Abstract: A molten fuel salt nuclear reactor core assembly including a fluid neutron reflecting material defining a fast spectrum fuel volume configured to breed fissile fuel from fertile fuel, a first inlet channel, and a first outlet channel through which cooled molten fuel salt can enter and heated molten fuel salt can exit the fast spectrum fuel volume. The core assembly also includes a set of neutron absorbing members sized to fit within the fast spectrum fuel volume. The set of neutron absorbing members define a thermal spectrum fuel volume for a fission reaction of the fissile fuel, a second inlet channel, and a second outlet channel through which cooled molten fuel salt can enter and heated molten fuel salt can exit the thermal spectrum fuel volume.

Abstract: Provided is a control rod motion monitoring method and a control rod motion monitoring system, in which a control rod insertion in an entire core is monitored at all time during operation of a reactor and, when an abnormality occurs, a signal is issued to a countermeasure device that automatically starts operation and an alarm is issued to prompt operation of an operator. An LPRM detector in an LPRM assembly of the entire core is divided into four channels for each height; indicated values are averaged at all time; the average indicated value is compared with a set point; and a signal is issued to a countermeasure device when an abnormality occurs.

Abstract: A boiling water reactor system includes a reactor vessel including a reactor core. A steam line is in communication with the reactor core and a turbine that is connected to an electrical generator. A dry standby liquid control system includes a standby vessel containing dry powder containing boron and including a high pressure water supply in communication with the standby vessel via a first closed valve, wherein the standby vessel is in communication with the reactor vessel via a second closed valve.

Abstract: A cooling air amount adjustment device of a concrete cask is provided. The device includes at least one of an air outlet port opening level adjustment mechanism and an air inlet port opening level adjustment mechanism which are adapted to automatically perform adjustment to reduce a flow rate of a cooling air when a temperature of the cooling air at an air outlet port is lower than an adjustment reference temperature, and adjustment to increase the flow rate of the cooling air so as to restore the flow rate of the cooling air when the temperature of the cooling air at the air outlet port is higher than the adjustment reference temperature.

Abstract: The method and system for control of oxygen concentration in the coolant of a reactor plant including a reactor, coolant in the reactor, gas system, mass-exchange apparatus, disperser and an oxygen sensor in the coolant have been disclosed. The method includes the following steps implemented by the system: estimation of the oxygen concentration; comparison of the oxygen concentration with the permissible value; if the oxygen concentration is reduced, comparison of the reduction value and\or rate with the corresponding threshold value; if the reduction value and\or rate of oxygen concentration is below the threshold value, activation of the mass-exchange apparatus; if the reduction value and/or rate of oxygen concentration is above the corresponding threshold value, supply of oxygen-containing gas from the gas system to the near-coolant space and/or activation of the disperser.

Abstract: An energy storage apparatus includes a first circuit containing a first phase change material, a second circuit containing a second phase change material, and a heat pump having a cold side heat exchanger thermally coupled to the first circuit and a hot side heat exchanger thermally coupled to the second circuit. The apparatus is operable in a charging mode, a storage mode, and a discharge mode. In the charging mode the heat pump is energized to cool the first phase change material and heat the second phase change material. In the storage mode the first phase change material is stored in a first storage vessel and the second phase change material is stored as a pressurized vapor in a second storage vessel. In the discharge mode vaporized first phase change material is expanded by a first expander, or the vaporized second phase change material is expanded by a second expander.

Abstract: A nuclear reactor power regulator adjusts reactor output based on a reactor output target value and a reactor output change rate. The regulator includes a reactor output calculating device that performs computation based on a thermal equilibrium from power signals of plant parameters to calculate a reactor output signal. A correcting device corrects a continuously obtained reactor output equivalent signal that is considered to be equivalent to a reactor output at a calculation interval of the output signal, so that the output equivalent signal coincides with the output signal. The correcting device calculates a continuous corrected output equivalent signal. A reactor output controlling device calculates a reactor output control signal for controlling the output of the reactor, using the corrected reactor output equivalent signal, the reactor output target value, and the reactor output change rate. A reactor output controller is operated based on the reactor output control signal.

