rods are selectively inserted and removed from the reactor under normal operating conditions. Alternatively, each HCU may include valves and accumulators configured to rapidly insert control rods to transition the reactor to a safe state in the event of a rapid emergency shutdown, such as a safety control rod axisman ("SCRAM") situation. Such SCRAM operations are performed independently of normal use.

[0024] Control of the DCV is performed on a per-control-rod basis. For example, when a control rod is not moving, it is held in place by a collet piston that engages a notched indexing rod. However, when movement is required, a DCV control sequence may remove the locking pressure of the collet piston for any particular control rod. Furthermore, control of the DCV and monitoring of local parameters is typically performed by a local control circuit communicatively connected to the HCU. This control circuit responds to operational commands from the overall control rod drive control system, generated from operator actions, and receives monitored parameters for display via the control system. However, in conventional systems, the control circuit is connected to hundreds of control rod HCUs, resulting in a single point of control and failure. In other words, conventional HCU control circuits can only provide coarse control of the CRDM because they must properly send control signals to each HCU before each control rod can be properly actuated. Furthermore, if a conventional control circuit malfunctions, that single point of failure could lead to a loss of control of multiple HCUs, potentially resulting in an inability to deploy control rods to regulate reactor flux. Therefore, there is a need for an apparatus, system, and method that improves the operation of the HCU of a CRDM to regulate nuclear flux in a nuclear reactor.

[0025] Referring now to FIG. 1 , a cross-sectional view of a CRDM 100 configured to enhance operation with an HCU 101 is shown, according to at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 1 , the CRDM 100 may include a water charging header 122 and a drive water header 120 in fluid communication with an HCU, which is in fluid communication with a water line 102, an insertion line 110, and a withdrawal line 126. The HCU 101 may include one or more DCVs 104a-d configured to open and close in various sequences to dampen fluid pressure on a collet piston 132 of the CRDM 100, thereby controlling the insertion and removal of control rods from the core as desired. The bottom of a reactor vessel 138 is also shown in FIG. 1 . Specifically, although HCU 101 of FIG. 1 includes four DCVs 104a-d configured to control fluid pressure to selectively insert and remove control rods from the reactor core, according to other non-limiting aspects, HCU 101 may include any number of DCVs 104a-d depending on user preference and / or intended use.

[0026] 1 , the CRDM 100 may further include a SCRAM inlet valve 105 and a SCRAM outlet valve 108 configured for emergency procedures requiring rapid insertion of control rods into the reactor vessel 138. For example, water supplied to the charging header 122 during SCRAM charging generates a high flow signal, thereby applying appropriate fluid pressure to the collet piston 132. Furthermore, a cooling orifice 112, a ball check valve 114, and a reactor pressure check valve 116 may be further implemented to ensure that the fluid and / or fluid pressure controlled by the HCU 101 effectively inserts and removes the control rods from the reactor vessel 138. The discharge header 118 may further ensure that back pressure caused by the fluid does not return to the HCU 101.

[0027] 1 , the CRDM 100 may include a number of mechanisms disposed within the structure to effectively insert and withdraw control rods into and from the reactor core. For example, the CRDM 100 may include a housing 128, an outer tube 152, an inner cylinder 150, and an index tube 148 configured to receive a drive piston 154 and a piston tube 146 having a damping orifice 130 for proper alignment and actuation. A collet piston 132 having collet fingers 144 and a collet spring 134 may be centered about the piston and configured to insert and withdraw control rods into and from the reactor vessel 138 as desired. A guide cap 136 and a stop piston 142 may also be disposed about the piston. The CRDM may further include a control rod coupling device or SPUD 140 configured to accommodate control rods that are inserted into and extracted from the reactor vessel 138 via drive pistons 154 in response to fluid pressure applied via the HCU 101, and more specifically via DCVs 104a-d of the HCU 100, during various operating conditions.

[0028] 2, an isometric view of the HCU 101 of the CRDM 100 of FIG. 1 is shown in accordance with at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 2, the HCU 101 may include a frame 202 configured to house various fluid components and valve assemblies necessary to shunt fluid pressure to the insertion line 110, the withdrawal line 126, and the SCRAM inlet and outlet valves 105, 108 so that the CRDM 100 moves control rods according to user preferences and / or intended applications. For example, the HCU 101 may include a SCRAM water accumulator 204, an inlet SCRAM valve and actuator 208, an isolation valve SCRAM discharge riser 210, an isolation valve cooling water riser 212, an isolation valve insert riser 214, an isolation valve discharge riser 216, an isolation valve SCRAM valve for pilot air 218, a water charging riser 220, an isolation valve extract riser 222, an isolation valve actuated water riser 224, a SCRAM pilot valve assembly 226, an outlet SCRAM valve and actuator 228, a shutoff valve water accumulator drain 230, a SCRAM accumulator cylinder 232, an accumulator pressure indicator 234, a cartridge valve accumulator for charging 236, and / or an accumulator instrumentation assembly 238. In other words, most of the components of the HCU 101 of FIG. 1 may be for communicating desired fluid pressures to the various components of the CRDM 100 (FIG. 1) for proper SCRAM function and / or operation during normal use.

