Abstract: The invention relates to a system for the monitoring and control of the core of a nuclear reactor along which N fission chambers CFi (i=1, 2, . . . , N) are positioned, N being an integer number greater than or equal to 2, in which: computing means (P) are able to compute a statistical estimation of the nth order neutron flux CFi of each fission chamber CFi and a mean value of estimation of the neutron flux that represents the mean neutron flux prevailing in the core of the nuclear reactor, such that = 1 N ? ? i = 1 N ? ? CFi ? ? and computing means (M, CMP) are able to compute an ageing indicator (S) for the fission chamber CFi from the statistical estimation value of the neutron flux CFi of the fission chamber CFi.

Abstract: A method for detecting a radioactive source moving on a linear path substantially parallel to an alignment of N detectors. The method includes: forming N×Nt pulse counting values Mi,t (i=1, 2, . . . , N and t=1, 2, . . . , Nt) from N×Nt detection signals delivered by the N detectors in the form of a succession over time of Nt sets of N signals simultaneously detected by the N detectors over a same duration ?t, a pulse counting value representing a number of pulses detected by a detector over a duration ?t; and computing, using a computer: a set of Nt correlation products Rt, a static mean R of the N×Nt counting values, a correlation condition for each correlation product Rt.

Abstract: The invention relates to a system for the monitoring and control of the core of a nuclear reactor along which N fission chambers CFi (i=1, 2, . . . , N) are positioned, N being an integer number greater than or equal to 2, in which: computing means (P) are able to compute a statistical estimation of the nth order neutron flux CFi of each fission chamber CFi and a mean value of estimation of the neutron flux that represents the mean neutron flux prevailing in the core of the nuclear reactor, such that = 1 N ? ? i = 1 N ? ? CFi ? ? and computing means (M, CMP) are able to compute an ageing indicator (S) for the fission chamber CFi from the statistical estimation value of the neutron flux CFi of the fission chamber CFi.

Abstract: A device for processing signals detected by a set of n neutron detectors, the device including: n switches each including an input and an output, each switch receiving, on its input, a detected signal coming from a different detector, outputs of the n switches being linked to each other; and a clock generator including a clock circuit and a sequential counter controlled by the clock circuit and configured to deliver a plurality of pulse series, each pulse series of the plurality of pulse series constituting a control signal of a different switch, the pulses of any two pulse series of the plurality of pulse series being disjointed.

Abstract: A method for detecting a radioactive source moving on a linear path substantially parallel to an alignment of N detectors. The method includes: forming NxNt pulse counting values Mi,t (i=1, 2, . . . , N and t=1, 2, . . . , Nt) from NxNt detection signals delivered by the N detectors in the form of a succession over time of Nt sets of N signals simultaneously detected by the N detectors over a same duration ?t, a pulse counting value representing a number of pulses detected by a detector over a duration ?t; and computing, using a computer: a set of Nt correlation products Rt, a static mean R of the NxNt counting values, a correlation condition for each correlation product Rt.