Abstract: The present invention relates to an apparatus for efficiently and economically generating a cooling medium by using high-temperature and high-pressure steam generated in a nuclear power plant, and cooling method therefor. According to one embodiment of the present invention, the cooling medium generating apparatus provided in a containment vessel of a nuclear power generation facility so as to generate the cooling medium can comprise: a nuclear reactor for heating a coolant by using heat included in the heated coolant; a cooling module for generating the cooling medium by using the steam generated in the steam generator; and a cooling medium supplying pipe of which the end portion is connected to the outside of the containment vessel so as to supply the cooling medium, having been generated in the cooling module, to the outside of the containment vessel.

Abstract: A cooling apparatus of vehicle driving apparatuses of the invention controls flow of cooling water so as to cool engine cooling water by at least two radiators when a requested ability of cooling an internal combustion engine, is equal to or larger than a requested ability of cooling a hybrid device. The number of the radiators used for cooling the engine cooling water is larger than the number of the remaining radiator(s). The cooling apparatus controls the flow of the cooling water so as to cool device cooling water at least two radiators when the requested ability of cooling the hybrid device, is larger than the requested ability of cooling the internal combustion engine. The number of the radiators used for cooling the device cooling water is larger than the number of the remaining radiator(s).

Abstract: A method for controlling decentralized power generation plants comprises the steps of receiving control commands and/or measuring supply network parameters, processing the received control commands and/or the measured supply network parameters, generating control signals in response to the received control commands and/or the measured supply network parameters for controlling a first power inverter, transmitting the generated control signals to an inverter interface for being output to a first power inverter, adjusting plant parameters, for example the power output of the decentralized power generation plant using the first power inverter in response to the control signals received from the inverter interface. A power generation plant including a power generation plant controller for performing the method is also disclosed.

Abstract: Provided are a method and system for improving control of a steam generator level for preventing oscillation of the steam generator level in a nuclear power plant. In order to prevent oscillation of a steam generator level and resultant shutdown of a nuclear reactor, which may be caused when a high-level priority control function is frequently and repeatedly turned on/off as the steam generator level is excessively increased, by improving a feedwater control system in the nuclear power plant, a proportional integral control value may be controlled to be reduced, and thus, output while a certain condition is met after a high-level priority mode is deactivated or a signal instructing to enter the high-level priority control mode may be controlled not to be output.

Abstract: Methods and devices for active control for two-phase cooling include a cooling volume that has cavities and active coolant flow controls in the cavities configured to adjust coolant flow through the cavities. A reservoir in fluid communication with the cavities and there is a two-phase coolant in the reservoir and cavities. The two-phase coolant has a phase transition temperature between an ambient temperature and an expected device temperature. A coolant sensor is configured to determine a coolant phase condition in the cavities. A control module is configured to adjust the active coolant flow controls in response to the determined coolant phase condition.

Abstract: Provided is a method of the simulation construction for measurement of the control rod insertion time including a three-dimensional modeling operation of an inside wall of the nuclear reactor, a control rod, etc; a flow field configuration operation wherein the flow field is differentially configured by a variable grid system comprising variable cells which change the configuration and by an aligned grid system comprising fixed cells which maintains the configuration; a calculation operation of simulation estimated value for the insertion time by analyzing the thermal-hydraulic phenomenon using the three-dimensional CFD; and a cell change operation, wherein an error between the estimated value and the actual value is verified whether the error lies within the reference range, and, when the error exceeds the reference range, the size of the variable cell and/or of the size of the fixed cell is changed.

Abstract: A power module assembly includes a reactor core immersed in a coolant and a reactor vessel housing the coolant and the reactor core. An internal dry containment vessel submerged in liquid substantially surrounds the reactor vessel in a gaseous environment. During an over-pressurization event the reactor vessel is configured to release the coolant into the containment vessel and remove a decay heat of the reactor core through condensation of the coolant on an inner surface of the containment vessel.