[0029] However, according to non-limiting embodiments, FIG. 2 illustrates the DCVs 104a-d of the HCU 101 in more detail. For example, the HCU 101 may include two insertion DCVs 104a, 104d, an extraction DCV 104b, and / or an extraction and maintenance DCV 104c. The DCVs 104a-d of the HCU 101 may be connected to a manifold 206 and a wiring trough assembly 229. For example, the valve manifold 206 may be configured to converge the fluid lines DCVs 104a-d into one or more aggregated lines for inlet and / or outlet to upstream and / or downstream components. According to some non-limiting embodiments, the DCVs 104a-d may include solenoids. Accordingly, the DCVs 104a-d may be electrically connected to the wiring trough assembly 229, which may be configured to route electrical wiring to the various DCVs 104a-d. However, in accordance with the present disclosure, the wiring trough assembly 229 may further include control circuitry, such as the control circuit 300 of FIG. 3, configured to cause the DCVs 104a-d to insert and remove the control rods of a particular CRDM 100 (FIG. 1) relative to the reactor vessel 138 (FIG. 1). In other words, as further detailed herein, the HCU 101 may function as a mechanical / electrical assembly that is included and configured to enhance the operation of the DCVs 104a-d, and thus the operation of the CRDM 100 (FIG. 1).

[0030] Referring now to FIG. 3 , a schematic circuit diagram of a control circuit 300 of the HCU 101 of FIG. 2 is shown, in accordance with at least one non-limiting embodiment of the present disclosure. As previously mentioned, the control circuit 300 of FIG. 3 may be incorporated into the wiring trough assembly 229 of the HCU 101 of FIG. 2 to exclusively operate a single CRDM 100 ( FIG. 1 ). The control circuit 300 of FIG. 3 enables specific control of a particular CRDM, thereby providing more precise control and eliminating single points of failure common to conventional HCUs and conventional CRDMs. In other words, the control circuit 300 of FIG. 3 can improve the operation of the CRDM 101, which in turn can improve regulation of nuclear flux within the reactor vessel 138 ( FIG. 1 ).

[0031] According to a non-limiting embodiment of FIG. 3, the control circuit 300 may include a controller 302, such as a microprocessor. However, according to other non-limiting embodiments, the controller 302 may include one or more processing cores, processing units, processors, and / or DSPs, among other devices capable of controlling the functions of the HCU 101. According to yet other non-limiting embodiments, the controller 302 may include logic-based devices, such as PLDs, PLAs, and / or FPGAs, among others. The control circuit may further include one or more relay interfaces 324a-d, each of which may be electrically connected to a corresponding DCV 104a-d of the HCU 101 (FIG. 2) via one or more connectors 328a-d. Furthermore, each of the relay interfaces 324a-d may be electrically connected to a shunt resistor 326a-d configured to monitor the voltage drop across the respective DCV 104a-d of the HCU 101 (FIG. 2). The control circuit 300 may further include a plurality of isolated digital inputs 314a-d and a powered droop input 316 (eg, 4-20 mA, etc.).

[0032] 3, each isolation input 314a-d may be connected to circuitry configured to provide various inputs to the controller 302, such as a SCRAM test switch 304, an accumulator pressure 306 (both low and high pressure), a SCRAM supply valve limit 310, and / or a SCRAM solenoid pilot valve ("SSPV") status 312. Additionally, a powered loop input 316 (e.g., 4-20 mA, etc.) may be electrically connected to a pressure sensor 318 arranged to monitor the pressure in the accumulator. The powered loop input 316 may allow other compatible sensors to be operated using power received from, for example, a 4-20 mA process signal. Additionally, the controller 302 may be electrically connected to a temperature sensor 323 configured to monitor the local temperature associated with the system. The control circuitry 300 may further include various connectors 320, 322 that may be configured for programming (e.g., Universal Serial Bus) and / or diagnostic (e.g., RJ45, etc.) interfaces for the controller 302.

[0033] 3, control circuitry 300 may further include communications circuitry 336 configured to establish communications between controller 302 and overall control rod drive control system 622, specifically with head controller 624 (FIG. 6) via input / output components 618a-d (FIG. 6) and with one or more communications modules 628a, 628b (FIG. 6) via interface bus and communications connector 328g. For example, according to some non-limiting embodiments, communications circuitry 336 may include an implementation of one or more standard Fieldbus communications protocols. For example, use of a standard Fieldbus communications protocol may allow control circuitry 300 to operate independently of its own communications protocol, thereby improving reliability and redundancy across the communications interface.

[0034] Additionally, the control circuit 300 of FIG. 3 may be configured to be electrically connected to one or more external power sources via one or more connectors 328g, 328f. According to non-limiting embodiments of FIG. 3, the control circuit may be electrically connected to two power sources, providing additional redundancy that further improves the HCU 101 (FIG. 2) over conventional devices that have a single point of failure for multiple HCUs and are typically powered by a single power source. The supplied power may be filtered by one or more filters 330a, 330b and / or pass through one or more AC / DC converter filters 332a, 332b before being distributed to components downstream of the control circuit 300. For example, the internal power distribution circuit 334 may receive the filtered and converted inputs and provide them to the controller 302 and / or other peripheral components of the control circuit 300 via one or more lines. According to some non-limiting embodiments, the internal power distribution circuit 334 may include a compact, isolated AC-DC power supply.

[0035] Thus, it should be appreciated that the control circuitry 300 of FIG. 3 distinguishes the HCU 101 (FIG. 2) and CRDM 100 (FIG. 1) from conventional devices by facilitating the operation of the local HCU 101 (FIG. 2), and more precisely, by facilitating the control of the DCVs 104a-d. Nevertheless, the control circuitry 300 of each HCU 101 (FIG. 2) is capable of communicating with and responding to a central controller for the reactor, such as controller 600 of FIG. 6, via a standard Fieldbus communication protocol. In other words, each control circuitry 300 can monitor and control each HCU 101 (FIG. 2) with specificity beyond the capabilities of conventional systems.

