A self-powered nuclear radiation detector. The self-powered nuclear radiation detector includes a cable assembly, a temperature compensation assembly, and a metallic outer sheath. The cable assembly includes a metallic signal lead, an insulative material surrounding the metallic signal lead, and a metallic sheath surrounding the insulative material. The temperature compensation assembly includes a second metallic signal lead, a second insulative material surrounding the second metallic signal lead, and a second metallic sheath surrounding the second insulative material. The metallic outer sheath surrounds the cable assembly and the temperature compensation assembly.

An detector-assembly for measuring flux in a nuclear reactor core includes self-powered in-core detector arrangements each for measuring flux at a different one of a plurality of axial locations in the core, and an assembly connector configured to be connected to a power plant connector. The assembly connector includes a plurality flux signal terminals each connected to one of self-powered in-core detector arrangements. At least one of the self-powered in-core detector arrangements comprises a set of at least two self-powered in-core detectors for measuring flux at a same one of the axial locations in the nuclear reactor core. Each of the at least two self-powered in-core detectors includes a sheath, a detector material section inside the sheath, an insulator between the sheath and the detector material, and a flux signal output line. The flux signal output lines of the at least two self-powered in-core detectors are joined together.

The present invention provides apparatuses comprising a plurality of junctions providing a Seebeck effect, configured as alternating hot and cold junctions. The apparatus can be configured such that the cold junctions exhibit a different thermal behavior than the hot junctions in response to incident radiation. The junctions can be connected in series, such that the sum of the Seebeck effect from the plurality of junctions provides a sensitive, inherently calibrated indication of heating of the apparatus responsive to incident radiation, and therefore of the radiation itself.

A measuring device for measuring the activity of a specimen of a radioactive isotope is disclosed. The specimen of the radioactive isotope is contained within a capsule. The measuring device comprises an inner enclosure, a gamma-radiation sensitive self-power detector (SPD) positioned around the inner enclosure, and an outer enclosure positioned around the SPD and the inner enclosure. The inner enclosure comprises an internal cavity configured to receive the capsule containing the specimen. The inner enclosure defines a longitudinal axis. The outer enclosure secures the SPD to the inner enclosure such that the SPD does not move during operation and storage of the measuring device.

A neutron position detector according to an embodiment includes a tubular enclosure used as a cathode, an anode located at an axial center inside the enclosure, and a gas that includes a .sup.3He gas and an additive gas and is sealed inside the enclosure. The additive gas includes nitrogen as a quenching gas, and argon as a gas that reduces the ranges of reaction products as neutron and .sup.3He gas.

A neutron detector is disclosed herein. The neutron detector can include a housing defining a cavity, wherein the housing is configured to permit an amount of neutrons emitted from a core of a nuclear reactor to enter the cavity. The neutron detector can also include an amount of a neutron sensitive material dispositioned within the cavity, wherein the neutron sensitive material is configured to generate and emit gamma rays upon interacting with the amount of neutrons. The neutron detector can further include an amount of electron emissive material configured to generate and emit a current of electrons upon interacting with the emitted gamma rays, wherein the current of electrons is indicative of the amount of neutrons emitted from the core of the nuclear reactor.

A neutron detector is disclosed herein. The neutron detector can include a housing defining a cavity, wherein the housing is configured to permit an amount of neutrons emitted from a core of a nuclear reactor to enter the cavity. The neutron detector can also include an amount of a neutron sensitive material dispositioned within the cavity, wherein the neutron sensitive material is configured to generate and emit gamma rays upon interacting with the amount of neutrons. The neutron detector can further include an amount of electron emissive material configured to generate and emit a current of electrons upon interacting with the emitted gamma rays, wherein the current of electrons is indicative of the amount of neutrons emitted from the core of the nuclear reactor.

A method whereby signals that are output by replacement SPNDs are converted into equivalent signals that would have been detected by legacy SPNDs for input to the legacy software. The replacement SPNDs have a different geometry than the legacy SPNDs and also have a different neutron sensitivity than the legacy SPNDs. The replacement SPNDs are subjected to a neutron flux in a core of a reactor and responsively output a set of signals. The set of signals and the geometry of the replacement SPNDs are employed to create a characterization of the neutron flux in the form of a curve that represents flux as a function of location along the core of the reactor. The legacy geometry of the legacy SPNDs is then employed to find the values on the curve that correspond with the positions where the legacy SPNDs had been located to create inputs for the legacy software.

A radiation imaging apparatus that communicates via wired communication with an irradiation control apparatus includes a radiation detection unit that detects incident radiation and obtains a moving image related to the radiation, and an imaging control unit that, in a first case where the wired communication is disconnected in a moving image capturing state in which the moving image is captured, performs control to set the moving image capturing state, and in a second case where the wired communication is disconnected not in the moving image capturing state and moving image capturing is set as next imaging, performs control to set a moving image standby state that is a standby state for the moving image capturing.

Large detection area, high spatial resolution, high dynamic range and low noise neutron detectors are disclosed. Curved detectors that minimize parallax errors and boundary regions without sacrificing its intrinsic resolution or the efficiency are also disclosed.