Abstract: A nuclear power plant comprises a pressurized water reactor (PWR) and a steam generator driving a turbine driving an electric generator. A condenser condenses steam after flowing through the turbine. Responsive to a station blackout, the nuclear power plant is electrically isolated and a bypass valve is opened to convey bypass steam flow from the steam generator to the condenser without flowing through the turbine. The thermal power output of the PWR is gradually reduced over the transition time interval. After opening, the bypass valve is gradually closed over the transition time interval. A supplemental bypass valve may also be opened responsive to the station blackout to convey supplemental bypass steam flow from the steam generator to a feedwater system supplying secondary coolant feedwater to the steam generator. The supplemental bypass steam flow does not flow through the turbine and does not flow through the condenser.

Abstract: Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.

Abstract: An upper hole 37A and a lower hole 37B are provided at two positions, namely, upper and lower portions, of a side surface of a guide tube 27, and a thimble tube 22 is pressed against an inner circumferential surface of the guide tube 27, by a differential pressure between coolant inside and outside the upper hole 37A and the lower hole 37B.

Abstract: A nuclear reactor includes a reactor vessel, a containment vessel that surrounds the reactor vessel, and a condenser that receives coolant from within the reactor vessel. The containment vessel and the condenser are at least partially submerged within a common reactor pool of liquid.

Abstract: According to an embodiment, a pressurized water reactor plant has a primary system which includes: a reactor vessel for housing a reactor core which is cooled by a primary coolant, a single steam generator, a hot leg pipe for connecting the reactor vessel and the steam generator, cold leg pipes, at least two primary coolant pumps, and a pressurizer for pressurizing the primary coolant pressure boundary in which the primary coolant flows. The plant also has: a passive cooling and depressurization system which is a primary depressurization means for equalizing the primary system pressure to the secondary system pressure at the time of a tube rupture accident of the steam generator, and a reactor containment vessel containing the primary system and cooling the primary system by air cooling. Thus, a compact pressurized water rector with high economic efficiency, safety, and reliability can be provided.

Abstract: A system and a method of transforming a gain and an integral time constant of a proportional-integral (PI) controller according to a timer lapse time to relieve an excessive phenomenon of a steam generator level caused by rapid changes in open degrees of a downcomer feed-water valve and an economizer feed-water valve when reactor power transfers between low and high power sections. Accordingly, an excessive phenomenon of a steam generator level is relieved at a transfer time when reactor power transfers between low and high power sections. Therefore, a possibility of a stop of a reactor caused by the excessive phenomenon of the steam generator level is reduced to relieve burden on an operator and improve an operation rate and economic feasibility of a nuclear power plant.

Abstract: A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) may include a heating subsystem for heating feedwater flowing into an annulus of the NCBWR to increase the temperature of recirculation water flowing through the core above a predetermined recirculation water operating temperature. Additionally the system may include a temperature sensor operable to sense the temperature of the feedwater flowing into the annulus. The temperature sensor is communicatively connected to a temperature controller operable to command the heating subsystem to increase the temperature of the feedwater flowing into the annulus to a requested temperature above a predetermined operating temperature of the feedwater flowing into the annulus.

Abstract: A radiation exposure reduction method includes the steps of: injecting iron into a coolant which flows from the reactor cooling system to the reactor core in a nuclear power plant; and ferritizing and fixing radionuclides or parent nuclides thereof, which are contained in the coolant, on the surface of a reactor core structure, wherein an iron citrate which is soluble organic iron, or iron oxalate or iron fumarate which has a particle diameter of 3 ?m or less, is used as the iron to be injected into the coolant.

Abstract: Systems and methods for providing override control for a feedwater pump recirculation valve are provided. According to one embodiment, a system may include a controller and a processor communicatively coupled to the controller. The processor may be configured to receive one or more measurements associated with pump motor power driving feedwater pump flow. The feedwater pump recirculation valve may be configured to maintain a predetermined minimum recirculation flow through the feedwater pump by regulating recirculation pump flow through a recirculation line. The processor may be also configured to calculate, based at least in part on the one or more measurements, the recirculation pump flow, and compare the recirculation pump flow to the predetermined minimum recirculation flow. Based at least in part on the comparing, the processor may selectively provide an override control signal to the feedwater pump recirculation valve to selectively modify the recirculation pump flow.