[0036] For example, the control circuit 300 of FIG. 3 may receive operation start and direction commands from the overall regulating logic controller and may internally process the timing sequence of actuation of the DCVs 104a-d to initiate a single extraction or insertion step or continuous extractions or insertions, as described with reference to FIG. 5. Additionally, each control circuit 300 may monitor process signals (e.g., limit / pressure switches, etc.) from the external HCU 101 (FIG. 2) and provide status information to the regulating logic controller via a fieldbus interface. The control circuit 300 may also monitor the current and voltage applied to each DCV 104a-d for appropriate waveform values ​​and may indicate whether they are performing as intended. Similarly, the control circuit 300 may monitor the current and voltage applied to the DCVs 104a-d and may use resistance and temperature calculations to monitor the health and baseline operation of the DCVs 104a-d. The control circuit 300 may further monitor the current applied to the DCVs 104a-d for an indication of the normality of solenoid operation, as will be described with further reference to Figure 4. Additionally, the control circuit 300 may monitor the current applied to the DCVs and indicate whether current is present when current is not needed.

[0037] Additionally, the control circuit 300 of Figure 3 may monitor local power sources and indicate whether they are out of range or unavailable, and may provide the same to the coordination logic controller. The control circuit 300 may receive adjustable setpoints for internal control parameters from the coordination controller via fieldbus, and according to some non-limiting embodiments, the control circuit 300 may automatically take any action, such as inhibiting control rod movement, if an abnormal condition is detected. All abnormal conditions may be sent to the coordination controller for system-level analysis and further commands.

[0038] Referring now to FIG. 4, a chart 400 illustrating enhanced operation of the HCU 101 (FIG. 2) enabled by the control circuit 300 of FIG. 3 in accordance with at least one non-limiting embodiment of the present disclosure is shown. For example, the control circuit 300 (FIG. 3) may acquire data and detect parameters (e.g., notch 404) illustrated in the chart 400 for use in connection with the external monitoring and signal processing functions of the HCU 101 (FIG. 2) discussed above. The chart 400 may illustrate, for example, the DCV current monitoring and engagement detection functions provided by the apparatus, systems, and methods disclosed herein. Specifically, the chart 400 of FIG. 4 illustrates the advanced monitoring functions provided by the control circuit 300 of FIG. 3. According to a non-limiting embodiment of FIG. 4, the chart may illustrate current and voltage measurements over time for each solenoid valve in the DCVs 104a-d. For example, the chart 400 may include a depiction of the maximum 406a and minimum 406b resistance calculations for a particular solenoid. The chart 400 may further include a depiction of the initial high peak of the solenoid's overshoot 402 (e.g., the first measurement above the depicted maximum value 406a). The chart 400 may further include one or more widgets 408, 410 configured to display key metrics related to the solenoid being monitored by the control circuit 300 of FIG. 3. For example, the first widget 408 may include a numerical representation of the expected voltage, resistance, and change over time for each of the maximum 406a and minimum 406b calculations shown on the chart 400. Similarly, the second widget 410 may include similar metrics related to a particular voltage, resistance, or impedance measurement at a particular time.

[0039] With further reference to FIG. 4, it will be appreciated that the control circuit 300 of FIG. 3 may be used to determine changes in inductance of the solenoid valves of each of the DCVs 104a-d over time. For example, the control circuit 300 of FIG. 3 may control four DCVs 104a-d to open and close fluid lines to insert and / or withdraw control rods. According to a non-limiting embodiment in which the DCVs 104a-d include solenoid valves, each of the DCVs 104a-d may experience changes in inductance that may be monitored to determine proper valve function. According to a non-limiting embodiment in which the control circuit 400 includes a microcontroller, the control circuit 300 may generate feedback based on the measured inductance to determine that the DCVs 104a-d are functioning properly and that the plungers have actually moved.

[0040] For example, according to a non-limiting embodiment of FIG. 4, the chart shows a notch 404 that can be detected by monitoring by the control circuit 300 (FIG. 3), and that can only occur when the plunger initially engages due to proper operation of the DCVs 104a-d. According to a non-limiting embodiment in which the DCVs 104a-d include solenoid valves, the notch 404 can be related to a change in inductance with the DCVs 104a-d resulting from the initial engagement of the plunger within the solenoid valve. In other words, the notch 404 can appear when static friction is released. Thereafter, because the plunger remains seated, the chart 400 does not show any additional “glitches” or notches 404 until power is removed and the spring retracts the plunger. Over time, if the notch 404 (or engagement “glitch”) moves to the left of the chart 400, this may be an indication that the spring may be weakening due to a decreasing current threshold. According to other non-limiting embodiments, the operating temperature of each of the DCVs 104a-d may be monitored by monitoring current and voltage to generate resistance and temperature based on the constants of the materials (e.g., copper, etc.) in which they are implemented. In other words, the chart 400 of FIG. 4 may serve as a health check for each of the DCVs 104a-d, which may be individually monitored by the control circuit 300 of FIG. 3. Thus, the control circuit 300 of FIG. 3 may be used to provide a more intelligent, data-driven approach to preventive maintenance, thereby improving the operation of the HCU 101 (FIG. 2) and / or the CRDM 100 (FIG. 1).

