Patent ID: 8445839
Filing Date: 2013-05-21
Classification: G01T,G21C,Y02E

Abstract:
1. A method for calibrating a first self-powered neutron detector with a second self-powered neutron detector for long term use of the first and second self-powered neutron detectors in a nuclear reactor core, the method comprising: exposing at least one pair of self-powered neutron detectors to a neutron flux in a nuclear reactor, each of the self-powered neutron detectors in the pair producing a signal proportional to the same neutron flux; the pair comprising a first self-powered neutron detector and a second self-powered neutron detector; wherein each self-powered neutron detector in the pair comprises an emitter and a collector; the emitter of the first self-powered neutron detector in each pair comprising a first emitter material, and the emitter of the second self-powered neutron detector in each pair comprising a second emitter material; wherein the second emitter material has a neutron absorption cross-section that is greater than the neutron absorption cross-section of the first emitter material; simultaneously measuring the response of each of the first and second self-powered neutron detectors to the same neutron flux in the nuclear reactor core; and calibrating the signal produced by the first self-powered neutron detector in the pair in response to the neutron flux with the signal produced by the second self-powered neutron detector in the pair in response to the neutron flux over a period of time sufficient to determine the thermal neutron sensitivity for the first emitter material for a given emitter depletion.