Abstract: Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.

Abstract: A pressurized water reactor (PWR) comprises a pressure vessel, a reactor core disposed in the pressure vessel, an integral or external pressurizer, primary coolant disposed in the pressure vessel and heated by operation of the reactor core, and a steam generator disposed in the pressure vessel and configured to convert secondary coolant in the form of feedwater into steam by heat transfer from the primary coolant heated by operation of the reactor core to secondary coolant in the steam generator. A controller is configured to perform a PWR control method including the operations of (i) adjusting one or more parameters of the PWR and (ii) adjusting a pressurizer water level setpoint based on a predicted direction and magnitude of change of a pressurizer water level of the PWR predicted to result from the adjusting (i).

Abstract: Nuclear reactor systems and methods are described having many unique features tailored to address the special conditions and needs of emerging markets. The fast neutron spectrum nuclear reactor system may include a reactor having a reactor tank. A reactor core may be located within the reactor tank. The reactor core may include a fuel column of metal or cermet fuel using liquid sodium as a heat transfer medium. A pump may circulate the liquid sodium through a heat exchanger. The system may include a balance of plant with no nuclear safety function. The reactor may be modular, and may produce approximately 100 MWe.

Abstract: Illustrative embodiments provide systems, methods, apparatuses, and applications related to annealing nuclear fission reactor materials.

Abstract: A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is disclosed. The system, in accordance with an example embodiment of the present invention, may include a controller configured to control a power output level of the NCBWR by controlling a heating subsystem to adjust a temperature of feedwater flowing into an annulus of the NCBWR. The heating subsystem may include a steam diversion line configured to receive steam generated by a core of the NCBWR and a steam bypass valve configured to receive commands from the controller to control a flow of the steam in the steam diversion line, wherein the steam received by the steam diversion line has not passed through a turbine. Additional embodiments of the invention may include a feedwater bypass valve for controlling an amount of flow of the feedwater through a heater bypass line to the annulus.

Abstract: A flow limiter may include a head and a fin extending from a bottom of the head. The head may include a side surface having at least one first hole and the side surface may be symmetric about a first axis. The fin may include at least one second hole and the at least one second hole may have an axis substantially perpendicular to the first axis. The flow limiter may be inserted into a support casting that may interface with a nuclear fuel bundle to reduce the flow of water to the nuclear fuel bundle thereby reducing a moisture carry over (MCO) level at an exit of a fuel bundle of a nuclear reactor.

Abstract: The invention relates to a nuclear reactor primary circuit comprising a primary pipeline (30), which defines an internal volume (32) and in which a primary nuclear reactor coolant downwardly runs, an additional pipeline (26) which is branched to the primary pipeline (30) and defines an internal volume communicating with the internal volume (32) of the primary pipeline (30) and a cuff (36) whose first end (50) is connected to the additional pipeline (26) and the second free end (52) is positioned in the internal volume (32) of the primary pipeline (30). According to said invention, the second end (52) is delimited by a free peripherial edge (53) comprising at least one upstream and downstream sections (56, 58) which are oriented towards the upstream, wherein the upstream section (56) penetrates into the internal volume (32) deeper from the primary pipeline (30) than the downstream section (58).

Abstract: A pressurized water nuclear reactor (PWR) has an internal pressurizer volume containing a steam bubble and is surrounded by a containment structure. A condenser is disposed inside the containment structure and is operatively connected with an external heat sink disposed outside of the containment structure. A valve assembly operatively connects the PWR with the condenser responsive to an abnormal operation signal such that the condenser condenses steam from the steam bubble while rejecting heat to the external heat sink and returns the condensed water to the PWR. A quench tank contains water with dissolved neutron poison. A valved tank pressurizing path selectively connects the steam bubble to the quench tank to pressurize the quench tank, and a valved soluble poison delivery path selectively connects the quench tank to the PWR such that the quench tank under pressure from the steam bubble discharges water with dissolved neutron poison into the PWR.