[0041] Referring now to FIG. 5, another chart 500 illustrating the improved operation of the HCU 101 (FIG. 2) enabled by the control circuit 300 of FIG. 3, in accordance with at least one non-limiting aspect of the present disclosure, is shown. The chart 500 may illustrate, for example, the operational timing of the DCVs. Specifically, the chart 500 of FIG. 5 illustrates the control of the DCVs 104a-d of the HCU 101 of FIG. 2. Accordingly, the chart 500 illustrates four operational modes, including an insertion sequence 502, an extraction sequence 504, a continuous insertion sequence 506, and a continuous extraction sequence 508, along with the respective timing of each operational mode. For example, according to the non-limiting aspect of FIG. 5, the insertion sequence 502 may include an insertion operation 512 lasting 2.9 seconds and a sustain operation 514 lasting 5.3 seconds. The extraction sequence 504 may include an insertion operation 522 lasting 0.6 seconds, an extraction operation 524 lasting 1.5 seconds, and a maintenance operation 526 lasting 6.0 seconds. Of course, it should be understood that specific references to particular times or durations are merely exemplary and may not be equivalent in other non-limiting embodiments. The sequential insertion sequence 506 may include instructions to sequentially insert one or more control rods until a stop is commanded, such as by releasing a sequential insertion pushbutton. The sequential extraction sequence 508 may include instructions to sequentially extract one or more control rods until a stop is commanded, such as by releasing a sequential insertion pushbutton. After a command to stop the sequential extraction sequence 508 is issued, a maintenance function may begin. According to the non-limiting embodiment of FIG. 5, for example, numbers 120-123 may correspond to DCVs 104a-d of the HCU 101, respectively.

[0042] Conventional systems implement a single controller at the head end to control the insertion and removal of specific control rods. However, the control circuit 300 (FIG. 3) of the HCU 101 (FIG. 2) allows high-speed operation at the local level in the HCU 101 (FIG. 2). This allows for much higher resolution control of each specific control rod, reducing lag and potential blockage between the head and the HCU 101 (FIG. 2) being moved, allowing the control circuit 300 (FIG. 3) to move the control rod within the millisecond range. Notably, this improves the reliability of control rod operation by eliminating redundant mechanisms in the conventional control path. In other words, the control circuit 300 of FIG. 3 allows users to adjust setpoints at the HCU 101 (FIG. 1) level (a lower level in the overall assembly), reducing the need for generic timing and allowing specific timing for each control rod. Because the control circuit 300 of Figure 3 has its own intelligence to directly control each control rod, there is no need for "intermediate" circuits or subsystems to communicate control information to the HCU 101 (Figure 2) at a granular level before control can be achieved. For example, high-level instructions may still be required from the head controller, but detailed control is handled at a local level.

[0043] Referring now to FIG. 6 , a circuit schematic diagram of a controller 600 for a system configured to interface with multiple HCUs is shown, in accordance with at least one non-limiting embodiment of the present disclosure. It will be appreciated that the controller 600 may be a header controller configured to manage various interfaces for a system including multiple HCUs, with each HCU having its own control circuit 300 ( FIG. 3 ). For example, the controller 600 may include and control human-machine interfaces, outside plant interfaces, and / or control rod motion interlocks and / or permissives, which may be driven by system requirements. According to a non-limiting embodiment of FIG. 6 , the controller may include a control rod position display module 610, a control rod selection control module 612, a remote input / output module 614, a control rod drive control system (“RDCS”) module 622, and / or a control rod worth monitoring (“RWM”) module 630, all communicatively connected via a network infrastructure 620. In other words, the controller 600 may be configured to manage various interfaces such that the operation of the CRDM 100 (FIG. 1) is improved through more accurate operation of the HCU 101 (FIG. 2) implemented by the control circuit 300 of FIG. 3.

[0044] 6, the control rod position display module 610 of the controller 600 may include a first computing device 605a communicatively connected to the display 602 and / or the touchscreen 604a, such that the control rod position display module 610 can display the current position of the control rod at any given time. Similarly, the control rod selection control module 612 may include a second computing device 605b communicatively connected to the touchscreen 604b and / or any other control devices 606 to enable a user to select and control a particular CRDM 100 (FIG. 1) in the system. Signals sent to and / or from the control rod selection control module 612 may be sent to the rest of the system interface via a remote input / output module 614, which may include one or more node interfaces 616a, 616b and one or more input / output components 618a-d. In other words, the control rod position display module 610, the control rod selection control module 612, and the remote input / output module 614 may be configured as a human-machine interface for the system, allowing a user to monitor and communicate with the CRDM 100 (FIG. 1) and the HCU 101 (FIG. 2), among other subsystems, as needed. According to some non-limiting embodiments, parameters of the controller, including operating parameters such as adjustable timing and alarm values, may be adjusted from the displays 602, 606a via the communication interface.

[0045] 6, the RDCS module 622 may include one or more controllers 624a, 624b, one or more communication modules 628a, 628b (e.g., Fieldbus, Ethernet, etc.), one or more input / output components 618e-h, and / or a power module 626, collectively configured to interface with one or more of the HCUs 638a-d via one or more interface components 636a-d. It will be appreciated that each of the one or more of the HCUs 638a-d may be configured similarly to the HCU 101 of FIG. 2 and, therefore, may include the HCU control circuitry 300 as shown and described with reference to FIG. 3. Furthermore, the one or more interface components 636a-d may be configured to communicate with one another independent of the RDCS module 622. Specifically, the one or more input / output components 618e-h may be configured to communicate with multiple channels, each channel representing an external system interface. Additionally, one or more controllers 624a, 624b may be configured to communicate with the remote input / output module 614 via a network infrastructure 620, which may include a communications protocol such as Ethernet, and, of course, communications may be coordinated and / or standardized via one or more communications circuits 628a, 628b.

