Development of on-line reactivity meter for nuclear reactors

An online reactivity meter which has been developed for continuous monitoring of reactivity in the Pakistan Research Reactor-1 (PARR-1) is described. The theory of the kinetic technique of measuring reactivity, used by the meter, is described. The meter itself consists of hardware and software for online acquisition of neutron flux signals from plant instrumentation channels and high-level Fortran-77 real-time programming for the computation of reactivity by the solution of neuron kinetic equation. The PDP-11/23 plant computer is used to monitor the plant reactor with the time sharing of its regular data logging function. For the PARR-2 reactor the reactivity meter has been implemented with an IBM PC/AT personal computer. The response of both reactivity meters is fast enough to monitor safety-related reactivity and power excursions in the two reactors. The results of various reactivity measurements are described. The proper choice and location of nuclear detectors and system calibration are discussed.<
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