Abstract: A boiling water reactor has a core disposed in the reactor pressure vessel and loaded with a plurality of fuel assemblies including transuranic nuclides. A ratio of Pu-239 in all of the transuranic nuclides included in the fuel assembly, which is loaded in the core, with a burnup of 0 is 3% or more but 45% or less. In the fuel assembly having a channel box and a plurality of fuel rods disposed in the channel box, a transverse cross section of a fuel pellet in the fuel rod occupies 30% or more but 55% or less of a transverse cross section of a unit fuel rod lattice in the channel box.

Abstract: A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

Abstract: Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.

Abstract: Illustrative embodiments provide systems, methods, apparatuses, and applications related to annealing nuclear fission reactor materials.

Abstract: A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

Abstract: In the present invention, a reactor power control apparatus of a natural circulation reactor comprises a power control apparatus for controlling reactor power and a pressure control apparatus for controlling reactor pressure. A power adjustment demand signal S4 is input from the power control apparatus into the pressure control apparatus. The pressure control apparatus controls degree of opening of a inlet port steam control valve provided in a moisture separation heater that is connected to a low-pressure turbine, based on the power adjustment demand signal S4. A reactor power control apparatus of the natural circulation reactor can suppress reactor power variation and obtain stable power.

Abstract: In implementing an induction heating stress improvement (IHSI) method in a nuclear plant, cooling characteristic with respect to the inner surface of piping is improved by appropriate structure/layout of nozzles, and further, the cooling effect when applying IHSI to a real machine is verified by installing a thermometer, as well as air in the portion subjected to IHSI is removed by heating the piping prior to the execution of IHSI.

Abstract: A method of operating a nuclear reactor is disclosed. The reactor (1) encloses a core having a plurality of fuel rods (9). Each fuel rod (9) includes a cladding and fuel pellets of a nuclear fuel. The fuel pellets are arranged in an inner space of the cladding leaving a free volume comprising an upper plenum, a lower plenum and a pellet-cladding gap. The reactor is operated at a normal power and a normal inlet sub-cooling during a normal state. The reactor is monitored for detecting a defect on the cladding of any of the fuel rods. The operation of the reactor is changed to a particular state after detecting such a defect. The particular state permits an increase of the free volume in the defect fuel rod. The reactor is operated at the particular state during a limited time period, after which the reactor is operated at the normal state.

Abstract: The feedwater controller of a nuclear power plant having three or more feedwater pumps supplying water to the reactor vessel, electric motors driving the feedwater pumps and electric power converters connected to the electric motors is equipped with a flow rate controller and a trip compensation means. The flow rate controller calculates a flow rate to the reactor vessel based on a detected value indicating a condition of the nuclear power plant and a preset value of the water level of the reactor vessel, and generates a rotation speed command signal for the electric motors based on the flow rate command signal. The trip compensation means increases the rotation speed of the electric motors not having tripped if one of the feedwater pumps trips.

Abstract: In a control system for a plant controlling a plant such as a nuclear power plant 1 with use of a plurality of digital control devices 41, the plurality of digital control devices 41 include a plurality of control functions 46 to 56, and the plurality of control functions 46 to 56 are provided in the plurality of digital control devices 41 in a distributed manner so that the digital control devices 41 may not fall below safety standards preset by safety analyses. This provides a control system for a plant using the plurality of digital control devices 41 and configured to control a plant safely even when a digital control device is failed.

Abstract: Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.

Abstract: Disclosed embodiments include electromagnetic flow regulators for regulating flow of an electrically conductive fluid, systems for regulating flow of an electrically conductive fluid, methods of regulating flow of an electrically conductive fluid, nuclear fission reactors, systems for regulating flow of an electrically conductive reactor coolant, and methods of regulating flow of an electrically conductive reactor coolant in a nuclear fission reactor.