[0046] 6, the RWM module 630 may include one or more controllers 624c, 624d, one or more input / output components 618i-l, one or more electronic load controllers (“ELCs”) 632a, 632b, and / or one or more switches 636a, 636b, which are collectively configured to provide instructions regarding the specific controls to be applied to each control rod via the CRDM 100 (FIG. 1). The one or more switches may be connected to one or more control rod position indication systems (“RPIS”) 640a, 640b configured to provide information and assist in control rod control instructions. Specifically, the one or more input / output components 618i-l may be configured to communicate with several external system interfaces as well as the RDCS module 622.

[0047] According to certain non-limiting embodiments, the controller 600 of FIG. 6 may be further configured to execute a RWM sequence application 642, which may provide further information and assist in control rod control instruction. Similarly, the controller 600 of FIG. 6 may be communicatively connected to one or more plant computers 644 via a data link 646 of the network architecture 620. According to certain non-limiting embodiments, the controller 600 of FIG. 6 may be custom-made. According to other non-limiting embodiments, the controller 600 of FIG. 6 may be implemented using commercially available products. In any event, the controller 600 of FIG. 6 may be configured to communicate with one or more of the HCUs 638a-d to manage overall system coordination (e.g., via the RDCS module 622) and to provide and / or receive feedback to / from human-machine interfaces (e.g., via the control rod position display module 610, the control rod selection control module 612, and the remote input / output module 614). Meanwhile, the lower-level control circuitry 300 (FIG. 3) may be configured to control the detailed functions of each HCU 101 (FIG. 2), including opening and closing the individual DCVs 104a-d (FIG. 1) and monitoring and managing systems and alarms. Similarly, according to a non-limiting embodiment in which the controller 600 of FIG. 6 and the control circuitry 300 of FIG. 3 are implemented by software-based devices (e.g., microprocessors, processors, etc.), further benefits can be obtained through software or firmware upgrades. In other words, the controller 600 of FIG. 6 and the control circuitry 300 of FIG. 3 can be continuously improved.

[0048] 7, a method 700 for improving operation of HCU 101 (FIG. 2) is illustrated in accordance with at least one non-limiting aspect of the present disclosure. For example, method 700 of FIG. 7 may be performed by control circuit 300 (FIG. 3) of HCU 101 (FIG. 2). According to the non-limiting aspect of FIG. 7, method 700 includes detecting (702) a current 702 associated with each of multiple valves 104a-d (FIG. 2) of HCU 101 (FIG. 2) and detecting (704) a voltage 704 associated with each of multiple valves 104a-d (FIG. 2) of HCU 101 (FIG. 2). The method 700 may further include identifying (706) parameters associated with each of the plurality of valves 104a-d (FIG. 2) of the HCU 101 (FIG. 2) based on the detected voltage and the detected current, and generating (708) an operating sequence 502, 504, 506, 508 (FIG. 5) based on the identified parameters. Finally, the method 700 may include damping (710) fluid pressure within the CRDM 100 (FIG. 1) using the plurality of valves 104a-d (FIG. 2) such that the fluid pressure causes the control rods of the CRDM 100 (FIG. 1) to execute the generated operating sequence 502, 504, 506, 508 (FIG. 5).

[0049] Referring now to FIG. 8, another method 800 for improving operation of HCU 101 (FIG. 2) is illustrated in accordance with at least one non-limiting aspect of the present disclosure. For example, method 800 of FIG. 8 may be performed by control circuitry 300 (FIG. 3) of HCU 101 (FIG. 2). According to the non-limiting aspect of FIG. 8, method 800 may include receiving (802) a signal from one or more controllers 624a, 624b (FIG. 6) of RDCS module 622 (FIG. 6) via one or more communication modules 628a, 628b (FIG. 6). The method 800 may further include generating (804) an operating sequence 502, 504, 506, 508 (FIG. 5) based on the received signal, and attenuating (806) fluid pressure within the CRDM 100 (FIG. 1) using the plurality of valves 104a-d (FIG. 2) such that the fluid pressure causes the control rods of the CRDM 100 (FIG. 1) to execute the generated operating sequence 502, 504, 506, 508 (FIG. 5). During that process, the method 800 may include detecting (808) a current associated with each of the plurality of valves 104a-d (FIG. 2) of the HCU 101 (FIG. 2) and detecting (810) a voltage associated with each of the plurality of valves 104a-d (FIG. 2) of the HCU 101 (FIG. 2). Then, if necessary, the method may include identifying (812) parameters associated with each of the plurality of valves 104a-d (FIG. 2) of the HCU 101 (FIG. 2) based on the detected voltage and the detected current. Based on the identified parameters, the method 800 may include determining (814) whether the operation sequence is completed and / or whether the operation sequence is successful. If the operation is successful, the method 800 may include indicating (816) that the operation sequence is successful and completed. If the operation is not successful, the method 800 may include generating (818) health and / or status information related to improper execution of the operation sequence.

[0050] Various aspects of the subject matter described herein are set forth in the following numbered sections:

[0051] Item 1: A hydraulic control unit ("HCU") configured to control a control rod drive mechanism ("CRDM") configured to control nuclear flux produced by a nuclear reactor, the HCU including: a plurality of valves configured to dampen fluid pressure within the CRDM, whereby damping the fluid pressure causes control rods of the CRDM to be inserted into and removed from a reactor vessel of the nuclear reactor; and a control circuit, the control circuit including: a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves; a controller electrically connected to the plurality of relay interfaces; and a communication circuit communicatively connected to a header controller, the communication circuit configured to send and receive signals between the controller and the header controller.

