Abstract: An apparatus including an integrated system, which can include a nuclear reactor; and a containment isolation system configured to prevent release of radioactive material from the nuclear reactor. The containment isolation system can include a containment vessel and a containment isolation test valve. The containment isolation test valve can include a body having a first test port and a first test port plug. The containment isolation test valve can include a cover configured to couple with the body, the cover having, a first seal, a second seal, an area between the first seal and the second seal, a second test port, and a second test port plug. The containment isolation system can include a containment isolation valve.

Abstract: Integrated energy systems, such as for use in enhanced oil recovery operations, and associated devices and methods are described herein. A representative integrated energy system can include a power plant system having multiple modular nuclear reactors. The nuclear reactors can generate steam for direct industrial use or for use in an electrical power conversion system to generate electricity. Individual ones of the nuclear reactors can be configured to generate steam or electricity based on the requirements of different stages of the oil recovery operation. For example, during a first stage, a subset of the nuclear reactors can be configured to generate steam for the oil recovery operation for injection into an oil reservoir. During a second stage, some or all of the nuclear reactors in the subset can be reconfigured to generate electricity that can be routed to an industrial process different than the oil recovery operation.

Abstract: A system includes a containment vessel configured to prohibit a release of a coolant, and a reactor vessel mounted inside the containment vessel. An outer surface of the reactor vessel is exposed to below atmospheric pressure, wherein substantially all gases are evacuated from the containment vessel.

Abstract: A reactor vessel that includes a reactor core mounted within a volume of the reactor vessel, the reactor core comprising one or more nuclear fuel assemblies configured to generate a nuclear fission reaction, a riser positioned above the reactor core, the riser forming a primary coolant flow path, a steam generator thermally coupled to the riser, the steam generator communicatively coupled to a steam turbine through a steam inlet that includes a steam inlet valve, a secondary coolant flow path that extends through the steam generator, the secondary coolant flow path coupled to a coolant pump, and a control system coupled to both the steam inlet valve and the coolant pump, the control system configured to control a power output of the nuclear fission reaction by adjusting one or more parameters of the steam inlet valve or the coolant pump.

Abstract: An integrated system for indirect cycle steam heating comprising a nuclear power module configured to output first steam; a turbine generator configured to receive the first steam and output second steam; a heat exchanger configured to receive water, receive at least one of first steam, second steam, and transfer heat from the at least one of first steam and second steam into the water to create third steam a peaking heater configured to receive the third steam, transfer augmenting heat into the third steam, and heat, based at least in part on the transfer, the third steam to have a temperature above a threshold temperature an auxiliary heater configured to receive the third steam; and a chemical processing plant configured to receive the third steam and transfer heat from the third steam into a chemical.

Abstract: A nuclear power system includes a reactor vessel that includes a reactor core mounted therein. The reactor core includes nuclear fuel assemblies configured to generate a nuclear fission reaction. The nuclear power system further includes a chemical injection system configured to inject a chemical into the reactor vessel and remove the chemical from the reactor vessel, and a control system communicably coupled to the chemical injection system and configured to control a power output of the nuclear fission reaction. For example, the control system can determine that the power output is greater than an upper value of a range or less than a lower value of the range and, based on the determination, adjust an amount of the chemical injected into or removed from the reactor vessel by the chemical injection system to adjust the power output.

Abstract: A nuclear reactor module, comprising a reactor pressure vessel including a removably attached lower reactor vessel head configured to house a reactor core; a lower reactor vessel head removably attached to the reactor pressure vessel and configured to house the reactor core; a containment vessel encapsulating the reactor pressure vessel; and a lower containment head removably attached to the containment vessel and configured to house the lower reactor vessel head, the containment vessel and the reactor pressure vessel being configured to be lifted and transported between a reactor bay and a refueling bay within a nuclear reactor building via a crane.

Abstract: Power generation systems, such as nuclear power generation systems, are described herein. A representative power generation system includes a heat source, a heat pipe, and a thermophotovoltaic cell. The heat pipe includes a first region and a second region. The first region is positioned to absorb heat from the heat source, and the second region is positioned to radiate at least a portion of the absorbed heat away from the heat pipe as thermal radiation. The thermophotovoltaic cell is positioned to receive the thermal radiation from the second region of the heat pipe and to convert at least a portion of the thermal radiation to electrical energy. The power generation system can further include another heat pipe positioned to remove waste heat from the thermophotovoltaic cell.

Abstract: Supports with integrated sensors for nuclear reactor steam generators, and associated systems and methods, are disclosed. A representative method for forming a nuclear-powered steam generator includes forming an instrumented support, the instrumented support including a carrier portion and a retainer portion, with at least one of the carrier portion or the retainer portion being integrally formed with a sensor via an additive manufacturing process. The method can further include coupling the sensor to a communication link, supporting a helical steam conduit on the instrumented support, and installing the helical steam conduit and the instrumented support in a nuclear reactor. The helical steam conduit is positioned along a primary flow path, which is in turn positioned to circulate a heated primary flow in thermal communication with the helical steam conduit.

