Method of producing mixed in-core maps and application to the calibration of fixed instrumentation
AssigneeAreva Np
InventorGérard Rio
Life of this patent
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Abstract
The object of the present invention is a method for establishing so-called “mixed IN-CORE mappings”. Its essential purpose is to compensate a loss of density of a reference instrumentation, called “RIC instrumentation” (or “RIC system”), when a significant number of locations, initially used by the sensors of the RIC system, are occupied by fixed collectron-type rods. An obvious physical interest lies in the increase of the measurement density, and thus of the level of confidence, associated with the operating results deduced from the processing of these measurements. One application of the method according to the invention concerns a collectron-type detector calibration method placed inside a nuclear reactor core.
Claims18
A method of correction for a component of intrinsic uncertainty, associated with a collectron-type detector placed inside a nuclear power plant core, comprising:
- establishing a mapping as a representation of a power distribution inside the nuclear reactor core, said mapping being established by means of a reference instrumentation system, said mapping comprising;
- equipping, at least temporarily, a first set of fuel assemblies of the nuclear reactor core with detectors from said reference instrumentation system;
- equipping, at least temporarily, a second set of fuel assemblies of the nuclear reactor core with detectors from a second instrumentation system;
- performing a first partial series of activity measurements by means of the detectors from said reference instrumentation system;
- performing a second partial series of activity measurements by means of the detectors from the second instrumentation system;
- converting the activity measurements of the second partial series of measurements into activity measurements associated with said reference instrumentation system in order to obtain a series of converted measurements;
- establishing, by way of the first partial series of activity measurements, of the series of converted measurements, of a complete theoretical distribution of the theoretical activities associated with the reference instrumentation system, and of a complete theoretical distribution of the theoretical activities associated with the second instrumentation system, for every instrumented point of the nuclear reactor core, a final series of experimental reactor core activities, said data series only comprising the values relating to the activities associated with the reference instrumentation system;
- and
- establishing, based on the final series of experimental data and of theoretical data simulating a state of the reactor core at the time of the performance of the first partial series of measurements and of the second partial series of measurements, the mapping being representative of a power distribution inside a nuclear reactor core
- performing a calibration operation on a collectron, the calibration operation being performed when the collectron-type detector has reached a given level of wear, the calibration operation consisting of performing a three-dimensional calibration using the mapping.
A method for establishing a mapping representative of a power distribution inside a nuclear reactor core, said mapping being performed by means of detectors placed at least temporarily inside the core of the reactor, the method comprising:
- equipping, at least temporarily, a first set of fuel assemblies of the nuclear reactor core with detectors from a reference instrumentation system;
- equipping, at least temporarily, a second set of fuel assemblies of the nuclear reactor core with detectors from a second instrumentation system;
- performing a first partial series of activity measurements by means of the detectors from said reference instrumentation system;
- performing a second partial series of activity measurements by means of the detectors from the second instrumentation system;
- converting the activity measurements of the second partial series of measurements into activity measurements associated with said reference instrumentation system in order to obtain a series of converted measurements;
- establishing, by way of the first partial series of activity measurements, of the series of converted measurements, of a complete theoretical distribution of the theoretical activities associated with the reference instrumentation system, and of a complete theoretical distribution of the theoretical activities associated with the second instrumentation system, for every instrumented point of the nuclear reactor core, a final series of experimental reactor core activities, said data series only comprising the values relating to the activities associated with the reference instrumentation system;
- and
- establishing, based on the final series of experimental data and of theoretical data simulating a state of the reactor core at the time of the performance of the first partial series of measurements and of the second partial series of measurements, the mapping being representative of a power distribution inside a nuclear reactor core.
Dependencies are inferred from the claim text.