[0052] Item 2: The HCU described in Item 1, wherein the control circuit is configured to detect a current associated with each valve of the plurality of valves and a voltage associated with each valve of the plurality of valves.

[0053] Item 3: The HCU of either item 1 or item 2, wherein the control circuit is further configured to determine a resistance associated with each valve of the plurality of valves based on a material constant associated with each valve of the plurality of valves, a detected current associated with each valve of the plurality of valves, and a detected voltage associated with each valve of the plurality of valves.

[0054] Item 4: The HCU described in any one of items 1 to 3, wherein the control circuit is further configured to determine a temperature associated with each valve of the plurality of valves based on a material constant associated with each valve of the plurality of valves, a current detected associated with each valve of the plurality of valves, and a voltage detected associated with each valve of the plurality of valves.

[0055] Item 5: The HCU according to any one of Items 1 to 4, wherein at least one of the plurality of valves is a solenoid valve.

[0056] Item 6: The HCU described in any of items 1 to 5, wherein the control circuit is further configured to determine an inductance associated with at least one valve of the plurality of valves based on a current detected associated with each valve of the plurality of valves.

[0057] Item 7: An HCU according to any one of items 1 to 6, wherein the identification is further based on material constants associated with each valve of the plurality of valves.

[0058] Item 8: An HCU described in any of items 1 to 7, wherein the control circuit is configured to cause the multiple valves to attenuate fluid pressure within the CRDM so that the control rods perform at least one of an insertion sequence, an extraction sequence, a continuous insertion sequence, a continuous extraction sequence, and combinations thereof.

[0059] Item 9: The HCU according to any one of Items 1 to 8, wherein each of the insertion sequence, extraction sequence, consecutive insertion sequence, and consecutive extraction sequence can be started upon receiving a general operation request command from the header controller.

[0060] Item 10: An HCU described in any of items 1 to 9, wherein each of the insertion sequence, extraction sequence, consecutive insertion sequence, and consecutive extraction sequence includes at least one operation, and at least one operation of the insertion sequence, extraction sequence, and consecutive insertion sequence includes a predetermined adjustable time specified by the control circuit.

[0061] Clause 11: A system configured to control a plurality of control rod drive mechanisms ("CRDMs") configured to control nuclear flux produced by a nuclear reactor, the system including: a header controller; and a plurality of hydraulic control units ("HCUs"), each HCU of the plurality of HCUs including a plurality of valves configured to attenuate fluid pressure within a CRDM of the plurality of CRDMs, whereby attenuating the fluid pressure causes control rods of the CRDMs of the plurality of CRDMs to be inserted into and removed from a reactor vessel of the nuclear reactor; and a control circuit, the control circuit including a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves; a controller electrically connected to the plurality of relay interfaces; and a communication circuit communicatively connected to the header controller, the communication circuit configured to send and receive signals between the controller and the header controller.

[0062] Item 12: The system of item 11, wherein the control circuit is configured to detect a current associated with each valve of the plurality of valves and a voltage associated with each valve of the plurality of valves.

[0063] Item 13: The system of either item 11 or item 12, wherein the control circuit is further configured to determine a resistance associated with each valve of the plurality of valves based on a material constant associated with each valve of the plurality of valves, a detected current associated with each valve of the plurality of valves, and a detected voltage associated with each valve of the plurality of valves.

[0064] Item 14: The system of any of items 11 to 13, wherein the control circuit is further configured to determine a temperature associated with each valve of the plurality of valves based on a material constant associated with each valve of the plurality of valves, a detected current associated with each valve of the plurality of valves, and a detected voltage associated with each valve of the plurality of valves.

[0065] Item 15: The system according to any one of Items 11 to 14, wherein at least one of the plurality of valves is a solenoid valve.

[0066] Item 16: The system of any of items 11 to 15, wherein the control circuit is further configured to determine an inductance associated with at least one valve of the plurality of valves based on a detected current associated with each valve of the plurality of valves and a detected voltage associated with each valve of the plurality of valves.

[0067] Item 17: A system described in any of items 11 to 16, wherein the control circuit is configured to cause the multiple valves to attenuate fluid pressure within the CRDM so that the control rod performs at least one of an insertion sequence, an extraction sequence, a sequential insertion sequence, a sequential extraction sequence, and combinations thereof.

[0068] Clause 18: A method for controlling nuclear flux produced by a nuclear reactor, the method comprising: receiving a signal from a control rod drive control system ("RDCS") module via a control circuit of a hydraulic control unit ("HCU"); generating an operating sequence based on the received signal via the control circuit of the HCU; damping fluid pressure in the control rod drive mechanism ("CRDM") using a plurality of valves via the control circuit of the HCU so that the fluid pressure causes the control rods of the CRDM to perform the generated operating sequence; detecting currents associated with each of the plurality of valves of the HCU via the control circuit of the HCU; detecting voltages associated with each of the plurality of valves of the HCU via the control circuit of the HCU; identifying parameters associated with each of the plurality of valves of the HCU via the control circuit of the HCU based on the detected voltages and detected currents; and identifying a state of the operating sequence via the control circuit of the HCU based on the identified parameters.

[0069] Clause 19: The method of clause 18, wherein the determined parameters include at least one of a resistance associated with each valve of the plurality of valves and a temperature associated with each valve of the plurality of valves.

