An integral pressurized water reactor (PWR) comprises: a cylindrical pressure vessel including an upper vessel section and a lower vessel section joined by a mid-flange; a cylindrical central riser disposed concentrically inside the cylindrical pressure vessel and including an upper riser section disposed in the upper vessel section and a lower riser section disposed in the lower vessel section; steam generators disposed inside the cylindrical pressure vessel in the upper vessel section; a reactor core comprising fissile material disposed inside the cylindrical pressure vessel in the lower vessel section; and control rod drive mechanism (CRDM) units disposed inside the cylindrical pressure vessel above the reactor core and in the lower vessel section. There is no vertical overlap between the steam generators and the CRDM units.

Disclosed is an apparatus, system, and method for monitoring a position of a control rod disposed in a nuclear reactor vessel in a radioactive environment. A data processing unit located outside a containment structure includes a processor and a memory storing executable instructions. A nuclear reactor vessel includes a plurality of control rods proximate to the control rod and a coil stack of a plurality of control rod position indicator coils. A data cabinet mounted on the nuclear reactor vessel head inside the containment structure includes an analog multiplexer and a communication circuit. The processor executes the instructions to select a control rod position indicator coil through the analog multiplexer, pass a signal from the control rod position indicator coil through the analog multiplexer, receive the signal from the analog multiplexer through the communication circuit, and determine a position of the control rod based on the received signal.

Disclosed is an apparatus, system, and method for monitoring a position of a control rod disposed in a nuclear reactor vessel in a radioactive environment. A data processing unit located outside a containment structure includes a processor and a memory storing executable instructions. A nuclear reactor vessel includes a plurality of control rods proximate to the control rod and a coil stack of a plurality of control rod position indicator coils. A data cabinet mounted on the nuclear reactor vessel head inside the containment structure includes an analog multiplexer and a communication circuit. The processor executes the instructions to select a control rod position indicator coil through the analog multiplexer, pass a signal from the control rod position indicator coil through the analog multiplexer, receive the signal from the analog multiplexer through the communication circuit, and determine a position of the control rod based on the received signal.

One variation of a method for deploying a nuclear reactor system includes: constructing a tunnel at a particular location; and installing the nuclear reactor, loaded with a first core assembly, within the tunnel. The method further includes, during an operating period: in response to detecting a high-energy demand period: triggering operation of the nuclear reactor at a first capacity, directing a first portion of energy output to a charging station for charging electric vehicles, and directing a second portion, less than the first portion, of energy output to a gas sequestration subsystem; and, in response to detecting a low-energy demand period, triggering operation of the nuclear reactor at a second capacity less than the first capacity, directing a third portion of energy, less than the first portion, output to the charging station, and directing a fourth portion of energy, exceeding the second portion, output to the gas sequestration subsystem.

A nuclear reactor is provided. The reactor includes a reactor pressure vessel housing plural fuel rods containing fissile material, the reactor pressure vessel having an upper, removable, vessel head. The reactor further includes control rods, each made of a neutron-absorbing material. The control rods are inserted into the reactor through the vessel head and between the fuel rods to control the rate of the fuel rods' fission reaction. The control rods are movable over a normal range of insertion positions relative to the vessel head to control the power output of the reactor when it is critical and generating useful power, and to put the reactor in a sub-critical shutdown state. The reactor further includes control rod drive mechanisms carried by the vessel head and operable to drive the movements of the control rods. The control rod drive mechanisms are controllable to release the control rods when a vessel opening operation is performed in which the reactor is in the shutdown state and the vessel head is lifted upwards from the reactor pressure vessel such that the control rods slide therethrough to remain stationary relative to the fuel rods to maintain the shutdown state. The reactor further has monitoring unit to identify whether a control rod is accidently lifting with the vessel head.

A power distribution plate (PDP) sits on top of a support plate. Control rod drive mechanism (CRDM) units are mounted on top of the PDP, but the PDP is incapable of supporting the weight of the CRDM units and instead transfers the load to a support plate. The PDP has receptacles which receive cable modules each including mineral insulated (MI) cables, the MI cables being connected with the CRDM units. The PDP may further include a set of hydraulic lines underlying the cable modules and connected with the CRDM units. The cable modules in their receptacles define conduits or raceways for their MI cables and for any underlying hydraulic lines.

A power distribution plate (PDP) sits on top of a support plate. Control rod drive mechanism (CRDM) units are mounted on top of the PDP, but the PDP is incapable of supporting the weight of the CRDM units and instead transfers the load to a support plate. The PDP has receptacles which receive cable modules each including mineral insulated (MI) cables, the MI cables being connected with the CRDM units. The PDP may further include a set of hydraulic lines underlying the cable modules and connected with the CRDM units. The cable modules in their receptacles define conduits or raceways for their MI cables and for any underlying hydraulic lines.

A method of dynamic control rod reactivity measurement for a reactor using a fission chamber as an out-of-reactor measuring instrument includes: maintaining the reactor in a critical state having a set output by inserting a reference control bank into a reactor core to a first depth; completely inserting the reference control bank into the reactor core from the first depth at a maximum allowable speed and immediately completely withdrawing the reference control bank from the reactor core at the maximum allowable speed, and measuring a first signal of the out-of-reactor measuring instrument from before the insertion of the reference control bank to after the withdrawal of the reference control bank; and determining static controllability of the reference control bank by adding residual controllability measurement value of the reactor to a first static reactivity of the reactor calculated using the first signal of the out-of-reactor measuring instrument.

A nuclear power system includes a reactor vessel that includes a reactor core mounted within a volume of the reactor vessel. The reactor core includes one or more nuclear fuel assemblies configured to generate a nuclear fission reaction. The nuclear power system further includes a containment vessel sized to enclose the reactor vessel such that an open volume is defined between the containment vessel and the reactor vessel. A boron injection system is positioned in the open volume of the containment vessel and includes an amount of boron sufficient to stop the nuclear fission reaction or maintain the nuclear fission reaction at a sub-critical state. The boron injection system is positioned to deliver the amount of boron into the open volume.

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 riser positioned above the reactor core; a primary coolant flow path that extends from a bottom portion of the volume through the reactor core and through an annulus between the riser and the reactor vessel; a primary coolant that circulates through the primary coolant flow path to receive heat from the nuclear fission reaction and release the heat to generate electric power in a power generation system; and a control rod assembly system positioned in the reactor vessel and configured to position control rods in only two discrete positions.