A sensor system for a fuel rod including a fuel pellet stack, the sensor system including a wireless interrogator disposed outside the fuel rod and a passive sensor component disposed within the fuel rod. The passive sensor component includes a receiver structured to receive an interrogation signal and output an excitation signal in response to receiving the interrogation signal, a reference transmitter structured to output a reference signal to the reference receiver in response to the excitation signal, a sensing transmitter structured to output a sensing signal to the sensing receiver in response to the excitation signal, and a core at least partially disposed within the sensing transmitter and coupled to move in conjunction with expansion or contraction of the fuel pellet stack, to move based on changes in pressure within the fuel rod, or to change temperature based on temperature changes within the fuel rod.

Plurality of layers form a nuclear fission reactor structure, each layer having an inner segment body, an intermediate segment body, and an outer segment body (each segment body separated by an interface). The layers include a plurality of cladding arms having involute curve shapes that spirally radiate outward from a radially inner end to a radially outer end. Chambers in the involute curve shaped cladding arm contain fuel compositions (and/or other materials such as moderators and poisons). The design of the involute curve shaped cladding arms and the composition of the materials conform to neutronic and thermal management requirements for the nuclear fission reactor and are of sufficiently common design and/or have sufficiently few variations as to reduce manufacturing complexity and manufacturing variability.

Various embodiments of a transportable nuclear power generator having a plurality of subcritical power modules are disclosed. Each of the plurality of subcritical power modules includes a fuel cartridge, a power conversion unit, and a housing substantially enclosing the fuel cartridge and the power conversion unit. The fuel cartridge contains a nuclear fuel and has a proximal end and a distal end. The power conversion unit includes a compressor turbine disposed at the proximal end of the fuel cartridge and a power turbine disposed at the distal end of the fuel cartridge. At least one of the plurality of subcritical power modules is movable with respect to the other of the plurality of subcritical power modules between a first position and a second position to control criticality of the nuclear fuel contained in the fuel cartridges of the plurality of subcritical power modules.

Reactor core and thermal neutron fission reactor has fuel rods with a composite fuel composition (each having the same uniform cross-section along their axial length), end plates at first and second ends, and intermediate support plates located along a longitudinal length of the reactor core. In a radial cross-section, the fuel rods are arranged at nodes of a hexagonal pitch arrangement, in which the nodes are in a spaced-apart arrangement and interconnected by ligaments. Openings between the nodes form part of a coolant flow path through the thermal neutron reactor core. At least two of the nodes of the hexagonal pitch arrangement are sized to allow insertion, translation, removal, or a combination thereof of auxiliary equipment, such as a target delivery system (TDS) for isotopes. Thermal neutron flux (neutrons ≤0.06 eV) is maximized for maximum neutron activation potential, which is applied to produce both commercial and research isotopes.

A sensor system for a fuel rod including a fuel pellet stack, the sensor system including a wireless interrogator disposed outside the fuel rod and a passive sensor component disposed within the fuel rod. The passive sensor component includes a receiver structured to receive an interrogation signal and output an excitation signal in response to receiving the interrogation signal, a reference transmitter structured to output a reference signal to the reference receiver in response to the excitation signal, a sensing transmitter structured to output a sensing signal to the sensing receiver in response to the excitation signal, and a core at least partially disposed within the sensing transmitter and coupled to move in conjunction with expansion or contraction of the fuel pellet stack, to move based on changes in pressure within the fuel rod, or to change temperature based on temperature changes within the fuel rod.

A sensor system for a fuel rod including a fuel pellet stack, the sensor system including a wireless interrogator disposed outside the fuel rod and a passive sensor component disposed within the fuel rod. The passive sensor component includes a receiver structured to receive an interrogation signal and output an excitation signal in response to receiving the interrogation signal, a reference transmitter structured to output a reference signal to the reference receiver in response to the excitation signal, a sensing transmitter structured to output a sensing signal to the sensing receiver in response to the excitation signal, and a core at least partially disposed within the sensing transmitter and coupled to move in conjunction with expansion or contraction of the fuel pellet stack, to move based on changes in pressure within the fuel rod, or to change temperature based on temperature changes within the fuel rod.

A detection apparatus includes a resonant electrical circuit supported within an interior of a nuclear fuel rod generates a response pulse in response to an excitation pure and transmits the response pulse through a cladding of the fuel rod to another location within a reactor in which the fuel rod is housed and without any breach in the cladding. A characteristic of the response pulse is indicative of a condition of the fuel rod. The detection apparatus also includes a transmitter positioned outside the cladding, in the reactor, in the vicinity of the fuel rod and configured to generate the excitation pulse and transmit the excitation pulse through the cladding to the resonant electrical circuit. A receiver is supported within the reactor outside of the cladding and, in response to the response pulse, communicates a signal to an electronic processing apparatus outside of the reactor.

A detection apparatus includes a resonant electrical circuit supported within an interior of a nuclear fuel rod generates a response pulse in response to an excitation pure and transmits the response pulse through a cladding of the fuel rod to another location within a reactor in which the fuel rod is housed and without any breach in the cladding. A characteristic of the response pulse is indicative of a condition of the fuel rod. The detection apparatus also includes a transmitter positioned outside the cladding, in the reactor, in the vicinity of the fuel rod and configured to generate the excitation pulse and transmit the excitation pulse through the cladding to the resonant electrical circuit. A receiver is supported within the reactor outside of the cladding and, in response to the response pulse, communicates a signal to an electronic processing apparatus outside of the reactor.

A detection apparatus includes a resonant electrical circuit supported within an interior of a nuclear fuel rod generates a response pulse in response to an excitation pulse and transmits the response pulse through a cladding of the fuel rod to another location within a reactor in which the fuel rod is housed and without any breach in the cladding. A characteristic of the response pulse is indicative of a condition of the fuel rod. The detection apparatus also includes a transmitter positioned outside the cladding, in the reactor, in the vicinity of the fuel rod and configured to generate the excitation pulse and transmit the excitation pulse through the cladding to the resonant electrical circuit. A receiver is supported within the reactor outside of the cladding and, in response to the response pulse, communicates a signal to an electronic processing apparatus outside of the reactor.

A detection apparatus includes a resonant electrical circuit supported within an interior of a nuclear fuel rod generates a response pulse in response to an excitation pulse and transmits the response pulse through a cladding of the fuel rod to another location within a reactor in which the fuel rod is housed and without any breach in the cladding. A characteristic of the response pulse is indicative of a condition of the fuel rod. The detection apparatus also includes a transmitter positioned outside the cladding, in the reactor, in the vicinity of the fuel rod and configured to generate the excitation pulse and transmit the excitation pulse through the cladding to the resonant electrical circuit. A receiver is supported within the reactor outside of the cladding and, in response to the response pulse, communicates a signal to an electronic processing apparatus outside of the reactor.