[0070] Clause 20: The method of either clause 18 or clause 19, wherein the operation sequence includes at least one of an insert sequence, an extract sequence, a consecutive insert sequence, a consecutive extract sequence, and combinations thereof.

[0071] 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, their 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, where necessary, the disclosure set forth herein shall supersede any conflicting materials incorporated herein by reference, and the disclosure expressly set forth in this application shall control.

[0072] The present invention has been described with reference to various exemplary and illustrative embodiments. It should be understood that the embodiments described herein provide illustrative features of various details of the various embodiments of the disclosed invention, and thus, unless otherwise indicated, it should be understood that, to the extent possible, one or more features, elements, components, elements, components, structures, modules, and / or aspects of the disclosed embodiments may be combined, separated, substituted, and / or rearranged with / with respect to one or more other features, elements, components, elements, components, 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 any exemplary embodiments may be variously substituted, modified, or combined without departing from the scope of the invention. Moreover, those skilled in the art, upon reading this specification, will recognize or be able to recognize, with no more than routine experimentation, many equivalents to the various embodiments of the invention described herein. Accordingly, the present invention is not limited by the description of the various embodiments, but rather by the scope of the claims.

[0073] Those skilled in the art will recognize that the terms used herein, generally, and in the appended claims (e.g., the body of the appended claims), in particular, are typically "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 word "comprising" should be interpreted as "including, but not limited to," etc.). Those skilled in the art will further understand that if a specific number of an introduced element is intended, such intention will be explicitly recited in the claim; otherwise, no such intention exists. For example, as an aid to understanding, the appended claims may include the introductory phrases "at least one" and "one or more" to introduce elements. However, the use of such phrases should not be construed as limiting a particular claim that includes an element so introduced by the indefinite article "a" or "an" to claims that include only one such element, even if that claim includes 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"). The same applies to definite articles used to introduce elements.

[0074] Additionally, even when the number of elements in an introduced claim is explicitly recited, those skilled in the art will recognize that this generally translates to mean at least the recited number of elements (e.g., a phrase "two elements" without other modifiers generally translates to at least two elements, or more than two elements). Furthermore, when phrases similar to "at least one of A, B, and C, etc." are used, such phrases are generally intended to have the meaning that one skilled in the art would understand the phrase (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, a system having only B, a system having only C, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.). When phrases similar to "at least one of A, B, or C, etc." are used, such phrases are generally intended to have the meaning that one of ordinary skill in the art would understand the phrase (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, a system having only B, a system having only C, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.). Those of ordinary skill in the art will further understand that disjunctive words and / or disjunctive phrases presenting two or more alternative terms, whether in the specification, claims, or drawings, should generally be understood to contemplate the possibility of including one of the words, either of the words, or both words, unless the context dictates otherwise. For example, the phrase "A or B" is generally understood to include the possibilities of "A," or "B," or "A and B."

[0075] With respect to the appended claims, those skilled in the art will understand that the operations described therein may generally be performed in any order. Also, while various operational flow diagrams are shown in a sequence, it should be understood that various operations may be performed in an order other than that shown, or may be performed simultaneously. Examples of such alternative sequences include overlapping, interleaved, interrupted, reordered, incremental, and preparatory sequences. Furthermore, past tense adjectives such as "corresponding to" and "related to" are generally not intended to exclude such variations unless the context dictates otherwise.

[0076] It should be noted that references to "one embodiment," "an embodiment," "one 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 one 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.

[0077] As used herein, the singular forms "a," "an," and "the" include the plural forms as well, unless the context clearly indicates otherwise.

[0078] For example, but not limited to, directional terms used herein such as up, down, left, right, lower, upper, 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.

[0079] As used in this disclosure, unless otherwise specified, the terms "substantially," "about," or "nearly" refer to an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the terms "substantially," "about," or "nearly" mean within 1, 2, 3, or 4 standard deviations. In certain embodiments, the terms "substantially," "about," or "nearly" mean within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a value or range.

[0080] As used herein, unless otherwise noted, all numerical parameters should be understood to be prefaced and modified in all instances by the word "about." Such numerical parameters have the inherent variability characteristic of the underlying measurement techniques used 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.

[0081] 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 value of "1" and the recited maximum value of "100," i.e., all subranges with a minimum value of 1 or greater and a maximum value of 10 or less. Also, all ranges recited herein include their endpoints. For example, a range of "1 to 100" includes the endpoints 1 and 100. Each maximum numerical limitation recited herein is intended to include all subranges subsumed therein, and each minimum numerical limitation recited herein is intended to include all subranges subsumed therein. Accordingly, applicants reserve the right to amend this specification, including the claims, to expressly recite any subranges subsumed within any explicitly recited range. All such ranges are inherently set forth herein.

[0082] 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 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.

[0083] The words "comprise" (and any form of "comprise," such as "comprised" or "comprising"), "have" (and any form of "have," such as "had" or "having"), "include" (and any form of "include," such as "included" or "containing"), and "contain" (and any form of "contain," such as "contained" or "containing") are open-ended linking verbs. Thus, a system that "comprises," "has," "includes," or "contains" one or more elements has those one or more elements, but is not limited to having only those one or more elements. Similarly, an element of a system, device, or apparatus that "comprises," "has," "includes," or "contains" one or more features has those one or more features, but is not limited to having only those one or more features.

