A self-powered in-core detector arrangement for measuring flux in a nuclear reactor core includes a first in-core detector and a second in-core detector. The first in-core detector includes a first flux detecting material, a first lead wire extending longitudinally from a first axial end of the first flux detecting material, a first insulating material surrounding outer diameters of the first flux detecting material and the first lead wire and a first sheath surrounding the first insulating material. The first sheath includes a first section surrounding the first flux detecting material and a second section surrounding the first lead wire. The first section of the first sheath has a greater outer diameter than the second section of the first sheath. The second in-core detector includes a second flux detecting material, a second lead wire extending longitudinally from a first axial end of the second flux detecting material, a second insulating material surrounding outer diameters of the second flux detecting material and the second lead wire, and a second sheath surrounding the second insulating material. The second sheath includes a first section surrounding the second flux detecting material and a second section surrounding the second lead wire. The first section of the second sheath has a greater outer diameter than the second section of the second sheath. The first section of the first sheath is axially offset from the first section of the second sheath and radially aligned with the second section of second sheath.

Disclosed herein is a method pertaining to a power distribution of a reactor core of a nuclear installation, the method being executed on a general purpose computer. The method comprises: measuring current values from a plurality of vanadium neutron detector assemblies which are disposed in the reactor core of the nuclear installation; determining a measured relative core power distribution based upon the measured current values; producing a measured core power distribution based upon the measured relative core power distribution; and verifying that the reactor is operating within the licensed core operating limits based at least in part upon the measured core power distribution. Also disclosed herein is a vanadium neutron detector assembly.

Disclosed herein is a method pertaining to a power distribution of a reactor core of a nuclear installation, the method being executed on a general purpose computer. The method comprises: measuring current values from a plurality of vanadium neutron detector assemblies which are disposed in the reactor core of the nuclear installation; determining a measured relative core power distribution based upon the measured current values; producing a measured core power distribution based upon the measured relative core power distribution; and verifying that the reactor is operating within the licensed core operating limits based at least in part upon the measured core power distribution. Also disclosed herein is a vanadium neutron detector assembly.

The present invention relates to a method for extending the lifespan of rhodium measuring devices. To this end, the method comprises the steps of: measuring current signals, expressed in amperes, which are induced by electrons emitted as a result of rhodium, in each rhodium measuring device, undergoing beta decay as a result of absorbing neutrons (S10); on the basis of the current signals, and by using a CECOR program, calculating, for each rhodium burnup, respective positional output values of the individual rhodium measuring devices (S20); calculating, for each rhodium burnup, an optimal output value for all positions (S30); determining a W′ correction constant, or a change in an exponent of an approximate expression of the sensitivity of the rhodium measuring devices (S40); calculating, for each rhodium burnup, respective positional output values of the individual rhodium measuring devices, and checking same by carrying out a comparative analysis between same and the respective positional output values of the rhodium measuring devices, calculated in S20 (S50); and extending the lifespan of usage of the rhodium measuring devices by applying the W′ correction constant, or the exponent of the approximate expression of sensitivity, at the time point when ⅔ or more of the rhodium in the rhodium measuring devices is burned up (S60).

The present invention relates to a method for extending the lifespan of rhodium measuring devices. To this end, the method comprises the steps of: measuring current signals, expressed in amperes, which are induced by electrons emitted as a result of rhodium, in each rhodium measuring device, undergoing beta decay as a result of absorbing neutrons (S10); on the basis of the current signals, and by using a CECOR program, calculating, for each rhodium burnup, respective positional output values of the individual rhodium measuring devices (S20); calculating, for each rhodium burnup, an optimal output value for all positions (S30); determining a W′ correction constant, or a change in an exponent of an approximate expression of the sensitivity of the rhodium measuring devices (S40); calculating, for each rhodium burnup, respective positional output values of the individual rhodium measuring devices, and checking same by carrying out a comparative analysis between same and the respective positional output values of the rhodium measuring devices, calculated in S20 (S50); and extending the lifespan of usage of the rhodium measuring devices by applying the W′ correction constant, or the exponent of the approximate expression of sensitivity, at the time point when ⅔ or more of the rhodium in the rhodium measuring devices is burned up (S60).

An excore detector assembly for measuring flux outside of a nuclear reactor core. The excore detector assembly includes a housing and at least one self-powered detector inside the housing for measuring flux generated by the nuclear reactor core. The at least one self-powered detector 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.

An excore detector assembly for measuring flux outside of a nuclear reactor core. The excore detector assembly includes a housing and at least one self-powered detector inside the housing for measuring flux generated by the nuclear reactor core. The at least one self-powered detector 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.

A method for determining at least one threshold value of at least one operating parameter of a nuclear reactor is implemented by an electronic determination system and includes the steps of determining a first threshold value of a respective operating parameter for an operation of the reactor at a first power; and determining a second threshold value of said parameter for an operation of the reactor at a second power. The operation at the lower power of the first and second powers is an operation continued for a duration of at least 8 hours over a 24-hour sliding window. The method also includes determining a third threshold value of said parameter for an operation of the reactor at a third power between the first power and the second power.

A method for determining at least one threshold value of at least one operating parameter of a nuclear reactor is implemented by an electronic determination system and includes the steps of determining a first threshold value of a respective operating parameter for an operation of the reactor at a first power; and determining a second threshold value of said parameter for an operation of the reactor at a second power. The operation at the lower power of the first and second powers is an operation continued for a duration of at least 8 hours over a 24-hour sliding window. The method also includes determining a third threshold value of said parameter for an operation of the reactor at a third power between the first power and the second power.

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.