Abstract: A thermal control system for a reactor pressure vessel comprises a plate having a substantially circular shape that is attached to a wall of the reactor pressure vessel. The plate divides the reactor pressure vessel into an upper reactor pressure vessel region and a lower reactor pressure vessel region. Additionally, the plate is configured to provide a thermal barrier between a pressurized volume located within the upper reactor pressure vessel region and primary coolant located within the lower reactor pressure vessel region. One or more plenums provide a passageway for a plurality of heat transfer tubes to pass fluid through the wall of the reactor pressure vessel. The plurality of heat transfer tubes are connected to the plate.

Abstract: A nuclear power system includes a reactor vessel that includes a reactor core that includes nuclear fuel assemblies configured to generate a nuclear fission reaction. A representative nuclear power system further includes a riser positioned above there actor core and a primary coolant flow path that extends from a bottom portion of the reactor vessel, through the reactor core, and through an annulus between the riser and the reactor vessel. A primary coolant circulates through the primary coolant flow path to receive heat from the nuclear fission reaction and release the heat to a power generation system configured to generate electric power. The nuclear power system further includes a control rod assembly system positioned in the reactor vessel and configured to position control rods in only two discrete positions.

Abstract: An in-core instrumentation system for a reactor module includes a plurality of in-core instruments connected to a containment vessel and a reactor pressure vessel at least partially located within the containment vessel. A reactor core is housed within a lower head that is removably attached to the reactor pressure vessel, and lower ends of the in-core instruments are located within the reactor core. The in-core instruments are configured such that the lower ends are concurrently removed from the reactor core as a result of removing the lower head from the reactor pressure vessel.

Abstract: A nuclear reactor protection system includes a plurality of functionally independent modules, each of the modules configured to receive a plurality of inputs from a nuclear reactor safety system, and logically determine a safety action based at least in part on the plurality of inputs, each of the functionally independent modules comprising a digital module or a combination digital and analog module, an analog module electrically coupled to one or more of the functionally independent modules, and one or more nuclear reactor safety actuators communicably coupled to the plurality of functionally independent modules to receive the safety action determination based at least in part on the plurality of inputs.

Abstract: A power module assembly may include a reactor vessel containing a primary coolant and one or more inlets configured to draw a secondary coolant from the containment cooling pool in response to a loss of power and/or a loss of coolant. One or more outlets may be submerged in the containment cooling pool and may be configured to vent the secondary coolant into the containment cooling pool. A heat exchanger may be configured to remove heat from the primary coolant, wherein the heat may be removed by circulating the secondary coolant from the containment cooling pool through the heat exchanger via natural circulation.

Abstract: A nuclear reactor protection system includes a plurality of functionally independent modules, each of the modules configured to receive a plurality of inputs from a nuclear reactor safety system, and logically determine a safety action based at least in part on the plurality of inputs; and one or more nuclear reactor safety actuators communicably coupled to the plurality of functionally independent modules to receive the safety action determination based at least in part on the plurality of inputs.

Abstract: Nuclear reactor systems and associated devices and methods are described herein. A representative nuclear reactor system includes a heat pipe network having an evaporator region, an adiabatic region, and a condenser region. The heat pipe network can define a plurality of flow paths having an increasing cross-sectional flow area in a direction from the evaporator region toward the condenser region. The system can further include nuclear fuel thermally coupled to at least a portion of the evaporator region. The heat pipe network is positioned to transfer heat received from the fuel at the evaporator region, to the condenser region. The system can further include one or more heat exchangers thermally coupled to the evaporator region for transporting the heat out of the system for use in one or more processes, such as generating electricity.

Abstract: Nuclear reactor systems and associated devices and methods are described herein. A representative nuclear reactor system includes a reactor vessel having a barrier separating a core region from a shield region. A plurality of fuel rods containing a liquid nuclear fuel are positioned in the core region. A liquid moderator material is also positioned in the core region at least partially around the fuel rods. A plurality of heat exchangers can be positioned in the shield region, and a plurality of heat pipes can extend through the barrier. The moderator material is positioned to transfer heat received from the liquid nuclear fuel to the heat pipes, and the heat pipes are positioned to transfer heat received from the moderator material to the heat exchangers. The heat exchangers can transport the heat out of the system for use in one or more processes, such as generating electricity.

Abstract: A system for servicing a nuclear reactor module comprises a crane operable to attach to the nuclear reactor module, wherein the crane includes provisions for routing signals from one or more sensors of the nuclear reactor module to one or more sensor receivers.

Abstract: A damping area or “dash pot” on the upper ends of control rods absorb energy from dropped control rod assemblies without narrowing the diameter of guide tubes. As a result, coolant can freely flow through the guide tubes reducing boiling water issues. The dampening area reduces a separation distance between an outside surface of the control rod and an inside surface of the guide tubes decelerating the control rods when entering a top end of the guide tubes. In another example, the dampening area may be located on a drive shaft. The dampening area may have a larger diameter than an opening in a drive shaft support member that decelerates the drive shaft when dropped by a drive mechanism.

Abstract: A system includes a containment vessel configured to prohibit a release of a coolant, and a reactor vessel mounted inside the containment vessel. An outer surface of the reactor vessel is exposed to below atmospheric pressure, wherein substantially all gases are evacuated from within the containment vessel.