Claims

1. 1. A hydraulic control unit ("HCU") configured to control a control rod drive mechanism ("CRDM") configured to control nuclear flux produced by a nuclear reactor, The HCU comprises: a plurality of valves configured to attenuate fluid pressure within the CRDM, wherein attenuating the fluid pressure inserts and removes control rods of the CRDM into and from a reactor vessel of the nuclear reactor; a control circuit; The control circuit a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves; a controller electrically connected to the plurality of relay interfaces; a communication circuit communicatively connected to the header controller; the communication circuitry is configured to transmit and receive signals between the controller and the header controller; HCU.

2. the control circuit is configured to sense a current associated with each valve of the plurality of valves and a voltage associated with each valve of the plurality of valves. The HCU of claim 1 .

3. the control circuitry is further configured to determine a resistance associated with each valve of the plurality of valves based on a material constant associated with each valve of the plurality of valves, the detected current associated with each valve of the plurality of valves, and the detected voltage associated with each valve of the plurality of valves. The HCU of claim 2.

4. the control circuitry is further configured to determine a temperature associated with each of the plurality of valves based on a material constant associated with each of the plurality of valves, the detected current associated with each of the plurality of valves, and the detected voltage associated with each of the plurality of valves. The HCU of claim 2.

5. At least one valve of the plurality of valves is a solenoid valve. The HCU of claim 4.

6. the control circuitry is further configured to determine an inductance associated with the at least one valve of the plurality of valves based on the detected current associated with each valve of the plurality of valves. The HCU of claim 5.

7. the identifying is further based on a material constant associated with each valve of the plurality of valves. The HCU of claim 6.

8. the control circuit is configured to cause the plurality of valves to damp the fluid pressure within the CRDM such that the control rods perform at least one of an insertion sequence, an extraction sequence, a sequential insertion sequence, a sequential extraction sequence, and combinations thereof. The HCU of claim 1 .

9. each of the insertion sequence, the extraction sequence, the successive insertion sequence, and the successive extraction sequence can be initiated upon receiving an operation request command from the header controller; The HCU of claim 8.

10. each of the insertion sequence, the extraction sequence, the successive insertion sequence, and the successive extraction sequence comprises at least one operation; the at least one operation of the insertion sequence, the extraction sequence, and the continuous insertion sequence has a predetermined adjustable time specified by the control circuit; The HCU of claim 8.

11. 1. A system configured to control a plurality of control rod drive mechanisms (“CRDMs”) configured to control nuclear flux produced by a nuclear reactor, comprising: The system comprises: Header Controller, a plurality of hydraulic control units ("HCUs"); Each HCU among the plurality of HCUs a plurality of valves configured to dampen fluid pressure within a CRDM of the plurality of CRDMs, wherein damping the fluid pressure extends or withdraws a control rod of a CRDM of the plurality of CRDMs from or into a reactor vessel of the nuclear reactor; a control circuit; The control circuit a plurality of relay interfaces, each relay of the plurality of relay interfaces electrically connected to a valve of the plurality of valves; a controller electrically connected to the plurality of relay interfaces; a communication circuit communicatively connected to the header controller; the communication circuitry is configured to transmit and receive signals between the controller and the header controller; system.

12. the control circuit is configured to sense a current associated with each valve of the plurality of valves and a voltage associated with each valve of the plurality of valves. The system of claim 11.

13. the control circuitry is further configured to determine a resistance associated with each valve of the plurality of valves based on a material constant associated with each valve of the plurality of valves, the detected current associated with each valve of the plurality of valves, and the detected voltage associated with each valve of the plurality of valves. The system of claim 12.

14. the control circuitry is further configured to determine a temperature associated with each of the plurality of valves based on a material constant associated with each of the plurality of valves, the detected current associated with each of the plurality of valves, and the detected voltage associated with each of the plurality of valves. The system of claim 12.

15. At least one valve of the plurality of valves is a solenoid valve. The system of claim 13.

16. the control circuitry is further configured to determine an inductance associated with the at least one valve of the plurality of valves based on the detected current associated with each valve of the plurality of valves and the detected voltage associated with each valve of the plurality of valves.

16. The system of claim 15.

17. the control circuit is configured to cause the plurality of valves to damp the fluid pressure within the CRDM such that the control rods perform at least one of an insertion sequence, an extraction sequence, a sequential insertion sequence, a sequential extraction sequence, and combinations thereof. The system of claim 13.

18. 1. A method for controlling nuclear flux produced by a nuclear reactor, comprising: The method comprises: receiving a signal from a control rod drive control system ("RDCS") module via a hydraulic control unit ("HCU") control circuit; generating an operation sequence based on the received signal via the control circuitry of the HCU; damping the fluid pressure in the control rod drive mechanism ("CRDM") using the plurality of valves via the control circuitry of the HCU such that the fluid pressure causes control rods of the CRDM to perform the generated sequence of operations; Detecting, via the control circuitry of the HCU, a current associated with each of a plurality of valves of the HCU; detecting, via the control circuitry of the HCU, a voltage associated with each valve of the plurality of valves of the HCU; determining, via the control circuitry of the HCU, a parameter associated with each of the plurality of valves of the HCU based on the detected voltage and the detected current; and determining, via the control circuitry of the HCU, a state of the operational sequence based on the determined parameters. method.

19. the determined parameters comprise at least one of a resistance associated with each valve of the plurality of valves and a temperature associated with each valve of the plurality of valves.

20. The method of claim 18.

20. the operation sequence comprises at least one of an insert sequence, an extract sequence, a successive insert sequence, a successive extract sequence, and combinations thereof; 20. The method of claim 18.

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