An in-core detector configured to measure a power distribution in a nuclear reactor is disclosed herein. The in-core detector includes a housing configured to be placed within a predetermined location of the nuclear reactor and a plurality of a gamma detectors. Each gamma detector of the plurality of gamma detectors includes a Schottky diode including an active semiconductor region and a Schottky contact, an Ohmic contact, a photoelectron source material configured to transfer electrons to the active region upon contact with gamma radiation, and a first and second lead. The plurality of gamma detectors are positioned within the housing such that each gamma detector of the plurality of gamma detectors is radially offset relative to an adjacent gamma detector of the plurality of gamma detectors, such that the first and second leads of each gamma detector are offset relative to the first and second leads of the adjacent gamma detector.

Disclosed is a method of measuring a number of environmental conditions with a transmitter device, said transmitter device comprising a neutron detector structured to generate electrical current from neutron flux, an oscillator circuit comprising an electrostatic switch electrically connected to said neutron detector, and an antenna electrically connected with said electrostatic switch, wherein said electrostatic switch is moveable based on said neutron detector, wherein said oscillator circuit is structured to pulse said antenna based on said neutron detector, wherein a period between pulses is related to the neutron flux, the method comprising the steps of: generating the electrical current with said neutron detector, storing energy in said oscillator circuit until a trigger voltage of said electrostatic switch is reached, and emitting a signal with said antenna corresponding to a number of characteristic values of said oscillator circuit.

Disclosed is a method of measuring a number of environmental conditions with a transmitter device, said transmitter device comprising a neutron detector structured to generate electrical current from neutron flux, an oscillator circuit comprising an electrostatic switch electrically connected to said neutron detector, and an antenna electrically connected with said electrostatic switch, wherein said electrostatic switch is moveable based on said neutron detector, wherein said oscillator circuit is structured to pulse said antenna based on said neutron detector, wherein a period between pulses is related to the neutron flux, the method comprising the steps of: generating the electrical current with said neutron detector, storing energy in said oscillator circuit until a trigger voltage of said electrostatic switch is reached, and emitting a signal with said antenna corresponding to a number of characteristic values of said oscillator circuit.

A temperature measurement sensor for use in a nuclear reactor is described. The sensor includes a first neutron detector member and a second neutron detector member. The first neutron detector includes an outer shield material with an effective neutron capture cross section that is temperature dependent. The first neutron detector member outputs a first current signal and the second neutron detector member outputs a second current signal. An electrical connection between the first and second neutron detector members produces a net current that is the difference in current between the first and second signals. The difference is proportional to changes in temperature.

A core performance calculation apparatus includes: a nuclear constant storage device that stores nuclear constants that have been evaluated in advance in analysis of a fuel assembly; and a three-dimensional core nuclear thermal-hydraulic characteristics analysis device that obtains core characteristics including a power of the fuel assembly. The nuclear constant storage device stores, as the nuclear constants, response relationships between a neutron that flows into a fuel assembly cell and fuel assembly nuclear characteristics, and response relationships between a neutron that is produced from a fuel rod and the fuel assembly nuclear characteristics. The three-dimensional core nuclear thermal-hydraulic characteristics analysis device obtains a neutron effective multiplication factor by using the response relationships that have been stored in the nuclear constant storage device, and obtains the power of the fuel assembly by using the neutron effective multiplication factor.

A core monitoring system including: a TIP measuring a neutron amount in a nuclear reactor; a TIP drive device; a TIP panel; a neutron monitoring panel; and a process computer. The TIP panel includes: a TIP level processor and a TIP position processor that process a TIP level signal and a TIP position signal input from the TIP drive device, respectively; a time setting section synchronizing the TIP level signal and the TIP position signal; and a TIP level data storage section storing synchronized TIP level data. The neutron monitoring panel includes a time setting section setting collecting time of a LPRM level signal and an APRM level signal. The process computer compares the time and stores the TIP level data from the TIP panel and the LPRM and APRM level signals from the neutron monitoring panel corresponding in time, and calculates core performance based on the TIP level data.

A core monitoring system including: a TIP measuring a neutron amount in a nuclear reactor; a TIP drive device; a TIP panel; a neutron monitoring panel; and a process computer. The TIP panel includes: a TIP level processor and a TIP position processor that process a TIP level signal and a TIP position signal input from the TIP drive device, respectively; a time setting section synchronizing the TIP level signal and the TIP position signal; and a TIP level data storage section storing synchronized TIP level data. The neutron monitoring panel includes a time setting section setting collecting time of a LPRM level signal and an APRM level signal. The process computer compares the time and stores the TIP level data from the TIP panel and the LPRM and APRM level signals from the neutron monitoring panel corresponding in time, and calculates core performance based on the TIP level data.

Illustrative embodiments provide methods and systems for migrating fuel assemblies in a nuclear fission reactor, methods of operating a nuclear fission traveling wave reactor, methods of controlling a nuclear fission traveling wave reactor, systems for controlling a nuclear fission traveling wave reactor, computer software program products for controlling a nuclear fission traveling wave reactor, and nuclear fission traveling wave reactors with systems for migrating fuel assemblies.

Illustrative embodiments provide methods and systems for migrating fuel assemblies in a nuclear fission reactor, methods of operating a nuclear fission traveling wave reactor, methods of controlling a nuclear fission traveling wave reactor, systems for controlling a nuclear fission traveling wave reactor, computer software program products for controlling a nuclear fission traveling wave reactor, and nuclear fission traveling wave reactors with systems for migrating fuel assemblies.

A method for protecting a nuclear reactor includes reconstructing a maximum linear power density released among the fuel rods of the nuclear fuel assemblies of the core; calculating the thermomechanical state and the burnup fraction of the rods; calculating a mechanical stress or deformation energy density in the cladding of one of the rods by using the said reconstructed maximum linear power density, the calculated thermomechanical states and the calculated burnup fractions, by means of a meta-model of a thermomechanical code; comparing the calculated mechanical stress or the calculated deformation energy density with a respective threshold; and stopping the nuclear reactor if the calculated mechanical stress or the calculated deformation energy density exceeds the respective threshold.