Abstract: The present invention is directed to a cooling system for removing heat from a Fischer-Tropsch (F-T) slurry reactor. The cooling system including at least one downcomer having an upper portion, a lower portion, and a diameter; the at least one downcomer disposed within the F-T reactor to deliver a coolant downward through the F-T reactor at a predetermined velocity, the at least one downcomer extending a length within the F-T reactor wherein the coolant is introduced into the upper portion of the at least one downcomer in a substantially liquid phase; the diameter of the at least one downcomer and the pressure of the introduced coolant cooperate to increase the coolant velocity thereby generating backpressure in the at least one downcomer to maintain the coolant in the substantially liquid phase along the length of the at least one downcomer.

Abstract: A nuclear fission reactor, flow control assembly, methods therefor and a flow control assembly system. The flow control assembly is coupled to a nuclear fission module capable of producing a traveling burn wave at a location relative to the nuclear fission module. The flow control assembly controls flow of a fluid in response to the location relative to the nuclear fission module. The flow control assembly comprises a flow regulator subassembly configured to be operated according to an operating parameter associated with the nuclear fission module. In addition, the flow regulator subassembly is reconfigurable according to a predetermined input to the flow regulator subassembly. Moreover, the flow control assembly comprises a carriage subassembly coupled to the flow regulator subassembly for adjusting the flow regulator subassembly to vary fluid flow into the nuclear fission module.

Abstract: A nuclear reactor includes a reactor vessel, a containment vessel that surrounds the reactor vessel, and a condenser that receives coolant from within the reactor vessel. The containment vessel and the condenser are at least partially submerged within a common reactor pool of liquid.

Abstract: An in situ heat treatment system for producing hydrocarbons from a subsurface formation includes a plurality of wellbores in the formation. At least one heater is positioned in at least two of the wellbores. A self-regulating nuclear reactor provides energy to at least one of the heaters to heat the temperature of the formation to temperatures that allow for hydrocarbon production from the formation. A temperature of the self-regulating nuclear reactor is controlled by controlling a pressure of hydrogen supplied to the self-regulating nuclear reactor, and wherein the pressure is regulated based upon formation conditions.

Abstract: A system and a method of transforming a gain and an integral time constant of a proportional-integral (PI) controller according to a timer lapse time to relieve an excessive phenomenon of a steam generator level caused by rapid changes in open degrees of a downcomer feed-water valve and an economizer feed-water valve when reactor power transfers between low and high power sections. Accordingly, an excessive phenomenon of a steam generator level is relieved at a transfer time when reactor power transfers between low and high power sections. Therefore, a possibility of a stop of a reactor caused by the excessive phenomenon of the steam generator level is reduced to relieve burden on an operator and improve an operation rate and economic feasibility of a nuclear power plant.

Abstract: In a nuclear reactor core, a lower tie plate assembly is provided with asymmetric features designed to control or vary a loss coefficient as a function of rotation of the associated fuel assembly. An associated method is provided to control the flow of coolant through the associated fuel assembly via rotation of the fuel assembly relative to the fuel support member. Control of the flow can be used to adjust assembly flow rate, assembly power and flow quality within the fuel assembly, among other assembly operational characteristics. Such flow control will impact the flow through other assemblies as well, since core flow remains generally fixed. On a core-wide basis, such flow control can be used to optimize core wide parameters. Optimization parameters of particular interest are the fuel cycle cost and moisture carryover.

Abstract: A pressurized water reactor (PWR) comprises a pressure vessel, a reactor core disposed in the pressure vessel, an integral or external pressurizer, primary coolant disposed in the pressure vessel and heated by operation of the reactor core, and a steam generator disposed in the pressure vessel and configured to convert secondary coolant in the form of feedwater into steam by heat transfer from the primary coolant heated by operation of the reactor core to secondary coolant in the steam generator. A controller is configured to perform a PWR control method including the operations of (i) adjusting one or more parameters of the PWR and (ii) adjusting a pressurizer water level setpoint based on a predicted direction and magnitude of change of a pressurizer water level of the PWR predicted to result from the adjusting (i).